杉木蔗糖转运蛋白SUT基因的克隆和功能分析

蔗糖转运蛋白又称蔗糖-质子共转运蛋白，简称SUT(sucrose transporter)或者SUC(sucrose carriers)，主要担负植物光合产物——蔗糖的跨膜运输与分配调控，在植物体内完成使蔗糖从“源”到“库”的运输。采用CTAB法提取杉木总RNA，通过RT-PCR得到cDNA，设计基因特异性引物，从1年生无性系杉木幼苗嫩叶中克隆SUT基因，并利用生物信息学方法分析SUT的基本结构、进化关系、理化性质。结果表明，在电泳图上总RNA的结构完整，28 S的亮度约为18 S的2倍；A260/A280为2.20，A260/A230为2.31；杉木SUT基因编码区全长为1 782 bp，共编码593个氨基酸，是具有SUT基因家族的典型12个跨膜区；通过系统进化树的分析发现，杉木SUT与无油樟SUT的亲缘性较高，SUT蛋白属于疏水性蛋白。

Cloning and Functional Analysis of Chinese Fir Sucrose Transporter SUT Gene

The sucrose transporter,also known as the sucrose-proton cotransporter,abbreviated as SUT(sucrose transporter)or SUC(sucrose carriers)is mainly responsible for the transmembrane transport and distribution regulation of plant photosynthetic product-sucrose.It helps the transportation of sucrose from“source”to“library”in plants.In this study,the total RNA of Chinese fir was extracted by CTAB method.The cDNA was obtained by RT-PCR,and the gene-specific primers were designed.The SUT gene was cloned from the young leaves of annual clones of Chinese fir.The basic structure,evolution,and physico-chemical properties of SUT were analyzed by bioinformatics.The electropherogram indicated that the structure of total RNA was complete,the brightness of 28 S was about twice that of 18 S;A260/A280 was 2.20,A260/A230 was 2.31;and the length of Chinese SUT gene coding region was 1782 bp.It encoded 593 amino acids and was a typical 12 transmembrane region with SUT gene family.Through phylogenetic tree analysis,it was found that Chinese fir SUT had higher affinity with oil-free SUT,and SUT protein was hydrophobic.