• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.132-137
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• 2016

The genus Cypripedium, known as lady's slipper orchid, has been considered to have a considerable marketability as a potted and garden plant with beautiful flowers; however, this species is becoming endangered and, in some places extinct, due to habitat destruction and illegal collections. As such, an optimized artificial propagation system is necessary for its conservation and horticultural cultivation. For the establishment of the in vitro proliferation of the endangered Cypripedium macranthos Sw., native to Korea, the effects of medium strength and sucrose concentrations on germination, protocorm formation and seedling growth were investigated through asymbiotic seed culture. The highest germination rate and protocorm formation rate were obtained with a 1/4 MS medium; higher MS medium strengths did not generate the favorable conditions required for germination and protocorm growth. The overall growth characteristics of roots and buds developed from protocorms were best in cultures of 1/4 MS medium. On this medium containing $10g{\cdot}L^{-1}$ sucrose, both the germination rate and protocorm formation rate increased significantly. The general growth properties of seedlings developed on the medium with $10g{\cdot}L^{-1}$ sucrose were best, showing the highest bud formation rate and root number. Our results demonstrate that the 1/4 MS medium, supplemented with $10g{\cdot}L^{-1}$ sucrose, could improve in vitro germination, and facilitate the growth of seedlings developed from the protocorms of C. macranthos Sw.

• The Plant Pathology Journal
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• v.30 no.3
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• pp.323-329
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• 2014

Two cultivars Buram-3-ho (susceptible) and CR-Hagwang (moderate resistant) of kimchi cabbage seedlings showed differential defense responses to anthracnose (Colletotrichum higginsianum), black spot (Alternaria brassicicola) and black rot (Xanthomonas campestris pv. campestris, Xcc) diseases in our previous study. Defense-related hormones salicylic acid (SA), jasmonic acid (JA) and ethylene led to different transcriptional regulation of pathogenesis-related (PR) gene expression in both cultivars. In this study, exogenous application of SA suppressed basal defenses to C. higginsianum in the 1st leaves of the susceptible cultivar and cultivar resistance of the 2nd leaves of the resistant cultivar. SA also enhanced susceptibility of the susceptible cultivar to A. brassicicola. By contrast, SA elevated disease resistance to Xcc in the resistant cultivar, but not in the susceptible cultivar. Methyl jasmonate (MJ) treatment did not affect the disease resistance to C. higginsianum and Xcc in either cultivar, but it compromised the disease resistance to A. brassicicola in the resistant cultivar. Treatment with 1-aminocyclopropane-1-carboxylic acid (ACC) ethylene precursor did not change resistance of the either cultivar to C. higginsianum and Xcc. Effect of ACC pretreatment on the resistance to A. brassicicola was not distinguished between susceptible and resistant cultivars, because cultivar resistance of the resistant cultivar was lost by prolonged moist dark conditions. Taken together, exogenously applied SA, JA and ethylene altered defense signaling crosstalk to three diseases of anthracnose, black spot and black rot in a cultivar-dependent manner.

• Research in Plant Disease
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• v.15 no.2
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• pp.77-82
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• 2009

The roots of grapevine in the field in which the crown gall was occurred severely in Chungbuk province were collected and Agrobacterium spp. were isolated from the roots using the selective media. The selected 13 isolates were identified as A. tumefaciens with fatty acid analysis using MIDI system, nucleotide sequence of 16S rDNA, biochemical characteristics, and PCR with the species-specific primers. A. vitis, a pathogen of crown gall disease of grapevine was not isolated from the roots. All of the isolates did not show pathogenicity on the tomato seedlings and the stem and root of grapevine. Eric-PCR showed that DNA band patterns of the root isolates were a little more similar to A. tumefaciens than A. vitis. However, overall similarity between the root isolates and the pathogenic strains of A. tumefaciens and A. vitis was low by rep-PCR. These results suggest that a pathogen causing crown gall in grapevine in Chungbuk province may transmitted through the seedlings rather than via soil or roots.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.223-226
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• 2008

Seedlings of two rice cultivars i.e. cv. Daesanbyeo and cv. Dongjinbyeo were analyzed for growth and endogenous gibberellins (GAs) in response to nitrogen nutrition applied in the forms of $KNO_3$, $(NH_4)_2SO_4$ and $NH_4NO_3$. All the growth parameters showed an increase in N applied treatments and their magnitudes of increase were different depending on different nitrogen fertilizer forms. The endogenous GAs contents were increased with N application but differentially affected by various N-forms in both rice cultivars. In cv. Daesanbyeo, maximum amount of bioactive $GA_1$ was recorded for $(NH_4)_2SO_4$, while maximum amount of bioactive $GA_1$ in cv. Dongjinbyeo was observed in $NH_4NO_3$ applied treatments. In both rice cultivars, $KNO_3$ applied rice plants contained least $GA_1$ contents. Also, $GA_{19}$ was the most abundant GA found in rice seedlings whereas $GA_4$ was absent at seedling stage. Our study indicated that different rice cultivars showed different responses for the same fertilizer depending upon the response potential of each cultivar and the pertinent physiological responses to changes of endogenous GAs in rice cultivars, which were comparatively lesser in magnitude.

• Molecules and Cells
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• v.19 no.1
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• pp.67-73
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• 2005

Isoflavones are synthesized by isoflavone synthases via the phenylpropanoid pathway in legumes. We have cloned two isoflavone synthase genes, IFS1 and IFS2, from a total of 18 soybean cultivars. The amino acid residues of the proteins that differed between cultivars were dispersed over the entire coding region. However, amino acid sequence variation did not occur in conserved domains such as the ERR triad region, except that one conserved amino acid was changed in the IFS2 protein of the GS12 cultivar ($R_{374}G$) and the IFS1 proteins of the 99M06 and Soja99s65 cultivars ($A_{109}T$, $F_{105}I$). In three cultivars (99M06, 99M116, and Simheukpi), most of amino acid changes were such that the difference between the amino acid sequences of IFS1 and IFS2 was reduced. The expression profiles of three enzymes that convert naringenin to the isoflavone, genistein, chalcone isomerase (CHI), isoflavone synthase (IFS) and flavanone 3-hydroxylase (F3H) were examined. In general, IFS mRNA was more abundant in etiolated seedlings than mature plants whereas the levels of CHI and F3H mRNAs were similar in the two stages. During seed development, IFS was expressed a little later than CHI and F3H but expression of these three genes was barely detectable, if at all, during later seed hardening. In addition, we found that the levels of CHI, F3H, and IFS mRNAs were under circadian control. We also showed that IFS was induced by wounding and by application of methyl jasmonate to etiolated soybean seedlings.

• Korean Journal of Weed Science
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• v.14 no.2
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• pp.101-106
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• 1994

Factors affecting phytotoxicity of dithiopyr in rice such as transplanting depth, seedling age, soil texure were examined and mechanism of phytotoxicity in rice was also determined by absorption study of $^{14}C$-dithiopyr in rice seedlings under above conditions. Rice injury was occurred in shallow transplanting depth, young rice seedlings and sandy soil conditions. Higher amount of dithiopyr was absorbed in rice at shallow transplanting depth and sandy soil conditions which may related to phytotoxicity of dithiopyr.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.390-393
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• 1997

Hormetic effects of low dose radiation were analyzed in terms of growth stimulation in radish and three cultivars of chinese cabbage. Seeds irradiated with ${\gamma}$ radiation were planted in the green house and in the experimental field. Though it varied with cultivars of tested plants, hormetic effect of low dose ${\gamma}$ radiation on an early stage of growth were shown especially in germination rates and elongation of seedlings. The height of seedlings increased in 0.2 Gy irradiated group of Seolim cultivar and radish, in 1 Gy irradiated group of Konaenggi cultivar and in 4 Gy irradiated group of Ducksung cultivar, respectively, In case of plants grown in the experimental field, prominent were the height increase of radish and Seolim cultivar in 1 Gy irradiated group and the fresh weight increase of both radish and cabbage in 4 Gy irradiated group.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.47-51
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• 1996

This study was carried out to investigate the relation between bolting rate and root yield of Angelica gigas for 3 years from 1992 to 1994. Plant height at early growth stage and bolting rate showed linear regression as y=-8.502+0.5449x. Root yield was highest at the field with 11% bolting. Root yield of Angelica gigas in relation to seedling size was highest from medium and small seedlings with 10 to 15% bolting and from large seedlings with below 10% bolting.

• Molecules and Cells
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• v.28 no.5
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• pp.463-472
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• 2009

Although the possible cellular roles of several ubiquitin-specific proteases (UBPs) were identified in Arabidopsis, almost nothing is known about UBP homologs in rice, a monocot model plant. In this report, we searched the rice genome database (http://signal.salk.edu/cgi-bin/RiceGE) and identified 21 putative UBP family members (OsUBPs) in the rice genome. These OsUBP genes each contain a ubiquitin carboxyl-terminal hydrolase (UCH) domain with highly conserved Cys and His boxes and were subdivided into 9 groups based on their sequence identities and domain structures. RT-PCR analysis indicated that rice OsUBP genes are expressed at varying degrees in different rice tissues. We isolated a full-length cDNA clone for OsUBP6, which possesses not only a UCH domain, but also an N-terminal ubiquitin motif. Bacterially expressed OsUBP6 was capable of dismantling K48-linked tetra-ubiquitin chains in vitro. Quantitative real-time RT-PCR indicated that OsUBP6 is constitutively expressed in different tissues of rice plants. An in vivo targeting experiment showed that OsUBP6 is predominantly localized to the nucleus in onion epidermal cells. We also examined how knock-out of OsUBP6 affects developmental growth of rice plants. Although homozygous T3 osubp6 T-DNA insertion mutant seedlings displayed slower growth relative to wild type seedlings, mature mutant plants appeared to be normal. These results raise the possibility that loss of OsUBP6 is functionally compensated for by an as-yet unknown OsUBP homolog during later stages of development in rice plants.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.3
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• pp.231-236
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• 2017

Salt stress is one of the most limiting factors that reduce plant growth, development and yield. However, identification of salt-inducible genes is an initial step for understanding the adaptive response of plants to salt stress. In this study, we used an annealing control primer (ACP) based GeneFishing technique to identify differentially expressed genes (DEGs) in Italian ryegrass seedlings under salt stress. Ten-day-old seedlings were exposed to 100 mM NaCl for 6 h. Using 60 ACPs, a total 8 up-regulated genes were identified and sequenced. We identified several promising genes encoding alpha-glactosidase b, light harvesting chlorophyll a/b binding protein, metallothionein-like protein 3B-like, translation factor SUI, translation initiation factor eIF1, glyceraldehyde-3-phosphate dehydrogenase 2 and elongation factor 1-alpha. These genes were mostly involved in plant development, signaling, ROS detoxification and salt acclimation. However, this study provides new molecular information of several genes to understand the salt stress response. These genes would be useful for the enhancement of salt stress tolerance in plants.