The role of OsBRI1 and its homologous genes, OsBRL1 and OsBRL3, in rice
The role of OsBRI1 and its homologous genes, OsBRL1 and OsBRL3, in rice
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DOI：
10.1104/pp.105.072330
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发表时间：
2006-02-01
期刊：
影响因子：
7.4
通讯作者：
Matsuoka, M
中科院分区：
文献类型：
--
作者：
Nakamura, A;Fujioka, S;Matsuoka, M
自从首次鉴定了水稻油菜素内酯（BR）不敏感突变体d 61的两个等位基因，这两个等位基因在拟南芥（Arabidopsis thaliana）油菜素内酯不敏感基因1（BRI 1）中也有缺陷，我们已经分离出水稻BRI 1基因OsBRI 1的另外8个等位基因，包括无效突变。最严重的突变体，d 61 -4，表现出严重的矮化和扭曲的叶片，虽然图案的形成和分化是正常的。这种严重的芽表型主要是由细胞伸长的缺陷和细胞命运确定后细胞分裂的干扰引起的。与其严重的芽表型相反，d 61 -4突变体具有轻度的根表型。与此同时，水稻中活性BR Castasterone的积累在芽中高达30倍，而在根中仅高出1.5倍。OsBRI 1、OsBRL 1和OsBRL 3的同源基因在根中高表达，但在茎中弱表达，并且它们在d 61 -4中的表达高于野生型。基于这些观察，我们得出结论，OsBRI 1是不是必不可少的图案形成或器官的启动，但参与器官发育，通过控制细胞分裂和伸长。此外，OsBRL 1和OsBRL 3至少部分参与根中的BR感知。
Since first identifying two alleles of a rice ( Oryza sativa) brassinosteroid (BR)-insensitive mutant, d61, that were also defective in an orthologous gene in Arabidopsis ( Arabidopsis thaliana) BRASSINOSTEROID INSENSITIVE1 (BRI1), we have isolated eight additional alleles, including null mutations, of the rice BRI1 gene OsBRI1. The most severe mutant, d61-4, exhibited severe dwarfism and twisted leaves, although pattern formation and differentiation were normal. This severe shoot phenotype was caused mainly by a defect in cell elongation and the disturbance of cell division after the determination of cell fate. In contrast to its severe shoot phenotype, the d61-4 mutant had a mild root phenotype. Concomitantly, the accumulation of castasterone, the active BR in rice, was up to 30-fold greater in the shoots, while only 1.5-fold greater in the roots. The homologous genes for OsBRI1, OsBRL1 and OsBRL3, were highly expressed in roots but weakly expressed in shoots, and their expression was higher in d61-4 than in the wild type. Based on these observations, we conclude that OsBRI1 is not essential for pattern formation or organ initiation, but is involved in organ development through controlling cell division and elongation. In addition, OsBRL1 and OsBRL3 are at least partly involved in BR perception in the roots.