棉花赤霉素不敏感矮化GID1同源基因的克隆和表达分析  

Cloning and Expression Profiling of Gibberellin Insensitive Dwarf GID1 Homologous Genes from Cotton

作　　者：董静[1] 尹梦回[1] 杨帆[1] 赵娟[1] 覃珊[1] 侯磊[1] 罗明[1] 裴炎[1] 肖月华[1] 

机构地区：[1]西南大学生物技术中心/农业部生物技术和作物品质改良重点实验室,重庆400716

出　　处：《作物学报》2009年第10期1822-1830,共9页Acta Agronomica Sinica

基　　金：国家高技术研究发展计划(863计划)项目(2007AA10Z134)资助

摘　　要：作为赤霉素（GA）受体,GID1是其重要的信号传导组分。为研究GA在棉花发育（特别是纤维发育）中的作用,本文在EST序列的基础上克隆了6个棉花GID1同源基因（GhGID1-1-6）。多重序列分析表明,棉花GID1同源蛋白GhGID1-1-6与拟南芥和水稻的GID1蛋白高度同源,具有多个与GA和DELLA蛋白的结合位点以及激素敏感酯酶家族保守域HGG和GXSXG。定量RT-PCR分析表明,GhGID1-1-6基因在棉花不同器官和组织中表达水平有差异,其中GhGID1-1和GhGID1-2在花器官中高表达,GhGID1-4基因在纤维和根中优势表达。胚珠体外培养基中外加GA使GID1同源基因表达水平发生变化,GhGID1-1和GhGID1-2基因的表达水平明显受GA抑制。比较发现,在胚珠和纤维中优势表达的GID1同源基因不同,GID1基因表达水平随发育时期变化的趋势也不相同,表明棉花胚珠和纤维具有相对独立的GA信号识别系统。Gibberellins （GA） play an important role in regulating cotton fiber development. As the GA receptor, GID 1 is an essential component of GA signaling pathway. To advance our understanding of GA＇s functions in cotton development （especially fiber development）, we cloned six cotton GID1 homologous genes （GhGID1-1-6, accession No. are FJ790125-FJ790130） by searching EST sequences, extending the flanking sequences by Y-shaped adaptor dependent extension （YADE） method and amplifying the full-length cDNA by 3＇-RACE. Multiple sequence alignment indicated that the deduced GhGID1-1-6 proteins shared high sequence identity with GIDls from other species and contained multiple binding sites with GA and DELLA protein as well as HGG and GXSXG domains conserved in hormone-sensitive lipase （HSL） family. Three amino acid residuals （G^169, G^196, and R^251） with the rice GID1 function were also conserved in cotton GIDls. In the phylogenetic tree of GhGID1-1-6 and other GID1 proteins with known function, GhGID1-1-6 were clustered with 3 Arabidopsis GID1 proteins, and distantly related to GIDls from rice and S. moellendorffii. Quantitative RT-PCR was employed to detect the expression levels of GhGID1-1-6 in various organs and tissues. The transcripts of GhGID1-1-6 could be detected in all the organs and tissues investigated （including roots, hypocotyls, leaves, petals, anthers, ovules and fibers）, although with various levels. GhGIDI-1 and GhGID1-2 expressed mainly in floral organs, while GhG1D1-4 expressed preferentially in fiber and root. Exogenous GA added in medium led to alteration of gene expression level in the in vitro cultivated ovules, and the expressions of GhG1D1-1 and GhGID1-2 were obviously inhibited by GA. These results suggested that GhGID1-1-6 might encode biologically functional GID1 homologues involved in GA signaling in cotton. To further clarify GID1 genes related to fiber development, we compared GhGIDIs＇ expression in developing ovule （from 6 to 18 days post anthesis, DPA）

关 键 词：GID1 棉花 纤维发育 表达特异性 

分 类 号：S562[农业科学—作物学]