Department of Biology and Centers for Molecular Signaling and Redox Biology and Medicine, Wake Forest University, Winston-Salem, NC 27109, USA.
Department of Biology and Centers for Molecular Signaling and Redox Biology and Medicine, Wake Forest University, Winston-Salem, NC 27109, USA
Development. 2020 Apr 27;147(8):dev185819. doi: 10.1242/dev.185819.
Reactive oxygen species (ROS) are signaling molecules produced by tissue-specific respiratory burst oxidase homolog (RBOH) enzymes to drive development. In , ROS produced by RBOHC was previously reported to drive root hair elongation. We identified a specific role for one ROS, HO, in driving root hair initiation and demonstrated that localized synthesis of flavonol antioxidants control the level of HO and root hair formation. Root hairs form from trichoblast cells that express RBOHC and have elevated HO compared with adjacent atrichoblast cells that do not form root hairs. The flavonol-deficient mutant has elevated ROS in trichoblasts and elevated frequency of root hair formation compared with the wild type. The increases in ROS and root hairs in are reversed by genetic or chemical complementation. Auxin-induced root hair initiation and ROS accumulation were reduced in an mutant and increased in , consistent with flavonols modulating ROS and auxin transport. These results support a model in which localized synthesis of RBOHC and flavonol antioxidants establish patterns of ROS accumulation that drive root hair formation.
活性氧（ROS）是由组织特异性呼吸爆发氧化酶同源物（RBOH）酶产生的信号分子，用于驱动发育。在，先前报道 RBOHC 产生的 ROS 驱动根毛伸长。我们确定了一种特定的 ROS，HO，在驱动根毛起始中的作用，并表明类黄酮抗氧化剂的局部合成控制 HO 的水平和根毛形成。根毛从表达 RBOHC 的生毛细胞形成，与不形成根毛的相邻无毛细胞相比，HO 水平升高。与野生型相比，类黄酮缺乏的突变体中生毛细胞中的 ROS 升高，根毛形成的频率升高。与野生型相比，突变体中 ROS 和根毛的增加可以通过遗传或化学互补来逆转。在突变体中，生长素诱导的根毛起始和 ROS 积累减少，而在突变体中增加，这与类黄酮调节 ROS 和生长素运输一致。这些结果支持了一个模型，即 RBOHC 和类黄酮抗氧化剂的局部合成建立了 ROS 积累的模式，从而驱动根毛形成。
