• The Plant Pathology Journal
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• v.37 no.2
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• pp.99-114
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• 2021

Tan spot of wheat, caused by Pyrenophora tritici-repentis (Ptr), results in a yield loss through chlorosis and necrosis of healthy leaf tissue. The major objective of this study was to compare gene expression in resistant and susceptible wheat cultivars after infection with Ptr ToxA-producing race 2 and direct infiltration with Ptr ToxA proteins. Greenhouse experiments included exposure of the wheat cultivars to pathogen inoculum or direct infiltration of leaf tissue with Ptr-ToxA protein isolate. Samples from the experiments were subjected to RNA sequencing. Results showed that ToxA RNA sequences were first detected in samples collected eight hours after treatments indicating that upon Ptr contact with wheat tissue, Ptr started expressing ToxA. The resistant wheat cultivar, in response to Ptr inoculum, expressed genes associated with plant resistance responses that were not expressed in the susceptible cultivar; genes of interest included five chitinases, eight transporters, five pathogen-detecting receptors, and multiple classes of signaling factors. Resistant and susceptible wheat cultivars therefore differed in their response in the expression of genes that encode chitinases, transporters, wall-associated kinases, permeases, and wound-induced proteins, among others. Plants exposed to Ptr inoculum expressed transcription factors, kinases, receptors, and peroxidases, which are not expressed as highly in the control samples or samples infiltrated with ToxA. Several of the differentially expressed genes between cultivars were found in the Ptr resistance QTLs on chromosomes 1A, 2D, 3B, and 5A. Future studies should elucidate the specific roles these genes play in the wheat response to Ptr.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.237-246
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• 2015

Heavy metal pollution in soil, such as lead contamination, has become an area of interest in Korea because of urbanization and atmospheric deposition from neighboring countries. Therefore, in this research, eco-physiological responses such as chlorophyll contents, antioxidant enzyme activity, photosynthetic rate, biomass and phytoaccumulation abilities were investigated for 4 commonly used native roadside tree species to suggest suitable tree species to cope with lead contamination. The target species, Ginkgo biloba, Prunus yedoensis, Zelkova serrata and Chionanthus retusus showed lead toxicity by significant changes of chlorophyll contents and antioxidant enzyme activities on treatments over 200 mg Pb/kg. However, biomass and photosynthetic rates only showed significant responses of plants in the highest level (5,000 mg/kg) treatment. Especially, G. biloba did not show any significant changes of antioxidant enzyme activity, photosynthetic rate, and biomass even in the highest level treatment. In low level - environmentally realistic treatments, G. biloba and P. yedoensis showed the highest phytoaccumulation rate of lead from soil. Selecting and planting species like G. biloba which have good phytoaccumulation abilities and resistance to lead contamination by further research will be required to deal with emerging lead contamination.

• The Korean Journal of Mycology
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• v.49 no.1
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• pp.33-44
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• 2021

Lentinula edodes (Berk.) Pegler, the most produced mushroom in the world, is an edible mushroom with very high nutritional and pharmacological value. Currently, interest in the protection of genetic resources is increasing worldwide, and securing the distinction between new cultivars is very important. Therefore, the development of efficient molecular markers that can discriminate between L. edodes cultivars is required. In this study, we developed cleaved amplified polymorphic sequence (CAPS) markers for the identification of L. edodes cultivars (Sanbaekhyang and Sulbaekhyang). These markers were developed from whole genome sequencing data from L. edodes monokaryon strain B17 and resequencing data from 40 cultivars. A nucleotide deletion existed in scaffold 19 POS 214449 in Sanbaekhyang (GT→G), and a single nucleotide polymorphism changed in scaffold 7 POS 215801 in Sulbaekhyang (G→A). The restriction enzymes Hha I and HpyCH4IV distinguished Sanbaekhyang and Sulbaekhyang, respectively, from other cultivars. Thus, we developed two CAPS markers for the identification of the L. edodes cultivars Sanbaekhyang and Sulbaekhyang.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.2
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• pp.57-60
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• 2007

Interest in chum salmon(Oncorhynchus keta) biology I Korea has increased since the establishment of the Yangyang Inland Hatchery of the National Fisheries Research and Development Institute during mid 1980s. The enhancement program of chum salmon was expanded thereafter, so that chum salmon were transplanted 18 streams in the coast of the Korean Peninsula. However, ecological research on salmon species was very limited due to the lack of a research program. Though involvement in the North Pacific Anadromous Fish Commission (NPAFC) requires scientific investigation on salmon research of each member nation, no conspicuous increase in research funding was achieved in Korea. Oceanic environments have been rapidly altered by climate change during the last a few decades and ocean ecosystems including salmon populations will be modified by global warming. Special attention is needed for stocks near the southern boundary of distribution, such as Korean chum salmon. This special issue is the venue for reviewing ongoing researches in Korea, and we hope that this issue will be a big step toward active ecological research in Korea under changing environments.

• Journal of Korean Elementary Science Education
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• v.40 no.2
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• pp.239-252
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• 2021

The purpose of this study is to develop an evolutionary STEAM education program based on the brain and to analyze its effects on scientific interest and scientific creativity of elementary school students. Four different topics based on four scientific fields (Physics, Chemistry, Biology and Earth Science) were derived from the science textbook under the 2015 revised curriculum to build a brain-based evolutionary STEAM education program. The research subjects were 90 fourth graders of S-elementary school located in Gyeonggi Province, Korea and they were divided into an experimental group of 45 students and a comparative group of 45 students. The main findings of this study are as follows. First, according to the independent samples t-test of scientific interest, no statistically significant difference were found between the two groups, but the brain-based evolutionary STEAM education had meaningful effect on improving 'interest in scientific learning' and 'anxiety about scientific learning'. Second, according to the paired samples t-test of scientific interest, the experimental group had significantly improved 'interest in science' but on the other hand, there was no effect on the comparative group. Third, scientific creativity and originality of the experimental group were significantly higher after the class than that of the comparative group. Fourth, although there were some significant differences between the two groups in scientific creativity after the class, both groups had improved scientific creativity between the results of pre and post test. Based on these results, we discuss implications for science education and STEAM education research.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.279-285
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• 2016

It has been established that different kinds of bacteria agents are involved in various cancers. Although the mechanism of tumorigenesis is not clearly understood, there is evidence for the presence of bacteria within tumors, with at least a progression effect for some bacteria that prepare suitable microenvironments for tumor cell growth. The aim of current study was to evaluate bacterial dysbiosis in sentinel lymph nodes of breast cancer patients. One hundred and twenty three fresh-frozen sentinel lymph nodes and a corresponding number of normal adjacent breast tissue specimens and five normal mastectomy samples were investigated employing RT-PCR. In addition using genus-specific primers were applied. There was a significant differences as presence of Methylobacterium radiotolerance DNA recorded between patients and normal control group (p= 0.0). Based on our research work, further studies into the role of microbes in breast cancer would be of great interest.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.3
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• pp.129-138
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• 2022

Reintroduction programs have been promoted across the world to recover and rehabilitate endangered birds through ex situ captive breeding and releasing to the nature. The ultimate aims of these reintroduction programs are recovery of sustainable populations in natural habitats. To ensure the success of the reintroduction programs, it is necessary to examine the followings in order to increase the success rate of releasing along with the development of captive breeding techniques: 1) Adequate habitat provision, 2) adaptability of captive-bred individuals, 3) survivability of released individuals, and 4) social interest and will. Before releasing captive-bred individuals, it should be reviewed whether there are habitats in which the limiting factor is removed, and assessed their long-term safety. The quantity and quality of the released individuals must be considered to increase the chances for mate selection, maintain genetic diversity, and acquire the ability to adapt to the wild. The release method must be decided in consideration of characteristics of the target habitats and individuals, and rational means such as careful observation, evaluation, and feedback must be provided throughout the release process. For the long-term success of recovery projects, social awareness, sustainable support, and related experts are needed. Satisfying these criteria can help to increase the success rates of reintroduction programs. For the bird reintroduction program in the future, the feasibility of the methods and procedures must be closely reviewed before starting.

• Microbiology and Biotechnology Letters
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• v.51 no.2
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• pp.135-146
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• 2023

Viral oncology is focused on understanding the relationship between cancer and viruses, which are known to play a role in the development of certain types of cancer. Approximately 15-20% of human cancers are believed to be caused by oncogenic viruses, and as a result, there is significant interest in understanding how these viruses contribute to cancer development. There are several viruses that have been linked to cancer, including human papillomavirus, hepatitis B and C virus, Epstein-Barr virus, human T-cell lymphotropic virus type 1, Kaposi's sarcoma-associated herpesvirus, and Merkel cell polyomavirus. Each of these viruses is associated with different types of cancer, and the mechanisms by which they contribute to cancer development are diverse. This article discusses these mechanisms as well as current and future strategies for preventing and treating virus-associated cancers with the goal of presenting a thorough review of the current state of knowledge in viral oncology and to highlight the importance of continued research in this field.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.3
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• pp.305-313
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• 1985

There is a trend that the total number of cancer cases is steadily increasing as the population grows. It has been estimated that 85% of the cancer rate in the U.S. is attributed to environmental factors. Among the environmental factors, diet and nutrition appear to be related to the largest number of human cancers. Diet and nutrition might be related to cancer by several mechanisms. Food may contain a direct carcinogen or precursors that become carcinogens by spontanous reactions, or by host metabolism, or through the actions of microbial flora. Chemicals that cause cancers generally have reactive electrophilic centers which can combine with electron-rich atoms in nucleic acids and cause cancers by changing the genetic activity of the cells. A variety of factors in foods might be involved in the etiology of carcinogenesis. Chemicals in food that cause cancers include carcinogens of plants and animal origin and also those in drinking water. Other then these, fungal metabolites alcohol, asbestos, heavy metals, pesticides, and food additives might be included as food carcinogenesis. The method of cooking foods also might contribute to carcinogenesis. Some chemicals in foods act as promoters in carcinogenesis. Prevention of cancers by dietary practises have received much interest. Consumption of certain vegetables or cellulose can reduce carcinogenic activity of several compounds. A variety of antioxidants or micronutrients may be effective anticarciongens. Glutathione in the soluble fraction of the cells, is a major defense against oxidative and alkylating carcinogens. Recently anticarcinogenic activity of chlorophyll was demonstrated. Daily consumption of milk appears to effectively reduce stomach cancer.

• BMB Reports
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• v.34 no.1
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• pp.43-46
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• 2001

$\alpha$-Phenyl-N-t-butylnitrone (PBN) is one of the most widely used spin-trapping compounds for investigating the existence of free radicals in biological systems. Recently, there has been considerable interest in the antioxidant nature of PBN on degenerative diseases, presumably related to oxidative stress. In the present study, the protective effect of PBN on the HepG2 cell line under oxidative stress was investigated. When the HepG2 cells were exposed to oxidant, such as hydrogen peroxide, menadione, or ethanol, the protective role of PBN was manifested as a reduction in trypan blue uptake and a decrease in the endogenous production of oxidants, as measured by the oxidation of 2',7'-dichlorodihydrofluorescin. The modulation of activity of major antioxidant enzymes, such as superoxide dismutase and catalase, was not significantly different either in the presence or in the absence of PBN. This indicates that PBN acts as a direct scavenger of reactive oxygen species.