Elucidation of Jasmonate-Responsive Promoter Elements in the Calmodulin-Like Gene CML39 in Arabidopsis

All organisms require rapid and flexible signaling mechanisms in order to effectively respond to biotic and abiotic stress. Calcium ions (Ca2+) have proven to be important components of signaling networks. Observations of stimulus-specific oscillations of cytosolic Ca2+ during signal transduction suggest that Ca2+ signals directly encode information. These stimulus-specific oscillations, known as Ca2+ signatures, can be interpreted by an array of Ca2+-binding sensors and effectors, which subsequently regulate appropriate cellular responses. While progress has been made regarding the classic Ca2+-sensor calmodulin (CaM), less research has been directed towards the CaM-like family of Ca2+-sensors (CMLs). This family – unique to plants – is suspected to regulate a multitude of stress and developmental pathways; however, to date very few members of this family have had their functions elucidated by the identification of downstream targets and upstream regulators. In the present study, I investigate the regulation of CML39, which has previously been shown to strongly respond to the stress hormone jasmonic acid (JA) in Arabidopsis. Bioinformatic tools predict a large number of putative JA-responsive cis-elements within the CML39 promoter. Deletion analysis of CML39 promoter fragments in planta reveals that some cis-elements respond in a tissue-specific manner. Analysis of transgenic MYC2 loss-of-function (myc2) mutants demonstrates that MYC2 – the preeminent JA-responsive transcription factor – is not necessary for CML39 promoter activity. Collectively, these data reveal a complex tissue-specific pattern of CML39 regulation and provide a foundation for the future identification of relevant transcription factors.

Department dc:contributor.department

Biology

Year dc:date.issued

2013

Author dc:creator

• Maj, David

Advisor dc:contributor.supervisor

• Snedden, Wayne A.

• Calcium Signaling
• Calmodulin-Like
• Cis-Element
• Promoter
• Jasmonic Acid

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1974/8330

OAI identifier oai:identifier

oai:queensu.scholaris.ca:1974/8330