Genomic features of Agrobacterium divergnes Azo12 and wheat responses to salinity stress

Salinity is a major abiotic stress limiting wheat productivity worldwide. This study investigated the genomic features of Agrobacterium divergens Azo12, a strain previously identified as a promising plant growth-promoting rhizobacterium (PGPR) supporting wheat growth under saline conditions, and explored transcriptomic responses of wheat ( Triticum aestivum L.) seedlings to salinity following bacterial inoculation. Whole-genome sequencing identified genes associated with osmotic stress adaptation and nutrient metabolism, including pathways related to glycine betaine, proline, and trehalose metabolism. Genomic analysis further indicated the absence of key virulence determinants, supporting the non-phytopathogenic character of the strain. Wheat seedlings were inoculated with Azo12 and exposed to salt stress under controlled conditions, followed by transcriptome profiling to compare gene expression between inoculated and non-inoculated plants. Differentially expressed genes and transcripts were functionally annotated, and selected targets were assessed using RT-qPCR. Transcriptome analysis identified a limited number of genes responsive to inoculation under salinity stress, including genes associated with methyltransferase activity, defense responses, photoperiod regulation, and phosphate transport. RT-qPCR analysis showed expression trends generally consistent with the RNA-seq results and indicated a moderate positive correlation between platforms (Spearman’s ρ = 0.5, p = 0.391), although differences between control and treatment conditions were not statistically significant in the validation assays. Overall, the findings suggest that Azo12 inoculation may be associated with modest transcriptional modulation in wheat under salt stress and provide a set of candidate genes for further investigation of PGPR-related stress adaptation processes.