Further effects of vomifoliol on stomatal aperture and on the germination of lettuce and the growth of cucumber seedlings.

(+)-Vomifoliol was shown to be as rapidly acting as (±) abscissic acid in stomatal closure time studies which involved the use of Eichhornia crassipes (Mart) Solms epidermal strips. (±)-Vomifoliol was shown to be less effective, while 4-(1-hydroxy-4-keto-2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one) had only a slight effect in the same bioassay system. (+)-Vomifoliol showed no significant effect on the germination of lettuce seeds or the growth of cucumber seedlings.

The effect of vomifoliol on stomatal aperture.

Vomifoliol, a compound related to abscisic acid (ABA) but lacking the 2,4-pentadiene sidechain and so far found in four different plant families, caused as much stomatal closure in epidermal strips of Eichhornia crassipes (Mart.) Solms as ABA at identical concentrations. It appears worthwhile to investigate whether vomifoliol plays a role as an endogenous regulator of stomatal aperture.