• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.83-88
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• 2004

Expression of an anionic peroxidase swpa2 gene isolated from cultured cells of sweetpotato (Ipomoea batatas) was investigated under various stress conditions by RT-PCR. The swpa2 gene was not expressed in any tissues of intact sweetpotato plant grown at the normal condition. The expression of this gene was strongly induced in leaf tissue by treatment of $H_2O$$_2$ (440mM). Treatment of NaCl (100mM), ABA (0.1mM) and methyl jasmonate(MeJA, 0.1mM) also induced the expression of swpa2 gene. Interestingly, salicylic acid (SA, 0.1 mM) did not induce the expression of swpa2 gene, indicating that anionic swpa2 POD is differently involved in SA and MeJA signaling pathways. In addition, swpa2 gene was strongly induced in sweetpoato leaf tissues infected with Pectobacterium chrysanthemi, indicating that swpa2 is involved in defense related to the pathogenesis of P. chrysanthemi in sweetpotato plants. These results strongly suggest that swpa2 gene is involved in overcoming oxidative stresses caused by both abiotic and biotic stress.

• 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.

• 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.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.57-57
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• 2022

In many areas of the world, salt damage and drought have had a negative impact on human survival due to a decrease in agricultural productivity. For instance, about 50% of agricultural land will be affected by salt damage by 2050. Biostimulants such as plant extracts can not only increase the nutrient utilization efficiency of plants, but also promote plant growth and increase resistance to abiotic or biotic stress. Therefore, the objective of this study was to determine how selected plant extracts might reduce levels of stress caused by drought and salt and to better understand the physiological response mechanisms of rice plants. In this study, we used Soybean leaves, Soybean stems and Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts were used. These extracts had been used in previous studies and were found to be effective. The materials were dried in a dry oven at 50℃ for 5 days and ground using a blender. Each 50 g of materials was put in 1 L of distilled water, stirred for 24 hours, filtered using 4 layers of mirocloth, and then concentrated using a concentrator. Rice (cv. Hopumbyeo) seeds were immersed and germinated, and then sown in seedbeds filled with commercial soil. In drought experiments, three rice seedlings at 1 week after seeding was transplanted into 100 ml cups filled with commercial soils and grown until the 4-leaf stage. For this experiment, the soil weight in a cup was equalized, and water was allowed to become 100% saturated and then drained for 24 hours. Thereafter, plant extracts at 3% concentrations were applied to the soils. For NaCl treatments, rice plants at 17 days after seeding were treated with either 100 mM NaCl or plant extracts at 1%+ 100 mM NaCl combinations in the growth chamber. Leaf injury, relative water content, photosynthetic efficiency, and chlorophyll contents were measured at 3, 5, and 6 days after treatments. Shoot fresh weight of rice under drought conditions increased 28-37% in response to treatments of Soybean leaf, Soybean stem, Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts at 3% when compared with control plants. Shoot fresh weight of rice subjected to 100 mM NaCl treatments also increased by 6-24% in response to Soybean leaf, Soybean stem, Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts at 3% when compared with control plants. Compared to the control, rice plants treated with these six extracts and subjected to drought conditions had significantly higher relative water content, Fv/Fm, total chlorophyll and total carotenoids than control plants. With the exception of relative water contents, rice plants treated with the six extracts and subjected to salt stress (100 mM NaCl treatments) had significantly higher Fv/Fm, total chlorophyll and total carotenoids than control plants. However, the type of extract used did not produce significant difference in these parameters. Thus, all the plant extracts used in this study could mitigate drought and NaCl stresses and could also contribute substantially to sustainable crop production.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.2
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• pp.111-116
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• 2019

The biotic stress of garlic and tobacco infected by bacteria and virus was evaluated using a thermal imaging camera in a growth chamber. The remote sensing technique using the thermal camera detected that garlic leaf temperature increased when the leaves were infected by bacterial soft rot of garlic. Furthermore, the temperature of leaf was relatively high for the leaves where the colony-forming unit per mL was large. Such temperature patterns were detected for tobacco leaves infected by Cucumber Mosaic Virus using thermal images. In addition, the crop water stress index (CWSI) calculated from leaf temperature also increased for the leaves infected by the virus. The event such that CWSI increased by the infection of the virus occurred before visual disease symptom appeared. Our results suggest that the thermal imaging camera would be useful for the development of crop remote sensing technique, which can be applied to a smart farm.

• 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 the Korean Institute of Landscape Architecture
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• v.35 no.1 s.120
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• pp.88-93
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• 2007

Since the 1990s, the application of Kentucky bluegrass cultivars has increased in newly-constructed Korean golf courses as opposed to the previously-used zoysiagrass. However, there have been few reports studying the selection and characterization of these Kentucky bluegrass cultivars under Korean weather conditions. A total of 12 Kentucky bluegrass cultivars were tested for their adaptability in environmental stresses during summer conditions in Korea in order to select the best Kentucky bluegrass cultivars for use in Korean golf courses. This study found that two Kentucky bluegrass cultivars ('Midnight' and 'Bluestone') maintained their green throughout the summer season and had a high degree of root density, as compared to the other cultivars tested. These two cultivars also had a good rate of coverage in the early growth period. These characteristics make them suitable for application on sports fields and golf courses, which receive many divots and the frequent replacement of turfgrass sod caused by both biotic and abiotic stress. Two other cultivars, the 'Ginney' and 'Nuglade', also displayed good visual quality and high rate of coverage under summer conditions. In conclusion, the 'Midnight' and 'Bluestone' cultivars performed well in areas including the maintenance of their green color, the number of roots and the rate of coverage during the summer months. These characteristics are necessary for golf courses sports fields, which receive many divots and requirethe frequent replacement of turfgrass. further research on a range of Kentucky bluegrass cultivars, including a sensitivity test for many pathogens and recovery rates from a variety of stresses, is required in the near future.

• BMB Reports
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• v.38 no.4
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• pp.420-431
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• 2005

The differentially virulent race T1 of common bunt (Tilletia tritici) was used to inoculate the wheat lines Neepawa (compatible) and its sib BW553 (incompatible) that are nearly isogenic for the Bt-10 resistance gene. Inoculated crown tissues were used to construct a suppression subtractive hybridization (SSH) cDNA library. Of the 1920 clones arrayed from the SSH cDNA library, approximately 10% were differentially regulated. A total of 168 differentially up-regulated and 25 down-regulated genes were identified and sequenced; 71% sequences had significant homology to genes of known function, of which 59% appeared to have roles in cellular metabolism and development, 24% in abiotic/biotic stress responses, 3% involved in transcription and signal transduction responses. Two putative resistance genes and a transcription factor were identified among the up regulated sequences. The expression of several candidate genes including a lipase, two non-specific lipid transfer proteins (ns-LTPs), and several wheat pathogenesis-related (PR)-proteins, was evaluated following 4 to 32 days post-inoculation in compatible and incompatible interactions. Results confirmed the higher overall expression of these genes in resistant BW553 compared to susceptible Neepawa, and the differential up-regulation of wheat lipase, chitinase and PR-1 proteins in the expression of the incompatible interaction.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.30-36
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• 2016

Brassinosteroids (BRs) are essential plant steroid hormones required for cell elongation, plant growth, development and abiotic and biotic stress tolerance. BRs are recognized by BRI1 receptor kinase that is localized in the plasma membrane, and the BRI1 protein will eventually autophosphorylate in the intracellular domain and transphosphorylate BAK1, which is a co-receptor in Arabidopsis thaliana. However, little is known of the role OsBRI1 receptor kinase plays in Oryza sativa, monocotyledonous plants, compared to that in Arabidopsis thaliana, dicotyledonous plants. As such, we have studied OsBRI1 receptor kinase in vitro and in vivo with recombinant protein and transgenic plants, whose phenotypes were also investigated. A OsBRI1 cytoplasmic domain (CD) recombinant protein was induced in BL21 (DE3) E.coli cells with IPTG, and purified to obtain OsBRI1 recombinant protein. Based on Western blot analysis with phospho-specific pTyr and pThr antibodies, OsBRI1 recombinant protein and OsBRI1-Flag protein were phosphorylated on Threonine residue(s), however, not on Tyrosine residue(s), both in vitro and in vivo. This is particularly intriguing as AtBRI1 protein was phosphorylated on both Ser/Thr and Tyr residues. Also, the OsBRI1 full-length gene was expressed in, and rescued, bri1-5 mutants, such as is seen in normal wild-type plants where AtBRI1-Flag rescues bri1-5 mutant plants. Root growth in seedlings decreased in Ws2, AtBRI1, and 3 independent OsBRI1 transgenic seedlings and had an almost complete lack of response to brassinolide in the bri1-5 mutant. In conclusion, OsBRI1, an orthologous gene of AtBRI1, can mediate normal BR signaling for plant growth and development in Arabidopsis thaliana.

• The Plant Pathology Journal
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• v.32 no.4
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• pp.300-310
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• 2016

Pathogen infection in plants induces complex responses ranging from gene expression to metabolic processes in infected plants. In spite of many studies on biotic stress-related changes in host plants, little is known about the metabolic and phenotypic responses of the host plants to Pseudomonas cichorii infection based on image-based analysis. To investigate alterations in tomato plants according to disease severity, we inoculated plants with different cell densities of P. cichorii using dipping and syringe infiltration methods. High-dose inocula (${\geq}10^6cfu/ml$) induced evident necrotic lesions within one day that corresponded to bacterial growth in the infected tissues. Among the chlorophyll fluorescence parameters analyzed, changes in quantum yield of PSII (${\Phi}PSII$) and non-photochemical quenching (NPQ) preceded the appearance of visible symptoms, but maximum quantum efficiency of PSII ($F_v/F_m$) was altered well after symptom development. Visible/near infrared and chlorophyll fluorescence hyperspectral images detected changes before symptom appearance at low-density inoculation. The results of this study indicate that the P. cichorii infection severity can be detected by chlorophyll fluorescence assay and hyperspectral images prior to the onset of visible symptoms, indicating the feasibility of early detection of diseases. However, to detect disease development by hyperspectral imaging, more detailed protocols and analyses are necessary. Taken together, change in chlorophyll fluorescence is a good parameter for early detection of P. cichorii infection in tomato plants. In addition, image-based visualization of infection severity before visual damage appearance will contribute to effective management of plant diseases.