Discrepancies in rhizobacterial assembly caused by glyphosate application and herbicide-tolerant soybean Co-expressing GAT and EPSPS

Abstract

There are concerns that the innovation of genetically modified herbicide-tolerant (GMHT) plants, as well as the application of herbicide to such GMHT plants, could have an impact on ecological interactions and unintentionally harm non-targeted organisms. Consequently, we intend to use full-length 16 S rDNA amplicon sequencing to examine changes in the bacterial community in the rhizosphere of GMHT soybean (Z106) harboring 5-enolpyruvylshikimate-3-phosphate synthase and Glyphosate N-acetyltransferase genes and GMHT soybean treated with glyphosate (Z106G). Glyphosate application significantly impacted bacterial alpha diversity (species richness, and Shannon diversity). Permutational multivariate analysis of variance of beta diversity demonstrated that soil compartments and growth stages had a substantial impact on soybean rhizobacterial communities (soil compartments, growth stages, P = 0.001). Community composition revealed that Z106G soils were abundant in Taibaiella and Arthrobacter pascens at maturity, while Chryseobacterium joostei and Stenotrophomonas maltophilia predominated in Z106 soils during flowering. Nitrogen-fixing and phosphate-solubilizing microbes were found in higher proportions in the rhizosphere than in bulk soil, with Sinorhizobium being more abundant in Z106 and Bacillus and Stenotrophomonas being more prevalent in Z106G rhizosphere soils. Collectively, our findings suggest glyphosate application and glyphosate-tolerant soybean as potential regulators of soybean rhizobacterial composition.

Keywords: Full-length 16 S rDNA; Glyphosate application; Glyphosate-tolerant soybean; Nitrogen fixation; Rhizobacterial composition.