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

Abstract

SFH1 (for Snf5 homolog) protein, comprised in the RSC (Remodels Structure of Chromatin) 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 Sclerotinia sclerotiorum, 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 Sssfh1 (SS1G_01151) encodes a protein including a GATA-box domain and a SNF5 domain. Here, we characterized the roles of Sssfh1 in the developmental process and fungal pathogenicity by using RNA interference (RNAi)-based gene silencing in S. sclerotiorum. RNA-silenced strains with significantly reduced Sssfh1 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 S. sclerotiorum. Furthermore, Sssfh1-silenced strains exhibited enhanced tolerance to NaCl and H2O2. Results of infection assays on soybean and common bean (Phaseolus vulgaris) leaves indicated that Sssfh1 is required for full virulence of S. sclerotiorum during infection in the susceptible host plants. Collectively, our results suggest that the TF SsSFH1 is involved in growth, ROS accumulation and virulence in S. sclerotiorum.

Proteomics Analysis of SsNsd1-Mediated Compound Appressoria Formation in Sclerotinia sclerotiorum

“…The GATA-family transcription factors are involved in several essential aspects of the life cycle of M. oryzae , especially in the regulation of appressorium development and sporulation [ 41 ]. In S. sclerotiorum , the GATA-type transcription factors SsSFH1 and SsNsd1 were recently reported to be involved in the development of compound appressoria [ 4 , 42 ]. Here, phylogenetic analysis was performed, and transcription accumulation of all the predicted GATA-type proteins was detected.…”

“…From the genome of S. sclerotiorum , nine proteins are predicted to containing GATA-type DNA domains: SS1G_1036, SS1G_11953, SS1G_12238, SS1G_03252, SS1G_08523, SS1G_05040, SS1G_09784, SS1G_03775, and SS1G_01151 [ 4 , 42 ]. The BLASTX program at NCBI ( ) was employed to search for the homologs of the sequence of the SsNsd1 (SS1G_1036) and other GATA-type proteins from pathogenic fungi ( Botrytis cinerea , Fusarium oxysporum , Magnaporthe oryzae , and Aspergillus oryzae ).…”

The Notorious Soilborne Pathogenic Fungus Sclerotinia sclerotiorum: An Update on Genes Studied with Mutant Analysis

“…Sfh1 is a GATA transcription factor, but with an SNF5 domain. It is a member of the housekeeping RSC (Remodels Structure of Chromatin) complex, which is an ATP-dependent chromatin remodeler that is essential for cell cycle [34]. Its diverse functions explain its involvement in growth, sclerotial development, and virulence.…”

Distribution, evolution and expression ofGATA-TFsprovide new insights into their functions in light response and fruiting body development ofTolypocladium guangdongense

“…Urbs-1 in the basidiomycete Ustilago maydis and SREA in the Ascomycete A. nidulans , are both ‘vertebrate-like’ GATA-TFs that act as inhibitors, repressing siderophore biosynthesis ( An et al, 1997 ; Lee et al, 2013 ). In addition, a newly found GATA-TF Ssams2 in Sclerotinia sclerotiorum , which has a threonine residue in the seventh position of the Zn finger loop, is involved in appressoria formation and chromosome segregation ( Liu et al, 2018a ; Liu et al, 2018b ). However, among the GATA-TFs mentioned above, the light-responsive WC-1 and WC-2, and the nitrogen regulators AreA and AreB, play global roles in fungal growth and development across different species ( Niehaus et al, 2017 ; Pfannmüller et al, 2017 ).…”

“…In lower eukaryotes such as S. cerevisiae , the family of GATA-TFs contains over 10 members, and the functions of some members are well known ( Lowry & Atchley, 2000 ; Ronsmans et al, 2019 ). In some plant pathogenic fungi, such as B. cinerea ( Schumacher et al, 2014 ), F. fujikuroi ( Niehaus et al, 2017 ), S. sclerotiorum ( Liu et al, 2018a ; Liu et al, 2018b ; Li et al, 2018 ), and Magnaporthe oryzae ( Quispe, 2011 ), several GATA-TFs have been successively identified. Several orthologous proteins have also been identified in A. nidulans ( Han et al, 2001 ; Lee et al, 2013 ; Lee et al, 2014 ).…”