Title Multiple roles of a putative vacuolar protein sorting associated protein 74, FgVPS74, in the cereal pathogen Fusarium graminearum
Author Hee-Kyoung Kim1, Ki Woo Kim2, and Sung-Hwan Yun1*
Address 1Department of Medical Biotechnology, Soonchunhyang University, Asan 336-745, Republic of Korea, 2School of Ecology & Environmental System, Kyungpook National University, Sangju 742-711, Republic of Korea
Bibliography Journal of Microbiology, 53(4),243-249, 2015,
DOI 10.1007/s12275-015-5067-7
Key Words vacuolar protein sorting-associated protein 74, Fusarium graminearum, hyphal growth, virulence, conidiation
Abstract Fusarium graminearum, a member of the F. graminearum species complex, is a filamentous ascomycetous group that causes serious diseases in cereal crops. A screen of insertional mutants of F. graminearum, generated using a restriction enzyme-mediated integration method, identified a mutant designated R7048 showing pleiotropic phenotypes in several mycological traits. The vector insertion site in the R7048 genome was identified as the KpnI site within an ORF annotated as FGSG_06346 (designated FgVPS74), which showed similarity to vacuolar protein sorting-associated protein 74 in the baker yeast. Both targeted gene deletion and complementation analyses confirmed that FgVPS74 was involved in hyphal growth, conidiation, sexual development, mycotoxin production, and virulence towards host plants in F. graminearum. Electron microscopy analysis revealed no significant changes in morphology of the vacuole or other organelles, but a greater number of mitochondria were produced in the ΔFgVPS74 strain compared to the wild-type progenitor. Expression of a GFP-tagged FgVPS74 construct under its native promoter in the ΔFgVPS74 strain exhibited localization of GFP signal to putative vesicle structures, but not to the vacuolar membrane. Taken together, these findings demonstrated that a functional vacuolar protein-sorting pathway mediated by FgVPS74 is crucial for fungal growth and development in F. graminearum.