P-271 - Unveiling the hidden language: Exploring the dynamics between Maize plant and plant growth promoting rhizobacteria Priestia aryabhattai AB211

Rhizosphere dynamics are tightly regulated by root-secreted metabolites, known as root exudates (REs), which trigger the initial signaling cascade for symbiotic interactions with plant growth-promoting rhizobacteria (PGPR). In this study, we aimed to identify key components of maize REs and explore the molecular communication between Priestia aryabhattai AB211, a potent PGPR, and maize. LC-MS analysis of maize REs at three different seedling stages revealed various organic and phenolic acids, sugars, amino acids, and hormones. RNA-seq analysis of AB211 at two growth stages, treated with crude REs, showed significant expression changes in 979 genes during the late exponential phase and 309 genes during the stationary phase (∣log2FC∣>1.5). Notable upregulation of genes for methyl-accepting chemotaxis proteins (MCP) and flagellar motility (fliY, flgG) suggested that REs are chemoattractive. Additionally, differential expression of genes involved in carbohydrate and amino acid metabolism indicated that REs serve as a nutrient source for bacterial survival and association. The upregulation of spo0A and spoVG genes pointed to biofilm formation, facilitating AB211's adherence to root surfaces. These results were consistent when AB211 was treated with methyl jasmonate, a key chemoattractive component of REs. Identifying the compounds involved in plant-PGPR communication holds promise for advancing sustainable agriculture by optimizing rhizosphere interactions.