• Journal of Environmental Science International
• /
• v.7 no.4
• /
• pp.487-492
• /
• 1998

The experiment was conducted to determine the effects of enhanced UV-B on growth and differential responses among cultivars in soybean. The soybean cultivars subjected to enhanced UV-B irradiation at daily dose of 11.32 kJ $m^{-2}(UV-B_{BE})$ revealed that the growth was significantly depressed. Plant height, leaf number, leaf area and dry weight were inhibited by UV-B irradiation showing differential responses among cultivars used. Danyeubkong seems to be less sensitive to the enhanced W-B irradiation, while Keunolkong more sensitive. Reduction of chlorophyll content was also found significantly greater to Keunolkong. Specific leaf weight an index of leaf thickness, and flavonoid content known as UV-absorbing compounds were significantly Increased in Danyeubkong by UV-B, but those In the other cultivars were not significantly affected. The results indicated that there are cultivar diferences in tile growth and phisiological responses to the enhanced UV-B irradiation and specific leaf weight and UV-absorbing compounds in the leaves were highly related to the sensitivity of soybean by UV-B irradiation.

• Journal of Life Science
• /
• v.16 no.3 s.76
• /
• pp.522-526
• /
• 2006

To investigate the effects of UV-B on fatty acid composition, lipid peroxidation and biochemical defense responses of plant, kidney bean (Phaseolus vulgaris L.) was subjected to enhanced UV-B irradiation [daily dose : 0.02.(No UV-B) and 11.36 (enhanced UV-B) $kJ\;m^{-2};UV-B_{BE}$] for 3 weeks. UV-B drastically inhibited both height and dry weight of kidney bean. The content of malondialdehyde significantly increased by about 50% after 3 weeks of UV-B irradiation. The ratio of unsaturated to saturated fatty acids of kidney bean was increased by UV-B irradiation. Three major polyamines of kidney bean leaves : putrescine, spermidine and spermine, were observed. All of the polyamine contents were increased with UV-B irradiation. These results suggested that enhanced UV-B radiation caused oxidative stress on lipids and biochemical protection responses might be activated to prevent from damaging effects of oxidative stress generated by UV-B irradiation.

• Korean Journal of Weed Science
• /
• v.30 no.2
• /
• pp.135-142
• /
• 2010

To investigate the effects of ultraviolet(UV-B) on growth and biochemical defense responses of plant, garden balsam (Impatiens balsamina L.) was subjected to enhanced UV-B irradiation [daily dose: 0.02 (No UV-B) and 11.34 (enhanced UV-B) kJ $m^{-2}$ ; $UV-B_{BE}$] for 3 weeks. Enhanced UV-B drastically inhibited leaf area as well as dry weight of garden balsam. The content of malondialdehyde was significantly increased by about 50% after 3 weeks of UV-B irradiation. The ratios of dehydroascorbate/ascorbate and oxidized glutathione/reduced glutathione were also considerably increased by UV-B irradiation. Three major polyamines of garden balsam leaves: putrescine, spermidine and spermine were observed. All polyamine contents were increased with UV-B irradiation. The enzyme (superoxide dismutase, ascorbate peroxidase etc.) activities of garden balsam were increased by the UV-B enhancement. Based on the results, enhanced UV-B caused oxidative stress in garden balsam and biochemical protection responses might be activated to prevent from damaging effects of oxidative stress generated by UV-B irradiation.

• Journal of Plant Biotechnology
• /
• v.1 no.2
• /
• pp.117-121
• /
• 1999

Effects of jasmonic acid treatment, UV-B and white light treatment on the anthocyanin biosynthesis and cell growth were investigated using the cell suspension culture system of grape (Vitis vinifera L.). Cell growth was not affected by white light irradiation, while it was remarkably suppressed by UV-B irradiation from 8 to 32 h. Anthocyanin accumulation dramatically increased after 16 h from irradiation of UV-B. Simultaneous treatment of jasmonic acid and UV-B increased anthocyanin accumulation by 10-fold. The cell division was restored when anthocyanin was abundantly accumulated after 32 h from UV-B irradiation. Optimum concentration of jasmonic acid was found to be 5 uM for maximum accumulation of anthocyanin. Application of jasmonic acid to grape suspension cells rapidly induced the expression of CHS gene after 2 h from treatment and showed maximum level at 32 h. Simultaneous treatment of jasmonic acid and light also induced CHS gene expression after 2 h, but the maximum level of CHS transcript was observed at 16 h with white light and 8 h with UV-B exposure. The synergistical effects could be explained by the defense mechanism that UV irradiation is mediated in part by alterations in JA and its signaling pathway.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.158-161
• /
• 2002

UV-B radiation gives harmful effects on plants, such as production of several types of DNA lesions, and growth inhibition. On the other hand, plants have some protective mechanisms, including filtering effect due to accumulation of phenolic compounds in epidermal cells and reactivation of DNA lesions, which are enhanced by UV-B irradiation. We have investigated the mechanism of UV-B effects on plants using cucumber seedlings as plant materials. Cucumber plants were cultivated in an artificially lit growth chamber. Supplemental UV-B irradiation, of which intensity was almost equal to the level of natural sunlight, retarded the growth of first leaves. The growth retardation must result trom the inhibition of cell division and/or cell growth. Microscopical observation of leaf epidermis suggested that the growth retardation might be mainly caused by cell growth inhibition. The retardation was, however, restored within 2 or 3 days after the termination of UV-B irradiation. It is known that UV-B irradiation lowers the activity of photo system II (PS II). In the present experimental conditions, however, UV-B irradiation has little effect on PS II activity as estimated by chlorophyll fluorescence. The stomatal conductance, a major factor determining photosynthetic rate, of first leaves increased during the growth. The increase of stomatal conductance was suppressed by UV-B irradiation and restored by termination of the irradiation. It has not been clear, however, what mechanisms are involved in the suppression of increase of stomatal conductance.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.12
• /
• pp.1937-1943
• /
• 2020

Although classical metabolic engineering strategies have succeeded in developing microbial strains capable of producing desired bioproducts, metabolic imbalance resulting from extensive genetic manipulation often leads to decreased productivity. Thus, abiotic strategies for improving microbial production performance can be an alternative to overcome drawbacks arising from intensive metabolic engineering. Herein, we report a promising abiotic method for enhancing lycopene production by UV-C irradiation using a radiation-resistant ΔcrtLm/crtB+dxs+ Deinococcus radiodurans R1 strain. First, the onset of UV irradiation was determined through analysis of the expression of 11 genes mainly involved in the carotenoid biosynthetic pathway in the ΔcrtLm/crtB+dxs+ D. radiodurans R1 strain. Second, the effects of different UV wavelengths (UV-A, UV-B, and UV-C) on lycopene production were investigated. UV-C irradiation induced the highest production, resulting in a 69.9% increase in lycopene content [64.2 ± 3.2 mg/g dry cell weight (DCW)]. Extended UV-C irradiation further enhanced lycopene content up to 73.9 ± 2.3 mg/g DCW, a 95.5% increase compared to production without UV-C irradiation (37.8 ± 0.7 mg/g DCW).

• Journal of Korean Ophthalmic Optics Society
• /
• v.18 no.3
• /
• pp.253-260
• /
• 2013

Purpose: To investigate the UV-B blocking rate of eyeglasses lens which can prevent enzymes denaturation in cornea. Methods: The denaturation degree of RNase A and catalase, superoxide dismutase (SOD) was determined by using Acrylamide gel electrophoresis after UV-B irradiation of 312 nm for 1, 3, 6, 24 and 96 hours. Also, the inhibitory effect of eyeglasses lens having UV-B blocking rate of 50%, 80%, 95% and 99% on the enzymes denatration was measured. Results: The denaturation of RNase A was induced by 1 hour-irradiation of UV-B. To inhibit RNase A denaturation after UV-B irradiation between 1 hour and 6 hours, UV-B blocking lens of 95% were effective. UV-B blocking lens of 99% suppressed the inhibition of RNase A denaturation after the UV-B exposure between 24 hours and 96 hours. The denaturation of catalase was not induced by 1 hourirradiation of UV-B. To inhibit enzyme denaturation after UV-B irradiation between 1 hour and 6 hours, UV-B blocking lens of 50% were effective. UV-B blocking lens of 95% suppressed the inhibition of enzyme denaturation induced by UV-B irradiation between 24 hours and 96 hours. The SOD denaturation was not induced by UV-B irradiation shorter than 6 hours exposure. The UV-B blocking lens of 50% could inhibit SOD denaturation after the UV-B irradiation for 24 hours. When SOD was exposed to UV-B for 96 hrs, SOD denaturation was inhibited by eyeglasses lens with UV blocking rate higher than 95%. Conclusions: The results demonstrated that the proper UV-B blocking rates of eyeglasses lens to inhibit the enzymes denaturatioin was different according to the types of enzymes and its inhibitory effect was effective only when eyeglasses lens had higher than certain UV-B blocking rate.

• Journal of Environmental Science International
• /
• v.5 no.5
• /
• pp.635-642
• /
• 1996

Rice plants, cv. Koshihikari, were subjected to the biologically effective ultraviolet-B(UV-BBE) radiation {daily dose : 0.0 (control) and 11.5 (enhanced UV-B) KJ m-2} to investigate the effect of enhanced UV-B radiation on lipid peroxidation and to determine whether carotenoids and polyamines are involved in protection mechanism against enhanced UV-B radiation. Enhanced UV-B radiation significantly depressed plant dW weight. Malondialdehyde (MDA) content in rice leaves was increased by about 30% after 6 days of UV-B irradiation. Total carotenoid contents tended to slightly decrease with the UV-B irradiation, even though there was no significance. In rice leaves, 3 major polyamines, putrescine, spermidine and spermine are observed. All of the polyamine contents were increased with UV-B irradiation. The results suggest that enhanced UV- B radiation caused oxidative stress on lipids and that polyamines may serve as a biochemiral protectant against increased UV-B radiation in rice plants.

• Journal of Korea Foresty Energy
• /
• v.19 no.1
• /
• pp.1-6
• /
• 2000

This study was carried out to investigate the growth responses of Pinus densiflora seedlings to enhanced UV-B environment for 16 weeks in the field condition. The seedlings were treated with one of three levels of UV-B dosages - ambient UV-B, ambient + 3.2, and ambient + 5.2 KJ m$^{-2}$day$^{-1}$ and the irradiation was performed at the stage before the germination, the fully expanded cotyledon, and the primary needles grown more than 0.8cm in length of the seedlings, respectively. Enhanced UV-B irradiation reduced the height and the root collar diameter growth, and dry mass production of the seedling, and T/R ratio was increased by the UV-B treatment. Difference in seedling growth was observed by difference in time of the UV-B treatment. Among the seedlings which were treated with ambient - 3.2 KJ m$^{-2}$day$^{-1}$, height and root collar diameter growth was relatively high in the seedling received the UV-B treatment at the stage before the germination. The lowest dry mass production was observed in the seedlings received the UV-B at stage of cotyledon both in two levels of enhanced UV-B treatment. Chlorophyll concentration was reduced by enhanced UV-B irradiation, and chlorophyll a/b ratio was increased by the UV-B treatment.

• Journal of Environmental Science International
• /
• v.6 no.4
• /
• pp.369-378
• /
• 1997

The effects of various intensity of W-B on barley seeding were investigated by PS I and II activities and chlorophyll fluorescence. The Inhibitory effect of UV-B radiation on electron transport activity was Increased as the intensity of UV-B Irradiation was increased. Especially, PS I is more sensitive to UV-B radiation than PS I is. By the addition of uncle electron donor, DPC, to the chloroplasts of the barley seedlings treated with UV-B, the photoreduction of DCPIP was recovered by only 1 IBI on electron transport activity. However, the activity of PS II was Inhibited by 45% by the treatment with UV-B, but recovered it only 11% by the addition of DPC. These suggest that other sites besides the oxidation site of PS II may be affected more by UV-B Irradiation. As the intensify of UV-B was Increased, Fo was Increased while Fv was decreased, and thus Fv/Fm was decreased. This means that photochemical efficiency was reduced. With this parameters, it might be that UV-B radiation affected adversely to around PS II.