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The capacity of Arabidopsis thaliana seedlings to develop resistance against alamethicin

Bakhshandeh, Maryam (2013) MOBM01 20131
Degree Projects in Molecular Biology
Abstract
Abstract

Previous research on tobacco and Arabidopsis cell suspensions have shown that plants can be permeabilized by the membrane-active peptide, alamethicin. However, pretreatment of cells with cellulase produced by the fungus Trichoderma viride induced resistance to alamethicin. In this project, I investigated the effect of alamethicin treatment on Arabidopsis thaliana seedlings and whether a pretreatment with cellulase would induce resistance to alamethicin also in this material.
To do so, I first examined whether resistance to alamethicin was related to age of A. thaliana seedling using the fluorescent propidium iodide as probe. However, I could not observe consistent age-dependent relations, and this approach was abandoned. Then,... (More)
Abstract

Previous research on tobacco and Arabidopsis cell suspensions have shown that plants can be permeabilized by the membrane-active peptide, alamethicin. However, pretreatment of cells with cellulase produced by the fungus Trichoderma viride induced resistance to alamethicin. In this project, I investigated the effect of alamethicin treatment on Arabidopsis thaliana seedlings and whether a pretreatment with cellulase would induce resistance to alamethicin also in this material.
To do so, I first examined whether resistance to alamethicin was related to age of A. thaliana seedling using the fluorescent propidium iodide as probe. However, I could not observe consistent age-dependent relations, and this approach was abandoned. Then, I developed a quantitative assay on A. thaliana seedlings. In this assay, I measured the activity of cytosolic NADP-isocitrate dehydrogenase which becomes accessible in the presence of alamethicin to form NADPH. My results showed that permeabilization increases by increasing alamethicin concentration. Pre-treatment of seedlings with cellulase resulted in seedlings that were slightly less permeabilized in comparison with control seedlings.

Popular science summary:

Resistance against alamethicin in Arabidopsis thaliana seedlings


Trichoderma species are usually non-pathogenic symbiotic fungi found mostly in soil. They have evolved mechanisms for both activating plant defence mechanism and for enhancing plant and root growth. As a result, they are widely used as biocontrol agents. Alamethicin is a peptaibol (a subgroup of antimicrobial peptides) produced by T. viride. When four to six peptide molecules aggregate together, they incorporate into membrane and form ion-channels. Permeabilization induces signals and defence-like responses in Arabidopsis just similar to hypersensitive response to pathogen attack. Previous research on tobacco and Arabidopsis cell suspensions have shown that pretreatment of cells with cellulase produced by the fungus T. viride induced resistance to alamethicin. In this project, I investigated whether permeabilization was dependant on A. thaliana seedlings age and whether a pretreatment with cellulase would induce resistance to alamethicin.
I examined the relation of resistance to alamethicin with A. thaliana seedling’s age by using the fluorescent propidium iodide as probe. However, I could not observe consistent age-dependent relations, and this approach was abandoned. Then, I developed a quantitative assay on A. thaliana seedlings. In this assay, I measured the activity of cytosolic NADP-isocitrate dehydrogenase which becomes accessible in the presence of alamethicin to form NADPH. My results showed that permeabilization increases by increasing alamethicin concentration. And pre-treatment of seedlings with cellulase resulted in seedlings that were slightly less permeabilized in comparison with control seedlings




Advisors: Susanne Widell and Allan G. Rasmusson
Master’s Degree Project in Molecular Biology, 30 credits
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Bakhshandeh, Maryam
supervisor
organization
course
MOBM01 20131
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
3810181
date added to LUP
2013-06-11 10:59:50
date last changed
2013-06-11 10:59:50
@misc{3810181,
  abstract     = {Abstract

Previous research on tobacco and Arabidopsis cell suspensions have shown that plants can be permeabilized by the membrane-active peptide, alamethicin. However, pretreatment of cells with cellulase produced by the fungus Trichoderma viride induced resistance to alamethicin. In this project, I investigated the effect of alamethicin treatment on Arabidopsis thaliana seedlings and whether a pretreatment with cellulase would induce resistance to alamethicin also in this material.
To do so, I first examined whether resistance to alamethicin was related to age of A. thaliana seedling using the fluorescent propidium iodide as probe. However, I could not observe consistent age-dependent relations, and this approach was abandoned. Then, I developed a quantitative assay on A. thaliana seedlings. In this assay, I measured the activity of cytosolic NADP-isocitrate dehydrogenase which becomes accessible in the presence of alamethicin to form NADPH. My results showed that permeabilization increases by increasing alamethicin concentration. Pre-treatment of seedlings with cellulase resulted in seedlings that were slightly less permeabilized in comparison with control seedlings.

Popular science summary:

Resistance against alamethicin in Arabidopsis thaliana seedlings 


Trichoderma species are usually non-pathogenic symbiotic fungi found mostly in soil. They have evolved mechanisms for both activating plant defence mechanism and for enhancing plant and root growth. As a result, they are widely used as biocontrol agents. Alamethicin is a peptaibol (a subgroup of antimicrobial peptides) produced by T. viride. When four to six peptide molecules aggregate together, they incorporate into membrane and form ion-channels. Permeabilization induces signals and defence-like responses in Arabidopsis just similar to hypersensitive response to pathogen attack. Previous research on tobacco and Arabidopsis cell suspensions have shown that pretreatment of cells with cellulase produced by the fungus T. viride induced resistance to alamethicin. In this project, I investigated whether permeabilization was dependant on A. thaliana seedlings age and whether a pretreatment with cellulase would induce resistance to alamethicin. 
 I examined the relation of resistance to alamethicin with A. thaliana seedling’s age by using the fluorescent propidium iodide as probe. However, I could not observe consistent age-dependent relations, and this approach was abandoned. Then, I developed a quantitative assay on A. thaliana seedlings. In this assay, I measured the activity of cytosolic NADP-isocitrate dehydrogenase which becomes accessible in the presence of alamethicin to form NADPH. My results showed that permeabilization increases by increasing alamethicin concentration. And pre-treatment of seedlings with cellulase resulted in seedlings that were slightly less permeabilized in comparison with control seedlings




Advisors: Susanne Widell and Allan G. Rasmusson
Master’s Degree Project in Molecular Biology, 30 credits
Department of Biology, Lund University},
  author       = {Bakhshandeh, Maryam},
  language     = {eng},
  note         = {Student Paper},
  title        = {The capacity of Arabidopsis thaliana seedlings to develop resistance against alamethicin},
  year         = {2013},
}