Isolation And Functional Characterization Analysis Of SlSWEET14 Promoter Specifically Expressed In Tomato Fruit

SWEETs gene family is a newly discovered membrane transport protein,which is involved in the transport of sucrose,fructose,glucose and other sugars.Previous studies have shown thatSlSWEET14 is a specifically expressed gene in the fruit of tomato,which is involved in the transport of sugars,but its specific role is not clear.The promoter plays a key role in the regulation of gene expression,so the study of the biological function of the gene promoter and its cis acting elements is an important means to regulate gene expression.Based on Micro-Tom tomato(Solanum lycopersicum)as experimental material,SlSWEET14 gene promoter was cloned by conventional method PCR method,further through the 5 'end of deletion,by the combination of Gateway technology and pBGWFS7,0 fusion expression vector and expression of GUS gene driven,GUS histochemical staining analysis and GUS fluorescence quantitative analysis,determined specific promoter expression pattern,lay the foundation for a comprehensive exposition of the function of SlSWEET14 gene,and also provides the basis for the research and breeding of high quality varieties of tomato SWEETs gene family.The main results of this study are as follows:1,the promoter of SlSWEET14 bioinformatics analysis showed that SlSWEET14 gene promoter in higher plants contain common core promoter cis element TATA-BOX,CAAT-BOX,also contains the cis acting elements such as hormone response:salicylic acid cis element TCA-element,gibberellin response TATC-box cis element in response to auxin AuxRR-core cis element,in response to ethylene ERE cis element;stress-related cis elements such as:heat stress response cis element HSE,and induced by drought related cis acting element MBS;with the development of endosperm related cis elements Skn-1_motif and light;in response to the relevant cis acting element of GT1-motif,Box ?,Box4,AE-box etc..2,The transient expression activity of the promoter was analyzed by Agrobacterium tumefaciens-mediated fruit injection.The results of GUS histochemical staining and GUS fluorescence quantitative analysis showed that the length of the promoter was shorter after 3 days of fruit injection,The expression activity of GUS gene was gradually decreased.3,By analyzing the tissue-specific GUS staining of transgenic Arabidopsis thaliana,it was found that the three promoter fragments could drive the GUS gene to express in the Arabidopsis thorn fruit,but the shortest fragment drives the GUS gene in Arabidopsis thaliana and flower.There is also a large number of expression,that is,the shortest fragment of the promoter has lost tissue specificity and contains a cis-acting element that determines fruit-specific expression at-1466bp to-767bp upstream of the SlSWEET14 promoter.