Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences; Beijing 100093, China; University of Chinese Academy of Sciences; Beijing 100049, China; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University; Beijing 100193, China.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University; Beijing 100193, China.
Mol Plant. 2022 Oct 3;15(10):1558-1574. doi: 10.1016/j.molp.2022.08.009. Epub 2022 Aug 31.
While crop yields have historically increased, drought resistance has become a major concern in the context of global climate change. The trade-off between crop yield and drought resistance is a common phenomenon; however, the underlying molecular modulators remain undetermined. Through genome-wide association study, we revealed that three non-synonymous variants in a drought-resistant allele of ZmSRO1d-R resulted in plasma membrane localization and enhanced mono-ADP-ribosyltransferase activity of ZmSRO1d toward ZmRBOHC, which increased reactive oxygen species (ROS) levels in guard cells and promoted stomatal closure. ZmSRO1d-R enhanced plant drought resilience and protected grain yields under drought conditions, but it led to yield drag under favorable conditions. In contrast, loss-of-function mutants of ZmRBOHC showed remarkably increased yields under well-watered conditions, whereas they showed compromised drought resistance. Interestingly, by analyzing 189 teosinte accessions, we found that the ZmSRO1d-R allele was present in teosinte but was selected against during maize domestication and modern breeding. Collectively, our work suggests that the allele frequency reduction of ZmSRO1d-R in breeding programs may have compromised maize drought resistance while increased yields. Therefore, introduction of the ZmSRO1d-R allele into modern maize cultivars would contribute to food security under drought stress caused by global climate change.
虽然作物产量在历史上有所增加，但在全球气候变化的背景下，抗旱性已成为一个主要关注点。作物产量和抗旱性之间的权衡是一个常见的现象；然而，潜在的分子调节剂仍未确定。通过全基因组关联研究，我们揭示了 ZmSRO1d-R 抗旱等位基因中的三个非同义变异导致 ZmSRO1d 向 ZmRBOHC 的质膜定位和单 ADP-核糖基转移酶活性增强，从而增加保卫细胞中的活性氧 (ROS) 水平并促进气孔关闭。ZmSRO1d-R 增强了植物的抗旱能力，并在干旱条件下保护了谷物产量，但在有利条件下导致产量下降。相比之下，ZmRBOHC 的功能丧失突变体在充分浇水条件下表现出显著增加的产量，而在抗旱性方面表现出受损。有趣的是，通过分析 189 个玉米近缘种，我们发现 ZmSRO1d-R 等位基因存在于玉米近缘种中，但在玉米驯化和现代育种过程中被选择淘汰。总的来说，我们的工作表明，在育种计划中，ZmSRO1d-R 等位基因频率的降低可能削弱了玉米的抗旱性，同时提高了产量。因此，将 ZmSRO1d-R 等位基因引入现代玉米品种将有助于应对全球气候变化导致的干旱胁迫下的粮食安全。
