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Long-Term Irrigation Affects the Dynamics and Activity of the Wheat Rhizosphere Microbiome
The Inland Pacific Northwest (IPNW) encompasses 1. 6 million cropland hectares and is a major wheat-producing area in the western United States. The climate throughout the region is semi-arid, making the availability of water a significant challenge for IPNW agriculture. Much attention has been give...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5871930/ https://www.ncbi.nlm.nih.gov/pubmed/29619036 http://dx.doi.org/10.3389/fpls.2018.00345 |
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author | Mavrodi, Dmitri V. Mavrodi, Olga V. Elbourne, Liam D. H. Tetu, Sasha Bonsall, Robert F. Parejko, James Yang, Mingming Paulsen, Ian T. Weller, David M. Thomashow, Linda S. |
author_facet | Mavrodi, Dmitri V. Mavrodi, Olga V. Elbourne, Liam D. H. Tetu, Sasha Bonsall, Robert F. Parejko, James Yang, Mingming Paulsen, Ian T. Weller, David M. Thomashow, Linda S. |
author_sort | Mavrodi, Dmitri V. |
collection | PubMed |
description | The Inland Pacific Northwest (IPNW) encompasses 1. 6 million cropland hectares and is a major wheat-producing area in the western United States. The climate throughout the region is semi-arid, making the availability of water a significant challenge for IPNW agriculture. Much attention has been given to uncovering the effects of water stress on the physiology of wheat and the dynamics of its soilborne diseases. In contrast, the impact of soil moisture on the establishment and activity of microbial communities in the rhizosphere of dryland wheat remains poorly understood. We addressed this gap by conducting a three-year field study involving wheat grown in adjacent irrigated and dryland (rainfed) plots established in Lind, Washington State. We used deep amplicon sequencing of the V4 region of the 16S rRNA to characterize the responses of the wheat rhizosphere microbiome to overhead irrigation. We also characterized the population dynamics and activity of indigenous Phz(+) rhizobacteria that produce the antibiotic phenazine-1-carboxylic acid (PCA) and contribute to the natural suppression of soilborne pathogens of wheat. Results of the study revealed that irrigation affected the Phz(+) rhizobacteria adversely, which was evident from the significantly reduced plant colonization frequency, population size and levels of PCA in the field. The observed differences between irrigated and dryland plots were reproducible and amplified over the course of the study, thus identifying soil moisture as a critical abiotic factor that influences the dynamics, and activity of indigenous Phz(+) communities. The three seasons of irrigation had a slight effect on the overall diversity within the rhizosphere microbiome but led to significant differences in the relative abundances of specific OTUs. In particular, irrigation differentially affected multiple groups of Bacteroidetes and Proteobacteria, including taxa with known plant growth-promoting activity. Analysis of environmental variables revealed that the separation between irrigated and dryland treatments was due to changes in the water potential (Ψ(m)) and pH. In contrast, the temporal changes in the composition of the rhizosphere microbiome correlated with temperature and precipitation. In summary, our long-term study provides insights into how the availability of water in a semi-arid agroecosystem shapes the belowground wheat microbiome. |
format | Online Article Text |
id | pubmed-5871930 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-58719302018-04-04 Long-Term Irrigation Affects the Dynamics and Activity of the Wheat Rhizosphere Microbiome Mavrodi, Dmitri V. Mavrodi, Olga V. Elbourne, Liam D. H. Tetu, Sasha Bonsall, Robert F. Parejko, James Yang, Mingming Paulsen, Ian T. Weller, David M. Thomashow, Linda S. Front Plant Sci Plant Science The Inland Pacific Northwest (IPNW) encompasses 1. 6 million cropland hectares and is a major wheat-producing area in the western United States. The climate throughout the region is semi-arid, making the availability of water a significant challenge for IPNW agriculture. Much attention has been given to uncovering the effects of water stress on the physiology of wheat and the dynamics of its soilborne diseases. In contrast, the impact of soil moisture on the establishment and activity of microbial communities in the rhizosphere of dryland wheat remains poorly understood. We addressed this gap by conducting a three-year field study involving wheat grown in adjacent irrigated and dryland (rainfed) plots established in Lind, Washington State. We used deep amplicon sequencing of the V4 region of the 16S rRNA to characterize the responses of the wheat rhizosphere microbiome to overhead irrigation. We also characterized the population dynamics and activity of indigenous Phz(+) rhizobacteria that produce the antibiotic phenazine-1-carboxylic acid (PCA) and contribute to the natural suppression of soilborne pathogens of wheat. Results of the study revealed that irrigation affected the Phz(+) rhizobacteria adversely, which was evident from the significantly reduced plant colonization frequency, population size and levels of PCA in the field. The observed differences between irrigated and dryland plots were reproducible and amplified over the course of the study, thus identifying soil moisture as a critical abiotic factor that influences the dynamics, and activity of indigenous Phz(+) communities. The three seasons of irrigation had a slight effect on the overall diversity within the rhizosphere microbiome but led to significant differences in the relative abundances of specific OTUs. In particular, irrigation differentially affected multiple groups of Bacteroidetes and Proteobacteria, including taxa with known plant growth-promoting activity. Analysis of environmental variables revealed that the separation between irrigated and dryland treatments was due to changes in the water potential (Ψ(m)) and pH. In contrast, the temporal changes in the composition of the rhizosphere microbiome correlated with temperature and precipitation. In summary, our long-term study provides insights into how the availability of water in a semi-arid agroecosystem shapes the belowground wheat microbiome. Frontiers Media S.A. 2018-03-21 /pmc/articles/PMC5871930/ /pubmed/29619036 http://dx.doi.org/10.3389/fpls.2018.00345 Text en Copyright © 2018 Mavrodi, Mavrodi, Elbourne, Tetu, Bonsall, Parejko, Yang, Paulsen, Weller and Thomashow. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Plant Science Mavrodi, Dmitri V. Mavrodi, Olga V. Elbourne, Liam D. H. Tetu, Sasha Bonsall, Robert F. Parejko, James Yang, Mingming Paulsen, Ian T. Weller, David M. Thomashow, Linda S. Long-Term Irrigation Affects the Dynamics and Activity of the Wheat Rhizosphere Microbiome |
title | Long-Term Irrigation Affects the Dynamics and Activity of the Wheat Rhizosphere Microbiome |
title_full | Long-Term Irrigation Affects the Dynamics and Activity of the Wheat Rhizosphere Microbiome |
title_fullStr | Long-Term Irrigation Affects the Dynamics and Activity of the Wheat Rhizosphere Microbiome |
title_full_unstemmed | Long-Term Irrigation Affects the Dynamics and Activity of the Wheat Rhizosphere Microbiome |
title_short | Long-Term Irrigation Affects the Dynamics and Activity of the Wheat Rhizosphere Microbiome |
title_sort | long-term irrigation affects the dynamics and activity of the wheat rhizosphere microbiome |
topic | Plant Science |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5871930/ https://www.ncbi.nlm.nih.gov/pubmed/29619036 http://dx.doi.org/10.3389/fpls.2018.00345 |
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