Molecular basis for cytokinin biosynthesis
Molecular basis for cytokinin biosynthesis
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DOI：
10.1016/j.phytochem.2009.02.007
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发表时间：
2009-03-01
期刊：
影响因子：
3.8
通讯作者：
Sakakibara, Hitoshi
中科院分区：
文献类型：
--
作者：
Kamada-Nobusada, Tome;Sakakibara, Hitoshi
细胞分裂素（Cytokinins，CKs）是一类在植物生长发育中起重要调节作用的植物激素。对参与CK代谢的酶和相应基因的鉴定使我们能够了解植物如何合成CK并将CK活性调节到最佳水平。实现这些目标的一个主要成就是确定了CK生物合成途径中第一种酶的基因，即磷酸腺苷-异戊烯基转移酶（IPT）。在拟南芥和根癌农杆菌中，不仅通过酶表征而且通过分子结构方法进行IPT的详细分析。这些研究揭示了农杆菌来源的IPT的分子基础，用于有效地生物合成转玉米素，促进宿主植物中的肿瘤发生。CK研究的另一个里程碑是CYP 735 A被鉴定为将iP-核苷酸转化为tZ-核苷酸的酶。此外，CK激活酶，催化一种新的激活途径，是CK研究的一个显着的最新成就。总的来说，这些进展揭示了CK生物合成的整个代谢方案的复杂性。(C)2009爱思唯尔有限公司保留所有权利。
Cytokinins (CKs) are a group of phytohormones that play a crucial role in the regulation of plant growth and development. Identification of the enzymes and the corresponding genes that are involved in CK metabolism allowed us to understand how plants synthesize CKs and adjust CK activity to optimal levels. A major accomplishment toward these goals was the identification of genes for the first enzyme in the CK biosynthetic pathway, adenosine phosphate-isopentenyltransferase (IPT). in Arabidopsis thaliana and Agrobacterium tumefaciens, detailed analyses of IPTs were conducted through not only enzymatic characterization but also molecular structural approaches. These studies revealed the molecular basis for the Agrobacterium-origin of IPT used for the efficient biosynthesis of trans-zeatin that promotes tumorigenesis in host plants. Another landmark in CK research was the identification of CYP735A as an enzyme that converts iP-nucleotide to tZ-nucleotide. Furthermore, the identification of a CK-activating enzyme, LOG, which catalyzes a novel activation pathway, is a remarkable recent achievement in CK research. Collectively, these advances have revealed the complexity of the entire metabolic scheme for CK biosynthesis. (C) 2009 Elsevier Ltd. All rights reserved.