The sax1 mutation defines a new locus involved in the brassinosteroid biosynthesis pathway in Arabidopsis thaliana
The sax1 mutation defines a new locus involved in the brassinosteroid biosynthesis pathway in Arabidopsis thaliana
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DOI：
10.1046/j.1365-313x.1999.00455.x
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发表时间：
1999-05-01
期刊：
影响因子：
7.2
通讯作者：
Barbier-Brygoo, H
中科院分区：
文献类型：
--
作者：
Ephritikhine, G;Pagant, S;Barbier-Brygoo, H
在这个问题上，我们描述了一个矮秆突变体拟南芥，纱丽，这是影响油菜素类固醇的生物合成。这种主要缺陷导致纱丽植物激素敏感性的改变，其特征在于根伸长对脱落酸和生长素的敏感性以及下胚轴生长对赤霉素和乙烯的不敏感性（Ephritikhine等人，18，303-314）。在本文中，我们报告的萨克斯管的进一步表征？突变体，旨在鉴定油菜素类固醇生物合成途径中的突变步骤。用该途径的各种中间体进行的拯救实验表明，sax 1突变改变了催化3 β-羟基δ（5，6）6前体氧化和异构化为3-氧代δ（4，5）类固醇的非常早期的步骤。突变的映射，突变体的生理特性和救援实验表明，纱丽定义一个新的基因座的油菜素类固醇生物合成途径。SAX 1蛋白参与光照和黑暗条件下幼苗依赖油菜素类固醇的生长。
In this issue we described a dwarf mutant in Arabidopsis thaliana, sari, which is affected in brassinosteroid biosynthesis. This primary defect is responsible for alterations in hormone sensitivity of sari plants characterized by the hypersensitivity of root elongation to abscisic acid and auxin and the insensitivity of hypocotyl growth to gibberellins and ethylene (Ephritikhine ef al., 1999; Plant J. 18, 303-314). In this paper, we report the further characterization of the sax? mutant aimed at identification of the mutated step in the brassinosteroid biosynthesis pathway. Rescue experiments with various intermediates of the pathway showed that the sax1 mutation alters a very early step catalyzing the oxidation and isomerization of 3 beta-hydroxyl,Delta(5,6) 6 precursors to 3-oxo,Delta(4,5) steroids. The mapping of the mutation, the physiological properties of the mutant and the rescue experiments indicate that sari defines a new locus in the brassinosteroid biosynthesis pathway. The SAX1 protein is involved in brassinosteroid-dependent growth of seedlings in both light and dark conditions.