二角山羊草Pinb基因的克隆与表达分析

Cloning and Expression of Pinb Gene in Aegilops bicornis

根据已报道的小麦Pinb基因的保守序列,设计合成了1对特异性引物,对二角山羊草(Aegilops bicornis,SS)的基因组DNA进行Pinb基因扩增、克隆、序列分析,发现了1个新型Pinb等位基因,基因长360bp,编码119个氨基酸残基,对应于麦类作物PinB成熟蛋白结构区域,具有其特有的WPTKWWK色氨酸结构域和10个半胱氨酸所形成的5个二硫键结构。与软粒小麦cv.Capitole的Pinb-D1a相比较,其核苷酸和氨基酸同源性分别为93.1%和91.6%。RT-PCR证实了Pinb基因在籽粒胚乳中的表达。研究结果表明,二角山羊草中包含着与小麦差异较大的籽粒硬度控制基因,为栽培小麦品质改良提供了丰富的遗传资源。

According to the reported conservative sequences of Pinb gene,a pair of specific primers were designed to amplify,clone and sequence Pinb gene of DNA genome in Aegilops bicornis （SS） and a new allele of Pinb was found. The allele was 360 bp long,encoded 119 amino acid residuals,corresponded with the mature protein structure region of PinB in cereal crops, had its specific tryptophan motif of WPTKWWK and contained five disulphide bonds formed by ten cysteines. In nucleitide and amino acid sequences,it is 93.1% and 91.6% as homologous as Pinb-Dla of T. aestivum cv. Capitole,respectively. It was proved by RT-PCR that Pinb gene expressed itself in grain endosperm. The results indicated that Aegilops bicornis contained the gene regulating grain hardness that greatly differed from that in wheat so that it could provide rich genetic resources for wheat quality improvement.