title: Vayg1 is required for microsclerotium formation and melanin production in Verticillium dahliae.
abstract: The fungus Verticillium dahliae causes vascular wilt disease on many plant species, including economically important crop and ornamental plants worldwide. It produces darkly pigmented resting structures known as microsclerotia, which are able to survive for up to 14years in soil, and represent one of the defining characteristics of this species. The pigment produced in V. dahliae is dihydroxynaphthalene (DHN)-melanin, a form of melanin common among fungi and named so for the intermediary of this melanin biosynthetic pathway. In this study, we characterized the function of the V. dahliae Vayg1 gene, whose homologs were involved in melanin biosynthesis in Exophiala dermatitidis (Wayg1) and Aspergillus fumigatus (Aayg1), by deletion and complementation of the gene and co-incubating deletion mutant with wild-type strain. Results showed that melanin production and microsclerotial formation in deletion mutants are inhibited. The Vayg1 deletion mutant also exhibited reduced pathogenicity. These results showed that Vayg1 is necessary for melanin and microsclerotium production, and we may thus hypothesize that the Vayg1 product may catalyze two different precursors, one of which is essential for DHN melanin production and the other one is involved in a signal network for microsclerotial formation in V. dahliae.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Department of Plant Pathology, College of Plant Protection, Northwest A&F University, Yangling 712100, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Fan
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, 1636 E. Alisal Street, Salinas, CA 93905, United States.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Klosterman
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Department of Plant Pathology, College of Plant Protection, Northwest A&F University, Yangling 712100, China.
authors.forename: Conghao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Plant Pathology, University of California, Davis, c/o U.S. Agricultural Research Station, 1636 E. Alisal Street, Salinas 93905, United States.
authors.forename: Krishna V
authors.initials: KV
authors.lastname: Subbarao
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Department of Plant Pathology, College of Plant Protection, Northwest A&F University, Yangling 712100, China; NIAB East Malling Research (EMR), West Malling ME19 6BJ, UK.
authors.forename: Xiangming
authors.initials: X
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Department of Plant Pathology, College of Plant Protection, Northwest A&F University, Yangling 712100, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Shang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Department of Plant Pathology, College of Plant Protection, Northwest A&F University, Yangling 712100, China. Electronic address: xphu@nwsuaf.edu.cn.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Hu
mesh_terms: D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D008543:Melanins / Q000096:biosynthesis / Q000235:genetics*; D009284:Naphthols; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D017384:Sequence Deletion; D013172:Spores, Fungal / Q000235:genetics* / Q000472:pathogenicity; D020172:Verticillium / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity
chemical_list: C423455:1,8-dihydroxynaphthalene melanin; D005656:Fungal Proteins; D008543:Melanins; D009284:Naphthols
keywords: Gene expression regulator; Melanin; Microsclerotia; Pathogenicity