机采紧凑型棉花类固醇5α-还原酶基因(GhDET2)单核苷酸多态性

Single Nucleotide Polymorphism of Steroid 5 Alpha-reductase Gene(GhDET2) in Compact Cotton Germplasms Adapt for Picking Mechanization

油菜素类固醇参与了植物节间的发育过程,类固醇5α-还原酶基因(GhDET2)是调控该物质生物合成的一个关键基因。为了明确棉花不同株型种质GhDET2在基因组中的异同,本研究依据GenBank中该基因的mRNA序列设计引物,对11份适宜机采紧凑型和1份松散的棉花材料基因组DNA扩增及PCR产物测序,采用Geneious Pro软件对编码区序列进行分析比较。结果显示DET2基因在参试材料间一致性为98.9%,在编码区发现18个碱基易突变位点,其中涉及到编码氨基酸变化的碱基位点6个,其中松散型材料特异位点1个。依据氨基酸序列相似度的聚类结果与果节长度数据符合程度很好,可以推测GhDET2基因碱基序列变化引起的氨基酸的改变,可能影响油菜素类固醇的合成代谢,进而调节棉花果枝上果节的伸长。

GhDET2, a steroid 5α-reductase, is considered to catalyze a major rate-limiting in brassinosteroid （BR） biosynthesis, which has a great role in plant internode development. The objective of this research is to examine the differences in cotton genomes between compact germplasm and loose ones. Based on the data ofDET2 mRNA in the GeneBank, gene specific primer were designed. The coding region of GhDET2 gene was amplified by PCR from genomic DNA of eleven compact cotton germplasm adapt for picking mechanization and one cotton loose material and PCR products were directly sequenced. The analysis results of sequencing and comparison by Geneious Pro software showed consistency of DET2 gene among the tested materials was 98.9%; there were at total of 18 single nucleotides polymorphisms （SNP）, of which 6 resulted in amino acid polymorphisms, including one specific loci of loose material; according to clustering results be established on DET2 amino acid sequence, and the length of the first fruit node of the forth fruit branch of clustered materials each group was similar. We can conclude that the SNPs can cause the amino acid change of DET2, then affect synthesis or metabolism of BR, who regulate elongation of branch.