photonasty

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photonasty

(ˈfəʊtəʊˌnæstɪ)
n, pl -ties
(Botany) a nastic movement in response to a change in light intensity
ˌphotoˈnastic adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

photonasty

the tendency in certain plant species to respond to light by developing sufficient cellular force or growth on one side of an axis to change the form or position of the axis, as in the opening and closing of the flowers of four-o’clocks. Cf. thermonasty.photonastic. adj.
See also: Plants
-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.
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[PGE.sub.1] at concentrations of [10.sup.-4] to [10.sup.-6] M increased the rate of both scotonastic and photonastic leaflet movements.
(1984) tested the effects of two other inhibitors of PG biosynthesis - namely, salicylic and acetylsalicylic acids - on the scotonastic and photonastic leaflet movements of Cassia fasciculata, with similar results to those obtained with the previously tested inhibitors indomethacin and phenylbutazone.
The results indicate that the compounds tested (prostaglandins and precursors) can act directly on cell membrane permeability in view of their effects on the increased rate of the scotonastic and photonastic leaflet movements.