• 약학회지
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• 제35권6호
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• pp.461-465
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• 1991

Silica-based gel filtration chromatography has been used to characterize molecular weight of proteins. However, the molecular weight measured by this method was distorted by protein-silica interactions like hydrophobic and electrostatic forces. Therefore, we characterized protein-silica interaction using two forms of phytochrome (124 kDa) having different hydrophobicity and surface charge. PH and ionic strength affected the retention time of phytochrome suggesting that electrostatic force is the major interaction between protein and silica surface.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2005년도 제12회 학술대회 논문초록
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• pp.21-23
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• 2005

• 한국잡초학회지
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• 제10권4호
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• pp.305-311
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• 1990

잡초종자(雜草種子) 발아(發芽)에 미치는 광(光)의 영향(影響)을 구명(究明)하기 위하여 왕바랭이, 냉이, 털비름, 개비름, 쇠비름, 명아주, 까마중, 강아지풀, 바랭이를 공시(供試)하여 시험(試驗)을 수행(遂行)하였다. 1. 대부분의 공시잡종(供試草種)은 $25^{\circ}C$ 이상(以上)에서 강(强)한 광발아성(光發芽性)을 보였으며 낮은 온도하(溫度下)에서는 발아(發芽)가 저조(低調)하였다. 그러나 피, 강아지풀, 바랭이는 대체적으로 발아율(發芽率)이 떨어진 반면, 털비름, 개비름, 쇠비름은 높은 발아율(發芽率)을 유지(維持)하였다. 2 개비름, 쇠비름, 털비름은 적색광하(赤色光下)에서 발아(發芽)가 촉지(促進)되었으며 원적색광(遠赤色光)에서는 발아(發芽)가 현저히 억제(抑制)되었다.3. 털비름, 개비름, 쇠비름은 red/far-red 광(光)에 의한 가역반응(可逆反應)을 나타내는 것으로 보아 종자발아시(種子發芽時) Phytochrome이 관여하고 있음을 알 수 있었고 피, 왕바랭이는 적색광(赤色光) 및 자색광(白色光)과 청색광(靑色光) 연속조사하(連續照射下)에 관여하는청색광(靑色光) 색소(色素) (HIR 색소(色素))가 관여하는 것으로 추정(推定)되었다.

• Molecules and Cells
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• 제43권7호
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• pp.645-661
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• 2020

Leaf senescence is a developmental process by which a plant actively remobilizes nutrients from aged and photosynthetically inefficient leaves to young growing ones by disassembling organelles and degrading macromolecules. Senescence is accelerated by age and environmental stresses such as prolonged darkness. Phytochrome B (phyB) inhibits leaf senescence by inhibiting phytochrome-interacting factor 4 (PIF4) and PIF5 in prolonged darkness. However, it remains unknown whether phyB mediates the temperature signal that regulates leaf senescence. We found the light-activated form of phyB (Pfr) remains active at least four days after a transfer to darkness at 20℃ but is inactivated more rapidly at 28℃. This faster inactivation of Pfr further increases PIF4 protein levels at the higher ambient temperature. In addition, PIF4 mRNA levels rise faster after the transfer to darkness at high ambient temperature via a mechanism that depends on ELF3 but not phyB. Increased PIF4 protein then binds to the ORE1 promoter and activates its expression together with ABA and ethylene signaling, accelerating leaf senescence at high ambient temperature. Our results support a role for the phy-PIF signaling module in integrating not only light signaling but also temperature signaling in the regulation of leaf senescence.

• BMB Reports
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• 제41권9호
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• pp.645-650
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• 2008

Nucleoside diphosphate kinase (NDPK) is involved in multiple signaling pathways in mammalian systems, including G-protein signaling. Arabidopsis NDPK2, like its mammalian counterparts, is multifunctional despite its initial discovery phytochrome-interacting protein. This similarity raises the possibility that NDPK2 may play a role in G-protein signaling in plants. In the present study, we explore the potential relationship between NDPK2 and the small G proteins, Pra2 and Pra3, as well as the heterotrimeric G protein, GPA1. We report a physical interaction between NDPK2 and these small G proteins, and demonstrate that NDPK2 can stimulate their GTPase activities. Our results suggest that NDPK2 acts as a GTPase-activating protein for small G proteins in plants. We propose that NDPK2 might be a missing link between the phytochrome-mediated light signaling and G protein-mediated signaling.

• 생명과학회지
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• 제18권2호
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• pp.148-153
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• 2008

Arabidopsis의 피토크롬 2중 돌연변이형 (phrAB)은 야생형 (WT)과 비교하여 뿌리의 굴중성 반응이 지연되었다. 중력 자극을 받은 지 8시간 후에 돌연변이체의 굴중성 반응은 야생형의 48%를 나타내었다 지연된 반응은 중력 자극을 준 후 1.5 시간 뒤에 나타났다. 12시간 동안 야생형과 돌연변이형의 뿌리 절편에서 에틸렌 생성을 측정하였다. 돌연변이형의 에틸렌 생성은 12시간이 경과한 후에 야생형의 40% 정도로 감소되었다. 이러한 결과는 피토크롬이 에틸렌 생성과 연관되어 있음을 제시하고 있다. 일반적으로 에틸렌은 식물의 뿌리나 줄기를 억제한다. 본 연구에서는 에틸렌 전구체인 1-aminocycloprpane-1-carboxylic acid (ACC)를 처리하여 뿌리의 생장을 측정하였다. 야생형은 ACC 존재하에 뿌리 생장이 억제되었으나, 돌연변이형은 야생형만큼 억제를 나타내지 않았다. 이 결과를 확인하기 위하여 ACC 존재하에 굴중성 반응을 측정한 결과, 야생형은 ACC가 없는 경우와 비교하여 37.4%의 억제를 나타냈으나, 돌연변이형은 ACC가 없는 경우와 비교하여 6.6%만을 억제하였다. 이 결과는 피토크롬이 에틸렌 생성을 통하여 뿌리 굴중성 반응을 조절한다는 것을 제시한다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2001년도 한국생물과학협회 학술발표대회
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• pp.91-91
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• 2001

No Abstract, See Full Text

• 한국광과학회:학술대회논문집
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• 한국광과학회 2003년도 학술대회지
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• pp.86-89
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• 2003

• 한국광과학회:학술대회논문집
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• 한국광과학회 2003년도 학술대회지
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• pp.90-96
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• 2003

• Rapid Communication in Photoscience
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• 제3권3호
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• pp.53-55
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• 2014

The shade avoidance syndrome is a morphological and physiological response when plants are exposed to shade. Recent work in Arabidopsis had begun to define the molecular components of the shade avoidance syndrome in dicotyledonous model plant. However, little is known about the shade avoidance response networks in agriculturally important monocotyledon crops such as rice. Here, we found that the degree of bending at the lamina joint is inversely proportional to the R:FR ratio. To elucidate which phytochrome is involved in this response, we did lamina joint inclination assay with the rice phytochrome-deficient mutants (osphyA, osphyB, and osphyC) and the wild type plants. Whereas the osphyA and osphyC knockout mutants bent at the lamina joint in the far-red rich condition as the wild type plants, the osphyB knockout mutants no longer bent at the lamina joint in the far-red rich condition. These results suggest that PHYB acts as a sole photoreceptor in the lamina joint inclination response in rice.