Metagenomic Analysis\nto Assess the Impact of Plant\nGrowth-Promoting Rhizobacteria on Peanut (Arachis hypogaea L.) Crop Production and Soil Enzymes and Microbial Diversity

Peanut production could be increased through plant growth-promoting\nrhizobacteria (PGPR). In this regard, the present field research aimed\nat elucidating the impact of PGPR on peanut yield, soil enzyme activity,\nmicrobial diversity, and structure. Three PGPR strains (Bacillus velezensis, RI3; Bacillus\nvelezensis, SC6; Pseudomonas psychrophila, P10) were evaluated, along with Bradyrhizobium japonicum (BJ), taken as a control. PGPR increased seed yield by 8%, improving\nthe radiation use efficiency (4–14%). PGPR modified soil enzymes\n(fluorescein diacetate activity by 17% and dehydrogenase activity\nby 28%) and microbial abundance (12%). However, PGPR did not significantly\nalter microbial diversity; nonetheless, it modified the relative abundance\nof key phyla (Actinobacteria > Proteobacteria > Firmicutes)\nand genera\n(<i>Bacillus</i> > <i>Arthrobacter</i> > <i>Pseudomonas</i>). PGPRs modified the relative abundance of genes\nassociated with N-fixation and nitrification while increasing genes\nrelated to N-assimilation and N-availability. PGPR improved agronomic\ntraits without altering rhizosphere diversity.