Effect of Light on Root Growth and Gravitropic Response of Phytochrome Mutants of Arabidopsis

국문 초록 (Abstract)

빛이 굴중성과 뿌리 생장에 미치는 영향을 알아보기 위해 Arabidopsis phytochrome mutant를 이용하여 뿌리생장과 굴중성 반응을 측정하였다. PhyA의 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 phyAB는 white light와 red light에서 키웠을 때 뿌리 생장이 가장 많이 억제되었다. PhyA의 굴중성 반응은 far-red light에서 키웠을 때를 제외하고 모든 빛 조건에서 키웠을 때 WT와 비교하여 촉진되었다. 한편 phyAB는 모든 조건에서 모두 굴중성 반응이 억제
되었다. Ethylene 생합성을 조절하는 효소인 ACS transcript 수준은 white light와 red light에서 키웠을 때 phyA가 높게 나타났으며, far-red light에서 키웠을 때는 phyA의 transcript 수준이 억제되었다. 결론적으로 뿌리 생장과 굴중성 반응은 phyB의 Pfr에 의해 조절된다.

다국어 초록 (Multilingual Abstract)

Light, one of the environmental stimuli, is fundamental to the growth and development of plants. Red and far-red light are sensed using the phytochrome family of plant photoreceptors. To investigate the effect of light on root growth and gravitropism, we used the Arabidopsis phytochrome mutants grown in several light conditions. The root growth of phyA reared in all light conditions except white light and was stimulated compared to the WT. The stimulation of root growth was obvious in phyA grown in red light. On the other hand, the root growth of phyB grown in all light conditions decreased, and the lowest rate of decrease was observed in phyAB grown in white and red light. The gravitropic response of phyA was stimulated compared to the WT when it was grown in all light conditions except far-red light. PhyAB grown in all light conditions showed the inhibition of gravitropic response. The transcript level of ACS, one of the enzymes regulating ethylene biosynthesis, increased in phyA grown in white and red light, but not in phyA grown in far-red light. In conclusion, these results suggested that the Pfr form of phyB regulates the root growth and gravitropism.

목차 (Table of Contents)

• 서론
• 재료 및 방법
• 결과 및 고찰
• 감사의 글
• References
• 초록

참고문헌 (Reference)

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