2-chloroethane Phosphonic Acid Research Articles

Inhibition of Rb+ Absorption and Transport by Ethrel in Wheat Seedlings

The effects of different concentrations of ethrel (2-chloroethane phosphonic acid) on theabsorption and transport of Rb+ in wheat seedlings grown in low salt (0.2 mM CaCl2) or high salt (dilute nutrient) solutions were studied. The presence of ethrel (20 ppm) was found to be very inhibitory to both the absorption and transport of Rb+ during a 24 hours absorption period, in general. A time course uptake pattern revealed that the rate of inhibition increased with time. Pretreatment of the roots with ethrel (20 ppm) for 48 hours was also effective in reducing the absorption and transport particularly in seedlings grown in low salt medium. It is suggested that ethrel resembles the respiratory inhibitors in their action on ion uptake.

Effects of ethrel (2-chloroethane phosphonic acid) on sex expression in mulberry

Effects of ethrel (2-chloroethane phosphonic acid) on sex expression in mulberry

Induction of Hypocotyl Coiling in Abelmoschus esculantus Moench. by 2-chloroethane Phosphonic Acid and its Reversal by Morphactin

Induction of Hypocotyl Coiling in Abelmoschus esculantus Moench. by 2-chloroethane Phosphonic Acid and its Reversal by Morphactin

2-Chloroethanephosphonic acid reduces transpiration and stomatal opening in Coffea arabica L.

Foliar sprays of 2-chloroethanephosphonic acid reduced transpiration rates per unit leaf area and stomatal apertures during the day in Coffea arabica L. The effect was first detected six hours after treatment and persisted for up to five days.

Lettuce seed germination: Prevention of thermodormancy by 2-chloroethanephosphonic acid (ethrel)

Ethrel verhindert den Ruhezustand von «Cabbage»-Salatsamen, der durch hohe Temperaturen verursacht wird. Es wird angenommen, dass die Hemmung der Salatsamenkeimung durch hohe Temperaturen vermittelt wird, besonders durch ihre Wirkung auf die endogene Bildung des Athylens, welches eine Schlusselrolle bei der Samenkeimung spielt.

Antagonism between morphactin and ethylene in root-coiling of Ipomoea pentaphglla

Summary Ethrel (2-chloroethanephosphonic acid), an ethylene generating compound, caused extensive coiling of the main root of Impomoea pentaphylla seedlings. This effect of ethrel could be alsmost completely reversed if morphactin was added simultaneously.

Natural fruit drop and induced abscission to facilitate mechanical harvesting of Manzanillo and Souri olives

The natural drop of olive fruit, before harvest, in relation to stages of fruit development, was studied in Manzanillo olives. The absolute amount of green and half-black fruit drop was rather constant for most of the studied period. The drop of black fruit increased constantly with the advancement of maturation on both an absolute and relative basis. In studying the effect of various halogenated acetic acids on the abscission induction of Manzanillo and Souri olives, no consecutive order of activity could be found. Dichloroacetate (DCA) and monoiodoacetate (MIA) showed the highest activity. A pretreatment of Manzanillo olives with 2,4,5-chlorophenoxypropionic acid (2,4,5-TP) and chlormequat (CCC) did not affect the efficiency of various abscission-inducing chemicals. Large-scale mechanical harvesting trials with the Souri variety showed a mean increase of fruit drop up to 26% when agents such as glycerin, MIA and 2-chloroethane phosphonic acid (CEPA) were used over a period of three seasons.

Lettuce Seed Germination: Interaction between Auxin and 2-Chloroethanephosphonic acid (Ethrel)

Auxins (NAA, IAA) inhibited the seed germination of lettuce cv. Cabbage. The auxin-indueed inhibition of seed germination could be overcome if 2-chlorethanephosphonic acid (CEPA, ethrel) or kinetin was added simultaneously. Thus ethylene can also modulate the action of endogenous inhibitors in seed germination.

Stimulation of Latex Flow in Hevea Brasiliensis by 4-Amino—3,5,6-Trichloropicolinic Acid and 2-Chloroethanephosphonic Acid

Abstract Application of 4-amino—3,5,6-trichloropicolinic acid, alone or in mixtures with 2,4,5-T, gave larger and more persistent yield responses than application of 2,4,5-T alone in one experiment, but this was not confirmed in another. One morphactin was moderately effective but another was ineffective. N-dimethylamino-succinamic acid did not stimulate longer flow or give larger yields. Acetylene, ethylene, halogenoparaffins and 2-chloroethanephosphonic acid (which releases ethylene in plant tissues) were all effective in prolonging flow and increasing yields. All effective non-gaseous stimulants of latex flow seemed to have one common feature, namely, production of ethylene.

Förderung der zellproliferation unter der einwirkung von 2-chloräthylphosphorsäure bei explantaten von Begonia x richmondensis in steriler kultur

Summary The factors leading to neoformation on stem segments from partial florescences of Begonia x richmondensis are comprehended in a controlled system in vitro . Auxin, which has been proved to be indispensable in this standardized system in order to induce adventive shoots and flowers cannot be replaced by the ethylene releasing compound 2-chloroethanephosphonic acid. Hence it follows that on the one hand under standard conditions the effect ascribed to the auxin supply on the neoformation process cannot be regarded as mediated by ethylene produced in the segment tissue under the influence of IAA present in the substrate. On the other hand it follows therefrom that ethylene does not release the auxin depending processes during neoformation under standard conditions, consequently it does not interfere with the auxin metabolism. The morphogenesis during neoformation under standard conditions is inhibited in the presence of 2-CEPA (2.0 and 20.0 ppm Ethrel), or completely prevented (200.0 ppm Ethrel). On the contrary, the unorganized proliferation of cells is greatly promoted with 2.0 and 20.0 ppm Ethrel. Flowers formed under the influence of 2-CEPA are completely male as well as the flowers on the control segments; hence 2-CEPA does not change the sex expression in these experiments. Fragments of proliferating tissues on primary Begonia implants can be subcultivated when isolated. By this 2-CEPA is the first out of many other substances tested rendering possible callus growth and continued subculture over a prolonged period in a Begonia species. The growth habit of the callus tissue is not compact but very smooth due to the high tendency of cells to dissociate by decomposition of the middle lamellae as well as the increase by swelling of the separated cells without any visible signs of differentiation of tracheidal structures within cell walls.

The effect of ethrel on nodulation inPisum sativum L.

Nodulation of inoculated pea plants was severely inhibited when ethrel (2-chloroethane phosphonic acid) was applied to the roots. The inhibition was evident at ethrel concentrations of 2 ppm and above. Ethrel applied to the foliage at 10 ppm also depressed nodulation. At least part of the effect of ethrel on nodulation came from its inhibition of root growth.

Comparative Effects of Abscisic Acid and 2-chloroethanephosphonic Acid on Expansion of Isolated Cotyledons of Ipomoea pentaphylla

Summary In Ipomoea we observed that various growth retardants (CCC, B-nine and Phosfon) inhibited the expansion of isolated cotyledons while 2,4-dichloro-phenoxy acetic acid, gibberellin, cytokin ins and certain fluorene-9-carboxylic acid derivatives (morphactins) acted as stimulators of this process (1, 2). Further, gibberellin when used in combination with CCC or B-nine successfully reversed the inhibition of expansion caused by the former growth substances. In contrast, morphactin and 2,4-dichloro-phenoxyacetic acid, in combination, acted synergistically in influencing expansion. A synergism was also found to exist between morphactins and cytokinins (2). Recently, K ursanov et al., (3) have shown that in isolated cotyledons of pumpkin all the three phytohormones tested viz., 6-benzylaminopurine gibberellin and 3-indoleacetic acid can promote expansion. However, the resulting effect depended on the concentration of the particular growth regulator and on its quantitative ratio in respect to other phytohormones. These evidences apparently suggest that like many other physiological processes expansion of cotyledons is also regulated by endogenous levels of bio-regulants and their interactions.

Induction of root-coiling by 2-chloroethane phosphonic acid and its reversal by 2,3,5-triiodobenzoic acid

L'ethrel provoque l'enroulement des racines du jeuneIpomoea pentaphylla. Cet effet est completement annule par l'adjonction de TIBA.

Practical Applications of (2-Chloroethyl)Phosphonic Acid in Agricultural Production

Abstract In 1946 Kabachnik and Rossiiskaya (96) reported the chemical synthesis of “2-chloroethanephosphonic” acid and in 1963 Maynard and Swan (125) described the formation of ethylene from this compound. When (2-chloroethyl)phosphonic acid (ethephon; also variously cited as 2-chloroethanephosphonic acid, Amchem 66-329, CEPA and Ethrel® disintegrates, it releases ethylene and also chloride and phosphate ions (43, 67, 125, 196, 202) Ethephon is essentially stable in aqueous solutions below pH 4. When the presence of hydroxyl ions is increased and the pH rises above 4, disintegration of the chemical takes place. The pH of the cytoplasm of plant cells is generally greater than 4, so the plant growth activity of ethephon has been attributed primarily to its ability to release ethylene to plant tissues (14, 43, 132, 195, 196). Ethrel formulations provide a convenient way to apply ethylene without the need of gas-confining chambers.

Peroxidase and ethylene production by barley leaves infected with Erysiphe graminis f. sp. hordei

Inoculation of primary leaves of barley of differing compatibilities (types 0, 0–1, 2, 2H and 4) to race 3 of Erysiphe graminis f. sp. hordei resulted in increased peroxidase activity in all cases. An increase was usually evident within 24 h of inoculation and was accompanied by the appearance of one new major isoenzyme band after gel electrophoresis. This band was not seen in extracts of conidia of the pathogen, which contained little peroxidase. It was concluded that the increase in peroxidase was a host response to infection. Treatment of leaves with maleic hydrazide and 2-chloroethyltrimethylammonium chloride also increased peroxidase activity and stimulated the appearance of the same isoenzyme band seen after infection. Plants incubated in an ethylene-containing atmosphere, and plants sprayed with 2-chloroethane phosphonic acid showed neither quantitative nor qualitative changes in peroxidase. There was some indication that maleic hydrazide increased the resistance of susceptible plants to infection. Detached inoculated leaves containing the Ml-a and Ml-g genes for resistance (types 0 and 0–1) showed a marked peak in ethylene evolution within 24 h after inoculation, which however, was not always reproducible. Lines containing the ml-a and ml-g alleles for susceptibility did not show this peak. Later, ethylene evolution from the incompatible combinations declined to a low level while increasingly large amounts were produced by the compatible combinations. Extracts of infected leaves containing the Ml-g gene did not produce ethylene in vitro, and usually inhibited the production of ethylene from a methional/horse-radish peroxidase system. The inhibitor(s), of a low molecular weight, were heat stable but decreased in activity with time. Some evidence indicated that the inhibitor(s) may be phenols and that their changing levels might parallel the pattern of ethylene evolution from intact leaves.

Respiratory Response of Lemons to Ethylene1

Abstract Green and yellow lemons responded to ethylene treatment by a 2- to 3-fold increase in O2 uptake. Maximum rates of O2 uptake were reached some 20 hr after treatment at 25°G and both O2 and the continued presence of ethylene were required. Following removal of ethylene, O2 uptake declined in 2 days to a level approaching the rate before treatment. Upon retreatment with ethylene, the fruits again responded with a 2- to 3-fold increase in O2 uptake. Ethylene stimulated the O2 uptake of lemons in 5% and 10% O2 even though the rates of O2 uptake of these fruits were already limited by the low levels of O2. The presence of high levels of CO2 during ethylene treatment did not suppress the ethylene-induced respiratory increase. Lemons treated with ethylene at 35°C showed typical increases in O2 uptake. 2-Chloroethanephosphonic acid (Ethrel) stimulated the O2 uptake of lemons more effectively than ethylene.

Promotion of Ethylene Evolution and Fruit Abscission in the Olive by 2-Chloroethanephosphonic Acid and Cycloheximide1

Abstract Applications of 2-chloroethanephosphonic acid (Ethrel) at 2,250 ppm to olive (Olea europaea L.) trees under warm, low humidity conditions caused a considerable reduction in fruit removal force along with marked increases in leaf abscission and in ethylene evolution from both leaves and fruit. The addition of urea at 1.35% to the spray formulations caused a strong increase in ethylene production and in abscission effects. Definite cultivar differences appeared in response to Ethrel. An Auxin, NAA, blocked Ethrel activity, particularly if applied before, or simultaneously with, Ethrel. If applied 2 or 3 days after Ethrel, NAA reduced leaf abscission while maintaining fruit abscission. Rains following shortly after Ethrel application greatly reduced its activity in both ethylene production and abscission induction. Abscission effects from Ethrel were greater under warm than cool conditions. Cycloheximide at 50, 100, and 200 ppm applied during cool, humid weather caused ethylene production from olive leaves and fruits as well as a reduction in fruit removal force and an increase in leaf abscission. However, ethylene evolution and abscission effects were much less than those obtained with Ethrel.

Effects of 2-Chloroethanephosphonic acid on Flower Types and Flowering Sequences in Muskmelon1

Abstract Four concentrations of 2-chloroethanephosphonic acid (Ethrel) were applied at three stages of growth to andromonoecious, monoecious, and hermaphrodite muskmelon cultivars. Generally, Ethrel promoted female flower production and suppressed male flower initiation. Preflowering sprays, however, resulted in the production of exceptional pistillate flowers in andromonoecious and hermaphroditic cultivars, and hermaphroditic flowers in the monoecious cultivar. Appearance of the exceptional flowers generally followed, in all treated cultivars, a common pattern commencing with pistillate flowers and followed by increased frequency of hermaphrodite and male flowers. Exceptional flowers were fertile and capable of producing fruits with normal seed yield. Even though pistillate flowers developed at lower nodes on Ethrel-treated plants than on untreated plants, flower initiation was delayed, resulting in later maturity in all cultivars. Fruits on the treated plants were usually deformed, but seed yield and viability were normal.

Dual effect of 2-chloroethanephosphonic acid on vegetative grasses

Dual effect of 2-chloroethanephosphonic acid on vegetative grasses

Use of 2-Chloroethane Phosphonic Acid to Promote the Abscission and Ripening of Fruit ofCoffea ArabicaL.

SummaryFive field experiments were carried out to investigate the abscission and fruit-ripening properties of 2-chloroethane phosphonic acid (CEPA) on mature Coffea arabica growing at Ruiru, Kenya. A single application of formulation ACP-68-250 at 1400 ppm removed about 60–65% of young expanding berries between 4 and 6 days after spraying but had no significant additional effect after the 6th day. At this concentration about 10% of the leaves were also shed, but no other appendages, including open flowers and berries at other stages of development, were affected substantially. CEPA could replace hand-thinning of fruit in the first fruiting year of young trees and might subsequently be used in some areas to prevent overbearing and also to influence the annual fruiting pattern by selectively removing the products of unwanted flowerings. CEPA accelerated the onset of ripening of mature green berries; thus, in one experiment berries on trees sprayed with CEPA at 1400 ppm and 700 ppm began to ripen four and two weeks earlier, respectively, than untreated berries. The quality of the beans was unaffected. CEPA might be used to synchronize, stagger or prolong the harvest period and so increase the efficiency of hand-picking. Concentrations higher than 1400–1500 ppm were excessively phytotoxic.