玉米耐旱相关基因dbf1的序列变异分析

Nucleotide Diversity of Drought Tolerance Related Maize Gene dbf1

玉米dbf1基因在干旱胁迫下的编码产物与DIP1蛋白相结合,调控植物激素脱落酸(ABA)响应基因rab17的表达,从而提高耐旱性。以B73的dbf1基因组序列为模板,对104个玉米自交系的dbf1基因进行测序,研究玉米dbf1基因的序列多态性。多态性分析表明,在全长为2 118 bp的序列中共发现48个SNP和12个In Del。尽管大部分变异位点集中在非编码区,但编码区的1个In Del和3个非同义突变位点的变异可以产生氨基酸序列改变。玉米dbf1基因的全长序列和编码区序列的变异位点可以分别将该基因划分成33和11种单倍型,并且编码7种蛋白质。在供试材料中,dbf1基因至少经历了9次重组,中性检测表明,该基因的进化没有偏离中性选择。

The protein product encoded by maize dbf1 gene will combine with DIP1 protein to regulate ABA re sponsive gene rab17 expression under drought stress, resulting in improvement of drought tolerance. In order to illustrate the sequence polymorphism of maize gene dbf1, the dbf1 gene in 104 maize inbred lines was sequenced, using the genomic sequence of B73 as the reference. A total of 48 SNPs and 12 InDels were identified among 2 118 bp nu- cleotide sequences at this locus. Although most of these polymorphic sites were found to be located in non-coding regions, one InDel and three nonsynonymous mutations in coding regions may change the amino acid sequences. The polymorphic sites in the genomic sequences andcoding sequences of maize dbf1 classified all the tested inbred lines into 33 and 11 haplotypes, respectively. In addition, seven deferring DBF1 proteins were encoded by these inbred lines. Analysis of the polymorphism sites revealed that at least 9 recombination events had occurred in dbf1 locus. Furthermore, the evolution of maize dbf1 gene in the tested lines fit the neutral theory model.