title: Studies on isolated starch-containing (Vicia faba) and starch-deficient (Allium cepa) guard cell protoplasts.
abstract: Guard cell protoplasts from starch-containing Vicia faba and starch-deficient Allium cepa stomata were isolated, stabilized and recovered with an efficiency - in relation to the potential yield - of approx. 62% and 77%, respectively. In vitro, guard cell protoplasts (GCP) respond to abscisic acid and fusicoccin by respectively contracting and swelling, that is, decreasing or increasing in diameter by about 15% and more in comparison to the control. This in vitro response correlates with, but is more than 4 times as rapid as, the in vivo response of the stomata. Among the advantages presented by working with isolated GCPs are: greater sensitivity in response; freedom from influences of cuticular ridges, cell walls, subsidiary cells, and epidermal cells; and direct and parallel comparisons of starch-containing and starch-deficient GCP systems.
authors.affiliation: Institut für Botanik und Mikrobiologie der Technischen Universität München, Arcisstraße 21, D-8000, München 2, Federal Republic of Germany.
authors.forename: H
authors.initials: H
authors.lastname: Schnabl
authors.forename: C H
authors.initials: CH
authors.lastname: Bornman
authors.forename: H
authors.initials: H
authors.lastname: Ziegler