Elucidation of the regulation mechanism of gene expression in the totipotency of plant cells

植物细胞全能性基因表达调控机制的阐明

• 批准号: 05404004
• 负责人: NAGATA Toshiyuki
• 金额: $ 22.27万
• 依托单位: University of Tokyo, Graduate School of Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05404004/
• 关键词: totipotency; dedifferentiation; redifferentiation; auxin; cytokinin; transcriptional regulation; signal transduction chain; embryogenesis; Gタンパク質; 遺伝子発現

Though the totipotency of plant cells is said to be the most characteristic features of plant and it is used as the main means of plant biotechnology, its molecular mechanism is least elucidated. In this study, the totipotency has been studied at the three phases ; the dedifferentiation of differentiated somatic cells, the maintenance of these cells that regain cell division activity and the redifferentiation of these cells to whole plants. Since two plant hormones of auxin and cytokinin have been shown to be most influential in all of these three processes, the molecular mode of these two plant hormones has been intensively studied in respective three stages. Regarding the dedifferentiation process, we have isolated three auxin-regulated genes, parA,parB and parC,from the early stage of cultured tobacco mesophyll protoplasts. Thus we tried to elucidate the transcriptional regulation of these genes. Our efforts identified auxin-responsive elements in these genes and in particular, in t … More he parB promoter. Furthermore, we have identified a protein that binds to one of auxin-responsive element, which is classified as one of b-ZIPs. We have also identified a cytokinin-regulated gene as the first case in this category. Though the characterization of this cytokinin-regulated gene is currently under study, it seems to belong to arabinogalactan-related proteins. Subsequently we have identified arcA gene as an auxin-regulated gene in the actively dividing tobacco BY-2 cells. arcA has been found to be a homologue of receptor for activated C-Kinase. Furthermore, a protein that could have protein-protein interaction with this arcA protein has been indentified by means of the yeast two-hybrid system. This protein is a homologue of beta-subunit of K^+-channel. Thus it became certain that there is a novel signal transduction chain down-stream of auxin application, resulting in the cell division of cultured cells.On the other hand, we have identified two auxin-regulated genes in the early stage of embryogenesis of carrot epidermis tissues. One is found to be a homologue of parA,while the other is found to be a homologue of low-molecular weight heat shock proteins.Thus in this study we have identified several molecules that are involved in different phases of totipotency. Though full details of totipotency still remains to be elucidated, general features of totipotency has been shown in this study. Less

植物细胞的全能性被认为是植物最显著的特征，也是植物生物技术研究的主要手段，但其分子机制目前还不清楚。在这项研究中，全能性已在三个阶段进行了研究：分化的体细胞的去分化，这些细胞恢复细胞分裂活性的维持和这些细胞再分化为完整的植物。由于生长素和细胞分裂素这两种植物激素在这三个过程中的作用最大，因此这两种植物激素的分子模式在三个阶段都得到了深入的研究。关于脱分化过程，我们从培养的烟草叶肉原生质体的早期阶段分离了三个生长素调控的基因，帕拉，parB和parC。因此，我们试图阐明这些基因的转录调控。我们的努力确定了这些基因中的生长素反应元件，特别是在 ...更多信息 他是parB发起人。此外，我们已经确定了一种蛋白质，结合到生长素的反应元件，这是被归类为b-ZIPs之一。我们还确定了细胞分裂素调节基因作为这一类的第一例。虽然目前正在研究这种细胞分裂素调控基因的特征，但它似乎属于阿拉伯半乳聚糖相关蛋白。随后，我们已经确定arcA基因作为生长素调控的基因在活跃分裂的烟草BY-2细胞。arcA是活化C激酶受体的同源物。利用酵母双杂交系统，进一步鉴定了与该arcA蛋白具有蛋白质-蛋白质相互作用的蛋白质。该蛋白质是K^+通道β亚基的同源物。因此，可以肯定的是，在生长素的应用下游存在一条新的信号传导链，导致培养细胞的细胞分裂。另一方面，我们在胡萝卜表皮组织的胚胎发生早期鉴定了两个生长素调控的基因。其中一个是帕拉的同源物，而另一个是低分子量热休克蛋白的同源物，因此在这项研究中，我们已经确定了几个分子参与不同阶段的全能性。虽然全能性的全部细节仍有待阐明，但全能性的一般特征已在本研究中显示。少

项目成果

Nagata, T., Ishida, S., Hasezawa, S.and Takahashi Y.: "Genes involved in the dedifferentiation of plant cells." Internatl. J.Develop. Biol.38. 321-327 (1994)

Nagata, T.、Ishida, S.、Hasezawa, S.和 Takahashi Y.：“参与植物细胞去分化的基因。”

Sakai, T., Takahashi, Y.and Nagata, T.: "Analysis of the promoter of the auxin-inducible gene, parC,of tobacco." Plant Cell Physiol.37. 906-913 (1996)

Sakai, T.、Takahashi, Y. 和 Nagata, T.：“烟草生长素诱导基因 parC 启动子的分析”。

Ishida, S., Takahashi, Y.and Nagata, T.: "Isolation of cDNA of an auxin-regulated gene encoding a G protein beta-subunit-like protein from tobacco BY-2 cells." Proc.Natl.Acad.Sci.USA. 90. 11152-11156 (1993)

Ishida, S.、Takahashi, Y. 和 Nagata, T.：“从烟草 BY-2 细胞中分离编码 G 蛋白 β 亚基样蛋白的生长素调节基因的 cDNA。”

Isida S.et al.: "The mode of expression and promoter analysis of the arcA gene,an auxin-regulated gene in tobacco BY-2 cells." Plant Cell Physiol.37. 439-448 (1996)

Isida S.et al.：“烟草 BY-2 细胞中生长素调节基因 arcA 基因的表达模式和启动子分析。”

Kusaba,M.et al.: "A multiple-stimuli-responsive as-1-related element of parA gene confers responsiveness to cadmium but not copper." Plant Physiol.111. 1161-1167 (1996)

Kusaba,M.等人：“parA 基因的多重刺激响应 as-1 相关元件赋予对镉的响应性，但对铜没有响应性。”