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并形成特征性表皮膀胱细胞（EBC）的植物，这对于耐盐性非常重要。然而，迄今为止，关于这些结构的形成的信息还很少。为了确定它们形成的遗传基础，我们应用甲磺酸乙酯诱变，获得了两个 EBC ( rebc ) 水平降低和叶绿体异常的突变体。计算机减法实验表明，rebc表型是由REBC突变引起的，REBC 编码定位于细胞核和叶绿体的 WD40 蛋白。系统发育和转化体分析表明，REBC 蛋白与 TTG1（一种参与毛状体形成的 WD40 蛋白）不同。此外，rebc突变体在非生物胁迫下表现出对其茎尖的损害，这表明 EBC 可以保护茎尖免受此类胁迫。这些发现将有助于阐明 EBC 形成和功能的机制。