甜高粱蔗糖磷酸合成酶基因(SPS3-1)的克隆与序列分析

Isolation and Characterization of Sucrose Phosphate Synthase Gene (SPS3-1) in Sweet Sorghum (Sorghum bicolor (L.) Moench)

以甘蔗蔗糖磷酸合成酶基因(SPSⅢ-2,NCBI登录号为EU278617)cDNA序列为探针,对高粱EST数据库进行同源检索、筛选和拼接,后经基因组PCR、分子克隆、序列分析验证分离了甜高粱蔗糖磷酸合成酶基因组DNA序列(SPS3-1,GeneBank登录号为FJ750250)。该序列全长6325bp,包含13个外显子和12个内含子,其cDNA序列包含一个2895bp的开放读码框,编码964个氨基酸,此蛋白属于SPSDⅢ家族。将此序列与高粱基因组DNA序列进行比较,发现SPS3-1基因位于高粱第4染色体上。将推测的甜高粱SPS3-1蛋白序列与甘蔗、水稻、玉米等物种进行同源进化分析,均表现出极高的保守性。

Sucrose phosphate synthase （SPS） plays an important role in plant growth and development. It can regulate sucrose accumulation in storage tissue of many plants. In this paper, a novel full-length sweet sorghum Sucrose phosphate synthase gene （SPS3-1, GeneBank accession EU278617） DNA sequence was cloned by blasting the sorghum EST database using sugarcane SPSⅢ-2 （GenBank accession, EU278617） cDNA sequence as a querying probe. The full-length DNA of 6 325 bp contains 13 exons and 12 introns, and cDNA sequence contains a complete ORF encoding 964 amino acids, which was very conservative among sugarcane, rice, wheat and so on. It was discovered that SPS3-1 was located in the fourth chromosome by comparing with the whole sorghum genomic DNA sequences. The results will provide a basis for further research on molecular mechanism of sucrose accumulation in sweet sorghum.