Assembly and variation of root-associated microbiota of rice during their vegetative growth phase with and without lindane pollutant

Abstract

Soil-derived microbiota associated with plant roots are conducive to plant growth and stress resistance. However, the spatio-temporal dynamics of microbiota in response to organochlorine pollution during the unstable vegetative growth phase of rice is not well understood. In this study, we focused on the rice (Oryza sativa L.) microbiota across the bulk soil, rhizosphere and endosphere compartments during the vegetative growth phase in two different soils with and without lindane pollutant. The results showed that the factors of growth time, soil types and rhizo-compartments had significant influence on the microbial communities of rice, while lindane mostly stimulated the construction of endosphere microbiota at the vegetative phase. Active rice root-soil-microbe interactions induced an inhibition effect on lindane removal at the later vegetative growth phase in rice-growth-dependent anaerobic condition, likely due to the root oxygen loss and microbial mediated co-occurring competitive electron-consuming redox processes in soils. Each rhizo-compartment owned distinct microbial communities, and therefore, presented specific ecologically functional categories, while the moderate functional differences were also affected by plants species and residual pollution stress. This work revealed the underground micro-ecological process of microbiota and especially their potential linkage to the natural attenuation of residual organochlorine such as lindane.