본 연구에서는 단기간의 UV-A 조사가 시금치(Spinacia oleracea L.)의 생장과 생리활성물질에 미치는 영향을 평가 하였다. 시금치 묘는 200μmol·m-2·s-1 PPFD, white LED, 광 주기 12시간, 온도 20°C, 상대습도 70%, 이산화탄소 농도 500μmol·mol-1의 수직농장 모듈에서 재배되었다. 파종 후 5 주된 묘는 7일 동안 20W·m-2와 40W·m-2의 두 가지 에너지 수 준에서 연속적으로 UV-A(피크파장: 385nm) 조사한 후 생육 특성, 광합성 파라미터, 이미지 형광, 총 페놀 함량, 항산화도, 그리고 총 플라보노이드 함량을 분석하였다. 결과적으로, UV-A20W 처리는 시금치의 생체중과 건물중을 증가시켰다. 하지만, UV-A 처리구와 대조구 사이의 광합성 파라미터에는 유의한 차이가 나타나지 않았다. 광계Ⅱ의 최대양자수율 (Fv/Fm)은 모든 UV-A 처리에서 7일동안 지속적으로 감소했 다. 또한, UV-A20W 처리에서 식물체당 총 페놀 함량과 항산화 도는 처리 7일째 증대되었으며, 총 플라보노이드 함량은 처리 5일째부터 유의적으로 증가하였다. 이러한 결과는 UV-A LED 보광이 수직농장과 같은 폐쇄형 식물 생산 시스템에서 재배되는 시금치의 생장과 품질을 향상시킬 수 있음을 시사 한다.

본 연구는 식용화 팬지의 UV-B 주·야간 처리에 따른 항산화물질 변화와 생장반응을 알아보고자 수행되었다. 식용화 팬지(Viola comuta ‘Purple’, ‘Blue’)를 대상으로 인공 재배기에서 광원을 LED(백색) 120μmol·m-2s-1로 16시간으로 하였으며, 자외선 UV-B(310~320nm)처리는 기존연구에서 UV-B처리 효과가 좋았던 20분을 주간(11:50~12:10)과 야간(23:50~00:10)으로 처리하였다. 처리 결과, 두 품종 모두 대조구와 UV-B 주·야간 처리간의 꽃과 잎의 생체중 및 건물중은 유의한 차 이가 없었으며, ‘Blue’의 야간 UV-B 처리를 제외한 모든 처리구에서 꽃수도 유의차가 없었다. 처리 후 1, 3, 5주차에 분석한 결과, 잎의 엽록소함량은 ‘Purple’의 3주차를 제외한 모든 처리구에서 유의차가 없었으며, 두 품종 모두 Fv/Fm과 NPQ(Non Photochemical Quenching)값이 처리 간 유의차가 없었다. 또한 UV-B 처리 5주차에 활성산소(superoxide, O2 -)의 Nitrotetrazolium blue chloride(NBT) 염색 후 현미경으로 관찰한 결과, 처리 간 차이가 없었다. 항산화물질인 총 플라보노이드 함량을 분석한 결과, ‘Purple’은 3주차까지 대조구보다 주간 UV-B 처리구가 많은 것을 알 수 있었고, ‘Blue’의 경우 5주차까지 유의차는 없었지만 주·야간 UV-B 처리구가 대조구에 비해 높은 것을 알 수 있었다. 안토시아닌 함량은 ‘Purple’의 경우 3주차만 제외하고 야간 UV-B 처리구가 가장 높은 것을 알 수 있었으나, ‘Blue’의 경우 처리 간 유의차가 없었다. 결론적으로, 주·야간 UV-B 20분처리는 팬지 ‘Purple’과 ‘Blue’의 생장에 거의 영향을 주지 않았으며, ‘Purple’의 총 플라보노이드 함량은 처리 3주까지 증가하였다.

This study was conducted to investigate the effect of ultraviolet light (UV-B) on plant growth and petal antioxidants of edible flower pansy (Viola × wittrochiana ‘Rose’ and ‘Yellow’, V. cornuta ‘Purple’). The plants were grown under white LED of 100 μmol·m-2·s-1 PPFD and treated by UV-B of 10, 20 and 30 minutes per day: UVB-10, UVB-20, and UVB-30 respectively. The plant growth was significantly inhibited as longer UV-B radiation exposure, even ‘Rose’ could not f lower under UVB-30. NPQ increase was observed in all cultivars with longer UV-B irradiation exposure. Also, anthocyanin in ‘purple’ and ‘Rose’ or carotenoid in ‘Yellow’ increased in the petals as longer UV-B radiation exposure. Unexpectedly the contents of total phenol and DPPH did not show the significance in UV-B treatments. In conclusion, the applicable UVB exposure to edible pansy in order to more accumulate antioxidants in petals would be in 20 minutes per day.

UV 경화기술은 라디칼 경화와 양이온 경화로서 크게 2 종류로 분류할 수 있다. 이 기술은 플라스틱과 금속간의 여러 기재에 대한 기능성을 개선하기 위해서 표면처리기술에 주로 초점이 맞추어져 왔다. 반면에, Electron beam 기술은 새로운 기능성 재료들을 창출하기 위해 중합공정뿐만 아니라 가교반응들을 다루었다. 이들 두 기술들은 종래의 열경화성 코팅과 비교할 때, 에너지이용 효율과 환경 친화적이어서, 건조와 경화 공정으로 부터 배출되는 탄산가스와 휘발성 유기물을 대폭 감소시킨다. 이 논문에서는 UV 경화 코팅에서 흔히 사용되는 라디칼 경화기술과, 최근의 있는 양이온 경화와 관련된 기술을 다룬 리뷰 논문이다.

Why do two-spotted spider mites (Tetranychus urticae) inhabit on the underside of leaves? Why are diapause females orange? A possible key to answering these questions is ultraviolet (UV) radiation. UV radiation directly damages DNA and produces reactive oxygen species (ROS). ROS also damages DNA, dissociates proteins, and oxidizes lipids. Because mites are small, the UV/ROS-induced damage would be lethal to mites. In non-diapause females, mortalities under UV-C (250 nm) at 0.6 W m–2 and UV-B (300 nm) at 2.4 W m–2 were significantly higher than those under continuous darkness (DD; control). Oviposition rates in such treatments were significantly lower than those under DD. No significant effects for mortality and oviposition rate were observed under UV-A (350 nm) even when the intensity was as high as 2.4 W m–2. In diapause females, the differences in mortalities between all types of UV radiation and DD were not significant. Interestingly, more than half of diapause females escaped from leaf disks under all types of UV radiation, and the escape rates were significantly higher than those under DD and those for non-diapause females. This suggests that diapause females exhibit negative phototaxis. Mites inhabit the underside of leaves in summer with dense vegetation. Most of UV radiation is absorbed and reflected by leaves. Therefore, the underside of leaves is considered a suitable environment for mites to avoid UV radiation, particularly UV-B (UV-C is completely absorbed by the ozone layer). In autumn, leaves start turning yellow and red as winter approaches and finally, fall. During this phenological event, the UV-B level in the plant canopy would increases dramatically while female mites enter diapause with a change in their body color from yellow-green to orange. It is known that the orange color is mainly due to the accumulation of β-carotene, which plays a role as a scavenger of ROS. Therefore, low mortalities observed in diapause females under UV-C and UV-B may be a result of β-carotene accumulation or merely due to the increase in the escape rate. Therefore, whether the escaped diapause females are resistant to UV-C and UV-B damage needs to be confirmed. Our findings suggest that UV radiation is utilized as an effective non-chemical measure to reduce the mite population and that the selection of habitat and change in body color is the mite’s strategy to reduce the deleterious effects of UV-B.

The UV-B sensitivity was tested for the intertidal species Chondrus ocellatus from Korea, by measuring photosynthesis estimated as effective quantum yield (ΦPSII) of photosystem II (PS II), growth and content and composition of photosynthetic pigm

남극에 생육하는 5종의 홍조류(Curdiea racouitzae, Gigartina skottsbergii, Mazzaella obovata, Myriogramme manginii, Palmaria decipiens)를 대상으로 인공 중파 자외선과 태양광선에 대한 종별 생리적 반응을 광합성이라는 파라미터를 사용하여 조사 연구하였다. 실험실연구 결과, 종간에 중파 자외선에 대한 내성 차이가 확인되었으며 이러한 차이는 각 종들이 채집되기 전에 서식하고 있었

본 연구는 자외선 차단지수(Sun protection Factor, SPF) 측정 시험에서 피험자의 안전을 확보하고 정확한 시험결과를 통해 향후 자외선 조사시험의 기초 데이터 확보 및 연구자료 마련을 목적으로 하였다. 피부유형 기준표에 따라 피험자의 피부유형 Ⅰ, Ⅱ, Ⅲ 형에 해당되는 피험자 395명을 대상으로 하였다. 색차계를이용하여 피부색을 측정한 뒤 ITA (Individual Typology Angle) 값을 계산하고 그 값이 28 이상인 사람을대상으로 편안한 자세를 취하도록 하여 자외선을 60 s 간 조사한 후 24 h 뒤 피험자의 홍반 상태를 판정하였다.전면에 홍반이 나타난 부위에 조사한 UVB의 광량 중 최소량을 최소홍반량(Minimal Erythema Dose, MED)으로 하였다. 통계학적 분석은 Statistical Package for the Social Sciences 프로그램을 사용하였다. 피부 유형이높아질수록 MED 값이 증가하여 피부색이 어두워질수록 MED가 증가한다는 결과를 얻을 수 있었다. 또한 여성이 남성보다 높은 MED로 여성이 남성보다 어두운 피부유형을 가진 것으로 나타났고, 연령별 MED는 피부타입별 모든 연령대에서 연관성이 없었으나 이 같은 결과를 단정 짓기에는 성별, 연령대별 피험자 수가 적어 통계적유의성을 뒷받침하는데 한계가 있을 것으로 생각된다. 본 연구를 통해 얻은 피부유형별 MED 측정값은 자외선차단제를 사용하기 전 MED 값을 예상하여 자외선차단제의 효능 평가 시 비교, 판독을 할 수 있는 기준이 되므로임상에 안전하게 적용할 수 있는 기초자료로써 유용하게 쓰일 수 있을 것이다.

The present study was conducted to determine the effect of hexaconazole (HEX), a triazole fungicide, on the growth, yield, photosynthetic response and antioxidant potential in cucumber (Cucumis sativus L.) plants subjected to UV-B stress. UV-B radiation and HEX were applied separately or in combination to cucumber seedlings. The growth parameters were significantly reduced under UV-B treatment, however, this growth inhibition was less in HEX treated plants. HEX caused noticeable changes in plant morphology such as reduced shoot length and leaf area, and increased leaf thickness. HEX was quite persistent in inhibiting shoot growth by causing a reduction in shoot fresh and dry weight. HEX noticeably recovered the UV-B induced inhibition of biomass production. Significant accumutation in anthocyanin and flavonoid pigments in the leaves occurred as a result of HEX or UV-B treatments. HEX permitted the survival of more green leaf tissue preventing chlorophyll content reduction and higher quantum yield for photosystemⅡ under UV-B exposure. HEX treatment induced a transient rise in ABA levels in the leaves, and combined application of HEX and UV-B showed a significant enhancement of ABA content which activates H2O2 generation. UV-B exposure induced accumulation of H2O2 in the leaves, while HEX prevented UV-B induced increase in H2O2, indicating that HEX serves as an antioxidant agent able to scavenge H2O to protect cells from oxidative damage. An increase in the ascorbic acid was observed in the HEX treated cucumber leaves affecting many enzyme activities by removing H2O2 during photosynthetic processes. The activities of antioxidant enzymes including catalase(CAT), ascorbate peroxidase(APX), superoxide dismutase(SOD) and peroxidase(POD) in the leaves in the presence of HEX under UV-B stress were higher than those under UV-B stress alone. These findings suggest that HEX may participate in the enhanced tolerance to oxidative stress. From these results it can be concluded that HEX moderately ameliolate the effect of UV-B stress in cucumber by improving the components of antioxidant defense system.

The effect of nitric oxide (NO) on antioxidant system and protective mechanism against oxidative stress under UV-B radiation was investigated in leaves of maize (Zea mays L.) seedlings during 3 days growth period. UV-B irradiation caused a decrease of leaf biomass including leaf length, width and weight during growth. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated UV-B stress induced growth suppression. NO donor permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem Ⅱ than in non-treated controls under UV-B stress, suggesting that NO has protective effect on chloroplast membrane in maize leaves. Flavonoids and anthocyanin, UV-B absorbing compounds, were significantly accumulated in the maize leaves upon UV-B exposure. Moreover, the increase of these compounds was intensified in the NO treated seedlings. UV-B treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide (H2O2) in maize leaves, while NO donor prevented UV-B induced increase in the contents of malondialdehyde (MDA) and H2O2. These results demonstrate that NO serves as antioxidant agent able to scavenge H2O2 to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, catalase (CAT) and ascorbate peroxidase (APX) in maize leaves in the presence of NO donor under UV-B stress were higher than those under UV-B stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3- oxide (PTIO), a specific NO scavenger, to the maize leaves arrested NO donor mediated protective effect on leaf growth, photosynthetic pigment and free radical scavenging activity. However, PTIO had little effect on maize leaves under UV-B stress compared with that of UV-B stress alone. Nω -nitro-L-arginine (LNNA), an inhibitor of nitric oxide synthase (NOS), significantly increased H2O2 and MDA accumulation and decreased antioxidant enzyme activities in maize leaves under UV-B stress. This demonstrates that NOS inhibitor LNNA has opposite effects on oxidative resistance. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative stress induced by UV-B radiation and thus confer UV-B tolerance.

This study was conducted to examine the physiological and biochemical responses against UV-B radiation in the seedling of 15 different rice cultivars, having the different physiological sensitivities. Out of 15 rice cultivars tested, moderate and susceptible groups showed significant decreases in biomass and RGR (relative growth rate). Contents of total chlorophyll were reduced remarkedly by irradiation of UV-B. In all rice cultivars tested, the content of chlorophyll a was strongly decreased, while the contents of chlorophyll b were slightly reduced without showing clear different among three groups and 15 cultivars. Carotenoid content was largely reduced by UV-B radiation, whereas polyamine content was moderately increased. The contents of MDA (malondialdehyde) that reflect the level of lipid peroxidation of cell membranes were clearly increased by UV-B stress, showing higher content in susceptible cultivars than moderate and torelant cultivars. The physiological important parameters highly related to visible injury were leaf color, chlorophyll, carotenoid, and lipid peroxidation, whereas biomass and polyamines were not closely correlated. Based on this results, it was concluded that changes of visible injury and the contents of chlorophyll and MDA could be adequately applied and utilized as physiological indicators to UV-B radiation

In order to investigate low molecular antioxidants synthesized by enhanced UV-B radiation, we used the seedlings of two rice varieties. Woonjangbyeo, UV-tolerant, and Hwajoongbyeo, UV-susceptible, were subjected under supplemental UV-B irradiation. When rice seedlings were irradiated with UV light for short period, biosynthesis of total phenolic compound, ascorbate and glutathione were momently reduced. With an increase of UV-B radiation, however, those were slightly synthesized. The content of lipid peroxides in UV-challenged rice leaves was considerably increased after 12 hrs of UV-B treatment. Lipoxygenase activity under supplemental UV-B radiation was differently responded on rice varieties.

The concerns on the crop damage by ultraviolet (UV) radiations is increasing owing to the decrease of their absorbing stratospheric ozone in the tropospheric. Cultivar differences on early growth of UV radiation among five Korean rice cultivars, four japonica types and one Tongil type (indica-japonica cross hybrid), were studied. Pot-seeded rice plants were grown under four different radiation conditions, i.e., visible radiation only, visible radiation with supplemented with high or low dose of UV-B (280~320 nm in wavelength) and UV-C (less than 280 nm in wavelength). The inhibitory degree on plant height, shoot and root weight and length of leaf blade and leaf sheath were determined at 40 days after seeding. UV-C showed the most severe inhibitory effect on the degree of biomass gain and leaf growth in most cultivars examined, followed by high UV-B and low UV-B. Among the cultivars used, the Kuemobyeo was the most sensitive cultivar and had not repair or showed resistance ability to continued irradiation of UV radiation. However, Janganbyeo and Jaekeon showed different responses that the elongation of leaf blades was promoted on 2nd and 3rd leaves and inhibited on 4th and 5th leaves but this inhibitory degree was reduced on 6 th and 7th leaves. Such tendency on leaf growth means that both cultivars had low sensitivity and most resistant ability to continued irradiation of UV radiation. While Tongil showed different response to enhanced UV radiation, ie., low UV-B promoted leaf growth but the inhibitory was severely increased by continued irradiation of high UV-B and UV-C, which means that Tongil had high threshold of UV radiation for response as an inhibitory light of plant growth. The results of this study indicate that the differences on sensitivity or resistant to the effects of UV radiation were existed among Korean rice cultivars