马铃薯StSUT2基因在烟草中过表达提高其耐盐性

Overexpression of Potato Sucrose Transporter2(StSUT2)Gene Enhances Tolerrance of Tobacco to Salinity

【目的】为明确马铃薯蔗糖转运蛋白(SUT2)对盐胁迫的响应,本研究对StSUT2的功能进行初探。【方法】通过同源克隆技术得到马铃薯StSUT2基因并进行生物信息学分析,使用荧光定量PCR技术检测马铃薯青薯9号不同器官中SUT2基因在盐胁迫下表达量的变化,随即构建表达载体并遗传转化烟草,测定转基因烟草在盐胁迫下脯氨酸、可溶性蛋白和可溶性糖含量的变化。【结果】①马铃薯StSUT2基因CDS长度为1818 bp,编码605个氨基酸;系统进化树分析表明,马铃薯StSUT2与番茄亲缘关系最近。②马铃薯StSUT2基因可被盐胁迫诱导,其中根、茎中的表达量在胁迫8 h最大,而叶中的表达量在4 h最大。③构建表达载体pJAM1502-StSUT2并转化烟草,经PCR和qRT-PCR鉴定,获得6株转基因植株,并选取表达量最高者进行后续实验。④盐胁迫下测定野生型与过表达植株中脯氨酸、可溶性蛋白以及可溶性糖含量发现,过表达植株中脯氨酸、可溶性蛋白以及可溶性糖含量均高于野生型。【结论】StSUT2可能会通过提高渗透性物质含量来增强植物的耐盐性。

【Objective】In order to clarify the salt tolerance of sucrose transport protein(SUT2)in potato(Solanum tuberosum),this study explored the function of StSTU2.【Method】A gene StSUT2 was cloned using the method of homologous cloning and analyzed by bioinformatics.The qRT-PCR technology was used to detect the change of StSUT2 expression under Salt dress.Then the expression was constructed and genetically transformed into tobacco.Changes of proline,soluble protein and soluble sugar content of transgenic tobacco under salt stress were determined.【Result】(i)The CDS sequence of StSUT2 was 1818 bp,encoded a polypeptide of 605 amino acids;Phylogenetic analysis showed that StSUT2 protein had the closest genetic relationship to Solanum lycopersicum.(ii)The expression of StSUT2 could be induced by salt dress,and the highest expression was at 8 hours in root and stem,but at 4 hours in leaf.(iii)The expression vector pJAM1502-StSUT2 was constructed and transformed into tobacco.6 transgenic plants were identified by PCR,and the highest expression level was selected for following experiment by qRT-PCR.(iv)We analyzed the physiological indicators,including proline,soluble protein and soluble sugar contents that were elevated in transgenic plants than that of the control.【Conlusion】StSUT2 may increase salt tolerance in plants by increasing osmotic content.