The diverse functional genes of maize rhizosphere microbiota assessed using shotgun metagenomics

Background The geographical diversification in chemical, biological and physical properties of plant biospheres instigates heterogenicity in the proliferation of important soil microbiome. Controlling functions and structure of plant rhizosphere from a better understanding and prediction of a plant's immediate environment will help assess plant-microbe interplay, improve the productivity of plant ecosystems and improve plant response to adverse soil conditions. Here we characterized functional genes of the microbial community of maize rhizosphere using a culture-independent method. Results Our metadata showed microbial genes involved in nitrogen fixation, phosphate solubilization, quorum sensing molecules, trehalose, siderophore production, phenazine biosynthesis protein, daunorubicin resistance, acetoin, 1-aminocyclopropane-1-carboxylate deaminase, 4-hydroxybenzoate, disease control and stress-reducing genes (superoxidase dismutase, catalase, peroxidase, etc.). beta-Diversity showed that there is a highly significant difference between most of the genes mined from rhizosphere soil samples and surrounding soils. Conclusions The high relative abundance of stress-reducing genes mined from this study showed that the sampling sites harbor not only important plant-beneficial organisms but also a hotspot for developing bio-fertilizers. Nevertheless, since most of these organisms are unculturable, mapping cultivation strategies for their growth could make them readily available as bio-inoculants and possible biotechnological applications in the future.