Submit to Soil Systems Review for Soil Systems Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Special Issue "Rhizosphere Processes"

Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Soil Systems (ISSN 2571-8789).

Deadline for manuscript submissions: closed (1 October 2017) | Viewed by 32938

Share This Special Issue

Special Issue Editors

Dr. Angelia L. Seyfferth

E-Mail Website
Guest Editor

Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716, USA
Interests: soil biogeochemistry; trace-element and nutrient cycling; food security; advanced imaging techniques

Dr. E. Marie Muehe
E-Mail Website
Guest Editor

Helmholtz Center for Environmental Research UFZ, Department of Environmental Microbiology, 04103 Leipzig, Germany
Interests: plant-microbe-soil interaction in metal(loid)-contaminated environments, crop production and soil quality

Dr. Suzie M. Reichman

E-Mail Website
Guest Editor

Centre for Anthropogenic Pollution Impact and Management (CAPIM), School of Biosciences, University of Melbourne, Parkville, VIC 3010, Australia
Interests: soil chemistry; plant nutrition; rhizosphere chemistry; metal and metalloid bioavailability in soil; ecotoxicology and environmental impact assessment
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The rhizosphere is a dynamic interface between plants, soils, and microorganisms that plays a substantial role in global-scale processes. Exudation of C-rich compounds from roots influences rhizospheric geochemistry and microbial functioning. These processes, in turn, affect the cycling and plant-acquisition of nutrients (e.g., C, N, P, Fe) and toxic metal(loid)s (e.g., As, Cd, Hg), and to this end soil and water quality and food security. Understanding how these rhizosphere processes function independently, in concert, and in response to changing weather patterns will be increasingly important.

Authors are invited to submit their work on rhizosphere processes, including trace-element or nutrient cycling, biogeochemistry, plant-contaminant interactions and phytoremediation, plant-microbe interactions, ionomics, or metabolomics in the rhizosphere. A particular focus on linking rhizosphere processes to large-scale processes, such as carbon cycling, food security, and soil quality are encouraged.

Dr. Angelia L. Seyfferth
Dr. E. Marie Muehe
Dr. Suzie M. Reichman
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Soil Systems is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1500 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

biogeochemistry
plant roots
metals
nutrients
plant-microbe interactions
elemental cycling
soil quality

Published Papers (6 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

6 pages, 1701 KiB

Open AccessArticle

Effects of Iron Amendments on the Speciation of Arsenic in the Rice Rhizosphere after Drainage

and

Soils 2017, 1(1), 6; https://doi.org/10.3390/soils1010006 - 01 Dec 2017

Cited by 5 | Viewed by 5066

Abstract

Applications of iron- (Fe-) bearing materials represent an effective countermeasure for decreasing the dissolution of arsenic (As) in soil under anaerobic conditions. In this study, we investigated the effects of Fe amendments (ferrihydrite-based and zero-valent iron- (ZVI-) based materials) on the speciation of As in rice cultivated soils and root-attached materials including Fe plaque when the soil shifts from anaerobic to aerobic conditions. Rice (Oryza sativa L.) was cultivated in pots filled with soil under continuous flooding conditions, and root distribution in the soil was restricted inside a cylinder made by nylon mesh. Soil and root samples were collected after drainage at different growth stages of the rice plants, which are represented by intermittent drainage and drainage at harvest. The speciation of As was determined by As K-edge X-ray absorption near edge structure (XANES) spectroscopy. The proportion of arsenite did not differ between the bulk soil and root-attached materials including Fe plaque, whereas a larger proportion of dimethylarsinic acid was found in the root-attached materials regardless of the application of Fe amendments. Observation of soil thin-sections showed that the application of Fe amendments caused an increase in Fe (hydr)oxide deposition around the roots as well as on the soil particles. In addition to Fe (hydr)oxide, sulfide was found to be associated with As under anaerobic conditions, notably for the ZVI-amended soil at the time of intermittent drainage. The concentration of As in the soil solution and As uptake by rice grains decreased, while As speciation near the roots was not influenced by the application of Fe amendments. In conclusion, Fe amendments mitigated As dissolution in the soil solution by providing a sorption site for As in bulk soil without altering As speciation near the roots. Full article

(This article belongs to the Special Issue Rhizosphere Processes)

► Show Figures

Figure 1

5 pages, 3343 KiB

Open AccessArticle

Ectomycorrhizal Fungi and Mineral Interactions in the Rhizosphere of Scots and Red Pine Seedlings

Zsuzsanna Balogh-Brunstad

and

Soils 2017, 1(1), 5; https://doi.org/10.3390/soils1010005 - 19 Sep 2017

Cited by 6 | Viewed by 6992

Abstract

Ectomycorrhizal fungi and associated bacteria play a key role in plant-driven mineral weathering and uptake of mineral-derived nutrients in the rhizosphere. The goal of this study was to investigate the physical and chemical characteristics of bacteria-fungi-mineral interactions in biofilms of Scots and red pine rhizospheres. In three experiments, seedlings were grown in columns containing silica sand amended with biotite and calcium-feldspar, and inoculated with pure cultures of ectomycorrhizal fungi or a soil slurry. Uninoculated seedlings and unplanted abiotic columns served as controls. After nine months, the columns were destructively sampled and the minerals were analyzed using scanning electron and atomic force microscopy. Element release rates were determined from cation concentrations of input and output waters, soil exchange sites, and plant biomass, then normalized to geometric surface area of minerals in each column. The results revealed that various ectomycorrhizal fungal species stimulate silicate dissolution, and biofilm formation occurred at low levels, but direct surface attachment and etching by fungal hyphae was a minor contributor to the overall cation release from the minerals in comparison to other environmental conditions such as water applications (rain events), which varied among the experiments. This research highlights the importance of experimental design details for future exploration of these relationships. Full article

(This article belongs to the Special Issue Rhizosphere Processes)

► Show Figures

Figure 1

4 pages, 5369 KiB

Open AccessArticle

Molecular and Microscopic Insights into the Formation of Soil Organic Matter in a Red Pine Rhizosphere

and

Soils 2017, 1(1), 4; https://doi.org/10.3390/soils1010004 - 26 Aug 2017

Cited by 11 | Viewed by 6582

Abstract

Microbially-derived carbon inputs to soils play an important role in forming soil organic matter (SOM), but detailed knowledge of basic mechanisms of carbon (C) cycling, such as stabilization of organic C compounds originating from rhizodeposition, is scarce. This study aimed to investigate the stability of rhizosphere-produced carbon components in a model laboratory mesocosm of Pinus resinosa grown in a designed mineral soil mix with limited nutrients. We utilized a suite of advanced imaging and molecular techniques to obtain a molecular-level identification of newly-formed SOM compounds, and considered implications regarding their degree of long-term persistence. The microbes in this controlled, nutrient-limited system, without pre-existing organic matter, produced extracellular polymeric substances that formed associations with nutrient-bearing minerals and contributed to the microbial mineral weathering process. Electron microscopy revealed unique ultrastructural residual signatures of biogenic C compounds, and the increased presence of an amorphous organic phase associated with the mineral phase was evidenced by X-ray diffraction. These findings provide insight into the formation of SOM products in ecosystems, and show that the plant- and microbially-derived material associated with mineral matrices may be important components in current soil carbon models. Full article

(This article belongs to the Special Issue Rhizosphere Processes)

► Show Figures

Figure 1

3 pages, 2898 KiB

Open AccessArticle

Evidence for the Root-Uptake of Arsenite at Lateral Root Junctions and Root Apices in Rice (Oryza sativa L.)

Angelia L. Seyfferth

Jean Ross

and

Samuel M. Webb

Soils 2017, 1(1), 3; https://doi.org/10.3390/soils1010003 - 14 Aug 2017

Cited by 8 | Viewed by 4138

Abstract

The uptake of arsenite (As(III)_i) at the Casparian band via Lsi1 and Lsi2 Si transporters is responsible for ~75% of shoot As(III)_i uptake in rice and, therefore, ~25% of shoot As(III)_i is taken up by other transport pathways. We hypothesized that areas devoid of Casparian bands—lateral root junctions and root apices—can transport As(III)_i into roots. We analyzed the elemental distribution and As concentration, speciation, and localization in rice roots from soil-grown and solution-grown plants. With solution-grown plants dosed with As(III)_i, we sectioned roots as a function of distance from the root apex and analyzed the cross-sections using confocal microscopy coupled to synchrotron X-ray fluorescence imaging and spectroscopy. We observed elevated As(III)_i associated with lateral root junctions and root apices in rice. As(III)_i entered the stele at lateral root junctions and radially permeated the root interior in cross-sections 130–140 µm from the root apex that are devoid of Casparian bands. Our findings suggest that lateral root junctions and rice root apices are hot-spots for As(III)_i transport into rice roots, but the contribution to shoot As requires further research. Full article

(This article belongs to the Special Issue Rhizosphere Processes)

► Show Figures

Figure 1

2 pages, 4536 KiB

Open AccessArticle

Legacy of Rice Roots as Encoded in Distinctive Microsites of Oxides, Silicates, and Organic Matter

Daniel Said-Pullicino

and

Soils 2017, 1(1), 2; https://doi.org/10.3390/soils1010002 - 09 Aug 2017

Cited by 8 | Viewed by 5013

Abstract

Rice (Oryza sativa) is usually grown under flooded conditions, leading to anoxic periods in the soil. Rice plants transport oxygen via aerenchyma from the atmosphere to the roots. Driven by O₂ release into the rhizosphere, radial gradients of ferric Fe and co-precipitated organic substances are formed. Our study aimed at elucidating the composition and spatial extension of those gradients. Air-dried soil aggregates from a paddy field were embedded in epoxy resin, cut, and polished to produce cross sections. Reflected-light microscopy was used to identify root channels. With nano-scale secondary ion mass spectrometry (NanoSIMS), we investigated transects from root channels into the soil matrix and detected ¹²C⁻, ¹⁶O⁻, ¹²C¹⁴N⁻, ²⁸Si⁻, ²⁷Al¹⁶O⁻, and ⁵⁶Fe¹⁶O⁻ to distinguish between embedding resin, organic matter, oxides, and silicates. Image analyses reveal high occurrences of ⁵⁶Fe¹⁶O⁻ within and in close proximity of oxide-encrusted root cells, followed by a thin layer with high occurrences of ²⁷Al¹⁶O⁻ and ¹²C¹⁴N⁻. In two of the three transects, ²⁸Si⁻ only occurs at distances larger than approximately 10 µm from the root surface. Thus, we can distinguish distinct zones: the inner zone is composed of oxide encrusted root cells and their fragments. A thin intermediate zone may occur around some roots and comprises (hydr)oxides and organic matter. This can be distinguished from a silicate-dominated outer zone, which reflects the transition from the rhizosphere to the bulk soil. Full article

(This article belongs to the Special Issue Rhizosphere Processes)

► Show Figures

Graphical abstract

1 pages, 2091 KiB

Open AccessArticle

Relevance of Reactive Fe:S Ratios for Sulfur Impacts on Arsenic Uptake by Rice

Kristin Boye

Juan Lezama-Pacheco

and

Scott Fendorf

Soils 2017, 1(1), 1; https://doi.org/10.3390/soils1010001 - 09 Aug 2017

Cited by 4 | Viewed by 4561

Abstract

Human arsenic exposure from rice consumption is a global concern. Due to the vast areas of naturally contaminated soils in rice-producing regions, the only possibility for reducing hazardous exposure is to prevent As uptake and translocation to rice grain. Sulfur inhibits As mobility both in soil and plant, indicating that soil S content may be a primary factor controlling As uptake; indeed, gypsum (CaSO₄·H₂O) has been proposed as a potential amendment. Here, we investigated S controls on rice As uptake within two naturally contaminated soils (15.4 and 11.0 mg As per kg soil, respectively) from Cambodia, by adding gypsum at two levels (20 and 60 mg per kg soil). We found that although gypsum initially decreased As release to soil solution, the concentrations then increased compared to the control treatment. Further, As concentrations in rice biomass were generally insignificantly affected by the gypsum treatments and trended in opposite directions between the two soils. Single and multivariate statistical tests indicated that Fe exerted stronger control on As uptake in rice than S and that the initial ratio of reactive Fe to sulfate-S had an overriding impact on As uptake in rice. However, in the soil with higher inherent sulfate content (91 mg SO₄²⁻-S per kg soil) the additional S provided by gypsum appeared to increase the ability of the rice plant to prevent As translocation to grain. We conclude that S may contribute to regulating grain As concentrations, but that the effect is highly dependent on S:Fe(As) ratios. Thus, at modest amendment rates, gypsum has limited potential for minimizing As concentration in rice when applied to naturally contaminated soil, particularly if the reactive Fe(III) content is high. Full article

(This article belongs to the Special Issue Rhizosphere Processes)

► Show Figures

Journal Menu

Journal Browser

Special Issue "Rhizosphere Processes"

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (6 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI