To compare the vitality among cool-season turfgrasses under summer weather conditions and to obtain information to improve the management of turfgrasses in golf courses and sports fields., the chlorophyll fluorescence of three cool-season turfgrasses commonly planted on golf courses in the Jeju area was measured. The turfgrasses were perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), and creeping bentgrass (Agrostis palustris Huds.). In perennial ryegrass and Kentucky bluegrass, the chlorophyll index was low in early summer and high in late summer. In creeping bentgrass, it remained low throughout the study. Fo tended to be low in the early summer and high in late summer in the three turfgrasses. However, the difference in Fo between late summer and early summer was markedly higher in perennial ryegrass than in Kentucky bluegrass or creeping bentgrass. Fm tended to be low in early summer and high in late summer, without obvious differences among the three turfgrasses. Fv/Fm, a measure of photochemical efficiency, was also low in early summer and high in late summer in the three turfgrasses. However, Fv/Fm in late summer was mostly higher in Kentucky bluegrass and creeping bentgrass than in perennial ryegrass, indicating that the former are more resistant to the high temperature and humidity of late summer. Furthermore, Kentucky bluegrass had a high chlorophyll index in late summer and would be most resistant to the harsh conditions of late summer.

Background : The chlorophyll fluorescence imaging as non-destructive imaging methods have been used widely for efficiently early detection of plant responses to various stresses. The information from images acquired from different condition has the potential to generate specific signatures for particular stresses. Light-energy absorbed by plants is distributed over three competing processes: photosynthesis, thermal dissipation and chlorophyll fluorescence emission. An increase in Chl-FI thus implies a decrease in photosynthesis. The stresses in growing stage will change the efficacy of photosynthesis. As a example, Chl-FI of plant infections was carried out previously for a number of different viral and fungal plant–pathogen systems. Therefore, image can be used for differentiation of various stress index. Methods and results : 2-years-old ginseng plants were transplanted to plastic pots and each stress factors were treated. The stress factors used in this study were high temperature, low temperature, fungicide, and fungal pathogen. High temperature stress was induced by placing pots inside incubator adjusted at 35℃. For treatment of low temperature stress, ginseng plants were stored at 5℃ refrigerator for 5 minutes. Pathogen stress was carried to inoculate mycelial disk. Alternaria panax was inoculated potato-dextrose-medium and cultured for 10 days at 25℃. Mycelial disk obtained from cultured plate were placed on the one leaf of ginseng. Azoxystrobin wp was diluted 500, 1,000 times in tap water and sprayed to ginseng plants. Chlorophyll fluorescence image was acquired from each plant that stress treated and analyzed with sigma plot software. Conclusion : Important value, Fv/Fm (maximum efficiency of photosystem II), Fp (peak fluorescence during the initial phase of the operating efficiency of the Kautsky effect), NPQ-lss (steady-state, non-photochemical), etc., were significantly changed by variable stress index. But it was impossible to differentiate kind of stress by acquired value.

재배지 부족과 기후변화로 인하여 인삼재배의 생산량이 적 어지고 있어 추가적인 방법이 필요하다. 따라서 기존에는 환경 산업 및 식품포장, 가공에 활용되고 있는 파인버블을 우리나라 대표 작물인 인삼재배에 적용하여 변화되는 생리적, 형태적 특성을 분석하였다. 2년 근 인삼에 파인버블수를 적용한 결과 Table 2에서 보듯이 줄기 길이와 잎이 증가되었고 뿌리에서는 주근이 커지면서 무게가 증가되었다. 특히 잎이 커지면서 뿌리의 무게가 증가됨을 보이고 있는데 이는 총 엽록소 함량을 확인한 결과 높게 나와 광합성 효율 증대와 연계되었다고 판단된다. 본 연구결과에서는 파인버블수를 사용한 인삼 재배시 인삼의 성장 저해가 나타나지 않았음을 확인하였으며, 생리적 특성 및 세분화된 결과를 통해 인삼의 전체적인 생육이 약 10%에서 15% 생장이 증가되는 것을 확인할 수가 있다. 따라서 인삼 재배시 파인버블수를 적용함으로써 인삼이 생육 증대가 이루어지고 있다는 것을 의미할 수 있다. 추후 파인 버블수를 적용된 3-5년 근의 고년 근 인삼에서도 특징을 유지하는지 추가적인 연구가 필요하다고 사료된다.

Background : Management of air temperature are known to primarily affecting on physiological properties and yield in plant. Methods and Results : The effect of air temperature on characteristics of photosynthesis and chlorophyll fluorescence in Cnidium officinal were investigated using growth chamber after cultivating for 24 hours under controlled condition. Net photosyntheis rate, transpiration was measured at 1,000 μmol m-2 s-1 of photon flux density and chlorophyll fluorescence was analyzed by OJIP method. Net photosyntheis rate was highest in treatment of 25℃. Although transpiration rate was lowest, water use efficience was also in treatment of 25℃. Stomatal conductance was mainly influenced from ambient climatric factors such as vapor pressure deficit. As results of chlorophyll fluorescence by OJIP analysis, maximum quantum yield (Fv/Fm) of photosystem II (PSII), PIabs and the relative activities per reaction center such as ABS/RC, DIo/RC were not changed at air temperature. Therefore, elevated air temperatue during short term influence the dark reaction in photosystem through controlling a water use efficience and transpiration. Conclusion : This result show that 25℃ of air temperature may be a adequate temperature to improving the efficiency of photosynthesis in Cnidium officinale.

The objective of this study was to find a rapid determination of the hot air stress in maize (Zea mays L.) leaves using a portable chlorophyll fluorescence imaging instrument. To assess the photosynthetic activity of maize leaves, an imaging analysis of the photochemical responses of maize was performed with chlorophyll fluorescence camera. The observed chlorophyll imaging photos were numerically transformed to the photochemical parameters on the basis of chlorophyll a fluorescence. Chlorophyll a fluorescence imaging (CFI) method showed that a rapid decrease in maximum fluorescence intensity (Fm) of leaf occurred under hot air stress. Although no change was observed in the maximum quantum yield (Fv/Fm) of the hot air stressed maize leaves, the other photochemical parameters such as maximum fluorescence intensity (Fm) and Maximum fluorescence value (Fp) were relatively lowered after hot air stress. In hot air stressed maize leaves, an increase was observed in the nonphotoquenching (NPQ) and decrease in the effective quantum yield of photochemical energy conversion in photosystem II (Φ PSII). Thus, NPQ and ΦPSII were available to be determined non-destructively in maize leaves under hot air stress. Our results clearly indicated that the hot air could be a source of stress in maize leaves. Thus, the CFI analysis along with its related parameters can be used as a rapid indicating technique for the determining hot air stress in plants.

Background : The ginseng cool-season and semi-shade plant undergoes photosynthesis smoothly at low temperature in the morning but its efficiency falls at high temperature in the afternoon. Therefore, if it is possible to control light transmission rates (LTR) every day, it will be able to draw an ideal result in the ginseng growth by attracting a lot of lights before 11am and attracting few lights after 11am which is the affect point of the photosynthetic efficiency. Methods and Results : While installing the sun shading facility that could control the light environment based on 11am and surveying the ginseng's growth and photosynthetic characteristics. The photosynthetic efficiency increased 2.81 times compared to conventional practices without the change of the chlorophyll content although LTR was high because of the low temperature in the morning. The aboveground part growth of the ginseng which adapted to the light environment increased to influence the root weight, when the ginseng was 4 years old, the fresh root weight was averagely 33.3g per plant which increased by 81% than 18.4g of conventional practices. Conclusion : If the light environment management according with the photosynthetic nature of the ginseng is conducted based on 11am, it will be possible to produce a large capacity and excellent-quality ginseng.

Background : Management of air temperature are known to primarily affecting on physiological properties and yield in plant. Methods and Results : The effect of air temperature on characteristics of photosynthesis and chlorophyll fluorescence in Schisandra chinensis Baillon were investigated under controlled temperature using growth chamber. Net photosyntheis rate, transpiration was measured at 1,000 μmol m-2 s-1 of photon flux density and chlorophyll fluorescence was analyzed by OJIP method. Net photosyntheis rate and transpiration rate was higher in treatment of 25℃. As results of chlorophyll fluorescence by OJIP analysis, maximum quantum yield (Fv/Fm) of photosystem II (PSII) and PIabs was higher in treatment of 25℃ which reflects the relative reduction state of PSII. But in treatment of 35℃ the relative activities per reaction center such as ABS/RC, DIo/RC were higher than in treatment of 25℃ which implied that the relative reduction of electron transport at PSI and increasement of photo inhibition at reaction center. Conclusion : This result implies that 25℃ of air temperature may be a adequate temperature to improving the efficiency of photosynthesis through controlling a photosystem in Schisandra chinensis Baillon.

This study was conducted to investigate effects of waterlogging on the growth, physiological responses, and yield of Kimchi cabbage. The growth of Kimchi cabbage with applied optimized air temperature (set to 20℃) was greater than those with high air temperature (set to 30℃) and the growth significantly decreased by severe waterlogging treatment. The net photosynthetic rate of outer leaves on one hour after waterlogging treatment was higher at 72 hours waterlogging treatment in 20℃ and lower at 24 hours of waterlogging treatment in 30℃. The root activity was decreased by the elevation of waterlogging periods in 20℃ treatment and lower by the short of waterlogging periods in 30℃ treatment. The ratio of formality with non-waterlogging treatment was approximately 64% under 20℃ air temperature and that of range was from 16 to 30% under 30℃. The yield under 20℃ showed higher than that under high air temperature. The non-waterlogging treatment in 20℃ had 4,463 kg/10a, which was the greatest among all treatments, while yields of non-waterlogging treatment at 30℃ were significantly low as 1,082 kg/10a. Results suggested that additional drainage work should be needed to overcome waterlogged conditions of open field during heavy rainfall and should be drainage as soon as possible if there are waterlogging.

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 μg/mg and 3.83 μg/mg, respectively while the highest carotenoid content was found in MJ ml/L treatment with 1.62 μg/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).

The response of the freshwater microalga, Chlorella vulgaris, to heavy metal stress was examined based on chlorophyll fluorescence analysis to assess the toxic effects of heavy metals in freshwater ecosystems. When toxic effects were analyzed using regular chlorophyll fluorescence analysis, photosystem II activity(Fv/Fm) decreased significantly when exposed to Cu2+ and Hg2+ for 12 h, and decreased in the order of Hg2+ > Cu2+ > Cd2+ > Ni2+ when exposed for 24h. The effective photochemical quantum yield(Φ′PSII), chlorophyll fluorescence decrease ratio(RFd), minimal fluorescence yield(Fo), and non-photochemical quenching(NPQ), but not photochemical quenching(qP), responded sensitively to Hg2+, Cu2+, and Cd2+. These results suggest that Fv/Fm, as well as Φ′PSII, RFd, Fo, and NPQ could be used to assess the effects of heavy metal ions in freshwater ecosystems. However, because many types of heavy metal ions and toxic compounds co-occur under natural conditions, it is difficult to assess heavy metal toxicity in freshwater ecosystems. When Chlorella was exposed to heavy metal ions for 12 or 24h, Fv/Fm and maximal fluorescence yield(Fm) changed in response to Hg2+ and Cu2+ based on image analysis. However, assessing quantitatively the toxic effects of several heavy metal ions is challenging.

Background : Excessively high concentration of sodium ion causednutrient deficiency and significantly decrease growth. This study was carried out to determine the limiting concentration range of sodium ion in the soil of ginseng field. Methods and Results : The growth of the ginseng cultivar Chunpoong reduced with increase in salinity, and the rate of growth reduction was higher in shoots than that of roots. Particularly, ginseng plants cultivated at high level of nitrate nitrogen or sodium may suffer delayed development and stunted growth. Chlorophyll damage occurred on the leaves of ginseng planted in relatively high levels (> 0.2 c㏖+/㎏) of sodium ion, as determined by the fluorescence reaction. The incidence of physiological disorder in ginseng cultivated at 249 sites was correlated with the concentration of sodium ion in the soils. About 74% of ginseng fields in which physiological disorders occurred had concentrations of sodium ion in soil greater than 0.2 c㏖+/㎏. In contrast, the concentration of sodium ions at 51 of 85 sites where no damage occurred was relatively (0.05 c㏖+/㎏- 0.15 c +/㎏). Conclusions : The concentration of sodium ion in soil of ginseng fields can be classified into three levels optimum (≤ 0.15), permissible allowance (0.15 - 0.2) and excessive (> 0.2).

High temperature impairs rice grain yield and quality. To understand the effect of high temperature on leaf physiological activity and grain filling, two cultivars of rice that Dongan and Ilpum were exposed to high temperature during ripening stage. Grain filling rate, perfect grain ratio and grain weight of high temperature (27℃±4℃) treated both rice cultivars were decreased than those of control temperature (22℃±4℃) treated. The reduction rates of grain filling ratio, perfect grain ratio and grain weight of high temperature treated to control treated rice were higher in Ilpum than Dongan. Chlorophyll contents of rice leaves under high temperature at early ripening stage were higher than those of control temperature, but those were slowly decreased with no difference between temperature treatment since at mid ripening stage. Although chlorophyll a/b ratio under high temperature was decreased from heading to 15 days after heading, that was gradually increased since 15 days after heading. Protein concentrations of rice leaves for ripening stage was a similar pattern with chlorophyll changes. The rate of photosynthesis at 14 days after heading under high temperature was higher than those of control temperature, but there was no difference at those of 7 and 34 days after heading between two temperature treatment. Free sugars under high temperature treated leaves were lower than control temperature. Consequently, these results exhibit that high temperature accelerate leaf physiological activity as chlorophyll synthesis and photosynthesis rate unlike the deterioration of grain filling.

The response of the freshwater microalga Chlorella vulgaris to mercuric ion (Hg2+) stress was examined using chlorophyll a fluorescence image analysis and O-J-I-P analysis as a way to monitor the toxic effects of mercury on water ecosystems. The levels of photosynthetic pigments, such as chlorophyll a and b and carotenoids, decreased with increasing Hg2+ concentration. The maximum photochemical efficiency of photosystem Ⅱ(Fv/Fm) changed remarkably with increasing Hg2+ concentration and treatment time. In particular, above 200 μM Hg2+, considerable mercury toxicity was seen within 2 h. The chlorophyll a fluorescence transient O-J-I-P was also remarkably affected by Hg2+; the fluorescence emission decreased considerably in steps J, I, and P with an increase in Hg2+ concentration when treated for 4 h. Subsequently, the JIP-test parameters (Fm, Fv/Fo, RC/CS, TRo/CS, ETo/CS, ΦPO, ΨO and ΦEO) decreased with increasing Hg2+ concentration, while N, Sm, ABS/RC, DIo/RC and DIo/CS increased. Therefore, a useful biomarker for investigating mercury stress in water ecosystems, and the parameters Fm, ΦPO, ΨO, and RC/CS can be used to monitor the environmental stress in water ecosystems quantitatively.

Loss of leaf green color results from chlorophyll (Chl) degradation in the chloroplasts, but little is known about how Chl catabolism is tightly regulated throughout development. Using the stay-green (sgr) mutant in rice which maintains leaf greenness during senescence, we identified SGR by map-based cloning. SGR is a function-unknown gene encoding senescence-induced chloroplast protein. Transgenic rice overexpressing SGR produced yellow leaves, indicating that SGR regulates Chl degradation at the transcriptional level. Leaf stay-greenness of the sgr mutant is mainly associated with a failure in the destabilization of light-harvesting complexes (LHCs) of thylakoid membranes, which is a prerequisite event for the degradation of Chl and LHCs during leaf senescence. SGR binds to light harvesting complex of photosystem II (LHCII), but its biochemical role is so far unknown. During senescence, Chl should be degraded rapidly and safely because Chl catabolic intermediates producing ROS under light are extremely toxic to the plant cells. For safe and rapid degradation of Chl and its catabolic intermediates, Chl catabolic enzymes (CCEs) must catch the Chl intermediates effectively. In recent years, although molecular functions of SGR and CCEs have been characterized in detail, their biochemical mechanism for Chl detoxification remain elusive. Here we show that all five CCEs also specifically interact with LHCII. In addition, SGR and CCEs interact directly or indirectly with each other at LHCII, and SGR is essential for recruiting CCEs in senescing chloroplasts. These data indicate a predominant role for the SGR-CCE-LHCII protein interaction in the breakdown of LHCII-located Chl, likely to allow metabolic channeling of phototoxic Chl breakdown intermediates upstream of nontoxic pFCC.

Development of transgenic plant with desirable traits to cultivated plant is one of the important procedures in plant molecular breeding. However, applicable assessment of transgenic plant in laboratorial scale is not much except cultivating transgenic plant for a whole life in field condition. Here, we analyzed chlorophyll fluorescence in three transgenic soybean lines with AtMYB44 transcription factor for assessment of photosynthetic activity under abiotic stresses such as drought. Soybean varieties used in this study were ‘Bert’ and ‘Bert’ derived three transgenic soybeans, ‘AtMYB44 CM35101’, ‘AtMYB44 CM2471’, and ‘AtMYB44 CM4481’. Analyzed five different chlorophyll fluorescence variables are maximum PSII quantum yield (QY_max), steady state PSII quantum yield (QY_Lss), steady state non-photochemical quenching (NPQ_Lss), coefficient of photochemical quenching in steady-state (Qp_Lss), and fluorescence declineratio in steady-state (Rfd_Lss). To determine main chlorophyll fluorescence variable affected by abiotic stress, principal component analysis (PCA) was conducted with five chlorophyll fluorescence variables measured from four varieties. QY_Lss and NPQ_Lss were main chlorophyll fluorescence variables to evaluate abiotic stress, particularly in drought stress. In comparison with transgenic soybean lines based on chlorophyll fluorescence variables, ‘AtMYB44 CM2471’ and ‘AtMYB44 CM4481’ are more tolerant to drought than the others. Interestingly, three transgenic soybean lines which have a same AtMYB44 gene with different regions of chromosome revealed the quite different responses of chlorophyll fluorescence to drought treatment.

An average Korean known to ingest 3.4 times of the nitrate ADI level are found to have taken in 97% of nitrates through vegetables. This study analyzed the contents of nitrates and chlorophyll in organic Chinese cabbages, a major favorite vegetable for Koreans, with a view to lowering daily intake of nitrate. Our findings show that, in organically cultivated cabbages, the further outward the leaf was located, the more significantly the contents of nitrates increased, with the midrib and leaf blade showing positive relationship of r=0. 789 , and =0.659 , respectively. In the case of the midrib, the contents increased as high as 79 times ranging from 40ppm for the innermost leaf to 3, 177ppm for the outermost one, and when it comes to the leaf blade, the contents rose as high as 87 times, showing a range of 40 - 3,481ppm. Our findings also suggest that it is advisable to discard 1/3 of the outermost leaves before eating Chinese cabbages, since the outer leaves with known high contents of chlorophyll also have high contents of nitrates.

As cool-season plant, Panax ginseng C. A. Meyer is planted under shade-installation with tall front and low rear. However, at different planting positions, distinct differences come out because ginseng grows at the same position within 3~5 years and the growth circumstance changes a lot by the shade-installation. So, in this study, changes of temperature, photosynthesis and chlorophyll fluorescence with varieties of shading material and planting position were investigated. Light transmittances by polyethylene shade net and silver-coated shading plate as planting materials were measured according to different planting positions. Photosynthetic rate and chlorophyll fluorescence were measured by LI-6400-40 (Li-Cor). According to different planting positions, light intensity was higher in silver-coated shading plate than in polyethylene shade net, and higher at front than rear. Also, photosynthetic rate showed the same tendency, which had a positive correlation to light intensity. But this treatment caused a lower Fo compared with polyethylene shade net because of the stress by light and temperature. Also, Fv/Fm and ETR were higher in silver-coated shading plate. Fo was similar at front and rear according to silver-coated shading plate and ETR was higher at front.