• Korean Journal of Environmental Biology
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• v.26 no.1
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• pp.42-46
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• 2008

The community size of culturable heterotrophic bacteria and community level physiological profiles (CLPP) in the rhizosphere of Brassica rapa subsp. pekinensis (Chinese cabbage) were analyzed in two different sites. The average community size of culturable heterotrophic bacteria ranged between $2.65\times10^6CFU\;g^{-1}$ soil (Suwon) and $3.75\times10^6CFU\;g^{-1}$ soil (Yesan), whereas those of bulk soils ranged between $2.45\times10^6CFU\;g^{-1}$ soil (Suwon) and $2.97\times10^6CFU\;g^{-1}$ soil (Yesan). The average functional richness of Suwon rhizoshpere was 90.8, whereas that of Yesan rhizosphere was 154.1. High level of correlation was found between the community size and functional richness. The most actively utilized substrates in both rhizospheres were adonitol, L-asparagine, D-gluconic acid, L-glutamic acid and D-galacturonic acid. Clear differences were seen in the utilization patterns between the two sites. Differences were also observed for the patterns of bulk soils between the two sites, although D-raffinose and D-mannose were found as the commonly utilized substrates.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.329-335
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• 2021

Chinese cabbage fields have been damaged by cyst nematodes in highland of Gangwon province in Korea since the year 2011, and clover cyst nematode (CCN) is one of the most problematic cyst nematodes in the crop. To investigate the plant resources for breeding new Chinese cabbage cultivar, which is resistant to CCN, screening for resistance of fifty-seven Brassicaceae plant resources to CCN was conducted. Among the plant resources, fifty-four plant resources (Brassica rapa subsp. pekinensis, B. rapa, Brassica sp., B. juncea, B. carinata, B. rapa subsp. nipposinica, B. rapa subsp. narinosa, B. rapa var. perviridis, B. rapa var. perviridis, B. napus var. napobrassica, and Eruca sativa) were very susceptible to CCN and the number of females on roots was more than 300. Two plant resources (B. carinata and B. tournefortii) with more than 100 females on roots were susceptible to CCN. However, African mustard (B. tournefortii, Korean Genebank accession no. IT218058) was resistant to CCN because of the small number of females (4±1.8) on roots. This study showed that African mustard (IT218058) was valuable as a breeding material for Chinese cabbage, which is resistant to CCN.

• Molecules and Cells
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• v.28 no.5
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• pp.479-487
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• 2009

Glutathione reductase (GR) is an enzyme that recycles a key cellular antioxidant molecule glutathione (GSH) from its oxidized form (GSSG) thus maintaining cellular redox homeostasis. A recombinant plasmid to overexpress a GR of Brassica rapa subsp. pekinensis (BrGR) in E. coli BL21 (DE3) was constructed using an expression vector pKM260. Expression of the introduced gene was confirmed by semi-quantitative RT-PCR, immunoblotting and enzyme assays. Purification of the BrGR protein was performed by IMAC method and indicated that the BrGR was a dimmer. The BrGR required NADPH as a cofactor and specific activity was approximately 458 U. The BrGR-expressing E. coli cells showed increased GR activity and tolerance to $H_2O_2$, menadione, and heavy metal ($CdCl_2$, $ZnCl_2$ and $AlCl_2$)-mediated growth inhibition. The ectopic expression of BrGR provoked the co-regulation of a variety of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase. Consequently, the transformed cells showed decreased hydroperoxide levels when exposed to stressful conditions. A proteomic analysis demonstrated the higher level of induction of proteins involved in glycolysis, detoxification/oxidative stress response, protein folding, transport/binding proteins, cell envelope/porins, and protein translation and modification when exposed to $H_2O_2$ stress. Taken together, these results indicate that the plant GR protein is functional in a cooperative way in the E. coli system to protect cells against oxidative stress.

• Mycobiology
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• v.46 no.2
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• pp.172-176
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• 2018

A new species belonging to the genus Alternaria was isolated from the necrotic leaf spots of Brassica rapa subsp. pekinensis in Yuseong district, Daejeon, Korea. It is an occasional isolate, not an etiological agent, which is morphologically similar to A. broccoli-italicae, but differs in conidial size and conidiophore shape. Phylogenetic analysis using the sequence datasets of the internal transcribed spacer (ITS) region of the rDNA, glyceraldehyde-3-phosphate dehydrogenase (gpd), and plasma membrane ATPase genes showed that it is distantly related to A. broccoli-italicae and closely related to Alternaria species in the section Pseudoalternaria, which belonged to a clade basal to the section Infectoriae. Morphologically, the species is unique because it produces solitary conidia or conidial chains (two units), unlike the four members in the section Pseudoalternaria that produce conidia as short branched chains. It exhibits weak pathogenicity in the host plant. This report includes the description and illustration of A. brassicifolii as a new species.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.165-169
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• 2017

We organized the scientific names of Chinese cabbage according to the International Code of Nomenclature for algae, fungi, and plants (ICN) and the International Code of Nomenclature for Cultivated Plants (ICNCP). We found that the subspecies name 'Brassica rapa subsp. pekinensis (Lour.) Rupr.' was suitable as the scientific name for Chinese cabbage, and we classified B. rapa var. glabra Regel. as its synonym. In addition, B. petsai Bailey is an 'unrecorded name'   not found in the original description, and therefore is not suitable for use. We conclude that all names based on this name are 'invalid names', and should not be used.

• Research in Plant Disease
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• v.29 no.1
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• pp.72-78
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• 2023

In September 2021, gray-to-brown discoloration and expanding water-soaked lesions were observed on the outer and inner layers and the core of kimchi cabbage (Brassica rapa subsp. pekinensis) in fields located in Samcheok, Gangwondo, Korea. A bacterial strain designated as KNUB-02-21 was isolated from infected cabbage samples. Phylogenetic analysis based on the sequences of the 16S rRNA region and the dnaX, leuS, and recA genes confirmed that the strain was affiliated with Pectobacterium versatile. Additionally, the biochemical and morphological profiles of the isolate were similar to those of P. versatile. Based on these results, the isolate was identified as a novel strain of P. versatile. Healthy kimchi cabbage slices developed soft rot upon inoculation with P. versatile KNUB-02-21 and exhibited symptoms similar to those observed in the diseased plants in fields. The re-isolated strains were similar to those of P. versatile. Prior to our study, P. versatile as the causative pathogen of kimchi cabbage soft rot had not been reported in Korea.

• Journal of Environmental Science International
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• v.33 no.1
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• pp.27-41
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• 2024

In this study, we evaluated productivity, soil physiochemical properties, and soil microbial characteristics in Kimchi cabbage(Brassica rapa subsp. pekinensis) cultivation within a highland environment during summer. Specifically, we examined the effect of different cropping systems, namely monoculture and rotation with soybean, over an 8-year cropping period. The results of our investigation revealed that significant differences were absent in terms of yield and soil physiochemical properties between the two cropping systems. However, microbial characteristics exhibited distinctive patterns. Bacterial diversity was significantly higher in the rotation system that in the monoculture, whereas fungal diversity demonstrated a preference for rotation although the result was not significant. Our findings identified the presence of Bradyrhizobium stylosanthis, a nitrogen-fixation symbiont, as an indicator ASV (amplicon sequence variant) in the rotation system, where it displayed significantly higher abundances. These observations suggest a potential positive effect of the rotation system on nitrogen fixation. Notably, throughout the cultivation period, both cropping systems did not exhibit critical disease incidences. However, Fusarium oxysporum, a well-known pathogen responsible for inducing fusarium wilt disease in Kimchi cabbage, was detected with significantly higher abundance in the monoculture system. This finding raises concerns about the potential risk associated with Kimchi cabbage cultivation in a long-term monoculture system.

• Animal cells and systems
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• v.9 no.4
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• pp.239-244
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• 2005

A cDNA clone for a wound- and pathogen-induced gene in Chinese cabbage (Brassica rapa subsp. pekinensis) was isolated and characterized. The cabbage gene, designated BrPR4, encodes a pathogenesis-related protein 4 (PR4) of 140 amino acids. The BrPR4 protein shows high similarity with wound-inducible antifungal proteins of tobacco, potato, barley, and wheat. The BrPR4 gene is locally induced by a nonhost pathogen, Pseudomonas syringae pv. tomato, that elicits a hypersensitive response in Chinese cabbage. Treatment of the cabbage leaves with benzothiadiazole (BTH), methyl jasmonate or ethephon showed that the BrPR4 gene expression is strongly induced by ethylene, but not by methyl jasmonate or BTH. The BrPR4 gene is also activated by wounding. Interestingly, however, the wound-inducible BrPR4 gene expression is repressed by salicylic acid or BTH, suggesting that there is cross-talk between salicylate-dependent and -independent signaling pathways.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.136-139
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• 1994

Turnip mosaic virus (TuMV) was isolated from Rorippa islandica showing mild mosaic symptom in growing field of Chinese cabbage and radish. Identification of the virus was based on host range, transmission by aphids, electron micrograph, serological reaction and hybridization detection. The virus systemically infected on Chenopodium quinoa, Nicotiana clevelandii, N. glutinosa, Brassica rapa, B. campestris subsp. pekinensis and Raphanus sativus, whereas showed local infection on C. amaranticolor, Gomphrena globosa and Tetragonia tetragonoides. The virus was transmitted by aphid (Myzus persicae). The virus particle was filamentous with 720$\times$12 nm in length, and reacted positively with an antiserum of TuMV in agar gel double duffusion test. In slot-blot hybridization using the digoxigenin(DIG)-labeled RNA probe, TuMV-RNA could be detected in sap of R. islandica infected with the virus. This is the first report of a natural infection of that virus on R. islandica.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.587-594
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• 2020

In this study, we analyzed glucosinolates and their metabolites in the inner and outer parts of napa cabbage (NC; Brassica rapa subsp. pekinensis) and napa cabbage kimchi (NKC) using UPLC-ESI-MS/MS. In the extracts from NC and NKC, glucobrassicanapin (m/z 386), glucoalyssin (m/z 450), glucobrassicin (m/z 447), 4-methoxyglucobrassicin (m/z 477), and neoglucobrassicin (m/z 477) were detected using the MS scan mode ([M-H]-), and gluconapin (m/z 372→97), progoitrin (m/z 388→97), glucoiberin (m/z 422→97), 4-methoxyglucobrassicin (m/z 477→97), and neoglucobrassicin (m/z 477→447) were detected using the MS/MS MRM mode ([M-H]-). Ascorbigen (m/z 306→130) and indole-3-carboxaldehyde (I3A; m/z 146→118), which were metabolites of glucobrassicins, were detected using the MS/MS MRM ([M+H]+) mode. The peak intensities of ascorbigen in the extract from the inner and outer parts of NC were significantly higher than those of the NKC extract (p<0.05); however, there was no significant difference in I3A peak intensity between the NC and NKC extracts.