The effect of salicylic acid(SA) on antioxidant system and protective mechanisms against UV-B induced oxidative stress was investigated in cucumber(Cucumis sativus L.) leaves. UV-B radiation and SA were applied separately or in combination to first leaves of cucumber seedlings, and dry matter accumulation, lipid peroxidation and activities of antioxidant enzymes were measured in both dose and time-dependant manner. UV-B exposure showed reduced levels of fresh weight and dry matter production, whereas SA treatment significantly increased them. SA noticeably recovered the UV-B induced inhibition of biomass production. UV-B stress also affected lipid peroxidation and antioxidant enzyme defense system. Malondialdehyde(MDA), a product of lipid peroxidation, was greatly increased under UV-B stress, showing a significant enhancement of a secondary metabolites, which may have antioxidative properties in cucumber leaves exposed to UV-B radiation. Combined application of UV-B and SA caused a moderate increase in lipid peroxidation. These results suggest that SA may mediate protection against oxidative stress. UV-B exposure significantly increased SOD, APX, and GR activity compared with untreated control plants. Those plants treated with 1.0 mM SA showed a similar pattern of changes in activities of antioxidant enzymes. SA-mediated induction of antioxidant enzyme activity may involve a protective accumulation of H2O2 against UV-B stress. Moreover, their activities were stimulated with a greater increase by UV-B+SA treatment. The UV-B+SA plants always presented higher values than UV-B and SA plants, considering the adverse effects of UV-B on the antioxidant cell system. ABA and JA, second messengers in signaling in response to stresses, showed similar mode of action in UV-B stress, supporting that they may be important in acquired stress tolerance. Based on these results, it can be suggested that SA may participates in the induction of protective mechanisms involved in tolerance to UV-B induced oxidative stress.

“Neulbora” is a new leaf vegetable perilla (Perilla frutescens (L.) Britton) variety developed from a cross between Ipdeulkkae1/YCPL173 and YCPL199 at the Yeongnam Agricultural Research Institute, NICS, RDA, in 2005. Wrinkled leaf shape and purple color o

“Saebora” is a new leaf vegetable perilla (Perilla frutescens (L.) Britton) variety developed from a cross between “Ipdeulkkae1” and YCPL199 at the Yeongnam Agricultural Research Institute, NICS, RDA, in 2004. Purple backside leaf color is a very importan

“Sangbeak” (Perilla frutescens (L.) Britton), is a cultivar for leaf vegetable, from a cross between YPL5 (Ipdeulkkae1/ YCPL187) and “Namcheon” at the National Yeongnam Agricultural Experiment Station (NYAES), RDA, in 2003. The size of fully grown leaf is a important trait in delayed harvesting. The maximum leaf size of “Sangbeak” is 18.5cm, smaller than 21.4cm of a check cultivar, “Ipdeulkkae”1, leading to the constant leaf quality in delayed harvest. The fresh leaf yield of “Sangbeak” is 6% higher than that of “Ipdeulkkae 1” (5029 vs. 4742 kg/10a). For the leaf production, “Sangbeak” could be grown in whole area of South Korea. However, because of its late maturity, seed production culture is available in South Gyeongsang and South Jeolla provinces.