Facing chilling, kinase-transcription factors relay cold tolerance signals

Abstract

Rice (Oryza sativa L.), native to tropical regions, is highly vulnerable to low temperatures, limiting its geographical range and posing a substantial threat to global rice production. Our understanding of the molecular basis for cold tolerance in rice remains incomplete. A recent study identified OsERF52, an AP2/ERF transcription factor, as a new upstream regulator of OsCBFs, through a mutant screening approach. Under cold stress, phosphorylation of OsERF52 at Ser261 by OsSAPK9 not only stabilizes the protein but also enhances its interaction with IPA1 and OsICE1/OsbHLH002, leading to an increase in OsCBF transcription and enhanced chilling tolerance. Importantly, plants with a base-edited OsERF52^S261D-3HA allele show improved cold resistance without yield loss under normal conditions. After chilling stress at the booting stage, these plants had significantly higher seed-setting rates than controls. These findings establish OsERF52 as a key regulator of OsCBFs, highlight a novel kinase-transcription factor complex that modulates cold response, and provide valuable genetic resources for breeding cold-tolerant rice varieties.