• Korean Journal Plant Pathology
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• v.14 no.4
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• pp.319-324
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• 1998

Induction of systemic acquired resistance (SAR) against phytophthora blight and pathogenesis-related (PR) protein accumulation by TMV infection in pepper plant (Capsicum annuum cv. Nockwang) were examined to understand the mechanism of the systemic acquired resistance in pepper plant. The zoospore suspension of Phytophthora capsici was inoculated on stem of pepper plant in which TMV-pepper strain had been inoculated on fully expanded upper leaves, and thephytopha blight incidence was examined. Both disease severity and lesion length of phytophthora blight were much smaller in TMV pre-inoculated pepper plant than in uninoculated control plants. The phytophthora blight incidence was decreased about 50% in the TMV pre-inoculated pepper, compared to the uninoculated control plant at 10 days after P. capsici inoculation. Accumulation of PR1 and PR5 proteins in intercellular fluid of TMV-inoculated and uninoculated upper leaves were monitored by immuno-blot with tobacco P1b and PR5a, antibody during induction of SAR. PR1 and PR5 were detected from 24 hours after TMV inoculation in both TMV-inoculated and uninouclated upper leaves, and increased rapidly in TMV-inoculation in uninoculated upper leaves were defoliated. PR5 could be detected upto 20 days after TMV inoculation in uninoculated upper leaves. These results suggest that TMV infection induces SAR against phytophthora blight in pepper plant, and that PR proteins are accumulated very rapidly during induction of SAR and maintained for quite long time in pepper plant.

• The Plant Pathology Journal
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• v.15 no.6
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• pp.319-322
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• 1999

In order to obtain bacterial metabolites inducing disease resistance in pepper plant, two hundred bacterial isolates were isolated from the rhizosphere soil of tobacco, cucumber, and pepper plant. Ethyl acetate extract of each bacterial culture was used to screening for induction of resistance against phytophthora blight of pepper plant. Application of ethyl acetate extract of an isolate SH122 culture to pepper plant conferred resistance against phytophthora blight consistently and significantly. According to cellular fatty acid analysis and other characteristics, the SH122 culture were significantly lower than those on control plants treated with ethyl acetate extract of nutrient broth. The B. pumilus SH122 itself of ethyl acetate extract of its culture did not show antifungal activity against phytophthora blight in pepper plants.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.48-52
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• 1999

Ethaboxam is the first proprietary fungicide developed in Korea, registered in 1998 and commercialized in 1999 by LG Chemical Ltd., Korea. It is a derivative of aminothiazole carboxamide and formulated into 25% wettable powder for practical application in fields. Ethaboxam effectively controlled cucumber downy mildew caused by Pseudoperonospora cubensis, potato late blight caused by Phytophthora infestans, and pepper Phytophthora blight caused by P. capsici, and was superior or comparable to the commercial standards, when foliarly sprayed 3∼5 times until dripping off at approximately 7-day intervals during the growing season. Ethaboxam was required at least 125 mg/liter and 250 mg/liter for effective control of cucumber downy mildew, and potato late blight and pepper Phytophthora blight, respectively. There was not phytotoxicity observed o leaves, stems or fruits of cucumber, potato and pepper from any trial.

• Research in Plant Disease
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• v.30 no.2
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• pp.181-188
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• 2024

Southern blight, caused by the soil-borne fungus Sclerotium rolfsii, is a serious disease that affects many economically important crops. In this study, we selected Bacillus subtilis GJ6-14, from a total of 260 strains, to control Southern blight in pepper plants. In both seedling and plant tests, GJ6-14 significantly suppressed disease incidence and severity compared to control, furthermore, GJ6-14 demonstrated efficient colonization in the rhizosphere by maintaining the population from log 5.41 to log 3.92 in the pathogen-inoculated plants, indicating its potential as a biocontrol agent. Molecular analysis revealed up-regulation of defense-related genes, such as a 7.6-fold increase in LOX1 and 15.5-fold increase in PR1, at 72 hr after inoculation of S. rolfsii in GJ6-14-treated plants, suggesting activation of plant defense mechanisms. Overall, our findings highlight the promising role of B. subtilis GJ6-14 as a potential biocontrol agent in sustainable management of Southern blight in pepper plants.

• Research in Plant Disease
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• v.19 no.3
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• pp.208-215
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• 2013

3-(4-Hydroxyphenyl)-propionic acid (HPP) is a bacterial metabolite synthesized and released by an entomopathogenic bacterium Xenorhabdus nematophila K1. In this study, the control efficacy of HPP was tested against Phytophthora blight and anthracnose of red pepper plants. HPP suppressed mycelial growth of Phytophthora blight and anthracnose pathogens. Under natural sunlight condition, HPP maintained the antifungal activity on the diseases for at least twenty five days. The antifungal activity was not decreased even in the condition of soil-water. It was proved that HPP was able to penetrate the roots and travel upward of the red pepper plants. When HPP suspension was applied to soil rhizosphere before transplanting the red pepper seedlings or was regularly sprayed to the foliage of the plants with ten days interval, it resulted in significant reduction of the disease occurrences (Phytophthora blight and anthracnose) without any phytotoxicity. These results suggested that HPP can be developed to a systemic agrochemical against Phytophthora blight and anthracnose of red pepper plants.

• The Plant Pathology Journal
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• v.18 no.4
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• pp.221-224
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• 2002

In vitro and in vivo activities of a biocontrol agent, Serratia plymuthica strain A2l-4, was evaluated for the control of Phytophthora blight of pepper, Strain A2l-4 inhibited mycelial growth, germination of zoosporangia and cystospores, and formation of zoospore and zoosporangia of Phytophthora capsici in vitro. In the pot experiment, incidence of Phytophthora blight of pepper in non-treated control was 100% at 14 days after inoculation, while no disease was observed in the plot treated with S. plymuthica A2l-4. In the greenhouse test, infection rate of pepper in the non-treated plots was 74.5%, while it was only 12.6％ in the plots treated with A2l-4. Results indicate that S. plymuthica A2l-4 is a potential biocontrol agent for Phytophthora blight of pepper.

• The Plant Pathology Journal
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• v.33 no.3
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• pp.264-275
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• 2017

The spent mushroom substrate (SMS) of Lentinula edodes that was derived from sawdust bag cultivation was used as materials for controlling Phytophthora blight disease of pepper. Water extract from SMS (WESMS) of L. edodes inhibited mycelial growth of Phytophthora capsici, suppressed Phytophthora blight disease of pepper seedlings by 65% and promoted growth of the plant over 30%. In high performance liquid chromatography (HPLC) analysis, oxalic acid was detected as the main organic acid compound in WESMS and inhibited the fungal mycelium at a minimum concentration of 200 mg/l. In quantitative real-time PCR, the transcriptional expression of CaBPR1 (PR protein 1), CaBGLU (${\beta}$-1,3-glucanase), CaPR-4 (PR protein 4), and CaPR-10 (PR protein 10) were significantly enhanced on WESMS and DL-${\beta}$-aminobutyric acid (BABA) treated pepper leaves. In addition, the salicylic acid content was also increased 4 to 6 folds in the WESMS and BABA treated pepper leaves compared to water treated leaf sample. These findings suggest that WESMS of L. edodes suppress Phytophthora blight disease of pepper through multiple effects including antifungal activity, plant growth promotion, and defense gene induction.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.110.1-110
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• 2003

Control effect of grafting with rootstocks on Phythophthora blight of pepper was evaluated. The 40∼45 day old seedlings of five pepper cultivars, Wangdaeback, Jinmi, Boosa, Samsungcho and Pochunngchun, as a scion were grafted with ten species of root stocks. There wasn't graft incompatibility in all scion-root stock combinations. After 21 days from inoculation with Phytopkhora capsici, incidence of Phythophthora blight of plant grafted with Kataguruma, R-Safe, R-16, YCM 334 and SCM 334 of rootstocks tested was decreased by 64.6∼100％ compared to non-grafted plant whose disease severity was 3.7. However, plant grafted with Umsung native and Yeongdong native pepper was more sensitive to Phythophthora blight than non-grafed plant. Control effect by grafting was inversely proportional to virulence of inoculum and not significantly different among scion cultivars used. And resistant reaction of scion against Phytophthora blight was not affect that of scion-root stock plant in this study.

• Korean Journal of Plant Resources
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• v.21 no.4
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• pp.260-264
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• 2008

For the resistance test for Phytophthora blight of $T_1$ and $T_2$ transformants in pepper, Phytophthora blight fungus was inoculated to seedlings of the $T_1$ and $T_2$ transformants by concentration (density: zoospore $10^3/ml$). Occurrence rate of blight at 5days after inoculation was 4.0 % in T1-1 line and 10.0% in $T_1-2$ line, and its rate for 12 days after inoculation was 52.0% in $T_1-1$ line, 64.0% in $T_1-2$ line, respectively. Therefore, the lower occurrence rate to blight was enable to select resistant transformants in the some inoculation density (zoospore $10^3/ml$), meanwhile 'Kumtap' and 'Subicho' were 100% in highest occurrence rate to blight. For field test, in which blight was commonly occurred, of the Youngyang Pepper Experiment Station, the acquired transformant resisting to blight was similar to characteristics of domestic varieties, 'Subic ho' for fruit shape, but there are some differences in growth, days to flowering, fruit characteristics. Occurrence of blight in $T_2-1-6$, and $T_2-4-9$ lines was smaller approxmately 30% than commercial varieties, 'Kumtap', although occurrence of blight in field was showed higher difference among tested lines. In this study, we concluded that the transformants showing blight resistance selected from habitual field could be fixed at every generation, and the developed transformation system was also considered to develop transformants in pepper.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.102-107
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• 2005

To select microorganisms that exhibit antifungal activity against the fungal pathogens of pepper, Phytophthora capsici and Colletotrichum acutatum, soil samples from a forest and natural fields of Gajang-Dong, Sangju-city were tested in vitro and in vivo. Streptomyces griseofuscus 200401 was finally selected throughout antifungal activity test with dual culture, culture broth, and fruits. For the identification of the strain, nucleotide sequences of 16S rDNA and whole cell fatty acids were analyzed. It is like that the strain 200401 may be a novel biological control agent that can reduce application of chemical fungicides to control late blight and anthracnose on pepper.