Polyamine metabolism during sclerotial development of Sclerotinia sclerotiorum

A nonsclerotial mutant of Sclerotinia sclerotiorum was produced by mutagenesis with 8-methoxypsoralen and ultraviolet light. The mutant, SL-1, failed to produce sclerotia on artificial media, infested grain, or on infected plants. The mutant remained pathogenic to eight plant species susceptible to the wild-type parental strain of the fungus. The mutant, SL-1, is potentially useful for physiological studies on sclerotial development and for investigation of its potential for biological weed control.Key words: Sclerotinia, mutant, sclerotialess, biocontrol, weeds.

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The putrescine analogue 1-aminooxy-3-aminopropane perturbs polyamine metabolism in the phytopathogenic fungus Sclerotinia sclerotiorum

Archives of Microbiology ◽

10.1007/s00203-003-0572-1 ◽

2003 ◽

Vol 180 (3) ◽

pp. 169-175 ◽

Cited By ~ 12

Author(s):

Oscar A. Ruiz ◽

Andr�s G�rriz ◽

Mar�a C. Dalmasso ◽

Fernando L. Pieckenstain

Keyword(s):

Sclerotinia Sclerotiorum ◽

Polyamine Metabolism ◽

Phytopathogenic Fungus

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Sclerotinia sclerotiorum Thioredoxin Reductase Is Required for Oxidative Stress Tolerance, Virulence, and Sclerotial Development

Frontiers in Microbiology ◽

10.3389/fmicb.2019.00233 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 2

Author(s):

Jinyi Zhang ◽

Yabo Wang ◽

Jiao Du ◽

Zhiqiang Huang ◽

Anfei Fang ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Tolerance ◽

Sclerotinia Sclerotiorum ◽

Thioredoxin Reductase ◽

Oxidative Stress Tolerance ◽

Sclerotial Development

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The Sclerotinia sclerotiorum pac1 Gene Is Required for Sclerotial Development and Virulence

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2003.16.9.785 ◽

2003 ◽

Vol 16 (9) ◽

pp. 785-795 ◽

Cited By ~ 181

Author(s):

Jeffrey A. Rollins

Keyword(s):

Oxalic Acid ◽

Sclerotinia Sclerotiorum ◽

Acid Production ◽

Plant Pathogens ◽

Gene Replacement ◽

Loss Of Function ◽

Physiological Processes ◽

Gene Transcripts ◽

Sclerotial Development

The synergistic activities of oxalic acid and endopolygalacturonases are thought to be essential for full virulence of Sclerotinia sclerotiorum and other oxalate-producing plant pathogens. Both oxalic acid production and endopolygalacturonase activity are regulated by ambient pH. Since many gene products with pH-sensitive activities are regulated by the PacC transcription factor in Aspergillus nidulans, we functionally characterized a pacC gene homolog, pac1, from S. sclerotiorum. Mutants with loss-of-function alleles of the pac1 locus were created by targeted gene replacement. In vitro mycelial growth of these pac1 mutants was normal at acidic pH, but growth was inhibited as culture medium pH was increased. Development and maturation of sclerotia in culture was also aberrant in these pac1 replacement mutants. Although oxalic acid production remained alkaline pH-responsive, the kinetics and magnitude of oxalate accumulation were dramatically altered. Additionally, maximal accumulation of endopolygalacturonase gene transcripts (pg1) was shifted to higher ambient pH. Virulence in loss-of-function pac1 mutants was dramatically reduced in infection assays with tomato and Arabidopsis. Based on these results, pac1 appears to be necessary for the appropriate regulation of physiological processes important for pathogenesis and development of S. sclerotiorum.

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Characterization of microRNA-like RNAs associated with sclerotial development in Sclerotinia sclerotiorum

Fungal Genetics and Biology ◽

10.1016/j.fgb.2020.103471 ◽

2020 ◽

Vol 144 ◽

pp. 103471

Author(s):

Zihao Xia ◽

Zehao Wang ◽

Nat N.V. Kav ◽

Chengsong Ding ◽

Yue Liang

Keyword(s):

Sclerotinia Sclerotiorum ◽

Sclerotial Development

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MAPK Regulation of Sclerotial Development in Sclerotinia sclerotiorum Is Linked with pH and cAMP Sensing

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2004.17.4.404 ◽

2004 ◽

Vol 17 (4) ◽

pp. 404-413 ◽

Cited By ~ 76

Author(s):

Changbin Chen ◽

Arye Harel ◽

Rena Gorovoits ◽

Oded Yarden ◽

Martin B. Dickman

Keyword(s):

Signaling Pathway ◽

Sclerotinia Sclerotiorum ◽

Specific Inhibitor ◽

Broad Host Range ◽

Environmental Signals ◽

Mitogen Activated Protein ◽

Fungal Phytopathogen ◽

Ph Conditions ◽

Sclerotial Development ◽

Dependent Signaling Pathway

Sclerotial development is fundamental to the disease cycle of the omnivorous broad host range fungal phytopathogen Sclerotinia sclerotiorum. We have isolated a highly conserved homolog of ERK-type mitogen-activated protein kinases (MAPKs) from S. sclerotiorum (Smk1) and have demonstrated that Smk1 is required for sclerotial development. The smk1 transcription and MAPK enzyme activity are induced dramatically during sclerotiogenesis, especially during the production of sclerotial initials. When PD98059 (a specific inhibitor of the activation of MAPK by MAPK kinase) was applied to differentiating cultures or when antisense expression of smk1 was induced, sclerotial maturation was impaired. The smk1 transcript levels were highest under acidic pH conditions, suggesting that Smk1 regulates sclerotial development via a pH-dependent signaling pathway, involving the accumulation of oxalic acid, a previously identified pathogenicity factor that functions at least in part by reducing pH. Addition of cyclic AMP (cAMP) inhibited smk1 transcription, MAPK activation, and sclerotial development. Thus, S. sclerotiorum can coordinate environmental signals (such as pH) to trigger a signaling pathway mediated by Smk1 to induce sclerotia formation, and this pathway is negatively regulated by cAMP.

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Proteomic Analysis Reveals the Importance of Exudates on Sclerotial Development in Sclerotinia sclerotiorum

Journal of Agricultural and Food Chemistry ◽

10.1021/acs.jafc.0c06685 ◽

2021 ◽

Vol 69 (4) ◽

pp. 1430-1440

Author(s):

Jiamei Tian ◽

Caixia Chen ◽

Huiying Sun ◽

Zehao Wang ◽

Siegrid Steinkellner ◽

...

Keyword(s):

Sclerotinia Sclerotiorum ◽

Proteomic Analysis ◽

Sclerotial Development

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Identification and Characterization of Sclerotinia sclerotiorum NADPH Oxidases

Applied and Environmental Microbiology ◽

10.1128/aem.05472-11 ◽

2011 ◽

Vol 77 (21) ◽

pp. 7721-7729 ◽

Cited By ~ 73

Author(s):

Hyo-jin Kim ◽

Changbin Chen ◽

Mehdi Kabbage ◽

Martin B. Dickman

Keyword(s):

Sclerotinia Sclerotiorum ◽

Fungal Pathogen ◽

Ros Generation ◽

Broad Host Range ◽

Nadph Oxidases ◽

Content Type ◽

Beneficial Effects ◽

Sclerotial Development ◽

Identification And Characterization

ABSTRACTNumerous studies have shown both the detrimental and beneficial effects of reactive oxygen species (ROS) in animals, plants, and fungi. These organisms utilize controlled generation of ROS for signaling, pathogenicity, and development. Here, we show that ROS are essential for the pathogenic development ofSclerotinia sclerotiorum, an economically important fungal pathogen with a broad host range. Based on the organism's completed genome sequence, we identified twoS. sclerotiorumNADPH oxidases (SsNox1 and SsNox2), which presumably are involved in ROS generation. RNA interference (RNAi) was used to examine the function of SsNox1 and SsNox2. Silencing of SsNox1 expression indicated a central role for this enzyme in both virulence and pathogenic (sclerotial) development, while inactivation of the SsNox2 gene resulted in limited sclerotial development, but the organism remained fully pathogenic. ΔSsnox1strains had reduced ROS levels, were unable to develop sclerotia, and unexpectedly correlated with significantly reduced oxalate production. These results are in accordance with previous observations indicating that fungal NADPH oxidases are required for pathogenic development and are consistent with the importance of ROS regulation in the successful pathogenesis ofS. sclerotiorum.

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Changes in Protein Kinase A Activity Accompany Sclerotial Development in Sclerotinia sclerotiorum

Phytopathology ◽

10.1094/phyto-95-0397 ◽

2005 ◽

Vol 95 (4) ◽

pp. 397-404 ◽

Cited By ~ 20

Author(s):

A. Harel ◽

R. Gorovits ◽

O. Yarden

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Sclerotinia Sclerotiorum ◽

Mitogen Activated Protein Kinase ◽

Intracellular Camp ◽

Activity Levels ◽

Developmental Phase ◽

Mapk Activity ◽

Sclerotial Development ◽

Kinase A

Sclerotia of Sclerotinia sclerotiorum are pigmented, multihyphal structures that play a central role in the life and infection cycles of this pathogen. Sclerotial formation has been shown to be affected by increased intracellular cAMP levels. Cyclic AMP (cAMP) is a key modulator of cAMP-dependent protein kinase A (PKA) and the latter may prove to play a significant role in sclerotial development. Therefore, we monitored changes in relative PKA activity levels during sclerotial development. To do so, we first developed conditions for near-synchronous sclerotial development in culture, based on hyphal maceration and filtering. Relative PKA activity levels increased during the white-sclerotium stage in the wild-type strain, while low levels were maintained in nonsclerotium-producing mutants. Furthermore, applying caffeine, an inducer of PKA activity, resulted in increased relative PKA activity levels and was correlated with the formation of sclerotial initial-like aggregates in cultures of the non-sclerotium-producing mutants. In addition, low PKA activities were found in an antisense smk1 strain, which exhibits low extracellular-signal-regulated kinase (ERK)-type mitogen-activated protein kinase (MAPK) activity, and does not produce sclerotia. The changes in PKA activity, as well as the abundance of phosphorylated MAPKs (ERK-like as well as p38-like) that accompany sclerotial development in a distinct developmental phase manner represent a potential target for antifungal intervention.

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