P-229 - Toward understanding rhizomicrobiomes-driven epigenetic modifications in tomatoes

As holobionts, plants live together with diverse microorganisms in nature. These interactions can have either beneficial or detrimental effects on plants and play an essential role in plant resilience by modulating phenotypic plasticity. Recent evidence suggests that rhizomicrobiomes can induce epigenetic modifications in plant genomes. However, the long-term stability of epigenetic changes in crops induced by rhizomicrobiomes remains unclear. To address it, we investigated phenotypic changes in tomatoes (cv. Micro-Tom) grown in soils treated with distinct microbiota collected from various regions. Among these, we selected two soil microbiomes that either promoted tomato growth or accelerated fruit maturation. Tomatoes exposed to these microbiomes were grown under the identical conditions for three generations and the growth-promoting effect persisted. Through 16S rDNA-based metagenomic analysis, we identified compositional differences in rhizomicrobiomes between the two soils. Additionally, exposure to specific microbiota caused transcriptional changes of genes related to DNA methylation, including SlCMT2, SlDRM6, and SlDML4. Additionally, a whole-genome bisulfite sequencing analysis was conducted to evaluate the persistence of epigenetic changes in the tomato genome. Our study provides new insights into the role of rhizomicrobiomes in epigenetic modifications and their potential impact on phenotypic plasticity.