The influence of surfactants on transpiration of strawberry leaves

摘要

Surfactants introduced into strawberry (Fragaria grandifloraDuch. cv. Redgauntlet) leaves in doses of 5.5ensp;times;ensp;10minus;4ndash; 5.5ensp;times;ensp;10minus;2ensp;mu;mol per leaf blade decreased the transpiration rate of treated leaves regardless of the electrical charge brought to the membranes. A 5.5ensp;times;ensp;10minus;2ensp;mu;mol dose of surfactants applied during constant illumination caused almost the same decrease in transpiration as a dose of 7.5ensp;times;ensp;10minus;4ensp;mu;mol of abscisic acid. Surfactants also accelerated the decrease in transpiration in plants grown in the dark, and there was a consistent rate of solute efflux from guard cells. Fusicoccin applied to plants under the influence of surfactants or abscisic acid caused a sustained increase in the transpiration rate. Mannitol and sucrose caused a temporary increase in transpiration rate. KCl increased transpiration when applied after abscisic acid but decreased transpiration when applied after surfactants. These observations suggest that surfactants and abscisic acid influence the guard cell membrane in different ways and that the electrical charge introduced on the plasmalemma surface is not essential in the regulation of stomatal aperture.Key words: abscisic acid, strawberry, surfactants, transpiration.