• Korean Journal of Plant Tissue Culture
• /
• v.28 no.3
• /
• pp.153-157
• /
• 2001

Protoplasts were isolated from hypocotyls, cotyledons, and young leaves of Chinese cabbage grown under in vitro environmental condition. An enzyme mixture of 1% Cellulysin and 0.5% Macerozyme in combination with 0.4 M mannitol was most effective condition for protoplast isolation. The highest yield of protoplasts, 7.6$\times$10$^{5}$ protoplast/g of fresh weight, was obtained from the treatment of leaves for 12~16 hours at 27~28$^{\circ}C$ with shaking at 30 rpm. The most suitable medium for an initial cell division was K8p basal medium supplemented with 5 mg/L 2,4-D and 2 mg/L kinetin. Within 7~10 days, protoplasts derived from hypocotyl and cotyledon tissues formed cell colonies. When the cells were grown at the size of 8~10 cells, they were embedded into semi-solid medium containing 0.2% agarose. Calli derived from protoplast culture were transferred to the 100 different types of plant regeneration media, but no completely regenerated plants from inbred lines of Chinese cabbage used for this study wore obtained, though frequent rooting took place in several media tested.

• Journal of Applied Biological Chemistry
• /
• v.44 no.3
• /
• pp.119-124
• /
• 2001

NTR1 gene of Brassica campestris L. ssp. perkinensis encodes a floral nectary-specific methyltransferase. In this study, the NTR1 cDNA was expressed in E. coli to examine the enzymatic characteristics of the protein product. The GST-NTR1 fusion protein was purified to near homogeneity, showing that the size of NTR1 was 44 kDa. The protein reacted specifically with jasmonic acid (JA), consuming methyl group from S-adenosyl-L-methionine (SAM). GC-MS analysis revealed that the compound produced was authentic methyl jasmonate (MeJA), suggesting that NTR1 is an S-adenosyl-L-methionine: jasmonic acid carboxyl methyltransferase. Km values of NTR1 for JA and SAM were 38.0 and $6.4{\mu}M$, respectively. Optimal activity of the NTR1 was observed at $20^{\circ}C$, pH 7.5, in the presence of 100-150 mM KCl. Thus, kinetic properties, thermal characteristics, optimal pH, and ion-dependency of the NTR1 activity were almost identical to those of Arabidopsis JA methyltransferase JMT, indicating that these two proteins are orthologues of each other.

• Journal of Food Hygiene and Safety
• /
• v.18 no.4
• /
• pp.243-250
• /
• 2003

S-methylmethionine, vitamin U levels were affected by cultivars, parts fo Korean Chinese cabbages, and drying methods. Among drying conditions, freeze drying method appeared the best condition to maintain bitamin U content compared to oven and air drying methods. In the case of KOrean Chinese cabbages, outward leaves have high levels of chlorphyll and fiber. From this study, the outward parts contained high levels of vitamin U in two cultivars. Leaf parts were 1.1-21.2 times higher in vitamin U levels than midribs in both cultivars. This difference was shown most distinctively in freeze dried outward parts of Winter Pride cultivar. Like vitmnin U, fee amino acids also showed much higher levels in leaves. Levels of amino acids showed irregulatoy changing patterns at different parts and cultivar of Korean Chinese cabbages with various drying methods, Alanine and threonie appeared relatively aboundant amino acids in most parts of samples. Since no distinctive trends were observed in this rsult, it seems no relationship exists between amon oacids and bitamin U levels. Levels of methionine in differnent parts and cultivars of Korean Chinese cabbages dried with various methods did no show clear relationship with tlevel of vitamin U. Moreover, emthionine was not detected in freeze dired outward leaf parts which were the hithest parts of vitamin U levels in Winter Pride and 55 days cultivar. There were simila levels of methionine between overn and freeze drying. Samples prepared by air drying showed significatly lower levels than those by oven and freeze dryting. Methionine as aprecursor of vitamin U, may play a role in an increase of vitamin U during drying of KOrean Chinese cabbages.

• Food Science and Preservation
• /
• v.13 no.5
• /
• pp.589-595
• /
• 2006

Vitamin U (5-methylmethionine) levels of Chinese cabbages at $4^{\circ}C$ were investigated to establish its physiological characteristics and also amino acids and sugars levels to find out their relationship with vitamin U were determined The levels of vitamin U showed different from parts of Chinese cabbages. The highest value was shown in outward leaf in Wineter Pride (12.70 mg/100 g fresh wt.) and core leaf in 55 Days cultivars (18.60 mg/100 g fresh wt.). leaf pare were 1.7-9.0 times higher in vitamin U levels than those in midribs in both cultivars. levels of vitamin U in stored Chinese cabbages increased with storage time. Moreover, two cultivars used far this experiment showed different pattern during storage. In Winter Pride, vitamin U levels sharply increased in leaf and midrib of cote part during storage. This value reached about 2.5 times for leaf and 4 times for midrib compared to the levels of initial storage time in core part In 55 Days cultivars, outward leaf showed an increased level of vitamin U of 1.8 times compared to that of 1 month storage time. Methionine known as a precursor of vitamin U synthesis did not showed clear relationship with vitamin U levels. Methionine was either not detected or at negligibly low levels in Chinese cabbages during storage. Methionine may not play a role in an increase of vitamin U during storage of Chinese cabbages at $4^{\circ}C$. No clear relationship of free amino acids and soluble sugars for vitamin U accumulation during storage of Chinese cabbages was shown in this study.

• Korean Journal of Organic Agriculture
• /
• v.7 no.1
• /
• pp.115-127
• /
• 1998

Under the visual judgement of consumers, to reduce nitrate intake through vegetables, this experimentation analyzed the content of nitrate, in heading leaf vegetables such as chinese cabbage(Brassica campestris L. ssp. perkinensis (Lour.) Rupr), cabbage(Brassica oleracea L. var. capitata) and lettuce(Lactuca sativa L.) by the leaf number. And the result is summarized as follows In the nitrate content change by the leaf number, the nitrate content is increased as it goes by from inner leaf to outer leaf and the nitrate content in leaf midrib is higher than that in leaf blade. In case of chinese cabbage, the nitrate content in the leaf midrib from the most inner leaf to the most outer leaf changed 40-3,177ppm and in the leaf blade it changed 40-2,887ppm. But the nitrate content in the leaf blade of cabbage from the most inner leaf to the most outer leaf changed 89~2,297ppm and in the leaf blade it changed 25~765ppm. In case of lettuce, the nitrate content change of the leaf midrib by the leaf position was 419~4,349ppm, and in the leaf blade it changed 260~2894ppm. It was conclude that the outer leaf of chinese cabbage, cabbage and lettuce should be removed to keep the lower nitrate intake by population before it is consumed.