Epigenetic and transcriptomic features of stress memory during salt-stress priming in arabidopsis

Plants can develop a 'stress memory' that enables them to respond more effectively upon re-exposure to stress. It has been reported that priming plays a role in the formation of stress memory. In this study, Arabidopsis plants were primed with 50 mM NaCl for 24 h. Following a recovery period, they were subjected to subsequent salt stress, and it was observed that the primed plants were significantly less affected compared to the non-primed group. Furthermore, genes associated with epigenetic memory influencing stress response were investigated through RNA sequencing and ChIP analyses following the priming and salt stress applications. These analyses identified alpha-linolenic acid metabolism, diterpenoid biogenesis, and plant hormone signal transduction pathways as the most significantly altered pathways related with stress memory. Additionally, ChIP-qPCR analyses were performed on key genes within these pathways. RNA-seq analysis and changes in H3K27me3 and H3K4me histone marks were correlated, specifically in OPR3, AOC1, and LOX3 genes that enabled us to obtain strong evidence regarding their effects on plant stress memory. The findings are expected to guide future studies in manipulating the identified candidate genes involved in epigenetic stress memory, thereby contributing to a deeper understanding of the molecular mechanisms underlying these processes.