Abstract

Drought stress severely restricts plant growth and crop productivity. Although numerous transcription factors have been linked to drought responses, the regulatory networks underlying drought tolerance in rice remain incompletely understood. Here, through a CRISPR/Cas9-based genetic screen of a rice mutant population, we identified a mutant with decreased drought tolerance, osdt2. OsDT2 encodes a CCCH-type zinc-finger protein and its overexpression confers strong drought resistance. We demonstrate that OsDT2 physically interacts with the bZIP transcription factor OsbZIP66, and they synergistically activate drought-responsive genes, such as LATE EMBRYOGENESIS ABUNDANT 3 (OsLEA3), to enhance drought tolerance. Furthermore, the nuclear factor Y subunit C4 (OsNF-YC4) interacts with both OsDT2 and OsbZIP66, coordinating their recruitment to the promoter of OsLEA3. Remarkably, the OsDT2 function is conserved across cereals, including wheat and maize, and the tripartite DT2-bZIP66-NF-YC4 module is functionally conserved in mediating drought responses in both rice and Arabidopsis. Collectively, our study reveals a novel, evolutionarily conserved transcriptional regulatory module that fine-tunes drought-responsive gene expression and provides potential targets for engineering drought-resilient crops.