The Relationship between Flower Abortion and Endogenous Auxin Content of Rose Shoots

Abstract

The amount of endogenous growth substances in stem, flowers and leaves of rose plants grown under different temperature and light conditions has been determined.It appeared to be two main growth promoting factors in the acidic fraction of the ether extract. One of them is assumed to be an auxin, probably indol-3yl-acetic acid (IAA); the other is not identified. The level of auxin was much higher in extracts from shoots grown at high temperature than in shoots grown at low temperature. Increasing light intensity also seemed to increase the auxin content of the shoots. Shoots which developed after a high cut back of the rose stem had a higher auxin content than shoots which developed after a low cut back.These findings are discussed in relation to the effect of temperature, light intensity and cut back practise on blind shoot formation in roses. The result of these investigations strongly indicate that abortion in roses is promoted by a low auxin level in the shoots.

Pleiotropic effects of the male sterile33 (ms33) mutation in Arabidopsis are associated with modifications in endogenous gibberellins, indole-3-acetic acid and abscisic acid

“…Auxins have been shown to have a role in flower development and in petal growth (Moe 1971;Kopecewicz et al 1979). Applied ABA is known to induce male sterility in some species (reviewed in Sawhney and Shukla 1994) and a male-sterile mutant in tomato contains high ABA content (Singh and Sawhney 1998).…”

Flower Bud Atrophy in Baccara Roses

“…A neutral inhibitor which is not ABA was recently found in other plants (Bittner et al 1971, Kumar and Wareing 1974, Taylor and Burden 1972, Tompsett and Schwabe 1974, Goldschmidt et al, 1973. The process of fiower atrophy in roses begins in the early stages of fiower development, with the differentiation of the sepals and petals (Hubbell 1934a, Moe 1971a. After differentiation of these organs is completed, there is no abortion in roses (Moe 1971a).…”

“…The process of fiower atrophy in roses begins in the early stages of fiower development, with the differentiation of the sepals and petals (Hubbell 1934a, Moe 1971a. After differentiation of these organs is completed, there is no abortion in roses (Moe 1971a). The various fiower organs can serve as a source of different growth substances, such as auxins (Lang 1965) and gibberellins (Jeffcoat et al 1969, Jeffcoat and Cockshull 1972, Jones and Phillips 1966, Sircar et al 1970.…”

“…The atrophy of the terminal fiower bud and its abscission is termed "blindness". It is a common phenomenon in roses and has been described in detail (Hubbell 1934a, Moe 1971a, Zieslin and Halevy 1975a. It develops gradually, and begins after the differentiation of the sepals and petals (Hubbell 1934a).…”

“…As a consequence of this, abortive, non-fiowering shoots are formed. These shoots remain short and thin, and bear fewer leaves than do the fiowering shoots (Moe 1971a). The two types of shoots differ in color due to the different pigment content of the leaves (Zieslin and Halevy 1975a).…”