Rapid adjustment of guard-cell abscisic Acid levels to current leaf-water status.
Detached broad bean (Vicia faba L.) leaflets were water stressed; within 15 minutes, guard-cell abscisic acid (ABA) concentration increased ninefold. This result eliminates the apparent discrepancy raised by reports of no correlation between initial water-stress effects on stomata and leaf ABA concentration. Six hours after stress relief, guard-cell ABA concentration was near the prestress value, which would seem to implicate other factors in stress aftereffects on stomata.
Harris
M J
MJ
Department of Biological Science (B-157), Florida State University, Tallahassee, Florida 32306-3050.
Outlaw
W H
WH