Date of Graduation

Summer 2011

Degree

Master of Science in Plant Science (Agriculture)

Department

College of Agriculture

Committee Chair

Wenping Qiu

Keywords

grapevine, stilbene synthase, powdery mildew, berry development, qPCR, HPLC

Subject Categories

Plant Sciences

Abstract

Stilbenic compounds have antimicrobial activities and some of them including resveratrol are beneficial to human health. Stilbene synthase (STS) is the key enzyme that catalyzes the biosynthesis of stilbenic compounds. There are 43 STS genes that are predicted on the sequenced grapevine genome PN40024, and the regulation of each STS gene needs to be understood for defining their biological roles. In this study, we selected four STS genes and employed quantitative polymerase chain reaction (qPCR) to characterize their transcriptional profiles during the berry development and infection by the powdery mildew fungus (PM), Erysiphe necator (Schw.) Burr., in Vitis vinifera 'Cabernet Sauvignon' and Vitis aestivalis 'Norton'. We found that transcript levels of these STS genes increased along with berry development largely post veraison both in Cabernet Sauvignon and Norton. Trans-resveratrol was also extracted from berry skin and quantified by high performance liquid chromatography (HPLC). The content of trans-resveratrol increased rapidly post veraison and reached the highest level at harvest. In response to PM infection, STS genes were up-regulated in Cabernet Sauvignon leaves while almost no change in Norton. These results demonstrated that each STS gene plays a special role in the berry development and in the defense against fungal infection. Furthermore, we cloned the promoter of three STS genes and one chalcone synthase -like gene and transferred them into Arabidopsis to analyze their functions.

Copyright

© Ru not applicable Dai

Campus Only

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