Computational analysis of upstream regulatory elements regulating plant chlorophyll degradation
type: CreativeWork
description: "Chlorophyll is a vital compound in photosynthesis in plants and as such both its biosynthesis and degradation are tightly regulated. Disruption of the regulatory pathway for chlorophyll breakdown by exposure to cold temperature episodes in canola seed is the basis of the economically significant ""green seed problem"". A major controlling step in the chlorophyll degradation pathway involves the enzyme pheophorbide a oxygenase (PAO), which oxidizes the chlorophyll degradation intermediate pheide a, that is eventually converted to non-fluorescent chlorophyll catabolites (NCCs). PAO activation in maturing green seeds is known to be disrupted following freezing episodes, but the exact mechanism for this is not known. There is evidence that PAO is both transcriptionally and post transcriptionally regulated but the components involved are uncertain or unknown. First, it was hypothesized that freeze exposure will affect the expression of upstream regulatory elements, leading to modulation of PAO expression and/or PAO regulators that ultimately will slow chlorophyll degradation resulting in incomplete chlorophyll clearing of mature canola seeds. The second hypothesis was that the leaf senescence process will alter the normal expression profiles of upstream regulatory elements, leading to modulation of PAO expression that ultimately will stimulate chlorophyll degradation. Third, it was hypothesized that drought will affect upstream regulatory element expression, leading to modulation of PAO expression that ultimately will stimulate chlorophyll degradation, since cold and drought are known to share components of their upstream regulons. The goal of this research was to significantly advance our understanding of the regulation of PAO activity and in turn provide important insights into strategies to mitigate the economic impact of the canola green seed problem. To test these hypotheses, several sets of genomic and bioinformatics experiments were investigated and re-analyzed u…
abstract: "Chlorophyll is a vital compound in photosynthesis in plants and as such both its biosynthesis and degradation are tightly regulated. Disruption of the regulatory pathway for chlorophyll breakdown by exposure to cold temperature episodes in canola seed is the basis of the economically significant ""green seed problem"". A major controlling step in the chlorophyll degradation pathway involves the enzyme pheophorbide a oxygenase (PAO), which oxidizes the chlorophyll degradation intermediate pheide a, that is eventually converted to non-fluorescent chlorophyll catabolites (NCCs). PAO activation in maturing green seeds is known to be disrupted following freezing episodes, but the exact mechanism for this is not known. There is evidence that PAO is both transcriptionally and post transcriptionally regulated but the components involved are uncertain or unknown. First, it was hypothesized that freeze exposure will affect the expression of upstream regulatory elements, leading to modulation of PAO expression and/or PAO regulators that ultimately will slow chlorophyll degradation resulting in incomplete chlorophyll clearing of mature canola seeds. The second hypothesis was that the leaf senescence process will alter the normal expression profiles of upstream regulatory elements, leading to modulation of PAO expression that ultimately will stimulate chlorophyll degradation. Third, it was hypothesized that drought will affect upstream regulatory element expression, leading to modulation of PAO expression that ultimately will stimulate chlorophyll degradation, since cold and drought are known to share components of their upstream regulons. The goal of this research was to significantly advance our understanding of the regulation of PAO activity and in turn provide important insights into strategies to mitigate the economic impact of the canola green seed problem. To test these hypotheses, several sets of genomic and bioinformatics experiments were investigated and re-analyzed u…
author: Ghandchi, Frederick Pejman
language: en
keywords: Genomics, Data Science, Data Engineering, Data Analysis, Computational Analysis, Statistical Programming, Database Development, Statistical Modeling
date published: 2016-11-10T17:49:45Z
date modified: 2026-07-22T22:26:35Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/92716