Biosynthesis of cytokinins
Biosynthesis of cytokinins
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DOI：
10.1007/s10265-003-0095-5
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发表时间：
2003-06-01
影响因子：
2.8
通讯作者：
Kakimoto, T
中科院分区：
文献类型：
--
作者：
Kakimoto, T
细胞分裂素是具有类异戊二烯侧链的腺嘌呤衍生物，在植物发育中发挥重要作用。最近已经鉴定出催化细胞分裂素生物合成的第一步和限速步骤的植物异戊烯基转移酶。与催化异戊烯基部分从二甲基烯丙基二磷酸 (DMAPP) 转移到腺苷 5'-单磷酸 (AMP) 的 N-6 位的细菌酶不同，植物酶催化异戊烯基部分从 DMAPP 优先转移到 ATP 和 ADP。异戊烯基侧链被羟基化，形成玉米素型细胞分裂素。还提出了另一种途径，其中羟基化侧链直接添加到腺嘌呤部分的 N-6 位。
Cytokinins are adenine derivatives with an isoprenoid side chain and play an essential role in plant development. Plant isopentenyltransferases that catalyze the first and rate-limiting steps of cytokinin biosynthesis have recently been identified. Unlike bacterial enzymes, which catalyze the transfer of the isopentenyl moiety from dimethylallyldiphosphate (DMAPP) to the N-6 position of adenosine 5'-monophosphate (AMP), plant enzymes catalyze the transfer of the isopentenyl moiety from DMAPP preferentially to ATP and to ADP. The isopentenylated side chain is hydroxylated to form zeatin-type cytokinins. An alternative pathway, in which a hydroxylated side chain is directly added to the N-6 position of the adenine moiety, has also been suggested.