|Authors: ||Y. Desjardins, J.-F. Dubuc, A. Badr|
|Keywords: ||microarray, acclimatization, exogenous sugars, reactive oxygen species, oxidative stress, GABA, nitrogen|
Plants cultured in vitro are subject to variable amount of stress, that is, the culture environment continuously imposes unfavorable conditions, which alter the physiology and morphology of plantlets.
For instance, plant tissue culture in vitro causes mechanical injuries, wounding, osmotic shock (partly due to high sucrose content in the medium), nitrogen toxicity (due to high N content in medium) hormonal imbalances, and gas toxicities (high ethylene), just to name a few.
In order to survive and grow in this difficult environment, plantlets have to acclimatize to these unusual conditions; they modify their steady-state physiology to adapt to their external environment.
This acclimation process affects many biochemical and genetic processes, which manifest themselves through epigenetic modifications of plant development and alteration of metabolism.
Based on our recent studies of gene expression using microarray analysis and metabolomic, we demonstrate that tissue culture is perceived as a stress by the plantlets, which respond by activating a number of systemic defense mechanisms and developmental responses.
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