• Journal of Plant Biology
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• v.34 no.3
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• pp.185-190
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• 1991

Hypocotyl-derived callus cultures of Brassica pekinensis cv. Chungseng were grown on Murashige-Skoog medium containing NaCl, Na2SO4 and mannitol to clarify the effect of salts on callus growth, proline accumulation and water relations. Na2SO4 was more inhibitory than NaCl when survival rate, growth and fresh:dry weight ratios of established callus were measured. Fresh weight in 0.25% NaCl treatment was more than twice as increasable in comparison to the same concentration of Na2SO4 or control. Proline concentration was increased on either salt, attained at highest levels at the 5th subculture, and fluctuated as affected by both salts or mannitol. Concentrations of redeucing sugars were sharply increased after 2 or 3 times of subculture and decreased by increasing subculture. The water and osmotic potential in callus reached a maximum negative value after two weeks in culture, regardless of salt type and mannitol and tugor remained relatively constant on both salt and mannitol treatments.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.730-738
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• 2014

The objective of this study was to evaluate glucosinolate (GSL) profiles and variation of total and individual GSLs concentrations within seedling (0-14 days) and growth stages (0-15 weeks) of Korean Chinese cabbage (Brassica rapa L. ssp. pekinensis). Ten GSLs (progoitrin, glucoraphanin, glucoalyssin, gluconapin, glucobrassicanapin, 4-hydroxyglucobrassin, glucobrassicin, 4-methoxyglucobrassicin, neoglucobrassicin and gluconasturtiin) were identified from Korean Chinese cabbage. In general, total GSL content significantly decreased during seedling (from 92.89 to $35.26{\mu}mol{\cdot}g^{-1}$ DW) and g rowth stages ( from 74.11 to $1.97{\mu}mol{\cdot}g^{-1}$ DW). Gluconapin was the highest in seeds and in the germination period ($73.1{\mu}mol{\cdot}g^{-1}$ DW) and declined gradually from 73 to 15% during seedling stages. The level of the major aliphatic GSLs, gluconapin and progoitrin, tended to decrease sharply, whereas levels of indolic GSLs (4-methoxyglucobrassicin, glucobrassicin) and aromatic GSLs (gluconasturtiin) were found to increase generally at the beginning of growth stages.

• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.59-65
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• 2002

ADP-glucose pyrophosphorylase (AGPase) catalyzes the key regulatory step in starch biosynthesis. Two cDNA clones encoding AGPase subunits were isolated from the leaf cDNA library of Chinese cabbage (Brassica campestris L. spp. pekinensis). One was designated as BCAGPS for the small subunit and the other as BCAGPL for the large subunit. Both cDNAs have uninterrupted open reading frames deriving 57 kDa and 63 kDa polypeptides for BCAGPS and BCAGPL, respectively, which showed significant similarity to those of other dicot plants. Also, However, the deduced amino acid sequence of BCAGPL has a unique feature. That is, it contains two regions (Rl and R2) lacking in all other plant enzymes. This is the first report of BCAGPL containing Rl and R2 among plant large subunits as well as small subunits. From the genomic Southern analysis and BAC library screening, we inferred the genomic status of BCAGPS and BCAGPL gene.

• Animal cells and systems
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• v.1 no.1
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• pp.135-142
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• 1997

Random sequencing of expressed sequence tags in roots of Chinese cabbage led to isolation of a partial cDNA clone, BR77, which encoded a putative protein kinase. Using the BR77 cDNA as a probe, we isolated a full-length cDNA encoding the Brassica campestris protein kinase 1 (Bcpk1). The Bcpt1 cDNA contained one open reading frame encoding a polypeptide of 439 amino acids. The putative polypeptide consisted of a short N-terminal region and a protein kinase catalytic domain. The catalytic domain of Bcpkl showed a high homology to cAMP- and calcium- phospholipid-dependent subfamilies of serine/threonine protein kineses. Eleven major catalytic domains in protein kineses were well conserved in Bcpk1. However, Bcpk1 contained a unique nonhomologous intervening sequence between subdomains VII and VIII, which was not found in protein kineses of animals and lower eukaryotes. Genomic DNA gel blot analysis showed that Bcpt1 genes might be present as three copies in the Chinese cabbage genome. These imply that Bcpk1 belongs to a plant-specific serine/threonine protein kinase subfamily.

• Journal of Plant Biotechnology
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• v.6 no.4
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• pp.235-239
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• 2004

We studied the effect of genotype, explant, age of explant, medium (plant growth regulators and gelling agents), and standardized an efficient regeneration protocol for inbred lines of Chinese cabbage (Brassica rapa ssp. pekinensis). Of the different concentrations of NAA and BA tested, the combination of $5\;\cal{mg/L}\;BA\;and\;0.5\;\cal{mg/L}$ NAA gave the highest frequency of shoot regeneration. The cotyledonary explants had more shoot regeneration frequency ($\ge40\%$) than the hypocotyl ex-plants. Besides, the cotyledonary explants, excised from the 4-day old seedlings, showed higher shoot regene-ration ($56.7\%$). Of the three gelling agents and their concentrations used, 16 g/L agar was found to be the best for shoot regeneration. Shoot regeneration frequency in-creased significantly by supplementing the medium with $4\;\cal{mg/L}\;of\;AgNO_3$ MS medium devoid of NAA showed higher frequency of rooting in the regenerated shoots than the ones supplemented with NAA. Our improved regeneration protocol will be especially useful for the genetic transformation of Chinese cabbage inbred lines to develop transgenic hybrids.

• The Korean Journal of Food And Nutrition
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• v.33 no.5
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• pp.532-543
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• 2020

This experiment was conducted to assess the high antioxidant activity varieties of Chinese cabbage (Brassica rapa L. ssp. pekinensis) from the 55 accessions. The antioxidant activity of Chinese cabbage were determined by the TPC, TFC, DPPH, ABTS, and chlorophyll, carotenoid contents. The TPC and TFC showed a range of 1.21~4.61 mg GAE/g DW, 0.18~3.09 mg CE/g DW. The DPPH and ABTS assay were in the range of 0.65~4.36 and 1.42~6.91 mg ascorbic acid equivalent (ASCE)/g DW, respectively. The UPLC analysis was performed quantitatively to identify chlorophyll and carotenoid in the Chinese cabbage extract. The levels of the total chlorophyll and total carotenoid were 86.60~1,235.91, and 75.86~490.11 ㎍/g, respectively. The comprehensive differences in the total and individual chlorophyll contents have also been observed among different varieties. These results will be valuable as basic data for the standardization of Chinese cabbage.

• 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.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.745-752
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• 2014

Chinese cabbage (Brassica rapa L. ssp. pekinensis) is an economically important vegetable crop as a source of the traditional food Kimchi in Korea. Although many varieties exhibiting desirable traits have been developed by the conventional selective breeding approach, breeding related to abiotic or biotic stresses, such as a particular pests or diseases, or tolerance to climatic conditions, is likely to be slow. This could be helped by an efficient method for selection from various, rapidly-evolved genetic resources on the basis of molecular markers. In particular, the Brassica genome sequencing project enables genome-wide discovery of genes or genetic variants associated with agricultural traits. We here discuss the recent progress in the field of Chinese cabbage breeding with regard to the application of molecular markers.

• Molecules and Cells
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• v.23 no.3
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• pp.349-356
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• 2007

Simple Sequence Repeats (SSRs) represent short tandem duplications found within all eukaryotic organisms. To examine the distribution of SSRs in the genome of Brassica rapa ssp. pekinensis, SSRs from different genomic regions representing 17.7 Mb of genomic sequence were surveyed. SSRs appear more abundant in non-coding regions (86.6%) than in coding regions (13.4%). Comparison of SSR densities in different genomic regions demonstrated that SSR density was greatest within the 5'-flanking regions of the predicted genes. The proportion of different repeat motifs varied between genomic regions, with trinucleotide SSRs more prevalent in predicted coding regions, reflecting the codon structure in these regions. SSRs were also preferentially associated with gene-rich regions, with peri-centromeric heterochromatin SSRs mostly associated with retrotransposons. These results indicate that the distribution of SSRs in the genome is non-random. Comparison of SSR abundance between B. rapa and the closely related species Arabidopsis thaliana suggests a greater abundance of SSRs in B. rapa, which may be due to the proposed genome triplication. Our results provide a comprehensive view of SSR genomic distribution and evolution in Brassica for comparison with the sequenced genomes of A. thaliana and Oryza sativa.

• Molecules and Cells
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• v.22 no.3
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• pp.300-307
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• 2006

Brassica rapa ssp. pekinensis (Chinese cabbage) is an economically important crop and a model plant for studies on polyploidization and phenotypic evolution. To gain an insight into the structure of the B. rapa genome we analyzed 12,017 BAC-end sequences for the presence of transposable elements (TEs), SSRs, centromeric satellite repeats and genes, and similarity to the closely related genome of Arabidopsis thaliana. TEs were estimated to occupy 14% of the genome, with 12.3% of the genome represented by retrotransposons. It was estimated that the B. rapa genome contains 43,000 genes, 1.6 times greater than the genome of A. thaliana. A number of centromeric satellite sequences, representing variations of a 176-bp consensus sequence, were identified. This sequence has undergone rapid evolution within the B. rapa genome and has diverged among the related species of Brassicaceae. A study of SSRs demonstrated a non-random distribution with a greater abundance within predicted intergenic regions. Our results provide an initial characterization of the genome of B. rapa and provide the basis for detailed analysis through whole-genome sequencing.