scholarly journals An atypical forkhead-containing transcription factor SsFKH1 is involved in sclerotial formation and is essential for pathogenicity in Sclerotinia sclerotiorum

2016 ◽  
Vol 18 (7) ◽  
pp. 963-975 ◽  
Author(s):  
Huidong Fan ◽  
Gang Yu ◽  
Yanzhi Liu ◽  
Xianghui Zhang ◽  
Jinliang Liu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Sclerotinia Sclerotiorum ◽  
Sclerotial Formation

scholarly journals Transcriptional and Small RNA Responses of the White Mold Fungus Sclerotinia sclerotiorum to Infection by a Virulence-Attenuating Hypovirus

Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 713 ◽  
Author(s):  
Shin-Yi Lee Marzano ◽  
Achal Neupane ◽  
Leslie Domier
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Small Rna ◽  
Small Rnas ◽  
Large Scale ◽  
White Mold ◽  
Enhanced Production ◽  
Mold Fungus ◽  
Depth Analysis ◽  
Sclerotial Formation ◽  
In Trans

Mycoviruses belonging to the family Hypoviridae cause persistent infection of many different host fungi. We previously determined that the white mold fungus, Sclerotinia sclerotiorum, infected with Sclerotinia sclerotiorum hypovirus 2-L (SsHV2-L) exhibits reduced virulence, delayed/reduced sclerotial formation, and enhanced production of aerial mycelia. To gain better insight into the cellular basis for these changes, we characterized changes in mRNA and small RNA (sRNA) accumulation in S. sclerotiorum to infection by SsHV2-L. A total of 958 mRNAs and 835 sRNA-producing loci were altered after infection by SsHV2-L, among which >100 mRNAs were predicted to encode proteins involved in the metabolism and trafficking of carbohydrates and lipids. Both S. sclerotiorum endogenous and virus-derived sRNAs were predominantly 22 nt in length suggesting one dicer-like enzyme cleaves both. Novel classes of endogenous small RNAs were predicted, including phasiRNAs and tRNA-derived small RNAs. Moreover, S. sclerotiorum phasiRNAs, which were derived from noncoding RNAs and have the potential to regulate mRNA abundance in trans, showed differential accumulation due to virus infection. tRNA fragments did not accumulate differentially after hypovirus infection. Hence, in-depth analysis showed that infection of S. sclerotiorum by a hypovirulence-inducing hypovirus produced selective, large-scale reprogramming of mRNA and sRNA production.

scholarly journals The Formaldehyde Dehydrogenase SsFdh1 Is Regulated by and Functionally Cooperates with the GATA Transcription Factor SsNsd1 in Sclerotinia sclerotiorum

mSystems ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Genglin Zhu ◽  
Gang Yu ◽  
Xianghui Zhang ◽  
Jinliang Liu ◽  
Yanhua Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Zinc Finger ◽  
Sclerotinia Sclerotiorum ◽  
Promoter Region ◽  
Nuclear Translocation ◽  
Effective Control ◽  
Formaldehyde Dehydrogenase ◽  
Content Type ◽  
Gata Transcription Factor ◽  
Gata Box

ABSTRACT GATA transcription factors (TFs) are common eukaryotic regulators, and glutathione-dependent formaldehyde dehydrogenases (GD-FDH) are ubiquitous enzymes with formaldehyde detoxification activity. In this study, the formaldehyde dehydrogenase Sclerotinia sclerotiorum Fdh1 (SsFdh1) was first characterized as an interacting partner of a GATA TF, SsNsd1, in S. sclerotiorum. Genetic analysis reveals that SsFdh1 functions in formaldehyde detoxification, nitrogen metabolism, sclerotium development, and pathogenicity. Both SsNsd1 and SsFdh1 harbor typical zinc finger motifs with conserved cysteine residues. SsNsd1 regulates SsFdh1 in two distinct manners. SsNsd1 directly binds to GATA-box DNA in the promoter region of Ssfdh1; SsNsd1 associates with SsFdh1 through disulfide bonds formed by conserved Cys residues. The SsNsd1-SsFdh1 interaction and nuclear translocation were found to prevent efficient binding of SsNsd1 to GATA-box DNA. Site-directed point mutation of these Cys residues influences the SsNsd1-SsFdh1 interaction and SsNsd1 DNA binding capacity. SsFdh1 is regulated by and functions jointly with the SsNsd1 factor, providing new insights into the complex transcriptional regulatory mechanisms of GATA factors. IMPORTANCE S. sclerotiorum is a pathogenic fungus with sclerotium and infection cushion development, making S. sclerotiorum one of the most challenging agricultural pathogens with no effective control method. We identified important sclerotium and compound appressorium formation determinants, SsNsd1 and SsFdh1, and investigated their regulatory mechanism at the molecular level. SsNsd1 and SsFdh1 are zinc finger motif-containing proteins and associate with each other in the nucleus. On other hand, SsNsd1, as a GATA transcription factor, directly binds to GATA-box DNA in the promoter region of Ssfdh1. The SsNsd1-SsFdh1 interaction and nuclear translocation were found to prevent efficient binding of SsNsd1 to GATA-box DNA. Our results provide insights into the role of the GATA transcription factor and its regulation of formaldehyde dehydrogenase in stress resistance, fungal sclerotium and compound appressorium development, and pathogenicity.

scholarly journals pH Signaling in Sclerotinia sclerotiorum: Identification of a pacC/RIM1 Homolog

2001 ◽  
Vol 67 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Jeffrey A. Rollins ◽  
Martin B. Dickman
Keyword(s):  
Transcription Factor ◽  
Oxalic Acid ◽  
Signaling Pathway ◽  
Zinc Finger ◽  
Sclerotinia Sclerotiorum ◽  
Culture Conditions ◽  
Phytopathogenic Fungi ◽  
Molecular Signaling ◽  
Ph Conditions ◽  
Zinc Finger Domains

ABSTRACT Sclerotinia sclerotiorum acidifies its ambient environment by producing oxalic acid. This production of oxalic acid during plant infection has been implicated as a primary determinant of pathogenicity in this and other phytopathogenic fungi. We found that ambient pH conditions affect multiple processes in S. sclerotiorum. Exposure to increasing alkaline ambient pH increased the oxalic acid accumulation independent of carbon source, sclerotial development was favored by acidic ambient pH conditions but inhibited by neutral ambient pH, and transcripts encoding the endopolygalacturonase gene pg1 accumulated maximally under acidic culture conditions. We cloned a putative transcription factor-encoding gene, pac1, that may participate in a molecular signaling pathway for regulating gene expression in response to ambient pH. The three zinc finger domains of the predicted Pac1 protein are similar in sequence and organization to the zinc finger domains of the A. nidulans pH-responsive transcription factor PacC. The promoter of pac1 contains eight PacC consensus binding sites, suggesting that this gene, like its homologs, is autoregulated. Consistent with this suggestion, the accumulation ofpac1 transcripts paralleled increases in ambient pH. Pac1 was determined to be a functional homolog of PacC by complementation of an A. nidulans pacC-null strain with pac1. Our results suggest that ambient pH is a regulatory cue for processes linked to pathogenicity, development, and virulence and that these processes may be under the molecular regulation of a conserved pH-dependent signaling pathway analogous to that in the nonpathogenic fungus A. nidulans.

Sclerotinia sclerotiorum: An Evaluation of Virulence Theories

2018 ◽  
Vol 56 (1) ◽  
pp. 311-338 ◽  
Author(s):  
Liangsheng Xu ◽  
Guoqing Li ◽  
Daohong Jiang ◽  
Weidong Chen
Keyword(s):  
Oxalic Acid ◽  
Sclerotinia Sclerotiorum ◽  
Acid Production ◽  
Control Strategies ◽  
Critical Evaluation ◽  
Necessary Condition ◽  
Acidic Ph ◽  
Ph Sensing ◽  
Induced Mutants ◽  
Sclerotial Formation

Oxalic acid production in Sclerotinia sclerotiorum has long been associated with virulence. Research involving UV-induced, genetically undefined mutants that concomitantly lost oxalate accumulation, sclerotial formation, and pathogenicity supported the conclusion that oxalate is an essential pathogenicity determinant of S. sclerotiorum. However, recent investigations showed that genetically defined mutants that lost oxalic acid production but accumulated fumaric acid could cause disease on many plants and substantiated the conclusion that acidic pH, not oxalic acid per se, is the necessary condition for disease development. Critical evaluation of available evidence showed that the UV-induced mutants harbored previously unrecognized confounding genetic defects in saprophytic growth and pH responsiveness, warranting reevaluation of the conclusions about virulence based on the UV-induced mutants. Furthermore, analyses of the evidence suggested a hypothesis for the existence of an unrecognized regulator responsive to acidic pH. Identifying the unknown pH regulator would offer a new avenue for investigating pH sensing/regulation in S. sclerotiorum and novel targets for intervention in disease control strategies.

scholarly journals Random T-DNA Mutagenesis Identifies a Cu/Zn Superoxide Dismutase Gene as a Virulence Factor of Sclerotinia sclerotiorum

2013 ◽  
Vol 26 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Liangsheng Xu ◽  
Weidong Chen
Keyword(s):  
Oxidative Stress ◽  
Growth Rate ◽  
Superoxide Dismutase ◽  
Sclerotinia Sclerotiorum ◽  
Virulence Factor ◽  
Wild Type ◽  
Expression Levels ◽  
Sclerotial Formation ◽  
Increased Sensitivity ◽  
And Oxidative Stress

Agrobacterium-mediated transformation (AMT) was used to identify potential virulence factors in Sclerotinia sclerotiorum. Screening AMT transformants identified two mutants showing significantly reduced virulence. The mutants showed growth rate, sclerotial formation, and oxalate production similar to that of the wild type. The mutation was due to a single T-DNA insertion at 212 bp downstream of the Cu/Zn superoxide dismutase (SOD) gene (SsSOD1, SS1G_00699). Expression levels of SsSOD1 were significantly increased under oxidative stresses or during plant infection in the wild-type strain but could not be detected in the mutant. SsSOD1 functionally complemented the Cu/Zn SOD gene in a Δsod1 Saccharomyces cerevisiae mutant. The SOD mutant had increased sensitivity to heavy metal toxicity and oxidative stress in culture and reduced ability to detoxify superoxide in infected leaves. The mutant also had reduced expression levels of other known pathogenicity genes such as endo-polygalacturanases sspg1 and sspg3. The functions of SsSOD1 were further confirmed by SsSOD1-deletion mutation. Like the AMT insertion mutant, the SsSOD1-deletion mutant exhibited normal growth rate, sclerotial formation, oxalate production, increased sensitivity to metal and oxidative stress, and reduced virulence. These results suggest that SsSOD1, while not being required for saprophytic growth and completion of the life cycle, plays critical roles in detoxification of reactive oxygen species during host–pathogen interactions and is an important virulence factor of Sclerotinia sclerotiorum.

scholarly journals MADS-Box Transcription Factor SsMADS Is Involved in Regulating Growth and Virulence in Sclerotinia sclerotiorum

2014 ◽  
Vol 15 (5) ◽  
pp. 8049-8062 ◽  
Author(s):  
Xiaoyan Qu ◽  
Baodong Yu ◽  
Jinliang Liu ◽  
Xianghui Zhang ◽  
Guihua Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Sclerotinia Sclerotiorum ◽  
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