Kuen Woo Park

Publications (4)4.18 Total impact

• Source

  Available from: escholarship.org

  Article: Chilling tolerance of cucumber (Cucumis sativus) seedling radicles is affected by radicle length, seedling vigor, and induced osmotic‐ and heat‐shock proteins

  Ho-Min Kang, Kuen-Woo Park, Mikal E. Saltveit
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  ABSTRACT: Cucumber seedling radicles decrease in chilling tolerance as they increase in length or decrease in vigor. The protein content of the apical 5 mm of the radicle decreased with decreases in chilling tolerance (R2 = 0.92). This general reduction in protein content was reflected in a decrease of six dehydrin-like proteins with apparent molecular weights of 13.0, 15.0, 16.8, 23.0, 26.8, and 33.5 kDa. The disappearance of naturally occurring dehydrin-like proteins in cucumber seedling radicles as they elongate or lose vigor was correlated with a loss of chilling tolerance. Exposure to an osmotic (0.6 M mannitol) or heat (2 min at 45°C) stress enhanced chilling tolerance. The osmotic-shock treatment induced both chilling tolerance and the appearance or strengthening of dehydrin-like proteins previously present in radicles. The heat-shock treatment also induced high levels of chilling tolerance and protein(s) that reacted with a 23 and 70 kDa antibody. However, these heat-shock protein (HSPs) did not cross react with the probe for dehydrin-like proteins. When organized into high, medium, and low chilling tolerance groups, radicle that were chilling tolerant contained either the 13.0 and 16.8 kDa dehydrin-like proteins, or the 15.0 and 23.0 kDa dehydrin-like proteins, or the 23 or 70 kDa HSP.
  Physiologia Plantarum 07/2005; 124(4):485 - 492. · 3.11 Impact Factor
• Article: Transgenic tobacco plants expressing the coat protein of cucumber mosaic virus show different virus resistance

  Ki Hyun Ryu, Gung Pyo Lee, Kuen Woo Park, Se Yong Lee, Won Mok Park
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  ABSTRACT: Transgenic tobacco (Nicotiana tabacum cv. Xanthi-nc) plants were regenerated after cocultivation of leaf explants withAgrobacterium tumefaciens strain LBA4404 harboring a plasmid that contained the coat protein (CP) gene of cucumber mosaic virus (CMV-As). PCR and Southern blot analyses revealed that the CMV CP gene was successfully introduced into the genomic DNA of the transgenic tobacco plants. Transgenic plants (CP+) expressing CP were obtained and used for screening the virus resistance. They could be categorized into three types after inoculation with the virus: virus-resistant, delay of symptom development, and susceptible type. Most of the CP+ transgenic tobacco plants failed to develop symptoms or showed systemic symptom development delayed for 5 to 42 days as compared to those of nontransgenic control plants after challenged with the same virus. However, some CP+ transgenic plants were highly susceptible after inoculation with the virus. Our results suggest that the CP-mediated viral resistance is readily applicable to CMV disease in other crops.
  Journal of Plant Biology 11/1998; 41(4):255-261. · 1.07 Impact Factor
• Article: Transmission of tobacco mosaic virus in recirculating hydroponic system

  Won Mok Park, Gung Pyo Lee, Ki Hyun Ryu, Kuen Woo Park
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  ABSTRACT: The possible pathway of transmission of tobacco mosaic virus (TMV) from diseased plants to healthy plants in two hydroponic systems, deep flow culture (DFC) and container culture (CC), was investigated in this study. The tested plants were tobacco (Nicotiana tabacum cv. Samsun-nn and cv. Xanthi), tomato (Lycopersicon esculentum cv. Alchan), and hot pepper (Capsicum annuum cv. Dahong). The longevity in vitro and the dilution end point of the virus in the hydroponic solution were 5 days and 10−4 (w/v), respectively. When inoculum source plants and tested healthy plants were grown side by side in the same gully or containers, typical TMV symptoms appeared on the tested plants in 2 weeks. The presence and concentration of the virus in the tissues of the tested plants could be detected by DAS-ELISA. It was noticed that roots of the inoculum source plants grafted to those of the tested plants during growing period. However, when both inoculated plants and healthy plants were grown separately, and their root tips were either removed or remained intact, no transmission of the virus from the inoculum source plants to the tested healthy plants occurred even though they shared the same recycled nutrient solution. These results indicate that the virus in a recirculating hydroponic system could be transmitted from virus-diseased plants to healthy plants mainly via root-tip grafting but was hardly transmitted through regularly renewed hydroponic nutrient solution.
  Scientia Horticulturae.
• Article: Elevated growing temperatures during the day improve the postharvest chilling tolerance of greenhouse-grown cucumber (Cucumis sativus) fruit

  Ho-Min Kang, Kuen-Woo Park, Mikal E. Saltveit
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  ABSTRACT: Growing cucumber fruit in a greenhouse at elevated temperatures during the day increased their tolerance to postharvest chilling. Fruit grown with an average day temperature of 32±1 °C (high temperature) had a storage life (i.e. time to loose 7% fresh weight) of 16 days at 10 °C and did not exhibit chilling injury, while fruit grown at 27±1 °C (control) developed symptoms of chilling injury (i.e. appearance of translucent, water-soaked areas in the mesocarp) after 12 days at 10 °C. The rate of fresh weight loss and the storage life (i.e. 7% water loss) of fruit from both treatments was 12 days when stored at 20 °C. Chilling-induced ion leakage from mesocarp disks was lower from high temperature grown fruit than from control fruit. During storage at 10 °C, firmness, vitamin C content, and activity of superoxide dismutase (SOD; EC 1.15.1.1), and catalase (CAT; EC 1.11.1.6) were higher in high temperature grown fruit than in control fruit. Enhanced antioxidant enzyme activity in high temperature grown fruit may have contributed to increased chilling tolerance.
  Postharvest Biology and Technology.