Dependence of Cellulase Induced Resistance to Alamethicin (CIRA) on Membrane Lipid Modification (s) in Arabidopsis thaliana
(2018) BIOP01 20162Degree Projects in Biology
- Abstract
- Fungi belonging to the genus Trichoderma are filamentous and soilborne, and are usually known for their plant growth-stimulating effects. Trichoderma viride is one of the species belonging to the genus, and is recognized as a plant symbiont known to improve plant growth and pathogen protection. Trichoderma species produce certain antifungal and antibiotic agents called peptaibols, as secondary metabolites. Alamethicin is a peptaibol produced by the fungus T. viride. Alamethicin has been a model peptide to study ion channel assembly, voltage gating, and peptide-membrane interactions. It is also widely used as an agent to induce various physiological and defense responses in plants and as a tool for cell permeabilization. Alamethicin forms... (More)
- Fungi belonging to the genus Trichoderma are filamentous and soilborne, and are usually known for their plant growth-stimulating effects. Trichoderma viride is one of the species belonging to the genus, and is recognized as a plant symbiont known to improve plant growth and pathogen protection. Trichoderma species produce certain antifungal and antibiotic agents called peptaibols, as secondary metabolites. Alamethicin is a peptaibol produced by the fungus T. viride. Alamethicin has been a model peptide to study ion channel assembly, voltage gating, and peptide-membrane interactions. It is also widely used as an agent to induce various physiological and defense responses in plants and as a tool for cell permeabilization. Alamethicin forms voltage-gated ion channels in the lipid bilayers of membranes including those of the host plant cells. However, pretreatment of plant cells with cellulase(s) produced by T. viride induces resistance to alamethicin permeabilization. Previous studies suggest that this resistance may be due to modifications in the lipid membrane constituents. The aim of this research project was to utilize Arabidopsis mutants to investigate the dependence of Cellulase Induced Resistance to Alamethicin (CIRA) on the plasma membrane lipid composition in Arabidopsis roots. Through this project, we preliminarily categorized 21 Arabidopsis mutants based on the gene types, gene families, protein location and gene expression using bioinformatics databases. Special emphasis was given on studying the psd3 mutants and to understand what proteins/pathways are involved in making this mutant deficient in CIRA. Through this research project, we categorized the CIRA mutant genes based on the proteins involved in lipid metabolic processes, Ca2+ signaling pathways and cell wall-related proteins, which suggests a potential mechanism for plant tolerance to Trichoderma needed for mutualistic symbiosis. (Less)
- Popular Abstract
- Trichoderma- a friend and foe!
The soil is a rich source of minerals and nutrients. It is the primary source of survival for plants, as well as other organisms. It is also rich in specific fungal species that have both beneficial and lethal effects on its habitat. Fungi interact with plants in various ways and each of these interactions lead to distinct modifications in both the partners. The fungal pathogen attack on plants results in damaging effects on the plant physiology as well as provides mutualistic benefits to the plants. They do so by helping the roots absorb nutrient from soil, and build resistance to biotic and abiotic stresses. Trichoderma is a type of filamentous and soil-borne fungi, and are usually known for their plant... (More) - Trichoderma- a friend and foe!
The soil is a rich source of minerals and nutrients. It is the primary source of survival for plants, as well as other organisms. It is also rich in specific fungal species that have both beneficial and lethal effects on its habitat. Fungi interact with plants in various ways and each of these interactions lead to distinct modifications in both the partners. The fungal pathogen attack on plants results in damaging effects on the plant physiology as well as provides mutualistic benefits to the plants. They do so by helping the roots absorb nutrient from soil, and build resistance to biotic and abiotic stresses. Trichoderma is a type of filamentous and soil-borne fungi, and are usually known for their plant growth-stimulating effects. Trichoderma viride is one of the species belonging to this genus and is recognized as a plant symbiont known to improve plant growth and pathogen protection. Trichoderma species produce certain antifungal and antibiotic pore-forming peptides, called peptaibols. These peptaibols are usually 7-20 amino acids in length and are known to possess antimicrobial activity against specific Gram-positive organisms. Alamethicin is a peptaibol produced by the fungus T. viride. It is widely used as an agent to induce various physiological and defense responses in plants and as a tool for cell permeabilization.
Alamethicin forms channels in the lipid bilayers of plasma membranes including those of the host plant cells leading to cellular leakage (Fig.1A). However, pretreatment of plant cells with cellulase (an enzyme that breaks down the cellulose found in plant cell walls into simple sugars) produced by T. viride, leads to cell wall alterations that induce plant resistance to the channel formation by alamethicin in the plant (Fig.1B).
The aim of this research was to utilize Arabidopsis thaliana mutants to investigate the dependence of Cellulase-Induced Resistance to Alamethicin (CIRA) in Arabidopsis roots. The research was directed towards acquiring more knowledge on the various proteins involved in CIRA, the type of signalling and membrane modifications occurring to induce resistance to alamethicin in Arabidopsis mutants.
Results
Through this study, we successfully confirmed that root tips of Arabidopsis thaliana wild type seedlings can be permeabilized by alamethicin and resistance to this permeabilization can be achieved upon pre-treatment with cellulase. Furthermore, we identified 21 Arabidopsis genes which do not show resistance to alamethicin permeabilization, after pre-treatment with cellulase.
Applications
The findings from this research can in the long run help to create artificial systems for increasing the yield of disease-free crop plants, independent of Trichoderma. In this artificial system, pre-treating the crop seeds with cellulase will build resistance to alamethicin. The plants will become resistant to alamethicin concentrations which are lethal to other pathogenic organisms in the soil.
Master’s Degree Project in Plant Science 60 credits 2018
Department of Biology, Lund University
Advisors: Allan Rasmusson and Bradley Dotson
Molecular Cell Biology Unit, Department of Biology (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8960334
- author
- Holla, Sanjana
- supervisor
- organization
- course
- BIOP01 20162
- year
- 2018
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 8960334
- date added to LUP
- 2018-10-16 14:16:01
- date last changed
- 2018-10-16 14:16:01
@misc{8960334,
abstract = {{Fungi belonging to the genus Trichoderma are filamentous and soilborne, and are usually known for their plant growth-stimulating effects. Trichoderma viride is one of the species belonging to the genus, and is recognized as a plant symbiont known to improve plant growth and pathogen protection. Trichoderma species produce certain antifungal and antibiotic agents called peptaibols, as secondary metabolites. Alamethicin is a peptaibol produced by the fungus T. viride. Alamethicin has been a model peptide to study ion channel assembly, voltage gating, and peptide-membrane interactions. It is also widely used as an agent to induce various physiological and defense responses in plants and as a tool for cell permeabilization. Alamethicin forms voltage-gated ion channels in the lipid bilayers of membranes including those of the host plant cells. However, pretreatment of plant cells with cellulase(s) produced by T. viride induces resistance to alamethicin permeabilization. Previous studies suggest that this resistance may be due to modifications in the lipid membrane constituents. The aim of this research project was to utilize Arabidopsis mutants to investigate the dependence of Cellulase Induced Resistance to Alamethicin (CIRA) on the plasma membrane lipid composition in Arabidopsis roots. Through this project, we preliminarily categorized 21 Arabidopsis mutants based on the gene types, gene families, protein location and gene expression using bioinformatics databases. Special emphasis was given on studying the psd3 mutants and to understand what proteins/pathways are involved in making this mutant deficient in CIRA. Through this research project, we categorized the CIRA mutant genes based on the proteins involved in lipid metabolic processes, Ca2+ signaling pathways and cell wall-related proteins, which suggests a potential mechanism for plant tolerance to Trichoderma needed for mutualistic symbiosis.}},
author = {{Holla, Sanjana}},
language = {{eng}},
note = {{Student Paper}},
title = {{Dependence of Cellulase Induced Resistance to Alamethicin (CIRA) on Membrane Lipid Modification (s) in Arabidopsis thaliana}},
year = {{2018}},
}