Light-induced chloroplast movements in plants

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  • 2014-01-17



Light-induced chloroplast movements in plants


- Date/Time : Tue March 18., 2003


- Speaker :  Dr. Roger P. Hangarter

             - Indiana University

- Place : Life Science Bldg. #104

- For inquires : Professor Youngsook Lee Dept. of Life Science

                생명과학과 이영숙 교수 (☎279-2296)


- Abstract

   As sessile organisms dependent on light as their sole energy source, plants have developed numerous ways to maintain optimal accessibility and use of this dynamically changing light source. Too little light impairs growth whereas too much light can damage the photosynthetic apparatus, resulting in a net decrease in photosynthesis. While a plant can do little to alter the amount of light to which it is exposed, changes in leaf and chloroplast orientation can alter the amount of light the photosynthetic machinery itself absorbs. Light-induced chloroplast movements have been observed in nearly all plants.  This response is dependent on the intensity and direction of blue light to which a plant is exposed, Typically, low-fluence rates of light cause chloroplasts to accumulate along the periclinal cell walls while high fluence rates cause chloroplasts migrate to anticlinal cell walls. It is thought that these chloroplast movements serve to maximize light capture under low light conditions while the position of the chloroplasts under high fluence rates is thought to avoid photodamage. The exact mechanism of this movement is not well understood, although the photoreceptors responsible for the response are known and the actin cytoskeleton has been shown to be required. I will discuss some of the classic experiments on light-induced chloroplast and present a progress report on the work we have been doing on several chloroplast movement mutants we have isolated using a novel mutant.