RtNAC100 involved in the regulation of ROS, Na+ accumulation and induced salt-related PCD through MeJA signal pathways in recretohalophyte Reaumuria trigyna.

NAM, ATAF1/2, and CUC2 (NAC) proteins regulate plant responses to salt stress. However, the molecular mechanisms by which NAC proteins regulate salt-induced programmed cell death (PCD) are unclear. We identified 56 NAC genes, 35 of which had complete open reading frames with complete NAM domain, in the R. trigyna transcriptome. Salt stress and methyl jasmonate (MeJA) mediated PCD-induced leaf senescence in R. trigyna seedlings. Salt stress accelerated endogenous JA biosynthesis, upregulating RtNAC100 expression. This promoted salt-induced leaf senescence in R. trigyna by regulating RtRbohE and RtSAG12/20 and enhancing ROS accumulation. Transgenic assays showed that RtNAC100 overexpression aggravated salt-induced PCD in transgenic lines by promoting ROS and Na+ accumulation, ROS-Ca2+ hub activation, and PCD-related gene expression. Therefore, RtNAC100 induces PCD via the MeJA signaling pathway in R. trigyna under salt stress.