Document Type

Thesis - University Access Only

Award Date

2011

Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology

Abstract

Drought has become an increasingly important constraint on grapevine growth and development due to global climate change. Vitis riparia, the only grapevine native to the upper Midwest region of the United States, is widely used in scion and rootstock breeding; however, it is not considered drought tolerant. Studying differential gene expression of V. riparia root vascular cells and whole grapevine responses to water deficit will improve management practices, enhance breeding techniques, help elucidate the abscisic acid (ABA) pathway, and lend greater insight into the grapevine root transcriptome. One group of V. riparia vines underwent water stress (water deficit) for 14 days by withholding water, while another group received water daily (control). Vine growth, single leaf gas exchange, tissue weight, soil water potential, and stem water potential were recorded throughout the study. Mature leaf abscission, morphological root changes, growth cessation, and carbon distribution suggest that V. riparia allocates its limited resources during water deficit to maintain turgor in the apex of the grapevine shoot tip and to sustain root growth. At the end of the water deficit study roots were collected for vascular cylinder tissue laser capture microdissection (LCM) and roots and shoot tips were collected for whole tissue RNA extraction. RNA-Sequencing (RNA-Seq) data analysis of root vascular cells revealed that over 6000 genes were differentially expressed under water deficit, 42 of which are components of the ABA metabolic pathway. Real-time PCR (RT-PCR) analysis of seven ABA pathway genes in whole root and shoot tissue showed a strong correlation (0.7840) between RT-PCR and RNA-Seq results. Overall, expression of ABA biosynthesis genes increased during water deficit in roots relative to shoot tips.

Library of Congress Subject Headings

Grapes -- Drought tolerance

Grapes -- Effect of stress on

Grapes -- Genetics

Format

application/pdf

Number of Pages

113

Publisher

South Dakota State University

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