Submitted by Ksenia Krasileva on
We aim to understand how plants can defend themselves against diseases. Plants have an immune system. When a pathogen attacks, plants detect its presence and trigger molecular signalling cascade inside the plant cell. Our comparative genomics analysis of plant immune genes across flowering plants, including model organisms and crops, highlighted candidate genes with distinct evolutionary patterns across both monocot and dicot species. To test the hypothesis that these genes are involved in disease resistance, we have devised a project to validate their role in disease resistance using model plant species, Arabidopsis thaliana and Nicotiana benthamiana.
Our special interest is proteins with Toll/Interleukin receptor (TIR) domain. The TIR domain proteins function both in animal and plant immunity, however their exact mode of action in plants is still unknown. We have uncovered TIR2 proteins of a novel class that are present in most plant species. We have cloned these genes from Amborella, Arabidopsisand maize for functional studies. When over-expressed in N. benthamiana, we observed that maize TIR2 protein was able to trigger immune response. We are currently examining overexpression phenotypes and mutant knockouts of these genes in Arabidopsis and will make CRISPR knockouts of these genes in other species. We are also making mutations in predicted catalytic sites to understand how TIR2 function in plants. In addition, we have conducted a yeast two hybrid screen and will follow up on their interacting plant proteins.
Our evolutionary analyses also predicted novel components of plant immunity. We are testing their function by overexpression in Arabidopsisand creating CRISPR knockouts in Arabidopsisand N. benthamiana. We will test the roles of our pathogen assays on the mutant/overexpression lines to test if altering these genes can lead to enhanced resistance or compromised immunity.
The undergraduate will help to design and make CRISPR constructs, plant Arabidopsis and tobacco, perform transient gene expression assays. The individual will have the opportunity to learn basic molecular biology techniques, including cloning, pathogen infection, plant immunity assays, with careful recording of data and basic statistical analysis where needed. The individual will present their results at lab meetings and discuss progress in weekly meetngs with their mentor. The individual will be part of our interdisciplinary lab and will also have opportunity to learn about evolutionary biology and computational approaches.
Student must be a 2nd year or above majoring in the biological sciences. We do not require previous research experience, but basic laboratory training is essential, including understanding of molarity calculations, serial dilutions. Good organization skills, attention to details and goo time management skills are essential. We expect student to dedicate 8-10 hours a week to the project, ideally in 2-4 hour blocks of time.