Overexpression of ZmNF-YC13 Confers ER Stress Tolerance in Maize

Excessive accumulation of unfolded or misfolded proteins in the lumen of the endoplasmic reticulum (ER) can trigger ER stress. Although regulation of this stress response in plants is an important and effective means of mitigating the damage caused by stress, the associated genes and mechanisms in maize remain largely unknown. In this study, we identified the ER stress-responsive gene ZmNF-YC13 , which encodes a protein localized in the nuclei and cytoplasm of maize cells. The overexpression of ZmNF-YC13 in maize and Arabidopsis was found to confer plant ER stress tolerance, and gene expression analyses revealed that the overexpression of this gene upregulates the expression of genes involved in protein folding and the ER-associated degradation (ERAD) system, including ERdj , BiP, and E3 ubiquitin ligase . Moreover, we established that ZmNF-YC13 activates the promoters of the chaperone genes ZmERdj and ZmBiP in protoplasts, which function in the elimination of unfolded and misfolded proteins in the ER. Based on our findings, we propose that ZmNF-YC13 positively regulates the ER stress response in maize by controlling chaperone genes, and we believe that these results could provide valuable information for further maize resistance breeding.