title: An atypical forkhead-containing transcription factor SsFKH1 is involved in sclerotial formation and is essential for pathogenicity in Sclerotinia sclerotiorum.
abstract: Sclerotinia sclerotiorum (Lib.) de Bary is a necrotrophic plant pathogen with a worldwide distribution. The sclerotia of S. sclerotiorum are pigmented multicellular structures formed from the aggregation of vegetative hyphae. These survival structures play a central role in the life and infection cycles of this pathogen. Here, we characterized an atypical forkhead (FKH)-box-containing protein, SsFKH1, involved in sclerotial development and virulence. To investigate the role of SsFkh1 in S. sclerotiorum, the partial sequence of SsFkh1 was cloned and RNA interference (RNAi)-based gene silencing was employed to alter the expression of SsFkh1. RNA-silenced mutants with significantly reduced SsFkh1 RNA levels exhibited slow hyphal growth and sclerotial developmental defects. In addition, the expression levels of a set of putative melanin biosynthesis-related laccase genes and a polyketide synthase-encoding gene were significantly down-regulated in silenced strains. Disease assays demonstrated that pathogenicity in RNAi-silenced strains was significantly compromised with the development of a smaller infection lesion on tomato leaves. Collectively, the results suggest that SsFkh1 is involved in hyphal growth, virulence and sclerotial formation in S. sclerotiorum.
authors.affiliation: College of Plant Sciences, Jilin University, Changchun, 130062, China.
authors.forename: Huidong
authors.initials: H
authors.lastname: Fan
authors.affiliation: College of Plant Sciences, Jilin University, Changchun, 130062, China.
authors.forename: Gang
authors.identifier: 0000-0002-6720-7490
authors.initials: G
authors.lastname: Yu
authors.affiliation: College of Plant Sciences, Jilin University, Changchun, 130062, China.
authors.forename: Yanzhi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Plant Sciences, Jilin University, Changchun, 130062, China.
authors.forename: Xianghui
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Plant Sciences, Jilin University, Changchun, 130062, China.
authors.forename: Jinliang
authors.initials: J
authors.lastname: Liu
authors.affiliation: College of Plant Sciences, Jilin University, Changchun, 130062, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Plant Pathology, University of Florida, Gainesville, FL, 32611, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Rollins
authors.affiliation: School of Science and Technology, Georgia Gwinnett College, Lawrenceville, GA, 30024, USA.
authors.forename: Fengjie
authors.initials: F
authors.lastname: Sun
authors.affiliation: College of Plant Sciences, Jilin University, Changchun, 130062, China.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Pan
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000235:genetics / Q000472:pathogenicity*; D051858:Forkhead Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D055785:Gene Knockdown Techniques; D025301:Hyphae / Q000166:cytology / Q000254:growth & development; D008543:Melanins / Q000096:biosynthesis; D009154:Mutation / Q000235:genetics; D009997:Osmotic Pressure; D018384:Oxidative Stress; D034622:RNA Interference; D014774:Virulence / Q000235:genetics
chemical_list: D051858:Forkhead Transcription Factors; D005656:Fungal Proteins; D008543:Melanins
keywords: RNA interference; Sclerotinia sclerotiorum; SsFkh1; pathogenicity; sclerotial formation