Expression Analysis Of Potato StSUT Gene And Construction Of StSUT2 Gene Expression Vector

Potato(Solanum tuberosum L.)is the world's fourth largest food crop after wheat,rice and corn,and is cultivated in more than 160 countries around the world.The plant sucrose transporter(SUT)is mainly responsible for the long-distance transportation of sucrose from the "source" organ to the "library" organ,affecting the growth and development of the plant,and determining the yield and quality of the crop.Three SUT genes were isolated from potato,StSUT1,StSUT2 and StSUT4.Recent studies have shown that StSUT1 and StSUT4 affect potato plant growth,tuber yield and photoperiod-regulated gene expression,while the physiological function of StSUT2 remains unclear.There is still a lack of in-depth research on its expression patterns and subcellular localization.This study analyzed the expression patterns of three StSUTs in different tissues and organs of potato,and constructed SUT2 plant overexpression vector and prokaryotic expression vector,which mainly obtained the following experimental results:(1)Using qPCR technology,the relative expression levels of SUT genes of potato "Favorita" and "Shepody" in different light time and different tissues and organs were analyzed.The results showed that:The expression patterns of the two potato cultivars were similar,and the StSUT1 gene was mainly expressed in mature leaves and old leaves,and was affected by the illumination time.The StSUT4 gene is mainly expressed in flowers and old leaves,and is also highly expressed in stems,roots and stolons,and is also affected by light time.The StSUT2 gene is mainly expressed in flowers and old leaves,and is also highly expressed in mature leaves,stems,roots and stolons,but is not affected by light time.The relative expression of StSUT gene in each tissue organ was almost higher than 16 h at 4 h,but there were some exceptions.These phenomena may be related to tuber formation in potato.(2)Total RNA was extracted from the leaves of potato "Atlantic" varieties,and the cDNA obtained by reverse transcription was used as a template.The StSUT2 gene was amplified by PCR and the entry vector pENTR-StSUT2 was constructed by TOPO directed cloning.By PCR and sequence analysis,the fragment was 1818 bp in size and encoded 605 amino acid residues.It was 98% homologous to the base sequence reported in the literature by sequence analysis.It was constructed by LR recombination reaction in Gateway technology.The pGWB2-StSUT2 plant overexpression vector was transferred into Agrobacterium GV3101.(3)Using the cDNA of potato "Atlantic" as a template,the StSUT2 gene was cloned and ligated with pET-21 d vector to transform BL21(DE3)E.coli,and the prokaryotic expressionvector of pET-StSUT2 was obtained.The above study laid the foundation for the subsequent exploration of the function of potato StSUT2.