The sorghum SbMPK3-SbNAC074 module involved in salt tolerance

Plant NAC transcription factors (TFs) are essential genes that modulate plant responses to abiotic stress. In this study, we identified a novel NAC TF, SbNAC074, in sorghum, which exhibits a response to salt stress. Overexpression of SbNAC074 in tobacco significantly enhanced the salt tolerance of transgenic plants. Measurements of stress-related physiological indicators revealed that the overexpression of SbNAC074 led to a reduction in the accumulation of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), while simultaneously increasing the activities of key enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Furthermore, we identified SbMPK3, the interacting protein of SbNAC074, and established that SbMPK3 can phosphorylate SbNAC074. Consequently, this study elucidates the function of SbNAC074 and identifies the SbMPK3-SbNAC074 regulatory pathway, thereby providing new insights into the mechanisms underlying salt stress responses in sorghum.