Ke Wensheng, Zhao Yidi, Liu Yunjie, Yang Qun, Chen Zhaoyan, Guo Jinquan, Wang Ruizhao, Xu Weiya, Du Dejie, Zhang Yufeng, Guo Weilong, Liu Jie, Xin Mingming, Hu Zhaorong, Peng Huiru, Yao Yingyin, Sun Qixin, Chang Zhijian, Ni Zhongfu, Xing Jiewen
Frontiers Science Center for Molecular Design Breeding (MOE), Key Laboratory of Crop Heterosis and Utilization (MOE), China Agricultural University, Beijing 100193, China.
The Shanxi Province Key Laboratory of Crop Genetics and Gene Improvement, College of Agronomy, Shanxi Agricultural University, Taiyuan, Shanxi 030031, China.
Plant Cell. 2025 Jul 1;37(7). doi: 10.1093/plcell/koaf174.
Root hairs serve as a crucial interface between plants and soil, facilitating efficient water and nutrient uptake. However, the genetic mechanisms governing root hair traits in wheat (Triticum aestivum L.) remain largely unexplored. In this study, we identified the awn inhibitor gene B1 as an important regulator of root hair length (RHL) through map-based cloning and reported a preferred allele for an ideotype of the root system in wheat. B1 suppressed RHL by decreasing reactive oxygen species (ROS) buildup, whereas a defective B1 resulted in increased RHL and enhanced nutrient uptake efficiency in wheat. In addition, B1 directly repressed the expression of ROOT HAIR DEFECTIVE SIX-LIKE2 (TaRSL2) and ROOT HAIR DEFECTIVE SIX-LIKE4 (TaRSL4), encoding 2 positive regulators of RHL, thereby activating TaRBOHH9 expression and accelerating ROS production. Furthermore, B1 interacted with TaHDA6, reducing histone H3K9ac and H3K14ac modifications and inhibiting the expression of downstream genes. Our work not only unveils the pivotal role of B1-mediated epigenetic regulation of RHL and nutrient uptake but also presents editable molecular targets for breeding eco-friendly sustainable crops.
根毛是植物与土壤之间的关键界面，有助于高效吸收水分和养分。然而，控制小麦（Triticum aestivum L.）根毛性状的遗传机制在很大程度上仍未得到探索。在本研究中，我们通过图位克隆鉴定出芒抑制基因B1是根毛长度（RHL）的重要调节因子，并报道了小麦根系理想型的一个优选等位基因。B1通过减少活性氧（ROS）积累来抑制RHL，而有缺陷的B1则导致小麦RHL增加和养分吸收效率提高。此外，B1直接抑制编码RHL的2个正向调节因子的根毛缺陷六样蛋白2（TaRSL2）和根毛缺陷六样蛋白4（TaRSL4）的表达，从而激活TaRBOHH9表达并加速ROS产生。此外，B1与TaHDA6相互作用，减少组蛋白H3K9ac和H3K14ac修饰并抑制下游基因的表达。我们的工作不仅揭示了B1介导的RHL表观遗传调控和养分吸收的关键作用，还为培育生态友好型可持续作物提供了可编辑的分子靶点。
