The impact of OsASR5 on rice microbiome: Implications for nutrient cycling and stress response

Plant-microorganism interactions contribute to plant health by enhancing nutrient acquisition. The transcription factor OsASR5 regulates detoxification gene expression under aluminum stress in rice and is implicated as a positive regulator of responses to iron and phosphorus deficiency. Given its role in nutrient regulation, we investigated whether OsASR5 influences the assembly of the rice microbiome. In this study, we characterized the bacteria communities associated with the leaves and roots of OsASR5-RNAi rice plants compared to wild-type Oryza sativa cv. Nipponbare. Notably, OsASR5-RNAi plants showed altered bacterial beta diversity compared with wild type. The bacterial composition of OsASR5-RNAi plants differed in both organs, with decreased Desulfobacteriota and increased in Acidobacteria abundance in leaves. At the genus level, Methylobacterium, a known plant growth promoter, was less prevalent in leaves, while Magnetospirillum, associated with iron cycling, was less abundant in roots. Conversely, several bacteria were more abundant in OsASR5-RNAi plants, including Aneurinibacillus, Anaeromyxobacter, and Methylobacter, which are associated with nitrogen cycling and phosphorus solubilization. Additionally, Geobacter and Geothrix, both known for their role in metal reduction, particularly iron, were more abundant in OsASR5-RNAi plants. These suggest that OsASR5 affects plant-microbe interactions, potentially influencing nutrient cycling and plant stress responses through microbiome modulation.