• The Korean Journal of Ecology
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• v.23 no.2
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• pp.149-155
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• 2000

The allelopathic effects of Artemisia lavandulaefolia were studied using several test plants and microbes. Aqueous extracts and volatile compounds of A. lavandulaefolia inhibited seed germination, seedling and root growth of the test species such as Achyranthes japonica. Lactuca sativa, Artemisia princeps var. orientalis. Oenothera odorata, Plantago asiatica. Aster yomena, Elsholtzia ciliata, and Raphanus sativus var. hortensis for. acanthiformis. The root growth of test species was more affected than shoot growth by allelochemicals of A. lavandulaefolia. Essential oil of A. lavandulaefolia had antibacterial and antifungal effects. However, the antimicrobial activity of the essential oil was dependent upon the microbial species and concentrations. Callus growth of Oryza sativa, Brassica campestris subsp. napus var. pekinensis and Achyranthes japonica was sensitive by the essential oil of A. lavandulaefolia. Twenty three chemicals were identified from A. lavandulaefolia essential oil by gas chromatography. Primary allelochemicals among them were 1, 8-cineole, 1-$\alpha$-terpineol, $\alpha$-terpinene. camphor, 2-buten-1-ol and azulene. We concluded that aqueous extract and essential oil of A. lavandulaefolia were responsible for allelopathic effects.

• The Korean Journal of Ecology
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• v.23 no.6
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• pp.431-434
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• 2000

To examine the allelopathic potentials of Chrysanthemum boreale, aqueous extracts and essential oil of the plant were used in these experiments. Seed germination of the receptor species was inhibited by the aqueous extracts and the inhibitory effect was increased in proportion to the concentration of extracts. In contrast, seedling elongation showed varied results. Achyranthes japonica, Bidens bipinnata, Raphanus sativus var. hortensis for. acanthiformis, Plantago asiatica, Pimpinella brachycarpa and Lactuca sativa were inhibited by increasing concentration of the aqueous extract, while Brassica campestris subsp. napus var. pekinensis and Echinochloa crus-galli were stimulated by the extract. Dry weight was also inhibited proportionally by increasing concentration of the aqueous extract, while some species were stimulated by a lower concentration of the extract. The volatile substances of C. boreale did not affect the seed germination of receptor plants, but seedling elongation and dry weight of some species were inhibited dose-dependently. Root hair development of selected plants was inhibited along with the concentration of essential oil. The above mentioned results, therefore, confirmed that the natural substances from C. boreale had allelopathic potentials to other plants.

• BMB Reports
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• v.41 no.6
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• pp.472-478
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• 2008

Three Arabidopsis cDNAs, MAM1, CYP79F1, and CYP83A1, required for aliphatic glucosinolate biosynthesis were introduced into Chinese cabbage by Agrobacterium tumefaciens-mediated transformation. The transgenic lines overexpressing MAM1 or CYP83A1 showed wild-type phenotypes. However, all the lines overexpressing CYP79F1 displayed phenotypes different from wild type with respect to the stem thickness as well as leaf width and shape. Glucosinolate contents of the transgenic plants were compared with those of wild type. In the MAM1 line M1-1, accumulation of aliphatic glucosinolates gluconapin and glucobrassicanapin significantly increased. In the CYP83A1 line A1-1, all the aliphatic glucosinolate levels were increased, and the levels of gluconapin and glucobrassicanapin were elevated by 4.5 and 2 fold, respectively. The three CYP79F1 transgenic lines exhibited dissimilar glucosinolate profiles. The F1-1 line accumulated higher levels of gluconapoleiferin, glucobrassicin, and 4-methoxy glucobrassicin. However, F1-2 and F1-3 lines demonstrated a decrease in the levels of gluconapin and glucobrassicanapin and an increased level of 4-hydroxy glucobrassicin.

• 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.14 no.5
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• pp.433-439
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• 1998

The studies on the ecology of virus disease on Chinese cabbage (Brassica campestris subsp. pekinensis) cultivated in alpine area of Kangwon province during summer season to analyse its influence on damage and develope a prediction model were performed from 1993 to 1997. Virus disease on Chinese cabbage occurring in the alpine area showed various symptom types and among there, necrotic spots and dwarf were mainly detected. The disease was increased from early August and continued mid September in every year. The occurrence of virus disease was the highest in 1994 with 20.5%, and the number of aphid vectors were also the highest during the same period. The number of aphids in the alpine areas showed twice peaks every year. For the analysis of damage by virus infection, the infection and injured ratio of all treatments were more than 90% and 80%, respectively. The most important factor for the occurrence of virus disease on Chinese cabbage was temperature. Factors influencing the development of the viral disease in the alpine area were maximum temperature and number of aphid vectors.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.625-629
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• 1998

Turnip mosaic potyviruses (TuMV) were isolated from Rorippa indica and Armoracia lapathifolia showing mosaic symptoms in field. Identification of the TuMVs were carried out by host reactions of indicator plants, electron micrograph, serological properties and reverse transcription-poly-merase chain reaction (RT-PCR). Both viruses systemically infected Chenopodium quinoa, Nicotiana clevelandii, Brassica rapa, B. campestris subsp. pekinensis, B. juncea and Raphanus sativus, and developed local infection on inoculated leaves of C. quinoa, C. amaranticola, C. album, N. tabacum cv. Xanthi nc and Gomphrena grobosa. However, the viruses did not infect on N. glutinosa, Cucumis sativus and Vigna unguiculata. The filamentous particles, about 720 nm in length, and inclusion bodies were observed from the infected leaf tissues by dipping on electron microscopy. Crude sap of leaf infected with the viruses was reacted positively with an antiserum of TuMV in agar gel double diffusion. For detection of the viruses, RT-PCR was carried out with TuMV--specfic oligonucleotide primer. The RT-PCR products, a 1,092 bp DNA fragment, were obtained from naturally infected leaves of R. indica and A. lapathifolia. In inoculation test to seven cruciferous weeds with TuMV, infection occurred in Arabis glabra, Barbarea orthoceras, Capsella bursa-pastoris, Draba nomorosa var. hebecarpa, Rorippa cantoniensis and Thlaspi arvense.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.1034-1036
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• 2005

Chinese cabbage (Brassica campestris ssp. napus var. pekinensis Makino) seeds/seedlings were transformed via vacuum-infiltration with recombinant Agrobacterium tumefaciens LBA4404 cells. The agroinfiltration method was determined to be unsuccessful for Chinese cabbage transformation during the analysis of hepatitis B surface antigen expression by ELISA. However, treatment of sodium hypochlorite solution, prior to agroinfiltration, to pregerminated or germinating 1 day- or 2 days-old seeds was proven effectively to enhance transformation efficiency, suggesting that chemical wounding caused by sodium hypochlorite reaction might facilitate Agrobacterium infection and, therefore, transient gene expression in Chinese cabbage sprouts.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.91-99
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• 2014

The objective of this study is to identify cold-tolerance genes in Brassica rapa. In order to acheive this goal, we analyzed a KBGP-24K oligo chip data [BrEMD (B. rapa EST and Microarray Database)] using B. rapa ssp. pekinensis inbred line 'Chiifu' under cold stress condition ($4^{\circ}C$). Among 23,929 unigenes of B. rapa, 417 genes (1.7%) were primarily identified as cold responsive genes that were expressed over 5-fold higher than those of wild type control, and then a gene which has unknown function and has full length sequence was selected. It was named BrCSR (B. rapa Cold Stress Resistance). BrCSR was transformed using expression vector pSL101 to confirm whether BrCSR can enhance cold tolerance in tobacco plants. $T_1$ transgenic tobacco plants expressing BrCSR were selected by PCR and Southern hybridization analyses, and the function of BrCSR was characterized by expression level analysis and phenotype observation under cold stress condition. The expression level of BrCSR in transgenic tobacco plants increased up to about two folds in quantitative real-time RT-PCR assay and this was very similar to Northern blot hybridization analysis. Analysis of phenotypic characteristics clearly elucidated that transgenic tobaccos expressing BrCSR were more cold tolerant than wild type control under $4^{\circ}C$ treatment. Based on these results, we conclude that the over-expression of BrCSR might be closely related to the enhancement of cold tolerance.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.820-828
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• 2015

This study was carried out to determine the effects of vernalization, temperature, and soil water deficit (SD) on mesophyll cells, growth, and yield of Chinese cabbage (Brassica campestris L). The palisade parenchyma and spongy tissues of Chinese cabbage were observed under full irrigation and two weeks of SD treatment. These cells were severely collapsed by four weeks SD treatment. The SD treatment had the greatest influence on the growth of Chinese cabbage among the tested treatment factors (vernalization, temperature, and SD), growth significantly decreased by severe drought treatment (four weeks SD treatment). In addition, the relative growth rate, unit leaf rate, leaf area ratio, specific leaf area, and leaf weight ratio were significantly affected by SD treatment; however, other individual factors and their combined treatments did not influence the analyzed growth parameters. The yield under vernalization after high temperature and full irrigation treatments was 3,056 kg/10 a, which was the greatest among all the tested treatments, while four-week SD treatment significantly reduced the yield. Head formation of Chinese cabbage was not altered under SD treatment, and vernalization treatments did not induce bolting. Our results indicated that collapsing mesophyll cells and reduced growth and yield were induced by SD treatment. Thus we suggest that optimal irrigation system should be install to avoid or overcome crippling drought conditions in the open field.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.399-401
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• 2015

This study investigated the plant growth promoting activity of geraniol on Chinese cabbage (Brasscia campestris ssp. Pekinensis Rupr.), Pak Choi (Brassica rapa L.), Crown daisy (Chrysanthemum coronarium L.), Iceberg lettuce (Lactuca sativa L.) and Leaf perilla (Perilla frutescens Britt.). Geraniol at 0.5 to $10mg\;L^{-1}$ promoted radical growth of Chinese cabbage Pak Choi, Crown daisy, Iceberg lettuce and leaf perilla by >30%. In the pot experiments, geraniol treatment at $20mg\;L^{-1}$ by drenching increased up to 190% of the aerial part growth promotion. By comparison, foliar application showed 124% promoting activity only at $100mg\;L^{-1}$.