• Journal of Plant Biology
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• v.28 no.1
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• pp.69-77
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• 1985

The degree of The degree of The degree of ${Zn}^{2+}$ effect on the photosynthetic electron transport and photophosphorylation activities in barley chloroplasts has been tested.${Zn}^{2+}$treatment was done in the 2 ways. One was that it was added into the chloroplasts suspensions isolated from the plants grown under the normal ${Zn}^{2+}$level (10$^{-6}$ M). The other was that the different concentrations of ${Zn}^{2+}$was applied in each growth medium. Then, it was not added into the chloroplasts suspensions isolated from the plants. PS II activity in both way of the treatments was more severely inhibited than PS I by the increment of ${Zn}^{2+}$ concentration. The photophosphorylation activity measured by pH measurement was gradually decreased with the increase of ${Zn}^{2+}$concentration in both ways, too. However, it was shown that M $n^{2+}$ could be near fully overcome the inhibitory effect of ${Zn}^{2+}$in PS II, and $Mg^{2+}$ could also reduce the Z $n^{2+}$ inhibition in the photophosphorylation. In the low concentrations of $Mg^{2+}$ (3 to 5$\times$10$^{-3}$ M) in the suspension, ${Zn}^{2+}$(2$\times$10$^{-5}$ M) could increase the activity of photophosphorylation. As compares to other cations, Z $n^{2+}$ caused less inhibitory effect on the photophosphorylation activity than Cu, Cd, but more than Pb and Ni. It may be assumed that a complex from reaction of Z $n^{2+}$ and mercaptoethanol was produced and it could reduce the stability of CPI band during SDS-PAGE.effect on the photosynthetic electron transport and photophosphorylation activities in barley chloroplasts has been tested. Z $n^{2+}$ treatment was done in the 2 ways. One was that it was added into the chloroplasts suspensions isolated from the plants grown under the normal Z $n^{2+}$ level (10$^{-6}$ M). The other was that the different concentrations of Z $n^{2+}$ was applied in each growth medium. Then, it was not added into the chloroplasts suspensions isolated from the plants. PS II activity in both way of the treatments was more severely inhibited than PS I by the increment of Z $n^{2+}$ concentration. The photophosphorylation activity measured by pH measurement was gradually decreased with the increase of Z $n^{2+}$ concentration in both ways, too. However, it was shown that M $n^{2+}$ could be near fully overcome the inhibitory effect of Z $n^{2+}$ in PS II, and $Mg^{2+}$ could also reduce the Z $n^{2+}$ inhibition in the photophosphorylation. In the low concentrations of $Mg^{2+}$ (3 to 5$\times$10$^{-3}$ M) in the suspension, Z $n^{2+}$ (2$\times$10$^{-5}$ M) could increase the activity of photophosphorylation. As compares to other cations, Z $n^{2+}$ caused less inhibitory effect on the photophosphorylation activity than Cu, Cd, but more than Pb and Ni. It may be assumed that a complex from reaction of Z $n^{2+}$ and mercaptoethanol was produced and it could reduce the stability of CPI band during SDS-PAGE.effect on the photosynthetic electron transport and photophosphorylation activities in barley chloroplasts has been tested. Z $n^{2+}$ treatment was done in the 2 ways. One was that it was added into the chloroplasts suspensions isolated from the plants grown under the normal Z $n^{2+}$ level (10$^{-6}$ M). The other was that the different concentrations of Z $n^{2+}$ was applied in each growth medium. Then, it was not added into the chloroplasts suspensions isolated from the plants. PS II activity in both way of the treatments was more severely inhibited than PS I by the increment of Z $n^{2+}$ concentration. The photophosphorylation activity measured by pH measurement was gradually decreased with the increase of Z $n^{2+}$ concentration in both ways, too. However, it was shown that M $n^{2+}$ could be near fully overcome the inhibitory effect of Z $n^{2+}$ in PS II, and $Mg^{2+}$ could also reduce the Z $n^{2+}$ inhibition in the photophosphorylation. In the low concentrations of $Mg^{2+}$ (3 to 5$\times$10$^{-3}$ M) in the suspension, Z $n^{2+}$ (2$\times$10$^{-5}$ M) could increase the activity of photophosphorylation. As compares to other cations, Z $n^{2+}$ caused less inhibitory effect on the photophosphorylation activity than Cu, Cd, but more than Pb and Ni. It may be assumed that a complex from reaction of Z $n^{2+}$ and mercaptoethanol was produced and it could reduce the stability of CPI band during SDS-PAGE.ld reduce the stability of CPI band during SDS-PAGE.

• Korean Journal of Remote Sensing
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• v.32 no.4
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• pp.383-401
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• 2016

In this paper, we described the statistical modeling of crop yields using satellite images, climatic datasets, soil property maps, and fertilizer data for the Midwestern United States during 2001-2012. Satellite images were obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS), and climatic datasets were provided by the Parameter-elevation Regressions on Independent Slopes Model (PRISM) Climate Group. Soil property maps were derived from the Harmonized World Soil Database (HWSD). Our multivariate regression models produced quite good prediction accuracies, with differences of approximately 8-15% from the governmental statistics of corn and soybean yields. The unfavorable conditions of climate and vegetation in 2012 could have resulted in a decrease in yields according to the regression models, but the actual yields were greater than predicted. It can be interpreted that factors other than climate, vegetation, soil, and fertilizer may be involved in the negative biases. Also, we found that soybean yield was more affected by minimum temperature conditions while corn yield was more associated with photosynthetic activities. These two crops can have different potential impacts regarding climate change, and it is important to quantify the degree of the crop sensitivities to climatic variations to help adaptation by humans. Considering the yield decreases during the drought event, we can assume that climatic effect may be stronger than human adaptive capacity. Thus, further studies are demanded particularly by enhancing the data regarding human activities such as tillage, fertilization, irrigation, and comprehensive agricultural technologies.

• Korean Journal of Microbiology
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• v.6 no.1
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• pp.22-28
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• 1968

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Biosynthetic activities of nucleic acids, protein and phospholipid in chlorella cells, which were growing in a microelement deficient medium were compared with those of the normal cells by measuring the contents of phosphate, amino acids or UV-absorbing substances in the various cell fractions. When the algae were grown in a molybdenum-free medium, the amounts of phosphate in the acid-soluble fraction of the cells increased, whereas the amounts of alkali-stable protein and RNA decreased compared with the normal cells showing that the synthesis of protein and RNA from the early products of photosynthesis was inhibited. When the algae were grown in a boron-free medium, amounts of alkali-labile protein and phospholipid of the cells decreased, while the amount of phosphate in acid-soluble fraction increased compared with the normal cells showing that the biosynthesis of protein and phospholipid from the early products of photosynthesis was retarded. In general, amounts of protein and RNA in the microelement deficient cells significantly decreased compared with those of the normal cells. Phosphate content in the acid-soluble fraction of the algal cell grown in an zinc, copper, molybdenum, or boron-free medium increased considerably, whereas that of the algal cell grown in an iron or manganese-free medium decreased remarkably compared with that of the control. It is considered, therefore, that molybdenum, zinc, copper and boron etc. play an important role in the biosyntbesis of macromolecule from acid-soluble phosphate compounds, in contrast to the principal action of iron and manganese on the photosynthetic process itself.

• Journal of Environmental Science International
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• v.20 no.12
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• pp.1509-1519
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• 2011

The protective effect of nitric oxide (NO) on the antioxidant system under paraquat(PQ) stress was investigated in leaves of 8-week-old lettuce (Lactuca sativa L.) plants. PQ stress caused a decrease of leaf growth including leaf length, width and weight. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated PQ stress induced growth suppression. SNP 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 PQ exposure, suggesting that NO has protective effect on chloroplast membrane in lettuce leaves. Flavonoids and anthocyanin were significantly accumulated in the leaves upon PQ exposure. However, the rapid increase of these compounds was alleviated in the SNP treated leaves. PQ treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in the leaves, while SNP prevented PQ induced increase in malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that SNP serves as an antioxidant agent able to scavenge $H_2O_2$ to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, superoxide dismutase (SOD) and catalase (CAT) in lettuce leaves in the presence of NO donor under PQ stress were higher than those under PQ stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, to the lettuce leaves arrested SNP mediated protective effect on leaf growth, photosynthetic pigment and antioxidant systems. However, PTIO had little effect on lettuce leaves under PQ stress compared with that of PQ stress alone. The obtained data suggest that the damage caused by PQ stress is in part due to increased generation of active oxygen by maintaining increased antioxidant enzyme activities and SNP protects plants from oxidative stress. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative damage induced by PQ stress and thus confer PQ tolerance.

• Journal of Plant Biology
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• v.35 no.3
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• pp.229-235
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• 1992

Differential expression of the three chlorophyll afb binding (cab) protein gene (cabl, cab2, and cab3) promoters of Arabidopsis thaliana was studied in tobacco plants transformed with cab-CAT (chloramphenicol acetyltransferase) translational fusions. CAT activity was measured to monitor the activities of the cab promoters. The activity of cabi promoter was higher than the other two in transformed tobacco leaves and also in calli and shoots derived from the leaves. Their activities were organ-specific and were the lowest in roots, medium in stems, and the highest in leaves. The relative activity of cabi promoter in stems comparing to it activity in leaves was, however, much higher than the values of cab2 and cab3. When the cab promoter activity was expressed as CAT activity per unit chlorophyll instead of CAT activity per unit protein, the relative cab] promoter activity (stem/leaf) became almost unity. This result suggests that cab2 and cab3 show photosynthetic organ-specificity but cabl does not. Similar result was obtained in the differentiation process of stems and leaves from shoots derived from the transgenic tobacco leaves.leaves.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.165-172
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• 2003

The objectives of this study were to examine the physiological responses to ozone and to measure ozone uptake rates of Betula species exposed to relatively high concentration of pollutants. At the end of the growing season, photosynthesis, pigments contents, antioxidants (SOD and GR) and ozone uptake rates were measured or estimated at the leaves of five Betula species (Betula costata, B. davurica, B. platyphylla var. japonica, B. schmidtii and B. ermanii) exposed to 100ppb ozone concentration. On the termination of the experiment, growth effects were determined by measuring leaf area and dry weights of leaf, stem and root. Ozone treatment showed the significant reduction the leaf area and dry weight of four Betula species, except for B. ermanii. Shoot / root (SR) ratio of five species represented two different types. SR ratio of B. costata and B. davurica were lower than control, in contrast, SR ratio of B. platyphylla var. japonica, B. schimidtii and B. emani, were higher than that of control. The photosynthetic responses of five species were different in responses to ozone exposure. Four species, except for B. emanii, maintained or increased the stomatal conductance, but B. emanii decreased both stomatal conductance and photosynthesis. SOD activities of five species decreased by the ozone exposure, especially B. ermanii showed the largest reduction, GR activities of B. platyphylla var. japonica and B. schmidtii increased, B. costata and B. emanii decreased. Instantaneous ozone uptake rate was the highest at the leaves of B. ermanii and B. costata, ozone uptake per seedling was the highest at the leaf of B. schmidtii and B. emanii. It was concluded that B. costata, B. davurica and B. platyphylla var. japonica, appeared the growth reduction and visible ozone injury, were sensitive species to ozone, and B. schmidtii with the increased antioxidant activity and B. ermanii without the growth reduction were relatively resistant species to high ozone concentration at the early growing stage.

• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.508-515
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• 2008

Sycamore (Platanus occidentalis L.) seedlings were grown under low light intensity and ozone treatments to investigate the role of the light environment in their response to chronic ozone stress. One-year-old seedlings of Platanus occidentalis L. were grown in pots for 3 weeks under low light (OL, $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and high light (OH, $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) irradiance in combination with 150 ppb of ozone fumigation. After three weeks of ozone and light treatment, seedlings were placed in ozone free clean chamber for 3 weeks for recovery from ozone stress with same light conditions to compare recovery capacity. Ozone fumigation determined an impairment of the photosynthetic process. Reduction of leaf dry weight (14%) and shoo/root ratio (17%) were observed in OH treatment. OL treatment also showed severe reductions in leaf dry weight and shoot/root ratio by 48% and 36% comparing to control, respectively. At the recovery phase, OH-treated plants recovered their biomass, whereas OL-treated plant showed reduction in leaf dry weight (52%) and shoot/root ratio (49%). OH-treated plants reached similar relative growth rate (RGR) comparing to control, whereas OL-treated plants showed lower RGR in stem height. However, there were no significant differences in response to those treatments in stem diameter RGR at the recovery phase. Ozone treatment produced significant reduction of net photosynthesis in both high and low light treatments. Carboxylation efficiency and apparent quantum yield in OL-treated plants showed significant reductions rate to 10% and 45%, respectively. At the recovery stage, ozone exposed seedlings under high light had similar photosynthetic capacity comparing to control plants. Antioxidant enzymes activities such as superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) were increased in ozone fumigated plants only under low light. The present work shows that the physiological changes occur in photosynthesis-related parameters and growth due to ozone and low light stress. Thus, low light seems to enhance the detrimental effects of ozone on growth, photosynthesis, and antioxidant enzyme responses.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.190-196
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• 2012

In this study, a total of more than 1,000 bacteria, including 739 species of aerobic bacteria, 80 species of urease producing bacteria and 303 species of photosynthetic bacteria, were isolated from red-pepper field soils located in the Gyeongsan Province of the Republic of Korea. Amongst these, 158 species of aerobic bacteria, 70 species of urease producing bacteria and 228 species of photosynthetic bacteria were found to be auxin producing soil bacteria through quantification analysis with the Salkowski test. The latter groupings were then tested for antifungal activities to ${\beta}$-Glucanase and siderophore using CMC congo red agar and CAS blue agar media. In addition, the selected strains were examined for antifungal activity against various phytopathogenic fungi on PDN agar media. Six strains; BCB14, BCB17, C10, HA46, HA143, and HJ5, were noted for their ability to both produce auxin and act as antifungal substances. 16S rDNA sequence comparison analyses of these six strains identified them as Bacillus subtilis BCB14, B. methylotrophicus BCB17, B. methylotrophicus C10, B. sonorensis HA46, B. subtilis HA143, and B. safensis HJ5.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.61-66
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• 1989

Plants were exposed to different sub-optimal growth temperature regimes for hardening or sprayed with abscisic acid (ABA) before being placed at $10^{\circ}C$ for three days. Comparisons were made with non-treated plants for plant survival, photosynthetic activities and fatty acids composition of phospholipids. The level of endogenous ABA of the hardened seedlings was compared with that in control and ABA sprayed-seedlings. The results of the above experiment were summarized as follows: 1. Compared to non-treated plants, the hardening and ABA treatment resulted in higher plant survival rate and better seedling growth following earlier transplanting. The low temperature hardening which gradually increased the duration of the low temperature treatment at 2-day intervals was more effective than the controled temperature hardening which gradually decreased the temperature from $25^{\circ}C$ to $20^{\circ}C$ and $15^{\circ}C$. 2. The photosynthetic activities of rice leaves after 3-day exposure to $10^{\circ}C$ were higher in hardened and ABA sprayed seedlings than in non-treated plants. The root activities after low temperature treatment were also higher in hardened and ABA sprayed seedlings than in control. 3. Fatty acids of phospholipids in rice plants such as stearic acid and oleic acid were decreased and the highly unsaturated fatty acids, linoleic acid and lenolenic acid were increased by hardening or ABA treatments. It is assumed that the increase of cold tolerance in these plants was due to the higher ratio of unsaturated to saturated fatty acids. Respectively, the ratio was 1.86, 1.97 and 1.80 in plants given controled temperature hardening, the low temperature hardening and ABA treatments. While in control plants, it was 1.17. 4. ABA content in rice seedling given the low temperature hardening treatment was 67.2 ng/g F.W which was approximately twice that of non-treated control, which was 33.9 ng/f F. W., in contrast, the ABA content of the ABA treated seedlings was 91.7 ng/g F. W.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.261-268
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• 1987

A green house experiment was conducted to find out the differences in the amount of biologically fixed nitrogen and kjeldahl nitrogen on the different soil texture, kinds and amounts of fertilizer nitrogen under light (photosynthetic $N_2$-fixation) and dark (heterotrophic $N_2$-fixation) condition in submerged paddy soil. The reults obtained were summarized as follows; 1. The amount of biologically fixed nitrogen per mg carbon from different organic matter was obtained as 0.13 mg in glucose, 0.09 mg in rice straw, and 0.07 mg in refused mushroom compost and barley straw under 60 days of incubation. 2. Nitrogen fixing activities were decreased with increase of fertilizer nitrogen and those tendency was pronounced more in sandy soil with application of urea than that of ammonium sulfate. 3. The application of ammonium sulfate in sandy soil under light condition was increased the photosynthetic $N_2$-fixation and the applied urea was remarkably reduced the heterotrophic $N_2$-fixation in sandy soil. The proportion of biologically fixed total nitrogen after experiment in sandy soil was obtained as 25% for dark(heterotrophic $N_2$-fixation) and 75% for light (photosynthetic $N_2$-fixation) condition. On the other hand, very similar biological $N_2$-fixing tendency was obtained between kinds of nitrogen fertilizer and two light condition in clayey soil. 4. The kjeldahl nitrogen was remarkably decreased after experiment under dark condition with application of urea than that of light condition with ammonium sulfate, and no remarkable decreasing tendency was obtained in clayey soil between two kinds of fertilizer nitrogen. 5. The high significant positive correlationship was obtained between calculated biological nitrogen fixation by acetylene reducing activity and kjeldahl nitrogen after experiment under light (y=0.8488X-5.9632, $r=0.9928^{**}$, n=21) and dark (y=0.8795X-7.1056, $r=0.9782^{**}$, n=21) condition. In this experiment condition, conversion factors of 6:1 was obtained from biological nitrogen fixation to soil nitrogen.