Duckweed: Research Meets Applications

A special issue of Plants (ISSN 2223-7747).

Deadline for manuscript submissions: closed (10 October 2022) | Viewed by 113164

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Special Issue Editors

Department of Botany, Institute of Biology and Ecology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary
Interests: duckweed research; plant ecophysiology; aquatic ecotoxicology
Institute of General Botany and Plant Physiology, Friedrich Schiller University Jena, 07743 Jena, Germany
Interests: duckweed research and applications
Department of Environmental Science, Central University of Kerala, Periye 671320, India
Interests: duckweed research and applications
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Special Issue Information

Dear Colleagues,

Duckweeds are the smallest angiosperms belonging to the family Lemnaceae, normally occupying the surface of lentic habitats. As minute and simple organisms, they seem to fascinate generations of scientists with the many secrets they possess. Besides their basic role in aquatic ecosystems, they offer a suitable model for ecologists, physiologists, geneticists, and researchers of many other fields. Moreover, from a practical point of view, they can help in coping with various aspects of the current humanitarian and environmental crisis, serve as indicators or test organisms for environmental monitoring, help in removing water pollutants, and provide valuable biomass for easing the worldwide protein shortage or the hunger for renewable energy. 

The recent bloom of duckweed-related research reflects this versatility and conveys an ever-deepening knowledge on these tiny creatures, sometimes making it difficult, even for experts in the field, to keep up with the pace. The aim of this Special Issue is to provide a comprehensive update of the current progress in duckweed research and applications. Contributions in forms of both original research papers and reviews from a broad scope of disciplines related to duckweed research and applications (e.g., morphology, taxonomy, and ecology including ecological interactions, ecotoxicology, environmental monitoring and remediation, physiology, biochemistry, genetics, omics, biotechnology, biomass production and its uses, etc.) are welcome. We hope that this overview will be of interest to all those involved in basic research or potential applications of duckweeds, and will also attract researchers from various other fields.

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News:

The three guest editors of the SI of Plants participated in the 6th International Conference on Duckweed Research and Applications (ICDRA), held from 29th May to 1st June 2022 in Gatersleben, Germany, for the first time in Europe. The conference was organised by the International Steering Committe on Duckweed Research and Applications (ISCRA) together with the National Academy of Sciences Leopoldina and the Leibnitz Institute of Plant Genetics and Crop Plant Research, both Germany. Finn Petersen, from the Universiy of Applied Sciences, Osnabrueck, Germany, received the award for the best presentation by a PhD student during the 6th ICDRA. The award was sponsored by Plants and presented by the guest editors of the Special Issue "Duckweeds: Research meets Applications", Viktor Olah and Klaus-J. Appenroth (left in the photo). The guest editors revealed the extension to the deadline of the Special Issue "Duckweeds: Research meets Applications" until 10 October 2022.

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Best PhD presentation for Finn Petersen: Viktor Olah and Klaus-J. Appenroth (left).

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Guest editors: On the photo from left to right: Klaus-J. Appenroth, Member of the ISCDRA, Germany; K. Sowjanya Sree, Member of the ISCRA, India; Viktor Olah, Member of the Editorial Board of MDPI Plants, Hungary.

Dr. Viktor Oláh
Dr. Klaus-Jürgen Appenroth
Dr. K. Sowjanya Sree
Guest Editors

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Keywords

  • duckweed
  • Lemnaceae
  • physiology
  • genetics
  • omics
  • phylogenetics
  • ecology
  • ecotoxicology
  • remediation
  • biomass

Published Papers (39 papers)

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Editorial

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8 pages, 1692 KiB  
Editorial
Duckweed: Research Meets Applications
by Viktor Oláh, Klaus-Juergen Appenroth and K. Sowjanya Sree
Plants 2023, 12(18), 3307; https://doi.org/10.3390/plants12183307 - 19 Sep 2023
Viewed by 1297
Abstract
The Special Issue “Duckweed: Research Meets Applications” of the journal Plants (ISSN 2223-7747) presents a comprehensive update of the current progress in the field [...] Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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Research

Jump to: Editorial, Review, Other

17 pages, 3714 KiB  
Article
Characterisation of a Spontaneous Mutant of Lemna gibba G3 (Lemnaceae)
by Lakshmi Pasricha Sarin, K. Sowjanya Sree, Károly Bóka, Áron Keresztes, Jörg Fuchs, Akhilesh K. Tyagi, Jitendra Paul Khurana and Klaus-Juergen Appenroth
Plants 2023, 12(13), 2525; https://doi.org/10.3390/plants12132525 - 02 Jul 2023
Cited by 3 | Viewed by 1138
Abstract
A spontaneous mutant of the duckweed Lemna gibba clone no. 7796 (known as strain G3, WT) was discovered. In this mutant clone, L. gibba clone no. 9602 (mt), the morphological parameters (frond length, frond width, root length, root diameter) indicated an enlarged size. [...] Read more.
A spontaneous mutant of the duckweed Lemna gibba clone no. 7796 (known as strain G3, WT) was discovered. In this mutant clone, L. gibba clone no. 9602 (mt), the morphological parameters (frond length, frond width, root length, root diameter) indicated an enlarged size. A change in the frond shape was indicated by the decreased frond length/width ratio, which could have taxonomic consequences. Several different cell types in both the frond and the root were also enlarged. Flow cytometric measurements disclosed the genome size of the WT as 557 Mbp/1C and that of the mt strain as 1153 Mbp/1C. This represents the results of polyploidisation of a diploid clone to a tetraploid one. The mutant clone flowered under the influence of long day-treatment in half-strength Hutner’s medium in striking contrast to the diploid WT. Low concentration of salicylic acid (<1 µM) induced flowering in the tetraploid mutant but not in the diploid plants. The transcript levels of nuclear-encoded genes of the photosynthetic apparatus (CAB, RBCS) showed higher abundance in light and less dramatic decline in darkness in the mt than in WT, while this was not the case with plastid-encoded genes (RBCL, PSAA, PSBA, PSBC). Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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16 pages, 6565 KiB  
Article
Overexpression of the Phosphoserine Phosphatase-Encoding Gene (AtPSP1) Promotes Starch Accumulation in Lemna turionifera 5511 under Sulfur Deficiency
by Lei Wang, Yingying Kuang, Siyu Zheng, Yana Tong, Yerong Zhu and Yong Wang
Plants 2023, 12(5), 1012; https://doi.org/10.3390/plants12051012 - 23 Feb 2023
Cited by 2 | Viewed by 1213
Abstract
Duckweeds are well known for their high accumulation of starch under stress conditions, along with inhibited growth. The phosphorylation pathway of serine biosynthesis (PPSB) was reported as playing a vital role in linking the carbon, nitrogen, and sulfur metabolism in this plant. The [...] Read more.
Duckweeds are well known for their high accumulation of starch under stress conditions, along with inhibited growth. The phosphorylation pathway of serine biosynthesis (PPSB) was reported as playing a vital role in linking the carbon, nitrogen, and sulfur metabolism in this plant. The overexpression of AtPSP1, the last key enzyme of the PPSB pathway in duckweed, was found to stimulate the accumulation of starch under sulfur-deficient conditions. The growth- and photosynthesis-related parameters were higher in the AtPSP1 transgenic plants than in the WT. The transcriptional analysis showed that the expression of several genes in starch synthesis, TCA, and sulfur absorption, transportation, and assimilation was significantly up- or downregulated. The study suggests that PSP engineering could improve starch accumulation in Lemna turionifera 5511 by coordinating the carbon metabolism and sulfur assimilation under sulfur-deficient conditions. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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26 pages, 2257 KiB  
Article
Optimization of Molecular Methods for Detecting Duckweed-Associated Bacteria
by Kenneth Acosta, Shawn Sorrels, William Chrisler, Weijuan Huang, Sarah Gilbert, Thomas Brinkman, Todd P. Michael, Sarah L. Lebeis and Eric Lam
Plants 2023, 12(4), 872; https://doi.org/10.3390/plants12040872 - 15 Feb 2023
Cited by 2 | Viewed by 2577
Abstract
The bacterial colonization dynamics of plants can differ between phylogenetically similar bacterial strains and in the context of complex bacterial communities. Quantitative methods that can resolve closely related bacteria within complex communities can lead to a better understanding of plant–microbe interactions. However, current [...] Read more.
The bacterial colonization dynamics of plants can differ between phylogenetically similar bacterial strains and in the context of complex bacterial communities. Quantitative methods that can resolve closely related bacteria within complex communities can lead to a better understanding of plant–microbe interactions. However, current methods often lack the specificity to differentiate phylogenetically similar bacterial strains. In this study, we describe molecular strategies to study duckweed–associated bacteria. We first systematically optimized a bead-beating protocol to co-isolate nucleic acids simultaneously from duckweed and bacteria. We then developed a generic fingerprinting assay to detect bacteria present in duckweed samples. To detect specific duckweed–bacterium associations, we developed a genomics-based computational pipeline to generate bacterial strain-specific primers. These strain-specific primers differentiated bacterial strains from the same genus and enabled the detection of specific duckweed–bacterium associations present in a community context. Moreover, we used these strain-specific primers to quantify the bacterial colonization of duckweed by normalization to a plant reference gene and revealed differences in colonization levels between strains from the same genus. Lastly, confocal microscopy of inoculated duckweed further supported our PCR results and showed bacterial colonization of the duckweed root–frond interface and root interior. The molecular methods introduced in this work should enable the tracking and quantification of specific plant-microbe associations within plant-microbial communities. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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20 pages, 3164 KiB  
Article
Ammonium Uptake, Mediated by Ammonium Transporters, Mitigates Manganese Toxicity in Duckweed, Spirodela polyrhiza
by Olena Kishchenko, Anton Stepanenko, Tatsiana Straub, Yuzhen Zhou, Benjamin Neuhäuser and Nikolai Borisjuk
Plants 2023, 12(1), 208; https://doi.org/10.3390/plants12010208 - 03 Jan 2023
Cited by 6 | Viewed by 2022
Abstract
Nitrogen is an essential nutrient that affects all aspects of the growth, development and metabolic responses of plants. Here we investigated the influence of the two major sources of inorganic nitrogen, nitrate and ammonium, on the toxicity caused by excess of Mn in [...] Read more.
Nitrogen is an essential nutrient that affects all aspects of the growth, development and metabolic responses of plants. Here we investigated the influence of the two major sources of inorganic nitrogen, nitrate and ammonium, on the toxicity caused by excess of Mn in great duckweed, Spirodela polyrhiza. The revealed alleviating effect of ammonium on Mn-mediated toxicity, was complemented by detailed molecular, biochemical and evolutionary characterization of the species ammonium transporters (AMTs). Four genes encoding AMTs in S. polyrhiza, were classified as SpAMT1;1, SpAMT1;2, SpAMT1;3 and SpAMT2. Functional testing of the expressed proteins in yeast and Xenopus oocytes clearly demonstrated activity of SpAMT1;1 and SpAMT1;3 in transporting ammonium. Transcripts of all SpAMT genes were detected in duckweed fronds grown in cultivation medium, containing a physiological or 50-fold elevated concentration of Mn at the background of nitrogen or a mixture of nitrate and ammonium. Each gene demonstrated an individual expression pattern, revealed by RT-qPCR. Revealing the mitigating effect of ammonium uptake on manganese toxicity in aquatic duckweed S. polyrhiza, the study presents a comprehensive analysis of the transporters involved in the uptake of ammonium, shedding a new light on the interactions between the mechanisms of heavy metal toxicity and the regulation of the plant nitrogen metabolism. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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13 pages, 4455 KiB  
Article
Effects of Microplastic Contamination on the Aquatic Plant Lemna minuta (Least Duckweed)
by Simona Ceschin, Flaminia Mariani, Dario Di Lernia, Iole Venditti, Emanuele Pelella and Maria Adelaide Iannelli
Plants 2023, 12(1), 207; https://doi.org/10.3390/plants12010207 - 03 Jan 2023
Cited by 9 | Viewed by 3573
Abstract
Microplastics are widely spread in aquatic environments. Although they are considered among the most alarming contaminants, toxic effects on organisms are unclear, particularly on freshwater plants. In this study, the duckweed Lemna minuta was grown on different concentrations (50, 100 mg/L) of poly(styrene-co-methyl [...] Read more.
Microplastics are widely spread in aquatic environments. Although they are considered among the most alarming contaminants, toxic effects on organisms are unclear, particularly on freshwater plants. In this study, the duckweed Lemna minuta was grown on different concentrations (50, 100 mg/L) of poly(styrene-co-methyl methacrylate) microplastics (MP) and exposure times (T0, T7, T14, T28 days). The phytotoxic effects of MP were investigated by analyzing several plant morphological and biochemical parameters (frond and root size, plant growth, chlorophyll, and malondialdehyde content). Observations by scanning electron microscope revealed MP adsorption on plant surfaces. Exposition to MP adversely affected plant growth and chlorophyll content with respect to both MP concentrations and exposure times. Conversely, malondialdehyde measurements did not indicate an alteration of oxidative lipid damage in plant tissue. The presence of MP induced root elongation when compared to the control plants. The effects of MP on L. minuta plants were more evident at T28. These results contribute to a better understanding of MP’s impact on aquatic plants and highlight that MP contamination manifests with chronic-type effects, which are thus detectable at longer exposure times of 7 days than those traditionally used in phytotoxicology tests on duckweeds. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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16 pages, 5788 KiB  
Article
Species- and Metal-Specific Responses of the Ionome of Three Duckweed Species under Chromate and Nickel Treatments
by Viktor Oláh, Muhammad Irfan, Zsuzsanna Barnáné Szabó, Zsófi Sajtos, Ágota Zsófia Ragyák, Boglárka Döncző, Marcel A. K. Jansen, Sándor Szabó and Ilona Mészáros
Plants 2023, 12(1), 180; https://doi.org/10.3390/plants12010180 - 01 Jan 2023
Cited by 4 | Viewed by 1630
Abstract
In this study, growth and ionomic responses of three duckweed species were analyzed, namely Lemna minor, Landoltia punctata, and Spirodela polyrhiza, were exposed for short-term periods to hexavalent chromium or nickel under laboratory conditions. It was found that different duckweed [...] Read more.
In this study, growth and ionomic responses of three duckweed species were analyzed, namely Lemna minor, Landoltia punctata, and Spirodela polyrhiza, were exposed for short-term periods to hexavalent chromium or nickel under laboratory conditions. It was found that different duckweed species had distinct ionomic patterns that can change considerably due to metal treatments. The results also show that, because of the stress-induced increase in leaf mass-to-area ratio, the studied species showed different order of metal uptake efficiency if plant area was used as unit of reference instead of the traditional dry weight-based approach. Furthermore, this study revealed that μXRF is applicable in mapping elemental distributions in duckweed fronds. By using this method, we found that within-frond and within-colony compartmentation of metallic ions were strongly metal- and in part species-specific. Analysis of duckweed ionomics is a valuable approach in exploring factors that affect bioaccumulation of trace pollutants by these plants. Apart from remediating industrial effluents, this aspect will gain relevance in food and feed safety when duckweed biomass is produced for nutritional purposes. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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12 pages, 2478 KiB  
Article
Examination of the Metallothionein Gene Family in Greater Duckweed Spirodela polyrhiza
by Orathai Pakdee, Shomo Tshering, Prayad Pokethitiyook and Metha Meetam
Plants 2023, 12(1), 125; https://doi.org/10.3390/plants12010125 - 27 Dec 2022
Cited by 2 | Viewed by 1263
Abstract
Duckweeds are aquatic plants that proliferate rapidly in a wide range of freshwaters, and they are regarded as a potential source of sustainable biomass for various applications and the cost-effective bioremediation of heavy metal pollutants. To understand the cellular and molecular basis that [...] Read more.
Duckweeds are aquatic plants that proliferate rapidly in a wide range of freshwaters, and they are regarded as a potential source of sustainable biomass for various applications and the cost-effective bioremediation of heavy metal pollutants. To understand the cellular and molecular basis that underlies the high metal tolerance and accumulation capacity of duckweeds, we examined the forms and transcript profiles of the metallothionein (MT) gene family in the model duckweed Spirodela polyrhiza, whose genome has been completely sequenced. Four S. polyrhiza MT-like genes were identified and annotated as SpMT2a, SpMT2b, SpMT3, and SpMT4. All except SpMT2b showed high sequence homology including the conserved cysteine residues with the previously described MTs from flowering plants. The S. polyrhiza genome appears to lack the root-specific Type 1 MT. The transcripts of SpMT2a, SpMT2b, and SpMT3 could be detected in the vegetative whole-plant tissues. The transcript abundance of SpMT2a was upregulated several-fold in response to cadmium stress, and the heterologous expression of SpMT2a conferred copper and cadmium tolerance to the metal-sensitive ∆cup1 strain of Saccharomyces cerevisiae. Based on these results, we proposed that SpMT2a may play an important role in the metal detoxification mechanism of duckweed. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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13 pages, 2087 KiB  
Article
Diversity and Differentiation of Duckweed Species from Israel
by Avital Friedjung Yosef, Lusine Ghazaryan, Linda Klamann, Katherine Sarah Kaufman, Capucine Baubin, Ben Poodiack, Noya Ran, Talia Gabay, Shoshana Didi-Cohen, Manuela Bog, Inna Khozin-Goldberg and Osnat Gillor
Plants 2022, 11(23), 3326; https://doi.org/10.3390/plants11233326 - 01 Dec 2022
Cited by 4 | Viewed by 1656
Abstract
Duckweeds (Lemnaceae) are tiny plants that float on aquatic surfaces and are typically isolated from temperate and equatorial regions. Yet, duckweed diversity in Mediterranean and arid regions has been seldom explored. To address this gap in knowledge, we surveyed duckweed diversity in Israel, [...] Read more.
Duckweeds (Lemnaceae) are tiny plants that float on aquatic surfaces and are typically isolated from temperate and equatorial regions. Yet, duckweed diversity in Mediterranean and arid regions has been seldom explored. To address this gap in knowledge, we surveyed duckweed diversity in Israel, an ecological junction between Mediterranean and arid climates. We searched for duckweeds in the north and center of Israel on the surface of streams, ponds and waterholes. We collected and isolated 27 duckweeds and characterized their morphology, molecular barcodes (atpF-atpH and psbK-psbI) and biochemical features (protein content and fatty acids composition). Six species were identified—Lemna minor, L. gibba and Wolffia arrhiza dominated the duckweed populations, and together with past sightings, are suggested to be native to Israel. The fatty acid profiles and protein content further suggest that diverged functions have attributed to different haplotypes among the identified species. Spirodela polyrhiza, W. globosa and L. minuta were also identified but were rarer. S. polyrhiza was previously reported in our region, thus, its current low abundance should be revisited. However, L. minuta and W. globosa are native to America and Far East Asia, respectively, and are invasive in Europe. We hypothesize that they may be invasive species to our region as well, carried by migratory birds that disperse them through their migration routes. This study indicates that the duckweed population in Israel’s aquatic environments consists of both native and transient species. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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7 pages, 584 KiB  
Communication
The Effects of Microbiota on the Herbivory Resistance of the Giant Duckweed Are Plant Genotype-Dependent
by Martin Schäfer and Shuqing Xu
Plants 2022, 11(23), 3317; https://doi.org/10.3390/plants11233317 - 01 Dec 2022
Cited by 3 | Viewed by 1140
Abstract
In nature, all plants live with microbes, which can directly affect their host plants’ physiology and metabolism, as well as their interacting partners, such as herbivores. However, to what extent the microbiota shapes the adaptive evolution to herbivory is unclear. To address this [...] Read more.
In nature, all plants live with microbes, which can directly affect their host plants’ physiology and metabolism, as well as their interacting partners, such as herbivores. However, to what extent the microbiota shapes the adaptive evolution to herbivory is unclear. To address this challenge, it is essential to quantify the intra-specific variations of microbiota effects on plant fitness. Here, we quantified the fitness effects of microbiota on the growth, tolerance, and resistance to herbivory among six genotypes of the giant duckweed, Spirodela polyrhiza. We found that the plant genotypes differed in their intrinsic growth rate and tolerance, but not in their resistance to a native herbivore, the great pond snail. Inoculation with microbiota associated with S. polyrhiza growing outdoors reduced the growth rate and tolerance in all genotypes. Additionally, the microbiota treatment altered the herbivory resistance in a genotype-specific manner. Together, these data show the potential of microbiota in shaping the adaptive evolution of plants. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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21 pages, 3065 KiB  
Article
The Impact of Salt Accumulation on the Growth of Duckweed in a Continuous System for Pig Manure Treatment
by Marie Lambert, Reindert Devlamynck, Marcella Fernandes de Souza, Jan Leenknegt, Katleen Raes, Mia Eeckhout and Erik Meers
Plants 2022, 11(23), 3189; https://doi.org/10.3390/plants11233189 - 22 Nov 2022
Cited by 3 | Viewed by 1934
Abstract
Duckweed (Lemna) is a possible solution for the treatment of aqueous waste streams and the simultaneous provision of protein-rich biomass. Nitrification-Denitrification effluent (NDNE) from pig manure treatment has been previously used as a growing medium for duckweed. This study investigated the [...] Read more.
Duckweed (Lemna) is a possible solution for the treatment of aqueous waste streams and the simultaneous provision of protein-rich biomass. Nitrification-Denitrification effluent (NDNE) from pig manure treatment has been previously used as a growing medium for duckweed. This study investigated the use of a continuous duckweed cultivation system to treat NDNE as a stand-alone technology. For this purpose, a system with a continuous supply of waste streams from the pig manure treatment, continuous biomass production, and continuous discharge that meets the legal standards in Flanders (Belgium) was simulated for a 175-day growing season. In this simulation, salt accumulation was taken into account. To prevent accumulating salts from reaching a toxic concentration and consequently inhibiting growth, the cultivation system must be buffered, which can be achieved by altering the depth of the system. To determine the minimum depth of such a system, a tray experiment was set up. For that, salt accumulation data obtained from previous research were used for simulating systems with different pond depths. It was found that a depth of at least 1 m is needed to prevent a significant relative growth inhibition at the end of the growing season compared to the start. This implies a high water consumption (5–10 times more than maize). As a response, a second cultivation system was investigated for the use of more concentrated NDNE. For this purpose, salt tolerance experiments were conducted on synthetic and biological media. Surprisingly, it was observed that duckweed grows better on diluted NDNE (to 75% NDNE, or EC of 8 mS/cm) than on a synthetic medium (EC of 1.5 mS/cm), indicating the potential of such a system. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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17 pages, 4508 KiB  
Article
Integrated Multitrophic Aquaculture; Analysing Contributions of Different Biological Compartments to Nutrient Removal in a Duckweed-Based Water Remediation System
by Simona Paolacci, Vlastimil Stejskal, Damien Toner and Marcel A. K. Jansen
Plants 2022, 11(22), 3103; https://doi.org/10.3390/plants11223103 - 15 Nov 2022
Cited by 3 | Viewed by 1380
Abstract
Duckweed (Lemnaceae) can support the development of freshwater aquaculture if used as extractive species in Integrated MultiTrophic Aquaculture (IMTA) systems. These aquatic plants have the advantage of producing protein-rich biomass that has several potential uses. On the contrary, other biological compartments, such as [...] Read more.
Duckweed (Lemnaceae) can support the development of freshwater aquaculture if used as extractive species in Integrated MultiTrophic Aquaculture (IMTA) systems. These aquatic plants have the advantage of producing protein-rich biomass that has several potential uses. On the contrary, other biological compartments, such as microalgae and bacteria, present in the water and competing with duckweed for light and nutrients cannot be harvested easily from the water. Moreover, as phytoplankton cannot easily be harvested, nutrients are eventually re-released; hence, this compartment does not contribute to the overall water remediation process. In the present study, a mesocosm experiment was designed to quantify the portion of nutrients effectively removed by duckweed in a duckweed-based aquaculture wastewater remediation system. Three tanks were buried next to a pilot-scale IMTA system used for the production of rainbow trout and perch. The tanks received aquaculture effluents from the adjacent system, and 50% of their surface was covered by duckweed. Daily water analyses of samples at the inlet and outlet of the mesocosm allowed quantification of the amount of nutrients removed in total. The portion removed by duckweed was determined by examining the nutrient content in the initial and final biomass. The portion of nutrients removed by other compartments was similarly estimated. The results show that duckweed is responsible for the removal of 31% and 29% of N and P, respectively. Phytoplankton removed 33% and 38% of N and P, respectively, while the biofilm played no major role in nutrient removal. The remainder of the removed nutrients were probably assimilated by bacteria or sedimented. It is speculated that a higher initial duckweed density can limit phytoplankton growth and, therefore, increase the portion of nutrients removed by the duckweed compartment. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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12 pages, 2061 KiB  
Article
Strategies for Intraspecific Genotyping of Duckweed: Comparison of Five Orthogonal Methods Applied to the Giant Duckweed Spirodela polyrhiza
by Manuela Bog, Luca Braglia, Laura Morello, Karen I. Noboa Melo, Ingo Schubert, Oleg N. Shchepin, K. Sowjanya Sree, Shuqing Xu, Eric Lam and Klaus J. Appenroth
Plants 2022, 11(22), 3033; https://doi.org/10.3390/plants11223033 - 09 Nov 2022
Cited by 4 | Viewed by 1575
Abstract
The predominantly vegetative propagating duckweeds are of growing commercial interest. Since clonal accessions within a respective species can vary considerably with respect to their physiological as well as biochemical traits, it is critical to be able to track the clones of species of [...] Read more.
The predominantly vegetative propagating duckweeds are of growing commercial interest. Since clonal accessions within a respective species can vary considerably with respect to their physiological as well as biochemical traits, it is critical to be able to track the clones of species of interest after their characterization. Here, we compared the efficacy of five different genotyping methods for Spirodela polyrhiza, a species with very low intraspecific sequence variations, including polymorphic NB-ARC-related loci, tubulin-gene-based polymorphism (TBP), simple sequence repeat variations (SSR), multiplexed ISSR genotyping by sequencing (MIG-seq), and low-coverage, reduced-representation genome sequencing (GBS). Four of the five approaches could distinguish 20 to 22 genotypes out of the 23 investigated clones, while TBP resolved just seven genotypes. The choice for a particular method for intraspecific genotyping can depend on the research question and the project budget, while the combination of orthogonal methods may increase the confidence and resolution for the results obtained. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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13 pages, 1884 KiB  
Article
Cultivation of Lemna Minor on Industry-Derived, Anaerobically Digested, Dairy Processing Wastewater
by Rachel O’Mahoney, Neil E. Coughlan, Éamonn Walsh and Marcel A. K. Jansen
Plants 2022, 11(22), 3027; https://doi.org/10.3390/plants11223027 - 09 Nov 2022
Cited by 5 | Viewed by 1081
Abstract
The growth and nutrient uptake capacity of a common duckweed (Lemnaceae) species, Lemna minor “Blarney”, on dairy processing wastewater pre-treated by an anaerobic digester (AD-DPW) was explored. L. minor was cultivated in small stationary vessels in a controlled indoor environment, as well as [...] Read more.
The growth and nutrient uptake capacity of a common duckweed (Lemnaceae) species, Lemna minor “Blarney”, on dairy processing wastewater pre-treated by an anaerobic digester (AD-DPW) was explored. L. minor was cultivated in small stationary vessels in a controlled indoor environment, as well as in a semi-outdoor 35 L recirculatory system. The use of AD-DPW as a cultivation medium for L. minor offers a novel approach to dairy wastewater treatment, evolving from the current resource-intensive clean-up of wastewaters to duckweed-based valorisation, simultaneously generating valuable plant biomass and remediating the wastewater. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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11 pages, 1269 KiB  
Article
The Response of Duckweed Lemna minor to Microplastics and Its Potential Use as a Bioindicator of Microplastic Pollution
by Ula Rozman and Gabriela Kalčíková
Plants 2022, 11(21), 2953; https://doi.org/10.3390/plants11212953 - 02 Nov 2022
Cited by 15 | Viewed by 2996
Abstract
Biomonitoring has become an indispensable tool for detecting various environmental pollutants, but microplastics have been greatly neglected in this context. They are currently monitored using multistep physico-chemical methods that are time-consuming and expensive, making the search for new monitoring options of great interest. [...] Read more.
Biomonitoring has become an indispensable tool for detecting various environmental pollutants, but microplastics have been greatly neglected in this context. They are currently monitored using multistep physico-chemical methods that are time-consuming and expensive, making the search for new monitoring options of great interest. In this context, the aim of this study was to investigate the possibility of using an aquatic macrophyte as a bioindicator of microplastic pollution in freshwaters. Therefore, the effects and adhesion of three types of microplastics (polyethylene microbeads, tire wear particles, and polyethylene terephthalate fibers) and two types of natural particles (wood dust and cellulose particles) to duckweed Lemna minor were investigated. The results showed that fibers and natural particles had no effect on the specific growth rate, chlorophyll a content, and root length of duckweed, while a significant reduction in the latter was observed when duckweed was exposed to microbeads and tire wear particles. The percentage of adhered particles was ten times higher for polyethylene microbeads than for other microplastics and natural particles, suggesting that the adhesion of polyethylene microbeads to duckweed is specific. Because the majority of microplastics in freshwaters are made of polyethylene, the use of duckweed for their biomonitoring could provide important information on microplastic pollution in freshwaters. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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14 pages, 3414 KiB  
Article
Dynamic Alteration of Microbial Communities of Duckweeds from Nature to Nutrient-Deficient Condition
by Chakrit Bunyoo, Peerapat Roongsattham, Sirikorn Khumwan, Juthaporn Phonmakham, Passorn Wonnapinij and Arinthip Thamchaipenet
Plants 2022, 11(21), 2915; https://doi.org/10.3390/plants11212915 - 29 Oct 2022
Cited by 7 | Viewed by 1983
Abstract
Duckweeds live with complex assemblages of microbes as holobionts that play an important role in duckweed growth and phytoremediation ability. In this study, the structure and diversity of duckweed-associated bacteria (DAB) among four duckweed subtypes under natural and nutrient-deficient conditions were investigated using [...] Read more.
Duckweeds live with complex assemblages of microbes as holobionts that play an important role in duckweed growth and phytoremediation ability. In this study, the structure and diversity of duckweed-associated bacteria (DAB) among four duckweed subtypes under natural and nutrient-deficient conditions were investigated using V3-V4 16S rRNA amplicon sequencing. High throughput sequencing analysis indicated that phylum Proteobacteria was predominant in across duckweed samples. A total of 24 microbial genera were identified as a core microbiome that presented in high abundance with consistent proportions across all duckweed subtypes. The most abundant microbes belonged to the genus Rhodobacter, followed by other common DAB, including Acinetobacter, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, and Pseudomonas. After nutrient-deficient stress, diversity of microbial communities was significantly deceased. However, the relative abundance of Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Pelomonas, Roseateles and Novosphingobium were significantly enhanced in stressed duckweeds. Functional prediction of the metagenome data displayed the relative abundance of essential pathways involved in DAB colonization, such as bacterial motility and biofilm formation, as well as biodegradable ability, such as benzoate degradation and nitrogen metabolism, were significantly enriched under stress condition. The findings improve the understanding of the complexity of duckweed microbiomes and facilitate the establishment of a stable microbiome used for co-cultivation with duckweeds for enhancement of biomass and phytoremediation under environmental stress. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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8 pages, 2651 KiB  
Communication
Chromosome Numbers and Genome Sizes of All 36 Duckweed Species (Lemnaceae)
by Phuong T. N. Hoang, Jörg Fuchs, Veit Schubert, Tram B. N. Tran and Ingo Schubert
Plants 2022, 11(20), 2674; https://doi.org/10.3390/plants11202674 - 11 Oct 2022
Cited by 7 | Viewed by 1736
Abstract
Usually, chromosome sets (karyotypes) and genome sizes are rather stable for distinct species and therefore of diagnostic value for taxonomy. In combination with (cyto)genomics, both features provide essential cues for genome evolution and phylogenetic relationship studies within and between taxa above the species [...] Read more.
Usually, chromosome sets (karyotypes) and genome sizes are rather stable for distinct species and therefore of diagnostic value for taxonomy. In combination with (cyto)genomics, both features provide essential cues for genome evolution and phylogenetic relationship studies within and between taxa above the species level. We present for the first time a survey on chromosome counts and genome size measurement for one or more accessions from all 36 duckweed species and discuss the evolutionary impact and peculiarities of both parameters in duckweeds. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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20 pages, 3293 KiB  
Article
Flow Rate and Water Depth Alters Biomass Production and Phytoremediation Capacity of Lemna minor
by Neil E. Coughlan, Éamonn Walsh, Roger Ahern, Gavin Burnell, Rachel O’Mahoney, Holger Kuehnhold and Marcel A. K. Jansen
Plants 2022, 11(16), 2170; https://doi.org/10.3390/plants11162170 - 21 Aug 2022
Cited by 6 | Viewed by 2564
Abstract
Given its high biomass production, phytoremediation capacity and suitability as a feedstock for animal and human nutrition, duckweeds are valuable multipurpose plants that can underpin circular economy applications. In recent years, the use of duckweeds to mitigate environmental pollution and valorise wastewaters through [...] Read more.
Given its high biomass production, phytoremediation capacity and suitability as a feedstock for animal and human nutrition, duckweeds are valuable multipurpose plants that can underpin circular economy applications. In recent years, the use of duckweeds to mitigate environmental pollution and valorise wastewaters through the removal of excess nitrogen and phosphate from wastewaters has gained considerable scientific attention. However, quantitative data on optimisation of duckweed performance in phytoremediation systems remain scant. In particular, a mechanistical understanding of how physical flows affect duckweed growth and remediation capacity within vertical indoor multi-tiered bioreactors is unknown. Here, effects of flow rate (0.5, 1.5 or 3.0 L min−1) and medium depth (25 mm or 50 mm) on Lemna minor biomass production and phytoremediation capacity were investigated. Results show that flow rates and water depths significantly affect both parameters. L. minor grew best at 1.5 L min−1 maintained at 50 mm, corresponding to a flow velocity of 0.0012 m s−1. The data are interpreted to mean that flow velocities should be low enough not to physically disturb duckweed but still allow for adequate nutrient mixing. The data presented will considerably advance the optimisation of large-scale indoor (multi-tiered, stacked), as well as outdoor (pond, lagoon, canal), duckweed-based remediation of high nutrient wastewaters. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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11 pages, 1140 KiB  
Article
A Machine-Learning Method to Assess Growth Patterns in Plants of the Family Lemnaceae
by Leone Ermes Romano, Maurizio Iovane, Luigi Gennaro Izzo and Giovanna Aronne
Plants 2022, 11(15), 1910; https://doi.org/10.3390/plants11151910 - 23 Jul 2022
Cited by 4 | Viewed by 1948
Abstract
Numerous new technologies have been implemented in image analysis methods that help researchers draw scientific conclusions from biological phenomena. Plants of the family Lemnaceae (duckweeds) are the smallest flowering plants in the world, and biometric measurements of single plants and their growth rate [...] Read more.
Numerous new technologies have been implemented in image analysis methods that help researchers draw scientific conclusions from biological phenomena. Plants of the family Lemnaceae (duckweeds) are the smallest flowering plants in the world, and biometric measurements of single plants and their growth rate are highly challenging. Although the use of software for digital image analysis has changed the way scientists extract phenomenological data (also for studies on duckweeds), the procedure is often not wholly automated and sometimes relies on the intervention of a human operator. Such a constraint can limit the objectivity of the measurements and generally slows down the time required to produce scientific data. Herein lies the need to implement image analysis software with artificial intelligence that can substitute the human operator. In this paper, we present a new method to study the growth rates of the plants of the Lemnaceae family based on the application of machine-learning procedures to digital image analysis. The method is compared to existing analogical and computer-operated procedures. The results showed that our method drastically reduces the time consumption of the human operator while retaining a high correlation in the growth rates measured with other procedures. As expected, machine-learning methods applied to digital image analysis can overcome the constraints of measuring growth rates of very small plants and might help duckweeds gain worldwide attention thanks to their strong nutritional qualities and biological plasticity. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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18 pages, 1379 KiB  
Article
Effect of 17β-Estradiol on Growth and Biosynthesis of Microalgae Scenedesmus quadricauda (CPCC-158) and Duckweed Lemna minor (CPCC-490) Grown in Three Different Media
by Tatiana A. Kozlova and David B. Levin
Plants 2022, 11(13), 1669; https://doi.org/10.3390/plants11131669 - 24 Jun 2022
Cited by 3 | Viewed by 1483
Abstract
As fish farm wastewaters have detectable levels of fish hormones, such as 17β-estradiol (E2), an understanding of the influence of fish steroids on algal (Scenedesmus quadricauda) and duckweed (Lemna minor) physiology is relevant to the potential use of [...] Read more.
As fish farm wastewaters have detectable levels of fish hormones, such as 17β-estradiol (E2), an understanding of the influence of fish steroids on algal (Scenedesmus quadricauda) and duckweed (Lemna minor) physiology is relevant to the potential use of fishery wastewaters for microalgae and plant biomass production. The study was conducted using three types of media: Bold Basal Medium (BBM), natural fishery wastewater (FWW), and reconstituted fishery wastewater (RFWW) with the nutrient composition adjusted to mimic FWW. During the experiment, the media were aerated and changes in the pH and conductivity of the water were closely monitored. E2 promoted the growth of S. quadricauda and L. minor, with significant accumulation of high-value biomolecules at very low steroid concentrations. However, clear differences in growth performance were observed in both test cultures, S. quadricauda and L. minor, grown in different media, and the most effective hormone concentrations were evidently different for the algae and the plant. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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14 pages, 16573 KiB  
Article
Biodiversity of Duckweed (Lemnaceae) in Water Reservoirs of Ukraine and China Assessed by Chloroplast DNA Barcoding
by Guimin Chen, Anton Stepanenko, Olha Lakhneko, Yuzhen Zhou, Olena Kishchenko, Anton Peterson, Dandan Cui, Haotian Zhu, Jianming Xu, Bogdan Morgun, Dmitri Gudkov, Nikolai Friesen and Mykola Borysyuk
Plants 2022, 11(11), 1468; https://doi.org/10.3390/plants11111468 - 30 May 2022
Cited by 5 | Viewed by 3567
Abstract
Monitoring and characterizing species biodiversity is essential for germplasm preservation, academic studies, and various practical applications. Duckweeds represent a group of tiny aquatic plants that include 36 species divided into 5 genera within the Lemnaceae family. They are an important part of aquatic [...] Read more.
Monitoring and characterizing species biodiversity is essential for germplasm preservation, academic studies, and various practical applications. Duckweeds represent a group of tiny aquatic plants that include 36 species divided into 5 genera within the Lemnaceae family. They are an important part of aquatic ecosystems worldwide, often covering large portions of the water reservoirs they inhabit, and have many potential applications, including in bioremediation, biofuels, and biomanufacturing. Here, we evaluated the biodiversity of duckweeds in Ukraine and Eastern China by characterizing specimens using the two-barcode protocol with the chloroplast atpH–atpF and psbK–psbI spacer sequences. In total, 69 Chinese and Ukrainian duckweed specimens were sequenced. The sequences were compared against sequences in the NCBI database using BLAST. We identified six species from China (Spirodela polyrhiza, Landoltia punctata, Lemna aequinoctialis, Lemna minor, Lemna turionifera, and Wolffia globosa) and six from Ukraine (S. polyrhiza, Lemna gibba, Lemna minor, Lemna trisulca, Lemna turionifera, and Wolffia arrhiza). The most common duckweed species in the samples from Ukraine were Le. minor and S. polyrhiza, accounting for 17 and 15 out of 40 specimens, respectively. The most common duckweed species in the samples from China was S. polyrhiza, accounting for 15 out of 29 specimens. La. punctata and Le. aequinoctialis were also common in China, accounting for five and four specimens, respectively. According to both atpH–atpF and psbK–psbI barcode analyses, the species identified as Le. aequinoctialis does not form a uniform taxon similar to other duckweed species, and therefore the phylogenetic status of this species requires further clarification. By monitoring duckweeds using chloroplast DNA sequencing, we not only precisely identified local species and ecotypes, but also provided background for further exploration of native varieties with diverse genetic backgrounds. These data could be useful for future conservation, breeding, and biotechnological applications. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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12 pages, 1219 KiB  
Article
Effects of Partial Substitution of Conventional Protein Sources with Duckweed (Lemna minor) Meal in the Feeding of Rainbow Trout (Oncorhynchus mykiss) on Growth Performances and the Quality Product
by Elisa Fiordelmondo, Simona Ceschin, Gian Enrico Magi, Francesca Mariotti, Nicolaia Iaffaldano, Livio Galosi and Alessandra Roncarati
Plants 2022, 11(9), 1220; https://doi.org/10.3390/plants11091220 - 30 Apr 2022
Cited by 11 | Viewed by 2637
Abstract
Duckweed (Lemna minor) meal was included in the formulation of three experimental feeds (L1, L2, L3) for rainbow trout at 10%, 20%, 28% of the protein source, respectively. Increasing the duckweed inclusion, the other protein sources were adjusted to get isonitrogenous [...] Read more.
Duckweed (Lemna minor) meal was included in the formulation of three experimental feeds (L1, L2, L3) for rainbow trout at 10%, 20%, 28% of the protein source, respectively. Increasing the duckweed inclusion, the other protein sources were adjusted to get isonitrogenous (41%) and isolipidic (20%) diets, as the control diet (LC). 540 fish (mean body weight 124.5 ± 0.7 g) were randomly allocated in 12 tanks divided equally among the four different diets. After 90 days, fish were weighed and the most important productive performances, fillet quality and fatty acid profile were determined. The final body weight in L1 (340.53 g) and L2 (339.42 g) was not different from LC (348.80 g); L3 trout significantly (p < 0.05) exhibited the lowest one (302.16 g). Similar trends were found in final mean length, weight gain, specific growth rate, food conversion rate. Somatic indices were affected by duckweed inclusion. Diets had not significant effects on the proximate composition and fatty acids of the fillet in L1, L2, L3 respect to LC. Based on this study, duckweed meal derived from Lemna minor can be included in the feed for the rainbow trout without negative effects on the growth performances at 20% of the protein substitution. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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15 pages, 3652 KiB  
Article
Influence of Light Intensity and Spectrum on Duckweed Growth and Proteins in a Small-Scale, Re-Circulating Indoor Vertical Farm
by Finn Petersen, Johannes Demann, Dina Restemeyer, Hans-Werner Olfs, Heiner Westendarp, Klaus-Juergen Appenroth and Andreas Ulbrich
Plants 2022, 11(8), 1010; https://doi.org/10.3390/plants11081010 - 07 Apr 2022
Cited by 17 | Viewed by 4894
Abstract
Duckweeds can be potentially used in human and animal nutrition, biotechnology or wastewater treatment. To cultivate large quantities of a defined product quality, a standardized production process is needed. A small-scale, re-circulating indoor vertical farm (IVF) with artificial lighting and a nutrient control [...] Read more.
Duckweeds can be potentially used in human and animal nutrition, biotechnology or wastewater treatment. To cultivate large quantities of a defined product quality, a standardized production process is needed. A small-scale, re-circulating indoor vertical farm (IVF) with artificial lighting and a nutrient control and dosing system was used for this purpose. The influence of different light intensities (50, 100 and 150 µmol m−2 s−1) and spectral distributions (red/blue ratios: 70/30, 50/50 and 30/70%) on relative growth rate (RGR), crude protein content (CPC), relative protein yield (RPY) and chlorophyll a of the duckweed species Lemna minor and Wolffiella hyalina were investigated. Increasing light intensity increased RGR (by 67% and 76%) and RPY (by 50% and 89%) and decreased chlorophyll a (by 27% and 32%) for L. minor and W. hyalina, respectively. The spectral distributions had no significant impact on any investigated parameter. Wolffiella hyalina achieved higher values in all investigated parameters compared to L. minor. This investigation proved the successful cultivation of duckweed in a small-scale, re-circulating IVF with artificial lighting. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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11 pages, 1309 KiB  
Article
Intraspecific Diversity in Aquatic Ecosystems: Comparison between Spirodela polyrhiza and Lemna minor in Natural Populations of Duckweed
by Manuela Bog, Klaus-Juergen Appenroth, Philipp Schneider and K. Sowjanya Sree
Plants 2022, 11(7), 968; https://doi.org/10.3390/plants11070968 - 01 Apr 2022
Cited by 5 | Viewed by 2266
Abstract
Samples of two duckweed species, Spirodela polyrhiza and Lemna minor, were collected around small ponds and investigated concerning the question of whether natural populations of duckweeds constitute a single clone, or whether clonal diversity exists. Amplified fragment length polymorphism was used as [...] Read more.
Samples of two duckweed species, Spirodela polyrhiza and Lemna minor, were collected around small ponds and investigated concerning the question of whether natural populations of duckweeds constitute a single clone, or whether clonal diversity exists. Amplified fragment length polymorphism was used as a molecular method to distinguish clones of the same species. Possible intraspecific diversity was evaluated by average-linkage clustering. The main criterion to distinguish one clone from another was the 95% significance level of the Jaccard dissimilarity index for replicated samples. Within natural populations of L. minor, significant intraspecific genetic differences were detected. In each of the three small ponds harbouring populations of L. minor, based on twelve samples, between four and nine distinct clones were detected. Natural populations of L. minor consist of a mixture of several clones representing intraspecific biodiversity in an aquatic ecosystem. Moreover, identical distinct clones were discovered in more than one pond, located at a distance of 1 km and 2.4 km from each other. Evidently, fronds of L. minor were transported between these different ponds. The genetic differences for S. polyrhiza, however, were below the error-threshold of the method within a pond to detect distinct clones, but were pronounced between samples of two different ponds. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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15 pages, 4402 KiB  
Article
Auxin-Producing Bacteria from Duckweeds Have Different Colonization Patterns and Effects on Plant Morphology
by Sarah Gilbert, Alexander Poulev, William Chrisler, Kenneth Acosta, Galya Orr, Sarah Lebeis and Eric Lam
Plants 2022, 11(6), 721; https://doi.org/10.3390/plants11060721 - 08 Mar 2022
Cited by 13 | Viewed by 3858
Abstract
The role of auxin in plant–microbe interaction has primarily been studied using indole-3-acetic acid (IAA)-producing pathogenic or plant-growth-promoting bacteria. However, the IAA biosynthesis pathway in bacteria involves indole-related compounds (IRCs) and intermediates with less known functions. Here, we seek to understand changes in [...] Read more.
The role of auxin in plant–microbe interaction has primarily been studied using indole-3-acetic acid (IAA)-producing pathogenic or plant-growth-promoting bacteria. However, the IAA biosynthesis pathway in bacteria involves indole-related compounds (IRCs) and intermediates with less known functions. Here, we seek to understand changes in plant response to multiple plant-associated bacteria taxa and strains that differ in their ability to produce IRCs. We had previously studied 47 bacterial strains isolated from several duckweed species and determined that 79% of these strains produced IRCs in culture, such as IAA, indole lactic acid (ILA), and indole. Using Arabidopsis thaliana as our model plant with excellent genetic tools, we performed binary association assays on a subset of these strains to evaluate morphological responses in the plant host and the mode of bacterial colonization. Of the 21 tested strains, only four high-quantity IAA-producing Microbacterium strains caused an auxin root phenotype. Compared to the commonly used colorimetric Salkowski assay, auxin concentration determined by LC–MS was a superior indicator of a bacteria’s ability to cause an auxin root phenotype. Studies with the auxin response mutant axr1-3 provided further genetic support for the role of auxin signaling in mediating the root morphology response to IAA-producing bacteria strains. Interestingly, our microscopy results also revealed new evidence for the role of the conserved AXR1 gene in endophytic colonization of IAA-producing Azospirillum baldaniorum Sp245 via the guard cells. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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20 pages, 2608 KiB  
Article
The Dynamics of NO3 and NH4+ Uptake in Duckweed Are Coordinated with the Expression of Major Nitrogen Assimilation Genes
by Yuzhen Zhou, Olena Kishchenko, Anton Stepanenko, Guimin Chen, Wei Wang, Jie Zhou, Chaozhi Pan and Nikolai Borisjuk
Plants 2022, 11(1), 11; https://doi.org/10.3390/plants11010011 - 21 Dec 2021
Cited by 19 | Viewed by 3895
Abstract
Duckweed plants play important roles in aquatic ecosystems worldwide. They rapidly accumulate biomass and have potential uses in bioremediation of water polluted by fertilizer runoff or other chemicals. Here we studied the assimilation of two major sources of inorganic nitrogen, nitrate ( [...] Read more.
Duckweed plants play important roles in aquatic ecosystems worldwide. They rapidly accumulate biomass and have potential uses in bioremediation of water polluted by fertilizer runoff or other chemicals. Here we studied the assimilation of two major sources of inorganic nitrogen, nitrate (NO3 ) and ammonium (NH4+), in six duckweed species: Spirodela polyrhiza, Landoltia punctata, Lemna aequinoctialis, Lemna turionifera, Lemna minor, and Wolffia globosa. All six duckweed species preferred NH4+ over NO3 and started using NO3 only when NH4+ was depleted. Using the available genome sequence, we analyzed the molecular structure and expression of eight key nitrogen assimilation genes in S. polyrhiza. The expression of genes encoding nitrate reductase and nitrite reductase increased about 10-fold when NO3 was supplied and decreased when NH4+ was supplied. NO3 and NH4+ induced the glutamine synthetase (GS) genes GS1;2 and the GS2 by 2- to 5-fold, respectively, but repressed GS1;1 and GS1;3. NH4+ and NO3 upregulated the genes encoding ferredoxin- and NADH-dependent glutamate synthases (Fd-GOGAT and NADH-GOGAT). A survey of nitrogen assimilation gene promoters suggested complex regulation, with major roles for NRE-like and GAATC/GATTC cis-elements, TATA-based enhancers, GA/CTn repeats, and G-quadruplex structures. These results will inform efforts to improve bioremediation and nitrogen use efficiency. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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20 pages, 3052 KiB  
Article
New Insights into Interspecific Hybridization in Lemna L. Sect. Lemna (Lemnaceae Martinov)
by Luca Braglia, Diego Breviario, Silvia Gianì, Floriana Gavazzi, Jacopo De Gregori and Laura Morello
Plants 2021, 10(12), 2767; https://doi.org/10.3390/plants10122767 - 15 Dec 2021
Cited by 17 | Viewed by 3094
Abstract
Duckweeds have been increasingly studied in recent years, both as model plants and in view of their potential applications as a new crop in a circular bioeconomy perspective. In order to select species and clones with the desired attributes, the correct identification of [...] Read more.
Duckweeds have been increasingly studied in recent years, both as model plants and in view of their potential applications as a new crop in a circular bioeconomy perspective. In order to select species and clones with the desired attributes, the correct identification of the species is fundamental. Molecular methods have recently provided a more solid base for taxonomy and yielded a consensus phylogenetic tree, although some points remain to be elucidated. The duckweed genus Lemna L. comprises twelve species, grouped in four sections, which include very similar sister species. The least taxonomically resolved is sect. Lemna, presenting difficulties in species delimitation using morphological and even barcoding molecular markers. Ambiguous species boundaries between Lemna minor L. and Lemna japonica Landolt have been clarified by Tubulin Based Polymorphism (TBP), with the discovery of interspecific hybrids. In the present work, we extended TBP profiling to a larger number of clones in sect. Lemna, previously classified using only morphological features, in order to test that classification, and to investigate the possible existence of other hybrids in this section. The analysis revealed several misidentifications of clones, in particular among the species L. minor, L. japonica and Lemna gibba L., and identified six putative ‘L. gibba’ clones as interspecific hybrids between L. minor and L. gibba. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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19 pages, 6944 KiB  
Article
Chlorophyll Fluorescence Imaging-Based Duckweed Phenotyping to Assess Acute Phytotoxic Effects
by Viktor Oláh, Anna Hepp, Muhammad Irfan and Ilona Mészáros
Plants 2021, 10(12), 2763; https://doi.org/10.3390/plants10122763 - 14 Dec 2021
Cited by 24 | Viewed by 3445
Abstract
Duckweeds (Lemnaceae species) are extensively used models in ecotoxicology, and chlorophyll fluorescence imaging offers a sensitive and high throughput platform for phytotoxicity assays with these tiny plants. However, the vast number of potentially applicable chlorophyll fluorescence-based test endpoints makes comparison and generalization of [...] Read more.
Duckweeds (Lemnaceae species) are extensively used models in ecotoxicology, and chlorophyll fluorescence imaging offers a sensitive and high throughput platform for phytotoxicity assays with these tiny plants. However, the vast number of potentially applicable chlorophyll fluorescence-based test endpoints makes comparison and generalization of results hard among different studies. The present study aimed to jointly measure and compare the sensitivity of various chlorophyll fluorescence parameters in Spirodela polyrhiza (giant duckweed) plants exposed to nickel, chromate (hexavalent chromium) and sodium chloride for 72 h, respectively. The photochemistry of Photosystem II in both dark- and light-adapted states of plants was assessed via in vivo chlorophyll fluorescence imaging method. Our results indicated that the studied parameters responded with very divergent sensitivity, highlighting the importance of parallelly assessing several chlorophyll fluorescence parameters. Generally, the light-adapted parameters were more sensitive than the dark-adapted ones. Thus, the former ones might be the preferred endpoints in phytotoxicity assays. Fv/Fm, i.e., the most extensively reported parameter literature-wise, proved to be the least sensitive endpoint; therefore, future studies might also consider reporting Fv/Fo, as its more responsive analogue. The tested toxicants induced different trends in the basic chlorophyll fluorescence parameters and, at least partly, in relative proportions of different quenching processes, suggesting that a basic distinction of water pollutants with different modes of action might be achievable by this method. We found definite hormetic patterns in responses to several endpoints. Hormesis occurred in the concentration ranges where the applied toxicants resulted in strong growth inhibition in longer-term exposures of the same duckweed clone in previous studies. These findings indicate that changes in the photochemical efficiency of plants do not necessarily go hand in hand with growth responses, and care should be taken when one exclusively interprets chlorophyll fluorescence-based endpoints as general proxies for phytotoxic effects. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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13 pages, 1592 KiB  
Article
Influence of the Nitrate-N to Ammonium-N Ratio on Relative Growth Rate and Crude Protein Content in the Duckweeds Lemna minor and Wolffiella hyalina
by Finn Petersen, Johannes Demann, Dina Restemeyer, Andreas Ulbrich, Hans-Werner Olfs, Heiner Westendarp and Klaus-Jürgen Appenroth
Plants 2021, 10(8), 1741; https://doi.org/10.3390/plants10081741 - 23 Aug 2021
Cited by 18 | Viewed by 4390
Abstract
In order to produce protein-rich duckweed for human and animal consumption, a stable cultivation process, including an optimal nutrient supply for each species, must be implemented. Modified nutrient media, based on the N-medium for duckweed cultivation, were tested on the relative growth rate [...] Read more.
In order to produce protein-rich duckweed for human and animal consumption, a stable cultivation process, including an optimal nutrient supply for each species, must be implemented. Modified nutrient media, based on the N-medium for duckweed cultivation, were tested on the relative growth rate (RGR) and crude protein content (CPC) of Lemna minor and Wolffiella hyalina, as well as the decrease of nitrate-N and ammonium-N in the media. Five different nitrate-N to ammonium-N molar ratios were diluted to 10% and 50% of the original N-medium concentration. The media mainly consisted of agricultural fertilizers. A ratio of 75% nitrate-N and 25% ammonium-N, with a dilution of 50%, yielded the best results for both species. Based on the dry weight (DW), L. minor achieved a RGR of 0.23 ± 0.009 d−1 and a CPC of 37.8 ± 0.42%, while W. hyalina’s maximum RGR was 0.22 ± 0.017 d−1, with a CPC of 43.9 ± 0.34%. The relative protein yield per week and m2 was highest at this ratio and dilution, as well as the ammonium-N decrease in the corresponding medium. These results could be implemented in duckweed research and applications if a high protein content or protein yield is the aim. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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17 pages, 2254 KiB  
Article
Density Dependence Influences the Efficacy of Wastewater Remediation by Lemna minor
by Éamonn Walsh, Neil E. Coughlan, Seán O’Brien, Marcel A. K. Jansen and Holger Kuehnhold
Plants 2021, 10(7), 1366; https://doi.org/10.3390/plants10071366 - 03 Jul 2021
Cited by 13 | Viewed by 3177
Abstract
As part of a circular economy (CE) approach to food production systems, Lemnaceae, i.e., duckweed species, can be used to remediate wastewater due to rapid nutrient assimilation and tolerance of non-optimal growing conditions. Further, given rapid growth rates and high protein content, [...] Read more.
As part of a circular economy (CE) approach to food production systems, Lemnaceae, i.e., duckweed species, can be used to remediate wastewater due to rapid nutrient assimilation and tolerance of non-optimal growing conditions. Further, given rapid growth rates and high protein content, duckweed species are a valuable biomass. An important consideration for duckweed-mediated remediation is the density at which the plants grow on the surface of the wastewater, i.e., how much of the surface of the medium they cover. Higher duckweed density is known to have a negative effect on duckweed growth, which has implications for the development of duckweed-based remediation systems. In the present study, the effects of density (10–80% plant surface coverage) on Lemna minor growth, chlorophyll fluorescence and nutrient remediation of synthetic dairy processing wastewater were assessed in stationary (100 mL) and re-circulating non-axenic (11.7 L) remediation systems. Overall, L. minor growth, and TN and TP removal rates decreased as density increased. However, in the stationary system, absolute TN and TP removal were greater at higher densities (50–80% coverage). The exact cause of density related growth reduction in duckweed is unclear, especially at densities well below 100% surface coverage. A further experiment comparing duckweed grown at ‘low’ and ‘high’ density conditions with the same biomass and media volume conditions, showed that photosynthetic yield, Y(II), is reduced at high density despite the same nutrient availability at both densities, and arguably similar shading. The results demonstrate a negative effect of high density on duckweed growth and nutrient uptake, and point towards signals from neighbouring duckweed colonies as the possible cause. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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17 pages, 1303 KiB  
Article
Brassinolide Enhances the Level of Brassinosteroids, Protein, Pigments, and Monosaccharides in Wolffia arrhiza Treated with Brassinazole
by Magdalena Chmur and Andrzej Bajguz
Plants 2021, 10(7), 1311; https://doi.org/10.3390/plants10071311 - 28 Jun 2021
Cited by 11 | Viewed by 2827
Abstract
Brassinolide (BL) represents brassinosteroids (BRs)—a group of phytohormones that are essential for plant growth and development. Brassinazole (Brz) is as a synthetic inhibitor of BRs’ biosynthesis. In the present study, the responses of Wolffia arrhiza to the treatment with BL, Brz, and the [...] Read more.
Brassinolide (BL) represents brassinosteroids (BRs)—a group of phytohormones that are essential for plant growth and development. Brassinazole (Brz) is as a synthetic inhibitor of BRs’ biosynthesis. In the present study, the responses of Wolffia arrhiza to the treatment with BL, Brz, and the combination of BL with Brz were analyzed. The analysis of BRs and Brz was performed using LC-MS/MS. The photosynthetic pigments (chlorophylls, carotenes, and xanthophylls) levels were determined using HPLC, but protein and monosaccharides level using spectrophotometric methods. The obtained results indicated that BL and Brz influence W. arrhiza cultures in a concentration-dependent manner. The most stimulatory effects on the growth, level of BRs (BL, 24-epibrassinolide, 28-homobrassinolide, 28-norbrassinolide, catasterone, castasterone, 24-epicastasterone, typhasterol, and 6-deoxytyphasterol), and the content of pigments, protein, and monosaccharides, were observed in plants treated with 0.1 µM BL. Whereas the application of 1 µM and 10 µM Brz caused a significant decrease in duckweed weight and level of targeted compounds. Application of BL caused the mitigation of the Brz inhibitory effect and enhanced the BR level in duckweed treated with Brz. The level of BRs was reported for the first time in duckweed treated with BL and/or Brz. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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17 pages, 1932 KiB  
Article
Lemna minor Cultivation for Treating Swine Manure and Providing Micronutrients for Animal Feed
by Reindert Devlamynck, Marcella Fernandes de Souza, Jan Leenknegt, Liesbeth Jacxsens, Mia Eeckhout and Erik Meers
Plants 2021, 10(6), 1124; https://doi.org/10.3390/plants10061124 - 01 Jun 2021
Cited by 10 | Viewed by 3863
Abstract
The potential of Lemna minor to valorise agricultural wastewater into a protein-rich feed component to meet the growing demand for animal feed protein and reduce the excess of nutrients in certain European regions was investigated. Three pilot-scale systems were monitored for nine weeks [...] Read more.
The potential of Lemna minor to valorise agricultural wastewater into a protein-rich feed component to meet the growing demand for animal feed protein and reduce the excess of nutrients in certain European regions was investigated. Three pilot-scale systems were monitored for nine weeks under outdoor conditions in Flanders. The systems were fed with a mixture of the liquid fraction and the biological effluent of a swine manure treatment system diluted with rainwater in order that the weekly N and P addition was equal to the N and P removal by the system. The design tested the accumulation of elements in a continuous recirculation system. Potassium, Cl, S, Ca, and Mg were abundantly available in the swine manure wastewaters and tended to accumulate, being a possible cause of concern for long-operating recirculation systems. The harvested duckweed was characterised for its mineral composition and protein content. In animal husbandry, trace elements are specifically added to animal feed as micronutrients and, thus, feedstuffs biofortified with essential trace elements can provide added value. Duckweed grown on the tested mixture of swine manure waste streams could be considered as a source of Mn, Zn, and Fe for swine feed, while it is not a source of Cu for swine feed. Moreover, it was observed that As, Cd, and Pb content were below the limits of the feed Directive 2002/32/EC in the duckweed grown on the tested medium. Overall, these results demonstrate that duckweed can effectively remove nutrients from agriculture wastewaters in a recirculated system while producing a feed source with a protein content of 35% DM. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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Review

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30 pages, 1363 KiB  
Review
Survival Strategies of Duckweeds, the World’s Smallest Angiosperms
by Paul Ziegler, Klaus J. Appenroth and K. Sowjanya Sree
Plants 2023, 12(11), 2215; https://doi.org/10.3390/plants12112215 - 03 Jun 2023
Cited by 7 | Viewed by 2973
Abstract
Duckweeds (Lemnaceae) are small, simply constructed aquatic higher plants that grow on or just below the surface of quiet waters. They consist primarily of leaf-like assimilatory organs, or fronds, that reproduce mainly by vegetative replication. Despite their diminutive size and inornate habit, duckweeds [...] Read more.
Duckweeds (Lemnaceae) are small, simply constructed aquatic higher plants that grow on or just below the surface of quiet waters. They consist primarily of leaf-like assimilatory organs, or fronds, that reproduce mainly by vegetative replication. Despite their diminutive size and inornate habit, duckweeds have been able to colonize and maintain themselves in almost all of the world’s climate zones. They are thereby subject to multiple adverse influences during the growing season, such as high temperatures, extremes of light intensity and pH, nutrient shortage, damage by microorganisms and herbivores, the presence of harmful substances in the water, and competition from other aquatic plants, and they must also be able to withstand winter cold and drought that can be lethal to the fronds. This review discusses the means by which duckweeds come to grips with these adverse influences to ensure their survival. Important duckweed attributes in this regard are a pronounced potential for rapid growth and frond replication, a juvenile developmental status facilitating adventitious organ formation, and clonal diversity. Duckweeds have specific features at their disposal for coping with particular environmental difficulties and can also cooperate with other organisms of their surroundings to improve their survival chances. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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19 pages, 1102 KiB  
Review
Duckweeds for Phytoremediation of Polluted Water
by Yuzhen Zhou, Anton Stepanenko, Olena Kishchenko, Jianming Xu and Nikolai Borisjuk
Plants 2023, 12(3), 589; https://doi.org/10.3390/plants12030589 - 29 Jan 2023
Cited by 16 | Viewed by 7583
Abstract
Tiny aquatic plants from the Lemnaceae family, commonly known as duckweeds, are often regarded as detrimental to the environment because of their ability to quickly populate and cover the surfaces of bodies of water. Due to their rapid vegetative propagation, duckweeds have one [...] Read more.
Tiny aquatic plants from the Lemnaceae family, commonly known as duckweeds, are often regarded as detrimental to the environment because of their ability to quickly populate and cover the surfaces of bodies of water. Due to their rapid vegetative propagation, duckweeds have one of the fastest growth rates among flowering plants and can accumulate large amounts of biomass in relatively short time periods. Due to the high yield of valuable biomass and ease of harvest, duckweeds can be used as feedstock for biofuels, animal feed, and other applications. Thanks to their efficient absorption of nitrogen- and phosphate-containing pollutants, duckweeds play an important role in the restorative ecology of water reservoirs. Moreover, compared to other species, duckweed species and ecotypes demonstrate exceptionally high adaptivity to a variety of environmental factors; indeed, duckweeds remove and convert many contaminants, such as nitrogen, into plant biomass. The global distribution of duckweeds and their tolerance of ammonia, heavy metals, other pollutants, and stresses are the major factors highlighting their potential for use in purifying agricultural, municipal, and some industrial wastewater. In summary, duckweeds are a powerful tool for bioremediation that can reduce anthropogenic pollution in aquatic ecosystems and prevent water eutrophication in a simple, inexpensive ecologically friendly way. Here we review the potential for using duckweeds in phytoremediation of several major water pollutants: mineral nitrogen and phosphorus, various organic chemicals, and heavy metals. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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23 pages, 4127 KiB  
Review
Growth and Nutritional Quality of Lemnaceae Viewed Comparatively in an Ecological and Evolutionary Context
by Barbara Demmig-Adams, Marina López-Pozo, Stephanie K. Polutchko, Paul Fourounjian, Jared J. Stewart, Madeleine C. Zenir and William W. Adams III
Plants 2022, 11(2), 145; https://doi.org/10.3390/plants11020145 - 06 Jan 2022
Cited by 12 | Viewed by 2692
Abstract
This review focuses on recently characterized traits of the aquatic floating plant Lemna with an emphasis on its capacity to combine rapid growth with the accumulation of high levels of the essential human micronutrient zeaxanthin due to an unusual pigment composition not seen [...] Read more.
This review focuses on recently characterized traits of the aquatic floating plant Lemna with an emphasis on its capacity to combine rapid growth with the accumulation of high levels of the essential human micronutrient zeaxanthin due to an unusual pigment composition not seen in other fast-growing plants. In addition, Lemna’s response to elevated CO2 was evaluated in the context of the source–sink balance between plant sugar production and consumption. These and other traits of Lemnaceae are compared with those of other floating aquatic plants as well as terrestrial plants adapted to different environments. It was concluded that the unique features of aquatic plants reflect adaptations to the freshwater environment, including rapid growth, high productivity, and exceptionally strong accumulation of high-quality vegetative storage protein and human antioxidant micronutrients. It was further concluded that the insensitivity of growth rate to environmental conditions and plant source–sink imbalance may allow duckweeds to take advantage of elevated atmospheric CO2 levels via particularly strong stimulation of biomass production and only minor declines in the growth of new tissue. It is proposed that declines in nutritional quality under elevated CO2 (due to regulatory adjustments in photosynthetic metabolism) may be mitigated by plant–microbe interaction, for which duckweeds have a high propensity. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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20 pages, 5880 KiB  
Review
Lemnaceae and Orontiaceae Are Phylogenetically and Morphologically Distinct from Araceae
by Nicholas P. Tippery, Donald H. Les, Klaus J. Appenroth, K. Sowjanya Sree, Daniel J. Crawford and Manuela Bog
Plants 2021, 10(12), 2639; https://doi.org/10.3390/plants10122639 - 30 Nov 2021
Cited by 16 | Viewed by 3335
Abstract
Duckweeds comprise a distinctive clade of pleustophytic monocots that traditionally has been classified as the family Lemnaceae. However, molecular evidence has called into question their phylogenetic independence, with some authors asserting instead that duckweeds should be reclassified as subfamily Lemnoideae of an expanded [...] Read more.
Duckweeds comprise a distinctive clade of pleustophytic monocots that traditionally has been classified as the family Lemnaceae. However, molecular evidence has called into question their phylogenetic independence, with some authors asserting instead that duckweeds should be reclassified as subfamily Lemnoideae of an expanded family Araceae. Although a close phylogenetic relationship of duckweeds with traditional Araceae has been supported by multiple studies, the taxonomic disposition of duckweeds must be evaluated more critically to promote nomenclatural stability and utility. Subsuming duckweeds as a morphologically incongruent lineage of Araceae effectively eliminates the family category of Lemnaceae that has been widely used for many years. Instead, we suggest that Araceae subfamily Orontioideae should be restored to family status as Orontiaceae, which thereby would enable the recognition of three morphologically and phylogenetically distinct lineages: Araceae, Lemnaceae, and Orontiaceae. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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11 pages, 1199 KiB  
Review
The World Smallest Plants (Wolffia Sp.) as Potential Species for Bioregenerative Life Support Systems in Space
by Leone Ermes Romano and Giovanna Aronne
Plants 2021, 10(9), 1896; https://doi.org/10.3390/plants10091896 - 13 Sep 2021
Cited by 8 | Viewed by 6856
Abstract
To colonise other planets, self-sufficiency of space missions is mandatory. To date, the most promising technology to support long-duration missions is the bioregenerative life support system (BLSS), in which plants as autotrophs play a crucial role in recycling wastes and producing food and [...] Read more.
To colonise other planets, self-sufficiency of space missions is mandatory. To date, the most promising technology to support long-duration missions is the bioregenerative life support system (BLSS), in which plants as autotrophs play a crucial role in recycling wastes and producing food and oxygen. We reviewed the scientific literature on duckweed (Lemnaceae) and reported available information on plant biological traits, nutritional features, biomass production, and space applications, especially of the genus Wolffia. Results confirmed that the smallest existing higher plants are the best candidate for space BLSS. We discussed needs for further research before criticalities to be addressed to finalise the adoption of Wolffia species for space missions. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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9 pages, 3041 KiB  
Conference Report
Sustainable Stress Management: Aquatic Plants vs. Terrestrial Plants
by K. Sowjanya Sree, Klaus J. Appenroth and Ralf Oelmüller
Plants 2023, 12(11), 2208; https://doi.org/10.3390/plants12112208 - 03 Jun 2023
Cited by 1 | Viewed by 1013
Abstract
The Indo-German Science and Technology Centre (IGSTC) funded an Indo-German Workshop on Sustainable Stress Management: Aquatic plants vs. Terrestrial plants (IGW-SSMAT) which was jointly organized at the Friedrich Schiller University of Jena, Germany from 25 to 27 July 2022 by Prof. [...] Read more.
The Indo-German Science and Technology Centre (IGSTC) funded an Indo-German Workshop on Sustainable Stress Management: Aquatic plants vs. Terrestrial plants (IGW-SSMAT) which was jointly organized at the Friedrich Schiller University of Jena, Germany from 25 to 27 July 2022 by Prof. Dr. Ralf Oelmüller, Friedrich Schiller University of Jena, Germany as the German coordinator and Dr. K. Sowjanya Sree, Central University of Kerala, India as the Indian Coordinator. The workshop constituted researchers working in this field from both India and Germany and brought together these experts in the field of sustainable stress management for scientific discussions, brainstorming and networking. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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12 pages, 2392 KiB  
Conference Report
Sixth International Conference on Duckweed Research and Applications Presents Lemnaceae as a Model Plant System in the Genomics and Postgenomics Era
by Viktor Oláh, Klaus-Juergen Appenroth, Eric Lam and K. Sowjanya Sree
Plants 2023, 12(11), 2134; https://doi.org/10.3390/plants12112134 - 28 May 2023
Cited by 1 | Viewed by 2182
Abstract
The 6th International Conference on Duckweed Research and Applications (6th ICDRA) was organized at the Institute of Plant Genetics and Crop Plant Research (IPK) located in Gatersleben, Germany, from 29 May to 1 June 2022. The growing community of duckweed research and application [...] Read more.
The 6th International Conference on Duckweed Research and Applications (6th ICDRA) was organized at the Institute of Plant Genetics and Crop Plant Research (IPK) located in Gatersleben, Germany, from 29 May to 1 June 2022. The growing community of duckweed research and application specialists was noted with participants from 21 different countries including an increased share of newly integrated young researchers. The four-day conference focused on diverse aspects of basic and applied research together with practical applications of these tiny aquatic plants that could have an enormous potential for biomass production. Full article
(This article belongs to the Special Issue Duckweed: Research Meets Applications)
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