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17 recordsLinked to original sources
PubMed1976

[Behavior of Ethephon residues on stone fruits and berries. 1. Ethephon residues on sweet and sour cherries].

The authors describe a gas chromatographic method for determing Ethephone residues. Studies on the residual behaviour of Ethephon on sweet cherries showed that the fruits contained 0.88, 1.45 and 1.83 p.p.m. of Ethephon after applications of 0.05, 0.075 and 0.1% Flordimex mixture, respectively. When the same doses were applied to sour cherries, the fruits contained 0.54, 1.12 and 1.44 p.p.m. of Ethephon; and the juices, 0.81, 1.36 and 1.77 p.p.m.

Chromatography, Gas↗
PubMed1976

[Residue retention of ethephon on stone fruits and berries. 2. Ethephon residues in currants and gooseberries].

Studies on the residual behaviour of Ethephon on black and red currants showed that the fruits contained on an average 0.39, 0.81, 2.2 and 0.64, 1.14, 1.04 p.p.m. of Ethephon, respectively, after application of 0.04, 0.06 and 0.08%. Flordimex mixture. When a concentration of 0.08% was applied to gooseberries, the fruits contained on an average 0.31 p.p.m. of Ethephon. The juice of black currants contained relatively larger residues.

Food Contamination↗
PubMed1976

Gas-liquid chromatographic analysis of ethephon and fenoprop residues in apples and their decline before and after harvest.

Ethephon (2-chloroethylphosphonic acid) and fenoprop (2-(2,4,5-trichlorophenoxy) propionic acid) may be determined in the same apple sample. After extraction with methanol, 2 separate methylation procedures were required to quantitatively convert each compound. Ethephon was esterified with diazomethane and analyzed by a flame photometric detector in the P-mode. Fenoprop was esterified with boron trifluoride/methanol and analyzed by electron capture gas chromatography. Average recoveries were about 95% at 0.05 ppm for both compounds. The limit of detection was 0.05 ppm for ethephon and 0.01 ppm for fenoprop in a 1 g sample. The persistence of both compounds before and after harvest was studied. Ethephon and fenoprop were applied simultaneously to apple trees at the recommended concentrations of 300 and 20 ppm, respectively. Ethephon residues averaged 1.6, 0.75, and 0.4 ppm at 2 hr, 10 days, and after washing at 13 days, respectively. The corresponding fenoprop residues were 0.70, 0.025, and 0.024 ppm.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1979

[Effect of the phosphonic acid derivatives ethephon and trichlorphon on the incorporation in vivo of (14C)-acetate into cholesterol and other lipids in rats].

The effect of the phosphonic acid derivatives Ethephon and Trichlorphon on the incorporation of 14C-labelled acetate into lipids especially cholesterol was investigated. Adult Wistar rats were fed for 7 days diets containing 50 and 500 ppm, respectively, of the phosphonic acid derivatives. Both compounds caused a significant increase of the 14C-activity in lipids of serum, liver, heart, and brain. The effect of Ethephon was significantly more intense than that of Trichlorphon. The important finding was the Ethephon-induced increase of the [14C]-acetate incorporation into cholesterol which continued across all the tissues studied.

Acetates↗
PubMed1978

[Behavior of Ethephon residues on tomatoes. Part I. Green house tomatoes].

The preparation Flordimex, which contains Ethephon (2-chloroethanephosphonic acid) as the active ingredient, is used for accelerating the ripening of tomatoes. During the years 1974--1977, tomato samples from 89 experiments were tested for Ethephon residues. The determination was performed gas chromatographically using alkali flame ionization detector as 2-chloroethanephosphonic acid dimethyl ester; the detection limit of the method was 0.01 mg/kg. The observed results must be evaluated on the basis of the permissible value (1 mg/kg) stipulated for vegetables by the Ministry of Health of the GDR. 1--2 days after the use of concentrations of 0.1%, 0.2%, 0.3% and 0.4%, respectively, the following mean residue values were found: 0.31, 0.50, 0.39 and 0.91 mg/kg, respectively, which decreased but slowly. This leads to the conclusion that formulation concentrations of more than 0.3% and applications of more than 6 1/ha should not be allowed by the Ministry. In case of repeated uses, 3-week intervals are imperative. Under the above-mentioned conditions of use, the mean residue values determined 4--5 days after application approximated 0.6 mg/kg. This period is to be regarded as a tentative waiting-period that must be respected after the treatment of glasshouse tomatoes with Flordimex.

Chromatography, Gas↗
PubMed1976

Rapid gas-liquid chromatographic method for determining residues of ethephon (2-chloroethyl phosphonic acid) in tomatoes.

A rapid method is described for the determination of the growth regulator ethephon (2-chloroethyl phosphonic acid) in tomatoes. Samples are extracted with ethyl acetate. The extract is methylated, decolorized with carbon, and analyzed by gas-liquid chromatography on a column packed with 15% QF-1/10% DC-200 on Chromosorb W (HP). A flame photometric detector is used. Recoveries from tomatoes fortified with 0.1-11.0 ppm ethephon were 78-98%. The sensitivity of this method is about 0.1 ppm.

Chromatography, Gas↗
PubMed1976

Metabolism of ethephon (2-chloroethylphosphonic acid) and related compounds in Hevea brasiliensis.

Ethephon (I) is used commercially to prolong the flow of latex from the rubber tree after tapping (Yield stimulation). The compound is applied to the bark in the region of the tapping cut and the effect on latex flow is due to the ethylene released by chemical decomposition, since gaseous ethylene itself is also a very effective stimulant. When 14C-I is applied to the bark of a young Hevea seedling, it is absorbed into the plant by processes which appear to be largely non-metabolic. Ethylene formation commences immediately at the site of application, and the gas is quickly translocated throughout the plant. Translocation of I to all parts of the plant also occurs and the accumulation of 14C in the bark above the zone of application is greater than that below. Chromatographic analysis has shown that compounds other than I remain in the plant tissue. Experiments using 14C-I have shown that detached leaves are able to convert a considerable proportion of the compound to at least twelve non-volatile acid products. One of these is a conjugate of I with an unidentified material. A major component of the products is 2-hydroxyethylphosphonic acid (II), which is itself converted to a number of compounds in leaves. The application of I to bark from mature Hevea, results in the formation of a single substance which is also a conjugate of I. Neither I nor II is effective in inducing the formation of ethylene from endogenous precursors in vegetative Hevea tissue. Ethylene is poorly metabolized by Hevea leaves and the evidence available indicates that it is unlikely that any of the compounds produced from I are metabolites of ethylene.

Autoradiography↗
PubMed1978

[Mechanism of acute toxic effects of chlorocholine chloride and 2-chloroethyl phosphonic acid (Ethephon)].

An account is given of results obtained from animal experiments that had been conducted with the view of elucidating the mechanisms underlying acute toxic action of CCC and Etephon. CCC was found to have neuromuscular blocking actions and, consequently, to lead to respiratory arrest in a situation of acute intoxication. The neuromuscular block has by all characteristics of a block by depolarisation. Acute toxicity of CCC was found to differ by species as well, which was attributable primarily to differentiated sensitivity of various species to depolarising neuromuscular blockers. The parasympathicomimetic effects of CCC were of secondary importance to acute toxicity of the compound. The toxicity of CCC could be reduced by small doses of atropine, but higher atropine doses proved to be unfavourable by aggravating respiratory paralysis. Reduction in acute CCC toxicity with concomitant administration of choline chloride was attributable to inhibition of the absorption rate of CCC. Long-term inhibition of plasma cholinesterase was recorded from rats and mice in after to oral administration of Etephon, but cholinesterases were not inhibited the erythrocytes and brain. All the cholinesterases studied, including those obtained from plasma, erythrocytes, and brain from rat and mouse, were inhibited in vitro by approximately identical Etephon concentrations. Inhibition of plasma cholinesteras was of no importance to acute toxic effects. Acid-borne corrosion was an established cause of deaths among rats and mice with acute Etephon intoxication.

Animals↗
PubMed1978

[Uptake and distribution of Camposan in rye].

Experiments for uptaking and distribution of the culm stabiliser "camposan" with the agens ethephon are very important to tell something about the dwarf behaviour of the treated plants of rye. The radioactive labelled ethephon is infiltrated through the roots, leaves and cuttings of culms. Uptaking through the roots is more complete than those about the foliar dissepiment. Otherwise uptaking through the foliar dissepiment is higher than about the leaves only. After radioautographic experiments, culmcutting-experiments and experiments with intact rye in the 5--6 leaf-stage we have found that the agens is transported acropetal in the xylem of the plants after uptaking by the roots up to 3 days. The labelled ethephon is translocated in a higher concentration in the phloem after foliar dissepiment application. The concentration of the agens decreases in the investigated plants up to the 5th day enormously (40--50% and after then slightly following the degradation to gaseous compounds. During 4 days ethephon is metabolized to about 5--15% ethylene and additional to about 18--20% carbondioxide.

Autoradiography↗
PubMed1977

Therapeutic trials in muscular dystrophy: II. Ethylene and its derivatives.

The plant growth stimulants ethylene dinitramine (EDNA) and ethylene have been reported to increase muscle regeneration. Such chemicals might therefore be of therepeutic benefit in the human muscular dystrophies. This report describes a series of experiments to reinvestigate the effects of EDNA, ethylene, and another plant-stimulating ethylene derivative, 2-chloroethylenephosphoric acid (Ethephon). EDNA and Ethephon administered two days after wounding both produced a significant increase of muscle protein synthesis seven days after the injury of normal muscle, though the increases were only 35 and 22%, respectively. The results suggested that early suppression of regeneration might explain the later increases. Ethylene administered in an identical way to that previously reported failed to increase muscle protein synthesis in murine muscular dystrophy or in wounded normal muscle. These studies suggest that treatment of human muscular dystrophies with ethylene derivatives is unlikely to prove of value.

Animals↗
PubMed2026

Sex-specific ethylene responses drive floral sexual plasticity in Cannabis sativa.

Cannabis sativa L. exhibits pronounced sexual plasticity in which both XX and XY plants can undergo floral phenotypic sex reversal in response to ethylene modulation, yet the underlying molecular mechanisms remain poorly defined. Here, we present the most extensive multi-omic analysis of ethylene-induced sex change in C. sativa to date, integrating over 130 RNA-seq libraries, ethylene pathway metabolite quantification, and whole-genome sequencing across three XX and XY genotypes. Treatments with silver thiosulfate and ethephon induced more than 80% phenotypic conversion, but transcriptomic responses diverged sharply between XX and XY plants. Profiling 47 ERGs revealed 14 high-confidence candidates, including CsACS1, CsACO5, CsERF1, and CsMTN, with sex-specific and temporal expression patterns that show dynamic ethylene mediation of plasticity. Early transcriptional activation occurred prior to the emergence of flowers, within 18 h of sex-change treatments and the photoperiod-induced transition to flowering. As opposite-sex floral tissues emerged, ethylene-related gene expression shifted accordingly within developing floral organs, with distinct sets of genes stabilizing the opposite-sex phenotype in XX and XY plants. Several candidates were located in non-recombining regions of the X chromosome or were absent from the Y chromosome, and most exhibited low nucleotide diversity, consistent with functional constraint. These results provide a high-resolution view of ethylene-responsive sexual plasticity in cannabis and show that the shared capacity for sex reversal in XX and XY plants is implemented through distinct regulatory trajectories that produce opposite-sex floral phenotypes. This work expands the mechanistic understanding of sex expression in dioecious species and identifies candidate genes relevant to the development of sex-stable cultivars.

Ethylenes↗
PubMed1977

Repression of asexual embryogenesis in vitro by some plant growth regulators.

A factor that represses asexual embryogenesis has been observed in the Rutaceae, with particularly high concentrations in the naturally monoembryonic cultivars. This investigation was an initial step towards identifying the factor. Citrus reticulata Blanco Ponkan mandarin nucellus explants and Daucus carota L. 'Queen Anne's Lace' callus were employed to examine effects of known plant growth regulators and to determine possible identity of one or more of them with the repressive factor. The chalazal halves of ovules of C. media L. 'Citron of Commerce' were used as control repressor source. Embryo initiation and growth of both test tissues were depressed markedly by 2,4-D, abscisic acid and ethephon. Slight inhibitions were obtained with IAA, kinetin and gibberellic acid. Recovery from the repressor did not occur readily in Citrus nucellus following recultures in citron-ovule-free medium; carrot callus resumed normal embryogenesis immediately upon transfer to suppressor-free medium. The repression by natural sources apparently involved the combined action of some or all natural hormones that are generically related to the above.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1992

Characterization of a shoot-specific, GA3- and ABA-regulated gene from tomato.

A tomato (Lycopersicon esculentum) gene (GAST1) that encodes an RNA whose abundance increases > 20-fold in shoots of the GA-deficient gib1 mutant following spraying with GA3 has been characterized. An increase in GAST1 RNA levels is detectable 2 h after treatment and levels continue to increase for at least an additional 10 h. Between 12 and 24 h following treatment, the amount of GAST1 RNA begins to decline and at 48 h the level is nearly equivalent to that of water-treated control plants. Nuclear runoff analysis indicates that 8 h after treatment with GA3, transcription of the GAST1 gene has increased only threefold, suggesting that GA acts both transcriptionally and post-transcriptionally. ABA partially inhibits the GA-mediated increase in GAST1 RNA abundance while ethephon, kinetin, and 2,4-D have little effect. GAST1 RNA is detectable in untreated leaves, stems, petioles and flowers, but not in roots. The GAST1 gene encodes a 0.7 kb transcript. The sequence of the GAST1 cDNA and genomic clones indicates that the gene is interrupted by three introns and potentially encodes a 112 amino acid protein of unknown function.

Abscisic Acid↗
PubMed1992

Molecular cloning and characterization of a gene encoding pea cytosolic ascorbate peroxidase.

A gene encoding cytosolic ascorbate peroxidase (ApxI) from pea (Pisum sativum L.) was isolated and its nucleotide sequence determined. By homologous alignment between the ApxI cDNA (Mittler, R., and Zilinskas, B. (1991) FEBS Lett. 289, 257-259) and the genomic clone, positions of introns and exons were determined. The isolated ApxI gene was found to contain 9 introns, the first of which was located within the 5'-untranslated region of the mRNA. Southern blot analysis of pea genomic DNA suggests that in pea cytosolic ascorbate peroxidase is encoded by a single copy gene. Steady state ApxI transcript levels were found to increase in response to several stresses imposed by drought, heat, and application of ethephon, abscisic acid, and the superoxide-generating agent paraquat. Increases in ascorbate peroxidase activity in response to stresses were less marked than changes observed in transcript levels; cytosolic ascorbate peroxidase protein levels measured by immunoblot analysis remained unchanged.

Amino Acid Sequence↗