Molecular Mechanism of Intercellular Signaling in Plant Organogenesis

本项目旨在利用拟南芥的几个突变体来阐明植物器官发生中的细胞间信号转导机制。本课题的主要研究结果如下：（1）鉴定并克隆了促进根毛细胞分化的正调控因子CPC。CPC编码一个小的myb蛋白，并发现在非毛细胞中表达。这强烈表明CPC蛋白移动到邻近的毛细胞。(2)HY5基因在光形态建成、细胞伸长、细胞分裂和叶绿体发育中起作用。我们克隆了HY5，发现它编码一个bZIP蛋白，并与其他光形态建成调控蛋白COP1和DET1相关。(3)我们克隆了一个花基因FIL，发现它编码一个含有锌指和HMG相关结构域的蛋白。FIL在叶片和花器官的远轴侧组织中表达。转基因植株表明，FIL在决定侧生器官远轴侧的位置上起作用。(4)我们发现了一个分生组织结构异常的突变体L12，它有两个突变。其中一个基因L12a被发现编码HSP90相关蛋白。

This project aimed to clarify intercellular signaling mechanism in plant organogenesis using several mutants of Arabidopsis. Major results obtained in the 3-year project are : (1) We identified and cloned a positive regulator, CPC, promoting differentiation of the root hair cells. CPC encodes a small myb protein, and found to be expressed in non-hair cells. It is strongly suggested that CPC protein moves to the neighboring hair cells. (2) HY5 gene was shown to have a role in photomorphogenesis, cell elongation, cell division, and chloroplast development. We cloned HY5 and found it encodes a bZIP protein, and associates with other photomorphogenesis regulatory proteins COP1 and DET1. (3) We cloned a flower gene, FIL, and found it encodes a protein with a zinc-finger and a HMG-related domains. FIL was expressed at the abaxial side tissues of leaves and of floral organs. Transgenic plants showed FIL has a role in determination of the abaxial side of lateral organs. (4) We identified a mutant with aberrant structure in meristems, L12, has two mutations. One gene, L12a, was found to encode a HSP90-related protein.