Red light induced SGT3 gene expression and functional analysis of the SGT3 promoter in potato
CUI Tong-xia;BAI Jiang-ping;WEI Gui-ming;ZHAO Xu;WANG Di;ZHANG Jin-wen;Gansu Key Laboratory of Crop Improvement & Germplasm Enhancement,Gansu Provincial Key Lab of Aridland Crop Science,Agronomy Faculty,Gansu Agricultural University;Gansu State Farms Academy of Agricultural Researches;
Rhamnosyltransferase(SGT3)is a key enzyme involved in synthesis of plant glycoalkaloids,and mainly catalyzes the transformation ofα-solanine andα-chaconine from theirβ-form.We studied the SGT3gene expression and its promoter function in potato cultivars(Solanum tuberosum),and found that after 24hours red light treatment,the transcriptional expression of SGT3was increased 26.8fold compared with control(under dark).The data thus suggested that red light induced the expression of SGT3.To further understand the regulation mechanism of SGT3,the putative SGT3promoter region(2449bp upstream of the open reading frame)was cloned and the sequence was analyzed to predict the cis-elements including promoter core sequences, enhancer sequences,inhibiting sequences,pathogen-responsive element,drought-and ABA-responsive element,and a few light-regulated elements.The transcription start site of the promoter is located 152bp upstream of the translation start site.To study the function of the SGT3promoter,the GUS expression vector driven by SGT3or CMV 35Spromoter were constructed and transformed to tobacco leaves to analyze the transient expression and stable expression.The results demonstrated that the SGT3promoter can drive the expression of GUS,but the expression level was less than that driven by the CMV 35Spromoter.The highest GUS expression was detected in tobacco leaves transformed by P572and P979but the GUS expression was decreased with P1312and P1870.More positive regulatory elements were observed within 1000bp upstream of the start code.The tissue specificity analysis indicated that the SGT3driven GUS expression was mainly concentrated in the veins of the tobacco leaves,but was not detected in mesophyll cells.In the root,GUS was detected in meristem and vascular tissues.In the stem,GUS was detected in epidermis,xylem and phloem of tobacco stems.
【Fund】： 973计划前期研究专项(2010CB134404);; 国家自然科学基金项目(31260343)资助
【CateGory Index】： S532
【CateGory Index】： S532