• Journal of Wetlands Research
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• v.22 no.2
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• pp.113-120
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• 2020

For the conservation of both Sericinus montela (vulnerable species by red book of Korea) and A. contorta, we investigated environmental factors affecting the growth and reproduction of Aristolochia contorta. We selected four A. contorta habitats at Gapyeong, Pyeongtaek, Cheongju, and Yeoju in Korea and surveyed community and habitat characteristics of companion species, herbivore appearance, support types, and soil physicochemical properties in July and October, 2018. Habitat environments and the growth and reproduction characteristics of A. contorta were different according to four habitats of different regions. In particular, the fastest growth speed and earliest flowering and fruiting were observed in Pyeongtaek. Growth of A. contorta in Cheongju and Yeoju were interrupted by aboveground damage from human disturbance. In this study, support types seemed to be important for growth speed of A. contorta. Flowering and fruiting timing were likely to be related to combined effects of soil cation contents and competitive and herbivore stresses. Therefore, providing effective support and reducing biological stress should be necessary for stable growth and proper flowering and fruiting timing of A. contorta. In addition, experimental evidence would be needed to figure out the effect of soil cation and biological stress on flowering and fruiting of A. contorta in detail.

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.39-45
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• 2016

BACKGROUND: This study aimed to evaluate the combined effects of three components (NPK) of chemical fertilizers with basal application of compost on soil organisms.METHODS AND RESULTS: The soil was treated with five treatments continuously for 15 years: control, PK, NK, NP and NPK. The application of N increased plant growth or biomass, and enhanced organic matter content in the soils. Levels of microbial phospholipid fatty acids (PLFAs) in the soils did not show marked differences among the soils treated with different treatments. However, the principal component analysis showed the changes in the structure of the microbial community in the soil, depending on treatments added. Nitrogen application caused a decrease of pH and an increase of EC in the soils, and these environmental stresses appeared to offset the promoting effect of increased organic matter content on microbial abundance. The abundance of bacterivorous nematodes was the highest in the soils after treating NPK; however, the abundance of fungivorous nematodes was unaffected. There was no significant correlation between the abundances of microbial groups and their feeders. Organic matter content was significantly correlated with the abundance of nematodes in the soils.CONCLUSION: Our results showed that chemical fertilizers affect the soil food chains through both biotic and abiotic factors, and a trophic cascade in the soils may not occur in response to long-term fertilization.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.272-280
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• 2016

Chrysanthemum is one of the top floriculture species with ornamental and medicinal value. Although chrysanthemum breeding program has contributed to the development of various cultivars so far, it needs to be advanced from the traditional phenotype-based selection to marker-assisted selection (molecular breeding) as shown in major cereal and vegetable crops. Molecular breeding relies on trait-linked molecular markers identified from genetic, molecular, and genomic studies. However, these studies in chrysanthemum are significantly hampered by the reproductive, genetic, and genomic properties of chrysanthemum such as self-incompatibility, inbreeding depression, allohexaploid, heterozygosity, and gigantic genome size. Nevertheless, several genetic studies have constructed genetic linkage maps and identified molecular markers linked to important traits of flower, leaf, and plant architecture. With progress in sequencing technology, chrysanthemum transcriptome has been sequenced to construct reference gene set and identify genes responsible for developments or induced by biotic or abiotic stresses. Recently, a genome sequencing project has been launched on a diploid wild Chrysanthemum species. The massive sequencing information would serve as fundamental resources for molecular breeding of chrysanthemum. In this review, we summarized the current status of molecular genetics and genomics in chrysanthemum and briefly discussed future prospects.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.296-302
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• 2017

Rice (Oryza sativa) cultivars show an impairment of growth and development in response to abiotic stresses such as drought, salinity, heat and cold at the early seedling stage. The tolerance to heat stress in plants has been genetically modulated by the overexpression of heat shock transcription factor genes or proteins. In addition to a high temperature-tolerance that has also been altered by elevating levels of osmolytes, increasing levels of cell detoxification enzymes and through altering membrane fluidity. To examine the heat tolerance in transgenic rice plants, three OsOPT10 overexpressing lines were characterized through a physiological analysis, which examined factors such as the electrolyte leakage (EL), soluble sugar and proline contents. We further functionally characterized the OsOPT10 gene and found that heat induced the expression of OsOPT10 and P5CS gene related proline biosynthesis. It has been suggested that the expression of OsOPT10 led to elevated heat tolerance in transgenic lines.

• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.323-328
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• 2003

Soil salinity is one of the most serious abiotic stresses limiting the productivity of agricultural crops. To cope with salt stress, plants respond with physiological, developmental and biochemical changes, including the synthesis of a number of proteins and the induction of gene expression. Salicornia herbacea is a halophytic plant that grows in salt marshes and on muddy seashores. In order to understand the biochemical and molecular mechanisms of salt tolerance in S. herbacea, we isolated several genes that involved in the salt tolerance by mRNA differential display. Here we report the cloning of a cDNA encoding fructose-1, 6-bisphosphate aldolase, named ShADL, which is 1293 bp long and contains an open reading frame consisted of 359 amino acids with calculated molecular mass of 39 kDa. ShADL protein showed 86％ identity with Arabidopsis and 78％ with aldolase of common ice plant. Northern blot analysis revealed that the transcript of ShADL gene was increased dramatically depending on the NaCl concentrations.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.299-306
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• 2009

Oxidative stress is the main limiting factor in crop productivity. To solve global environmental problems using the plant biotechnology, we have developed on the oxidative stress-tolerant transgenic tall fescue plants via Agrobacterium-mediated genetic transformation method. In order to develop transgenic tall fescue (Festuca arundinacea Schreb.) plants with enhanced tolerance to multiple environmental stresses, nucleotide diphosphate kinase gene under the control of CaMV35S promoter were introduced into genome of tall fescue plants. Proteomic analysis revealed that transgenic tall fescue not only accumulated NDP kinase 2 protein in their cells, but also induced several other antioxindative enzyme-related proteins. When leaf discs of transgenic plants were subjected to cold stress, they showed approximately 30% less damage than wild-type plants. In addition, transgenic tall fescue plants showed normal growth when transgenic plants were subjected to $4^{\circ}C$ for 3 days treatments. These results suggest that transgene is important in ROS scavenging by induction of antioxidative proteins, and could improve abiotic stress tolerance in transgenic tall fescue plants.

• Journal of Ginseng Research
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• v.38 no.4
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• pp.270-277
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• 2014

Background: The effect of methyl jasmonate (MJ) on ginsenoside production in different organs of ginseng (Panax ginseng Meyer) was evaluated after the whole plant was dipped in an MJ-containing solution. MJ can induce the production of antioxidant defense genes and secondary metabolites in plants. In ginseng, MJ treatment in adventitious root resulted in the increase of dammarenediol synthase expression but a decrease of cycloartenol synthase expression, thereby enhancing ginsenoside biosynthesis. Although a previous study focused on the application of MJ to affect ginsenoside production in adventitious roots, we conducted our research on entire plants by evaluating the effect of exogenous MJ on ginsenoside production with the aim of obtaining new approaches to study ginsenoside biosynthesis response to MJ in vivo. Methods: Different parts of MJ-treated ginseng plants were analyzed for ginsenoside contents (fine root, root body, epidermis, rhizome, stem, and leaf) by high-performance liquid chromatography. Results: The total ginsenoside content of the ginseng root significantly increased after 2 d of MJ treatment compared with the control not subjected to MJ. Our results revealed that MJ treatment enhances ginsenoside production not in the epidermis but in the stele of the ginseng root, implying transportation of ginsenosides from the root vasculature to the epidermis. Application of MJ enhanced protopanaxadiol (PPD)-type ginsenosides, whereas chilling treatment induced protopanaxatriol (PPT)-type ginsenosides. Conclusion: These findings indicate that the production of PPD-type and PPT-type ginsenosides is differently affected by abiotic and biotic stresses in the ginseng plant, and they might play different defense mechanism roles.

• Korean Journal of Plant Resources
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• v.19 no.5
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• pp.634-639
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• 2006

In order to develop a disease-resistant root stock for the growth of watermelon, an efficient regeneration system of the gourd(Lagenaria leucantha Duch.) inbred line GO701-2 via organogenesis was established in this experiment. Using proximal parts of cotyledon explant excised from germinated seedling in vitro, maximum adventitious shoot formation (39%) was achieved on MS medium where cytokinin (BA) and auxin (IAA) were added at a concentration of 3mg/L and 0.1mg/L, respectively. Roots of the elongated shoots were successfully formed on MS medium without adding any plant growth regulators. The cucumber CsGolS1 gene known as a resistance gene against biotic and abiotic stresses, was constructed into the binary vector pBI121 under the control of CaMV 35S promoter. When the gene was introduced into the genome of gourd by Agrobacterium-mediated transformation, putative transgenic plants were obtained with the transformation efficiency of approximately 20 percent.

• Journal of Life Science
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• v.18 no.3
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• pp.304-310
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• 2008

Heat shock protein 70 (HSP70) is known as molecular chaperone, the fundamental protein participating in various processes, from nascent protein synthesis to protection of proteins during abiotic stresses and developmental programs. However, their biological functions in plants are not yet well known. Here, NtHSP70-1 (AY372069), HSP70 of Nicotiana tabacum induced by heat stress was investigated. To analyze the protective role of NtHSP70-1, transgenic tobacco plants, which constitutively overexpressed NtHSP70-1 as well as contained either the vector alone or having NtHSP70-1 in the antisense orientation, were constructed. The altered NtHSP70-1 levels in plants were confirmed by western blotting and transgenic sense lines exhibited tolerance to heat stress. Seedlings with the constitutively expressed NtHSP70-1 grew as green or healthy plants after heat stress. In contrast, transgenic vector or antisense lines exhibited yellowing of leaves or some delay in growth, which finally led to death. Evaluation of chlorophyll contents of heat-shocked transgenic tobacco seedlings indicated that NtHSP70-1 contributes to thermotolerance by preventing chlorophyll synthesis in plants.

• Journal of Life Science
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• v.23 no.4
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• pp.487-494
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• 2013

An AlaAT knock-out mutant (alaat) of rice (Oryza sativa L.) was isolated from T-DNA tagging lines and the genotypes of its progeny were determined with AlaAT1-specific primers. The alaat phenotypes showed decreased growth and grain yield when compared with control plants. The activity of AlaAT1 in the mutant plants was practically undetectable. The responses of alaat plants to growth under salt stress were compared with those of control plants by measuring chlorophyll fluorescence and the activities and mRNA expression of antioxidant enzymes. All abiotic stresses tested (salt, drought, and chilling) caused a similar decrease in chlorophyll fluorescence in both alaat and wild type plants. The activity of peroxidase (POX), an antioxidant enzyme, decreased following salt treatment of alaat plants, while control plant showed an increased activity. The mRNA levels for cAPX (cytosolic ascorbate peroxidase), POX2, and AlaAT were determined by RT-PCR following salt stress. No AlaAT1 mRNA was detected in alaat plants. The POX2 mRNA showed a slightly increased level in the wild type but was not detected in alaat plants, in agreement with the activity assays. The levels of cAPX mRNA were greatly increased in both the wild type and alaat plants. The salt stress effects on rice plant growth are therefore proposed to reflect a loss of function of AlaAT, which alters the activity and synthesis of antioxidant enzymes (especially peroxidases), rather than a direct effect on photosynthesis.