Functions and regulatory framework of ZmNST3 in maize under lodging and drought stress.

The growth and development of maize are negatively affected by various abiotic stresses including drought, high salinity, extreme temperature, and strong wind. Therefore, it is important to understand the molecular mechanisms underlying abiotic stress resistance in maize. In the present work, we identified that a novel NAC transcriptional factor,ZmNST3, enhances maize lodging resistance and drought stress tolerance. ChIP-Seq and expression of target genes analysis showed thatZmNST3could directly regulate the expression of genes related to cell wall biosynthesis which could subsequently enhance lodging resistance. Furthermore, we also demonstrated thatZmNST3affected the expression of genes related to the synthesis of antioxidant enzyme secondary metabolites that could enhance drought resistance. More importantly, we are the first to report thatZmNST3directly binds to the promoters ofCESA5andDynamin-Related Proteins2A(DRP2A) and activates the expression of genes related to secondary cell wall cellulose biosynthesis. Additionally, we revealed thatZmNST3directly binds to the promoters of GST/GlnRS and activates genes which could enhance the production of antioxidant enzymes in vivo. Overall, our work contributes to a comprehensive understanding of the regulatory network ofZmNST3in regulating maize lodging and drought stress resistance.