• Korean Journal of Agricultural and Forest Meteorology
• /
• v.12 no.3
• /
• pp.173-182
• /
• 2010

This study was conducted to investigate ozone sensitivity of physiological indicators and the difference in ozone tolerance of 8 families of Sophora japonica seedlings on the basis of the standardized physiological indicators. After ozone treatment, photosynthetic parameters, photosynthetic pigments and malondialdehyde (MDA) content, and antioxidative enzyme activities were analyzed from the leaves of S. japonica seedlings. Ozone tolerance indices among 8 families were calculated with the standardized physiological parameters. In addition, the reduction of carboxylation efficiency and apparent quantum yield were observed in the leaves of seven families, except for family No. 6 and 7, respectively. The apparent quantum yield varied from -27% to -61% of the control seedlings. Photosynthetic pigment content differed significantly among 8 families, but was not affected significantly by ozone treatment. Superoxide dismutase (SOD) activity increased from 7% to 64% after ozone exposure, and significant difference existed among 8 families. Ascorbate-peroxidase (APX) activity of 8 families increased by ozone treatment, and the activity of family No. 7 showed the highest increase (218%) in comparison to their respective control plants. On the basis of the standardized indices, family No. 6 showed the lowest tolerance by indicating higher reduction of both photosynthetic parameters and pigment content and lower increase of antioxidative enzyme activities. On the contrary, family No. 7 showed the highest tolerance as indicated by lower reduction of photosynthetic parameters, higher amounts of photosynthetic pigments, and higher enzyme activity.

• Korean Journal of Plant Resources
• /
• v.24 no.1
• /
• pp.105-112
• /
• 2011

The objective of this study was to determine the effect of antioxidant enzyme activity and radical scavenging activities of thirteen kinds of natural plant pigments. The analytic method of antioxidant activities were measured by estimating DPPH free radical scavenging and nitrite scavenging ability activity. The free radical scavenging activity by method using stable free radical DPPH was the highest in the red cabbaged pigment. Addition of ethanol extract 1mg/ml from onion peel pigment displayed remarkable effect on nitrite scavenging ability about 91.9%. Antioxidative enzyme activity was evaluated in terms of superoxide dismutase(SOD), catalase(CAT), and ascorbate peroxidase(APX) activity. The bitter melon pigment had the highest SOD activity of 87.3%. The activities of CAT and APX were higher in the mulberry leave pigment compared with other natural plant pigments. In contrast, CAT activity of plant pigment samples were unaffected. These results suggest that natural plant pigment had the potent biological activities such as antioxidant enzyme activities, and that their activities exhibited differently depending on each kind of pigments.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.14 no.2
• /
• pp.63-70
• /
• 2012

Larix kaempferi and Betula costata seedlings were grown under an elevated temperature ($27^{\circ}C$) for four weeks to understand initial changes on physiological characteristics caused by temperature rising in connection with global warming. At the end of the treatment, growth performance, leaf pigment content, antioxidative enzyme activities and malondialdehyde (MDA) content were measured and analyzed. Relative growth rates of the height of two tree species grown under elevated temperature ($27^{\circ}C$) were lower than those of control ($24^{\circ}C$) and dry weights of leaves, stems and roots were also reduced at higher temperature. Particularly, the root growth reduction of two tree species increased markedly at $27^{\circ}C$ over the study period, which increased the ratio of shoot to root. Under higher temperature, leaf pigment contents decreased, whereas anti-oxidative enzyme activities such as ascorbate peroxidase (APX) and catalase (CAT) increased as compared with the control. But MDA content was not affected by elevated temperature. In conclusion, the elevated temperature leads to root growth reduction, restriction of nutrient uptake from soil and the reduction of leaf pigment contents, which can inhibit the aboveground growth. In addition, higher temperature might act as a stress factor that causes growth reduction through the increase of energy consumption during a growth period.

• Restorative Dentistry and Endodontics
• /
• v.48 no.4
• /
• pp.39.1-39.23
• /
• 2023

Objectives: This study aimed to investigate the effectiveness of different topical/systemic agents in reducing the damage caused by bleaching gel to pulp tissue or cells. Materials and Methods: Electronic searches were performed in July 2023. In vivo and in vitro studies evaluating the effects of different topical or systemic agents on pulp inflammation or cytotoxicity after exposure to bleaching agents were included. The risk of bias was assessed. Results: Out of 1,112 articles, 27 were included. Nine animal studies evaluated remineralizing/anti-inflammatories agents in rat molars subjected to bleaching with 35%-38% hydrogen peroxide (HP). Five of these studies demonstrated a significant reduction in inflammation caused by HP when combined with bioglass or MI Paste Plus (GC America), or following KF-desensitizing or Otosporin treatment (n = 3). However, orally administered drugs did not reduce pulp inflammation (n = 4). Cytotoxicity (n = 17) was primarily assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on human dental pulp cells and mouse dental papilla Cell-23 cells. Certain substances, including sodium ascorbate, butein, manganese chloride, and peroxidase, were found to reduce cytotoxicity, particularly when applied prior to bleaching. The risk of bias was high in animal studies and low in laboratory studies. Conclusions: Few in vivo studies have evaluated agents to reduce the damage caused by bleaching gel to pulp tissue. Within the limitations of these studies, it was found that topical agents were effective in reducing pulp inflammation in animals and cytotoxicity. Further analyses with human pulp are required to substantiate these findings.

• Korean Journal of Weed Science
• /
• v.31 no.2
• /
• pp.134-145
• /
• 2011

The objectives of this study were to investigate fitness difference in growth and rice yield in herbicide-transgenic rice overexpressing Myxococcus xanthus and Arabidopsis thaliana protoporphyrinogen oxidase (Protox) genes and non-transgenic rice. We also aimed to determine whether these fitness differences are related to ALA synthesizing capacity, accumulation of terapyrroles, reactive oxygen species, lipid peroxidation, and antioxidative enzymes at different growth stages of rice. Plant height of the transgenic rice overexpressing M. xanthus (MX) and A. thaliana (AP37) Protox genes at 43, 50, and 65 days after transplanting (DAT) was significantly lower than that of WT. Number of tiller of PX as well as MX and AP37 at 50 and 65 DAT was significantly lower than that of WT. At harvest time, culm length and yield of MX, PX and AP37 and rice straw weight of MX and AP37 were significantly low compared with WT. The reduction of yield in MX, PX, and AP37 was caused by spikelets per panicle and 1000 grain weight, ripened grain, spikelets per panicle, 1000 grain weight, and ripened grain, respectively. On the other hand, 135 the reduction of yield in MX, PX, and AP37 was also observed in another yearly variation experiment. The reduction of rice growth in MX, PX, and AP37 was observed in seedling stage as well as growth duration in field. There were no differences in tetrapyrrole intermediate Proto IX, Mg-Proto IX and Mg-Proto IX monomethyl ester, reactive oxygen species ($H_2O_2$ and ${O_2}^-$), MDA, antioxidative enzymes (SOD, CAT, POX, APX, and GR) and chlorophyll between transgenic lines and wild type, indicating that accumulated tetrapyrrole intermediate and other parameters were not related to growth reduction in transgenic rice. However, ALA synthesizing capacity in MX, PX, and AP37 at one day after exposure to light and 52 DAT was significantly lower than that of WT. Further study is required to elucidate the mechanisms underlying the growth and yield difference between transgenic and WT lines.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.12 no.3
• /
• pp.207-216
• /
• 2010

Individual differences of ozone ($O_3$) resistance for seed production, seed germination and seedling development were examined in this study. Five in each healthy and damaged trees of Pinus thunbergii growing in air polluted area for 12 years were chosen based on visible foliar injury and growth. The cones of P. thunbergii, which were collected from healthy and damaged trees, were analyzed for physical characteristics and seeds from the cones were used to test germination percentage under $O_3$ treatment. The germinated seeds were continuously exposed to $O_3$ treatment and the lipid peroxidation and activities of antioxidative enzymes were determined for both seeds and seedlings. The $O_3$ treatment for seed germination and seedling development were conducted at three conditions: control, 150 ppb and 300 ppb of $O_3$. The non-treated seeds from the damaged trees showed 21.6% lower germination than those from the healthy ones. On the $O_3$ treatment of 300 ppb, seed germination decreased approximately 10% for the healthy trees and 19% for the damaged trees compared to that on the control. The seeds from the healthy trees showed significantly higher activities of superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) than those from the damaged trees. The activities of GR, ascorbate peroxidase (APX), and CAT decreased along with the increasing $O_3$ concentration in two tree grades. Malondialdehyde (MDA) content of seeds was not influenced by $O_3$ treatment for two tree grades. In seedling development, there were no significant differences for length and biomass of needle and root of two tree grades at both the control and 150 ppb of $O_3$. At 300 ppb of $O_3$ treatment, however, the length and biomass of needle and stem decreased for two tree grades but no significant differences was detected in root. The seedlings from the damaged trees were more sensitive to the $O_3$ treatment, showing higher activities of SOD, APX, and CAT and content of MDA compared to those from the healthy tree seedlings. Our results indicate that seed germination and seedling development are vulnerable to increasing $O_3$ concentrations and that attention must be paid to the individual selection of tree species for reforestation.