• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.1
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• pp.1-8
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• 2018

The purpose of this study was to investigate the effects of light intensity on the initial growth response of three woody plants for indoor landscaping; Ardisia pusilla, Clusia rosea and Fatsia japonica. The plants were planted in 10cm pots, the light intensities used were of four levels-15, 30, 60, $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD-and light irradiation time was set to 12/12 (day/night). Growth responses including plant height, leaf length, leaf width, chlorophyll fluorescence (Fv/Fm), SPAD and Hunter values were measured at 4-week intervals, and shoot weight and root weight of fresh and dry plants were measured after completion of the experiment. Fatsia japonica tended to show greater leaf length and leaf width as light intensity became greater, while other plants did not show any significant differences at different light intensities. The Fv/Fm value of the Ardisia pusilla was found to be stressed at 60 and $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, while the Fv/Fm values were within normal range with other plants or at other light intensity levels to show no stress. Only Clusia rosea showed significantly different SPAD values at $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and there was no significant SPAD value difference found with other plants or at other light intensity levels. While Hunter values of the Ardisia pusilla did not show any significant differences at any light intensity levels, Clusia rosea and Fatsia japonica showed specificity in L, a and b values at 60 and $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. Ardisia pusilla showed a big stem growth at $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and Clusia rosea showed a steady growth at 60 and $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$.

• Journal of Photoscience
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• v.9 no.2
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• pp.158-161
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• 2002

UV-B radiation gives harmful effects on plants, such as production of several types of DNA lesions, and growth inhibition. On the other hand, plants have some protective mechanisms, including filtering effect due to accumulation of phenolic compounds in epidermal cells and reactivation of DNA lesions, which are enhanced by UV-B irradiation. We have investigated the mechanism of UV-B effects on plants using cucumber seedlings as plant materials. Cucumber plants were cultivated in an artificially lit growth chamber. Supplemental UV-B irradiation, of which intensity was almost equal to the level of natural sunlight, retarded the growth of first leaves. The growth retardation must result trom the inhibition of cell division and/or cell growth. Microscopical observation of leaf epidermis suggested that the growth retardation might be mainly caused by cell growth inhibition. The retardation was, however, restored within 2 or 3 days after the termination of UV-B irradiation. It is known that UV-B irradiation lowers the activity of photo system II (PS II). In the present experimental conditions, however, UV-B irradiation has little effect on PS II activity as estimated by chlorophyll fluorescence. The stomatal conductance, a major factor determining photosynthetic rate, of first leaves increased during the growth. The increase of stomatal conductance was suppressed by UV-B irradiation and restored by termination of the irradiation. It has not been clear, however, what mechanisms are involved in the suppression of increase of stomatal conductance.

• Journal of Applied Biological Chemistry
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• v.48 no.1
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• pp.1-6
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• 2005

Analysis of chlorophyll (Chl) fluorescence implicated treatment of 40 mM NaCl decreased maximal photochemical efficiency of photosystem II (PSII) (Fv/Fm), actual quantum yield of PSII (${\Phi}_{PSII}$), and photochemical quenching (qP) in rice, but increased non-photochemical quenching (NPQ). Decreases in Fv/Fm, ${\Phi}_{PSII}$, and qP were significantly alleviated by $30\;{\mu}M$ jasmonic acid (JA), while NPQ increase was enhanced. Transcription levels of antioxidant isoenzyme genes were differentially modulated by NaCl treatment. Expression of cCuZn-SOD2 gene increased, while those of cAPXb, CATb, and CATc genes decreased. JA prevented salt-induced decrease of pCuZn-SOD gene expression, but caused greater decrease in mRNA levels of cAPXa and Chl_tAPX genes. Investigation of vacuolar $Na^+/H^+$ exchanger (NHX2) and 1-pyrroline-5-carboxylate synthetase (P5CS) gene expressions revealed transcription level of NHX2 gene was increased by JA, regardless of NaCl presence, while that of P5CS gene slightly increased only in co-presence of JA and NaCl. Unlike JA, ${\gamma}$-radiation rarely affected expressions of antioxidant isoenzyme, NHX2, and P5CS genes, except for increase in mRNA level of Chl_tAPX and decrease in that of pCuZn-SOD. These results demonstrate enhanced salt-tolerance in JA-treated rice seedlings may be partly due to high transcription levels of pCuZn-SOD, NHX2, and P5CS genes under salt stress.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.3
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• pp.127-137
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• 2007

To confirm whether or not the Electrochemical Disinfection System (EDS) meet with the D-2 regulation established by IMO (International Maritime Organization), the biological treatment efficacy of the EDS was assessed using three groups of natural marine plankton (bacteria, $10-50\;{\mu}m$ and $>50\;{\mu}m$ sized organisms). Influent water was passed through the EDS under the flow velocity ($23.8\;m^3/hr$) and test design was consisted of control (no treatment) and experimental (10 ppm and 30 ppm) condition for total residual chlorine (TRC). And the biological condition of the influent water followed the standards established by the guidelines for the approval of ballast water management systems. The disinfection efficacy of the $10-50\;{\mu}m$ sized organisms (phytoplankton) was assessed by three kinds of measurements using photomicroscope, epifluorescence microscope and fluorometer (fumer Designs 10-AU). After being passed through the EDS, all motile phytoplankton lost their motility under photomicroscope, the colour of chlorophyll fluorescence fumed from red into green under epifluorescence, and the high chlorophyll fluorescence (Expt. 1: 6.95, Expt. 2: 7.11) detected by fluorometer decreased into value not detected. These results indicated phytoplankton community was totally killed after electrochemical disinfection treatment. Survivorship of the larger organisms than $50\;{\mu}m$ was determined based on the appendage's movement under a stereomicroscope. Natural assemblage collected from ambient seawater was killed shortly after being passed through the EDS, whereas some Artemia remained alive. However, no live Artemia was found after 24 hour further exposure to each TRC concentration (10 and 30 ppm) under darkness. After electrochemical treatment, the target bacteria such as aerobes, coliform and Escherichia coli were completely killed on the basis of CFU (colony forming unit) on Petrifilm plate ($3\;M^{TM}$) after 48 hr incubation. Moreover, no regrowth was found in the three groups of plankton during five days under additional exposure to the treated water. These results indicated that the disinfection efficiency of the EDS on the three groups of plankton satisfy D-2 regulation.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.196-205
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• 2021

This research was conducted in order to analyze the difference in yield through the changes in growth and measuring the photosynthesis efficiency in cherry tomatoes. Seedlings of cherry tomato 'Nonari' were used as scion and non-grafted control, while 4 different grafted tomatoes 'Powerguard', 'T1', 'L1', and 'B.blocking' were used as rootstocks. Plants grafted onto 'B.blocking' produced the highest fruit yield (417.5 g plant^-1), whereas non-grafted plant 'Nonari' had the lowest fruit yield, (354.2 g plant^-1) at the latter period of cherry tomatoes in May. The flowering position in May, plant grafted onto 'B.blocking', showed 14-17 cm, whereas non-grafted plant 'Nonari' showed 10-14 cm. The growth strength on May 15, non-grafted plant 'Nonari', showed 8.43 mm which was the lowest value among the treatments. Grafted plants kept the growth balance until the end of the harvest that led to an increase in fruit yield, while non-grafted plant weakened the vigor earlier that led to a decrease in fruit yield. Grafted plants showed higher values of chlorophyll fluorescence variables than the values of non-grafted plant. These results indicate that grafting influenced fruit yield which was observed as maintaining growth balance for longer and an increase in photosynthesis efficiency compared to non-grafting.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.878-885
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• 2016

A study was conducted to examine the effects of light quality on the growth and phytochemical contents of ice plant in a closed-type plant production system. Seeds were sown in a 128-cell plug tray using rockwool. The seedlings were then transplanted into a deep floating technique system with recirculating nutrient solution (EC $1.5dS{\cdot}m^{-1}$, pH 6.5) in a closed-type plant production system. The nutrient solution was supplied at two weeks after transplanting with 2.0 mM NaCl concentration in all treatments for the development of the bladder cells. The three light sources with different light qualities used were as followed; FL (fluorescent lamps), combined RW LED (red:white = 7:3), and combined RBW LED (red:blue:white = 8:1:1) at $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD with a photoperiod of 14/10 hours (light/dark). The results showed that the FL treatment had the greatest growth enhancement effects on the leaf area and the fresh and dry weights of the shoots and roots. The SPAD values were significantly higher under the FL and RBW LED treatments, at 29.8 and 30.6, respectively. No significant difference was observed in salinity under all treatments. Chlorophyll fluorescence was significantly higher under the FL treatment. The total phenol content and antioxidant activity were the highest under the RBW LED treatment. The total flavonoid content was significantly higher under the RBW LED and FL treatments. Hence, the results indicate that the growth of ice plant was maximized under the FL treatment. The phytochemical contents were maximized under the RBW LED treatment.

• Journal of Applied Biological Chemistry
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• v.58 no.3
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• pp.273-279
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• 2015

Phaeodactylum tricornutum is a model diatom that its genomic information and biological tools are well established. In this study, a gene encoding (E)-4-hydroxy-3-methylbut-2-enyl diphosphate reductase (PtHDR), a terminal enzyme of the methylerythritol phosphate pathway regulating chlorophyll and carotenoid biosynthesis, was isolated from P. tricornutum. The isolated gene was cloned into pPha-T1 vector containing fcpA promoter to prepare pPha-T1-HDR plasmid. As a positive control, pPha-T1-eGFP plasmid was constructed with egfp gene. Stable nuclear transformation was carried out with these plasmids by particle bombardment method and zeocin resistant colonies of P. tricornutum were selected on f/2 agar plate. In result, transformation efficiency was evaluated according to the amount of plasmid DNA coated with gold particles. Integration of introduced plasmids was confirmed with genomic DNA of each transformant by polymerase chain reaction. The eGFP fluorescence was visible in the cytoplasm, indicating that eGFP was successively expressed in P. tricornutum system. The transcript level of exogenous Pthdr gene was evaluated with the obtained transformants. The results presented here demonstrated that introduction of Pthdr gene into P. tricornutum chromosome succeeded and expression of PtHDR was enhanced under the fcpA promoter.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.673-679
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• 2012

This study was conducted to examine the effect of artificial light source and photoperiod on the growth of leaf lettuce (Lactuca sativa L.) 'Seonhong Jeokchukmyeon' in a closed-type plant production system. Seedlings were grown under 3 light sources, fluorescent lamp (FL, Philips Co. Ltd., the Netherlands), WL #1 (Hepas Co. Ltd., Korea), and WL #2 (FC Poibe Co., Ltd., Korea), each with 3 photoperiods, 12/12, 18/6, and 24/0 (Light/Dark). An irradiance spectrum analysis showed that FL has various peaks in the 400-700 nm range, while WL #1 and WL #2 have only one monochromatic peak at 450 and 550 nm, respectively. The greatest plant height, fresh and dry weights were obtained in the 24/0 (Light/Dark) photoperiod. The 24/0 (Light/Dark) photoperiod treatment promoted vegetative growth of the leaf area. Length of the longest root, number of leaves, fresh weight, and total anthocyanin contents were greater in FL than in either WL #1 or #2. The greatest chlorophyll fluorescence (Fv/Fm) was found in the 12/12 (Light/Dark) photoperiod with FL treatment. The energy use efficiency of the LED increased by about 35-46% as compared to FL. Results suggest a possibility of LED being used as a substitute light source for fluorescent lamp for lettuce cultivation in a plant factory system.

• Korean Journal of Environmental Biology
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• v.22 no.4
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• pp.537-542
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• 2004

To reveal the relationship between the changes in the growth and photo- synthesis induced by low dose radiation, red pepper (Capsicum annuum L.) plants were serially irradiated three times with gamma rays of 0.5, 1, 2, 3, and 4 Gy. The plant growth was monitored by the fresh weight, the stem length, and the leaf length & width. All the irradiation groups (0.5-4 Gy) were stimulated in growth at 1 day after the $1^{st}$ irradiation (DA1I), but rather inhibited at 3 days after the $3^{rd}$ irradiation (DA3I). The maximum photochemical efficiency (Fv/Fm), the photochemical quenching (qP), the non-:photochemical quenching (NPQ) and the apparent rate of the photosynthetic electron transport (ETR) were used to represent the changes in the photosynthesis by the serial irradiation. The irradiation groups except 0.5 Gy had higher Fv/Fm values at 3 DA3I than the control one. After the 3$^{rd}$ irradiation, the qP values appeared to be a little lower in the 1-4 Gy groups than in the control and 0.5 Gy ones. In contrast, the NPQ values were rather higher in the irradiation groups except 0.5 Gy. During the whole experimental period, the ETRs decreased in the control group but remained relatively constant in the 4-Gy one. In conclusion, the results obtained indicate that the stimulatory effect of ionizing radiation on the plant growth was determined by the incident dose of the single irradiation rather than by the cumulative one of the serial irradiation. They also demonstrate that the growth stimulation induced by a low dose radiation could not be positively correlated with an alteration in the photosynthesis. Additionally, we discuss in text that an ionizing radiation may partly protect the leaf senescence by delaying the development of the plants.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.185-193
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• 2008

We evaluated the response to salt stress of two different ginseng lines, STG3134 and STG3159, which are sensitive and tolerant, respectively, to salt treatment. Plants were exposed to a 5 dS/m salt solution, and chlorophyll fluorescence was measured. STG3134 ginseng was more sensitive than STG3159 to salt stress. To characterize the cellular response to salt stress in the two different lines, changes in protein expression were investigated using a proteomic approach. Total protein was extracted from detached salt-treated leaves of STG3134 and STG3159 ginseng, and then separated by two-dimensional polyacrylamide gel electrophoresis(2-DE). Approximately 468 protein spots were detected by 2-DE and Coommassie brilliant blue staining. Twenty-two proteins were found to be reproducibly up- or down-regulated in response to salt stress. Among these proteins, twelve were identified using MALDI-TOF MS and ESI-Q-TOF and classified into several functional groups: photosynthesis-related proteins(oxygen-evolving enhancer proteins 1 and 2, rubisco and rubisco activase), detoxification proteins(polyphenol oxidase) and defense proteins($\beta$-1,3-glucanase, ribonuclease-like storage protein, and isoflavone reductase-like protein). The protein levels of ribonuclease-like storage protein, which was highly induced in STG3159 ginseng as compared to STG3134, correlated tightly with mRNA transcript levels, as assessed by reverse-transcription(RT)-PCR. Our results indicate that salinity induces changes in the expression levels of specific proteins in the leaves of ginseng plants. These changes may, in turn, playa role in plant adaptation to saline conditions.