Ethylene Emanation Research Articles

Effect of 1-Aminocyclopropane-1-carboxylic acid and aminoethoxyvinylglycine on ethylene emanation and somatic embryogenesis from orchardgrass leaf cultures

Ethylene emanation rates were assessed from leaf tissues of an embryogenic seed plant (Cycle 0) and regeneration cycle plants selected for enhanced embryogenesis (Cycles I, II and IV). In all experiments, ethylene was assessed from the basal 1 cm portion of the innermost leaf. Ethylene emanation was five-fold higher in Cycle II and Cycle IV plants than in Cycle 0 and nonembryogenic (NE) seed plants. After two days culture on Schenk and Hildebrandt medium containing 30 μM dicamba (SH-30), ethylene emanation from Cycle 0 and Cycle II leaf sections increased by 55-fold. Culture of leaf explants for 30 days on SH-30 containing 1 mM 1-aminocyclopropane-1-carboxylic acid (ACC) reduced the embryogenic response by 99%. Treatment of leaf explants with 1 mM aminoethoxyvinylglycine (AVG) reduced ethylene emanation but did not affect embryogenesis. The data indicate that ethylene mediated by ACC may hinder the embryogenic response from orchardgrass leaf cultures.

Auxin and ethylene regulation of diameter growth in trees.

Recent studies on the phytohormonal regulation of seasonal cell-division activity in the cambium, primary-wall radial expansion of cambial derivatives, differentiation of xylem cells, and growth of the cortex in forest trees of the north temperate zone are reviewed. Indol-3-ylacetic acid (IAA, auxin) has been characterized by combined gas chromatography-mass spectrometry (GC-MS) in the cambial region of Abies balsamea, Pinus densiflora, Pinus sylvestris and Quercus robur. All of the evidence supports the hypothesis that developing leaves and extending shoots are primary sources of IAA. The rate of ethylene emanation varies among conifer species when adjoining phloem and cambial tissues are incubated in vitro. The cambium from young cuttings of Abies balsamea produces more ethylene than that from older cuttings. Ethylene production by seven-year-old Abies balsamea cambium is substantially increased in vitro when the tissue is provided with exogenous 1-aminocyclopropane-1-carboxylic acid and IAA. In response to elevated ethylene concentrations, cortex growth is accelerated in both hardwood and conifer seedlings. Ethrel (2-chloroethylphosphonic acid) increases ray size and ray-cell number and promotes traumatic resin-canal development in xylem. In Ulmus americana, endogenous ethylene concentrations are inversely correlated with cambial activity. Ethylene decreases vessel diameter in Acer negundo, Acer platanoides and Ulmus americana. Several studies suggest that ethylene has a role in regulating reaction-wood formation in both conifers and hardwoods.

Manipulating Carnation Petal Senescence II. The Influence of Benzyladenine on Indoleacetic Acid Metabolism and Ethylene Production

Summary Indoleacetic acid (IAA)-induced senescence of isolated carnation ( Dianthus caryophyllus L. cv. Kaly) petals was delayed with the application of benzyladenine (BA). BA reduced the IAA-induced ethylene emanation and retarded the overall rate of (1- 14 C)- and (2- 14 C)-IAA metabolism. In the presence of BA the IAA-induced metabolism that did occur appeared to be largely a result of decarboxylation. It is possible that in the absence of BA, IAA was conjugated rapidly. This could, however, not be substantiated. Using the isolated petal system as a bioassay, reapplication of the major IAA metabolite did not accelerate petal senescence to the degree seen with the application of IAA.

Effect of l-aminocyclopropane-l-carboxylic acid, silver nitrate, and norbornadiene on plant regeneration from maize callus cultures

The effect of the ethylene antagonists norbornadiene and silver nitrate and the ethylene precursor l-aminocyclopropane-l-carboxylic acid (ACC) on Zea mays plant regeneration was studied. A 12-fold increase in plant regeneration, as measured by number of plants obtained per gram fresh weight from callus cultures of maize inbreds Pa91 and H99, was obtained by 250 μM norbornadiene and 100 μM silver nitrate treatments. An increase in amout of nonregenerable tissue and a 68% decrease in plant regeneration were associated with callus treated with 1 mM ACC. Ethylene emanation from 1 mM ACC treated callus reached a maximum of 170 nl g(-1) h(-1) after 3 days compared to 7 nl g(-1) h(-1) for the control. The free proline content was up to 80% lower in 1 mM ACC treated callus grown for 30 days on medium with or without 12 mM proline, respectively, as compared to each control. These studies indicate that ethylene action inhibitors such as norbornadiene and silver nitrate can be used to increase plant regeneration efficiency from maize callus cultures.

セイヨウナシ‘テ•フランス’の追熟生理及び品質における収穫日, 追熟温度及びエチレン処理の影響

The purpose of this study was to investigate the influence of harvest date, ripening temperature, and ethylene treatment on the ripening physiology and quality of ′La France′pears. Fruits were harvested on 3 dates (Oct. 14, 21, and 24, 1985), and then were held at 10°C, 15°C, and 20°C, respectively. Weight, flesh firmness, soluble solids, titratable acidity, total suger, soluble pectin, respiration and ethylene production were measured at harvest and during ripening.1. As harvest date was delayed, the climactric rise developed more rapidly. In the preclimactreric fruits at harvest (Oct. 14, and 21), the fruit reached the climacteric peak much earlier when held at 20°C than at 15°C and 10°C, while the magnitude of the peaks in both respiration rate and ethylene emanation were lower in the fruit held at 20°C than at 15°C and 10°C. This trend was striking in ethylene emanation.2. As harvest date was delayed and ripening temperature was raised, the number of days from harvest to full ripeness became short. No clear differences in eating quality of ripe fruits were found among those fruits, but the quality was reduced more rapidly in early-harvested fruits ripend at 20°C than in late-harvested fruits ripened at both 15°C and 10°C.3. As harvest date was delayed, total suger content became high and starch content became low at harvest. There were no differences in total suger content in fruits ripended at 20°C among different harvest dates.4. As harvest date was delayed, the maximum content of soluble pectin was reduced during ripening.5. Fruit treated with 500ppm ethylene for 24 hours at 20°C showed a higher rate of respiration, and became edible 3 to 4 days earlier than untreated fruit.6. Flesh firmness seems to be a useful indicator for harvest of′La France′pears, as it is related to ripening capacity.

Ethylene and 1 -Aminocyclopropane-1-Carboxylic Acid Production inflacca, a Wilty Mutant of Tomato, Subjected to Water Deficiency and Pre-treatment with Abscisic Acid

Neill, S. J., McGaw, B. A. and Horgan, R. 1986. Ethylene and 1-aminocyclopropane-l-carboxylic acid production in flacca, a wilty mutant of tomato, subjected to water deficiency and pretreatment with abscisic acid.—J. exp. Bot. 37: 535-541. Plants of Lycopersicon esculentum Mill. cv. Ailsa Craig wild type and flacca (flc) were sprayed daily with H20 or 2x 102 mol m3 abscisic acid (ABA). ABA treatment effected a partial phenotypic reversion offlc shoots; leaf areas were increased and transpiration rates decreased. Leaf expansion of wild type shoots was inhibited by ABA. Indoleacetic acid (IAA), ABA and 1-aminocyclopropane-l-carboxylic acid (ACC) concentrations were determined by combined gas chromatography-mass spectrometry using deuterium-labelled internal standards. ABA treatment for 30 d resulted in greatly elevated internal ABA levels, increasing from 10 to 4-3 and from 0-45 to 4-9 nmol g1 fr. wt. in wild type and flc leaves respectively. Endogenous IAA and ACC concentrations were much lower than those of ABA. IAA content ranged from 0 05 to 01 nmol g~1 and ACC content from 0 07 to 0-24 nmol g~ '. Ethylene emanation rates were similar for wild type and flc shoots. Wilting of detached leaves induced a substantial increase in ethylene and ACC accumulation in all plants, regardless of treatment or type. Ethylene and ACC levels were no greater in flc leaves compared to the wild type. ABA pretreatment did not prevent the wilting-induced increase in ACC and ethylene synthesis.

Production and Release of Ethylene from 1-aminocyclopropane-1-carboxylic Acid in Lemna minor L. in the Dark and at Different Carbon Dioxide Compensation Concentrations

Duckweed Lemna minor L. was used to investigate the in vivo conversion of 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene in the dark and at different CO(2) compensation concentrations. The plants were incubated in closed bottles. Various constant CO(2) concentrations in the range 50 to 1000 ppm were obtained by applying different light intensities. During the incubation on ACC-containing solution (0.01 -1000 μM) in the dark, ACC accumulated in L. minor, and no saturation of ACC uptake occurred. ACC-dependent ethylene production, on the other hand, was saturated above 10 μM ACC (equivalent to 32 μM internal ACC). V(max) was 3.18 nmol h(-1) (g fresh wt)(-1) and apparent K(m) was 8.71 μM internal ACC. In the light, CO(2) below 1000 ppm was limiting for ACC-dependent ethylene production. In the presence of 1 and 10 μM ACC, half-maximum CO(2) activity was at 114 and 163 ppm, respectively. CO(2)-stimulation was very small at 0.1 μM external ACC and virtually absent in the case of basal ethylene production. Under non-limiting CO(2), ACC-dependent ethylene production rates in the light were higher than V(max) in darkness. The mechanism of COrstimulation of ACC-dependent ethylene production in the light was elucidated by comparing rates of ACC conjugation, and ethylene synthesis, release and retention under high and low CO(2). Inhibition of ethylene retention contributed the largest portion to the enhancement of ethylene emanation from L. minor under high CO(2) observed. However, a small stimulatory effect of CO(2) on ACC conversion to ethylene was also found, while the conjugation of ACC was not significantly affected by CO(2).

Simulated Transit Vibration and Silver Thiosulfate Applications Affect Ethylene Production and Leaf Abscission of Begonia and Schefflera

Abstract Vibrations of 0.02 gravitational force (g) at 4.1 cycles per second (cps) were applied to Begonia ‘Medora’ and Schefflera arboricola (Hayata) Merrill during 6 days of simulated transit. Vibration caused leaf abscission, necrotic leaf areas, and severed stem tips. Silver thiosulfate (STS), applied as a previbration foliar spray (0, 0.28, 0.56, 1.12, mM silver), increased leaf abscission of begonias but not scheffleras during simulated transit. Ethylene emanation from stem tips of both species increased as STS concentration increased. Ethylene emanation from stem tips was not affected by vibration. During 4 weeks of simulated retail holding, STS decreased begonia leaf abscission.

スモモ果実の成熟に伴う呼吸量, エチレン発生量及びアブシジン酸含量の変化

スモモ果実の成熟に伴う呼吸量, エチレン発生量及びアブシジン酸含量の変化

The effect of light and dark periods on the production of ethylene from water-stressed wheat leaves

Light was found to inhibit substantially (i.e. up to 88%) the production of ethylene induced by water stress in excised wheat leaves and from the shoots of intact plants. The relatively small amounts of ethylene emanating fron non-stressed leaves were also inhibited by light but to a smaller degree (i.e. up to 61%). In water-stressed leaves the degree of light inhibition of ethylene production was shown to be related to the age of the leaves; the amounts of ethylene diffusing from young leaves (i.e. 6-days old) was inhibited 52% by light whereas in older leaves (i.e. 9-days old) it was inhibited by 85%. Previous studies [Wright (1979) Planta 144, 179-188 and (1980) Planta 148, 381-388] had shown that application of 6-benzyladenine (BA) to leaves a day before wilting, greatly increases the amount of ethylene diffusing from the leaves following wilting (e.g. 8-fold), and to smaller degrees do applications of indole-3-acetic acid (IAA) and gibberellic acid (GA3). On the other hand abscisic acid (ABA) treatment reduces the amount of ethylene produced. In these earlier experiments the ethylene was collected from leaves held under dark or near-dark conditions, so in the present study the activities of these growth regulators (10(-4) mol l(-1) solutions) under dark and light conditions were compared. It was found that they maintained the same relative activities on ethylene emanation (i.e. BA>IAA>GA3>water controls>ABA) under both light and dark conditions. However, because of the inhibitory effect of light, the absolute amounts of ethylene produced from all treatments were always much higher in the dark than in the light (usually about a 6-fold difference). An interesting effect of light treatment on ethylene biosynthesis was found when water-stressed leaves were kept in dark chambers for 41/2 h and then transferred to light. Quite unexpectedly, instead of the rate of ethylene production falling immediately, it continued to be produced at the dark rate (i.e. no light inhibition!) for over 2 h before the rate began to decline, and for a much longer period (i.e. in excess of 41/2 h) if the leaves had previously been sprayed with BA. Predictably, leaves placed in the light (i.e. in leaf chambers) and then transferred to darkness, immediately or very soon produced ethylene at the dark rate. One explanation of these results, which is discussed, would be that the biosynthesis of an ethylene precursor requires an obligatory dark stage. The possible implications of these studies to a survival role of ethylene in plants during periods of water stress is discussed.

Control of Lateral Bud Growth inPhaseolus vulgarisL. by Ethylene in the Apical Shoot

Elongation growth of the first trifoliate leaf axillary bud was induced by physical restriction of the apical growth or by treating the apical shoot with ethylene or ethephon. There is evidence to suggest that the promotion of axillary bud development by ethylene action on the apical shoot was associated with the availability of freely diffusible ethylene in the tissues of the treated shoot. Loss of apical dominance was not, apparently, directly dependent on either the internal ethylene concentration (i.e. concentration in the vacuum-extracted gases) or on the rate of ethylene emanation. The effects of aminoethoxyvinyl glycine (AVG) and silver nitrate on ethylene production were examined. Although treatment of the shoot with tri-iodobenzoic acid (TIBA) induced various morphological responses in the plant, including axillary bud outgrowth, which appeared similar to the responses to ethylene, the initial effect of TIBA is not thought to be ethylene-mediated.

Extraction of Endogenous Ethylene and Ethane from Leaves ofPhaseolus vulgarisL.

A procedure to recover small volumes of gases from plant tissues by vacuum extraction is described. Changes in the volume of the gases and the concentrations of ethylene and ethane recovered from Phaseolus leaves were observed when the evacuation conditions during extraction were altered. These changes were different in the primary leaves and in the second trifoliate leaves. Thus, estimates of internal ethylene and ethane concentrations appear to be influenced both by the morphology of the tissue and the evacuation conditions employed. There was a positive correlation between the concentrations of ethylene and ethane in the gaseous extracts. The internal ethylene concentrations in the primary, first trifoliate, and second trifoliate leaves, considered together, were correlated with their respective rates of ethylene emanation.

Control of Ethylene Synthesis and Action by Silver Nitrate and Rhizobitoxine in Petunia Leaf Sections Cultured in Vitro1

Abstract Pretreatment of excised leaves of Petunia hybrida L. with AgNO3 permitted shoot formation equal to the control, when explants were cultured on a medium containing 6-benzylamino purine (BA), but increased callus formation, chlorophyll content, and ethylene production. When explants were cultured on a medium containing α-naphthaleneacetic acid (NAA), pretreatment with AgNO3 promoted callus growth, root formation and extension, and ethylene production, but inhibited root hair formation. Pretreatment of explants with CuSO4 suppressed ethylene production and chlorophyll content. Inclusion of AgNO3 partially overcame the effects of CuSO4 alone. When the rhizobitoxine analog, L-2-amino-4-(2-aminoethoxy)-trans-3-butenoic acid (Rh), was used for pretreatment, ethylene emanation was inhibited for 2 or 3 weeks. Number of shoots and roots, root length, root hair and callus formation were not affected by Rh except that callus growth was reduced on a medium containing NAA. NAA (1.0 mg/liter) promoted callus and root formation and induced high levels of ethylene, while kinetin (0.2 mg/liter) stimulated shoot formation but simultaneously induced much lower levels of ethylene.

果実•野菜の成熟生理と貯蔵に関する研究 (第1報)

Physiological changes associated with the maturation of apples on the tree were investigated using three apple cultivars: Jonathan (medium maturing, short shelf life), Indo (late, intermediate shelf life), and Ralls Janet (late, long shelf life). Fruits were picked 5-13 times at weekly intervals during the maturing period, and changes in respiration (CO2 evolution), ethylene emanation, and internal ethylene concentrations were determined in relation to several criteria of maturation, such as fruit weight, titratable acidity, content of soluble solids, starch, water soluble pectin, total pectin, and firmness of flesh. The changes in amylase and pectin methyl esterase activities were also determined.1. While a climacteric rise in respiration was clearly observed during maturation on the tree in Jonathan and Indo apples, it did not occurr in Ralls Janet apples until the normal harvest period. Ralls Janet apples, however, showed a typical climacteric rise both when they were stored at 20°C, or attached to the tree, far beyond the usual harvesting time until the time when most fruits had naturally dropped.2. Internal ethylene concentration was found to increase two weeks before the climacteric onset of respiration, reaching a levels of 4ppm at the climacteric minimum in Jonathan apples. In Indo and Rails Janet apples, a range of 0.3-0.5ppm predominated from a month before the climacteric onset. A sharp increase was found almost simultaneously with the climacteric rise in Indo; in Ralls Janet, the increase occurred at the time of climacteric minimum, reaching levels of several ppm.3. Rapid increases in ethylene emanation occurred almost simultaneously with the climacteric rise in Jonathan and Indo, but only a slight increase was observed in Rails Janet even after the increase in respiration and internal ethylene concentration.4. The relationship between maturity and the change in respiration was also compared among the three. With Jonathan, maturation advanced rapidly and the fruit became edible at the climacteric minimum of respiration. Indo apples became edible after the rise of respiration; the fruits contained high levels of starch and total pectin, and their decomposition progressed slowly. With Ralls Janet, while maturation advanced slowly, the rise of respiration occurred very late, and the climacteric peak was found a month after the fruits were edible.5. Respiration rates and internal ethylene concentrations in Ralls Janet apples were much lowr than those of Jonathan and Indo apples through the pre-and post- climacteric phases. This fact seems to be related to the fact that Ralls Janet apples have a longer shelf life in comparison with the other two cultivars.

Abscission in the Tumbleweed Kochia indica: Ethylene, Cellulase, and Anatomical Structure

The transition region between the root and the stem is the site of abscission in the tumbleweed Kochia indica. A comparison of the stem, transition region, and root with regard to their rate of ethylene emanation, cellulase activity, and anatomical features showed that, prior to abscission, high rates of ethylene evolution and cellulase activity exist in the root and the transition region but not in the stem. An extended lag period of 35 days was found between the maxima of ethylene emanation and cellulase activity. Both in the root and the transition region, parenchyma is more abundant than in the stem, but in the transition region the vascular rays are interlocked and form a network of parenchymatous tissue across the organ. We suggest that ethylene induces cellulase activity, probably through intermediate steps, which in turn dissolves the walls of the parenchyma cells. In the transition region this causes abscission, while in the root this causes only softening.

Ethylene evolution during germination of different sex phenotypes of cucumber

Ethylene production by germinating seeds of cucumber during the first 4 days after imbibition was determined for different sex phenotypes. Ethylene emanation from germinating seeds of gynoecious plants was much higher than from those of the more male phenotypes of androecious, monoecious and hermaphrodite. Ethylene addition and removal (by hypobaric ventilation) during germination caused no apparent changes in subsequent sex expression of the plants. Ethylene production by single F 2 seeds was not closely associated with subsequent sex expression of the plants derived from a cross between gynoecious and androecious cucumbers. These studies suggested that ethylene production during germination was not always closely related to subsequent sex expression.

Involvement of ethylene in epinasty of CMV-infected cucumber cotyledons which exhibit increased resistance to gaseous diffusion

Infection of cucumber seedlings by cucumber mosaic virus (CMV) caused a marked epinasty of the cotyledons persisting for at least 48 h, and followed by a partial recovery. Significantly enhanced levels of endogenous ethylene were detected in CMV-infected cotyledons about 24 h before epinasty occurred. Healthy cotyledons exhibited epinasty following exposure to exogenous ethylene. Exposure of infected seedlings to hypobaric ventilation, conditions which facilitated endogenous ethylene removal, prevented epinasty. Thus, CMV-induced epinasty in cucumber cotyledons seems to be related to enhanced ethylene production. Increased leaf resistance to gaseous diffusion was found in CMV-infected cotyledons as compared with healthy ones. This seems to be the reason for the lower levels of ethylene detected in the ambient atmosphere of diseased cotyledons and these possible changes have to be taken into consideration when ethylene emanation from diseased plants is examined.

Autoinhibition of Ethylene Formation in Nonripening Stages of the Fruit of Sycomore Fig (Ficus sycomorus L.)

Differences in the mechanism of ethylene emanation of Ficus sycomorus L. during various stages of the fruit development were investigated by enclosing the figs in jars. Two distinct patterns of ethylene emanation were found. Pattern a. in stages not capable of ripening, neither spontaneously nor as a result of physiological treatment (nonripening stages A and C), ethylene concentration in the jar increased linearly for a short time and then remained constant. Pattern b. in stages capable of ripening (ripening stages B, D, and E), the linear increase in ethylene concentration continued for the entire period of measurement. In nonripening stages, ethylene emanation stopped when ethylene concentration in the jar reached a constant value (0.6 mul/l at stage C). Aeration of the figs and the jar renewed ethylene emanation. CO(2) concentration in the jar never exceeded 0.5%. Treatment of stage C figs with 0.6 to 10 mul/l exogenous ethylene caused immediate and complete cessation of ethylene emanation whereas the same treatment did not cause any change in rate of ethylene emanation from figs at the ripening stages B and D. Gashing (wounding) of stage C figs temporarily changed the pattern of ethylene emanation from pattern a to pattern b.We concluded that in the nonripening stages ethylene acts as an autoinhibitor of its own production but this does not occur in the ripening stages.

Effect of Water Stress on Ethylene Production by Detached Leaves of Valencia Orange (Citrus sinensis Osbeck)

Detached leaves of Valencia oranges, Citrus sinensis Osbeck, emanated ethylene at markedly higher rates and contained more endogenous ethylene when placed under water stress at 55% relative humidity than when placed in water-saturated air. Water stress induced defoliation from detached branches. Relieving the water stress of such leaves by transfer to a mist chamber resulted in lowering of the rates of ethylene emanation to the level occurring in leaves maintained continuously in a mist chamber. This ability to recover from the water stress was evident for only up to 10 to 20 hours of stress, when the relative turgidity of the leaves was 50 to 60%. Beyond that time the level of ethylene emanation of stressed leaves was not lowered by rehydration in a mist chamber; these overstressed leaves could not reabsorb their original water content. Ethylene emanation was in high correlation with the relative turgidity of detached leaves of oranges.

Relationship between Ethylene and the Growth of Ficus sycomorus

The relationship between ethylene and growth was investigated in Ficus sycomorus L. A marked increase in ethylene emanation preceeded all the phases of rapid growth and ripening of the syconium.Gashing of fig during the 16th to 22nd day of syconium development induced a 50-fold increase in the rate of ethylene emanation within the 1st hour, and a 2- to 3-fold increase in diameter and weight, followed by ripening within 3 days. Application of ethylene, Ethephon, and auxins caused the same effects as wounding. Since the auxin and Ethephon induced ethylene emanation, it is concluded that ethylene is mainly responsible for the marked morphological changes caused by gashing. The stage of slow growth of this fruit is characterized by slow emanation of ethylene, low sensitivity to exogenous ethylene, and no morphological responses to gashing.