• Journal of Plant Biology
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• v.26 no.2
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• pp.91-99
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• 1983

The formation of chlorophyll-protein complexes (CP-complexes) during the greening of rape cotyledons (Brassica napus cv. Yongdang) was investigated by the SDS-polyacrylamide gel electrophoresis. The total chlorophyll content and Chl a/b ratio were also determined. In addition, the effects of dark treatment on the CP-complex patterns during greening have been examined with respect to their photosynthetic electron transport activity. Greening has brought about the increasein total chlorophyll content and the decrease in Chl a/b ratio, but there have been no changes in Chl a/b ratio after 24 hrs of greening. The light-harvesting chlorophyll a/b-protein complex (LHCP-complex0 was predominant during the initial greening period. Thereafter, the amout of chlorophyll a-protein complex (CP I-complex) was gradually increased. Twenty-four-hr dark treatment immediately after illumination for 6 hrs and 12 hrs resulted in the increase of the Chl a/b ration and the CP I complex, otherwise the decrease of the LHCP-complex. The LHCP/CP I ratio was gradually decreased with further greening, and appeared no change after 48 hrs illumination. The investigation of the photosynthetic electron transport activity indicated that photosystem (PS) II activity (H2Olongrightarrowp-PD*＋FeCy**) did not change, but the activity of PS I was increased suddenly due to the dark treatment. The data suggests that the increase of CP I-complex may result in that of P-700, that is, the increase of PS I activity.

• Plant Biotechnology Reports
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• v.4 no.4
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• pp.243-251
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• 2010

Nitric oxide (NO) has been shown to be involved in diverse physiological processes in microbes, animals and plants. In this study, the involvement of NO in the development and possible roles in oxidative stress protection of Chinese cabbage (Brassica rapa subsp. pekinensis cv. Samrack-ulgari) seedlings were investigated. Exogenous application of sodium nitroprusside (SNP) retarded root elongation, while increasing lateral root formation of Chinese cabbage. Plants showed no signs of external stress due to SNP application in true leaves. Cotyledons of 3-week-old Chinese cabbage plants were found to be highly sensitive to SNP application. Treated cotyledons displayed rapid tissue collapse and associated cell death. Although SNP application reduced root growth under normal growth conditions, it also enhanced methyl viologen (MV)-mediated oxidative stress tolerance. Analysis of SNP application to Chinese cabbage leaf disks, revealed SNP-induced tolerance against oxidative stresses by MV and $H_2O_2$, and evidence includes prevention of chlorophyll loss, superoxide anion (${O_2}^-$) accumulation and lipid peroxidation. This report supports a role for nitric oxide in modulating early seedling development, programmed cell death and stress tolerance in Chinese cabbage.

• Korean Journal Plant Pathology
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• v.1 no.3
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• pp.173-177
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• 1985

The objective of the study is to determine differences between cucurbits in the pathogenicity of Didymella bryoniae isolated from the naturally infected seeds of cucumber and pumpkin. Primary seedling infection of cucumber(Cucumis sativus L.), oriental melon(Cucumis melo var. makuwa Makino), pumpkin(Cucurbita pepo L.) and watermelon (Citrullus vulgaris Shrad.) occurred on the radicle, hypocotyl and cotyledons and symptoms on each crop were very similar. Infection of the radicle generally caused pre-emergence rot, while infection on the hypocotyl and cotyledons provided further inoculum for infection of the first true leaves and the stem. In cross inoculation tests, all isolates of D. bryoniae could infect cucumber, oriental melon, pumpkin and watermelon at different growth stages and there were not much differences in pathogenicity or susceptibility between isolates of the pathogen and crops tested. The susceptibility of cucumber and pumpkin was markedly influenced by prevailing humid conditions.

• Journal of Photoscience
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• v.5 no.3
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• pp.131-135
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• 1998

Using differential display reverse transcription technique, the present study attempted to isolate and characterize genes specifically expressed in cotyledons of Pharbitis nil Choisy cv. Violet during floral induction. A total of 107 bands specific to the inductive condition were initially obtained with 80 primer sets of 20 different arbitrary primers combined with 4 kinds of T12MN. In northern blot analysis with reamplified cDNAs as probes, three cDNAs were detected to be expressed specificcally in the induced cotyledon tissues, and designated PnFL-1, PnFL-2 and PnFL-3 , the size of which were 228 bp, 317 bp and 272 bp, respectively. A search for sequences similar to the decuced amino acid sequences was conducted using GenBank and EMBL database ; seequence encoded by PnFL-1 had 29% identity with the clone of Arabidopsis thaliana similiar to reverse trascriptase (Genbank Acc. N0.3047086), PnFL-2 shared 50% identity with hydroxiyproline-rich glycoprotein of Glycine max(GenBank Acc. No.347455), and PnFL-3 had 46% identity with TAMU 4. Thaliana genomic clone T23E16 (GenBank Acc. No.B67574). None of them was known gene in the plant system up to date, implying that the fragments may comprise parts of genes which are associated with the floral induction in Pharbitis nil.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.30-39
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• 1998

Carrot seedling emgryos showing variations in cotyledon number were selected and anatomical comparisons of the embryo vascular systems were performed between the variants and normal two cotyledonary (5) embryos from 800 seedings germinated . Externally, all of the four and six cotyledonary embryos had two cotyledonary petioles. Each of the cotyledonary petioles divided into two or three on the upper part fo the petiole which result in four and six cotyledons, respectively. However, the embryos had three different cotyledonary petioles in the three cotyledonary embryos. On the basis of the pattern of vascular system, the four and six cotyledonary embryos had the same basic vascular system as fnormal two cotyledonary embryos, Therefore the cotyledon number abnormality could result from the branching split of the abnormally thickened upper part of the cotyledonary petiole. However, the three cotyledonaryembryos had a different vascular system from the normla two cotyledonary embryos. They could be regarded as different varieties form the two cotyledon embryos. All embryos observed had short cylindrical plumule sheath which formed by the fusion of the cotyledon bases. The presence of plumule sheath strontgly implied that the initiation of the cotyledons was not from the two localized primordia but from the circular proimordiu formed at the blobular stageof embryo, and it is not consistent with current views of cotyledon initiation. On the formation of the primary vascular system of carrot seedlings, it is suggested that the primary vascular system of the plumule was formed independently from that of the root-hypocotyle-cotyledon system.

• Plant Breeding and Biotechnology
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• v.2 no.3
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• pp.289-300
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• 2014

A tissue-specific and developmentally expressed gene was isolated from Chinese cabbage (Brassica rapa L. ssp. pekinensis), designated BrREF (B. rapa Rubber elongation factor). BrREF transcripts were expressed at high levels in seedlings and at low levels in flower buds and roots. To study the activity of this promoter, the 2.2 kb upstream sequence of BrREF gene was fused to a β-glucuronidase (GUS) reporter gene and was introduced into Arabidopsis thaliana and B. napus by Agrobacterium-mediated transformation. Strong expression of GUS driven by the BrREF promoter was detected in the cotyledons and hypocotyls of transgenic plant seedlings, but GUS expression was weak in roots, excluding the root tips. GUS expression in the cotyledons and hypocotyls decreased dramatically as the seedlings matured and was not detected in the tissues of mature plants. During floral development, GUS expression was observed in immature anthers. These findings suggest that the BrREF promoter can modulate the tissue-specific and developmental expression of gene at the early stages of growth and development.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.spc1
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• pp.25-45
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• 1996

Soyfoods have potential roles in the prevention and treatment of chronic diseases, most notably cancer, osteoporosis, and heart disease. There is evidence that carcinogenesis are supressed by isolated soybean derived products in vivo such as a protease inhibitor, phytic acid, saponins and isoflavones. It is believed that supplementation of human diets with soybean products markedly reduces human cancer mortality rates. Especially, recent papers recognize the potential benefit of soybean isoflavone components for reducing the risk of various cancers. Isoflavones exhibit a multitude of medicinal effects that influence cell growth and regulation, which may have potential value in the prevention and treatment of cancer. In addition to potential biological effects, soybean isoflavones have the important physiological functions such as the induction of Bradyrizobium japonicum nod genes and the responses of soybean tissues to infection by Phytophthora megasperma as well as biochemical activities such as antifungal and antibacterial actions. Genistin, daidzin, glycitin and their aglycone (genistein, daidzein, glycitein) are the principal isoflavones found in soybean. Malonyl and acetyl forms have also been detected but they are thermally unstable and are usually transformed during the processing in glucoside form. Most soy products, with the exception of soy sauce, alcohol-extracted soy protein concentrate, and soy protein isolate, have total isoflavone concentrations similar to those in the whole soybean. Soybean-containing diets inhibit mammary tumorigenesis in animal models of breast cancer, therefore, it is possible that dietary isoflavones are an important factor accounting for the lower incidence and mortality from breast cancer. Of the total soybean seed isoflavones, $80\~90\%$ were located in cotyledons, with the remainder in the hypocotyls. The hypocotyls had a higher concentrations of isoflavones on a weight basis compared with cotyledons. Isoflavone contents were influenced by genetics, crop years, and growth locations. The effect of crop year had a greater impact on the isoflavone contents than that of location. The climate condition might be the attribution factor to variation in isoflavone contents. Also, while the isoflavone content of cotyledons exhibited large variations in response to high temperature during seed development, hypocotyls showed high concentration in isoflavone content. So, it is concluded that one of the factors affecting isoflavone content in soybean seeds is temperature during seed development. High temperature, especially in maturity stage, causes lower isoflavone content in soybean seed. It is also suggested that there may exist a different mechanism to maintain isoflavone contents between cotyledon and seed hypocotyls. In a conclusion, soy foods may be able to have a significant beneficial impact on public health.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.267-271
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• 1995

To improve regeneration efficiency of Brassica campestris ssp. pekinensis (chinese cabbage) in vitro, the effect of ehtylene inhibitors [AgNO$_3$ and silver thiosulfate (STS)] and optimal age of explantse were investigated. On the effect of ethylene inhibitors either 100 $\mu$M of AgNO$_3$ or 5 $\mu$M of STS enhanced shoot regeneration from cotyledons when it was added in basal shoot induction media(MS salts, B5 vitamine, sucrose 2%, BA 2.0mg/L, NAA 1.0mg/L). But at higher concentrations, AgNO$_3$ induced abnormal shoots, and STS greatly reduced regeneration frequency. On the other hand, the maximum regeneration rate was obtained from the cotyledons taken from 3-day old seedlings. However there was no distinctive effect among the containers used for cultivation. The most optimal condition of root induction was a minimal Murashige and Skoog media containing 0.1 mg/L NAA. In order to induce bolting and flowering from in vitro regenerated chinese cabbage, the plant were healed at 4$^{\circ}C$ for weeks in a cold chamber. When they were planted in pots, the plane produced phenotipically normal flowers and seeds. The overall results suggest that ethylene inhibitors promote regeneration of shoot from cotyledons of chinese cabbage without alleviating fertility.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.179-184
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• 2020

Embryogenic calli from Codonopsis lanceolata L. were cultured in MS liquid media and supplemented with various concentrations of primary carbon sources to study the effects of carbohydrates and osmoticum on somatic embryogenesis and somatic embryo morphology. Sucrose, glucose, and a combination of 3% sucrose and various concentrations of sorbitol or mannitol as osmoticum were used as carbon supplements. The maximum number of somatic embryos per flask was greater in media exclusively supplemented with 3% sucrose (128.29) than exclusively glucose-supplemented media (47.67) and either supplement combination of 3% sucrose and osmoticum (95.67 with mannitol and 114.00 with sorbitol). The number of somatic embryos gradually decreased in media with increasing concentrations of combined osmoticum supplement. Decreases also occurred in the highest concentrations of sucrose- and glucose-supplemented media. The total frequency of somatic embryos with two cotyledons was slightly higher in medium with 3% + mannitol (24.09%) compared with exclusively sucrose (21.52%), glucose (21.22%), or 3% sucrose + sorbitol (22.13%). As concentrations of sucrose and glucose increased, the occurrence of two cotyledons and trumpet cotyledons gradually decreased and the occurrence of polycotyledon and globular stage embryos increased. Furthermore, as concentrations of 3% sucrose and osmoticum increased, the occurrence of trumpet cotyledon and globular stage embryos increased and the occurrence of polycotyledon gradually decreased. These results demonstrated that the somatic embryogenesis and occurrence of cotyledon morphology were influenced by the concentration of carbohydrates and combinations of 3% sucrose and osmoticum supplements.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.891-898
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• 2008

The physicochemical and sensory characteristics of commercial film-packed soybean sprouts from domestic cultivars were investigated. The hardness of the cotyledons was higher than that of the hypocotyls in fresh and cooked soybean sprouts (Kongnamulmuchim). Furthermore, the color determination showed that the hypocotyls and cotyledons of the soybean sprouts had a light green color that was not eliminated by cooking. The acceptability of fresh soybean sprouts was negatively correlated with a beany odor, beany taste, and grassy taste, but positively correlated with a nutty odor, nutty taste, and sweet taste. In addition, the acceptability of boiled soybean sprouts was negatively correlated with a beany and grassy taste, and positively correlated with a nutty odor and taste. Furthermore, the acceptability of cooked soybean sprouts was negatively correlated with a beany odor, beany taste, grassy odor, and grassy taste, while it was positively correlated with a nutty odor and taste. Finally, the lipoxygenase activity of the cotyledons was higher than that of the hypocotyls in fresh and boiled soybean sprouts.