Samuel Osabutey

My research focuses on understanding the evolutionary and ecological mechanisms driving the emergence of bacterial plant pathogens, with particular emphasis on Pseudomonas syringae pv. aptata, the causal agent of bacterial leaf spot in table beet, Swiss chard, and several cucurbit crops. P. syringae pv. aptata is a genetically diverse pathogen within the P. syringae species complex, which includes both pathogenic and non-pathogenic strains that coexist on plant surfaces and in seeds. The emergence of novel, more virulent lineages poses significant challenges to vegetable and seed production worldwide.

I investigate how horizontal gene transfer contributes to the evolution of new pathogen lineages and whether these genetic exchange events are influenced by the host environment, particularly differences in cultivar resistance and susceptibility. My research examines the movement of mobile genetic elements, including effectors, pathogenicity islands, plasmids, copper resistance genes, and other virulence-associated genes, among P. syringae populations and between members of the plant-associated microbiome. In addition, I study how the phytobiome shapes pathogen evolution by characterizing microbial communities associated with leaves and identifying genetic reservoirs that may facilitate the acquisition of adaptive traits. I am particularly interested in determining whether non-pathogenic P. syringae strains can acquire virulence genes through horizontal gene transfer and evolve into pathogenic lineages with specificity toward particular host plants.

By integrating plant pathology, microbial ecology, comparative genomics, and microbiome science, my research seeks to uncover the mechanisms underlying pathogen emergence and adaptation. Ultimately, I aim to generate knowledge that supports the development of durable host resistance, improved disease surveillance, and sustainable management strategies to reduce the emergence and spread of bacterial plant diseases.

Publications 

• Hamidizade, M., Smith, A. C., Osabutey, S., Potnis, N., & Bull, C. T. (2026). A Genome-Anchored TaqMan^TM qPCR Assay for the Specific Detection of an Aggressive Genotype of Pseudomonas syringae pv. aptata. Plant Disease (10.1094/PDIS-03-26-0442-RE).
• Honger, J. O., Ofoe, R., Osabutey, S., & Abbey, A. A. (2024). Importance, etiology and management of the bacterial black spot disease of mango. Indian Phytopathology, 77(3), 681-691.

• Joseph O. H, Osabutey, Tatu S. N, John B. L. (2021). Molecular characterization, pathogenicity, and copper sensitivity of Xanthomonas citri pv. mangiferaeindicae, the causal agent of mango bacterial black spot disease in Ghana. (Archives of Phytopathology and Plant Protection).

• Honger, J. O., Ofoe, R., Osabutey, S., & Abbey, A. A. (2024). Importance, etiology, and management of the bacterial black spot disease of mango. Indian Phytopathology, 77(3), 681-691.
• T. Nyaku, H. Lutuf, J.O. Honger, A. Dede, F.C. Brentu, R. Benissan, S. Osabutey, V. Larbi, E. Koranteng, C. Afun, M. Okyere, and F. K. Ablormeti. Prevalence of plant-parasitic nematodes in rice fields in Ghana. 2022- (African Crop Science Journal).

• Abdullah, K. E., Nyaku, S. T., Osabutey S., Lutuf, H., and Cornelius, E. W. “Prevalence of yam nematode in soil communities and morphometrics in the Krachi-Nchumuru district of Ghana” 2023 (African Crop Science Journal)

• Agyapong, A. F., Ofoe, R., Darkwa, E., Eleblu, S. Y, Pangariyi, B., Osabutey, S.^: Eleblu, J. S. Y. (2023). Detection, Identification and Management of Seed-borne fungal Pathogens on Farmer-Saved Soybean (Glycine max (L.) Merrill) seeds in Ghana. Science and Development Journal, 7(2), 123-123.

Grants and Awards

• American Phytopathology Society-FoundationRaymon G. Grogan Student Travel Fund (June, 2025)
• James F. & Marilyn L. Tammen Memorial Endowment for International Plant Pathology (June, 2025)
• CAS Graduate Student Travel Awards by Sahakian Endowment (April, 2025)
• University Park Allocation Committee (UPAC) travel award (June, 2025)
• G. Leventis Scholarship Award for Graduate Studies, University of Ghana (2018/2019 Academic year).