Overexpression of constitutive differential growth 1 gene, which encodes a RLCKVII-subfamily protein kinase, causes abnormal differential and elongation growth after organ differentiation in arabidopsis
Overexpression of constitutive differential growth 1 gene, which encodes a RLCKVII-subfamily protein kinase, causes abnormal differential and elongation growth after organ differentiation in arabidopsis
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DOI：
10.1104/pp.104.046805
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发表时间：
2004-10-01
期刊：
影响因子：
7.4
通讯作者：
Yamamoto, KT
中科院分区：
文献类型：
--
作者：
Muto, H;Yabe, N;Yamamoto, KT
为了更好地了解植物器官分化生长的遗传调控，利用激活标签技术分离到一个显性半矮秆突变体，组成型分化生长1-显性（cdg 1-D）。cdg 1-D表现出多效性，包括矮化、叶上向性增强以及下胚轴、花序茎和叶柄的扭曲或螺旋生长。在光照条件下，cdg 1-D的下胚轴比野生型的下胚轴长。该表型由编码RLCKVII亚家族受体样胞质激酶的CDG 1基因的激活标签引起。当用高浓度的芸苔素处理时，光生长的野生型幼苗表现出长的下胚轴和在cdg 1-D幼苗中观察到的强的叶上向性。用油菜素内酯（BR）生物合成的特异性抑制剂芸苔素唑处理cdg 1-D，不能挽救突变体表型。在cdg 1-D植物中，BR生物合成和phyB激活标记的SUPPOR 1基因表达的组成型光形态发生和矮化分别被抑制和诱导，这表明突变体中BR信号的组成型激活。CDG 1在测试的野生型的所有器官中以非常低的水平表达。我们分离了两个独立的cdg 1-D基因内抑制子。然而，它们表现出正常的形态，并以与野生型相似的方式对BR作出反应。综上所述，CDG 1基因在野生型中的过表达可能会干扰BR的信号转导，但不是BR信号转导的必要因素。
To better understand genetic regulation of differential growth of plant organs, a dominant and semidwarf mutant, constitutive differential growth 1-Dominant (cdg1-D), was isolated utilizing the technique of activation tagging. cdg1-D showed pleiotropic phenotype including dwarfism, exaggerated leaf epinasty, and twisted or spiral growth in hypocotyl, inflorescence stem, and petiole. Hypocotyls of cdg1-D were longer than those of wild type under light conditions. The phenotype was caused by activation tagging of CDG1 gene that encodes a receptor-like cytoplasmic kinase of RLCKVII subfamily. When treated with high concentrations of brassinolide, light-grown wild-type seedlings showed long hypocotyls and strong leaf epinasty as observed in cdg1-D seedlings. Treatment of cdg1-D with brassinazole, a specific inhibitor of brassinosteroid (BR) biosynthesis, did not rescue the mutant phenotype. Gene expression of CONSTITUTIVE PHOTOMORPHOGENESIS AND DWARFISM involved in BR biosynthesis and phyB ACTIVATION-TAGGED SUPPRESSOR1 that inactivates BR was repressed and induced, respectively, in cdg1-D plants, suggesting constitutive activation of BR signaling in the mutant. CDG1 was expressed at a very low level in all the organs of the wild type tested. We isolated two independent intragenic suppressors of cdg1-D. However, they showed normal morphology and responded to BR in a similar manner to wild type. Taken together, CDG1 gene may interfere with signal transduction of BR when overexpressed, but is not an essential factor for it in the wild type.