PPEM Seminar Series: James Standish (Ph.D. Student; Connecticut Ag Experiment Station & UConn)

Abstract: Fire blight, caused by Erwinia amylovora, is a destructive disease affecting Rosaceae crops such as apple and pear. Inducing plant defense through the application of chemical systemic acquired resistance (SAR) inducers or biological inducers is a well-established method for controlling fire blight. In addition to external inducers, different apple cultivars exhibit varying levels of susceptibility to the disease. However, it remains unclear whether fire blight-tolerant and susceptible apple cultivars respond equally to chemical and biological SAR inducers in terms of defense gene induction and disease control efficacy. In this study, we tested the SAR inducers acibenzolar-S-methyl (ASM; chemical) and Blossom Protect (BP; biological) for their ability to stimulate the SAR marker gene PR2 across three fire blight-tolerant and three fire blight-susceptible apple cultivars. Both ASM and BP induced PR2 expression in the fire blight-susceptible cultivars 2 and 4 days post treatment; however, such induction was not observed in the fire blight-tolerant cultivars. Despite their nonresponsiveness to the external inducers, the basal levels of SAR in tolerant cultivars did not differ from those in the susceptible cultivars. The PR2 induction by ASM and BP in all fire blight-susceptible cultivars ultimately led to a corresponding reduction in fire blight symptoms. In contrast, ASM and BP did not confer significant disease suppression on two of the three fire blight-tolerant cultivars, with the exception of ‘Liberty.’

Bio: James Standish is a Ph.D. student in Molecular and Cell Biology at the University of Connecticut. He earned his Bachelor’s degree in Biotechnology from Southern Connecticut State University. His research centers on fire blight, a devastating bacterial disease of apple and pear, where he applies genomics and transcriptomics to investigate interactions among the host, pathogen, and associated microbiome with the goal of developing effective disease prevention strategies. James joined Dr. Quan Zeng’s laboratory in the fall of 2022 working at the Connecticut Agricultural Experiment Station, where he was sponsored as a Ph.D. student at UConn and continues to work as graduate research assistant. In the fall of 2024 he also joined Dr. Victoria Robinson’s laboratory to facilitate a collaborative effort between the Connecticut Ag Station and the MCB department at UConn. Under their joint mentorship, he has advanced his research program and scholarly development. He has presented his work at major international conferences, including the International Conference on Plant Pathogenic Bacteria and Biocontrol and the International Fire Blight Symposium, as well as at regional and institutional meetings such as the Yale–Sussex Symposium on Plant Health and the Connecticut Agricultural Experiment Station Postdoctoral Symposium. He has also been invited to deliver seminars in the Molecular and Cell Biology Departmental Seminar Series at UConn and the Plant Pathology Seminar Series at Penn State. James is the first author of a publication accepted in The Plant Journal that identified and confirmed a novel pathway by which bacteria enter plants through wounds formed during the natural abscission of glandular and non-glandular trichomes.