Cloning And Expression Analysis Of Granule-bound Starch Synthase Gene In Chinese Water Chestnut (Eleocharis Tuberosa)

Chinese water chestnut(Eleocharis tuberosa),a member of the family Cyperaceae Heleocharis,is a perennial aquatic herb,which is native to China and India.Starch,composed of amylose and amylopectin is the main storage nutrition in Chinese Water Chestnut.Amylose can be completely decomposed into maltose and a small amount of glucose,while amylopectin hydrolysis products are maltose,glucose,and a relatively large limit dextrin of molecular weight.Chinese water chestnut is popular,especially more soluble solids content,lower starch content,less slag and sweet.The Granule-bound starch synthase is widely considered as one of the most important enzymes in plant amylose synthesis.Therefore,in this study,the full-length of cDNA and genomic DNA of GBSS were isolated,and expression of this gene in different cultivars was also analyzed.1.The immature corn of Chinese water chestnut was chosen as material to extract the total RNA.Granule-bound starch synthase genes was isolated using RACE-PCR technique.The full-length cDNA of GBSS was 2 265 bp,containing an open reading frame,which was 1 818 bp encoding 605 amino acids and encoding a protein molecular weight of 66.5 kDa.2.DNA was extracted from immature corm of Chinese water chestnut,and DNA sequences of GBSS were amplified by PCR technology.The DNA sequence of GBSS was 4 578 bp,consisting of 13 exons and 12 introns.Among which,the first intron(504 bp)was the largest,and the seventh intron(83 bp)was the smallest;The first exon(532 bp)was the largest,and the fifth exon(64 bp)was the smallest,and there were five exons less than 100 bp.3.Expression profiling of Chinese water chestnut GBSS was analyzed using qPCR method.Expression of GBSS was detected as following tendency:corm>stolon>cladophyll>Point bud.The expression of GBSS in corms was significant higher than the expression of GBSS in other organs,and while these genes showed lower expression in both cladophyll and Point bud.The expression of GBSS showed a trend from rise to decline in both cultivar ’Hong bao shi’ and ’Su zhou bi qi’,and the expression of GBSS in cultivar ’Hong bao shi’ was higher than in cultivar ’Su zhou bi qi’ in the process of corm development.The expression of GBSS in corms had the highest mRNA level in the later period of corm and the lowest mRNA level in stolons.