小麦淀粉合成相关酶基因SSⅡa、SBEⅡa和SBEⅡb表达序列多态性及对淀粉质量分数的影响

Correlation Analysis between Expression Sequence Polymorphisms of the Genes Encoding Wheat Starch Synthesis Enzymes SSⅡa,SBEⅡaand SBEⅡb,and Starch Mass Fraction

为了探究小麦淀粉合成相关酶SSⅡa、SBEⅡa和SBEⅡb基因表达序列核苷酸多态性及其与淀粉质量分数的关系,根据GenBank中已公布的基因序列设计特异引物,克隆基因的表达序列并测序,通过Clustal X2比对分析,用Dnasp 5.0计算核苷酸多态性信息,并建树做单倍型与淀粉质量分数的相关分析。结果表明,克隆得到3个基因的ORF(Open reading frame)序列,NCBI/Blast同源比对SSⅡa、SBEⅡa和SBEⅡb与GenBank中已登记的序列的同源性分别为98.19%、98.64%和99.04%。在SSⅡa、SBEⅡa和SBEⅡb中分别发现40、14和18个SNP位点,其中共包括4个InDel。在SSⅡa中,其第2外显子区为变异富集区,Tajima’s D检验D值均不显著。可见,这3个基因的多态性信息均较丰富,其单核苷酸多态性与小麦淀粉质量分数之间存在一定的对应关系。

To explore the correlation between nucleotide sequence polymorphism of the genes encoding wheat starch synthesis related enzymes SSⅡ a,SBEⅡa and SBEⅡb,and starch mass fractions, ORF （open reading frame） sequences of SSⅡa , SBEⅡa and SBEⅡb genes were cloned from twelve wheat varieties with different starch mass fractions,and Clustal X2 software was further used to analyze cDNA sequences of these genes. Homology analysis on the nucleotide sequences of these genes showed that the cDNA sequences of SSⅡa , SBEⅡa and SBEⅡb genes shared 98.19%,98.64% and 99.04% identities to their published sequences,respectively. In this study,there were 40 （ SSⅡa ） ,14 （ SBEⅡa ） and 18 （ SBEⅡb ） SNPs loci of SSⅡa , SBEⅡa and SBEⅡb genes,respectively. Using Dnasp 5.0 bioinformatics software,Tajima＇s D of these three genes could be insignificant. Especially, there was a rich region of variation in the second exon of SSⅡa . These data showed that polymorphism information of the SSⅡa , SBEⅡa and SBEⅡb genes was rich and there was a certain correspondence between nucleotide polymorphisms and starch mass fractions.