The role of gibberellins A 1 and A 3 in fruit growth of Pisum sativum L. and the identification of gibberellins A 4 and A 7 in young seeds

Hormonal Control of Parthenocarpic Ovary Growth by the Apical Shoot in Pea1

“…The inability of IAA or ABA to inhibit the growth of pollinated ovaries when applied to the severed stump of decapitated plants may indicate that following pollination, these organs contain saturating levels of active GAs to counteract the inhibitory effect of IAA or ABA transported from the apical shoot. This is in agreement with the observation that the level of GA 1 (the presumed active GA) in the pod of pollinated ovaries (approximately 1.2 ng/g fresh weight) is sufficient to stimulate the maximum growth capability of the ovary, and that the presence of higher concentrations of GA 1 in the ovary (as a result of exogenous applications) does not elicit further growth (Rodrigo et al, 1997). This is probably the reason that the inhibitory effect of IAA and ABA from the apical shoot is not perceived under standard experimental conditions in the presence of developing seeds.…”

“…However, only applied GAs produce parthenocarpic fruits morphologically similar to fruits with seeds (Vercher et al, 1984;Carbonell and García-Martínez, 1985). Furthermore, the inhibition of fruit growth by inhibitors of GA biosynthesis and its reversal by applied GAs (García-Martínez et al, 1987;Santes and García-Martínez, 1995), and the correlation between the content of GAs in different tissues of fruit and the growth rate of the pod (García-Martínez et al, 1991;Rodrigo et al, 1997) suggest that GAs, probably GA 1 , are the hormones that control the development of the pericarp of seeded fruits.…”

The Genepat-2, Which Induces Natural Parthenocarpy, Alters the Gibberellin Content in Unpollinated Tomato Ovaries

“…GA 20 is the immediate precursor of GA 1 in many species (Graebe, 1987). The metabolic biosynthetic pathway of GA 1 in reproductive tomato tissues, however, is still unknown, and GA 4 as an alternative precursor, as suggested in pea fruit (Rodrigo et al, 1997), cannot be fully discarded. However, the low GA levels of members of the GA 4 biosynthetic pathway in young tomato fruit (Bohner et al, 1988;Koshioka et al, 1994) suggest that the early-13-hydroxylation pathway is the main operative pathway in the ovary and fruit (Fig.…”

Gibberellin Is Essentially Required for Carrot (Daucus carotaL.) Somatic Embryogenesis: Dynamic Regulation of Gibberellin 3-Oxidase Gene Expressions

“…[14][15][16][17][18][19][20][21][22][23] Some evidence has been accumulating that suggests GA plays in the formation and development of zygotic embryos. For instance, relatively high levels of GAs were observed in an early stage of zygotic embryos in stenospermocarpic grape 24) and maize.…”