Elucidation of the new signal transition pathway regarding auxin

阐明生长素的新信号转换途径

• 批准号: 09440263
• 负责人: NAGATA Toshiyuki
• 金额: $ 8.38万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440263/
• 关键词: auxin; signal trnasduction pathway; tobacco mesophyll protoplasts; cell cycle; dedifferentiation; cytokinin; cell division; DNA合成; プロトプラスト; 信号伝達; 馴化細胞; 転写因子; イオンチャンネル; 出芽コウボ; 2ハイブリッドシシステム; タンパク質キナーゼC

Although auxin was discovered as the first plant hormone, its molecular mechanism is least understood. Thus, this study was-attempted to elucidate signal transduction pathways downstream from auxin application. As we have identified auxin-regulated genes, parA, parB and parC, in our previous study, we further characterized auxin-responsive elements to these genes and subsequetnly showed that there are specific binding proteins to these elements, which are supposed to be involved in auxin-signalling pathways. In the meantime, we found that cytokinin, which is requested for the induction of cell division in tobacco mesophyll protoplasts, was found to play a critical role for the entry into cell cycle. It seems that cell cycle entry was triggered by cytokinin and the cell cycle progression was further facilitated by the gene products of auxin-regulated genes of parA, parB and parC, which encode different types of glutathione S-transferases. This is a completely new interpretation for the … More entry of tobacco mesophyll protoplasts into cell cycle progression, resulting in active cell division.On the other hand, regarding auxin-signalling pathways for tobacco BY-2 cell proliferation, we have identified an auxin-regualted gene, arcA, upon the addition of auxin to the auxin-starved BY-2 cells. In this case, involvement of β-subunit of KィイD1+ィエD1-ion channel proteins was proposed, but we have not gotten decisive conclusion for this pathway. However, we have identified another completely new pathway for auxin signalling. When we added culture filtrates of auxin-habituated 2B-13 cells to the auxin-starved BY-2 cells, we could see the induction of cell division in these cells. This was hot due to the low molecular weight plant hormones in the culture filtrates, but rather to higher molecular mass proteins. Further elucidation of the protein by a gel filtration using Sephadex G25 revealed that it was due to ca. 30 kDa protein. Though the nature of this protein has not been determined yet, it is certain that there is a new signalling pathway downstream from auxin application, as there has been reported no such pathways. Less

尽管生长素是第一个被发现的植物激素，但其分子机制却知之甚少。因此，本研究试图阐明生长素应用下游的信号转导途径。由于我们已经鉴定了生长素调节基因parA、parB和parC，在我们之前的研究中，我们进一步表征了这些基因的生长素响应元件，随后表明这些元件存在特异性结合蛋白，这些元件被认为参与生长素信号传导途径。与此同时，我们发现细胞分裂素（诱导烟草叶肉原生质体细胞分裂所需的细胞分裂素）在进入细胞周期中发挥着关键作用。似乎细胞周期进入是由细胞分裂素触发的，并且生长素调节基因parA、parB和parC的基因产物进一步促进了细胞周期进展，这些基因编码不同类型的谷胱甘肽S-转移酶。这是对烟草叶肉原生质体进入细胞周期进程，导致活跃的细胞分裂的全新解释。另一方面，关于烟草 BY-2 细胞增殖的生长素信号通路，我们在向生长素饥饿的 BY-2 细胞中添加生长素后，鉴定出了一个生长素调节基因 arcA。在这种情况下，有人提出KィイD1+ィエD1-离子通道蛋白的β-亚基参与其中，但我们尚未对该途径得出决定性的结论。然而，我们已经确定了另一种全新的生长素信号通路。当我们将生长素习惯的 2B-13 细胞的培养滤液添加到生长素饥饿的 BY-2 细胞中时，我们可以看到这些细胞中细胞分裂的诱导。这很热门是因为培养物滤液中含有低分子量植物激素，而不是更高分子量的蛋白质。通过使用 Sephadex G25 的凝胶过滤进一步阐明该蛋白质表明，它是由于大约。 30 kDa 蛋白质。尽管这种蛋白质的性质尚未确定，但可以肯定的是，生长素应用下游存在一条新的信号传导途径，因为据报道没有这样的途径。较少的

项目成果

Sano, T. et al.: "Phosphate as a limiting actor for the cell drvision of tobacco BY-2 cells"Plant Cell Physiol.. 40. 1-8 (1999)

Sano, T. 等人：“磷酸盐作为烟草 BY-2 细胞细胞驱动的限制因子”Plant Cell Physiol.. 40. 1-8 (1999)

Kumagai, F. et al.: "Putative involvement of a 49 kDa protein in microtubule assembly in vitro"Euro. J. Cell Biol.. 78. 109-116 (1999)

Kumagai, F. 等人：“49 kDa 蛋白质在体外微管组装中的推定参与”Euro。

Kitamiya, E. et al.: "Isolation of two genes that were induced upon the initiation of somatic embryogenesis on carrot hypocotyls by high concentration of 2,4-D."Plant Cell Reports.. (in press).

Kitamiya, E. 等人：“通过高浓度 2,4-D 在胡萝卜下胚轴上启动体细胞胚胎发生时诱导的两个基因的分离。”植物细胞报告..（正在出版）。

Hasezawa,S.et al.: "The role of microfilaments in the organization and orientation of microtubules during the cell cycle progression from M phase to G_1 phase in tobacco BY-2 cells." Protoplasma. 202. 105-114 (1998)

Hasezawa,S.et al.：“烟草 BY-2 细胞从 M 期到 G_1 期的细胞周期进展过程中，微丝在微管的组织和定向中的作用。”

Miyake,T.et al.: "Role of cytoskeletal components in the migration of nuclei during the cell cycle transition from G_1 phase to S phase of tobacco BY-2 cells." J.Plant Physiol.150. 528-536 (1997)

Miyake,T.et al.：“烟草 BY-2 细胞从 G_1 期到 S 期的细胞周期转变期间细胞骨架成分在细胞核迁移中的作用。”