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Study on Promoter Function of Glycosyltransferase Gene Sm-Ngt1 from Tabacco and Its Over-expression in Arabidopsis Thaliana

Author: ShangShuFeng
Tutor: LiuXueQun
School: Central South University for Nationalities
Course: Biochemistry and Molecular Biology
Keywords: Tabacco glycosyltransferase Arabidopsis thaliana (col) promoter salylic acid jasmonic acid
CLC: Q943.2
Type: Master's thesis
Year: 2009
Downloads: 92
Quote: 1
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Abstract

Glycosytransferases (GTs) transfer a sugar from an activated sugar donor to a specific acceptor molecule to form glucosidic bond. GTs was a super-family. GTs are classified into 91 sub-families according to the specificity of substrate, sequence relatedness and the stereochemistry of glycosidic linkage. Glycosylation was related with many physiological-biochemical reactions. GTs plays an important role in glycosylation, mediating the process such as regulating activities and homeostasis of signal molecule and hormone, and processes of the resistance response to different stresses.A novel sm-Ngt1 gene cloned in this laboratory early, whose expression was dually induced by MeJA and SA. CaMV 35S promoter was substituted by the deletion mutations of the sm-Ngt1promoter in pCAMBIA1301vector, and deletion mutations plasmids pGTPA, pGTPB, pGTPC, pGTPD and pGTPE were constructed. The results suggest the pGTPB with -800~-1 of sm-Ngt1 promoter sequence could be induced by SA and MeJA and pGTPC with -600 ~ -1 of sm-Ngt1 promoter sequence was a constitutively expressed in their transgenic tobacco plants. The over expression sm-Ngt1 resulted in the phenotypic variation such as larger leaf vein and dwarf in the transgenic tobacco plants. In this study, Arabidopsis thaliana (Columbia ecotype, col) were transformed with pGTPB and pGTPC by dip-method mediated by Agrobacterium tumefacien. The GUS activities of pGTPB and pGTPC in the transgenic Arabidopsis plants were analysized. And the effect of sm-Ngt1over expression on growth and development of Arabidopsis was also researched. The resuits are as follows.1. Arabidopsis thaliana(col) was transformed with pGTPB by dip-flower method mediated by Agrobacterium tumefacien and Many transgenic plants were obtained by both hygromycin selection and PCR identification with special primer. In the 30 transgenic plants treated by H2O, SA and MeJA, respectively, the 16 SA and MJA treated transgenic plants had much higher GUS activities than that of control (H2O treated) in the leaves; 3 of them were induced by SA, but were inhibited by MeJA; 6 of them were dually inhibited by SA and MeJA. And the RNA expression analysis with realtime-PCR in 8 of transgenic plants showed that the changes of GUS activity were consistent with that of gus RNA expression. Histochemical staining showed that gus was expressed in root, stem, leaf and flower, but strongest expression in the vascular tissues.2. In the transgenic Arabidopsis plants with pGTPC, the GUS activity was basically higher than those of pGTPB transformed plants.3. In the transgenic plants transformed with sm-Ngt1over expressed vector, some dwarf plants were presented, of which thicker leaf vein was than the wild type, the shorter and thicker petiole, and smaller and intensive glandular hair than the wild type were observed.

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