Use of GWAS to elucidate temperature-modulated disease resistance in Arabidopsis thaliana
Rising temperatures due to climate change are causing increased disease incidence on some crop plants. However, plants may have adapted sophisticated mechanisms for survival in fluctuating environments: enduring constant changes in light, humidity and temperature, and maintaining resistance to pathogens. It is thus possible to identify the underlying adaptation mechanism using natural distributed strains as materials. To begin to investigate this temperature-resistance relationship, and detect causal genes, Arabidopsis thaliana natural variations whose genome has been sequenced/mapped were employed. The Arabidopsis plants grown at three ambient temperatures were inoculated with the pathogen Pseudomonas syringae var. DC3000 (Pst DC3000), a model pathogen used successfully for Arabidopsis-pathogen interaction assay, and their propagation in the plant was determined. This allowed us to associate their single-nucleotide polymorphisms (SNP) with resistance ability. This interaction between temperature sensing genes and the genes responsible for plant resistance was detected through Genome Wide Association Study (GWAS) screening. GWAS screening for resistance in the 28°C test group was completed, and several interesting candidate genes popped up. It is hoped that if these genes are indeed confirmed as temperature sensitive resistance genes, they may be useful in plant breeding to develop heat and disease resistant crops.
I felt that this summer gave me a different perspective on how research is conducted, and increased my exposure to different research environments. I learned how to persevere and maintain motivation during a long and high intensity, high throughput experiment, such as those done for GWAS. Learning how to work with Arabidopsis was also a new experience for me as I had previously worked with crop plants. My abilities to troubleshoot and problem solve were also exercised, as my mentor and I figured out different ways to perform the necessary parts of the pathogen assay we were performing. I greatly appreciated my mentor’s support of my project, and the perspective he was able to lend me about his own research experience. I also enjoyed the opportunity that I got to begin to manage my lab work and perform research independently as the summer progressed. I also appreciated the Wednesday seminars, and felt that they gave me a valuable overview about what other researchers at BTI and Cornell University were discovering.