Plants

13 pages, 768 KiB

Open AccessArticle

Utilization of in Vitro Anther Culture in Spelt Wheat Breeding

by Csaba Lantos, Szandra Purgel, Katalin Ács, Bernadett Langó, Lajos Bóna, Krisztina Boda, Ferenc Békés and János Pauk

Plants 2019, 8(10), 436; https://doi.org/10.3390/plants8100436 - 22 Oct 2019

Cited by 14 | Viewed by 5422

Abstract

The efficiency of in vitro anther culture was screened in a full diallel population of four spelt wheat genotypes and ten F₁ hybrids. Genotype dependency was observed based on the data of embryo-like structures (ELS), green-, albino plantlets. In the diallel population [...] Read more.

The efficiency of in vitro anther culture was screened in a full diallel population of four spelt wheat genotypes and ten F₁ hybrids. Genotype dependency was observed based on the data of embryo-like structures (ELS), green-, albino plantlets. In the diallel population and ten F₁ hybrids, the green plantlets production ranged from 13.75 to 85.00 and from 6.30 to 51.00, respectively. The anther culture-derived plants of F₁ hybrids were grown up in the nursery. At the harvest, 436 spontaneous doubled haploid (DH) plants were identified among the 1535 anther culture-derived transplanted and grown up individual plants. The mean of spontaneous rediploidization was 28.4% which ranged from 9.76% to 54.24%. In two consecutive years, the agronomic values of ‘Tonkoly.pop1’ advanced line were compared with seven DH lines of ‘Tonkoly.pop1’ in the nursery. The DH lines achieved competitive values in comparison with ‘Tonkoly.pop1’ advanced line based on the 11 measured parameters (heading date, plant height, yield, hardness, width and length of seed, TKW, hulling yield, flour yield, protein and wet gluten content). These observations presage the efficient utilization of anther culture in spelt wheat breeding. Full article

(This article belongs to the Collection Doubled Haploid Technology in Plant Breeding)

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16 pages, 888 KiB

Open AccessEditor’s ChoiceReview

Potassium in Root Growth and Development

by Marek Sustr, Ales Soukup and Edita Tylova

Plants 2019, 8(10), 435; https://doi.org/10.3390/plants8100435 - 22 Oct 2019

Cited by 115 | Viewed by 11421

Abstract

Potassium is an essential macronutrient that has been partly overshadowed in root science by nitrogen and phosphorus. The current boom in potassium-related studies coincides with an emerging awareness of its importance in plant growth, metabolic functions, stress tolerance, and efficient agriculture. In this [...] Read more.

Potassium is an essential macronutrient that has been partly overshadowed in root science by nitrogen and phosphorus. The current boom in potassium-related studies coincides with an emerging awareness of its importance in plant growth, metabolic functions, stress tolerance, and efficient agriculture. In this review, we summarized recent progress in understanding the role of K⁺ in root growth, development of root system architecture, cellular functions, and specific plant responses to K⁺ shortage. K⁺ transport is crucial for its physiological role. A wide range of K⁺ transport proteins has developed during evolution and acquired specific functions in plants. There is evidence linking K⁺ transport with cell expansion, membrane trafficking, auxin homeostasis, cell signaling, and phloem transport. This places K⁺ among important general regulatory factors of root growth. K⁺ is a rather mobile element in soil, so the absence of systemic and localized root growth response has been accepted. However, recent research confirms both systemic and localized growth response in Arabidopsis thaliana and highlights K⁺ uptake as a crucial mechanism for plant stress response. K⁺-related regulatory mechanisms, K⁺ transporters, K⁺ acquisition efficiency, and phenotyping for selection of K⁺ efficient plants/cultivars are highlighted in this review. Full article

(This article belongs to the Special Issue Root System Structure and Function: A Themed Issue in Honor of Professor Yoav Waisel)

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14 pages, 774 KiB

Open AccessArticle

Effect of Freezing on Photosystem II and Assessment of Freezing Tolerance of Tea Cultivar

by Yun-Long Shi, Zhuo-Yu Cai, Da Li, Jian-Liang Lu, Jian-Hui Ye, Yue-Rong Liang and Xin-Qiang Zheng

Plants 2019, 8(10), 434; https://doi.org/10.3390/plants8100434 - 22 Oct 2019

Cited by 11 | Viewed by 5895

Abstract

Freezing tolerant tea cultivars are urgently needed. The tea cultivars with highly freezing tolerance showed resistance to freezing stress induced photoinhibition. Freezing sensitivity index (H) of 47 tea clonal cultivars was investigated after severe freezing winter in 2016. To develop instrumental methods for [...] Read more.

Freezing tolerant tea cultivars are urgently needed. The tea cultivars with highly freezing tolerance showed resistance to freezing stress induced photoinhibition. Freezing sensitivity index (H) of 47 tea clonal cultivars was investigated after severe freezing winter in 2016. To develop instrumental methods for freezing tolerance selection, the maximum photochemical efficiency of photosystem II (PSII) (Fv/Fm) and leaf color indicator a on the Hunter color scale were determined on control group (non-frozen) and frozen group (being frozen at −15 °C for 2 h and then stood at 20 °C for 5 h) of the cultivars. When the two indicators were expressed as the ratios (R_Fv/Fm and R_a) of frozen group to control group, linear regression of the freezing sensitivity index (H) upon the R_Fv/Fm and R_a produced significant relationship respectively, i.e., H = 60.31 − 50.09 R_Fv/Fm (p < 0.01) and H = 30.03 − 10.82 R_a (p < 0.01). Expression of gene psbA encoding D1 protein and gene psbD encoding D2 protein in PSII showed that the frezzing tolerant tea cultivars maintained a high expression level of psbA after freezing stress, which is considered to be beneficial to de novo synthesis of D1 protein and sustaining PSII activity. These findings can provide instrumental tools for assessing freezing tolerance of tea cultivars in tea breeding program. Full article

(This article belongs to the Special Issue Plant and Microbe Adaptations to Cold)

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19 pages, 1857 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Coordination of Leaf Development Across Developmental Axes

by James W. Satterlee and Michael J. Scanlon

Plants 2019, 8(10), 433; https://doi.org/10.3390/plants8100433 - 22 Oct 2019

Cited by 21 | Viewed by 10046

Abstract

Leaves are initiated as lateral outgrowths from shoot apical meristems throughout the vegetative life of the plant. To achieve proper developmental patterning, cell-type specification and growth must occur in an organized fashion along the proximodistal (base-to-tip), mediolateral (central-to-edge), and adaxial–abaxial (top-bottom) axes of [...] Read more.

Leaves are initiated as lateral outgrowths from shoot apical meristems throughout the vegetative life of the plant. To achieve proper developmental patterning, cell-type specification and growth must occur in an organized fashion along the proximodistal (base-to-tip), mediolateral (central-to-edge), and adaxial–abaxial (top-bottom) axes of the developing leaf. Early studies of mutants with defects in patterning along multiple leaf axes suggested that patterning must be coordinated across developmental axes. Decades later, we now recognize that a highly complex and interconnected transcriptional network of patterning genes and hormones underlies leaf development. Here, we review the molecular genetic mechanisms by which leaf development is coordinated across leaf axes. Such coordination likely plays an important role in ensuring the reproducible phenotypic outcomes of leaf morphogenesis. Full article

(This article belongs to the Special Issue From Genes to Shape and Function: Leaf Morphogenesis at Play)

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10 pages, 2091 KiB

Open AccessArticle

Genome-Wide Association Analysis of Plant Height Using the Maize F1 Population

by Yong Zhang, Jiyu Wan, Lian He, Hai Lan and Lujiang Li

Plants 2019, 8(10), 432; https://doi.org/10.3390/plants8100432 - 21 Oct 2019

Cited by 14 | Viewed by 3800

Abstract

Drastic changes in plant height (PH) are observed when maize adapt to a higher plant density. Most importantly, PH is an important factor affecting maize yield. Although the genetic basis of PH has been extensively studied using different populations during the past decades, [...] Read more.

Drastic changes in plant height (PH) are observed when maize adapt to a higher plant density. Most importantly, PH is an important factor affecting maize yield. Although the genetic basis of PH has been extensively studied using different populations during the past decades, genetic basis remains unclear in the F1 population, which was a widely used population in production. In this study, a genome-wide association study (GWAS) was conducted using an F1 population consisting of 300 maize hybrids with 17,652 single nucleotide polymorphisms (SNPs) makers to identify candidate genes for controlling PH. A total of nine significant SNPs makers and two candidate genes were identified for PH. The candidate genes, Zm00001d018617 and Zm00001d023659, were the genes most probable to be involved in the development of PH. Our results provide new insights into the genetic basis of PH in maize. Full article

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14 pages, 1713 KiB

Open AccessArticle

Silicon Priming Regulates Morpho-Physiological Growth and Oxidative Metabolism in Maize under Drought Stress

by Abida Parveen, Wei Liu, Saddam Hussain, Jaleel Asghar, Shagufta Perveen and Yousheng Xiong

Plants 2019, 8(10), 431; https://doi.org/10.3390/plants8100431 - 20 Oct 2019

Cited by 115 | Viewed by 6336

Abstract

Seed priming with silicon (Si) is an efficient and easy method to regulate plant tolerance against different abiotic stresses. A pot experiment was conducted to examine the Si-mediated changes in oxidative defense and some vital physio-biochemical parameters of maize under a limited water [...] Read more.

Seed priming with silicon (Si) is an efficient and easy method to regulate plant tolerance against different abiotic stresses. A pot experiment was conducted to examine the Si-mediated changes in oxidative defense and some vital physio-biochemical parameters of maize under a limited water supply. For this purpose, two maize varieties (Pearl and Malka) with different Si priming treatments (0, 4 mM, 6 mM) were grown under a control and 60% field capacity for three weeks. At 60% field capacity, significant reductions in plant growth attributes and chlorophyll contents were recorded compared with the control. The negative effects of drought stress were more severe for Malka compared with Pearl. Drought stress increased the malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents, altered the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), and triggered the accumulation of soluble sugars, glycine betaine, proline, and phenolics contents. Nevertheless, seed priming with silicon at 4 or 6 mM was effective in alleviating the detrimental effects of drought stress in both cultivars. Si priming particularly at 6 mM significantly enhanced the shoot and root lengths as well as their biomass and improved the levels of photosynthetic pigments. Moreover, Si treatments enhanced the activities of antioxidant enzymes (SOD, POD, and CAT) while it reduced the MDA and H₂O₂ contents in both cultivars under stress conditions. In crux, the present investigation suggests that Si priming mitigates the harmful effects of drought stress and contributes to the recovery of maize growth. Full article

(This article belongs to the Special Issue Plant Responses to Water-Deficit Stress)

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18 pages, 3003 KiB

Open AccessArticle

Improved Production of Industrially Important Essential Oils Through Elicitation in the Adventitious Roots of Artemisia amygdalina

by Faqeer Taj, Mubarak Ali Khan, Huma Ali and Raham Sher Khan

Plants 2019, 8(10), 430; https://doi.org/10.3390/plants8100430 - 20 Oct 2019

Cited by 12 | Viewed by 3643

Abstract

The limited production of bioactive essential oils in natural plants does not meet the increasing worldwide market demand. Plant cell culture technology can be used for the higher production of industrially important essential oils. In the present study, a suitable method for production [...] Read more.

The limited production of bioactive essential oils in natural plants does not meet the increasing worldwide market demand. Plant cell culture technology can be used for the higher production of industrially important essential oils. In the present study, a suitable method for production of essential oils was developed through establishment and elicitation of adventitious roots (AR) in a medicinally important plant Artemisia amygdalina D. The results indicated that leaf explants cultured on solid Murashige and Skoog (MS) media supplemented with 1.0 mg/L α- naphthalene acetic acid (NAA) and 4% sucrose instigated the higher AR induction frequency (90 ± 4.25) and maximum AR biomass (fresh biomass: 17.7 g/L). Furthermore, in the AR when transiently elicited with different elicitors for different time periods, methyl jasmonate (Me-J: 0.5 mg/L) resulted in the higher production of total phenolic content (TPC: 3.6 mg), total flavonoid content (TFC: 2.3 mg) and phenylalanine ammonia-lyase (PAL: 4.8 U/g×FW) activity, respectively. Nonetheless, considerable levels of the major bioactive compounds such as α-thujene (6.8%), α-pinene (8.3%), 1,8-cineole (16.2%), camphor (8.4%) and verbenole (10.2%) were recorded in the Me-J treated AR. Thus, a feasible protocol for production of essential oils through AR in A. amygdalina was established, which can be exploited for commercial production of the industrially important terpenes. Full article

(This article belongs to the Special Issue Essential Oils: From Phytochemistry to Ecophysiological Significances and Their Applications)

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15 pages, 1045 KiB

Open AccessArticle

Water Regime and Nitrogen Management to Cope with Wheat Yield Variability under the Mediterranean Conditions of Southern Portugal

by Manuel Patanita, Alexandra Tomaz, Tiago Ramos, Patrícia Oliveira, Luís Boteta and José Dôres

Plants 2019, 8(10), 429; https://doi.org/10.3390/plants8100429 - 19 Oct 2019

Cited by 8 | Viewed by 3039

Abstract

Global climate change accentuates the seasonal and interannual irregularity of temperature and precipitation of the Mediterranean climate. The consequences of this variability on wheat production are felt on its development cycle and productivity, making the production chain of this crop vulnerable to the [...] Read more.

Global climate change accentuates the seasonal and interannual irregularity of temperature and precipitation of the Mediterranean climate. The consequences of this variability on wheat production are felt on its development cycle and productivity, making the production chain of this crop vulnerable to the occurrence of years with abnormal distributions of precipitation and with extreme temperatures. Adaptation strategies like irrigation or fertilization can help to cope with the negative impacts of climate uncertainty. This study evaluated the effects of water regime and nitrogen (N) fertilization techniques on wheat production in southern Portugal based on the results of three trials conducted in two agricultural years (2016/2017 and 2017/2018) with contrasting climate conditions. Phenology and yield were evaluated by comparing water regimes (R1, full irrigation; R2, supplemental irrigation at four stages: start of stem extension, booting, anthesis, grain filling; R0, rainfed (in 2017/2018)) and N fertilization splitting/timing and type (conventional and enhanced efficiency fertilizers (EEFs): controlled-release N, stabilized with nitrification inhibitor, and stabilized with urease inhibitor). Significant effects of water regime on grain yield were obtained in 2016/2017, a year with extreme aridity and high water requirements felt from the tillering stage, in the trial with conventional fertilizers. In 2017/2018, when a beneficial seasonal rainfall distribution occurred, water regime did not influence grain yield, pointing to the feasibility of supplementary irrigation to maximize water productivity. Nitrogen fertilization influenced yield and its components, with the highest values of grain yield being obtained with conventional fertilizer. Regardless of the possible effects on grain quality, the use of EEF did not prove to have an indisputable effect on wheat yield in the conditions under which the trials were conducted. Comparison of the results in the two years accentuates the need to continue the evaluation of the influence of agronomic management in wheat production in the context of adaptation to the climatic uncertainty in Mediterranean regions. Full article

(This article belongs to the Special Issue Plants Reacts to the Changing Environment)

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17 pages, 1918 KiB

Open AccessArticle

Exogenous Tebuconazole and Trifloxystrobin Regulates Reactive Oxygen Species Metabolism Toward Mitigating Salt-Induced Damages in Cucumber Seedling

by Sayed Mohammad Mohsin, Mirza Hasanuzzaman, M. H. M. Borhannuddin Bhuyan, Khursheda Parvin and Masayuki Fujita

Plants 2019, 8(10), 428; https://doi.org/10.3390/plants8100428 - 18 Oct 2019

Cited by 29 | Viewed by 4368

Abstract

The present study investigated the role of tebuconazole (TEB) and trifloxystrobin (TRI) on cucumber plants (Cucumis sativus L. cv. Tokiwa) under salt stress (60 mM NaCl). The cucumber plants were grown semi-hydroponically in a glasshouse. Plants were exposed to two different doses [...] Read more.

The present study investigated the role of tebuconazole (TEB) and trifloxystrobin (TRI) on cucumber plants (Cucumis sativus L. cv. Tokiwa) under salt stress (60 mM NaCl). The cucumber plants were grown semi-hydroponically in a glasshouse. Plants were exposed to two different doses of fungicides (1.375 µM TEB + 0.5 µM TRI and 2.75 µM TEB + 1.0 µM TRI) solely and in combination with NaCl (60 mM) for six days. The application of salt phenotypically deteriorated the cucumber plant growth that caused yellowing of the whole plant and significantly destructed the contents of chlorophyll and carotenoids. The oxidative damage was created under salinity by increasing the contents of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and electrolytic leakage (EL) resulting in the disruption of the antioxidant defense system. Furthermore, in the leaves, stems, and roots of cucumber plants increased Na⁺ content was observed under salt stress, whereas the K⁺/Na⁺ ratio and contents of K⁺, Ca²⁺, and Mg²⁺ decreased. In contrast, the exogenous application of TEB and TRI reduced the contents of MDA, H₂O₂, and EL by improving the activities of enzymatic and non-enzymatic antioxidants. In addition, ion homeostasis was regulated by reducing Na⁺ uptake and enhanced K⁺ accumulation and the K⁺/Na⁺ ratio after application of TEB and TRI. Therefore, this study indicates that the exogenous application of TEB and TRI enhanced salt tolerance in cucumber plants by regulating reactive oxygen species production and antioxidant defense systems. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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26 pages, 4806 KiB

Open AccessArticle

Selenium Application During Radish (Raphanus sativus) Plant Development Alters Glucosinolate Metabolic Gene Expression and Results in the Production of 4-(methylseleno)but-3-enyl glucosinolate

by Marian McKenzie, Adam Matich, Donald Hunter, Azadeh Esfandiari, Stephen Trolove, Ronan Chen and Ross Lill

Plants 2019, 8(10), 427; https://doi.org/10.3390/plants8100427 - 18 Oct 2019

Cited by 15 | Viewed by 3680

Abstract

Selenium (Se) is an essential micronutrient for human health, entering the diet mainly through the consumption of plant material. Members of the Brassicaceae are Se-accumulators that can accumulate up to 1g Se kg⁻¹ dry weight (DW) from the environment without apparent ill [...] Read more.

Selenium (Se) is an essential micronutrient for human health, entering the diet mainly through the consumption of plant material. Members of the Brassicaceae are Se-accumulators that can accumulate up to 1g Se kg⁻¹ dry weight (DW) from the environment without apparent ill effect. The Brassicaceae also produce glucosinolates (GSLs), sulfur (S)-rich compounds that benefit human health. Radish (Raphanus sativus) has a unique GSL profile and is a Se-accumulating species that is part of the human diet as sprouts, greens and roots. In this report we describe the effects of Se-fertilisation on GSL production in radish during five stages of early development (from seed to mature salad greens) and on the transcript abundance of eight genes encoding enzymes involved in GSL metabolism. We tentatively identified (by tandem mass spectrometry) the selenium-containing glucosinolate, 4-(methylseleno)but-3-enyl glucosinolate, with the double bond geometry not resolved. Two related isothiocyanates were tentatively identified by Gas Chromatography-Mass Spectrometry as (E/Z?) isomers of 4-(methylseleno)but-3-enyl isothiocyanate. Se fertilisation of mature radish led to the presence of selenoglucosinolates in the seed. While GSL concentration generally reduced during radish development, GSL content was generally not affected by Se fertilisation, aside from the indole GSL, indol-3-ylmethyl glucosinolate, which increased on Se treatment, and the Se-GSLs, which significantly increased during development. The transcript abundance of genes involved in aliphatic GSL biosynthesis declined with Se treatment while that of genes involved in indole GSL biosynthesis tended to increase. APS kinase transcript abundance increased significantly in three of the four developmental stages following Se treatment. The remaining genes investigated were not significantly changed following Se treatment. We hypothesise that increased APS kinase expression in response to Se treatment is part of a general protection mechanism controlling the uptake of S and the production of S-containing compounds such as GSLs. The upregulation of genes encoding enzymes involved in indole GSL biosynthesis and a decrease in those involved in aliphatic GSL biosynthesis may be part of a similar mechanism protecting the plant’s GSL complement whilst limiting the amount of Se-GSLs produced. Full article

(This article belongs to the Special Issue Selenium Metabolism and Accumulation in Plants)

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13 pages, 2002 KiB

Open AccessFeature PaperArticle

Do No Harm: Efficacy of a Single Herbicide Application to Control an Invasive Shrub While Minimizing Collateral Damage to Native Species

by David J. Gibson, Lindsay A. Shupert and Xian Liu

Plants 2019, 8(10), 426; https://doi.org/10.3390/plants8100426 - 18 Oct 2019

Cited by 9 | Viewed by 3080

Abstract

Control of invasive exotic species in restorations without compromising the native plant community is a challenge. Efficacy of exotic species control needs to consider collateral effects on the associated plant community. We asked (1) if short-term control of a dominant exotic invasive, Lespedeza [...] Read more.

Control of invasive exotic species in restorations without compromising the native plant community is a challenge. Efficacy of exotic species control needs to consider collateral effects on the associated plant community. We asked (1) if short-term control of a dominant exotic invasive, Lespedeza cuneata in grassland restorations allows establishment of a more diverse native plant community, and (2) if control of the exotic and supplemental seed addition allows establishment of native species. A manipulative experiment tested the effects of herbicide treatments (five triclopyr and fluroxypyr formulations plus an untreated control) and seed addition (and unseeded control) on taxonomic and phylogenetic diversity, and community composition of restored grasslands in three sites over three years. We assessed response of L. cuneata through stem density counts, and response of the plant community through estimates of canopy cover. Herbicide treatments reduced the abundance of the exotic in the first field season leading to a less dispersed community composition compared with untreated controls, with the exotic regaining dominance by the third year. Supplemental seed addition did not provide extra resistance of the native community to reinvasion of the exotic. The communities were phylogenetically over-dispersed, but there was a short-term shift to lower phylogenetic diversity in response to herbicides consistent with a decrease in biotic filtering. Native plant communities in these grassland restorations were resilient to short-term reduction in abundance of a dominant invasive even though it was insufficient to provide an establishment window for native species establishment. Full article

(This article belongs to the Special Issue Invasive Plants)

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17 pages, 2098 KiB

Open AccessArticle

Gas Chromatography-Mass Spectrometry and Single Nucleotide Polymorphism-Genotype-By-Sequencing Analyses Reveal the Bean Chemical Profiles and Relatedness of Coffea canephora Genotypes in Nigeria

by Chinyere F. Anagbogu, Christopher O. Ilori, Ranjana Bhattacharjee, Olufemi O. Olaniyi and Diane M. Beckles

Plants 2019, 8(10), 425; https://doi.org/10.3390/plants8100425 - 18 Oct 2019

Cited by 4 | Viewed by 2799

Abstract

The flavor and health benefits of coffee (Coffea spp.) are derived from the metabolites that accumulate in the mature bean. However, the chemical profiles of many C. canephora genotypes remain unknown, even as the production of these coffee types increases globally. Therefore, [...] Read more.

The flavor and health benefits of coffee (Coffea spp.) are derived from the metabolites that accumulate in the mature bean. However, the chemical profiles of many C. canephora genotypes remain unknown, even as the production of these coffee types increases globally. Therefore, we used Gas Chromatography-Mass Spectrophotometry to determine the chemical composition of C. canephora genotypes in Nigeria—those conserved in germplasm repositories and those cultivated by farmers. GC-MS revealed 340 metabolites in the ripe beans, with 66 metabolites differing (p-value < 0.05) across the represented group. Univariate and multivariate approaches showed that the ‘Niaouli’ genotypes could be clearly distinguished from ‘Kouillou’ and ‘Java’ genotypes, while there was almost no distinction between ‘Kouillou’ and ‘Java,’. Varietal genotyping based on bean metabolite profiling was synchronous with that based on genome-wide Single Nucleotide Polymorphism analysis. Across genotypes, the sucrose-to-caffeine ratio was low, a characteristic indicative of low cup quality. The sucrose-to-caffeine ratio was also highly correlated, indicative of common mechanisms regulating the accumulation of these compounds. Nevertheless, this strong correlative link was broken within the ‘Niaouli’ group, as caffeine and sucrose content were highly variable among these genotypes. These ‘Niaouli’ genotypes could therefore serve as useful germplasm for starting a Nigerian C. canephora quality improvement breeding program. Full article

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15 pages, 2639 KiB

Open AccessArticle

Climatic Niche Shift during Azolla filiculoides Invasion and Its Potential Distribution under Future Scenarios

by Argantonio Rodríguez-Merino, Rocío Fernández-Zamudio, Pablo García-Murillo and Jesús Muñoz

Plants 2019, 8(10), 424; https://doi.org/10.3390/plants8100424 - 18 Oct 2019

Cited by 10 | Viewed by 3406

Abstract

In order to prevent future biological invasions, it is crucial to know non-native species distributions. We evaluated the potential global distribution of Azolla filiculoides, a free-floating macrophyte native to the Americas by using species distribution models and niche equivalency tests to analyze [...] Read more.

In order to prevent future biological invasions, it is crucial to know non-native species distributions. We evaluated the potential global distribution of Azolla filiculoides, a free-floating macrophyte native to the Americas by using species distribution models and niche equivalency tests to analyze the degree of niche overlap between the native and invaded ranges of the species. The models were projected under two future emission scenarios, three global circulation models and two time periods. Our results indicate a possible niche shift between the distribution ranges of the species, indicating that A. filiculoides can adapt to novel environmental conditions derived from climatic differences during the invasion process. Our models also show that the future potential distribution of A. filiculoides will decrease globally, although the species could colonize new vulnerable regions where it is currently absent. We highlight that species occurrence records in the invaded area are necessary to generate accurate models, which will, in turn, improve our ability to predict potential invasion risk areas. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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15 pages, 2291 KiB

Open AccessArticle

Physiological and Biochemical Responses of Orange Trees to Different Deficit Irrigation Regimes

by Ivana Puglisi, Elisabetta Nicolosi, Daniela Vanella, Angela Roberta Lo Piero, Fiorella Stagno, Daniela Saitta, Giancarlo Roccuzzo, Simona Consoli and Andrea Baglieri

Plants 2019, 8(10), 423; https://doi.org/10.3390/plants8100423 - 17 Oct 2019

Cited by 23 | Viewed by 3396

Abstract

The article presents the results of research consisting of the application of deficit irrigation (DI) criteria, combined with the adoption of micro-irrigation methods, on orange orchards (Citrus sinensis (L.) Osbeck) in Sicily (Italy) during the irrigation season of 2015. Regulated deficit irrigation [...] Read more.

The article presents the results of research consisting of the application of deficit irrigation (DI) criteria, combined with the adoption of micro-irrigation methods, on orange orchards (Citrus sinensis (L.) Osbeck) in Sicily (Italy) during the irrigation season of 2015. Regulated deficit irrigation (RDI, T3) and partial root-zone drying (PRD, T4) strategies were compared with full irrigation (T1) and sustained deficit irrigation (SDI, T2) treatments in terms of physiological, biochemical, and productive crop response. A geophysical survey (electrical resistivity tomography, ERT) was carried out to identify a link between the percentages of drying soil volume in T4 with leaves abscisic acid (ABA) signal. Results highlight that the orange trees physiological response to water stress conditions did not show particular differences among the different irrigation treatments, not inducing detrimental effects on crop production features. ABA levels in leaves were rather constant in all the treatments, except in T4 during late irrigation season. ERT technique identified that prolonged drying cycles during alternate PRD exposed more roots to severe soil drying, thus increasing leaf ABA accumulation. Full article

(This article belongs to the Section Plant Physiology and Metabolism)

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12 pages, 2960 KiB

Open AccessCommunication

Exploration of Floral Volatile Organic Compounds in Six Typical Lycoris taxa by GC-MS

by Tingting Shi, Yuanzheng Yue, Man Shi, Min Chen, Xiulian Yang and Lianggui Wang

Plants 2019, 8(10), 422; https://doi.org/10.3390/plants8100422 - 17 Oct 2019

Cited by 16 | Viewed by 4093

Abstract

Lycoris, which is known as the ‘Chinese tulip,’ has diverse flower colors and shapes, and some species have a delicate fragrance. However, limited studies have reported the volatile organic compounds (VOCs) of Lycoris. In this study, headspace solid-phase microextraction combined with [...] Read more.

Lycoris, which is known as the ‘Chinese tulip,’ has diverse flower colors and shapes, and some species have a delicate fragrance. However, limited studies have reported the volatile organic compounds (VOCs) of Lycoris. In this study, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry was used to analyze the floral VOCs of six typical Lycoris taxa. Thirty-two VOCs were identified, including terpenoids, alcohols, esters, aldehydes, ketones, and phenols. The aldehyde and terpenoid contents in Lycoris aurea were higher than in the other taxa, and the ester and alcohol contents in L. sprengeri were the highest compared to all taxa tested. Compared with other species and cultivars, L. longituba and L. longituba var. flava were the two most scented taxa and the VOCs were dominated by terpenoids and esters. L. radiate and L. chinensis were two unscented taxa and, accordingly, the VOC content was weak. A partial least squares discriminate analysis of the floral VOCs among the six Lycoris taxa showed that the six taxa could be successfully separated. Moreover, the VOCs of L. longituba and L. longituba var. flava clustered together. β-Ocimene was verified as the most important aroma compound, as determined via the calculation of the variable importance in projection values and significance analysis. β-Ocimene and its trans isomer, trans-β-ocimene, had a high relative content in L. longituba, L. longituba var. flava, L. aurea, and L. chinensis but were not detected in L. sprengeri and L. radiata. These results indicate that floral VOCs might be selected during the evolutional processes of Lycoris, and β-ocimene could be the most typical VOC among the different Lycoris taxa. Full article

(This article belongs to the Section Plant Physiology and Metabolism)

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27 pages, 12634 KiB

Open AccessArticle

Global Actions for Managing Cactus Invasions

by Ana Novoa, Giuseppe Brundu, Michael D. Day, Vicente Deltoro, Franz Essl, Llewellyn C. Foxcroft, Guillaume Fried, Haylee Kaplan, Sabrina Kumschick, Sandy Lloyd, Elizabete Marchante, Hélia Marchante, Iain D. Paterson, Petr Pyšek, David M. Richardson, Arne Witt, Helmuth G. Zimmermann and John R. U. Wilson

Plants 2019, 8(10), 421; https://doi.org/10.3390/plants8100421 - 16 Oct 2019

Cited by 17 | Viewed by 5746

Abstract

The family Cactaceae Juss. contains some of the most widespread and damaging invasive alien plant species in the world, with Australia (39 species), South Africa (35) and Spain (24) being the main hotspots of invasion. The Global Cactus Working Group (IOBC GCWG) was [...] Read more.

The family Cactaceae Juss. contains some of the most widespread and damaging invasive alien plant species in the world, with Australia (39 species), South Africa (35) and Spain (24) being the main hotspots of invasion. The Global Cactus Working Group (IOBC GCWG) was launched in 2015 to improve international collaboration and identify key actions that can be taken to limit the impacts caused by cactus invasions worldwide. Based on the results of an on-line survey, information collated from a review of the scientific and grey literature, expertise of the authors, and because invasiveness appears to vary predictably across the family, we (the IOBC GCWG): (1) recommend that invasive and potentially invasive cacti are regulated, and to assist with this, propose five risk categories; (2) recommend that cactus invasions are treated physically or chemically before they become widespread; (3) advocate the use of biological control to manage widespread invasive species; and (4) encourage the development of public awareness and engagement initiatives to integrate all available knowledge and perspectives in the development and implementation of management actions, and address conflicts of interest, especially with the agricultural and ornamental sectors. Implementing these recommendations will require global co-operation. The IOBC GCWG aims to assist with this process through the dissemination of information and experience. Full article

(This article belongs to the Special Issue Invasive Plants)

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13 pages, 641 KiB

Open AccessEditor’s ChoiceReview

Heterophylly: Phenotypic Plasticity of Leaf Shape in Aquatic and Amphibious Plants

by Gaojie Li, Shiqi Hu, Hongwei Hou and Seisuke Kimura

Plants 2019, 8(10), 420; https://doi.org/10.3390/plants8100420 - 16 Oct 2019

Cited by 49 | Viewed by 17754

Abstract

Leaves show great diversity in shape, size, and color in nature. Interestingly, many plant species have the ability to alter their leaf shape in response to their surrounding environment. This phenomenon is termed heterophylly, and is thought to be an adaptive feature to [...] Read more.

Leaves show great diversity in shape, size, and color in nature. Interestingly, many plant species have the ability to alter their leaf shape in response to their surrounding environment. This phenomenon is termed heterophylly, and is thought to be an adaptive feature to environmental heterogeneity in many cases. Heterophylly is widespread among land plants, and is especially dominant in aquatic and amphibious plants. Revealing the mechanisms underlying heterophylly would provide valuable insight into the interaction between environmental conditions and plant development. Here, we review the history and recent progress of research on heterophylly in aquatic and amphibious plants. Full article

(This article belongs to the Special Issue From Genes to Shape and Function: Leaf Morphogenesis at Play)

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10 pages, 2510 KiB

Open AccessArticle

Efficient Characterization of Tetraploid Watermelon

by Na Zhang, Yaning Bao, Zhouli Xie, Xing Huang, Yuhong Sun, Gang Feng, Hongxia Zeng, Jian Ren, Yuhua Li, Jianshun Xiong, Wei Chen, Chao Yan and Mi Tang

Plants 2019, 8(10), 419; https://doi.org/10.3390/plants8100419 - 16 Oct 2019

Cited by 19 | Viewed by 8183

Abstract

Watermelon (Citrullus lanatus (Thunb.) Matsum. &Nakai) is an economic crop, which is widely cultivated around the world. The ploidy study of watermelon has an important role in field breeding and production, therefore, timely and convenient ploidy detection is necessary to accelerate its [...] Read more.

Watermelon (Citrullus lanatus (Thunb.) Matsum. &Nakai) is an economic crop, which is widely cultivated around the world. The ploidy study of watermelon has an important role in field breeding and production, therefore, timely and convenient ploidy detection is necessary to accelerate its application. Traditionally, the ploidy of watermelon was determined by a series of time-consuming, expensive, and less efficient methods. In this study, we developed a more efficient method to simplify and accelerate the polyploidy identification in watermelons. We first confirmed the ploidy of watermelon by traditional tetraploid morphological features and well-established flow cytometry (FCM). Then we developed a reliable real-time quantitative PCR (qPCR) technique by quantifying the highly conserved 5S rDNA sequence and its copy numbers. This technique requires less sample collection and has comparable accuracy to FCM, it accelerates the analysis process and provides a new method for the identification of polyploidy of watermelon. Full article

(This article belongs to the Collection Doubled Haploid Technology in Plant Breeding)

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12 pages, 1531 KiB

Open AccessArticle

Vegetation Heterogeneity Effects on Soil Macro-Arthropods in an Alpine Tundra of the Changbai Mountains, China

by Yan Tao, Zhongqiang Wang, Chen Ma, Hongshi He, Jiawei Xu, Yinghua Jin, Haixia Wang and Xiaoxue Zheng

Plants 2019, 8(10), 418; https://doi.org/10.3390/plants8100418 - 16 Oct 2019

Cited by 9 | Viewed by 2804

Abstract

The harsh environmental conditions in alpine tundra exert a significant influence on soil macro-arthropod communities, yet few studies have been performed regarding the effects of vegetation heterogeneity on these communities. In order to better understand this question, a total of 96 soil macro-arthropod [...] Read more.

The harsh environmental conditions in alpine tundra exert a significant influence on soil macro-arthropod communities, yet few studies have been performed regarding the effects of vegetation heterogeneity on these communities. In order to better understand this question, a total of 96 soil macro-arthropod samples were collected from four habitats in the Changbai Mountains in China, namely, the Vaccinium uliginosum habitat, Sanguisorba sitchensis habitat, Rhododendron aureum habitat, and Deyeuxia angustifolia habitat. The results revealed that the taxonomic composition of the soil macro-arthropods varied among the habitats, and that dissimilarities existed in these communities. The abundance, richness and diversity in the D. angustifolia habitat were all at their maximum during the sampling period. The vegetation heterogeneity affected the different taxa of the soil macro-arthropods at various levels. In addition, the vegetation heterogeneity had direct effects not only on soil macro-arthropod communities, but also indirectly impacted the abundance, richness and diversity by altering the soil fertility and soil texture. Overall, our results provide experimental evidence that vegetation heterogeneity can promote the abundance, richness and diversity of soil macro-arthropods, yet the responses of soil macro-arthropods to vegetation heterogeneity differed among their taxa. Full article

(This article belongs to the Section Plant Ecology)

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16 pages, 351 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Non-Target-Site Resistance to Herbicides: Recent Developments

by Mithila Jugulam and Chandrima Shyam

Plants 2019, 8(10), 417; https://doi.org/10.3390/plants8100417 - 15 Oct 2019

Cited by 106 | Viewed by 7073

Abstract

Non-target-site resistance (NTSR) to herbicides in weeds can be conferred as a result of the alteration of one or more physiological processes, including herbicide absorption, translocation, sequestration, and metabolism. The mechanisms of NTSR are generally more complex to decipher than target-site resistance (TSR) [...] Read more.

Non-target-site resistance (NTSR) to herbicides in weeds can be conferred as a result of the alteration of one or more physiological processes, including herbicide absorption, translocation, sequestration, and metabolism. The mechanisms of NTSR are generally more complex to decipher than target-site resistance (TSR) and can impart cross-resistance to herbicides with different modes of action. Metabolism-based NTSR has been reported in many agriculturally important weeds, although reduced translocation and sequestration of herbicides has also been found in some weeds. This review focuses on summarizing the recent advances in our understanding of the physiological, biochemical, and molecular basis of NTSR mechanisms found in weed species. Further, the importance of examining the co-existence of TSR and NTSR for the same herbicide in the same weed species and influence of environmental conditions in the altering and selection of NTSR is also discussed. Knowledge of the prevalence of NTSR mechanisms and co-existing TSR and NTSR in weeds is crucial for designing sustainable weed management strategies to discourage the further evolution and selection of herbicide resistance in weeds. Full article

(This article belongs to the Special Issue Herbicide Resistance in Plants)

25 pages, 3123 KiB

Open AccessArticle

Impact of Combined Heat and Drought Stress on the Potential Growth Responses of the Desert Grass Artemisia sieberi alba: Relation to Biochemical and Molecular Adaptation

by Haifa Abdulaziz S. Alhaithloul

Plants 2019, 8(10), 416; https://doi.org/10.3390/plants8100416 - 15 Oct 2019

Cited by 43 | Viewed by 5426

Abstract

Artemisia sieberi alba is one of the important plants frequently encountered by the combined effect of drought and heat stress. In the present study, we investigated the individual and combined effect of drought and heat stress on growth, photosynthesis, oxidative damage, and gene [...] Read more.

Artemisia sieberi alba is one of the important plants frequently encountered by the combined effect of drought and heat stress. In the present study, we investigated the individual and combined effect of drought and heat stress on growth, photosynthesis, oxidative damage, and gene expression in A. sieberi alba. Drought and heat stress triggered oxidative damage by increasing the accumulation of hydrogen peroxide, and therefore electrolyte leakage. The accumulation of secondary metabolites, such as phenol and flavonoids, and proline, mannitol, inositol, and sorbitol, was increased due to drought and heat stress exposure. Photosynthetic attributes including chlorophyll synthesis, stomatal conductance, transpiration rate, photosynthetic efficiency, and chlorophyll fluorescence parameters were drastically reduced due to drought and heat stress exposure. Relative water content declined significantly in stressed plants, which was evident by the reduced leaf water potential and the water use efficiency, therefore, affecting the overall growth performance. Relative expression of aquaporin (AQP), dehydrin (DHN1), late embryogenesis abundant (LEA), osmotin (OSM-34), and heat shock proteins (HSP70) were significantly higher in stressed plants. Drought triggered the expression of AQP, DHN1, LEA, and OSM-34 more than heat, which improved the HSP70 transcript levels. A. sieberi alba responded to drought and heat stress by initiating key physio-biochemical and molecular responses, which were distinct in plants exposed to a combination of drought and heat stress. Full article

(This article belongs to the Section Plant Physiology and Metabolism)

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13 pages, 5177 KiB

Open AccessArticle

Characterization and Mapping of a Novel Premature Leaf Senescence Mutant in Common Tobacco (Nicotiana tabacum L.)

by Xiaoming Gao, Xinru Wu, Guanshan Liu, Zenglin Zhang, Jiangtao Chao, Zhiyuan Li, Yongfeng Guo and Yuhe Sun

Plants 2019, 8(10), 415; https://doi.org/10.3390/plants8100415 - 15 Oct 2019

Cited by 6 | Viewed by 3930

Abstract

As the last stage of plant development, leaf senescence has a great impact on plant’s life cycle. Genetic manipulation of leaf senescence has been used as an efficient approach in improving the yield and quality of crop plants. Here we describe an ethyl [...] Read more.

As the last stage of plant development, leaf senescence has a great impact on plant’s life cycle. Genetic manipulation of leaf senescence has been used as an efficient approach in improving the yield and quality of crop plants. Here we describe an ethyl methane sulfonate (EMS) mutagenesis induced premature leaf senescence mutant yellow leaf 1 (yl1) in common tobacco (Nicotiana tabacum L.). The yl1 plants displayed early leaf yellowing. Physiological parameters and marker genes expression indicated that the yl1 phenotype was caused by premature leaf senescence. Genetic analyses indicated that the yl1 phenotype was controlled by a single recessive gene that was subsequently mapped to a specific interval of tobacco linkage group 11 using simple sequence repeat (SSR) markers. Exogenous plant hormone treatments of leaves showed that the yl1 mutant was more sensitive to ethylene and jasmonic acid than the wild type. No similar tobacco premature leaf senescence mutants have been reported. This study laid a foundation for finding the gene controlling the mutation phenotype and revealing the molecular regulation mechanism of tobacco leaf senescence in the next stage. Full article

(This article belongs to the Special Issue Genomics for Plant Breeding)

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14 pages, 1333 KiB

Open AccessArticle

Lipid Thermal Fingerprints of Long-term Stored Seeds of Brassicaceae

by Sara Mira, Jayanthi Nadarajan, Udayangani Liu, Maria Elena González-Benito and Hugh W. Pritchard

Plants 2019, 8(10), 414; https://doi.org/10.3390/plants8100414 - 14 Oct 2019

Cited by 20 | Viewed by 3406

Abstract

Thermal fingerprints for seeds of 20 crop wild relatives of Brassicaceae stored for 8 to 44 years at the Plant Germplasm Bank—Universidad Politécnica de Madrid and the Royal Botanic Gardens, Kew’s Millennium Seed Bank—were generated using differential scanning calorimetry (DSC) and analyzed in [...] Read more.

Thermal fingerprints for seeds of 20 crop wild relatives of Brassicaceae stored for 8 to 44 years at the Plant Germplasm Bank—Universidad Politécnica de Madrid and the Royal Botanic Gardens, Kew’s Millennium Seed Bank—were generated using differential scanning calorimetry (DSC) and analyzed in relation to storage stability. Relatively poor storing oily seeds at −20 °C tended to have lipids with crystallization and melting transitions spread over a wide temperature range (c. 40 °C) that spanned the storage temperature, plus a melting end temperature of around 15 °C. We postulated that in dry storage, the variable longevity in Brassicaceae seeds could be associated with the presence of a metastable lipid phase at the temperature at which they are being stored. Consistent with that, when high-quality seed samples of various species were assessed after banking at −5 to −10 °C for c. 40 years, melting end temperatures were observed to be much lower (c. 0 to −30 °C) and multiple lipid phases did not occur at the storage temperature. We conclude that multiple features of the seed lipid thermal fingerprint could be used as biophysical markers to predict potential poor performance of oily seeds during long-term, decadal storage. Full article

(This article belongs to the Special Issue Linking Seed Biology to Plant Preservation: New Advances and Perspectives)

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16 pages, 4777 KiB

Open AccessArticle

The Effect of Cadmium on the Activity of Stress-Related Enzymes and the Ultrastructure of Pea Roots

by Katarzyna Głowacka, Anna Źróbek-Sokolnik, Adam Okorski and Janusz Najdzion

Plants 2019, 8(10), 413; https://doi.org/10.3390/plants8100413 - 14 Oct 2019

Cited by 33 | Viewed by 4332

Abstract

The analysis of the effects of cadmium (Cd) on plant cells is crucial to understand defense mechanisms and adaptation strategies of plants against Cd toxicity. In this study, we examined stress-related enzyme activities after one and seven days of Cd application and the [...] Read more.

The analysis of the effects of cadmium (Cd) on plant cells is crucial to understand defense mechanisms and adaptation strategies of plants against Cd toxicity. In this study, we examined stress-related enzyme activities after one and seven days of Cd application and the ultrastructure of roots of Pisum sativum L. after seven days of Cd treatment (10, 50, 100, and 200 μM CdSO₄). Our results showed that phenylalanine ammonia-lyase (PAL) activity and the amount of Cd accumulated in the roots were significantly positively correlated with the Cd concentration used in our experiment. However, Cd caused a decrease of all studied antioxidative enzyme activities (i.e., catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX)). The analysis of the ultrastructure (TEM) showed various responses to Cd, depending on Cd concentrations. In general, lower Cd concentrations (50 and 100 μM CdSO₄) mostly resulted in increased amounts of oil bodies, plastolysomes and the accumulation of starch granules in plastids. Meanwhile, roots treated with a higher concentration of Cd (200 μM CdSO₄) additionally triggered protective responses such as an increased deposition of suberin lamellae in the endodermal cell walls. This indicates that Cd induces a complex defense response in root tissues. Full article

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19 pages, 1840 KiB

Open AccessArticle

Exhibition of Local but Not Systemic Induced Phenolic Defenses in Vitis vinifera L. Affected by Brown Wood Streaking, Grapevine Leaf Stripe, and Apoplexy (Esca Complex)

by Piebiep Goufo, Ana C. Marques and Isabel Cortez

Plants 2019, 8(10), 412; https://doi.org/10.3390/plants8100412 - 14 Oct 2019

Cited by 9 | Viewed by 3906

Abstract

Balance between constitutive and induced responses provides plants flexibility to cope with biotic stresses. This study tested the hypothesis that invasion of grapevine wood by esca-associated fungi induces the production of defensive compounds as part of locally- and systemically-induced responses. In a vineyard, [...] Read more.

Balance between constitutive and induced responses provides plants flexibility to cope with biotic stresses. This study tested the hypothesis that invasion of grapevine wood by esca-associated fungi induces the production of defensive compounds as part of locally- and systemically-induced responses. In a vineyard, different symptomatic expressions of “Esca complex” in Vitis vinifera L. ‘Malvasia’ were evaluated in annual inspections. Then, levels of phenolics and fatty acids were determined in asymptomatic leaves of brown wood streaking (BWS) and grapevine leaf stripe (GLSD) vines, and in symptomatic leaves of GLSD and apoplectic vines; the results were compared with levels in healthy vines. In asymptomatic leaves of BWS and some GLSD vines, levels of phenolics decreased, independent of the total phenolic group. Such responses were usually associated with an increase in levels of linoleic, γ-linolenic and arachidonic acids, well-known signal transduction mediators. In symptomatic leaves, levels of phenolics increased, which is consistent with a locally-induced response; the onset of symptoms coincided with the highest increases e.g., 35% for quercetin-3-O-glucuronide. Thus, the long latency period between trunk invasion by fungi and visible foliar damage and the year-to-year fluctuation in symptomatic expressions observed with “Esca complex” might be partially attributed to a better utilization of constitutive defenses. Full article

(This article belongs to the Special Issue Decline of Mediterranean Fruit Crops and Forests Associated with Fungal Trunk Pathogens)

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28 pages, 1259 KiB

Open AccessEditor’s ChoiceReview

Transcription Factors Associated with Leaf Senescence in Crops

by Sofia Bengoa Luoni, Francisco H. Astigueta, Salvador Nicosia, Sebastian Moschen, Paula Fernandez and Ruth Heinz

Plants 2019, 8(10), 411; https://doi.org/10.3390/plants8100411 - 14 Oct 2019

Cited by 46 | Viewed by 7078

Abstract

Leaf senescence is a complex mechanism controlled by multiple genetic and environmental variables. Different crops present a delay in leaf senescence with an important impact on grain yield trough the maintenance of the photosynthetic leaf area during the reproductive stage. Additionally, because of [...] Read more.

Leaf senescence is a complex mechanism controlled by multiple genetic and environmental variables. Different crops present a delay in leaf senescence with an important impact on grain yield trough the maintenance of the photosynthetic leaf area during the reproductive stage. Additionally, because of the temporal gap between the onset and phenotypic detection of the senescence process, candidate genes are key tools to enable the early detection of this process. In this sense and given the importance of some transcription factors as hub genes in senescence pathways, we present a comprehensive review on senescence-associated transcription factors, in model plant species and in agronomic relevant crops. This review will contribute to the knowledge of leaf senescence process in crops, thus providing a valuable tool to assist molecular crop breeding. Full article

(This article belongs to the Special Issue Leaf Senescence)

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15 pages, 3049 KiB

Open AccessArticle

Complete Chloroplast Genomes of Ampelopsis humulifolia and Ampelopsis japonica: Molecular Structure, Comparative Analysis, and Phylogenetic Analysis

by Xiaolei Yu, Wei Tan, Huanyu Zhang, Han Gao, Wenxiu Wang and Xiaoxuan Tian

Plants 2019, 8(10), 410; https://doi.org/10.3390/plants8100410 - 14 Oct 2019

Cited by 25 | Viewed by 4073

Abstract

Ampelopsis humulifolia (A. humulifolia) and Ampelopsis japonica (A. japonica), which belong to the family Vitaceae, are valuably used as medicinal plants. The chloroplast (cp) genomes have been recognized as a convincing data for marker selection and phylogenetic studies. Therefore, [...] Read more.

Ampelopsis humulifolia (A. humulifolia) and Ampelopsis japonica (A. japonica), which belong to the family Vitaceae, are valuably used as medicinal plants. The chloroplast (cp) genomes have been recognized as a convincing data for marker selection and phylogenetic studies. Therefore, in this study we reported the complete cp genome sequences of two Ampelopsis species. Results showed that the cp genomes of A. humulifolia and A. japonica were 161,724 and 161,430 bp in length, respectively, with 37.3% guanine-cytosine (GC) content. A total of 114 unique genes were identified in each cp genome, comprising 80 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. We determined 95 and 99 small sequence repeats (SSRs) in A. humulifolia and A. japonica, respectively. The location and distribution of long repeats in the two cp genomes were identified. A highly divergent region of psbZ (Photosystem II reaction center protein Z) -trnG (tRNA-Glycine) was found and could be treated as a potential marker for Vitaceae, and then the corresponding primers were designed. Additionally, phylogenetic analysis showed that Vitis was closer to Tetrastigma than Ampelopsis. In general, this study provides valuable genetic resources for DNA barcoding marker identification and phylogenetic analyses of Ampelopsis. Full article

(This article belongs to the Special Issue Plant Bioinformatics)

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17 pages, 2750 KiB

Open AccessArticle

Leaf Production and Expansion: A Generalized Response to Drought Stresses from Cells to Whole Leaf Biomass—A Case Study in the Tomato Compound Leaf

by Garance Koch, Gaëlle Rolland, Myriam Dauzat, Alexis Bédiée, Valentina Baldazzi, Nadia Bertin, Yann Guédon and Christine Granier

Plants 2019, 8(10), 409; https://doi.org/10.3390/plants8100409 - 12 Oct 2019

Cited by 27 | Viewed by 4279

Abstract

It is clearly established that there is not a unique response to soil water deficit but that there are as many responses as soil water deficit characteristics: Drought intensity, drought duration, and drought position during plant cycle. For a same soil water deficit, [...] Read more.

It is clearly established that there is not a unique response to soil water deficit but that there are as many responses as soil water deficit characteristics: Drought intensity, drought duration, and drought position during plant cycle. For a same soil water deficit, responses can also differ on plant genotype within a same species. In spite of this variability, at least for leaf production and expansion processes, robust tendencies can be extracted from the literature when similar watering regimes are compared. Here, we present response curves and multi-scale dynamics analyses established on tomato plants exposed to different soil water deficit treatments. Results reinforce the trends already observed for other species: Reduction in plant leaf biomass under water stress was due to reduction in individual leaf biomass and areas whereas leaf production and specific leaf area were not affected. The dynamics of leaf expansion was modified both at the leaf and cell scales. Cell division and expansion were reduced by drought treatments as well as the endoreduplication process. Combining response curves analyses together with dynamic analyses of tomato compound leaf growth at different scales not only corroborate results on simple leaf responses to drought but also increases our knowledge on the cellular mechanisms behind leaf growth plasticity. Full article

(This article belongs to the Special Issue From Genes to Shape and Function: Leaf Morphogenesis at Play)

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21 pages, 1241 KiB

Open AccessReview

Molecular Analyses of the Distribution and Function of Diazotrophic Rhizobia and Methanotrophs in the Tissues and Rhizosphere of Non-Leguminous Plants

by Tadakatsu Yoneyama, Junko Terakado-Tonooka, Zhihua Bao and Kiwamu Minamisawa

Plants 2019, 8(10), 408; https://doi.org/10.3390/plants8100408 - 11 Oct 2019

Cited by 18 | Viewed by 10898

Abstract

Biological nitrogen fixation (BNF) by plants and its bacterial associations represent an important natural system for capturing atmospheric dinitrogen (N₂) and processing it into a reactive form of nitrogen through enzymatic reduction. The study of BNF in non-leguminous plants has been [...] Read more.

Biological nitrogen fixation (BNF) by plants and its bacterial associations represent an important natural system for capturing atmospheric dinitrogen (N₂) and processing it into a reactive form of nitrogen through enzymatic reduction. The study of BNF in non-leguminous plants has been difficult compared to nodule-localized BNF in leguminous plants because of the diverse sites of N₂ fixation in non-leguminous plants. Identification of the involved N₂-fixing bacteria has also been difficult because the major nitrogen fixers were often lost during isolation attempts. The past 20 years of molecular analyses has led to the identification of N₂ fixation sites and active nitrogen fixers in tissues and the rhizosphere of non-leguminous plants. Here, we examined BNF hotspots in six reported non-leguminous plants. Novel rhizobia and methanotrophs were found to be abundantly present in the free-living state at sites where carbon and energy sources were predominantly available. In the carbon-rich apoplasts of plant tissues, rhizobia such as Bradyrhizobium spp. microaerobically fix N₂. In paddy rice fields, methane molecules generated under anoxia are oxidized by xylem aerenchyma-transported oxygen with the simultaneous fixation of N₂ by methane-oxidizing methanotrophs. We discuss the effective functions of the rhizobia and methanotrophs in non-legumes for the acquisition of fixed nitrogen in addition to research perspectives. Full article

(This article belongs to the Special Issue Nitrogen-Fixing Plants )

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15 pages, 2083 KiB

Open AccessArticle

Night Temperature Affects the Growth, Metabolism, and Photosynthetic Gene Expression in Astragalus membranaceus and Codonopsis lanceolata Plug Seedlings

by Ya Liu, Xiuxia Ren and Byoung Ryong Jeong

Plants 2019, 8(10), 407; https://doi.org/10.3390/plants8100407 - 10 Oct 2019

Cited by 11 | Viewed by 3332

Abstract

Astragalus membranaceus and Codonopsis lanceolata are two important medical herbs used in traditional Oriental medicine for preventing cancer, obesity, and inflammation. Night temperature is an important factor that influences the plug seedling quality. However, little research has focused on how the night temperature [...] Read more.

Astragalus membranaceus and Codonopsis lanceolata are two important medical herbs used in traditional Oriental medicine for preventing cancer, obesity, and inflammation. Night temperature is an important factor that influences the plug seedling quality. However, little research has focused on how the night temperature affects the growth and development of plug seedlings of these two medicinal species. In this study, uniform plug seedlings were cultivated in three environmentally controlled chambers for four weeks under three sets of day/night temperatures (25/10 °C, 25/15 °C, or 25/20 °C), the same relative humidity (75%), photoperiod (12 h), and light intensity (150 μmol·m⁻²·s⁻¹ PPFD) provided by white LEDs. The results showed that night temperature had a marked influence on the growth and development of both species. The night temperature of 15 °C notably enhanced the quality of plug seedlings evidenced by the increased shoot, root, and leaf dry weights, stem diameter, and Dickson’s quality index. Moreover, a night temperature of 15 °C also stimulated and increased contents of primary and secondary metabolites, including soluble sugar, starch, total phenols and flavonoids. Furthermore, the 15 °C night temperature increased the chlorophyll content and stomatal conductance and decreased the hydrogen peroxide content. Analysis of the gene expression showed that granule-bound starch synthase (GBSS), ribulose bisphosphate carboxylase large chain (RBCL), and ferredoxin (FDX) were up-regulated when the night temperature was 15 °C. Taken together, the results suggested that 15 °C is the optimal night temperature for the growth and development of plug seedlings of A. membranaceus and C. lanceolata. Full article

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