The pea gene LH encodes ent-kaurene oxidase
The pea gene LH encodes ent-kaurene oxidase
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DOI：
10.1104/pp.103.032706
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发表时间：
2004-03-01
期刊：
影响因子：
7.4
通讯作者：
Reid, JB
中科院分区：
文献类型：
--
作者：
Davidson, SE;Smith, JJ;Reid, JB
分离了拟南芥GA 3基因的豌豆（Pisum sativum）同源物PsKO 1。它编码来自CYP 701 A亚家族的细胞色素P450，并且具有对映贝壳杉烯氧化酶（KO）活性，当在酵母（酿酒酵母）中表达时，在赤霉素（GA）生物合成途径中催化对映贝壳杉烯至对映贝壳杉烯酸的三步氧化。PsKO 1由LH基因编码，因为在三个独立的突变等位基因lh-1、lh-2和lh-3中，PsKO 1具有改变的序列，并且当在酵母中表达时，lh-1等位基因不能代谢对映贝壳杉烯。豌豆的lh突变体是GA缺陷的，并且具有降低的节间伸长和根生长。一个突变体（lh-2）也引起种子败育的大量增加。PsKO 1（LH）在所有检测的组织中表达，包括茎、根和种子，并且似乎是单拷贝基因。GA合成抑制剂，多效唑，突变体之间的敏感性的差异似乎是由于遗传病变的不同性质。这些差异也可以解释突变体之间的组织特异性差异。
The pea (Pisum sativum) homolog, PsKO1, of the Arabidopsis GA3 gene was isolated. It codes for a cytochrome P450 from the CYP701A subfamily and has ent-kaurene oxidase (KO) activity, catalyzing the three step oxidation of ent-kaurene to ent-kaurenoic acid in the gibberellin (GA) biosynthetic pathway when expressed in yeast (Saccharomyces cerevisiae). PsKO1 is encoded by the LH gene because in three independent mutant alleles, lh-1, lh-2, and lh-3, PsKO1 has altered sequence, and the lh-1 allele, when expressed in yeast, failed to metabolize ent-kaurene. The lh mutants of pea are GA deficient and have reduced internode elongation and root growth. One mutant (lh-2) also causes a large increase in seed abortion. PsKO1 (LH) is expressed in all tissues examined, including stems, roots, and seeds, and appears to be a single-copy gene. Differences in sensitivity to the GA synthesis inhibitor, paclobutrazol, between the mutants appear to result from the distinct nature of the genetic lesions. These differences may also explain the tissue-specific differences between the mutants.