• Research in Plant Disease
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• v.24 no.2
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• pp.87-98
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• 2018

The fungal species contain diverse transposable elements and repetitive sequences up to ~10% of their genome. It has been reported that distribution of transposable elements tends to correlate with the host range of the pathogen. Moreover, transposable elements cause the loss of an avirulence gene in the pathogen, which resulted in disease on a resistance cultivar. Thus, the transposable elements in the fungal pathogens may be one of the key factors driving the plant-fungus interactive evolution. In this article, we reviewed classification and biological functions of transposable elements in Magnaporthe species.

• The Plant Pathology Journal
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• v.31 no.1
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• pp.72-77
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• 2015

Spot blotch caused by the hemibiotrophic pathogen Cochliobolus sativus has been the major yield-reducing factor for barley production during the last decade. Monitoring transcriptional reorganization triggered in response to this fungus is an essential first step for the functional analysis of genes involved in the process. To characterize the defense responses initiated by barley resistant and susceptible cultivars, a survey of transcript abundance at early time points of C. sativus inoculation was conducted. A notable number of transcripts exhibiting significant differential accumulations in the resistant and susceptible cultivars were detected compared to the non-inoculated controls. At the p-value of 0.0001, transcripts were divided into three general categories; defense, regulatory and unknown function, and the resistant cultivar had the greatest number of common transcripts at different time points. Quantities of differentially accumulated gene transcripts in both cultivars were identified at 24 h post infection, the approximate time when the pathogen changes trophic lifestyles. The unique and common accumulated transcripts might be of considerable interest for enhancing effective resistance to C. sativus.

• KSBB Journal
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• v.8 no.4
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• pp.351-357
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• 1993

Three immobilization techniques and free cell system were tested to determine the most effective technique for the treatment of pulp waste effluent. The tests were conducted using Phanerochaete chrysosporium as a biocatalyst in a process designed to treat pulp waste effluent. The results show that Ca-alginate gel was the best immobilization material. The chosen material improved the stability and increased the removal efficiency of the system. The experiment using the chosen material was mom- bored for 400 hours with no significant changes in the state of the fungus. Common problems with other immobilization materials and free cell system were oxygen transfer resistance caused by air channelling and clogging in the bioreactor.

• Mycobiology
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• v.46 no.1
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• pp.33-46
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• 2018

Gray mold (Botrytis cinerea) is one of the most common diseases of strawberries (Fragaria${\times}$ananassa Duchesne) worldwide. Although many chemical fungicides are used for controlling the growth of B. cinerea, the risk of the fungus developing chemical resistance together with consumer demand for reducing the use of chemical fungicides have necessitated an alternative method to control this pathogen. Various naturally occurring microbes aggressively attack plant pathogens and benefit plants by suppressing diseases; these microbes are referred to as biocontrol agents. However, screening of potent biocontrol agents is essential for their further development and commercialization. In this study, 24 strains of yeast with antagonistic ability against gray mold were isolated, and the antifungal activity of the volatile and diffusible metabolites was evaluated. Putative mechanisms of action associated with the biocontrol capacity of yeast strains against B. cinerea were studied through in vitro and in vivo assays. The volatile organic compounds produced by the Galactomyces candidum JYC1146 could be useful in the biological control of plant pathogens and therefore are potential alternative fungicides with low environmental impact.

• YAKHAK HOEJI
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• v.57 no.6
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• pp.383-387
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• 2013

In the present study, we determined the antifungal effect of obacunone isolated from Phellodendri Cortex against Candida ablicans, a pathogenic fungus. The antifungal effect was analyzed by an in-vitro susceptibility test and in a murine model of disseminated candidiasis. Possible mechanism of the antifungal activity was also examined. Analyses of data resulting from the susceptibility test revealed that the compound inhibited C. albicans growth. At 25 ${\mu}g$ obacunone/ml, there was app. 45% reduction of CFUs (colony forming units) as compared to obacunone-untreated C. albicans yeast cells (P<0.01). In the murine model of disseminated candidiasis due to C. albicans, obacunone enhanced resistance of mice against disseminated candidiasis. During an entire period of 30-day observation, control animals all died within 14 days, whereas 60% of obacunone-treated mice survived (P<0.05). In addition, obacunone inhibited the hyphal production, a major virulence factor of C. albicans, from the blastoconidial form. Thus, obacunone appears to have antifungal activity for C. albicans infection. This may possibly be mediated by the blockage of hyphal production.

• Molecules and Cells
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• v.44 no.9
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• pp.670-679
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• 2021

Vesicle-associated membrane proteins 721 and 722 (VAMP721/722) are secretory vesicle-localized arginine-conserved soluble N-ethylmaleimide-sensitive factor attachment protein receptors (R-SNAREs) to drive exocytosis in plants. They are involved in diverse physiological processes in plants by interacting with distinct plasma membrane (PM) syntaxins. Here, we show that synaptotagmin 5 (SYT5) is involved in plant defense against Pseudomonas syringae pv tomato (Pst) DC3000 by regulating SYP132-VAMP721/722 interactions. Calcium-dependent stimulation of in vitro SYP132-VAMP722 interaction by SYT5 and reduced in vivo SYP132-VAMP721/722 interaction in syt5 plants suggest that SYT5 regulates the interaction between SYP132 and VAMP721/722. We interestingly found that disease resistance to Pst DC3000 bacterium but not to Erysiphe pisi fungus is compromised in syt5 plants. Since SYP132 plays an immune function to bacteria, elevated growth of surface-inoculated Pst DC3000 in VAMP721/722-deficient plants suggests that SYT5 contributes to plant immunity to Pst DC3000 by promoting the SYP132-VAMP721/722 immune secretory pathway.

• Research in Plant Disease
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• v.25 no.3
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• pp.103-107
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• 2019

Roles of nutrients in controlling plant diseases have been documented for a long time. Among the nutrients having impact on susceptibility/resistance to crop diseases, nitrogen is one of the most important nutrients for plant growth and development. In rice plants, excess nitrogen via fertilization in agricultural systems is known to increase susceptibility to the rice blast disease. Mechanisms underlying such phenomenon, despite its implication in yield and sustainable agriculture, have not been fully elucidated yet. A few research efforts attempted to link nitrogen-induced susceptibility to concomitant changes in rice plant and rice blast fungus in response to excess nitrogen. However, recent studies focusing on phytobiome are offering new insights into effects of nitrogen on interaction between plants and pathogens. In this review, I will first briefly describe importance of nitrogen as a key nutrient for plants and what changes excess nitrogen can bring about in rice and the fungal pathogen. Next, I will highlight some of the recent phytobiome studies relevant to nitrogen utilization and immunity of plants. Finally, I propose the hypothesis that changes in phytobiome upon excessive nitrogen fertilization contribute to nitrogen-induced susceptibility, and discuss empirical evidences that are needed to support the hypothesis.

• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.1-9
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• 2021

Human prostate cancer is the second most frequently diagnosed cancer worldwide, and its incidence rate continues to increase. Advanced prostate cancer is more difficult to treat than early forms due to its chemotherapy resistance. There is need for more effective agents that can inhibit the progression of advanced prostate cancer. Demethoxyfumitremorgin C (DMFTC) was isolated from the fermentation extract of the marine fungus Aspergillus fumigatus. Antiproliferative activity of DMFTC against human prostate cancer PC3 cells was examined through cell cycle analysis by flow cytometry, the fluorescent nuclear imaging analysis with propidium iodide (PI), and proteins expression related to cell cycle arrest and apoptosis were investigated via Western blotting. DMFTC inhibited PC3 cells growth through G1 phase cell cycle arrest and apoptosis induction. It activated the tumor suppressor p53 and the Cdk inhibitor p21, which regulate the cell progression into the G1 phase. Additionally, PI-positive late apoptotic non-viable cells were increased and the expression levels of the G1-positive downstream regulators cyclin D, cyclin E, Cdk2, and Cdk4 were decreased by DMFTC treatment. These results suggest that DMFTC induces G1 arrest and apoptosis induction through regulation of p53/p21-dependent cyclin-Cdk complexes, and it may be a useful therapeutic agent for the treatment of human advanced prostate cancer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.2
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• pp.118-125
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• 1978

To find out highly resistant gene source to black rot fungus in sweetpotato varieties, a screening test was carried out with inoculated tubers and sprouts in 1976 and 1977. Fifteen varieties out of 165 and 54 varieties out of 161 were highly resistant to black rot in the tuber and sprout tests. respectively. The sprout test showed bigger variation from year to year compared to tuber test. Varieties highly resistant to black rot in both tuber and sprout tests were Suweon # 59, #81, #90, Norin #17, #23. Chilship-il cho, Sachun Jong #36, Hamkao, and Kandee.

• The Korean Journal of Mycology
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• v.5 no.1
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• pp.13-19
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• 1977

In order to investigate histopathologically the nature of varietal resistance and infection process of the rice bast fungus, Pyricularia oryzae. this experiment was undertaken by using the resistant cultivar Tongil and susceptible cultivars Norin No.6 and Jinheung in 1973 to 1974. 1) It was found that appressorium of the fungus forms not only at 4 hours after incubation under the favorable conditions but also peak of appressorial formation is at 48 hours treatment. Physical stimulus known to be a definite factor for appressorial formation. The optimum temperature range for appressorial infection was at $24^{\circ}C$ to $28^{\circ}C$, and pH was between 4.8 to 8.0 with 6.8 as the optimum. 2) Although percent of appressorial formation on the leaves of resistant Tongil and susceptiible Norin No.6 were only slightly different, there was a remarkable difference between resistant and susceptible cultivars with regard to percent of hyphal infection and index for hyphal extension. Index of hyphal extension was 1.6-2.7 in Tonyil. while in susceptible cultivar was 3.4-6.6. The rate of discoloration of infected cells, a indication of hypersensitivity, was greater in the resistant than in susceptible cultvar. 3) Therefore, it could be concluded that resistance of Tongil cultivar may be attributable to a higher degree of mechanical barriers as well as a higher level of antifungal substance accumulation.