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Proteomic analysis of environmental stress responses in grapevine

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thesis
posted on 28.03.2022, 17:07 authored by Iniga Seraphina George
Understanding environmental stress responses is essential to improve abiotic stress tolerance in commercially important crops such as grapevine. Erratic abiotic stresses can pose a threat to viticulture practices. Changes in temperature and light exposure, either suddenly or seasonally, are crucial environmental factors that can influence grapevine productivity. The grape genome sequence was released in 2007 and the availability of this genomic information facilitated proteomic investigations to be executed in the Vitis species with ease. In this thesis, we aimed to enhance our understanding on biological pathways activated by the impact of abiotic stresses in grapevine, by characterising proteins associated with stress responses. Firstly, we optimised a sample preparation and fractionation methodology for label-free quantitative shotgun proteomic analysis of grapevine. We then implemented this optimised protocol for all the studies included in this thesis. Subsequently, we examined the influence of thermal stresses on Vitis vinifera and compared protein expression patterns between the control temperature and two different heat and cold stresses. This is the first label-free shotgun proteomic study on grape exposed sudden temperature changes. We demonstrated that proteins involved in phenylpropanoid biosynthesis were more abundant at extreme cold stress and could be cold-responsive proteins. We also observed that sugar metabolism switched between the alternative and classical pathways at thermal stresses. Next, two hybrid grapevine species - Vitis riparia and Seyval, were used to investigate cellular mechanisms associated with photoperiod regulated biological processes of growth cessation and dormancy induction. Several enzymes involved in glycolysis, and dormancy induction were up-regulated in short daylength buds compared to long daylength buds. We observed active growth as well as greater abundance of phenylpropanoid biosynthesis proteins in long daylength buds. Finally, we have introduced a new method for validation of quantitative shotgun proteomic data. We developed a protein quantitation false discovery rate and applied it as a noise-level threshold, to establish the significance of the proteomic results in this thesis. All the research studies in this thesis demonstrated the efficacy of label-free proteomics approaches in gaining information on grapevine responses to environmental stresses at the cellular level.

History

Table of Contents

1. Introduction -- 2. Materials and methods -- 3. Protein identification and quantification from riverbank grape, Vitis riparia: comparing SDS-PAGE and FASP-GPF techniques for shotgun proteomic analysis -- 4. Quantitative proteomic analysis of Cabernet Sauvignon grape cells exposed to thermal stresses reveals alterations in sugar and phenylpropanoid metabolism -- 5. Shotgun proteomic analysis of photoperiod regulated dormancy induction in grapevine -- 6. A new approach for validation: measurement of protein-fold changes by spectral counting to determine protein quantification false discovery rates -- 7. Conclusions and future directions -- Appendix.

Notes

Includes bibliographical references Thesis by publication.

Awarding Institution

Macquarie University

Degree Type

Thesis PhD

Degree

PhD, Macquarie University, Faculty of Science and Engineering, Department of Chemistry and Biomolecular Sciences

Department, Centre or School

Department of Chemistry and Biomolecular Sciences

Year of Award

2015

Principal Supervisor

Paul Haynes

Rights

Copyright Iniga Seraphina George 2015 Copyright disclaimer: http://mq.edu.au/library/copyright

Language

English

Extent

1 online resource (224 pages) illustrations

Former Identifiers

mq:55576 http://hdl.handle.net/1959.14/1150587