The Role of TuMV NIa-Pro in ACO4 Stability and Aphid Behavior in Nicotiana benthamiana

Plant viruses are major contributors to agricultural yield losses worldwide, in part due to their ability to manipulate host plant physiology and enhance transmission by insect vectors. Turnip mosaic virus (TuMV), a potyvirus infecting a wide range of crops, encodes the NIa-Pro protease, which has been shown to disrupt plant ethylene signaling and enhance aphid (Myzus persicae) performance. However, the molecular mechanisms behind this interaction are not well understood. Recent proteomic analyses in Nicotiana benthamiana identified ACC oxidase 4 (ACO4), a key enzyme in the ethylene biosynthesis, as a candidate interactor of NIa-Pro in the presence of aphids. It was hypothesized that NIa-Pro may regulate ACO4 protein turnover to influence ethylene dependent defenses, affecting aphid attraction and performance. Transient expression assay in N. benthamiana followed by western blotting demonstrated that ACO4 protein levels remained stable across increasing concentrations of NIa-Pro, suggesting that NIa-Pro does not alter ACO4 protein turnover. To test the biological significance of ACO4 overexpression in aphid behavior, aphid choice and fecundity assays were performed in ACO4 and NIa-Pro overexpressing N. benthamiana plants. Aphid behavioral assays revealed no significant differences in choice or fecundity among tested treatments. Future studies could explore the role of ACO4 during TuMV infection, as recent transcriptomic analyses show its expression is modulated in infected tissues. By contributing to the understanding of plant-virus-vector interactions, this research supports the efforts to develop crop protection and vector control strategies.

This internship was an important experience, both academically and personally. What was most exciting was to have the opportunity to learn and apply molecular biology techniques that I had only studied in theory, such as Agrobacterium-mediated infiltration, protein extraction, and Western blotting. I was not only able to practice these techniques, but also employ them together to answer a real research question. Throughout the summer I gained a deeper understanding of the entire research process, from reviewing knowledge gaps in literature, planning experiments and preparing reagents to analyzing data and drawing conclusions. By the end of the internship, I was able to conduct my experiments independently and confidently. I also learned to keep a detailed and organized lab notebook, documenting results and observations in a way that supported data analysis and reproducibility. Working with my mentor and lab team taught me how to troubleshoot protocols and make informed decisions when unexpected results were got. I became more familiar and comfortable using laboratory equipment and reagents, and I applied statistical analysis to interpret real experimental data and test hypotheses. This experience not only helped me develop practical research skills but also showed me what it means to think critically and scientifically. It reinforced my interest in molecular biology and clarified my desire to pursue graduate studies and a future career in scientific research.