Metagenomic Insight into the Community Structure and Functional Genes in the Sunflower Rhizosphere Microbiome

Abstract

The rhizosphere’s microbial communities consist of a diverse set of microorganisms that can be beneficial to plants. These beneficial microorganisms are key determinants of plant productivity and health. In this study, we used shotgun metagenomics to explore and characterize the microbiome of the sunflower rhizosphere and bulk soil. The rhizosphere shared features with the bulk soil with dominant phyla such as Actinobacteria, Proteobacteria, Acidobacteria, Bacteroidetes, Planctomycetes, and Verrucomicrobia. There was no significant difference in the alpha diversity of the sunflower rhizosphere and bulk soils, though diversity was lower in the rhizosphere, suggesting a selection of microorganisms by sunflower rhizosphere to the bulk soil community. The genes present in the rhizosphere with their corresponding proteins as observed in our study conferred potential plant-beneficial properties such as siderophore production, nitrogen fixation, phosphate solubilizing, 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Furthermore, other genes such as exopolysaccharides-producing, high-temperature stress response, and heat and cold shock response genes, which help withstand environmental stresses were also identified more in the rhizosphere. Of note from our study is the gene phenazine biosynthesis protein, which confers biocontrol. With the current indiscriminate use of pesticides that are considered harmful to the ecosystem, these potential functional genes can be further exploited and used as a biotechnological application for sustainable agriculture.