Overexpression of maize transcription factor ZmNF-YC14 positively regulates drought and salt stress responses in Arabidopsis thaliana.

Maize (Zea mays L.) is a food crop with the largest planted area globally and one of the highest total yields worldwide. However, in recent years, deteriorating climate, increasing scarcity of freshwater resources, and rising land salinity have caused drought and salinity stress to be the two major factors that restrict crop growth, development, and yield, significantly affecting crop production and ecological sustainability. Nuclear factor Ys (NF-Ys) are an important class of transcription factors (TFs); however, their roles in plant stress tolerance responses and the underlying molecular mechanisms remain largely unknown. In this study, we conducted a bioinformatic analysis of 17 members of the maize NF-YC family and examined the ZmNF-YC14 gene through multiple sequence alignment among different species and HFD_NF-YC-like functional domains. Reverse transcription quantitative PCR (RT-qPCR) results indicated that ZmNF-YC14 exhibited the highest expression levels in maize leaves and was positively expressed under both drought and salt stress treatments. Western blot analysis revealed a distinct band at 27.68 kDa. Analyses of Escherichia coli BL21 and yeast strains confirmed that ZmNF-YC14 plays a biological role in enhancing tolerance to salt and drought stress. Arabidopsis plants overexpressing ZmNF-YC14 demonstrated reduced levels of hydrogen peroxide, superoxide anion, and malondialdehyde while exhibiting increased peroxidase, catalase, and superoxide dismutase activities after drought and salt stress treatments. This effect was attributed to the reciprocal relationship between ZmNF-YC14 and its downstream target gene ZmCONSTANS-LIKE16. Therefore, ZmNF-YC14 and ZmCONSTANS-LIKE16 may be essential for the response to abiotic stresses such as drought and salt stress in maize. They play a crucial role in the development of new germplasm, cultivation of new maize varieties, addressing the 'necklace' problem in crop breeding, and ensuring national food security.