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A diurnal movement of plant parts, such as the opening during the day and closing during the night of certain flowers.

[Greek nux, nukt-, night; see nekw-t- in Indo-European roots + -nasty.]

nyc′ti·nas′tic (-tĭk) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Botany) botany a nastic movement, such as the closing of petals, that occurs in response to the alternation of day and night
[C20: from Greek nukt-, nux night + -nasty]
ˌnyctiˈnastic adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
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Keywords: Heliotropism, LC-MS/MS, nyctinasty, proteomics, soybean.
Other nastic responses include thermonasty, as in the opening and closing response of tulips due to fluctuations in temperature; nyctinasty, the so-called sleep movements of leaves due to changes of turgor of certain cells located at the base of the petiole; and seismonasty, a response to shaking or some other mechanical disturbance.
Phytochrome controlled nyctinasty in Albizzia julibrissin.