The OsNAC41-RoLe1-OsAGAP module promotes root development and drought tolerance in upland rice.

Abstract

Drought is a major environmental stress limiting crop yields worldwide. Upland rice (Oryza sativa) has evolved complex genetic mechanisms to adjust to drought stress. However, few genetic variants have been identified that mediate drought resistance in upland rice, and little is known about the evolution of this trait during domestication. Here, using a genome-wide association study in rice, we identified ROOT LENGTH 1 (RoLe1) controlling root length and drought resistance. We demonstrate that a G-to-T polymorphism in the RoLe1 promoter increases binding of the transcription factor OsNAC41 to activate its transcription. We also show that RoLe1 interacts with and interferes with the function of OsAGAP, an ARF-GTPase activating protein involved in auxin-dependent root development, to modulate root development. Furthermore, RoLe1 enhanced crop yield by increasing the seed setting rate under moderate drought conditions. Genomic evolution analysis showed that a newly arisen favorable allelic variant, proRoLe1^-526T, originated from Region I (Midwest Asia) and was retained in upland rice during domestication. Our findings propose a OsNAC41-RoLe1-OsAGAP module, providing promising genetic targets for molecular breeding of drought-resistant varieties in rice.