Abstract
The reorganization of thylakoid membranes of Arabidopsis thaliana during growth was reported at this annual meeting last year. We report here a similar morphological alteration in the thylakoid that occurs reversibly depending on light intensity. Three light conditions of 50-60(++), 25-30(+), 110-130(+++) μmol m-2sec-1 were set up. After having been grown in (++) light for 4 weeks, some plants were placed in (+), then back to (++). Through this management, the structure of thylakoid membranes was changed from "linear" to "curly", then back to "linear". The "curly" thylakoid is also observed in leaves of 8-10 week old plants grown under the (++) condition. When these plants were moved from (++) to (+++), and then back to (++), a fluctuation in the opposite direction, from "curly" to "linear" then back to "curly" was observed. Both types of photo-stimulated alterations were accompanied by a change in the chlorophyll a/b ratio.
