title: Anastomosis is required for virulence of the fungal necrotroph Alternaria brassicicola.
abstract: A fungal mycelium is typically composed of radially extending hyphal filaments interconnected by bridges created through anastomoses. These bridges facilitate the dissemination of nutrients, water, and signaling molecules throughout the colony. In this study, we used targeted gene deletion and nitrate utilization mutants of the cruciferous pathogen Alternaria brassicicola and two closely related species to investigate hyphal fusion (anastomosis) and its role in the ability of fungi to cause disease. All eight of the A. brassicicola isolates tested, as well as A. mimicula and A. japonica, were capable of self-fusion, with two isolates of A. brassicicola being capable of non-self-fusion. Disruption of the anastomosis gene homolog (Aso1) in A. brassicicola resulted in both the loss of self-anastomosis and pathogenicity on cabbage. This finding, combined with our discovery that a previously described nonpathogenic A. brassicicola mutant defective for a mitogen-activated protein kinase gene (amk1) also lacked the capacity for self-anastomosis, suggests that self-anastomosis is associated with pathogenicity in A. brassicicola.
authors.affiliation: Department of Plant Pathology, North Carolina State University, Raleigh, USA.
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Craven
authors.forename: Heriberto
authors.initials: H
authors.lastname: Vélëz
authors.forename: Yangrae
authors.initials: Y
authors.lastname: Cho
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Lawrence
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Mitchell
mesh_terms: D000528:Alternaria / Q000166:cytology* / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D001483:Base Sequence; D001937:Brassica / Q000382:microbiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005816:Genetic Complementation Test; D025301:Hyphae / Q000378:metabolism; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D014774:Virulence
chemical_list: D005656:Fungal Proteins