Article au complet
Source:
http://beheco.oxfordjournals.org/content/24/4/789.full
Figure 1
A putative model of a mechanism
underlying sound production in plants. Plant cells vibrate as a result
of the active movement
of organelles within the cell (i.e., cytoplasmic
streaming; orange arrows in panel B). Cytoplasmic streaming is caused by
the activity of motor protein myosins as they slide
along actin filaments using the hydrolysis energy of adenosine
triphosphate
(panel C). As the nanomechanical motion generated
within a cell reflects the unique metabolic status of that cell, this information
is contained in the emitted vibrational wave.
Vibrations from individual cells propagate through the medium as sound
waves
and reach neighboring cells; if the receiving cells
are receptive to that particular frequency, they will also start
vibrating
proportionally to the intensity of the received
signal and when all the cells are “in tune,” the signal is amplified
(panel
D). As the signal extends outside the leaf or root
of the plant, it conveys information about that plant to neighboring
plants
or other organism (panel A).
In conclusion, a considerable body of evidence emerging from contemporary research in the plant sciences is increasingly recognizing plants as highly sensitive organisms that perceive, assess, interact, and even facilitate each other by actively acquiring information from their environment (Karban 2008; Baluška 2009; Trewavas 2009). We now know, for example, that when attacked, plants “cry for help” by producing volatiles that attract carnivorous enemies of the attacking herbivores (Dicke 2009); and on the other hand, parasitic plants can recognize their prey at a distance and evaluate their nutritional value before deciding to invade them (Kelly 1992; Koch et al. 2004). Considering that these are only a very few examples of what plants do, the Aristotelian view of plants as automata-like passive and insensitive creatures seems to be no longer accurate. By relinquishing this out-of-date view of the plant world, I hope the ideas and questions presented here seduce the most enquiring aspect of our nature into exploring the world of plants in its full potential complexity.
