Research of Cytokinin Signaling

细胞分裂素信号研究

• 批准号: 09440267
• 负责人: TATSUO Kakimoto
• 金额: $ 6.98万
• 依托单位: Osaka University
• 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-09440267/
• 关键词: cytokinin; Signal transduction; CKI1; CKI2; CKH1; CKH2; histidine kinase; 受容体; シロイヌナズナ; MSH; シュート; カルス; アクティベーションタギング; 再生

This research was aimed at a better understanding of the cytokinin signaling pathway. For this purpose we have isolated Arabidopsis mutants that exhibit altered responses to cytokinins. We used either a strong transcriptional enhancer(4x35s enhancer) or a chemical as a mutagen. We previously isolated the cki1 and cki2 mutants, which exhibit constitutive cytokinin responses, among transformants with the strong transcriptional enhancer. In this study we have isolated the causal gene for cki2 mutant, and shown that the gene codes for a histidine kinase. The typical feature of the CK12 product is that it is predicted to reside at the cytoplasm, while all other histidine kinases in Arabidopsis are predicted to reside at the palsmamembrane. In the cki2 mutant, the 4x 35S enhancer was inserted in the coding region of the CK12 gene. Transcription of the CK12 gene initiated within the enhancer, probably resulting in the production of a product lacking part of its Nterminal region. We have also isolated the causal genes for cytokinin hyper and less-sensitive mutants, ckh1 and ckl1 respectively, which were isolated from an EMS mutagenized population. The CKH1 gene code for a product with similarity to TAFs, which are members of the transcriptional initiation complex. The CKL1 gene coded for a histidine kinase, emphasizing the importance of the two-component systems in cytokinin perception.

本研究旨在更好地了解细胞分裂素的信号通路。为此，我们分离了对细胞分裂素反应发生改变的拟南芥突变体。我们使用了强转录增强剂(4x35s增强子)或化学物质作为诱变剂。我们以前从具有强转录增强子的转化子中分离出了具有结构性细胞分裂素反应的ck i1和ck i2突变体。在这项研究中，我们分离了CKI2突变体的致病基因，并证明该基因编码组氨酸激酶。CK12产物的典型特征是它被预测位于细胞质中，而拟南芥中的所有其他组氨酸激酶被预测位于掌膜中。在CKI2突变体中，4×35S增强子插入到CK12基因的编码区。CK12基因的转录在增强子内启动，可能导致产物的产生缺少其N端的部分区域。我们还分离了细胞分裂素高敏感型和低敏感型突变体的致病基因，它们分别是从EMS诱变群体中分离出来的。CKH1基因编码的产物与TAFs相似，TAFs是转录起始复合体的成员。CKL1基因编码一种组氨酸激酶，强调了双组分系统在细胞分裂素感知中的重要性。

项目成果

Kakimoto,Tatsuo: "Genes involved in cytokinin signaling" J.Plant.Res.111. 261-265 (1998)

Kakimoto, Tatsuo：“参与细胞分裂素信号传导的基因”J.Plant.Res.111。

Kakimoto T.: "Cytokinin signaling"Curr. Opin. Plant Biol.. 1. 349-403 (1998)

Kakimoto T.：“细胞分裂素信号传导”Curr。

Nakamura A.: "Biochemical characterization of a putative sytokinin-responsive His-kinase, CKI1, from Arabidopsis thaliana"Biosci. Biotechnol. Biochem.. 63. 1627-1630 (1999)

Nakamura A.：“来自拟南芥的假定的细胞分裂素反应性组氨酸激酶 CKI1 的生化特征”Biosci。

Kakimoto T.: "Genes involved in cytokinin signal transduction"J. Plant Res., Plant Res.. 111. 261-265 (1998)

Kakimoto T.：“参与细胞分裂素信号转导的基因”J.

Nakamura, A., Kakimoto, T., Imamura, A., Suzuki, T.,: "Ueguchi, C. and Mizuno, T. Biochemical characterization of a putative cytokinin-responsive His-kinase, CKI1, from Arabidopsis thaliana."Biosci. Biotechnol. Biochem.. 63. 1627-1630 (1999)

Nakamura, A.、Kakimoto, T.、Imamura, A.、Suzuki, T.：“Ueguchi, C. 和 Mizuno, T. 来自拟南芥的假定细胞分裂素响应型组氨酸激酶 CKI1 的生化特征。”