Publikationsserver der RWTH Aachen University
Investigations on the role of mitogen-activated protein kinases 11 and 17 in defense response of Arabidopsis thaliana
Abstract
dc:descriptionPriming of defense for a stronger and faster response to abiotic and biotic stress is an important part of acquired immunity in plants and animals. Recent findings revealed the involvement of the two mitogen-activated protein kinases MPK3 and MPK6 in the regulation of priming in Arabidopsis thaliana. Since the A. thaliana genome encodes 20 MPKs, I wondered, whether one or more of the other MPKs would be involved in priming. Bioinformatic analysis revealed a strong transcriptional upregulation of MPK11 upon treatment with the priming-inducing chemicals BTH, BABA, and salicylic acid, and upon several biotic and abiotic stress stimuli. In addition, I performed a phenotypic screen of mpk mutants that revealed strong morphological defects in mpk17 T-DNA knockout plants. To elucidate the potential role of MPK11 and MPK17 in plant defense, I treated mpk11 and mpk17 mutants with various plant pathogens and analyzed basal plant defense responses. Furthermore, I performed drought stress experiments to investigate one abiotic stress response in mpk11 and mpk17 mutants. I found that both mutants are not affected in their response against Pseudomonas syringae and the necrotrophic fungus Botrytis cinerea, whereas I could reveal a slight reduction in basal defense against the biotrophic oomycete Hyaloperonospora arabidopsidis. In addition, I showed that both mutants are not affected in the production of reactive oxygen species or in deposition of callose, two typical basal defense responses. Furthermore, by analysis of protein phosphorylation, I excluded a compensational effect of MPK3, MPK4, and MPK6, the major players in plant defense signaling, for the loss of mpk11 and mpk17. In all experiments, I did not see significant alterations in primed defense responses, suggesting that both kinases do, if at all, only play a minor role in plant defense. According to bioinformatic analysis, I propose a role for MPK17 in the regulation of developmental processes. Furthermore, I discuss a possible role of MPK11 as a backup system for other kinases.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2011
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Neumann, Martin
- Contributors dc:contributor
-
- Conrath, Uwe
Subjects
dc:subject × 8Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- eng