Effect Of 2-chloroethylphosphonic Acid Research Articles

Effect of 2-chloroethylphosphonic acid and vanillin on chlorophyll, protein and RNA synthesis in detached cucumber cotyledons, and chlorophyll degradation in senescing leaf discs of kale

N<sup>6</sup>-benzylaminopurine (BAP) and KC1 stimulated growth in detached greening cucumber cotyledons; BAP enhanced RNA synthesis whereas KCl strikingly accelerated leucine-<sup>14</sup>C incorporation into proteins. Vanillin (0.01 M) inhibited greening and protein synthesis, and nullified the stimulatory effects of KC1. a-chloroethylphosphonic acid (CEPA, 0.01 M) inhibited greening without any effect on protein synthesis when it was applied alone; CEPA decreased RNA synthesis, completely nullified the K<sup>+</sup>-induced synthesis of chlorophyll, and reduced the BAP<sup>-</sup> or KCl<sup>-</sup>induced growth. Vanillin inhibited yellowing in 'senescing leaf discs of kale kept in darkness, whereas CEPA had an opposite effect.

On the use of Ethephon as abscising agent in cv. Crimson Seedless table grape production: Combination of Fruit Detachment Force, Fruit Drop and metabolomics

The effect of 2-chloroethylphosphonic acid (Ethephon, in the following ETH) as abscising agent on cv. Crimson Seedless table grape was investigated by means of Fruit Detachment Force (FDF) and Fruit Drop (FD) analyses combined with a metabolomic study carried out by High Resolution Mass Spectrometry (HRMS) and Nuclear Magnetic Resonance (NMR) spectroscopy. The effectiveness of ETH as abscising agent was ascertained with ETH concentration ranging from 1.4 to 4.0g/L in a two-year study. The ETH treatments caused berry drops higher than 40% and induced an increase of tartaric acid, procyanidin P2, terpenoid derivatives and peonidin-3-glucoside as well as a decrease of catechin and epicatechin. HRMS–NMR covariance analysis was carried out to correlate the fluctuations of tartaric acid NMR signals to those of MS peaks of the secondary metabolites affected by ETH treatments.

<b>Germination and biochemical changes in ‘Formosa’ papaya seeds treated with plant hormones

This study aimed to investigate the effects of growth regulators on germination rates and biochemical compound concentrations in Carica papaya L. seeds ('Formosa' group). The seeds were harvested from fruits at maturation stages 3 and 5 (50 and 75% yellow fruit skin, respectively). The effects of 2-chloroethylphosphonic acid (CEPA), KNO3 and gibberellic acid (GA3) on seed germination, germination index speed, soluble sugars, starch, lipids, soluble proteins and total proteins of the papaya seeds were evaluated. The seeds from stage 5 showed a higher rate of germination 30 days after sowing than did the seeds from stage 3. Treatment with CEPA decreased seed germination, apparently due to decreased starch mobilization; the opposite response was observed following KNO3 treatment. GA3, alone or in combination with KNO3, stimulated an increase in lipid mobilization. In general, with the exception of CEPA, all growth regulators tested were effective in overcoming seed dormancy, and KNO3 was the most effective. The seeds from stage 3 fruits treated with KNO3 or KNO3 + GA3 had higher rates of germination at 14 days.

Effects of ethephon and 1-methylcyclopropene on fruit ripening and the biosynthesis of volatiles in oriental sweet melon (Cucumis melo var. makuwa Makino)

SummaryThe effects of 2-chloroethyl phosphonic acid (ethephon) and 1-methylcyclopropene (1-MCP) on the production of aroma volatile compounds, aroma-related enzyme activities, and the rate of respiration were investigated in two cultivars of oriental sweet melon [Cucumis melo var. makuwa Makino ‘Caihong 7’ (highly aromatic) and ‘Tianbao’ (less aromatic)] during storage at room temperature (approx. 23ºC). Ethylene production and the rates of respiration in fruit were enhanced by ethephon treatment, while decreased by 1-MCP. Ethephon advanced the onset of the climacteric peak of ethylene evolution and CO2 production in ‘Tianbao’ fruit. Moreover, emission of the characteristic aroma compounds identified in both cultivars were dependent on ethylene, showing an increase in response to ethephon treatment, and a strong reduction in response to 1-MCP treatment. Volatile esters predominated in both cultivars, among which acetic esters were the most abundant. Ethephon appeared to result in a preferential regulation of the levels of esters and alcohols in oriental sweet melon. Different levels of esters, alcohols, and aldehydes had a combined effect on the diversity of flavours in both cultivars. Lipoxygenase, alcohol dehydrogenase, and alcohol acyltransferase had a combined effect on the content and variety of aroma volatiles measured. The activities of these three enzymes showed positive regulation by ethylene.

Effect of 2-Chloroethylphosphonic Acid (Ethephon) on the Endogenous Levels of Gibberellin-Like Substances and Abscisic Acid in Buds and Developing Shoots of Three Grape Varieties

Dormant buds and young developing shoots from grapevines sprayed with ethephon in the fall to hasten defoliation were analyzed for gibberellin-like substances and free and bound abscisic acid (ABA). The treatments which resulted in delayed budbreak had no effect on free gibberellic acid (GA) level but enhanced ABA and bound-GA syntheses. The presence of ABA in bud extracts, which depressed α-amylase activity in the barley endosperm bioassay, was confirmed by gas chromatography.

RESPONSE OF JERUSALEM CHERRY TO GROWTH REGULATORS

Effects of 2-chloroethyl phosphonic acid (ethephon), N6-benzyladenine (BA) and indoleacetic acid (IAA) were studied on branching, plant growth and fruit development of Jerusalem cherry (Solanum pseudocapsicum L.). Ethephon increased first order lateral branching, and number of leaves and fruits, and promoted maturity while it decreased fruit diameter and shoot and fruit fresh and dry weights. BA enhanced first order lateral branch and leaf numbers but reduced fruit number and size. IAA had no significant effect on most measured characters.

Cinetique d'action de l'acide 2-chloro ethylphosphonique sur les polyribosomes du latex d' Hevea brasiliensis

Effects of 2-chloroethylphosphonic acid on the latex of Hevea brasiliensis were studied during 7 days after its application on the tapping panel of the tree. Ribosome polymerisation shows a dramatic rise within 12 hr after treatment. This shift is overcome at first without rRNA synthesis. Increase of latex production and latex pH exhibit similar features and start 24 hr after application of the, stimulant. After 4 days, rRNA concentration and the stability of the lutoïds (microvacuoles with lysosomal characteristics) change significantly.

Effect of 2-Chloroethylphosphonic Acid (CEPA) on the Distribution of Growth Regulators in Geotropically Stimulated Vicia faba Roots

Summary In a recent study on Vicia faba roots kept horizontal for 30 min, it was found the concentration of gibberellins to be considerably higher in the upper than in the lower halves of the geotropically stimulated roots, whereas abscisic acid (ABA) attained a higher concentration in the lower than in the upper halves, and thus showed a distribution pattern similar to that usually reported for indoleacetic acid (IAA). In the present investigation the effect of ethylene pretreatment of the roots on the distribution of these growth regulators during subsequent geotropic stimulation was determined. Ethylene treatment was effected by immersing the intact seedling in a solution of 2-chloroethylphosphonic acid (CEPA) at 200 mg/l at pH 6.0 for 1 h prior to stimulation. The contents of both IAA and ABA were determined by wheat coleoptile section assay of purified extracts of the root-halves, whereas gibberellins was determined by lettuce hypocotyl bioassay. As expected the establishment of an asymmetrical distribution of IAA was prevented by the CEPA treatment. Gibberellins and ABA, on the other hand, were distributed as in stimulated roots not pretreated with CEPA. In spite of the presence of an excess of gibberellins in the upper and of ABA in the lower halves, the CEPA-pretreated roots failed to develop geotropic curvatures within 4 h. These results, therefore, provide no evidence for a participation of gibberellins or ABA in the early development of geotropic curvatures in these roots. Some roots of intact seedlings were treated with 100 mg/l (pH 6.0) solution of GA3, ABA, kinetin or IAA for 1 h prior to geotropic stimulation. Both in untreated and GA2,-and ABA-treated samples, 90 to 100% of the roots developed positive geotropic curvatures within 2 h. Since the flooding with GA3 or ABA, assumed to prevent the establishment of an effective transversel gradient by saturating the transport system, did not prevent the development of the curvatures, these results agree with the above conclusion. On the other hand, flooding with kinetin or IAA at 100 mg/l prevented the development of the positive curvatures. Pretreatment with kinetin or IAA at 10 and 50 mgμl did not completely prevent the geotropic reaction but delayed it for several hours.

Flowering in Pisum: Effect of 2-Chloroethylphosphonic Acid and Indole-3-Acetic Acid

The flowering node of an early line of peas (genotype lf e sn hr) was delayed by Ethrel (active agent 2-chloroethylphosphonic acid) in concentrations as low as 1 p.p.m. The delay of 3.7 nodes obtained with 40 p.p.m. is one of the largest reported for any chemical treatment of peas. Indole-3-acetic acid also caused a significant delay when applied at the high rate of 1 mg per plant. We suggest that the delay in both cases may be mediated by ethylene.

The Hormone Content of Ripening Grape Berries and the Effects of Growth Substance Treatments

Berries on field-grown Vitis vinifera cv. Doradillo were treated at different times during stage II with benzothiazole-2-oxyacetic acid or 2-chloroethylphosphonic acid, and measurements were made of their growth and hormone content. The concentration of ethylene was low during stage II and declined as berries ripened. Both 2-chloroethylphosphonic acid and benzothiazole-2-oxyacetic acid caused increases in ethylene concentration, yet they had varying effects on ripening: the former applied at the start of stage II and the latter applied 1 week before the end of stage II delayed ripening, while 2-chloroethylphosphonic acid applied at the end of stage II hastened ripening.The abscisic acid content of berries increased as they ripened, and the effects of 2-chloroethylphosphonic acid and benzothiazole-2-oxyacetic acid on abscisic acid levels were correlated with the effect of these compounds on ripening. The roles of abscisic acid and ethylene in the regulation of the ripening of grapes are discussed.

Effects of 2-Chloroethylphosphonic Acid on Growth, Plastid Pigments, and Sucrose Translocation in Radish

2-Chloroethylphosphonic acid (CEPA) caused a significant decline in chlorophyll content of radish plant within 5 d of treatment. Such effects were greater when plants were treated at the two- than at the four-leaf stage. In early treated plants, concentration of CEPA increasing from 20 mg/1 progressively increased leaf weight, while decreasing root (radish) weight. A concentration of 10 mg/1, applied at the three-leaf stage, increased leaf and root weights by 27 and 30 per cent respectively in the cultivar ‘Cavalier’. Similar responses were obtained with the cultivar ‘Cherry Belle’. While Cavalier showed a discrete 10 mg/1 optimum, ‘Cherry Belle’ exhibited a range of concentrations (10-40 mg/1) optimal for growth. At relatively high concentrations, early application of CEPA caused inverse changes in sucrose-14C in the leaves and the root, so that decreased retention by leaves was accompanied by increased transport to roots. Low concentrations of CEPA appear promising for growth stimulation in root-crop plants.

Potentiation and Inhibition of the Effects of 2-Chloroethylphosphonic Acid by Malformin

Malformin completely inhibited Ethrel-induced swelling and fresh weight increase on the basal stem portion of Phaseolus vulgaris L. cuttings, but markedly potentiated Ethrel- or ethylene-induced abscission. With regard to abscission, malformin reacted synergistically with ethylene and dark aging, and in a manner which appeared to differ from that of ethylene and dark aging. The numerous effects of malformin on plant growth and development cannot be explained in simple terms of enhanced ethylene production.

The Effect of 2-Chloroethylphosphonic Acid on Dicamba Translocation in Wild Garlic

Foliar applications of 2-chloroethylphosphonic acid (CEPA) 7 days prior to spot applications of14C-labelled 3,6-dichloro-o-anisic acid (dicamba) to leaves of wild garlic (Allium vinealeL.) increased basipetal translocation of the dicamba as measured 7 days after dicamba treatment. High concentrations of CEPA were inhibitory. The ethylene released from CEPA degradation may have altered the metabolic “sink-source” relationships within the wild garlic plants allowing increased basipetal translocation of subsequent applications of dicamba when low concentrations of CEPA were applied.

Effect of 2-chloroethylphosphonic acid on enzyme induction in barley endosperm

The effect of 2-chloroethylphosphonic acid (CEPA) on GA induction of α-amylase in the barley endosperm test was studied. No amylolytic activity could be detected when CEPA was substituted for GA. When CEPA was added simultaneously with GA it inhibited GA induction of α-amylase. Inhibition increased as increasing concentrations of CEPA were added. This inhibition is partially due to a direct influence of CEPA on the enzyme-starch reaction.

Sex Expression in Cucumber Plants as Affected by 2-Chloroethylphosphonic Acid, Ethylene, and Growth Regulators

The effects of 2-chloroethylphosphonic acid (Ethrel), ethylene, and some growth retardants on sex expression of cucumber plants (Cucumis sativus L.) were investigated, with the use of a monoecious cultivar (Improved Long Green) which has a strong tendency toward maleness.Ethrel caused increased femaleness when applied at 50 milligrams per liter at the first to the third leaf stage, but when applied at the cotyledon stage it was ineffective. The later the time of application, the higher the node at which the first female flower appeared. The total number of female flowers was about the same regardless of application time. A mixture of gibberellins A(4) and A(7) caused maleness, and Ethrel caused femaleness. However, when applied in combination at the first leaf stage the interaction was not significant. It seems, therefore, that Ethrel and gibberellins are not antagonistic but rather have different sites of action, although they have opposing effects on sex expression.Ethylene caused femaleness but was far less effective than Ethrel. Alar (N-dimethylaminosuccinamic acid), CCC((2-chloroethyl)trimethylammonium chloride), Phosphon D(2, 4-dichlorobenzyl-tributylphosphonium chloride), and abscisic acid did not affect sex expression of cucumber.

Effect of 2-Chloroethylphosphonic Acid on Sex Expression and Yield in Butternut Squash and its Usefulness in Producing Hybrid Squash1

Abstract Ethrel, 250 ppm, applied at 9 weekly intervals, starting when the first true leaf was about 1 inch in diam. produced 91% pistillate flowers, increased fruit numbers, and decreased fruit wt of ‘New Hampshire Butternut’ squash. Plant spread was reduced under this treatment due to a shortening of in tern ode length. Treatments of 0, 50, 100, 250, and 500 ppm of Ethrel applied once did not change significantly the no. of pistillate flowers on a whole plant basis. The total fruit yield did not differ among treatments. Ethrel could be used to develop a female line of ‘New Hampshire Butternut’ as an aid in the development of F1 hybrids having low crookneck frequency.

Effect of 2-Chloroethylphosphonic Acid and Cycloheximide on Abscission and Ripening of ‘Bartlett’ Pears1

Abstract Branch units of 20 ‘Bartlett’ pear trees were sprayed with 2-chloroethylphosphonic acid (Ethrel) at 250, 500, or 1000 ppm or with cycloheximide (beta-[2-(3,5-dimethyl-2-oxocyclohexyl)-2-hydroxyethyl] glutarimide) at 3, 5, or 20 ppm a wk before the beginning of normal harvest to weaken the abscission layer to facilitate mechanical harvest. Half the trees had been sprayed with naphthaleneacetic acid (NAA) to prevent preharvest drop. Nine days after application, Ethrel at 1000 ppm had significantly reduced the fruit removal force (FRF) on trees that had received no NAA. In contrast, the presence of NAA evidently nullified the abscission-promoting effect of Ethrel. All other treatments failed to reduce FRF significantly. None of the sprays caused discernible phytotoxic effects or hastened fruit maturity. However, after storage for 50 days at 0°C, 17% to 50% of the fruits that received Ethrel at 500 or 1000 ppm, broke down during ripening. Cycloheximide caused no breakdown, but 20% to 80% of the fruits aprayed with 5 or 20 ppm had necrotic spots at the calyx end.

Effect of 2-Chloroethylphosphonic Acid on Sex Expression and Yield in Butternut Squash and its Usefulness in Producing Hybrid Squash1

Abstract Ethrel, 250 ppm, applied at 9 weekly intervals, starting when the first true leaf was about 1 inch in diam. produced 91% pistillate flowers, increased fruit numbers, and decreased fruit wt of ‘New Hampshire Butternut’ squash. Plant spread was reduced under this treatment due to a shortening of in tern ode length. Treatments of 0, 50, 100, 250, and 500 ppm of Ethrel applied once did not change significantly the no. of pistillate flowers on a whole plant basis. The total fruit yield did not differ among treatments. Ethrel could be used to develop a female line of ‘New Hampshire Butternut’ as an aid in the development of F1 hybrids having low crookneck frequency.

Effect of 2-Chloroethylphosphonic Acid and Cycloheximide on Abscission and Ripening of ‘Bartlett’ Pears1

Abstract Branch units of 20 ‘Bartlett’ pear trees were sprayed with 2-chloroethylphosphonic acid (Ethrel) at 250, 500, or 1000 ppm or with cycloheximide (beta-[2-(3,5-dimethyl-2-oxocyclohexyl)-2-hydroxyethyl] glutarimide) at 3, 5, or 20 ppm a wk before the beginning of normal harvest to weaken the abscission layer to facilitate mechanical harvest. Half the trees had been sprayed with naphthaleneacetic acid (NAA) to prevent preharvest drop. Nine days after application, Ethrel at 1000 ppm had significantly reduced the fruit removal force (FRF) on trees that had received no NAA. In contrast, the presence of NAA evidently nullified the abscission-promoting effect of Ethrel. All other treatments failed to reduce FRF significantly. None of the sprays caused discernible phytotoxic effects or hastened fruit maturity. However, after storage for 50 days at 0°C, 17% to 50% of the fruits that received Ethrel at 500 or 1000 ppm, broke down during ripening. Cycloheximide caused no breakdown, but 20% to 80% of the fruits aprayed with 5 or 20 ppm had necrotic spots at the calyx end.

Effect of 2-chloroethylphosphonic acid and gibberellic acid on survival of tall and dwarf peas grown in root rot soils

Seeds of peas, Pisum sativum L. varieties Alaska and Early June, were soaked for 3 hours in 2.3 × 10−3 M 2-chloroethylphosphonic acid (CEPA) or 3 × 10−5 M gibberellic acid (GA3), sown in steamed or root rot soils, and grown to flowering stage at controlled soil temperatures with 14 hours per day of 32 000 lumens per square meter. CEPA delayed emergence and decreased survival in var. Alaska, but increased survival in var. Early June between 14 C and 18 C. GA3 decreased survival in both varieties. Early emergence was followed by increased wilting. CEPA showed antigibberellin activity, in most instances counteracting the adverse effects of GA3.