珍珠黄杨矮化基因BsGAI2的克隆及功能分析

GA信号转导途径或生物合成受阻是导致植物矮化的重要因素,而DELLA蛋白是GA信号传导通路中一类重要的负调节因子。本研究利用同源克隆和RACE技术,从珍珠黄杨中克隆得到BsGAI2基因的c DNA序列,全长为2305 bp,包括1836 bp完整的ORF。实时荧光定量表达分析表明,BsGAI2基因在珍珠黄杨茎中表达量最高,在根中表达量最低;BsGAI2转基因烟草呈明显矮化,节间变短,长势较慢,延迟开花等特征。利用GFP荧光检测方法鉴定转化型烟草,发现转化苗的叶、茎中均有荧光信号,并且茎木质部有明亮富集的荧光信号。这些结果均表明BsGAI2基因可能在珍珠黄杨茎节间缩短导致矮化的过程中扮演重要角色。本研究分析了BsGAI2基因编码蛋白的理化性质和功能鉴定,为今后进一步研究BsGAI2基因及DELLA蛋白家族的功能提供了理论依据。

Cloning and Function Analysis on BsGAI2 Gene from Buxus sinica var. parvifolia

GA signaling transduction pathway or biosynthesis, which is impeded, is an important factor in plant dwarfing. DELLA protein is an important negative regulator in GA signaling transduction pathway. DELLA protein gene, named BsGAI2, was cloned from Buxus sinica var. parvifolia using PCR and RACE techniques. BsGAI2 contains the complete coding region, having 2576bp in full length, contains an opening frame of 1884bp. Real-time quantitative PCR demonstrated that, the amount of BsGAI2 expression was the highest in stem and the lowest in flower from Buxus sinica var. parvifolia. The transgenic tobaccos contains BsGAI2 gene, appearing dwarf, internodes shorter, growing slowly, delay flowering. The transgenic tobaccos were detected by GFP fluorescent methods, whose leaf, stem were founded fluorescent signal, and the stem xylem had bright-enriched signal. These results all indicated that BsGAI2 gene may play an important role in the process of shorting stem internode for Buxus sinica var. parvifolia dwarf. This study analyzed physical & chemical properties and functional identification of BsGAI2 gene encoding protein, which provided the theoretical basis for the further study of BsGAI2 gene and DELLA protein family.