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The Role of Anthocyanins and The GATA Transcription Factors GNC and CGA1 in The Plant Response to Stress

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Title: The Role of Anthocyanins and The GATA Transcription Factors GNC and CGA1 in The Plant Response to Stress
Author: Xu, Zhenhua
Department: Department of Molecular and Cellular Biology
Program: Molecular and Cellular Biology
Advisor: Rothstein, Steven
Abstract: World-wide crop production is significantly affected by various abiotic and biotic stresses. Research on plant stress signalling and the resulting physiological response can provide insights into the development of crop cultivars with improved stress tolerance. In the current work, the role of anthocyanins in plant response to reactive oxygen species (ROS), high light and cold stress is investigated. In addition, the global putative targets of two GATA transcription factors, CGA1 and GNC, known to modulate the chlorophyll content and natural senescence process in response to different environmental conditions is investigated. Anthocyanins are a class of secondary metabolites which in food have been shown to have antioxidant activity and thus potentially be beneficial for human health when present in sufficient quantities. First, the antioxidant role of anthocyanins in plant stress response is analysed. Ten Arabidopsis anthocyanin mutants, with varying levels of anthocyanin content, which are in the main regulatory and biosynthetic genes of the anthocyanin pathway were utilized. Their physiological, molecular and cellular responses were analysed under ROS, high light and cold stress. The data shows that ROS is an important signal to trigger the accumulation of anthocyanins, and in turn anthocyanins function as an antioxidant to buffer ROS homeostasis and provide protection against the cellular damage caused by ROS. GNC and CGA1 are two GATA transcription factors that play important roles in chlorophyll accumulation, flowering, hormone signalling and natural senescence as well as in the plant response to nutrient stress. We utilized a genome-wide ChIP-Seq technique in Arabidopsis to discover the putative target genes of CGA1 and GNC and revealed the possible downstream genes controlling chlorophyll content and the natural senescence process. In addition, the pleotropic functions of rice OsGNC were explored through analysing the rice OsGNC transgenic lines, suggesting the functional conservation of GNC and CGA1 across plant species. This study expanded the current knowledge of abiotic stress response in plants and hopefully this information can be applied for future crop improvement.
Date: 2016-05
Rights: Attribution-NonCommercial-NoDerivs 2.5 Canada
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Attribution-NonCommercial-NoDerivs 2.5 Canada Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivs 2.5 Canada