Auxin in scapes, flower buds, flowers, and fruits of daffodil (Narcissus pseudonarcissus L.)

Abstract

Diffusates from flower buds, flower fruits, and scape segments, and extracts of flower stalks of Narcissus pseudonarcissus contain an auxin active in the Avena geo-curvature test. The auxin behaved like indole-3-acetic acid (IAA) in thin-layer chromatography (TLC) with neutral and basic solvents on different adsorbents. After TLC, the auxin of the extracts showed chromogenic reactions identical with those of IAA; in gas-liquid chromatography on two different columns, the purified substance, after methylation, appeared at the retention time of IAA methyl ester. The auxin content of the extracts has been estimated to be equivalent to ca. 10 μg IAA kg(-1) fresh weight. Diffusates, collected at the basal end of excised flowering apices and of scape segments at different developmental stages, showed highest auxin activity when collected from old buds and young flowers, and from the basal, rapidly elongating scape regions. The diffusible auxin obtained from scape segments was very likely produced by the segments themselves. Thus, the shoot of Narcissus appears to possess two different sites of auxin production, namely, the apical region represented by the flower bud, the flower or the fruit, and the scape.

Endogenous Auxin Profile in the Christmas Rose (Helleborus niger L.) Flower and Fruit: Free and Amide Conjugated IAA

“…5). A similar effect of flower stalk growth inhibition upon bud decapitation or emasculation was observed in the miniature Cymbidium orchid (Ohno and Kako 1991), the tulip (Hanks and Rees 1977;Saniewski and De Munk 1981), and the daffodil (Edelbluth and Kaldewey 1976;Hanks and Rees 1977).…”

“…It was observed that removal of the flower or floral organs inhibits the elongation of the floral stalk or peduncle (Op den Kelder and others 1971;Hanks and Rees 1977). Treatment of emasculated or decapitated flowers with auxins (Edelbluth and Kaldewey 1976;Hanks and Rees 1977;De Munk 1979;Kohji and others 1979;Saniewski and De Munk 1981;Ohno and Kako 1991), as well as treatments of isolated stalk explants (Gabryszewska and Saniewski 1983), led to the conclusion that these plant hormones originating in anthers, gynoecium, or developing fruit are largely responsible for peduncle elongation. Identification of endogenous hormones during flowering in the tulip (Okubo and Uemoto 1985;Xu and others 2008) and barley (Wolbang and others 2004) confirm that diffusible auxins from floral organs, in the first place, and in coordination with gibberellins are responsible for stalk elongation.…”

Roles of Floral Organs and Phytohormones in Flower Stalk Elongation of Cymbidium(Orchidaceae).

“…This phytohormone is supplied from flower buds whose development is stimulated by GA3, or by low temperature. The supply of auxin by the developing flower buds was also noted in other plants (3,7,13). The effectiveness of GA on flower stalk elongation is different among plant species.…”

Modern Chromatographic Methods for the Identification and Quantification of Plant Growth Regulators and Their Application to Studies of the Changes in Hormonal Substances in Winter Wheat During Acclimation to Cold Stress Conditions

“…This ester is readily detected in the GC-column effluent by a flame ionization detector (FID), which is the most widely used detector system because it has sensitivity limits approaching 1 ng for almost all organic compounds. This ester was used in the identification of IAA in maize seeds (Powell, 1964), in tobacco shoots (Bayer, 1969), and in flower buds, flowers, and fruits of daffodil (Edelbluth and Kaldewey, 1976), where identification was based on co-chromatography with authentic Me-IAA and spectrophotofluorimetry. Me-IAA was also employed for identifying IAA in maize roots (Elliott and Greenwood, 1974) and in shoots of Douglass fir (DeYoe and Zaerr, 1976) using GC-l1S procedures.…”