Journal Article

Plant Nutrient Resource Use Strategies Shape Active Rhizosphere Microbiota Through Root Exudation

Achouak, Wafa, Haichar, Feth el Zahar, Dubost, Audrey, Heulin, Thierry, Ortet, Philippe, Guillemet, Martin, Barakat, Mohamed, Guyonnet, Julien P., Simon, Laurent

2018

Overview

Plant strategies for soil nutrient uptake have the potential to strongly influence plant-microbiota interactions, due to the competition between plants and microorganisms for soil nutrient acquisition and/or conservation. In the present study, we investigate whether these plant strategies could influence rhizosphere microbial activities root exudation, and contribute to the microbiota diversification of active bacterial communities colonizing the root-adhering soil (RAS) and inhabiting the root tissues. We applied a DNA-based stable isotope probing (DNA-SIP) approach to six grass species distributed along a gradient of plant nutrient resource strategies, from conservative species, characterized by low nitrogen (N) uptake, a long lifespans and low root exudation level, to exploitative species, characterized by high rates of photosynthesis, rapid rates of N uptake and high root exudation level. We analyzed their (i) associated microbiota composition involved in root exudate assimilation and soil organic matter (SOM) degradation by 16S-rRNA-based metabarcoding. (ii) We determine the impact of root exudation level on microbial activities (denitrification and respiration) by gas chromatography. Measurement of microbial activities revealed an increase in denitrification and respiration activities for microbial communities colonizing the RAS of exploitative species. This increase of microbial activities results probably from a higher exudation rate and more diverse metabolites by exploitative plant species. Furthermore, our results demonstrate that plant nutrient resource strategies have a role in shaping active microbiota. We present evidence demonstrating that plant nutrient use strategies shape active microbiota involved in root exudate assimilation and SOM degradation root exudation.

• Publisher: Frontiers Media SA,Frontiers,Frontiers Media S.A
• Subject: active bacterial community / Assimilation / Biodiversity and Ecology / Biological assimilation / Carbon / Degradation / Denitrification / Deoxyribonucleic acid / DNA / Environmental Sciences / Exudation / Flowers & plants / Gas chromatography / Grasses / Labeling / Life Sciences / Metabolites / microbial activities / Microbial activity / Microbiota / Microorganisms / Nitrogen / Nutrient uptake / Organic matter / Photosynthesis / Plant growth / plant nutrient use strategies / Plant Science / Plant species / Plant tissues / Plants (botany) / Respiration / Rhizosphere / Rhizosphere microorganisms / Roots / rRNA 16S / Soil degradation / Soil ecology / Soil microorganisms / Soil nutrients / Soil organic matter / Species / Stable isotopes / Taxonomy