OsbZIP65 enhances cold tolerance in rice by regulating ROS scavenging and carbohydrate metabolism

Here, we identified the Group S bZIP transcription factor OsbZIP65 as a positive regulator of rice chilling tolerance. OsbZIP65 was rapidly induced by chilling and functioned as a nuclear transcriptional activator.

Its overexpression enhanced survival and alleviated membrane injury, whereas knockout increased chilling sensitivity. OsbZIP65 bound G-box-containing promoter regions of OsGSTU6, OsGR3, and OsAGPS1, activating the former first two and repressing the latter, with these effects enhanced by chilling. Accordingly, OsbZIP65 promoted antioxidant capacity and soluble sugar accumulation while reducing reactive oxygen species and starch levels.