• The Plant Pathology Journal
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• v.28 no.2
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• pp.156-163
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• 2012

Stem rots caused by Rhizoctonia solani and Sclerotinia sclerotiorum have been known as devastating diseases in balloon flower plants. Antifungal activities of four fungicides, azoxystrobin, polyoxin B, trifloxystrobin and validamycin A were evaluated in vitro, showing effective suppression with mycelial growth of the fungal isolates on PDA media. Efficacies of the four fungicides were also demonstrated in stem tissues of balloon flower plants against R. solani and S. sclerotiorum. A commercially available Bacillus subtilis strain Y1336 was tested in terms of antagonistic biological control of stem rot disease of balloon flower plants. The bacterial strain revealed its antifungal activities against R. solani and S. sclerotiorum demonstrated by dual culture tests using paper discs and two plant pathogenic fungi on PDA media, as well as by plant inoculation assay, indicating that this antagonistic bacterial strain can be incorporated into disease management program for balloon flower stem rot diseases together with the four chemical fungicides.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1306-1318
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• 2009

The filamentous ascomycete Sclerotinia sclerotiorum is well known for its ability to produce a large variety of hydrolytic enzymes. Two $\alpha$-amylases ScAmy54 and ScAmy43 predicted to play an important role in starch degradation were showed to produce specific oligosaccharides essentially maltotriose that have a considerable commercial interest. Primary structure of the two enzymes was established by N-terminal sequencing, MALDI-TOF masse spectrometry and cDNA cloning. The two proteins have the same N-terminal catalytic domain and ScAmy43 derived from ScAmy54 by truncation of 96 amino acids at the carboxyl-terminal region. Data of genomic analysis suggested that the two enzymes originated from the same $\alpha$-amylase gene and that truncation of ScAmy54 to ScAmy43 occurred probably during S. sclerotiorum cultivation. The structural gene of Scamy54 consisted of 9 exons and 8 introns, containing a single 1,500-bp open reading frame encoding 499 amino acids including a signal peptide of 21 residues. ScAmy54 exhibited high amino acid homology with other liquefying fungal $\alpha$-amylases essentially in the four conserved regions and in the putative catalytic triad. A 3D structure model of ScAmy54 and ScAmy43 was built using the 3-D structure of 2guy from A. niger as template. ScAmy54 is composed by three domains A, B, and C, including the well-known $(\beta/\alpha)_8$ barrel motif in domain A, have a typical structure of $\alpha$-amylase family, whereas ScAmy43 contained only tow domains A and B is the first fungal $\alpha$-amylase described until now with the smallest catalytic domain.

• The Korean Journal of Mycology
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• v.27 no.3 s.90
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• pp.198-205
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• 1999

Cucurbitaceous vegetable crops grown in greenhouses in Korea were surveyed from 1995 to 1997. Incidence of Sclerotinia rot was as high as $30{\sim}70%$ at its maximum on Cucumis melo var. reticulatus (netted melon), Cucumis sativus (cucumber), Cucurbita moschata (pumpkin) and Cucurbita pepo (summer squash) but relatively low on Citrullus lanatus (watermelon) and Cucumis melo var. makuwa (oriental melon). Symptoms of Sclerotinia rot developed on stems of all the cucurbits, fruits of five cucurbits except C. lanatus, petioles of two Cucurbita spp. and leaves of C. moschata. A total of 126 isolates of Sclerotinia sp. were obtained from the lesions and identified as Sclerotinia sclerotiorum based on the morphological and cultural characteristics. The fungus was very frequently isolated from stems and fruits of the cucurbits but rarely from petioles and leaves. Six isolates of the fungus were pathogenic to six cucurbits tested although there was some difference in virulence among the isolates to some of the hosts. C. lanatus was the most susceptible to the isolates, whereas C. melo var. makuwa was the most resistant. C. melo var. reticulatus and C. sativus were relatively susceptible to the isolates, and C. moschata and C. pepo relatively resistant.

• Mycobiology
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• v.50 no.5
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• pp.382-388
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• 2022

White mold (or Sclerotinia stem rot), caused by Sclerotinia species, is a major air, soil, or seed-transmitted disease affecting numerous crops and wild plants. Microscopic or culture-based methods currently available for their detection and identification are time-consuming, laborious, and often erroneous. Therefore, we developed a multiplex quantitative PCR (qPCR) assay for the discrimination, detection, and quantification of DNA collected from each of the three economically relevant Sclerotinia species, namely, S. sclerotiorum, S. minor, and S. nivalis. TaqMan primer/probe combinations specific for each Sclerotinia species were designed based on the gene sequences encoding aspartyl protease. High specificity and sensitivity of each probe were confirmed for sclerotium and soil samples, as well as pure cultures, using simplex and multiplex qPCRs. This multiplex assay could be helpful in detecting and quantifying specific species of Sclerotinia, and therefore, may be valuable for disease diagnosis, forecasting, and management.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.598-605
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• 2017

To isolate rhizobacteria exhibiting antifungal activities for for five pathogenic fungi (Sclerotinia sclerotiorum, Fusarium solani, Collectotricum gloeosporides, Fusarium oxysporum, and Botrytis cinerea) which cause damage to Ginseng root in Ginseng grown fields, four soils were collected from Cheorlwon gun, in Korea. From 4 soils, a total of 160 bacterial strains were isolated by dilution plate method. Among 160 strains, 32 strains showed antifungal activities for one or more pathogens. From 32 strains, three strains exhibited antifungal activities for all pathogens. These are two Burkholderia cepacia (ATCC 25416 and ET 13) and one Paenibacillus polymyxa (ATCC 842). These potent antifungal strains showed high identities (99% using 16S-rRNA sequencing).

• The Plant Pathology Journal
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• v.22 no.2
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• pp.107-114
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• 2006

The white cottony stem rot pathogen Sclerotinia scierotiorum was subjected to 70 different isolates of actinomycetes indigenous to Jordan as biological control agents. Forty of them demonstrated chitinase activity on crab shell chitin agay (CCA) media and they were segregated into three groups: 14 highly active, 12 moderately active, and 14 with low activity, with average clearing zones of (4.7-8.3), (3.7-4.3), and (2.3-3.3) mm surrounding colonies on CCA, respectively. Further, these isolates were able to inhibit radial mycelium growth of the pathogen and were categorized into three antagonistic groups: 13 strong, 13 moderate, and 14 weak antagonists, with antibiosis inhibition Bones of (32.0-45.7), (22.7-31.3), and (3.7-22.3) mm, respectively. High levels of chitinase activity of the isolates Ma3 (8.3 mm), Jul (7.7 mm), and Sa8 (7.7 mm) with their antagonistic activity against mycelium growth of 45.7, 44.3, and 40.7 mm were observed, respectively. These isolates exhibited fungicidal activity against sclevotia of S. sclerotiorum. On the other hand, isolates Na5, Aj3, and Aj2 that produced no chitinase showed fungistatic effect only.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.39-51
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• 2023

Common bean (Phaseolus vulgaris L.) is one of the most important crops in human food production. The occurrence of diseases, such as white mold, caused by Sclerotinia sclerotiorum can limit the production of this legume. The use of Trichoderma has become an important strategy in the suppression of this disease. The aim of the present study was to evaluate the effect of volatile organic compounds (VOCs) emitted by Trichoderma azevedoi CEN1241 in five different growth periods on the severity of white mold in common bean. The in vitro assays were carried out in double-plate and split-plate, and the in vivo assays, through the exposure of the mycelia of S. sclerotiorum to the VOCs of T. azevedoi CEN1241 and subsequent inoculation in bean plants. Chemical analysis by gas chromatography coupled to mass spectrometry detected 37 VOCs produced by T. azevedoi CEN1241, covering six major chemical classes. The profile of VOCs produced by T. azevedoi CEN1241 varied according to colony age and was shown to be related to the ability of the biocontrol agent to suppress S. sclerotiorum. T. azevedoi CEN1241 VOCs reduced the size of S. sclerotiorum lesions on bean fragments in vitro and reduced disease severity in a greenhouse. This study demonstrated in a more applied way that the mechanism of antibiosis through the production of volatile compounds exerted by Trichoderma can complement other mechanisms, such as parasitism and competition, thus contributing to a better efficiency in the control of white mold in bean plants.

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.743-751
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• 2019

Sclerotinia rot, caused by Sclerotinia sclerotiorum, is a devastating disease that poses a serious threat to perilla production in Korea. Identifying effective sources of resistance offers long term prospects for improving management of this disease. Screening disease resistant genetic resources is important for development of disease-resistant, new cultivars and conduct related research. In the present study, perilla germplasm were screened in vitro against S. sclerotiorum using detached leaf method. Among 544 perilla accessions, two were highly resistant (IT226504, IT226533), five were resistant (IT226561, IT226532, IT226526, IT226441, and IT226589), five were moderately resistant (IT226525, IT226640, IT226568, IT220624, and IT178655), 16 were moderately susceptible, 31 were susceptible, and 485 were highly susceptible. The resistant accessions in this study could serve as resistance donor in the breeding of Sclerotinia rot resistance or subjected to selection procedure of varietal development for direct use by breeders, farmers, researchers, and end consumers.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1555-1563
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• 2008

A novel $\alpha$-amylase ($\alpha$-1,4-$\alpha$-D-glucan glucanohydrolase, E.C. 3.2.1.1), ScAmy43, was found in the culture medium of the phytopathogenic fungus Sclerotinia sclerotiorum grown on oats flour. Purified to homogeneity, ScAmy43 appeared as a 43 kDa monomeric enzyme, as estimated by SDS-PAGE and Superdex 75 gel filtration. The MALDI peptide mass fingerprint of ScAmy43 tryptic digest as well as internal sequence analyses indicate that the enzyme has an original primary structure when compared with other fungal a-amylases. However, the sequence of the 12 N-terminal residues is homologous with those of Aspergillus awamori and Aspergillus kawachii amylases, suggesting that the new enzyme belongs to the same GH13 glycosyl hydrolase family. Assayed with soluble starch as substrate, this enzyme displayed optimal activity at pH 4 and $55^{\circ}C$ with an apparent $K_m$ value of 1.66 mg/ml and $V_{max}$ of 0.1${\mu}mol$glucose $min^{-1}$ $ml^{-1}$. ScAmy43 activity was strongly inhibited by $Cu^{2+}$, $Mn^{2+}$, and $Ba^{2+}$, moderately by $Fe^{2+}$, and was only weakly affected by $Ca^{2+}$ addition. However, since EDTA and EGTA did not inhibit ScAmy43 activity, this enzyme is probably not a metalloprotein. DTT and $\beta$-mercaptoethanol strongly increased the enzyme activity. Starting with soluble starch as substrate, the end products were mainly maltotriose, suggesting for this enzyme an endo action.

• Journal of Plant Biotechnology
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• v.38 no.3
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• pp.209-214
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• 2011

Transgenic lettuce plants were successfully obtained from hypocotyl explants inoculated with Agrobacterium tumefaciens, which harbored a binary vector plasmid with Bcl-2 gene, related to apoptosis. After culture and selection on MS medium a number of kanamycin-resistant plantlets were regenerated. Polymerase chain reaction, Southern blot analysis and Northern blot analysis were used to identify and characterize the transgenic plants with the integrated Bcl-2 gene. Over 100 transgenic plants have been established in soil and flowered in the greenhouse. T1 progeny of 100 transgenic lettuce inbred lines were inoculated with Sclerotinia sclerotiorum. Expression of the Bcl-2 peptide in transgenic lettuce plants provides high levels of field resistance against Sclerotinia sclerotiorum, causal agent of the agronomically important fungal disease of lettuce.