• Journal of Sensor Science and Technology
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• v.31 no.6
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• pp.418-422
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• 2022

α-pinene is a natural volatile organic compound secreted by coniferous trees to protect themselves from attacks by insects, microorganisms, and viruses. Recently, studies have reported that α-pinene possesses pharmacological effects on various biological reactions such as anxiolytic, sleep-enhancing, anti-nociceptive, and inflammatory activity. Thus, forest bathing has recently received great attention as a novel therapy for treating severe diseases as well as psychological issues. However, appropriate places and timings for effective therapies are still veiled, because on-site monitoring of α-pinene gas in forests is barely possible. Although portable chemosensors could allow real-time analysis of α-pinene gas in forests, the α-pinene sensing properties of chemosensors have never been reported thus far. Herein, we report for the first time, the α-pinene sensing properties of an oxide semiconductor gas sensor based on rhombohedral In₂O₃ (h-In₂O₃) nanoparticles prepared by a microwave-assisted hydrothermal reaction. The h-In₂O₃ nanoparticle sensor showed a high response to α-pinene gas at ppm levels, even under humid conditions (for example, relative humidity of 50 %). The purpose of this research is to identify the potential of oxide semiconductor gas sensors for implementing portable devices that can detect α-pinene gas in forests in real-time.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.495-501
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• 2011

Bacterial strains were isolated from forest soils of Halla mountain, Jeju island in Korea. The soil samples were collected at each altitude of 100m from 1,000 m above sea level. Total 398 strains were isolated and tested for their physiological characteristics of antagonistic and proteolytic activities, and auxin production. Among the isolates, 172 strains were selected as antifungal strains showing antagonistic activity against at least one of 8 plant fungal pathogens (Alternaria alternata, Botrytis cinerea, Collectotrichum acutatum, Fusarium oxysporum, Phytophthora capsici, Pythium ultimum and Sclerotinia sclerotiorum). In addition 203 strains for proteolytic activity and 26 strains for auxin production were characterized for further study. Je28-4 (Rhodococcus sp.) were showed 80% of control value against tomato gray mold in vivo. Thus, it is suggested that soil bacteria isolated from forest soils of Halla mountain can be important sources of bioactive compounds for improving plant growth or promising biocontrol agents.

• Korean Journal of Medicinal Crop Science
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• v.25 no.5
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• pp.290-295
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• 2017

Background: Senna tora is a flowering plant in the legume family Fabaceae. Its seeds are roasted and consumed as tea in Asia, to reduce inflammation in the liver and improve eyesight. Thus, it has been considered as an important medicinal crops in Asia. However, breeding trials to improve its genetic properties are rare. Mutation breeding by gamma ray is known to be an effective and highly successful approach for the generation of agronomically useful cultivars. Here we analyzed the effects of several dosages of gamma ray on the biological conditions of Senna tora seeds. Methods and Results: The germination rate and growth patterns of Senna tora were examined following irradiation with gamma ray at 100, 200, 300 and 400 Gy. The total phenolic compound contents and antioxidant activities of Senna tora were analyzed. Germination increased at 100 and 200 Gy in the M1 and M2 generations compared with that of the control (M0). The total phenolic compound contents and antioxidant activity of the seeds significantly decreased as the radiation dosage increased above 100 Gy in the M1 generation. Conclusions: Senna tora, irradiated with gamma ray at dosages 100, 200, 300, and 400 Gy, showed maximum germination rate at 200 Gy in the M2 generation. Plant height and leaf size gradually decreased with increasing gamma ray intensity in the M2 generation. The total phenolic compound contents decreased significantly at 400 Gy, and the related antioxidant activity was also decreased as the radiation dosage increased.

• Journal of Ginseng Research
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• v.37 no.3
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• pp.355-360
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• 2013

Ginseng cultivated and grown naturally under mountainous forest is formally called "Lin-Xia-Shan-Shen" (LXSS) and grown in manual condition is called garden ginseng (GG) according to Chinese pharmacopoeia (2010 edition). Usually the growing condition of LXSS is similar to wild ginseng and mostly used in Chinese folks in ancient times. The antioxidant properties of LXSS with different growing years were evaluated by their inhibitions of thiobarbituric acid-reactive substance (TBA-RS) formation in liver homogenate and 2, 2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging activity comparing with those of GG. The inhibitions of different polar extracts (n-butanol and water) of LXSS and GG on TBA-RS formation were also evaluated. The results showed that the antioxidant effects of LXSS were higher than those of GG and the TBA-RS formation inhibition of LXSS with longer growing years were stronger than those with shorter growing years, while the DPPH-radical scavenging activity of LXSS did not show significant difference with the change of the growing year. The results indicated that the inhibitory effect of TBA-RS formation and the DPPH-radical scavenging of LXSS were correlated with the contents of ginsenosides. In adddition, the starch contents of LXSS and GG were determined by micro-amount method with spectrophotometer. It showed that the starch content in GG was higher than that of LXSS whose starch decreased gradually with the growing year.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.2
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• pp.72-79
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• 2002

This study was conducted to compare the physiological and biochemical responses of four Betula species in response to ozone, and to find out the relationship between ozone uptake rate and photosynthesis or antioxidant activity. One-year-old seedlings of four Betula sp, B. costata, B. davurica, B. platyphylla var, japonica, and B. ermani, exposed to 100 pub ozone concentration for 8h day$^{-1}$ for 5 weeks in fumigation chamber. Ozone uptake rate, photosynthesis, SOD and GR activity were measured in the leaves of four species once a week. Cumulative ozone uptake rate was largest in the loaves of B. costata(53.8 mmol m$^{-2}$ ), smallest in the leaves of B. davurica(35.5 mmol m$^{-2}$ ). Photosynthesis of four Betula sp. exposed to ozone reduced relative to control, but the photosynthetic responses with changing stomatal conductance were different among species. Ozone exposure increased SOD activities of four species at the early exposing period, but after a critical point SOD activity decreased gradually. GR activity of B. costata was similar to the change of SOD activity, but the others showed the different patterns from B. costata. In conclusion, decreasing both SOD and GR activity at the critical point, B. costata may be sensitive species in response to ozone. In contrast, the others may be resistant species, which gradually increase GR activity following ozone exposure. GR activity was not always in accord with the change of SOD activity against ozone uptake, and the different responses between species were supposed to be affected by the cumulative ozone uptake.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.2
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• pp.47-57
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• 2008

Physiological and biochemical changes of five species of genus Quercus exposed to ozone fumigation were investigated to assess their tolerance against ozone toxicity. At the end of 150 ppb ozone fumigation, chlorophyll contents, photosynthetic characteristics, malondialdehyde(MDA) and antioxidative enzyme activities were measured in the leaves of five Quercus species(Quercus acutissima, Q. aliena, Q. palustris, Q. serrata, and Q. variabilis). Chlorophyll and carotenoid contents, net photosynthesis and carboxylation efficiency decreased after ozone treatment, indicating that $O_3$-exposed plants underwent physiological inhibition. The reduction rate of total chlorophyll contents and carboxylation efficiency were respectively 15% and 34% for Q. aliena and 38% and 62% for Q. variabilis. The amount of MDA increased with the highest increase rate of 140% in Q. acutissima which also showed the highest increase rate(60%) of superoxide dismutase(SOD). Ascorbate peroxidase(APX) activity increased in Q. variabilis, Q. serrata and Q. acutissima by ozone treatment. Based on our results, ozone tolerance of the five Quercus species was ranked as Q. aliena>Q. palustris>Q. serrata>Q. variabilis>Q. acutissima. We concluded that chlorophyll contents, photosynthesis, MDA content and antioxidative enzymes were the important physiological markers for tolerance against ozone stress, which were closely related with one another.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.33-40
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• 2016

This study is focused on the evaluation of growth parameters, total polyphenol content (TPC), chlorophyll content as well as the DPPH (1,1-diphenyl-2-picryhydrazyl) free radical scavenging activity of young barley seedling (YBS) affected by elicitation. Salicylic acid (SA), methyl jasmonate (MJ), amino acid liquid fertilizer (ALF) and microbial metabolism activator (MMA) were used. Elicitation was conducted for two times and various concentrations were used in this study. The result revealed that, MJ 1 ml/L treated-YBS gave the longest seedling length of 1.33 cm, followed by the ones treated with SA 1.38 mg/L and ALF 2 ml/L, respectively. ALF 3 ml/L treatment gave the highest fresh weight of 10 seedlings, followed by MJ 5 ml/L and SA 13.8 mg/L treatment with 1.56 g, 1.55 g and 1.53 g respectively. SA 138.12 mg/L elicitor treated-YBS gave the highest Chl a, Chl b content of $8.57{\mu}g/mg$ and $3.83{\mu}g/mg$, respectively while the highest carotenoid content was found in MJ ml/L treatment with $1.62{\mu}g/mg$. Among elicitor treated-YBS, SA showed better TPC. The highest TPC was found in SA 1.38 mg/L treatment with 18.82 mg/g TAE. Likewise, SA 1.38 mg/L showed the highest DPPH free radical scavenging activity among all the treatments. However, the lowest TPC was found in ALF 1ml/L treated-YBS with 9.46 mg/g TAE, which was even lower than the control (14.31 mg/g TAE).

• Korean Journal of Agricultural Science
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• v.16 no.1
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• pp.36-43
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• 1989

Out of 826 isolates of Streptomyces isolated from different soils, their distribution and antibiotic productivity were investigated. Distribution of the organism in the soil was affected by the soil conditions and plants. The highest isolation frequency was occurred from Quercus forest, Robinia forest and grass field, while soils from orchards and cultivating fields showed low density of Streptomyces. More than 49% of the isolates showed antibacterial activity against Bacillus subtilis, Erwinia carotovora subsp. carotovora and Xantomonas campestris pv. oryzae and about 40% of the isolates showed antiyeasty activity against Saccharomyces cerevisiae but only a few isolates showed antibiotic activity against E. coli and Pseudomonas solanacearum. Forty isolates of the Streptomyces showed strong antifungal activity against Pyricularia oryzae. Rate of isolation of Streptomyces was the highest on starch agar among the eight media tested. Antibiotic productivity of the isolates was the highest on potato sucrose agar medium among the 5 media tested.

• Journal of Forest and Environmental Science
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• v.33 no.4
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• pp.322-329
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• 2017

As a result of contemporary environmental concerns, a number of studies from plants' tissues as one of the alternatives to conventional chemicals are increasingly investigated. In tandem with these trends, Lagenaria breviflora (LB) fruit, reputed as antiviral and depilatory agents in the Yoruba folkloric medicine was examined on Vitex doniana wood to ascertain its antifungal activity. Fungicides of 25%, 50%, 75%, and 100% LB fruits formulations (concentrations) were developed through simple one-step mechanical-forming process, including control. In this study, the yield, the chemical compositions, the absorption capacity of the fungicides and wood weight losses (WWL) analysis were evaluated to investigate the antifungal activity of LB fruit on wood. The fruit extract yielded 35.4% of fresh juice weight. LB fruits contained total: alkaloids ($8.78{\pm}0.21mg/mL$), flavonoids ($2.01{\pm}0.02mg/mL$), phenol ($7.42{\pm}0.09mg/mL$), saponins ($11.00{\pm}0.10mg/mL$) and tannins ($5.47{\pm}0.05mg/mL$) contents. All the formulations provided effective protection against the tested wood fungi compared to control. Interestingly, the antifungal activity of 50% and 25% formulations of 6.8% WWL and 9.9% WWL satisfied the excellent fungal resistance class description against white rot fungus (Ganoderma lucidum) and brown rot fungus (Fibroporia vaillantii), respectively according to ASTM D 2017. These results thus, support LB fruit as a strong potential source of natural antifungals for industrial wood production.

• The Korean Journal of Mycology
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• v.42 no.4
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• pp.322-327
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• 2014

Subculture is the most common method for preservation fungi, but has a disadvantage of accumulation of spontaneous mutations during the repeated subculture. To reduce the subculture frequency, the effect of preservation period at $4^{\circ}C$ in a slant culture was examined on the mycelia growth and lignocellulolytic enzyme activities of various basidiomycetes. Mushrooms, including Stereum ostrea, Coprinellus micaeus, Trametes versicolor, Hypholoma fasciculare, Wolfiporia extensa, Pleurotus pulmonarius, Piptoporus betulinus and Ganoderma applanatum were not affected by the preservation period more than two years, indicating that they can be maintained by subculture every two years. Some other tested fungal strains showed a significant decrease in both viability and enzyme activity when they were maintained for two years, suggesting that they should be subcultured at least once in a year. A little correlation was found between the recovery of mycelial growth and extracellular enzyme activity. In conclusion, mycelial activity and enzyme activity according to storage period is expected to be a way of deciding on subculture times for fungal preservation.