My project investigates important genes in plant defense against pathogens and how they have evolved. While human systems are extensively studied, plant defense mechanisms are more elusive. My project focused on the human Toll-like receptor (TLR) signaling pathway, which is crucial in the innate immune response and is well-documented, and its counterpart in plants, a class of receptors known as receptor-like kinases (RLKs). Literature describes the function and components of the TLR pathway, including Interleukin-1 receptor-associated kinase (IRAK), which mediates the innate immune response and is crucial in the human immune system (Picard et al., 2011). Similarly, in Drosophila, Pelle has defense roles and is an animal ortholog to RLKs (Shiu et al., 2004). Both TLRs and RLKs have a variable extracellular domain with LRRs, a transmembrane domain, and an intercellular signaling domain. I theorized that due to similarities in function and structure, and downstream components, TLRs and RLKs may have other functional correlations and similar evolutionary histories. To this end, I gathered scientific literature on TLR and RLK signaling and similarities between both pathways. By analyzing evolutionary history and function of the well-studied TLR signaling pathway and comparing it to that of RLKs in plants, my final written analysis, to be completed in the academic year, will reveal similarities and differences between the two pathways and the evolution of signaling genes in plants and animals. By applying TLR function findings to less-described RLK signaling, I aim to provide a broader understanding of defense mechanisms in plants. These findings can be used to improve crop defense and reduce crop loss to any number of pathogens that both TLR and RLK signaling pathways defend against - for example bacteria, fungi, and viruses.
Over the summer, I investigated this topic by accessing and reading literature regarding TLR signaling, LRR-RLK signaling, and the connection between the two. By collecting copious literature to better understand both mechanisms, as well as literature that drew tentative comparisons between the two, I gained a more complete understanding of how these pathways evolved and function today. With these collected resources, I will be able to create a comprehensive comparative analysis of the evolutionary histories and mechanisms of TLR and LRR-RLK signaling, and leverage research done on TLR signaling to LRR-RLK signaling in plants. Additionally, as I have found extensive literature describing the function and mechanisms of TLR signaling, I look to use this literature to draw conclusions about less-elucidated LRR-RLK signaling.
In the future, I would like to pursue a degree in immunology, and work in the field of mammalian immunology. My summer research regarding TLRs will be immensely helpful in my future studies, as TLRs play a crucial role in mounting the immune response. Similarly, my understanding of plant defense systems such as LRR-RLK signaling will give me a unique perspective when considering the mechanisms of the human immune system, and how to design drugs to work within those mechanisms.
The ability to access, understand, and analyze literature is vital to any scientific career. I am certain that my future studies, and eventual future career, will require me to read literature, in order to learn more about current techniques and findings, and to eventually plan my own experiments based on the work of others. My work this summer in accessing, critically assessing, and leveraging findings from literature papers to analyze a broader topic -- comparing TLR and LRR-RLK signalling -- helped me to build a skill set that will be invaluable to my future studies and career.