AUTHOR=Liu Ling , Wang Qiaochu , Sun Ying , Zhang Yanhua , Zhang Xianghui , Liu Jinliang , Yu Gang , Pan Hongyu 

TITLE=Sssfh1, a Gene Encoding a Putative Component of the RSC Chromatin Remodeling Complex, Is Involved in Hyphal Growth, Reactive Oxygen Species Accumulation, and Pathogenicity in Sclerotinia sclerotiorum

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01828

DOI=10.3389/fmicb.2018.01828

ISSN=1664-302X

ABSTRACT=<p>SFH1 (for <underline>S</underline>n<underline>f</underline>5 <underline>h</underline>omolog) protein, comprised in the RSC (<underline>R</underline>emodels <underline>S</underline>tructure of <underline>C</underline>hromatin) chromatin remodeling complex, functions as a transcription factor (TF) to specifically regulate gene transcription and chromatin remodeling. As one of the well-conserved TFs in eukaryotic organisms, little is known about the roles of SFH1 protein in the filamentous fungi. In <italic>Sclerotinia sclerotiorum</italic>, one of the notorious plant fungal pathogens, there are nine proteins predicted to contain GATA-box domain according to GATA family TF classification, among which <italic>Sssfh1</italic> (SS1G_01151) encodes a protein including a GATA-box domain and a SNF5 domain. Here, we characterized the roles of <italic>Sssfh1</italic> in the developmental process and fungal pathogenicity by using RNA interference (RNAi)-based gene silencing in <italic>S. sclerotiorum</italic>. RNA-silenced strains with significantly reduced <italic>Sssfh1</italic> RNA levels exhibited slower hyphal growth and decreased reactive oxygen species (ROS) accumulation in hyphae compared to the wild-type (WT) strain. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays demonstrated that SsSFH1 interacts with SsMSG5, a MAPK phosphatase in <italic>S. sclerotiorum</italic>. Furthermore, <italic>Sssfh1</italic>-silenced strains exhibited enhanced tolerance to NaCl and H<sub>2</sub>O<sub>2</sub>. Results of infection assays on soybean and common bean (<italic>Phaseolus vulgaris</italic>) leaves indicated that <italic>Sssfh1</italic> is required for full virulence of <italic>S. sclerotiorum</italic> during infection in the susceptible host plants. Collectively, our results suggest that the TF SsSFH1 is involved in growth, ROS accumulation and virulence in <italic>S. sclerotiorum</italic>.</p>