Frontiers Science Center for Molecular Design Breeding, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
Frontiers Science Center for Molecular Design Breeding, Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
Mol Plant. 2024 Oct 7;17(10):1573-1593. doi: 10.1016/j.molp.2024.09.002. Epub 2024 Sep 2.
Drought is a major environmental stress limiting crop yields worldwide. Upland rice (Oryza sativa) has evolved complex genetic mechanisms for adaptative growth under drought stress. However, few genetic variants that mediate drought resistance in upland rice have been identified, and little is known about the evolution of this trait during rice domestication. In this study, using a genome-wide association study we identified ROOT LENGTH 1 (RoLe1) that controls rice root length and drought resistance. We found that a G-to-T polymorphism in the RoLe1 promoter causes increased binding of the transcription factor OsNAC41 and thereby enhanced expression of RoLe1. We further showed that RoLe1 interacts with OsAGAP, an ARF-GTPase activating protein involved in auxin-dependent root development, and interferes with its function to modulate root development. Interestingly, RoLe1 could enhance crop yield by increasing the seed-setting rate under moderate drought conditions. Genomic evolutionary analysis revealed that a newly arisen favorable allelic variant, proRoLe1, originated from the midwest Asia and was retained in upland rice during domestication. Collectively, our study identifies an OsNAC41-RoLe1-OsAGAP module that promotes upland rice root development and drought resistance, providing promising genetic targets for molecular breeding of drought-resistant rice varieties.
干旱是限制全球作物产量的主要环境胁迫因素。旱稻（Oryza sativa）已经进化出复杂的遗传机制，以适应干旱胁迫下的生长。然而，已经确定的介导旱稻抗旱性的少数遗传变异体，以及在水稻驯化过程中这一性状的进化知之甚少。在这项研究中，我们使用全基因组关联研究鉴定了控制水稻根长和抗旱性的 ROOT LENGTH 1（RoLe1）。我们发现 RoLe1 启动子中的 G 到 T 多态性导致转录因子 OsNAC41 的结合增加，从而增强了 RoLe1 的表达。我们进一步表明，RoLe1 与 OsAGAP 相互作用，OsAGAP 是一种参与生长素依赖性根发育的 ARF-GTPase 激活蛋白，并干扰其功能以调节根发育。有趣的是，RoLe1 可以通过增加中度干旱条件下的结实率来提高作物产量。基因组进化分析表明，一个新出现的有利等位变体 proRoLe1 起源于中亚，并在驯化过程中保留在旱稻中。总的来说，我们的研究确定了一个 OsNAC41-RoLe1-OsAGAP 模块，该模块促进旱稻根的发育和抗旱性，为抗旱性水稻品种的分子育种提供了有前景的遗传靶标。
