Endogenous abscisic acid in relation to photoperiodically induced bud dormancy.

The abscisic acid contents of birch, maple and sycamore plants growing under long and short photoperiods were measured by gas-liquid chromatography. No increase was observed in the abscisic acid content of extracts when plants were transferred to dormancy-inducing conditions.

The identification and quantitative analysis of abscisic acid in plant extracts by gas-liquid chromatography.

New techniques are described which permit the quantitative analysis of microgram quantities of abscisic acid in plant extracts by gas chromatography. Presumptive methyl abscisate peaks on gas chromatograms are positively identified by photosensitised isomerisation to methyl 2-trans-abscisate. Losses of abscisic acid during pre-purification are corrected by using 2-trans-abscisic acid as an internal standard.