• 생명과학회지
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• 제11권2호
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• pp.166-172
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• 2001

Various types of the seeding of bottle gourd widely used as a rootstock of watermelon has been required to satisfy the farmers need. The study was done to determine the effect of light quality of blue, red and far-red lights treated with light emitting diodes on growth and morphology of bottle goured seeding and chlorophyll content of its cotyledons. The lights were treated in the growth chamber for 7 days to the seeding elapsed 8 days after sowing under natural condition, and 64 hole trays with commercial bedsoil. Plant height, length and diameter of hypocotyl, leaf area of cotyledon and first true leaf, its leaf length, number of true leaves, fraction and total dry weight were measured. Red light shortened and slenderized the hypocotyl, which lengthened by far-red light and thickened by blue light. Plant height was declined in order of far-red light treatment, blue and red lights mainly due to difference of hypocotyl length, Area and length of the first true leaf became smaller and shorter under far-red light than under the other lights. However, blue light increased leaf area of cotyledons. Two cultivars cv. Yongjadaemok and cv. Kunghap had different response to the light treatments in total seedling dry weight(dw); far-red and red light treatments showed the greatest and the least dw of hypocotyl, respectively, while blue and red lights did the greatest dw of the other organs. Among the ratio of each organ dw to total dw, those of hypocotyl and true leaves were different between the light treatments; the highest ratio of hypocotyl dw to total dw was observed in far-red light treatment but the lowest was in red light treatment. Those of the true leaves were the lowest in far-red light and similar response in blue or red light treatment. Chlorophyll content of cotyledons was decreased in order of red light treatment, blue and far-red lights, meaning that short period light treatment may influence photosynthesis of seeding and afterward its growth.

• Journal of Biosystems Engineering
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• 제28권2호
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• pp.151-156
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• 2003

This study was performed to investigate the effect of light quality on evapotranspiration and graft-taking characteristics of watermelon grafted seedlings using blue, red and far-red light-emitting diodes (LED). At initial stage of graft-taking, blue light increased the evapotranspiration rate (EVTR) of grafted seedlings as compared to effects of red and far-red on EVTR of grafted seedlings. Grafted seedlings graft-taken under red and blue LED showed the high graft-taking of 100% and 96%, respectively. However, grafted seedlings graft-taken under far-red LED showed the graft-taking of 80% and survival of 60% with low seedlings quality after hardening. The stem of grafted seedlings graft-taken under red light was elongated but blue light suppressed the stem elongation. The leaf area of grafted seedlings graft-taken under red light was increased. It is concluded that the effect of light quality using LED on graft-taking of watermelon grafted seedlings was significantly recognized. Considering the duration of quality of grafted seedlings graft-taken under artificial lighting, LED could be used as an effective lighting sources to validate the continuance of seedling quality.

• 한국환경농학회지
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• 제30권4호
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• pp.414-418
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• 2011

우리나라에서 주로 사용되고 있는 흑색 비닐멀칭과 신개발된 적색 비닐멀칭의 표면 반사광 특성을 분석하고 참외와 토마토에 대한 영향을 구명하여 작물생산에 대한 적용 가능성을 검토하였다. 적색 비닐멀칭의 표면에서 반사된 적색광과 초적색광의 일일 누적 강도는 흑색 비닐멀칭보다 2.6배 강했다. 적색광과 초적색광 반사광의 강도는 적색 비닐멀칭의 표면 높이 30 cm에서 가장 강하였다. 일중 태양광 강도가 강한 오후 1시 20분의 흑색 비닐멀칭의 Red/F-Red는 1.14, 적색 비닐멀칭은 0.93, 태양광은 1.16으로 적색 비닐멀칭이 흑색 비닐멀칭보다 초적색광 강도가 높았다. 적색 비닐멀칭의 Red/F-Red는 표면 높이 30 cm에서 가장 낮았으며 표면높이가 높아질수록 초적색광 강도가 감소하여 Red/F-Red는 증가하였다. 적색 비닐멀칭 반사광의 Red/F-Red는 정오부터 오후 4시경까지는 흑색 비닐멀칭보다 낮게 경과하였다. 흑색 비닐멀칭 처리구보다 적색 비닐멀칭 처리구의 참외 과실의 무게가 증가하여 수량이 증가하였고 당도가 높았다. 토마토의 과실 무게와 당도도 적색 비닐멀칭 처리가 흑색 비닐멀칭 처리구보다 높았다. 지중온도는 적색 비닐멀칭 처리가 흑색 비닐멀칭 처리보다 다소 낮은 경향이었다. 따라서 적색 비닐멀칭으로 토양을 피복하면 작물생산에 적색광과 초적색광을 더 많이 이용할 수 있을 것으로 판단된다.

• 한국작물학회지
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• 제48권6호
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• pp.460-464
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• 2003

본 연구는 벼 종자의 파종 후 발아, 유묘출현 및 생육 초기에 가하여지는 광질처리가 유묘 출현, 생장, 형태, 엽록소 함량 및 광합성율에 미치는 영향을 조사하여 벼의 육묘에 이용되고 있는 부직포의 색상을 전환할 필요가 있는가를 검토하고자 실시하였으며 그 결과를 요약하면 다음과 같다. 1. 파종 직후에 가하여지는 광질처리에서 유묘출현율은 조사일 모두 일미벼에서는 광질처리간 차이가 없었다. 그러나 동진벼와 대산벼에서는 원적색광 처리에서 가장 낮았으며, 청색광과 적색광간에는 차이가 거의 없었다. 2. 파종 직후에 가하여지는 광질처리로 인하여 원적색광 처리에서 초장과 엽장이 가장 짧았던 반면, 적색광은 뿌리수를 증대시켰다. 3. 파종 직후에 가하여지는 광질처리로부터 지상부 건물중은 청색광 처리에서, 뿌리의 건물중은 적색광 처리에서 가장 많았던 반면, 지상부 및 뿌리 건물중 모두 원적색광에서 가장 적었다. 4. 엽록소 함량과 광합성율 모두 품종간에는 일정한 경향이 없었으나, 광질처리에서는 이들 모두 적색광에서 가장 높고, 청색광, 원적색광 순으로 감소하였다.

• BMB Reports
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• 제29권6호
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• pp.535-539
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• 1996

The activation of phospholipase D (PLD) catalyzes hydrolysis of phosphatidylcholine (PC) to phosphatidic acid (PA) and choline in plants as well as animals. To determine the presence of PLD in oat cells, we prepared inside-out plasma membrane and cytosolic fractions from oat tissues. PLD activities in both cytosol and plasma membrane were detected by ion chromatography method. The activity of PLD in plasma membrane was dependent upon $Ca^{2+}$ concentration and was heat stable. To investigate whether G-protein couples to PLD, the effects of $GTP{\gamma}S$ and $GDP{\beta}S$ on the PLD activity were measured. PLD activity was dramatically increased 300~400% in the presence of 50 ${\mu}M$ $GTP{\gamma}S$ but not in the presence of 50 ${\mu}M$ $GDP{\beta}S$. These results indicate that G-protein may be involved in regulation of PLD activity. To identify whether PLD is regulated by red light receptor, phytochrome, we irradiated red, far-red, or red/far-red/red light on oat protoplasts. PLD activity has increased 5-fold and 3-fold by treatment with red light and red/far-red/red light, respectively. In contrast, irradiation with far-red light had little or no effect on PLD activity. These results suggest that phytochrome regulates PLD activity through activation of G-protein in oat cells.

• 생명과학회지
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• 제22권5호
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• pp.681-686
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• 2012

빛이 굴중성과 뿌리 생장에 미치는 영향을 알아보기 위해 Arabidopsis phytochrome mutant를 이용하여 뿌리 생장과 굴중성 반응을 측정하였다. $PhyA$의 뿌리 생장은 white light를 제외한 모든 빛 조건에서 WT와 비교하여 촉진되었다. 특히 red light에서 키웠을 때 다른 mutant와는 달리 뿌리 생장이 촉진되었다. 반면에 phyB는 모든 빛 조건에서 키웠을 때 뿌리 생장이 억제되었으며, 특히 double mutant인 $phyAB$는 white light와 red light에서 키웠을 때 뿌리 생장이 가장 많이 억제되었다. $PhyA$의 굴중성 반응은 far-red light에서 키웠을 때를 제외하고 모든 빛 조건에서 키웠을 때 WT와 비교하여 촉진되었다. 한편 $phyAB$는 모든 조건에서 모두 굴중성 반응이 억제되었다. Ethylene 생합성을 조절하는 효소인 ACS transcript 수준은 white light와 red light에서 키웠을 때 $phyA$가 높게 나타났으며, far-red light에서 키웠을 때는 $phyA$의 transcript 수준이 억제되었다. 결론적으로 뿌리 생장과 굴중성 반응은 $phyB$의 $P_{fr}$에 의해 조절된다.

• 한국환경농학회지
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• 제32권2호
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• pp.123-127
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• 2013

적색광을 이용한 국화의 일장연장 처리기술을 개발하기 위하여 국화의 개화억제를 위한 적색광 강도를 구명하고 생육에 대한 영향을 검토하였다. 국화는 적색광에 의한 파야처리로 개화가 억제되었고 연속된 초적색광 처리로 개화하여 개화의 광가역적 반응을 나타냈다. 인공광 생육실 환경하에서 적색광 $1.4{\mu}mol/m^2/s$ (PAR) 로 일장연장 처리시 국화의 개화가 완전히 억제되었다. 적색광 $1.4{\mu}mol/m^2/s$ 처리는 관행의 전구식형광등 50 Lux 처리와 같이 국화의 개화를 억제시켰다. 적색 LED를 이용한 일장연장 처리로 관행의 전구식형광등 처리보다 국화의 초장은 17 %, 엽면적은 48 % 유의하게 증가하였고 엽수와 생체중은 각각 11 %, 36 % 증가하는 경향이었다.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1998년도 The 12th Symposium on Plant Biotechnology Vol.12
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• pp.83-96
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• 1998

The plant pigment proteins phytochromes are a molecular light sensor or switch for photomorphogenesis involving a variety of growth and developmental responses of plants to red and far-red wavelength light. Underscoring the photomorphogenesis mediated by phytochromes is the light signal transduction at molecular and cellular levels. For example, a number of genes activated by the phytochrome-mediated signal transduction cascade have been identified and characterized, especially in Arabidopsis thaliana. The light sensor/switch function of phytochromes are based on photochromism of the covalently linked tetrapyrrole chromophore between the two photoreversible forms, Pr and Pfr. The photochromism of phytochromes involves photoisomerization of the tetrapyrrole chromophore. The "photosensor" Pr-form ("switch off" conformation) of phytochromes strongly absorbs 660 nm red light, whereas the "switch on" Pfr-conformation preferentially absorbs 730 nm far-red light. The latter is generally considered to be responsible for eliciting transduction cascades of the red light signal for various responses of plants to red light including positive or negative expression of light-responsive genes in plant nuclei and chloroplasts. In this paper, we discuss the structure-function of phytochromes in plant growth and development, with a few examples of biotechnological implications.

• Journal of Photoscience
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• 제7권3호
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• pp.79-86
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• 2000

Phytochromes are red and far-red light absorbing photoreceptors for photomorphogenesis in plants. The red/far wavelength reversible biliproteins are made up of two structural domains. The light-perceiving function of the photoreceptor resides in the N-terminal domain, whereas the signal transducing regulatory function is located within the C-terminal domain. The characteristic role of the phytochromes as phtosensory molecular switches is derived from the phototransformation between two distinct spectral forms, the red light absorbing Pr and the far-red light absorbing Pfr forms. The photoinduced Pr Pfr phototransformation accompanies subtle conformational changes throughout the phytochrome molecule. The conformational signals are subsequently transmitted to the C-terminal domain through various inter-domain crosstalks and induce the interaction of the activated C-terminal domain with phytochrome interacting factors. Thus the inter-domain crosstalks play critical roles in the photoactivation of the phytochromes. Posttranslational modifications, such as the phosphorylation of Ser-598, are also involved in this process through conformational changes and by modulating inter-domain signaling.

• 한국산림과학회지
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• 제99권5호
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• pp.750-754
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• 2010

Among the environmental conditions employed in micropropagation, light quality plays an important role in growth, specially morphogenesis and photosynthesis. The effect of radiation quality (350-740 nm) on the development and growth of zygotic embryos and in vitro plantlets of open-pollinated chestnut (Castanea crenata S. et Z.) were studied. Two types of explants were exposed for 4 weeks to cool white (W, as control), monochromatic red (R, peak emission 650 nm), monochromatic blue (B, peak emission 440 nm), red+blue (R+B, 1:1), or red+far-red (R+Fr, 1:1, far-red peak emission 720 nm) radiation from a light-emitting-diode (LED) system. While the zygotic embryos showed positive photoblastic behavior, their germination was inhibited by blue radiation. Hypocotyl elongation and root development were promoted by red radiation. The emergence of primary leaf and its expansion were faster under blue than under red radiation. In the plantlets, red and red+far-red radiation significantly increased the formation and growth of the root, whereas blue light reduced rooting. Therefore, radiation quality appears to influence some steps in the development of zygotic embryos and plantlets in the chestnut.