A brassinosteroid-insensitive mutant in Arabidopsis thaliana exhibits multiple defects in growth and development
A brassinosteroid-insensitive mutant in Arabidopsis thaliana exhibits multiple defects in growth and development
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DOI：
10.1104/pp.111.3.671
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发表时间：
1996-07-01
期刊：
影响因子：
7.4
通讯作者：
McMorris, TC
中科院分区：
文献类型：
--
作者：
Clouse, SD;Langford, M;McMorris, TC
油菜素类化合物是一类广泛分布的植物化合物，可以调节细胞的伸长和分裂，但对这些植物生长调节剂的作用机制知之甚少。为了研究油菜素内酯作为影响植物生长发育的信号，我们在拟南芥中鉴定了一个油菜素内酯不敏感突变体。亨利。生态型哥伦比亚。该突变体命名为BRI1，在下胚轴伸长和初生根抑制试验中对油菜素类固醇没有反应，但它对生长素、细胞分裂素、乙烯、脱落酸和赤霉素保持敏感。BRI1突变体在发育途径上表现出多种无法通过油菜素类固醇处理的缺陷，包括严重矮化的身材；深绿色的加厚叶片；雄性不育；顶端优势减弱；以及深色生长的幼苗脱黄化。遗传分析表明，BRI1表型是由单个基因的隐性突变引起的，该基因具有多效性，从位于IV染色体底部的切割的、扩增的、多态的序列标记DHS1定位到1.6厘米器官。BRI1基因突变对发育的多重和戏剧性的影响表明，BRI1基因可能在油菜素类固醇的感知或信号转导中发挥关键作用。
Brassinosteroids are widely distributed plant compounds that modulate cell elongation and division, but little is known about the mechanism of action of these plant growth regulators. To investigate brassinosteroids as signals influencing plant growth and development, we identified a brassinosteroid-insensitive mutant in Arabidopsis thaliana (L.) Henyh. ecotype Columbia. The mutant, termed bri1, did not respond to brassinosteroids in hypocotyl elongation and primary root inhibition assays, but it did retain sensitivity to auxins, cytokinins, ethylene, abscisic acid, and gibberellins. The bri1 mutant showed multiple deficiencies in developmental pathways that could not be rescued by brassinosteroid treatment, including a severely dwarfed stature; dark green, thickened leaves; male sterility; reduced apical dominance; and de-etiolation of dark-grown seedlings. Genetic analysis suggests that the Bri1 phenotype is caused by a recessive mutation in a single gene with pleiotropic effects that maps 1.6 centimorgans from the cleaved, amplified, polymorphic sequence marker DHS1 on the bottom of chromosome IV. The multiple and dramatic effects of mutation of the BRI1 locus on development suggests that the BRI1 gene may play a critical role in brassinosteroid perception or signal transduction.