• Horticultural Science & Technology
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• v.35 no.4
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• pp.499-509
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• 2017

Recently, there has been increased attention to the development of new plant cultivars with enhanced resistance to biotic and abiotic stress. To develop ginseng cultivars with such traits, systematic breeding programs and comprehensive field studies are prerequisites. In this study, we applied a pure-line selection method to identify a ginseng cultivar with enhanced stress resistance. Phenotypic and agronomic characteristics, seed yield, and physiological responses to biotic and abiotic stresses were investigated according to the guidelines of the International Union for the Protection of New Varieties of Plants (UPOV). In the newly developed 'Kowon' cultivar, the time of emergence, flowering, and berry maturity were intermediate between those of the controls, 'Yunpoong' and 'Chunpoong'. The stem length of 'Kowon' was intermediate, whereas the root length was shorter and the main root diameter was greater than those of 'Chunpoong'. In local adaptability tests conducted in three regions, the yield of 'Kowon' was $666kg{\cdot}10a^{-1}$; 27% and 4% higher than that of 'Chunpoong' and 'Yunpoong'. Diseases such as Alternaria blight, Phytophthora blight, mulberry mealybug, and nematode infestation did not occur in 'Kowon'; and it also exhibited moderate resistance to damping-off and anthracnose. In these cases, yellow spots occurred on aerial parts and the rusty skin of the root, and it exhibited moderate resistance at high temperatures. Our study demonstrates that 'Kowon', which has a high root weight and enhanced biotic/abiotic stress resistance, is a superior cultivar that could increase farmers' income.

• Journal of Ginseng Research
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• v.32 no.4
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• pp.300-304
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• 2008

Cysteine proteinases play an essential role in plant growth and development but also in senescence and programmed cell death. They participate in both anabolic and catabolic processes. In addition, they are involved in signalling pathways and in the response to biotic and abiotic stresses. A cDNA clone encoding cysteine proteinase (CP) gene, designated PgCysP1, was isolated from Panax ginseng C. A. Meyer. Reverse transcriptase (RT)-PCR results showed that PgCysP1 expressed at different level in P. ginseng hairy root. Different stresses such as biotic as well as abiotic stresses triggered a significant induction of PgCysP1. The positive responses of PgCysP1 to the various stimuli suggested that PgCysP1 may help to protect the plant against reactive environmental stresses.

• Korean Journal of Medicinal Crop Science
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• v.17 no.4
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• pp.266-272
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• 2009

Cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.95), catalyzes the reduction of hydroxycinnamaldehydes to give hydroxycinnamyl alcohols, or "monolignols," the monomeric precursors of lignin. Lignins are important components of cell walls and lignified secondary cell walls play crucial roles in long distance transport of water and nutrients during plant growth and development and in plant defense against biotic and abiotic stresses. Here a cDNA clone containing a CAD gene, named as PgCAD, was isolated from a commercial medicinal plant Panax ginseng. PgCAD is predicted to encode a precursor protein of 177 amino acid residues, and its sequence shares high homology with a number of other plant CADS. The expression of PgCAD in adventitious roots and hairy roots of P. ginseng was analyzed using reverse transcriptase (RT)-PCR under various abiotic stresses such as salt, salicylic acid, wounding and chilling treatment that triggered a significant induction of PgCAD at different time points within 2-48 h post-treatment. This study revealed that PgCAD may help the plants to survive against various abiotic stresses.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.281-292
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• 2016

Plants can recognize and respond in various ways to diverse environmental stresses, including pathogenic microorganisms, salt, drought, and low temperature. Salicylic acid (SA) is one phytohormone that plays important roles in the regulation of plant growth and development. Nonexpressor of pathogenesis-related genes 1 (NPR1) was originally identified as a core protein that could function as a transcriptional co-regulator and SA receptor during systemic acquired resistance (SAR), a plant immune response that could activate PR genes after pre-exposure of a pathogen. Although the function of NPR1 in plant defense response and the role of SA hormone in the regulation of plant physiological processes have been well characterized, the biological role of NPR1 in plant abiotic stress responses is largely unknown. In this review, we will summarize and discuss the current understanding of NPR1 function in response to plant environmental stresses.

• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.53-58
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these "environmental or abiotic stresses", which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity, In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.n factors.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.1-11
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• 2016

Single nucleotide polymorphism (SNP) is an abundant form of genetic variation within individuals of species. DNA polymorphism can arise throughout the whole genome at different frequencies in different species. SNP may cause phenotypic diversity among individuals, such as individuals with different color of plants or fruits, fruit size, ripening, flowering time adaptation, quality of crops, grain yields, or tolerance to various abiotic and biotic factors. SNP may result in changes in amino acids in the exon of a gene (asynonymous). SNP can also be silent (present in coding region but synonymous). It may simply occur in the noncoding regions without having any effect. SNP may influence the promoter activity for gene expression and finally produce functional protein through transcription. Therefore, the identification of functional SNP in genes and analysis of their effects on phenotype may lead to better understanding of their impact on gene function for varietal improvement. In this mini-review, we focused on evidences revealing the role of functional SNPs in genes and their phenotypic effects for the purpose of crop improvements.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.81.1-81
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• 2003

Although plants have evolved to possess various defense mechanisms from local biotic and abiotic stressors, most of yield loss is caused by theses stressors. Recent studies have revealed that several different stress responsive reactions are inter-networking. Therefore, the identification and dissection of stress responsive genes is an essential and first step towards understanding of the global defense mechanism in response to various stressors. For this purpose, we applied cDNA microarray analysis, because it has powerful ability to monitor the global gene expression in a specific situation. To date, more than 10,000 non-redundant genes were identified from seven different cDNA libraries and deposited in our EST database (http://plant.pdrs.re.kr/ks200201/pepper.html). For this study, we have built 5K cDNA microarray containing 4,685 unigene clones from three different cDNA libraries. Monitoring of gene expression profiles of hot pepper interactions with biotic stress, abiotic stresses and chemical treatments will be presented. Although this work shows expression profiling at the sub-genomic level, this could be a good starting point to understand the complexity of global defense mechanism in hot pepper.

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.240-240
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• 2018

• The Plant Pathology Journal
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• v.39 no.6
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• pp.538-547
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• 2023

Rapid apple decline (RAD) is a complex phenomenon affecting cultivated apple trees and particularly dwarf rootstocks on grafted young apple trees. Since its first appearance in the United States, RAD has been reported worldwide, for example in Canada, South America, Africa, and Asia. The phenomenon has also been observed in apple orchards in Korea, and it presented similar symptoms regardless of apple cultivar and cultivation period. Most previous reports have suggested that RAD may be associated with multiple factors, including plant pathogenic infections, abiotic stresses, environmental conditions, and the susceptibility of trees to cold injury during winter. However, RAD was observed to be more severe and affect more frequently apple trees on the Malling series dwarf rootstock. In this study, we reviewed the current status of RAD worldwide and surveyed biotic and abiotic factors that are potentially closely related to it in Korea.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.360-365
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• 2004

Rehmannia glutinosa shows a high level of resistance to the non-selective herbicide paraquat. To characterize the antioxidant enzyme system of R. glutinosa, we comparatively examined the responses of antioxidant enzymes to UV, wounding and a general elicitor yeast extract in R. glutinosa and soybean. The levels of enzyme activities of the two plant species were drastically different between those per fresh weight (general activity) and per protein (specific activity) bases. The general activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and glutathione reductase (GR) were lower, but that of ascorbate peroxidase (APX) was higher in R. glutinosa than in soybean. The specific activities of the enzymes, however, were about two- to seven-fold higher in R. glutinosa than in soybean, except that of CAT, which was about 12-fold higher in soybean. The general and specific enzyme activities of R. glutinosa relative to those of soybean showed a consistent increase in responses to the stresses only in SOD. The specific activities of SOD and APX were higher in R. glutinosa in all stress treatments. The results might suggest a relatively higher contribution of SOD and APX to the stress tolerance.