The anther (tapetum)-specific gene BcA9 was isolated from Chinese cabbage, Brassica campestris L. ssp. pekinensis cv. Jangwon, using the Arabidopsis tapetum-specific A9 gene as a probe. The DNA and amino acid sequences of the coding region of the BcA9 gene showed high homology with A9 genes from Arabidopsis and B. napus. However, the DNA sequences of the 5' noncoding (promoter) region were different, except for the sequence from -281 to -89. To test the specific activity of this promoter, a plant expression vector, pGR011, was constructed by fusing the BcA9 promoter and the cytotoxic diphtheria toxin A-chain (DTx-A) gene. Several transgenic plants from cabbage, B. oleracea ssp. capitata, were obtained by way of Agrobacterium-mediated transformation. Southern blot analysis indicated that the tapetum-specific BcA9 promoter and DTx-A gene were successfully integrated into the genome of the transgenic cabbage. Under the control of the BcA9 promoter, expression of the cytotoxic DTx-A gene in the tapetal cells of the transgenic plants resulted in male sterile cabbages. Microscopic examination revealed that pollen grains in anthers of the male sterile cabbages had not developed normally, but the vegetative growth and phenotype showed no difference compared to wild-type plants.

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Epidermal growth factor (EGF, 5900 Da) has been reported to have the high efficiency of wound repair. However, the half-life of EGF in the body is too short to exert the biological activity effectively when applied in free forms. Conjugation of the low molecular weight chitosan (LMC) to EGF was carried out to enhance its stability. EGF was conjugated with LMC activated by water-soluble carbodiimide. The formation of EGF-LMC was quantitatively measured by indirect enzyme-linked immunosorbent assay (ELISA). In a study of the thermal and the proteolytic stability of free EGF and EGF-LMC, EGF covalently attached to LMC was found to be more stable than free EGF in thermal and proteolytic stabilities. In animal experiments of which free EGF (control), EGF-LMC (test) and LMC (carrier) diluted in viscous carboxymethyl cellulose (CMC) solution (vesicle) were applied to the incisional wounds in rats, the EGF-LMC conjugates are considered to be potent wound healing agent with mitogenicity and wound-healing property.

Physiological characteristics of five new apple cultivars from the Korean apple breeding program were evaluated as a function of harvest time and storage after harvest. Internal ethylene concentration (IEC), flesh firmness, soluble solids concentration (SSC), and titratable acidity (TA) were measured in 'Summer Dream', 'Summer King', 'Green Ball', 'Picnic', and 'Hwangok' apples at harvest, during shelf life at 20°C, and one day after cold storage at 0.5°C in air. IEC increased during shelf life in 'Summer Dream', 'Summer King', and 'Green Ball' but not in 'Picnic' or 'Hwangok', regardless of harvest time. Flesh firmness decreased towards harvest time and decreased gradually with time in cold storage only in the former three cultivars. In turn, IEC increased during cold storage in the first three cultivars but not for the last two cultivars, irrespective of harvest time. Changes in SSC and TA did not consistently relate to harvest time or storage period but TA tended to decrease as IEC increased. Furthermore, IEC was negatively correlated with flesh firmness except in the 'Green Ball' cultivar but the significance level was much greater in 'Summer Dream' and 'Summer King' (p < 0.0001) than in 'Picnic' (p < 0.01) or 'Hwangok' (p < 0.05) cultivars. Flesh firmness was positively correlated with TA in the first three cultivars but not in the last two cultivars. Overall, the results indicate that cultivars for which IEC increased after harvest had reduced flesh firmness and TA after storage.

Peach and nectarine cultivars have been released worldwide according to regional preference and local adaptability. However, few reports have provided statistical analyses and comprehensive comparisons of Eastern and Western cultivars. In this study, 22 phenotypic characteristics of 120 peach and nectarine cultivars collected from various countries were examined to determine their diversity and relationships. Based on phenological traits, Western cultivars bloomed earlier than Eastern cultivars, with no difference in ripening time. Fruit shape of Eastern cultivars was close to oblate, while fruit weights were similar. In addition, higher soluble solids concentration (SSC) and lower titratable acidity were observed in Eastern cultivars. In health benefit traits, such as total flavonoid concentration, total phenol concentration, and antioxidant capacity, there was no difference between Eastern and Western type. Positive correlation between chilling unit (CU) and latitude of origin was also found. In addition, the CU was closely associated with flowering date. Relationships among the phenotypic characteristics were also found. Ripening date showed significant and positive correlations with fruit development period, fruit weight, and SSC. In general, cultivars with late ripening times tend to produce high-quality fruit with a sweet taste and large size. The evaluation of a large number of cultivars from various regions with phenotypic variability could provide valuable information on regional preference or local adaptability.