Genetic characterization and functional analysis of the GID1 gibberellin receptors in Arabidopsis
Genetic characterization and functional analysis of the GID1 gibberellin receptors in Arabidopsis
复制标题
DOI：
10.1105/tpc.106.047415
复制
发表时间：
2006-12-01
期刊：
影响因子：
11.6
通讯作者：
Thomas, Stephen G.
中科院分区：
文献类型：
--
作者：
Griffiths, Jayne;Murase, Kohji;Thomas, Stephen G.
我们研究了三个拟南芥同系物的赤霉素（GA）受体GIBBERELLIN-INSENSITIVE DWARF 1（GID 1）的生理功能，通过确定发育的后果，GID 1失活插入突变体。虽然单个突变体正常发展，gid 1a gid 1c和gid 1a gid 1b显示降低茎高和较低的男性生育力，分别表示一些功能特异性。三重突变体表现出更严重的矮化表型比极端GA缺陷突变体ga 1 -3。花的形成发生在长的日子，但延迟，在花器官发育严重缺陷。三重突变体没有响应所施加的GA。所有三个GID 1同源物在整个发育过程中在大多数组织中表达，但表达水平不同。GA处理降低了所有三个GID 1基因的转录丰度，表明反馈调节。DELLA蛋白质修复体的ga 1 -3（RGA）积累在三重突变体，其表型可以部分挽救的RGA功能的丧失。酵母双杂交和体外pull-down实验证实GA增强了GID 1和DELLA蛋白之间的相互作用。此外，含有DELLA结构域的N-末端序列对于GID 1结合是必需的。此外，酵母三杂交测定表明，GA-GID 1复合物促进RGA和F-box蛋白SLY 1之间的相互作用，F-box蛋白SLY 1是SCFSLY 1 E3泛素连接酶的一种组分，其靶向DELLA蛋白进行降解。
We investigated the physiological function of three Arabidopsis thaliana homologs of the gibberellin (GA) receptor GIBBERELLIN-INSENSITIVE DWARF1 (GID1) by determining the developmental consequences of GID1 inactivation in insertion mutants. Although single mutants developed normally, gid1a gid1c and gid1a gid1b displayed reduced stem height and lower male fertility, respectively, indicating some functional specificity. The triple mutant displayed a dwarf phenotype more severe than that of the extreme GA-deficient mutant ga1-3. Flower formation occurred in long days but was delayed, with severe defects in floral organ development. The triple mutant did not respond to applied GA. All three GID1 homologs were expressed in most tissues throughout development but differed in expression level. GA treatment reduced transcript abundance for all three GID1 genes, suggesting feedback regulation. The DELLA protein REPRESSOR OF ga1-3 (RGA) accumulated in the triple mutant, whose phenotype could be partially rescued by loss of RGA function. Yeast two-hybrid and in vitro pull-down assays confirmed that GA enhances the interaction between GID1 and DELLA proteins. In addition, the N-terminal sequence containing the DELLA domain is necessary for GID1 binding. Furthermore, yeast three-hybrid assays showed that the GA-GID1 complex promotes the interaction between RGA and the F-box protein SLY1, a component of the SCFSLY1 E3 ubiquitin ligase that targets the DELLA protein for degradation.