Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 308-1, Nonoichi, Ishikawa, 921-8836, Japan.
Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, 606-8502, Japan.
Commun Biol. 2020 Sep 17;3(1):513. doi: 10.1038/s42003-020-01249-w.
Halophytes are plants that grow in high-salt environments and form characteristic epidermal bladder cells (EBCs) that are important for saline tolerance. To date, however, little has been revealed about the formation of these structures. To determine the genetic basis for their formation, we applied ethylmethanesulfonate mutagenesis and obtained two mutants with reduced levels of EBCs (rebc) and abnormal chloroplasts. In silico subtraction experiments revealed that the rebc phenotype was caused by mutation of REBC, which encodes a WD40 protein that localizes to the nucleus and chloroplasts. Phylogenetic and transformant analyses revealed that the REBC protein differs from TTG1, a WD40 protein involved in trichome formation. Furthermore, rebc mutants displayed damage to their shoot apices under abiotic stress, suggesting that EBCs may protect the shoot apex from such stress. These findings will help clarify the mechanisms underlying EBC formation and function.
盐生植物是在高盐环境中生长的植物，它们形成特征性的表皮囊泡细胞（EBCs），这对于耐盐性很重要。然而，目前对于这些结构的形成知之甚少。为了确定其形成的遗传基础，我们应用乙基甲磺酸诱变剂获得了两个 EBC 水平降低（rebc）和叶绿体异常的突变体。在计算机减法实验中发现，rebc 表型是由 REBC 的突变引起的，REBC 编码一种 WD40 蛋白，该蛋白定位于细胞核和叶绿体。系统发育和转化体分析表明，REBC 蛋白与参与毛状体形成的 WD40 蛋白 TTG1 不同。此外，rebc 突变体在非生物胁迫下表现出分生组织顶端的损伤，这表明 EBC 可能保护分生组织顶端免受这种胁迫。这些发现将有助于阐明 EBC 形成和功能的机制。
