毛竹PeSCL3基因表达特征及其启动子活性研究

为探讨毛竹(Phyllostachys edulis)SCL3基因的表达特征及其启动子活性,采用同源克隆的方法从毛竹中分离到SCL3同源基因Pe SCL3的编码区(ORF)和上游启动子序列(Pe SCL3p)。序列分析表明,Pe SCL3的ORF为1335 bp,推测编码含444氨基酸的蛋白,该蛋白与水稻(Oryza sativa)的SCL3同源性高达93.9%。Pe SCL3p长度为1358 bp,含有脱落酸(ABA)应答元件ABRE、赤霉素(GA3)应答元件GARE-motif和P-box、干旱诱导MYB结合位点等多种作用元件。实时定量PCR分析结果表明,Pe SCL3在毛竹叶中的表达丰度最高,其次是茎和根,而鞘中的最低;Pe SCL3的表达受GA3的抑制,受ABA、Na Cl和干旱的诱导。转Pe SCL3p∷GUS拟南芥(Arabidposis thaliana)的GUS染色结果表明,根尖、顶端生长点和子叶叶柄均被染成蓝色,尤其根尖的染色最深。这表明Pe SCL3对毛竹的生长发育,尤其是根系,可能起着重要的调控作用。

Expression Characteristics and Promoter Activity Analysis of PeSCL3 Gene from Phyllostachys edulis

In order to reveal the expression characteristics and promoter activity of SCL3 in Phyllostachys edulis, the open reading frame (ORF) of PeSCL3 and its upstream promoter sequence (PeSCL3p) were cloned from P. edulis by using homologous cloning method. Sequence analysis showed that the length of PeSCL3 ORF was 1335 bp, encoding a protein with 444 amino acids, which shared 93.9% homology with SCL3 from Oryza sativa. The length of PeSCL3p was 1358 bp, containing many kinds of cis-acting regulatory elements, such as abscisic acid response (ABRE), gibberellin-responsive element (GARE-motif and P-box), and drought-induced MYB binding sites, etc. Based on real-time quantitative PCR, the expression of PeSCL3 in leaf was the highest, following by stem and root, and the least in sheath. Besides, the expression of PeSCL3 was inhibited by GA₃, while it was induced by ABA, NaCl and drought. The GUS staining result of transgenic Arabidopsis thaliana with PeSCL3p::GUS showed that root tip, apical meristem and cotyledon petiole were all stained blue, especially in root tip with the deepest staining. So, these indicated that PeSCL3 might play an important role in regulating the growth and development of P. edulis, especially for that of root.