小麦抗旱相关基因TaCRT-D单核苷酸多态性分析

Single Nucleotide Polymorphism of TaCRT-D Gene Associated with Drought Resistance in Wheat Germplasm

【目的】钙网蛋白(CRT)是细胞内质网膜上的钙结合蛋白,参与多种细胞功能的调节。研究小麦钙网蛋白基因TaCRT-D单核苷酸多态性,并分析其与抗旱性的关系。【方法】以苗期抗旱性不同的37份六倍体普通小麦和3份普通小麦D基因组供体种粗山羊草为材料,通过直接测序分析TaCRT-D基因的单核苷酸多态性(SNP)及其与抗旱性的关系。【结果】TaCRT-D基因DNA长度为4 001 bp,在长达160 040 bp的核苷酸序列中共检测到105个单核苷酸变异位点,包括84个SNP和21个InDel,二者出现的频率分别为1/1 905和1/7 621,编码区的核苷酸多样性值(π)小于非编码区,说明编码区所承受的选择压力较大,遗传变异小于非编码区。单倍型分析表明,40份供试材料分为8种单倍型,其中单倍型H1中11份材料包括4份中等抗旱材料和7份干旱敏感材料;单倍型H3、H4和H7既有抗旱性强的材料也有干旱敏感材料;单倍型H5只包括3份小麦D基因组供体种材料。【结论】普通小麦TaCRT-D基因中SNP频率较低,TaCRT-D基因单核苷酸多态性与小麦苗期抗旱性之间没有明显的对应关系。

【Objective】Calreticulin（CRT） is one of the major Ca2＋ binding proteins in cell endoplasmic reticulum（ER）,which is concerned with many cellular processes.The objective of the present study was to detect single nucleotide polymorphisms（SNP） of TaCRT-D and determine the relationship between SNP and drought resistance.【Method】Thirty-seven hexaploid wheat accessions with different drought resistance at seedling stage and their D genome donor species,three Aegilpos tauschii were used as the plant materials.The nucleotide polymorphism in TaCRT-D gene was detected by sequencing.【Result】The full-length sequence of TaCRT-D genomic DNA was 4 001 bp.One hundred and five nucleotide mutations were identified,including 84 SNP and 21 InDel in a total of 160 040 bp nucleotide acid sequence.The frequencies of SNP and InDel were 1/1 905 and 1/7 621,respectively.The nucleotide diversity value（π） in coding region of TaCRT-D was lower than that in non-coding region,which suggested that genetic variation in coding region was smaller than that in non-coding region and the former suffered stronger selection pressure than later.Eight haplotypes were identified from 40 plant materials.Among them,haplotype H5 contained only three Aegilops tauschii who were the donor species of common wheat D genome,bigger haplotype H1,H3,H4 and H7 comprised drought-resistant accessions and drought-sensitive accessions,synchronously.【Conclusion】The results of research showed that the frequency of SNP in TaCRT-D was very low,and there was no clear correlation between SNPs in TaCRT-D and drought resistance at wheat seedling stage.