Lack of ethylene involvement in tulip tepal abscission

Abstract

The tepals of cut flowers of Tulipa hybrida cv. Golden Apeldoorn and Tulipa kaufmanniana cv. Shakespeare abscise 3–4 days after harvest. The weakening of the abscission zones is accompanied by cell wall breakdown and the separation of 3–4 rows of intact cells at the base of the tepal. During senescence, there is no ethylene climacteric and ethylene production rates remain low, between 0.07 and 0.4 nl g−1 fresh weight h−1. Adding 3–5 μl l−1 ethylene slightly accelerated the weakening of the abscission zones but had no effect on the time of first abscission. Neither 0.5 mM silver thiosulphate nor 5 mM aminoethoxyvinylglycine delayed the time to abscission. It is concluded that tulip tepal fall does not involve primary regulation by ethylene, unlike the majority of other abscission systems that have been studied.

Cloning and characterization of ACC oxidase genes from tulip

“…These major accumulations of ACO transcripts at the start of flower senescence have also been observed in LeACO3 of tomato (Barry et al 1996) and petunia (Tang et al 1994). In previous study, tulip was thought as an ethylene-insensitive species because the flowers produce only a small amount of ethylene during flower senescence and exogenous ethylene have no effect on abscission (Sexton et al 2000). However, the observation of gene expressions of TgACO1 and TgACO3 suggested that the ethylene may participate to the flower development and senescence.…”

“…Therefore, it has been concluded that tulip petal senescence may not be primarily regulated by ethylene (Sexton et al 2000). To clarify the molecular mechanism of ethylene synthesis through the flower senescence of tulips, we tried to isolate the ACO gene; genomic organization and expression analysis of the ACO gene were studied.…”

Aroma production from cut sweet pea flowers (Lathyrus odoratus): the role of ethylene

“…Gland counts were made using alcohol fixed petal tissue viewed over a 0.5‐cm 2 grid that had been ruled on to a light microscope slide. Material for scanning electron microscopy was viewed directly after freezing in liquid nitrogen (Sexton et al 2000). To study the exudate from the glands on the scented petals the liquid was drawn by capillarity from the gland heads into glass microelectrodes (PUL‐1 World Precision Instruments, Sarasota, FL) under a light microscope.…”

“…The period over which cut flowers produce aroma should be increased by the use of ethylene antagonists or transgenic plants which either can not synthesize ethylene or which can not respond to it. However, just as ethylene is not universally involved in regulating petal senescence (Sexton et al 2000) it may not necessarily regulate aroma decline in all cut flowers.…”

Molecular Changes Occurring during Acquisition of Abscission Competence following Auxin Depletion in Mirabilis jalapa

“…Similarly, a lack of an ethylene requirement in abscission has also been shown for tulip (Tulipa kaufmanniana; Sexton et al, 2000), cocoa (Theobroma cacao; Aneja et al, 1999), and orchid (Cymbidium spp. ; Van Doorn, 2002) flowers, although ethylene in these systems has been demonstrated to accelerate abscission.…”