CALCIUM-DEPENDENT STORAGE RETRIEVAL OF ENVIRONMENTAL SIGNALS IN PLANTDEVELOPMENT/

Natural stimuli (e.g. wind, rain, touching, wounding) have the potenti al to affect plant morphogenesis, usually by inhibiting growth. We sho w here, to our knowledge for the first time that very mild, non-injuri ous environmental stimuli induce a signal responsible for initiation o f meristem formation in the hypocotyl epidermis of intact flax seedlin gs. This signal can be recorded and stored in the plant without being expressed until recalled by a second signal resulting from calcium dep letion. A 4-day separation between signals does not result in an appar ent loss in the magnitude of the response. Information storage might b e the basal mechanism allowing a plant to integrate the large set of e nvironmental stimuli received under natural conditions, thus making it possible to optimize its developmental responses to these stimuli.