Youn-Sig Kwak

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Medicago truncatula is a fast-emerging model for the study of legume functional biology. We used the tobacco retrotransposon Tnt1 to tag the Medicago genome and generated over 7600 independent lines representing an estimated 190,000 insertion events. Tnt1 inserted on average at 25 different locations per genome during tissue culture, and insertions were(More)
In agro-ecosystems worldwide, some of the most important and devastating diseases are caused by soil-borne necrotrophic fungal pathogens, against which crop plants generally lack genetic resistance. However, plants have evolved approaches to protect themselves against pathogens by stimulating and supporting specific groups of beneficial microorganisms that(More)
Major diseases in grafted cacti have been reported and Fusarium oxysporum, Bipolaris cactivora, Phytophthora spp. and Collectotrichum spp. are known as causal pathogens. These pathogens can lead to plant death after infection. Therefore, some European countries have quarantined imported cacti that are infected with specific fungal pathogens. Consequently,(More)
Cankers are localized dead areas in the bark of stems, branches or twigs of many types of trees and shrubs, and are usually caused by fungi. We observed severe canker symptoms in oak trees located in Gyeongnam province in 2011. A total 31 trees were discovered with cankers of varied size, with an average of 48.5 × 15.2 cm. Black, half-rounded globular mound(More)
Anthracnose, caused by Colletotrichum gloeosporioides (C. gloeosporioides; Teleomorph: Glomerella cingulata), is the most destructive disease that affects sweet persimmon production worldwide. However, the biology, ecology, and genetic variations of C. gloeosporioides remain largely unknown. Therefore, in this study, the development of fungicide resistance(More)
Black spot of sweet persimmon, caused by Alternaria alternata, occurred in an orchard in Gyeongnam province, Korea in 2012. The symptom was appearance of 0.5 to 4 cm black spots on the surface of fruit. The pathogen was isolated from flesh of disease lesions. The causal agent was identified as A. alternata by morphological characteristics and sequencers of(More)
The tulip tree (Liriodendron chinense) has been widely cultivated in Korea as a street or garden tree for its large flowers, which have a superficial resemblance to tulips. Occurrence of anthracnose disease on the leaves of tulip trees growing on the campus of Gyeongsang National University, Jinju, Korea, has been observed. Based on mycological(More)
Strawberry bacterial angular leaf spot (ALS) disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are 20°C and the pathogen suffers mortality above(More)
Genome-wide screening of Saccharomyces cerevisiae revealed that signaling pathways related to the alkaline pH stress contribute to resistance to plant antimicrobial peptide, Pn-AMP1. Plant antimicrobial peptides (AMPs) are considered to be promising candidates for controlling phytopathogens. Pn-AMP1 is a hevein-type plant AMP that shows potent and(More)
Anthracnose symptoms were observed on leaves of red spider lilies in Korea. At the early stages of infection the symptoms appeared as small red spots on the leaves. In later stages, the infected leaves gradually turned yellow to brown and developed wilting symptoms. The pathogen isolated from the infected leaves of red spider lily was identified as C.(More)