• 원예과학기술지
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• 제34권5호
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• pp.708-718
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• 2016

Two different pest control programs were applied on 8-year-old 'Ryoka'/M.26 apple trees (Malus domestica Borkh.). Lime sulfur or Bordeaux mixture with emulsified oil were applied 12 times from late March to mid-September as organic treatment, and synthetic chemicals were 7 times applied as control treatment. Over the entire apple-growing season, photosynthesis rates of apple trees were significantly lower in the organic treatment than in the control, and this photosynthetic differences were larger in July and August. Photosynthesis-related parameters such as stomatal conductance and transpiration behaved similarly to photosynthesis. The leaf area in the organic treatment was significantly smaller ($24.7cm^2$) than that in the control treatment ($30.7cm^2$). Organic leaves contained significantly less Chl. a ($15.5mg{\cdot}g^{-1}$) than did control leaves ($17.6mg{\cdot}g^{-1}$). Fruit yield per tree was significantly lower in the organic treatment (18.8 kg) than in the control (24.5 kg), because organic fruits experienced a higher rate of disease infection such as white rot (Botryosphaeria dothidae) and bitter rot (Glomerella cingulata) than did control fruits. Organic fruits had high flesh firmness but less color development (lower Hunter's a values). In this experiment, the pest control program with frequent applications of organic fungicides showed negative effects on photosynthesis and disease infection on leaves and fruits, and thus reduce the fruit quality and yield in 'Ryoka'/M.26 apple trees.

• Plant Biotechnology Reports
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• 제4권3호
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• pp.213-222
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• 2010

Within their natural habitat, crops are often subjected to drought and heat stress, which suppress crop growth and decrease crop production. Causing overaccumulation of glycinebetaine (GB) has been used to enhance the crop yield under stress. Here, we investigated the response of wheat (Triticum aestivum L.) photosynthesis to drought, heat stress and their combination with a transgenic wheat line (T6) overaccumulating GB and its wild-type (WT) Shi4185. Drought stress (DS) was imposed by controlling irrigation until the relative water content (RWC) of the flag leaves decreased to between 78 and 82%. Heat stress (HS) was applied by exposing wheat plants to $40^{\circ}C$ for 4 h. A combination of drought and heat stress was applied by subjecting the drought-stressed plants to a heat stress as above. The results indicated that all stresses decreased photosynthesis, but the combination of drought and heat stress exacerbated the negative effects on photosynthesis more than exposure to drought or heat stress alone. Drought stress decreased the transpiration rate (Tr), stomatal conductance (Gs) and intercellular $CO_2$ concentration (Ci), while heat stress increased all of these; the deprivation of water was greater under drought stress than heat stress, but heat stress decreased the antioxidant enzyme activity to a greater extent. Overaccumulated GB could alleviate the decrease of photosynthesis caused by all stresses tested. These suggest that GB induces an increase of osmotic adjustments for drought tolerance, while its improvement of the antioxidative defense system including antioxidative enzymes and antioxidants may be more important for heat tolerance.

• ALGAE
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• 제31권1호
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• pp.49-59
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• 2016

Ulva pertusa, a common bloom-forming green alga, was used as a model system to examine the effects of elevated carbon dioxide (CO₂) and temperature on growth and photosynthetic performance. To do this, U. pertusa was grown under four temperature and CO₂ conditions; ambient CO₂ (400 μatm) and temperature (16℃) (i.e., present), elevated temperature only (19℃) (ET; i.e., warming), elevated CO₂ only (1,000 μatm) (EC; i.e., acidification), and elevated temperature and CO₂ (ET and EC; i.e., greenhouse), and its steady state photosynthetic performance evaluated. Maximum gross photosynthetic rates (GP_max) were highest under EC conditions and lowest under ET conditions. Further, ET conditions resulted in decreased rate of dark respiration (R_d), but growth of U. pertusa was higher under ET conditions than under ambient temperature conditions. In order to evaluate external carbonic anhydrase (eCA) activity, photosynthesis was measured at 70 μmol photons m⁻² s⁻¹ in the presence or absence of the eCA inhibitor acetazolamide (AZ), which inhibited photosynthetic rates in all treatments, indicating eCA activity. However, while AZ reduced U. pertusa photosynthesis in all treatments, this reduction was lower under ambient CO₂ conditions (both present and warming) compared to EC conditions (both acidification and greenhouse). Moreover, Chlorophyll a and glucose contents in U. pertusa tissues declined under ET conditions (both warming and greenhouse) in conjunction with reduced GP_max and R_d. Overall, our results indicate that the interaction of EC and ET would offset each other’s impacts on photosynthesis and biochemical composition as related to carbon balance of U. pertusa.

• 한국농림기상학회지
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• 제1권1호
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• pp.52-59
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• 1999

Vegetation canopy plays an important role in $CO_2$/$H_2$O exchange between the biosphere and the atmosphere by controlling leaf stomata. In this study, rice (Oryza sativa L.), a staple crop in Asia was investigated to formulate its single leaf model of photosynthesis and stomatal conductance. Photosynthesis and stomatal conductance were measured with a portable infrared gas analyzer system. Other plant and meteorological variables were also measured. To evaluate empirical constants in this biochemical leaf model, nonlinear least squares technique was used. The maximum catalytic activity of enzyme and the maximum rate of electron transport were $ 100\mu$㏖ $m^{-2}$ $s^{-1}$ and $140 \mu$㏖ m$^{-2}$ s$^{-1}$ (@ 35$^{\circ}C$), respectively. The empirical constants, m and b, associated with stomatal conductance model were 9.7 and $0.06 m^{-2}$ $s^{-1}$ , respectively. On a leaf scale, agreements between the modeled and the measured values of photosynthesis and stomatal conductance were on average within 20%, and the simulation of diurnal variation was also satisfactory On a canopy scale, the Simple Biosphere model(SiB2) was tested using the derived parameters. The modeled energy fluxes were compared against the micrometeorologically measured fluxes over a rice canopy. Agreements between the modeled and the measured values of net radiation, sensible heat and latent heat fluxes, and $CO_2$ flux (i.e., net canopy photosynthesis) were on average within 25%.

• The Plant Pathology Journal
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• 제35권5호
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• pp.521-529
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• 2019

Tomato yellow leaf curl China virus is a species of the widespread geminiviruses. The infection of Nicotiana benthamiana by Tomato yellow leaf curl China virus (TYLCCNV) causes a reduction in photosynthetic activity, which is part of the viral symptoms. ${\beta}C1$ is a viral factor encoded by the betasatellite DNA ($DNA{\beta}$) accompanying TYLCCNV. It is a major viral pathogenicity factor of TYLCCNV. To elucidate the effect of ${\beta}C1$ on plants' photosynthesis, we measured the relative chlorophyll (Chl) content and Chl fluorescence in TY-LCCNV-infected and ${\beta}C1$ transgenic N. benthamiana plants. The results showed that Chl content is reduced in TYLCCNV A-infected, TYLCCNV A plus $DNA{\beta}$ (TYLCCNV A + ${\beta}$)-infected and ${\beta}C1$ transgenic plants. Further, changes in Chl fluorescence parameters, such as electron transport rate, $F_v/F_m$, NPQ, and qP, revealed that photosynthetic efficiency is compromised in the aforementioned N. benthamiana plants. The presense of ${\beta}C1$ aggravated the decrease of Chl content and photosynthetic efficiency during viral infection. Additionally, the real-time quantitative PCR analysis of oxygen evolving complex genes in photosystem II, such as PsbO, PsbP, PsbQ, and PsbR, showed a significant reduction of the relative expression of these genes at the late stage of TYLCCNV A + ${\beta}$ infection and at the vegetative stage of ${\beta}C1$ transgenic N. benthamiana plants. In summary, this study revealed the pathogenicity of TYLCCNV in photosynthesis and disclosed the effect of ${\beta}C1$ in exacerbating the damage in photosynthesis efficiency by TYLCCNV infection.

• Journal of Plant Biotechnology
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• 제50권
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• pp.127-136
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• 2023

Water scarcity decreases the rate of photosynthesis and, consequently, the yield of banana plants (Musa spp). In this study, transcriptome analysis was performed to identify photosynthesis-related genes in banana plants and determine their expression profiles under water stress conditions. Banana plantlets were in vitro cultured on Murashige and Skoog agar medium with and without 10% polyethylene glycol and marked as BP10 and BK. Chlorophyll contents in the plant shoots were determined spectrophotometrically. Two cDNA libraries generated from BK and BP10 plantlets, respectively, were used as the reference for transcriptome data. Gene ontology (GO) enrichment analysis was performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) and visualized using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway prediction. Morphological observations indicated that water deficiency caused chlorosis and reduced the shoot chlorophyll content of banana plantlets. GO enrichment identified 52 photosynthesis-related genes that were affected by water stress. KEGG visualization revealed the pathways related to the 52 photosynthesisr-elated genes and their allocations in four GO terms. Four, 12, 15, and 21 genes were related to chlorophyll biosynthesis, the Calvin cycle, the photosynthetic electron transfer chain, and the light-harvesting complex, respectively. Differentially expressed gene (DEG) analysis using DESeq revealed that 45 genes were down-regulated, whereas seven genes were up-regulated. Four of the down-regulated genes were responsible for chlorophyll biosynthesis and appeared to cause the decrease in the banana leaf chlorophyll content. Among the annotated DEGs, MaPNDO, MaPSAL, and MaFEDA were selected and validated using quantitative real-time PCR.

• 한국수산과학회지
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• 제16권4호
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• pp.335-340
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• 1983

양식 김에 미치는 수온, 염분 및 해수중의 현탁부니의 영향을 조사하였다. 1. 김의 광합성률은 실험수온 $8{\sim}16^{\circ}C$까지는 수온이 높아짐에 따라 증가하였으나 $18^{\circ}C$에서는 감소되었다. 2. 실험염분 $21.5{\sim}33.5\%0$ 범위에서, 김의 광합성률은 $29.5\%0$에서 다소 증가하였고 $21.5\%0$에서는 감소하였다. 3. 김의 광합성률은 부니의 농도가 증가함에 따라 또 처리일수가 경과함에 따라 현저히 감소하였다. 4. 김의 광합성률에 미치는 염분과 부니의 복합영향을 보면, 저염분영향이 큰 $21.5\%0$에서 부니의 영향이 컸고, $33.5\%0$에서도 비슷한 경향을 보였다. 5. 김의 생체량은 부니의 농도가 증가함에 따라 또 처리일수가 경과함에 따라 현저히 감소하였다.

• 한국산림과학회지
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• 제63권1호
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• pp.42-50
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• 1984

리기다소나무와 리기테다소나무의 유시(幼時) 및 가계간(家系間)의 생장능력(生長能力)을 예측(豫測)하기 위하여 2년생(年生) 묘목(苗木)을 대상(對象)으로 생장(生長), 광합성능력(光合成能力) 그리고 순동화율(純同化率)을 조사(調査) 비교(比較)하였다. 리기다소나무와 리기테다소나무 모두 순동화율(純同化率)과 광합성능력(光合成能力)의 유전적(遺傳的) 변이(變異)를 볼 수 있었으며, 리기다소나무 3가계(家系)를 제외한 다른 모든 가계(家系)의 광합성능력(光合成能力)은 생장(生長)함에 따라 감소(減少)하는 경향(傾向)을 보였으며 순동화율(純同化率)은 모든 가계(家系)가 감소(減少)하였다. 모든 가계(家系)의 광합성능력(光合成能力)과 순동화율(純同化率)의 순서가 실험기간(實驗期間) 동안 일정하지 않아 어느 한 시기(時期)의 측정치(測定値)로 평가(評價)할 수 없으므로 총광합성(總光合成) 능력(能力)과 총순동화율(總純同化率)로 평가(評價)하였다. 총광합성능력(總光合成能力)과 총순동화율(總純同化率)은 총건중량(總乾重量)과 각각(各各) 0.6394, 0.7998의 상관(相關)을 나타냈다. 따라서 양수종(兩樹種)의 생장력(生長力)은 총광합성능력(總光合成能力)과 총순동화율(總純同化率)의 측정(測定)에 의해 예측(豫測)할 수 있었다. 리기테다소나무의 가계(家系) 경기(京畿) 13호(號) ${\times}7-107$과 리기다소나무의 가계(家系) 경기(京畿) 1호(號)가 수종내(樹種內)에서 가장 우수한 생장능력(生長能力)을 나타냈다.

• 한국약용작물학회지
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• 제2권1호
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• pp.86-94
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• 1994

인삼(人蔘)의 광합성(光合成)이 콩보다 낮은 원인(原因)을 밝혀 인삼(人蔘)의 수량증대(收量增大)와 육종(育種)을 위한 기초자료(基礎資料)로 삼고저 자경종(紫莖種) 2년생(年生) 인삼식물(人蔘植物)에서 분리(分離)한 잎을 재료(材料)로 광합성(光合成)과 수분함량(水分含量), 기공식도도(氣孔植導度), 그리고 수분(水分) potential을 조사(調査)하고 콩과 비교(比較)하였다. 1. 동일(同一)한 광도(光度)에서 광합성(光合成)은 인삼(人蔘)이 콩보다 작았으며 광합성(光合成)에 대한 포화광도(飽和光度)도 약 $30{\mu}E\;/\;m^2\;/\;s$로 콩의 약 $800{\mu}E\;/\;m^2\;/\;s$보다 낮았다. 2. 분리(分離)한 잎에서 광합성(光合成)은 인삼(人蔘)이 콩보다 빠르게 감소(減少)하였으며 $20^{\circ}C$에서보다 $30^{\circ}C$에서 더 빨랐다. 또한 광합성(光合成)이 정지(停止)하는 시간(時間)도 인삼(人蔘)잎이 콩잎보다, $20^{\circ}C$에서보다 $30^{\circ}C$에서 더 짧았다. 3. 잎의 수분감소(水分減少速度)는 인삼(人蔘)이 콩보다 느렸고 광합성(光合成)이 정지(停止)되는 수분함량(水分含量)은 인삼(人蔘)잎(약$70{\sim}71%$)이 콩잎$(50{\sim}63%)$보다 높았다. 4. 수분함량(水分含量)파 광합성(光合成)과는 인삼(人蔘)과 콩 모두 온도(溫度)에 무관(無關)하게 각각(各各) 고도(高度)의 정(正)의 상관(相關)이 있었는데, 광합성(光合成)은 동일(同一)한 수분함량(水分含量)에서 인삼(人蔘)이 콩보다작았다. 5. 기공식도도(氣孔傳導度)와 광합성(光合成)과는 인삼(人蔘)과 콩 모두 두 온도(溫度)$(20^{\circ}C,\;30^{\circ}C)$에서 무관(無關)하게 고도(高度)의 정(正)의 상관(相關)이 있었으며, $20^{\circ}C$에서는 인삼(人蔘)의 기공식도도(氣孔傳導度) 범위(範圍)$(40mmo1\;/\;m^2\;이하)$에서 인삼(人蔘)과 콩의 광합성양(光合成量)은 비슷하였다. 6. 수분(水分) potential 엽수분함량(葉水分含量)이 동일(同一)한 조건(條件)에서 콩보다 인삼(人蔘)이 낮았으며, 수분(水分) potential과 광합성(光合成) 및 기공식도도(氣孔傳導度)와는 고도(高度)의 정(正)의 상관(相關)이있었다. 7. 이상(以上)의 결과(結果)를 종합(綜合)해 볼 때, 인삼(人蔘)의 광합성(光合成)이 타식물(他植物)보다 낮은 것은 기공식도도(氣孔傳導度)와 수분(水分) potential이 낮은 것과도 밀접(密接)한 관계(關係)가 있을 것으로 생각된다.

• 한국작물학회지
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• 제60권3호
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• pp.266-272
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• 2015

등숙기 고온이 잎의 생리적 활력과 등숙에 미치는 영향을 알아보고자, 동안과 일품 두 품종을 등숙기에 고온 처리하여 등숙 형질을 분석하고, 잎의 광합성, 엽록소 함량 및 엽록소 a/b율 등을 알아보았다. 등숙기 고온($27{\pm}4^{\circ}C$)처리에서 두 품종 모두 등숙률, 완전립률, 천립중이 감소하였으나 일품은 동안에 비해 모두 감소율이 컸다. 엽록소 함량은 등숙초기 고온에서 적온보다 두 품종 모두 증가하였으며, 등숙중기이후 엽록소감소양상은 온도처리에 따른 차이가 없었다. 엽록소 a/b율은 고온에서 감소하였다가 출수후 15일 이후 증가하였으며 적온에서는 출수 이후 지속적으로 증가하였다. 잎의 단백질농도 변화는 고온에서 등숙초기 약간 높은 경향이었으나 이후 처리 간 차이없이 등숙후기까지 지속적으로 감소하였다. 최대 광합성량은 유숙기인 출수 후 14일에 고온이 적온보다 높았고 출수후 7일과, 등숙후기(출수후 34일)에는 유의한 차이가 없었다. 잎의 유리당 함량은 고온이 적온보다 낮았다. 결론적으로 등숙기 고온은 잎의 생리적 활력을 적온보다 오히려 증가 시켜 엽록소함량과 광합성율이 증가하였으므로, 고온에 의한 이삭의 등숙저하는 이삭으로의 전류나 전분축적기작 과정의 문제가 더 클 것으로 생각된다.