Understanding the Role of Farnesylation During the Cross-talk Between Brassinosteroids and Abscisic Acid Responses

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atmire.migration.oldid5206
dc.contributor.advisorSamuel, Marcus Jr
dc.contributor.authorLiang, Siyu Jr
dc.contributor.committeememberChua, Gordon Jr
dc.contributor.committeememberRo, Dae-Kyun Jr
dc.contributor.committeememberGrowl, Savraj Jr
dc.contributor.committeememberNambara, Eiji Jr
dc.date.accessioned2017-01-10T22:12:25Z
dc.date.available2017-01-10T22:12:25Z
dc.date.issued2016
dc.date.submitted2016en
dc.description.abstractProtein farnesylation is a post-translational modification involving the addition of a 15-carbon farnesyl isoprenoid to the carboxy terminus of select proteins. Although the roles of this lipid modification are clear in both fungal and animal signaling, many of the mechanistic functions of farnesylation in plant signaling are still unknown. In this study, I show that CYP85A2, the cytochrome P450 enzyme that performs the last step in brassinosteroid (BR) biosynthesis (conversion of castasterone to brassinolide (BL)), must be farnesylated to function in Arabidopsis. Loss of either CYP85A2 or CYP85A2 farnesylation results in reduced BL accumulation and increased plant responsiveness to the hormone abscisic acid (ABA) and overall drought tolerance. Further characterization of cyp85a2-2 mutants, suggested that lack of BL resulted in enhanced constitutive ABA signaling independent of ABA biosynthesis, indicating a role for BL in suppressing ABA signaling. I further showed through epistatic analysis that the farnesyltransferase, ERA1, also plays a role downstream of BZR1, the BR-induced transcription factor, in mediating the skotomorphogenic (dark response during seedling development) response. This study has unveiled previously unknown links between farnesylation and brassinosteroid biosynthesis that could lead to new strategies to maintain crop yield under challenging climatic conditions.en_US
dc.identifier.citationLiang, S. J. (2016). Understanding the Role of Farnesylation During the Cross-talk Between Brassinosteroids and Abscisic Acid Responses (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/28573en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/28573
dc.identifier.urihttp://hdl.handle.net/11023/3553
dc.language.isoeng
dc.publisher.facultyGraduate Studies
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.placeCalgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectBotany
dc.subjectBiology--Molecular
dc.subjectPlant Physiology
dc.subject.classificationfarnesylationen_US
dc.subject.classificationbrassinosteroidsen_US
dc.subject.classificationAbscisic Aciden_US
dc.titleUnderstanding the Role of Farnesylation During the Cross-talk Between Brassinosteroids and Abscisic Acid Responses
dc.typedoctoral thesis
thesis.degree.disciplineBiological Sciences
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameDoctor of Philosophy (PhD)
ucalgary.item.requestcopytrue
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