Tyseen Murad
Year: 2021
Faculty Advisor: Clare Casteel

“Plant Defenses Downstream of MEDIATOR SUBUNIT 16 Regulates Plant Resistance to Turnip mosaic virus and its Aphid Vector Myzus persicae

Project Summary:

Currently, Turnip mosaic virus (TuMV) is one of the most destructive viruses to vegetable crops worldwide. They are transmitted non-persistently through at least 89 aphid species, including the green peach aphid (Myzus persicae). Being able to understand these aphid-virus interactions could be key in developing pest management techniques to increase crop yield. Previous research suggests that the viral protease NIa-Pro, encoded by TuMV, manipulates the physiology of host plants to attract aphid vectors and promote their reproduction (Casteel et al. 2014). A bioinformatics screening was done to see whether NIa-Pro’s cleavage sites are present in any plant proteins. Of the several hundred plant proteins that were found to have a NIa-Pro cleavage site, MEDIATOR SUBUNIT16 (MED16) was one of them (Ray et al. in prep). MEDIATOR SUBUNIT16 (MED16) is a key regulator of the crosstalk between the Jasmonic acid and ethylene-dependent plant defense pathways. Investigating how the virus may affect this crucial protein can provide insight to how we can increase plant resistance to such viruses. Over the summer, I have worked at the Casteel Lab with my mentor Dr. Swayamjit Ray to explore how MED16 can regulate plant resistance to Turnip Mosaic virus and its aphid vector Myzus persicae. We found that TuMV infections increased MED16 transcripts in Arabidopsis thaliana and the virus also increased the amount of MED16 protein in plants and a possible cleaved product of the protein. Virus and aphid bioassays in med16 mutant plants further imply that MED16 is required for TuMV and aphid resistance. Moving forward, the Casteel lab will do further experimentation to confirm that NIa-Pro is the viral protease effector that cleaves plant MED16 causing the increase in aphid fecundity and virus performance in plants.

My Experience:

The Plant Genome Research Program provided me the opportunity to work and learn from an amazing batch of educators and scientists. Over the summer I learned many new research and lab techniques and was able to strengthen my critical thinking skills in order to troubleshoot. I also learned how to communicate and work effectively in a team with my mentor, PI, and other members of the lab. This experience provided a lot of exposure to a research team environment helping me clarify that it is something that I may want to do in the future. I also gained a lot of insight to the different niches in plant biology and how interdisciplinary it is! Moving forward, I feel more prepared and confident with engaging in scientific discourse as well as conducting research in a lab setting!