• Journal of Ecology and Environment
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• 제30권2호
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• pp.187-193
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• 2007

Higher plants can be categorized as C3, C4 or CAM according to their photosynthetic pathways, and some succulent plants are known to shift their patterns of photosynthesis from C3 to CAM in response to environmental stresses such as salt treatment or water deficiency. To investigate fundamental photosynthetic patterns and the induction of pattern shifts (C3, CAM, C3-CAM etc.) as a result of environmental stresses, we measured the water content, diurnal changes in pH, net $CO_2$ exchange, transpiration rate, total ionic contents, and osmolality of Kalancoe daigremontiana, Sedum kamschaticum and Sedum sarmentosum which belong to Crassulaceae known as representative CAM plant, after 10 days of drought treatment. S. kamschaticum and S. sarmentosum did not show a significant difference in diurnal pH variation in the treatment and control conditions. However, the pH of drought-treated Kalancoe was low at night and high in the daytime, with a pH value between 4 and 5. Typical CAM plants display a net $CO_2$ exchange that increases at night and decreases in the daytime. Kalancoe displayed the predicted pattern. However, S. kamschaticum and S. sarmentosum showed a photosynthetic pattern more typical of C3 plants, and did not show changes in photosynthetic pattern under drought stress. Kalancoe also showed a transpiration rate typical for CAM pho-tosynthesis, whereas the transpiration rates of S. kamschaticum and S. sarmentosum were in the typical range for C3 photosynthesis. Kalancoe had high total ionic contents during the night, which decreased somewhat during the daytime, whereas S. kamschaticum and S. sarmentosum displayed the opposite pattern. This result is similar to the diurnal patterns of changes in pH in the three plant species, which suggests a relationship between pH and ionic contents. S. sarmentosum showed lower osmolality under drought stress than in the control condition, whereas the osmolality of Kalancoe and S. kamschaticum did not differ between conditions. S. sarmentosum may have maintained internal water content by lowering its osmolality and raising its total ionic contents. In conclusion, Kalancoe displayed the characteristic responses of a typical CAM plant, whereas S. kamschaticum and S. sarmentosum displayed aspects of the C3 photosynthetic pattern under drought conditions. These results suggest that S. kamschaticum and S. sarmentosum (Crassulacea) in Korea overcome drought stress by increasing solute and ionic contents internally rather than changing their photosynthetic pattern from C3 to CAM under drought stress.

• KSBB Journal
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• 제6권4호
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• pp.351-361
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• 1991

This study is on the investigation of hydrogen production and substrate removal by photosynthetic bacteria. After using of Rhodospillum rubrum KS-301 and IFO 3986, which are photosynthetic bacteria as strains, R. rubrum KS-301 was turned out a better strain. And result of experiment in which glucose and sodium lactate, components of wastewater, were used limiting substrates, showed that the productivity of hydrogen was indifferent with the kind of substrates. In batch experiments using free cells and immobilized whole cells, the decrease in hydrogen productivity was observed in the latter case. From the results of these experiments, specific growth rate of cells, specific utilization rate of glucose, and specific production rate of hydrogen were calculated. And each rate was expressed in the form of Monod equation of which parameters were estimated. Also the optimum condition of hydrogen production for free cells was $30^{\circ}C$, pH 7, and 12,000 Lux, and the optimum immobilized condition was as follows: initial immobilized cell concentration 1.0g/L, sodium alginate concentration 2% and light intensity 12,000 Lux.

• 아시안잔디학회지
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• 제3권1호
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• pp.24-33
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• 1989

This study was conducted to investigate the effect of paclobutrazol [(2 RS , 3 RS )1-(4- chlor-ophenyl )-4, 4- dimethyl -2- (1, 2, 4- triazol -1- yl )- pentan -3-01] on the tolerance of hi-gh temperature and drought stress as related to growth retardation , iranspiration rate , soil water content , nitrogen level and photosynthetic rate in perennial ryegrass ( Loliurn perenne L . ' Omega H , ). Plants were given a 30 ml soil drench of paclohutrazol at the concentrations of 0, 0.01, 0.1, 1.0, 10.. 0, mg / 6 .5cm- diameter pot . The rcsults were as follows : 1. Increasing concentrations of paclohutrazul reduced plant height , leaf area , fresh weight and dry weight , hut increased chlorophyll content per unit area . The number of tillers and leaf width were not affected hy the paclobutrazol concentrations . 2. The proper concentration of paclohatrazol on growth retardation in perennial ryegrass was about I mq /pot , hut leaf deformity and severe growth retardation were shown at high concentration of 10 mq / pot . 3. Perennial ryegrasses grown at 30˚C were shown significantly short plant height and low leaf nitrogen level compared with those grown at 20˚C. Increasing concentrations of paclohutrazol at 20˚C increased nitrogen level hut it could not increase nitrogen level at 30˚C . 4. During the drought stress , increasing temperatures significantly promoted transpiration rate and wilting time . It took about 5 days at 20˚C and 3 days at 30˚C to reach wilting time of leaves from water stress treatment . Soil water contents at wilting time of non-treated controls were averaged 6. 871% at 20˚C and 6. 17% at 30˚C 5. Paclohutrazol reduced transpiration rate at high temperature and drought stress . Wilting appeared at the lower water content of soil according to increasing concentrations of paclobutrazol at 30˚C hut there were no differences among concentrations of at 20˚C. 6.Paclohutrazol treatment at 1 rag /pot reduced injury rate of leaves from 67.1 % and 100 % in control plants to 15.7% and 80% at 20˚C and 3010, respectively. 7. Photosynthetic rate per unit area was significantly reduced at high temperature . Paclohutrazol stimulated photosynthetic rate with increase of concentrations at 20˚C but there was no increasing effect at 30˚C.

• 한국조경학회지
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• 제29권6호
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• pp.92-100
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• 2002

This study was carried out to obtain fundamental information on the growth response of interior landscape plants under fluorescent light, sunlight and optical fiber lighting indoors. Saintpaulia ‘Delaware’, ‘Kalanchoe blossfeldiana, Anthurium scherzerianum and Ardisia crenata were examined using light intensity of 5001ux and 1,0001ux of fluorescent light, sunlight and optical fiber lighting in an interior environment. Results of experiments are as follows; 1) Plant growth status showed the best results under optical fiber lighting compared with fluorescent light or sunlight. 2) Plant growth status was better under 1,0001ux light intensity than 5001ux light intensity and in cases of the same light intensity, the highest growth increase was under optical fiber lighting. while it was showed relatively different according to the different plant species between a fluorescent light and sunlight. 3) The deep pinkish red color of Saintpaulia ‘Delaware’flower was obtained first under an optical fiber lighting and a fluorescent light, a sun light in that order. 4) Regarding interred activity, photosynthetic rate and transpiration rate, intercellular CO, water absorption rate showed a similar tendency generally in spite of a little difference. Namely, transpiration rate and intercellular CO, $CO_2$ a absorption rate increased according to increase of photosynthetic rate. 5) Photosynthetic rate of test plants except Anthurium scherzerianum increased according to increase of light intensity and increased highest under optical fiber lighting in the same light intensity condition. Increases differed under fluorescent light and sun light. That of Saineaulia ‘Delaware’and Anthurium scherzerianum increased in the order of optical fiber, fluorescent light and sun light, but that of Kalanchoe blossfeldiana and Ardisia pusilla increased in the order of optical fiber lighting, sun light and fluorescent light. Summing up these results, In visual value or internal health status of all experimental plants we obtained the highest result under an optical fiber lighting. Finally, we need to introduce an optical fiber lighting in interior landscape space as main light source.

• 한국농림기상학회지
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• 제7권3호
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• pp.220-226
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• 2005

오존 노출이 버즘나무의 광합성 특성에 미치는 영향을 조사하기 위하여, 2년생 버즘나무 유묘에 하루에 8시간씩 100 ppb의 오존을 처리하였다. 오존 처리를 진행하는 동안, 3주마다 버즘나무의 엽내 엽록소 함량과 광합성 특성을 측정하였다. 오존에 의한 잎의 가시적 피해는 나타나지 않았으며, 또한 엽내 엽록소 함량은 대조구와 뚜렷한 차이를 보이지 않았다. 그러나 광합성량, 기공전도도, 수분이용효율은 오존 처리 6주 후에 대조구보다 감소하였다. 한편 탄소고정효율과 광화학 효율은 오존 처리 3주와 6주 후에서 감소한 것으로 나타났다. 위의 결과를 토대로 볼 때, 탄소고정효율은 오존 스트레스에 가장 민감한 파라미터로 나타났으며, 이것은 오존 민감성을 평가하기 위한 매우 적당한 지표로 생각되었다.

• 한국작물학회지
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• 제38권2호
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• pp.121-127
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• 1993

보리의 식물체를 등열중기에 가축의 조사료로 급여하기에 적당한 총체형 보리 (barlet for whole crop forage)로 까락이 없고 생체중이 큰 초형이 필요한데, 망장, 동질유전자계(망장, 무망)를 선발하여 두 계통의 수량성 및 그 구성요소의 차이를 비료하고, 지엽 및 까락의 절제가 광합성능과 수량성에 미치는 영향을 조사하였다. 1. v장 추파한 무망종의 간장, 수장, 1수입수, 엽면적, 광합성능 및 생체중이 장망종에 비해서 컸으나 수량성은 6%정도 적었다. 2. 지엽 또는 까락을 절제시, 천입중과 곡입중의 감소를 초래하였는데, 천입중과 곡입중은 지엽절제시 3～4%와 5～6%가 각각 감소되었고, 장망의 까락 절제시 천입중과 곡입중은 7%와 15%가 가각 감소되었다. 지엽 및 까락을 동시에 절제시는 14%와 21%가 감소되었다. 3. 지엽의 광합성능은 차엽신 및 제3엽신 보다 7～8%와 37～41%가 각각 높았다. 무망종의 엽위별 엽신의 평균 광합성능은 6.1～9.7 co$_2$$_2$ ${\mu}$mole $m^{-2}$ $s{-1}$, 로 장망종 보다 매우 높았다. 4. 본 관험에서 공시된 무망종은 장망종에 비하여 엽신의 광합성능이 크고, 줄기 및 엽초의 생체중이 커서 총생체중이 무거워 총체형 사료(whole crop forage)이 초형으로 적당한 계통이라고 생각된다.

• 한국기후변화학회지
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• 제7권1호
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• pp.77-84
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• 2016

Seedling stage is particularly important for tree survival and is easily influenced by warming. Therefore, air temperature being increased due to climate change may affect physiological traits and growth of seedlings. This study was conducted to investigate the physiological and growth responses of Larix kaempferi seedlings to open-field experimental warming. 1-year-old and 2-year-old L. kaempferi seedlings were warmed with infrared lamps since April 2015 and April 2014, respectively. The seedlings in the warmed plots were warmed to maintain the air temperature to be $3^{\circ}C$ higher than that of the control plots. Physiological responses (stomatal conductance, transpiration rate, net photosynthetic rate and total chlorophyll content) and growth responses (root collar diameter (RCD), height and biomass) to experimental warming were measured. Physiological and growth responses varied with the seedling ages. For 2-year-old L. kaempferi seedlings, stomatal conductance, transpiration rate and net photosynthetic rate decreased following the warming treatment, whereas there were no changes for 1-year-old L. kaempferi seedlings. Meanwhile, total chlorophyll content was higher in warmed plots regardless of the seedling ages. Net photosynthetic rate linked with stomatal conductance also decreased due to the drought stress and decrease of photosynthetic efficiency. In response to warming, RCD, height and biomass did not show significant differences between the treatments. It seems that the growth responses were not affected as much as physiological responses were, since the physiological responses were not consistent, nor the warming treatment period was enough to have significant results. In addition, multifactorial experiments considering the impact of decreased soil moisture resulting from elevated temperatures is needed to explicate the impacts of a wide range of possible climate change scenarios.

• 생물환경조절학회지
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• 제10권3호
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• pp.159-164
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• 2001

겨울철 시설내에서 정전 등으로 인하여 수시간 동안 작물체가 생육한계 온도로 경과시 이오묘에 나타나는 피해와 피해발생의 생리적 요인 및 경감대책을 구명하기 위하여 저온 스트레스가 이이묘의 광합성 및 생리반응에 미치는 영향을 연구한 결과는 다음과 같다. 냉온처리($0^{\circ}C$)는 무처리에 비한 오이묘의 광합성량이 10시간 처리는 52.8%, 24시간 처리에서는 67.6% 감소시켰으나, 5시간처리는 무처리와 큰 차이가 없었다. 냉온처리 기간중의(3$^{\circ}C$, 15시간)광조사는 암상태에서 보다 광합성을 크게 저해시켰다. 냉온처리 후 회복기간 중에 암조건을 주면 광합성량이 다소 회복되었으나 광조사시에는 회복되지 못하였다. 0~6$^{\circ}C$ 범위내의 냉온처리는 무처리에 비해 뿌리활력을 유의하게 감소시켰고, 냉온처리 40일후 채취된 오이줄기의 일비액량은 처리간 유의차를 보이지 않았다. 냉온처리(3$^{\circ}C$)시 전당 함량은 무처리에 비해 24시간 처리에서는 12%, 48시간 처리에서는 23% 증가되었다. 한편 냉온처리에 의하여, 불포화지방산인 linolenic acid와 oleic acid는 증가되었으나, 포화지방산인 palmitic acid는 감소되었다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제1권1호
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• pp.51-59
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• 1997

Two comparative poplar clones (I-214: Populus euramericana, Peace: P koreana x P. trichocarpa) were exposed to two $CO_2$ concentrations (350 or 2,000 ${\mu}L\;L^{-1}\;CO_2)$ for 21 days. When both poplar clones were compared at growth conditions, the net photosynthetic rate $(P_N)$ in $CO_2-enriched$ (2,000 ${\mu}L\;L^{-1}\;CO_2=C_{2,000})$ plants become about $50-60\%$ higher than that of 350 ${\mu}L\;L^{-1}\;CO_2(=C_{350})$ plants on 7 days treatment. But the enhancement of $P_N$ by high $CO_2$ was not maintained throughout all the experimental period. At 21 days, there was no difference of photosynthetic rates between $C_{350}\;and\;C_{2,000}$ plants. In contrast with photosynthesis, the response of leaf conductance to the elevated $CO_2$ concentration was very different between I-214 and Peace. During all experimental period, leaf conductance $(g_s)$ of $C_{2,000}$ plants is $50\%$ lower than that of the $C_{350}$ plants for I-214, while there is no difference of $g_s$ between the plants of $C_{350}\;and\;C_{2,000}$ on for Peace. The results of gs in Peace indicate that decreased photosynthetic rate after 21 days in $C_{2,000}$ on plants for two poplar clones is possibly due to non-stomatal factors. To investigate the non-stomatal factors, starch accumulation and ribulose-1,6-bisphosphate carboxylase (RuBPCase) were measured. We found significant accumulation of starch in two poplar clones exposed to high $CO_2,$ especially starch of I-214 in $C_{2,000}$ become 3.5 times higher than in $C_{350}$ plants at 21 days. This suggests that high proportion of photosynthates was directed into starch. After 21 days, the activity of ribulose-1, 6-bisphosphate carboxylase of $C_{2,000}$ plants become decreased in $40-50\%$ compared with that of the $C_{350}$ plants. Two poplar clones show the same trend to RuBPCase declines under high $CO_2$ concentration, although the decline is more significant for I-214. The results reported here suggest that starch accumulation and decreased RuBPCase activity in $C_{2,000}$ plants can be partly ascribed to the loss of photosynthetic efficiency of high $CO_2-grown$ poplar plants.

• 한국환경과학회지
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• 제1권1호
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• pp.51-59
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• 1992

Two comparative poplar clones (I-214: Populus euramerinm, Peace: P koreana x p. trihocarpa) were exposed to two $CO_2$ concentrations (350 or 2, 000 ${\mu}L L^{-1} CO_2$) for 21 days. When both poplar clones were compared at growth conditions, the net photosynthetic rate ($P_N$) in $CO_2$-enriched ($2, 000{\mu}L L^{-1} CO_2 = C_{2, 000}$) plants become about 50-60% higher than that of 350 ${\mu}L L^{-1} CO_2 (=C_{350}$ Plants on 7 days treatment. But the enhancement of PN by high $CO_2$ was not maintained throughout all the experimental period. At 21 days, there was no difference of photosynthetic rates between $C_{350}$ and $C_{2000}$ plants. In contrast with photosynthesis, the response of leaf conductance to the elevated $CO_2$ concentration was very different between I-214 and Peace. During all experimental period, leaf conductance ($g_{s}$) of $C_{2000}$ plants is 50% lower than that of the $C_{350}$ plants for I-214, while there is no difference of gs between the plants of $C_{350}$ and $C_{2, 000}$ for Peace. The results of gs in Peace indicate that decreased photosynthetic rate after 21 days in $C_{2, 000}$ Plants for two poplar clones is possibly due to non-stomatal factors. To investigate the non-stomatal factors, starch accumulation and ribulose-1, 6-bisphosphate carboxylase (RuBPCase) were measured. We found significant accumulation of starch in two poplar clones exposed to high $CO_2$, especially starch of I-214 in $C_{2, 000}$ become 3.5 times higher than in $C_{350}$ plants at 21 days. This suggests that high proportion of photosynthates was directed into starch. After 21 days, the activity of ribulose-1, 6-bisphosphate carboxylase of $C_{2, 000}$ plants become decreased in 40-50% compared with that of the $C_{350}$ plants. Two poplar clones show the same trend to RuBPCase declines under high $CO_2$ concentration, although the decline is more significant for I-214. The results reported here suggest that starch accumulation and decreased RuBPCase activity in $C_{2, 000}$ plants can be partly ascribed to the loss of photosynthetic efficiency of high $CO_2$-grown poplar plants.