Hormonal Control of Flower Bud Dormancy in Sour Cherry (Prunus cerasus L.). III. Effects of Leaves, Defoliation and Temperature on Levels of Abscisic Acid in Flower Primordia1

cis, trans-Abscisic acid (ABA) was identified by combined gas chromatography-mass spectrometry (GC-MS) in a partially purified methanol extract of mature seeds of peach (Prunus persica (L.) Batsch). No germination of intact seeds occurred during seed maturation. Germination of excised embryos increased with maturity, but ABA content of embryonic axes and other seed parts was not related to germination potential. Drying and storage of seeds increased both free and bound ABA in the embryonic axes, but did not significantly affect ABA content of other seed portions. Free and bound ABA decreased on imbibition except for free ABA in the seed coat and bound ABA in the embryonic axis, Levels of free and bound ABA paralleled one another, suggesting that although the former may be converted to the latter, bound ABA is not a major source of free ABA.

Section: Discussionsupporting

confidence: 82%

Abscisic Acid Levels in Seeds of Peach. I. Changes during Maturation and Storage1

Bonamy

Dennis

1977

“…Defoliation. Mechanical defoliation of sour cherry (Prunus cerasus L.) trees in early autumn prevents the subsequent rise in ABA content of flower primordia (11,12). On the supposi tion that the leaf might be the source of ABA in the seed, 'Golden Delicious' branches about 10 cm in diam at the base were defoliated on July 30, 1974, when the embryos had reached ca.…”

Section: Methodsmentioning

confidence: 99%

“…The supernatant was filtered through paper and evaporated under vacuum at 40°. The residue was dissolved in 25 ml phosphate buffer, pH 7.3, which was processed (11) to give neutral hexane and ethyl acetate fractions, together with acidic and bound ethyl acetate fractions. The acidic and bound fractions were evaporated, and the residues were analyzed for ABA as described below.…”

Section: Methodsmentioning

confidence: 99%

Abscisic Acid and Apple Seed Dormancy1

Dennis

1977

c,t-Abscisic acid (ABA) was identified in methanol extracts of mature apple (Malus domestica Borkh.) seeds by gas chromatography-mass spectrometry, and concentrations of both free and base-hydrolyzable (bound) ABA in immature and mature seeds were quantified by electron capture gas chromatography. Immature embryos failed to germinate regardless of time of sampling unless seed coats were removed. Germination of excised embryos reached a maximum in early August, then gradually declined to nil in mid-September. Although ABA content of the embryonic axes rose sharply at maturity, the rise occurred only after germination capacity declined. Premature defoliation reduced ABA content of the axes, but did not prevent the induction of embryo dormancy. ABA content of mature seeds declined during stratification at both 5° and 20°C, with maximum differences occurring in the embryonic axis, but dormancy was broken only at 5°. Induction of secondary dormancy by high temperature (27°) was accompanied by a slight decline in ABA content of whole seeds.

“…The passage of temperate zone deciduous trees into and out of dormancy and rest generally is attributed to phytohormones, including both growth promoters and inhibitors (4,13,14,17,20,24,25). Correlations between rest intensity and inhibitor levels, particularly ABA, have been found, but ABA is not always effective in prolonging dormancy; nor are high ABA levels always required for deep rest (7,9,14,17,20,22,25).…”

mentioning

confidence: 99%

The Role of Bud Scales in the Dormancy of Apples

Swartz

Geyer

Powell

et al. 1984

Removal of bud scales hastened bud burst of several early and late blooming apple cultivars. Descaling was most effective during the onset and end of rest. During deep rest, bud scale removal was effective only when applied 2 weeks before forcing conditions. Extracts of bud scales inhibited apple bud break in vitro. Abscisic acid (ABA) may have been responsible for part or all of this bioactivity, since ABA occurred in bud scale diffusates and could replace or reinforce the bud scales in vitro. Wound-produced ethylene was not involved in the bud scale removal response.