title: Clumping and dispersal of chloroplasts in succulent plants.
abstract: Plants have evolved various photoprotective mechanisms to mitigate photodamage. Here we report the diurnal movement of chloroplasts in the leaves of succulent crassulacean acid metabolism (CAM) plants under combined light and water stress. In leaves of water-stressed plants, the chloroplasts became densely clumped in one or sometimes two areas in the cytoplasm under light and dispersed during darkness. The chloroplast clumping resulted in leaf optical changes, with a decrease in absorptance and an increase in transmittance. The plant stress hormone abscisic acid induced chloroplast clumping in the leaf cells under light. We suggest that the marked chloroplast movement in these CAM plants is a photoprotective strategy used by the plants subjected to severe water stress.
authors.affiliation: Faculty of Agriculture, Meijo University, Tempaku-ku, Nagoya 468-8502, Japan.
authors.forename: Ayumu
authors.initials: A
authors.lastname: Kondo
authors.forename: Jun
authors.initials: J
authors.lastname: Kaikawa
authors.forename: Toru
authors.initials: T
authors.lastname: Funaguma
authors.forename: Osamu
authors.initials: O
authors.lastname: Ueno
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D029421:Cactaceae / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D002736:Chloroplasts / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure*; D029627:Crassulaceae / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D008854:Microscopy, Electron; D009068:Movement / Q000528:radiation effects; D018462:Photobiology; D017440:Photoperiod; D018515:Plant Leaves / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water; D000040:Abscisic Acid