小麦类成束阿拉伯半乳糖蛋白编码基因TaFLA的克隆与表达分析

为研究类成束阿拉伯半乳糖蛋白编码基因Fasciclin-Like Arabinogalactan-protein(FLA)在小麦抗逆境胁迫和花药发育中的作用,利用同源克隆法从小麦中获得1个FLA基因,命名为TaFLA,并对其组织表达特性和逆境胁迫表达特性分别进行了分析。序列分析结果表明,TaFLA基因含有1个1 530 bp的完整开放阅读框,编码509个氨基酸;TaFLA蛋白含有预测的N-末端信号肽,两个Fasciclin结构域(氨基酸205-300、371-474)和两个N-糖基化位点(氨基酸369和487)。系统演化分析结果表明,TaFLA基因与二粒小麦处于同一分支,其亲缘关系最近。荧光定量表达分析结果表明,TaFLA基因在小麦根、小穗(除去雄蕊)、减数分裂前和分裂时期的雄蕊中均有表达,其中,小穗(除去雄蕊)中表达量最高;在低温胁迫处理下,TaFLA基因表达上调,而在干旱、高盐和ABA处理下,表达量均有所下降;温敏雄性不育系BS366在不育环境(低温)下,TaFLA基因在雄蕊发育关键时期(二分体时期)大量表达,约为可育环境(高温)下表达量的29倍。

Cloning and Expression Analysis of TaFLA Encoding a Fasciclin-like Arabinogalactan Protein in Wheat

In order to study the role of Fasciclin-like Arabinogalactan-protein(FLA) in wheat stress resistance and anther development,an FLA gene was obtained from wheat by homologous cloning,named as TaFLA. The tissue expression characteristics and expression characteristics under stresses were analyzed. Sequence analysis revealed that the TaFLA gene contains a complete open reading frame of 1 530 bp encoding 509 amino acids; the TaFLA protein contains a putative N-terminal signal peptide,two fasciclin domains(amino acid sites 205-300,371-474) and two N-glycosylation sites (amino acid sites 369 and 487). The results of systematic evolution analysis indicated that the TaFLA gene was clustered as the two-grain wheat,with the closest genetic relationship. Fluorescence quantitative expression analysis showed that TaFLA gene was expressed in wheat roots,spikelets(removed stamens),stamens before meiosis,and stamens in meiosis,among which spikelets(removed stamens) showed the highest expression. The expression of TaFLA gene was up-regulated under low temperature stress treatment,however,the expression level decreased under drought,high salt and ABA treatments. The high expression of TaFLA was detected in stamens of BS366(a thermo-sensitive male sterile wheat line)at dyad stage in critical temperature(low temperature),which was about 29-fold higher than that in the fertile environment(high temperature).