辣椒雄性不育系葡萄糖-6-磷酸脱氢酶基因的克隆及表达分析

为了深入研究辣椒雄性不育与能量代谢之间的关系,该研究以辣椒近缘物种番茄的葡萄糖-6-磷酸脱氢酶基因(G6PDH)同源序列为基础,采用电子克隆的方法克隆出辣椒CaG6PDH基因。利用荧光定量PCR技术,对辣椒雄性不育系9704A与其保持系9704B花蕾发育的不同阶段,以及保持系9704B不同组织(茎、叶、花、果皮、胎座、种子)中CaG6PDH基因进行表达分析。结果表明:两系中获得的CaG6PDH基因的编码序列一致,全长1 533bp,编码510个氨基酸残基;辣椒CaG6PDH基因在保持系不同组织中表达量存在差异,胎座中表达量最高,茎中表达量最低;辣椒CaG6PDH基因的表达量在花蕾发育的不同阶段雄性不育系均高于保持系,此种差异在小孢子发育的单核期与成熟期尤为明显,这种差异可能使雄性不育系能量代谢供应出现异常,从而影响小孢子的正常发育而导致雄性败育。

Clone and Expression Analyses of CaG6PDH Gene from Pepper Cytoplasmic Male Sterility Line

In order to study the relationship between of pepper cytoplasmic male sterility and energy metabolism,we cloned pepper glucose-6-phosphate dehydrogenase gene (CaG6PDH) based on the G6PDH homologous sequences of the related species tomato by the electronic cloning in this research.Real-time quantitative-PCR was used to analyze the gene expression levels in the different stages of flower development in the cytoplasmic male sterility line (9704A) and its maintainer line (9704B),and different tissues(stem,leaf,flower,pericarp,placenta and seed) in the 9704B.The results showed that there was no difference of cDNA sequences between the CaG6PDH in the 9704A and the 9704B.Sequence prediction showed that the 1 533 bp cDNA sequences represent 1 single gene,which encodes 510 amino acids.CaG6PDH gene has a different expression in the different tissues in the 9704B,the highest in the placenta and the lowest in the stem.CaG6PDH gene expression in 9704A was higher than that in 9704B during the different stages of flower development,especially in the uninucleate microspore stage and mature pollen stage.The abnormal expression level of CaG6PDH in the 9704A disturbed the balance of energy metabolism and interfered the development of microspore,then resulted male sterility in the pepper.