海岛棉脂肪酶基因gbeds1抗黄萎病功能及分子机制作物遗传育种专业论文.docxVIP

Functional Functional and molecular mechanism of lipase gene GbEDSl from Gossypium barbadense to Verticillium wilt Author：Rong Wei Major：Crop Genetics and Breeding Supervisor：．Associate Prof．Li Zhi—kun Prof．Ma Zhi-ying Abstract Cotton(Gossypium spp．)is one of the most important economic crops worldwide， providing fiber and oil．Vertieillium wilt is one of the destructive diseases associated with cotton，causing severe losses both in cotton yield and fiber quality．Mining and understanding the functional mechanisms of genes related to resistance against形dahliae will benefit efforts to genetically improve crop plants．By screening cDNA libraries of Gossypium barbadense induced by”dahliae，a gene homologous of EDSl(Enhanced D括ease Susceptibilityl)was isolated，named GbEDSl．However,the function of GbEDSl in cotton and its molecular mechanism in defense against矿dahliae remain unclear．In this study,the main contents were shown as follows：(1)Using T4 transgenic Arabidopsis as materials，evaluation of the effect on response toⅣdahliae infection，and dissection the mechanism at the level of molecular biology,cytology and physiological biochemistry． (2)Virus—induced gene silencing(VIGS)expression vector will be employed to transform cotton and silence endogenous EDSl gene of G hirsutum，assessment of the effect on response toⅣdahliae infection and the changes of related substrates and products in silenced cotton；mine cotton metabolic pathways that the EDSl participates in by detecting expression of some marker genes．The main results were summarized as follows： 、．GbEDS l was more closely related to GrEDSl t99％identity、)than to GhEDSl t98％ identity)or GaEDSl(97％identity)．Diverse cis—acting promoter elements，such as involving in defense response，hormone，drought·response，oxidation resistance，were discovered in the upstream region of GbEDSl． 2．Typical symptoms of vascular disease became apparent in the infected wild—type Col一0 plants but were much less pronounced in GbEDSl一overexpressing