大白菜核雄性不育相关基因BrLTP1的克隆及特征分析

Cloning and Characterization of a Genic Male Sterility-related Gene BrLTP1 in Chinese Cabbage

利用cDNA-AFLP技术分析大白菜核雄性不育两用系‘AB02’可育株(msms)和不育株(Msms)花蕾的基因表达谱,在可育株混合花蕾cDNA中扩增出1条特异条带TDF-25,通过RACE和RT-PCR技术克隆了该基因的全长cDNA序列。序列分析表明,该基因编码脂质转移蛋白,命名为BrLTP1。BrLTP1全长cDNA序列为750bp,推测编码1个包含183个氨基酸残基的前体蛋白。BrLTP1蛋白含有典型的脂质转移蛋白N端信号肽,保守的AAI结构域和半胱氨酸位点。预测BrLTP1蛋白含有多种修饰性位点,包括1个PKC磷酸化位点,2个N-糖基化位点和10个N-端豆蔻酰基化位点。基因表达模式表明,BrLTP1在两用系不育株花蕾中受到强烈抑制,在可育株的大花蕾、成熟花药以及花瓣中高水平表达。

The gene differential expression analysis was performed by cDNA-AFLP in the genic male sterile line ＇AB02＇ of Chinese cabbage,and a differentially expressed cDNA fragment,TDF-25,was only found in fertile plants.The full-length cDNA of BrLTP1,coding lipid transfer protein in Chinese cabbage,was amplified by RACE and RT-PCR.The BrLTP1 gene was 750 bp long in cDNA and hypothetical protein BrLTP1 included 183 amino acids with a signal peptide of 22 amino acids.Sequence analysis revealed that the BrLTP1 protein has ten N-myristoylation sites,two N-myristoylation sites,and one PKC phosphorylation site.Gene expression characteristics indicated that BrLTP1 was highly expressed in big flower buds and mature anthers of fertile plants,with a extremely low expression level in sterile buds.