Level of Abscisic Acid in Integuments, Nucellus, Endosperm, and Embryo of Peach Seeds (Prunus persica L. cv Springcrest) during Development

Abstract

Free abscisic acid (ABA) in integuments, nucellus, endosperm, and embryo was determined throughout seed development of peach (Prunus persica L. cv Springcrest). Quantification of ABA was performed using combined high performance liquid chromatography-radioimmunoassay based on a monoclonal antibody raised against free (S)-ABA. In the integuments and endosperm, ABA concentration remained constant during the first 100 days after anthesis and rose in the following days when fresh weight was rapidly decreasing. In the nucellus, the ABA concentration variation pattern paralleled that of tissue growth. ABA concentration in the embryo increased constantly with the growth of the tissues to reach a maximum at the last growth stage. The role of ABA in peach seeds is discussed in relation to the development of the different seed tissues.Growth of the peach fruit occurs in three stages, as shown by Connors (4): rapid growth (stage I), delayed growth (stage II), and second rapid growth (stage III). The growth of the nucellus and integuments during stage I is parallel to the rapid growth ofthe pericarp, while embryo development is arrested. At the beginning of stage II (delayed development of the pericarp), the nucellus and integuments enter a period of delayed development, and the endosperm begins a rapid enlargement. During stage III, the nucellus degenerates and the embryo begins its development; depending on the variety, it reaches maximum size during this period.The endogenous systems that regulate this growth pattern are not known, but several scientists have described a regulating role played by hormones. A high content of gibberellins has been observed during peach seed development (6,17,18). Ethylene production also occurs at relatively high rates and, at the same time, 1 -aminocyclopropane-1 -carboxylic acid concentration peaks in the fruit (8, 10). Auxin level is also high during seed development, as shown by Miller et al. (1 1). Few data are available on ABA content in peach seeds (2) and particularly on ABA quantification in the various seed components during development.The availability of immunological methods for the quantification of ABA allows accurate analysis of ABA content over a great number of samples in much less time compared with the more traditional gas-chromatographic analysis. In fact, ABA content in the various tissues during seed development has been thoroughly measured in recent investigations carried out on Sechium edule (15) and Phaseolus coccineus (12).In this paper, we report on the quantitation of ABA in integuments, nucellus, endosperms, and embryos of Prunus persica cv Springcrest during seed development, with the aim of extending information on the hormonal relation between these seed components. MATERIALS AND METHODS Plant MaterialDeveloping fruits of peach (Prunus persica cv Springcrest), were harvested in the open field from May to June 1990. Care was taken to spread the sampling over the trees so that it would not drastically alter the crop load of any tree. Fruits were open...

Anatomical and biochemical studies in persisting and shedding seeds during the development of peach fruits

“…The HPLC experiments showed the presence of immunoreactive material in the fraction with the same elution volume as ABA and in other fractions, indicating the presence of immunoreactive compounds other than ABA in crude aqueous extracts of all the seeds under investigation, as found by PIAGGESI et al (1991) in peach seed tissues of Prunus persica cv Springcrest. In order to verify whether these compounds could originate from ABA during the 16-h extraction period, [14C]-ABA was added to the tissue prior to extraction.…”

“…Each stage is characterized by anatomical and morphological changes in seed tissues (OGNJANOV et al, 1995). Hormonal activity plays an important role in regulatory mechanisms of fruit growth (GIANFAGNA & RACHMIED, 1986;MILLER et aL, 1987MILLER et aL, , 1988PIAGGESI et aL, 1991). During this period, competition for carbohydrates, fia and between fruits and vegetative organs of trees, is very strong (DE JONG & GOUDRIAAN, 1989; GENARD & BRUCHOU, 1993).…”

Efecto de la temperatura, medios de cultivo y reguladores de crecimiento en la germinación de embriones cigóticos de durazno (Prunus pérsica) var. Diamante

“…Las semillas de durazno, como de muchas otras especies del género Prunus acumulan grandes cantidades de ácido abscísico (ABA) en la cubierta seminal, cotiledones y en el mismo embrión, principalmente durante la última etapa del desarrollo de la semilla [15]. Por esta razón, las semillas requieren un periodo de frío de entre 10 a 12 semanas para romper la dormancia y permitir la germinación, período en el cual se sintetiza ácido giberélico (GA) que promueve e incrementa la actividad enzimática en el embrión, mientras que la concentración de ABA se reduce [8].…”

Influence of exogenous abscisic acid on germination and plantlet conversion frequencies of hybrid larch somatic embryos (Larix � leptoeuropaea)

“…Therefore, we confirm the ABA identity of the compound quantitated in larch embryo samples . (±)ABAGE fraction still lack identification in our samples, but a similarly fractionated immuno- reactive compound using the same kind of HPLC column was found in embryos of peach seeds [21] . These authors also still lack ABAGE identification .…”