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

Abstract

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.

Organogenesis from Immature Pecan Embryonic Axes in Vitro

“…The decreasing levels of ABA, as documented by Wood (1984), and the increasing competency of the embryonic axis up to the latter third of the sampling period, correlate with this concept; however, despite a continued decline in A B A , there is a concom itant decrease in morphogenesis-the opposite to what one would predict. These results parallel the observations of Bonamy and Dennis (1977) in peach seed. These investigators were unable to demonstrate a clear relationship between ABA content and metabolic competency in terms of germination potential of peach embryos.…”

Abscisic Acid Levels in Seeds of Peach. II. Effects of Stratification Temperature1

“…Residues from the acidic dichloromethane fraction (free ABA) and a similar fraction after base hydrolysis of the water residue (bound ABA) were methylated with diazomethane, and aliquots were gas chromatographed using an electron capture detector (2). Two replicate samples of 50 seeds each were used in all cases.…”

“…Lipe and Crane (6) noted a decline in an ABA-like inhibitor during after-ripening of peach seeds, and demonstrated that both this inhibitor and synthetic ABA could inhibit the germination of non-dormant peach embryos. Wong (10) and Bonamy and Dennis (2) have identified ABA in extracts of dormant peach seeds, and Wong (10) measured the levels of an ABA-like inhibitor during stratification at 3° and 20°C. The inhibitor content of seed coats and cotyledons was not significantly affected by stratification at either temp, while that of embryonic axes declined markedly regardless of temp.…”