Abstract
Low temperature severely impairs rice growth and productivity. Although the OsEIN2-OsEIL1/2 signaling pathway has been reported to negatively regulate chilling tolerance via OsICE1 in rice, the full regulatory network remains unclear. Here, we demonstrate that OsEIL1/2 negatively regulates chilling tolerance by promoting OsMYB30 expression and enhancing reactive oxygen species (ROS) accumulation. RT-qPCR, yeast one-hybrid assay, EMSA and ChIP-qPCR assay revealed that OsEIL1/2 directly target the promoter of OsMYB30 and activate its expression. Furthermore, we found that OsMYB30 modulates ROS homeostasis by regulating ascorbate peroxidase (OsAPX3) and peroxidase (OsPRX12//41/136) expression under chilling stress. Importantly, association analysis revealed a superior haplotype of OsMYB30 (Hap1), prevalent in japonica rice, which is linked to enhanced seedling survival under chilling stress. Taken together, our findings elucidate a novel mechanism of OsEIN2-OsEIL1/2 signal negatively regulates rice chilling tolerance through OsMYB30-mediated ROS homeostasis, Moreover, this study highlights the potential of Hap1 for breeding chilling-tolerant rice varieties.