ZmWAK3 overexpression enhances cold tolerance via coordinated improvement of antioxidant defense and photosynthesis.

key messageThe ZmNAC100-ZmWAK3 transcriptional module enhances maize cold tolerance by coordinately enhancing antioxidant defense and improving photosynthetic efficiency. Low temperature is a major abiotic stress that constrains agricultural productivity by severely inhibiting crop growth and development, leading to substantial yield losses. As a chilling-sensitive crop, maize is particularly vulnerable to cold stress. Cold conditions induce excessive accumulation of reactive oxygen species in plants, disrupting photosynthetic performance, compromising antioxidant defense systems, and disturbing cellular ion homeostasis. In this study, we demonstrated that the maize wall-associated receptor kinase gene ZmWAK3 positively regulates the response to low temperature. Using overexpression and mutant lines, we found that ZmWAK3 overexpression enhanced chilling tolerance by improving ROS scavenging capacity and photosynthetic efficiency. In contrast, zmwak3 mutant exhibited a cold-sensitive phenotype. At the molecular level, combined evidence from yeast one-hybrid, dual-luciferase reporter, and chromatin immunoprecipitation assays confirmed that the transcription factor ZmNAC100 directly binds to the ZmWAK3 promoter and activates its transcription. Furthermore, silencing ZmNAC100 in maize not only reduced cold tolerance but also downregulated ZmWAK3 expression. Collectively, our results elucidate a low-temperature response pathway in maize mediated by the ZmNAC100-ZmWAK3 module, which enhances cold tolerance by increasing antioxidant enzyme activities, alleviating oxidative damage, and improving photosynthetic performance.