Poster: Plants Interacting with Other Organisms

Abs # P19066: Does Nyctinasty Facilitate the Hunting of Herbivores by Nocturnal Carnivores?

Presenter:	Minorsky, Peter V       Contact Presenter
Authors	Minorsky, Peter  V (A)
Affiliations:	(A): Mercy College

The leaves of many plants undergo daily movements in orientation (nyctinasty). During the day the leaves assume a horizontal position that optimizes their ability to capture sunlight for photosynthesis. In the evening, the position that the leaves assume, regardless of whether they bend upwards or downwards, is essentially vertical. Such nyctinastic or sleep movements are often but not always controlled by a circadian rhythm, and it is the circadian aspect of nyctinasty as well as the underlying signal transduction mechanisms underlying such movements that have engendered the most interest from researchers. Surprisingly, much less attention has been paid to the function of nyctinasty. Here, the idea is presented that nyctinastic leaf movements constitute an indirect plant defense against nocturnal herbivores. Terrestrial carnivores generally use auditory, olfactory and visual senses to detect prey. It is hypothesized that the vertical orientation of the blades of nyctinastic plants at night would be especially beneficial to those predators such as owls and gleaning bats whose modus operandi is death from above. It is easy to imagine that the movements of prey beneath a plant with collapsed foliage would be more visually obvious to an aerial predator at dusk or on a moonlit night. Similarly, an aerial predator could much easier detect any sound made by a prey without baffling layers of foliage overhead to damp and disperse the sound. Finally, any odor released by the prey would diffuse more directly to the awaiting sensory apparatus of the predator.