华山新麦草蔗糖:蔗糖1-果糖基转移酶基因Ph-1-SST的克隆及序列分析

蔗糖:蔗糖1-果糖基转移酶基因1-SST在植物逆境胁迫反应中起重要作用。为了挖掘华山新麦草(Psathyrostachys huashanica Keng)抗非生物胁迫关键功能基因,以华山新麦草叶片为材料,利用RT-PCR结合RACE技术克隆1-SST基因的全长cDNA,命名为Ph-1-SST,登录号为KX761897。通过PCR法扩增其gDNA序列,测序结果表明该基因的gDNA和cDNA序列长度分别为3 344bp和2 001bp,编码666个氨基酸残基,序列结构分析结果表明该基因含4个外显子3个内含子,预测该蛋白相对分子质量为72.9ku,理论等电点为4.87。序列比对显示,该基因与大麦1-SST基因编码蛋白的相似性最高(90%),为糖基水解酶32家族成员。对1-SST氨基酸序列的系统进化树分析显示,Ph-1-SST及其同源蛋白位于不同分支,初步推断此全长cDNA是华山新麦草中编码蔗糖:蔗糖1-果糖基转移酶的一个新基因。结果为作物非生物胁迫改良提供重要基因资源。

Cloning and Sequence Analysis of Sucrose:Sucrose-1-fructosyltransferase ( 1-SST) Gene from Psathyrostachys huashanica

The sucrose:sucrose-1-fructosyltransferase ( 1-SST) gene plays an important role in plant responses to abiotic stresses.To identify the key functional genes for responding abiotic stresses in Psathyrostachys huashanica Keng,the full-length cDNA of 1-SST was cloned by using rapid-amplification of cDNA ends and RT-PCR techniques,and designated as Ph-1-SST (GenBank accession No.KX761897).The genomic DNA (gDNA) was cloned by using PCR,and sequence analysis showed that the full length gDNA of Ph-1-SST was 3 344 bp with four exons and three introns,and that the cDNA of Ph-1-SST contained a 2001 bp ORF encoding a protein of 666 amino acids with a predicted molecular weight of 72.9 ku and theoretical isoelectric point of 4.87.Sequence alignment demonstrated that Ph-1-SST shared high similarity of up to 90% with 1-SST from barley,which belonged to the glycosyl hydrolase 32 family.Phylogenetic analysis indicated that Ph-1-SST formed a single branch in the 1-SSTs group,and thus Ph-1-SST was a possible new 1-SST gene from Psathyrostachys huashanica.Thus,we obtained a gene resource to facilitate the genetic improvement of abiotic stress resistance in crops.