Translocation and Persistence of 1,2‐¹⁴C‐(2‐Chloroethyl)‐phosphonic Acid (Ethephon) in Thompson Seedless Grapes

Abstract

Applications of 1,2−14C‐(2‐chloroethyl)phosphonic acid (ethephon) were made to the surface of mature Vitis vinifera cv. Thompson Seedless berries. After 7 days, 62 % of the recovered radioactivity was still on the outside surface and was easily washed off. Within the berry, radioactivity was present only in the carbon‐labeled ethephon fraction, as revealed by chromatographic analysis. Similar results were obtained when the compound was injected directly into the berries. Application of ethephon to the first leaf above the cluster, or to a berry pedicel or a peduncle, failed to result in measurable movement of the compound into the berries. Autoradiographic studies with young shoots indicated that ethephon translocated in the phloem in a source to sink relationship.

Effect of pollination and fertilization on the expression of genes related to floral transition, hormone synthesis and berry development in grapevine

“…The IPT gene encodes the enzyme ISOPENTENYL TRANSFERASE, which catalyzes the ratelimiting step in CK biosynthesis (Akiyoshi et al, 1984). In grapes, exogenous application of synthetic CKs is effective in increasing fruit set and ovary growth (Weaver et al, 1972;Zepeda et al, 2006), especially when applied during early stages of development. We isolated an IPT homologous gene from grapevine (Genbank accession number GQ981408), which is more similar to IPT3 from A. thaliana.…”

The Fate of 1,2‐14C‐(Chloroethyl) Phosphonic Acid (Ethephon) in Olive (Olea europea)

“…1973), and peach fruit (Abdel‐Gawad et al 1973, Lavee and Martin 1974a,b). In several other cases no metabolites could be detected (Yamaguchi et al 1971, Edgerton and Hatch 1972, Martin et al 1972, Weaver et al 1972, Puech and Crane 1975, Young and Jahn 1975).…”

Uptake and Fate of Ethephon ([2-Chloroethyl]phosphonic Acid) in Dormant Weed Seeds

“…This suggests that ethephon was partially excluded from the seed tissues. Previous studies have shown that the uptake of ethephon applied to plant surfaces is very limited (8,13 was confirmed in a similar fashion: aliquots were placed in flasks containing concentrated HCl to liberate the ethylene complexed with mercury (15) and, after purging the solutions overnight with hydrocarbon free air, the radioactivity remaining in solution was not significantly different from background levels. More than 65% of the total radioactivity recovered was in the form of carbon-labeled ethephon/ethylene.…”