scholarly journals Heat treatment effects on ACC oxidase activity of 'Keitt' mangoes

2003 ◽  
Vol 15 (3) ◽  
pp. 145-148 ◽  
Author(s):  
Renar João Bender ◽  
Eduardo Seibert ◽  
Jeffrey K. Brecht
Keyword(s):  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Hot Water ◽  
In Vitro Activity ◽  
Ethylene Dibromide ◽  
Heat Treated ◽  
Physical Treatments ◽  
Water Treatments

With the use of ethylene dibromide for mango disinfestation being ruled out, vapor heat or hot water treatments are the only alternatives for quarantine treatments of mangoes. Physical treatments such as heat treatments have been implicated in higher incidence of physiological disorders and enhancement of ripening processes. Therefore, the objective of the present work was to determine the effects of hot water treatments on ethylene production and on the in vitro activity of ACC oxidase. Cv. Keitt mangoes were immersed for 3 min in hot water at 53 °C or 90 min in water at 46 °C. Immediately after the treatments, some of the mangoes were analyzed for ACC oxidase activity and others were stored to be analyzed after 4 days at 12 °C. There was a significant increase in the ACC oxidase activity just after the hot water treatments. After 4 days, only the mangoes treated for 90 min maintained high ethylene production and ACC oxidase activity. Tissue from the outer layers of the mesocarp had higher enzyme activity compared to tissues from the innermost layers of the mesocarp of heat-treated mangoes.

Ecotypic differences in rhythmicity of ethylene production in Stellaria longipes: the possible roles of ACC, MACC, and ACC oxidase

1997 ◽  
Vol 75 (7) ◽  
pp. 1027-1033 ◽  
Author(s):  
R. J. N. Emery ◽  
A. Kathiresan ◽  
D. M. Reid ◽  
C. C. Chinnappa
Keyword(s):  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Spatial Separation ◽  
Growth Cycle ◽  
Daily Rhythm ◽  
Stellaria Longipes ◽  
Response To Stress

The alpine tundra ecotype of Stellaria longipes is characterized by a dwarf phenotype, whereas the prairie ecotype can be semidwarf or highly elongated depending on its environment. Related to their ability to elongate, these ecotypes also show divergent abilities to produce and respond to ethylene. The prairie ecotype produces a strong daily rhythm of ethylene, which is maintained even following stress events such as wind. The alpine ecotype exhibits a much less pronounced rhythm but greatly increases ethylene production in response to stress. We investigated what differences in ethylene synthesis might be responsible for the ability of the prairie ecotype to produce a large and regular daily rhythm of ethylene production, which in the alpine ecotype is weaker or sometimes absent. Levels of the immediate precursor to ethylene, 1-aminocyclopropane-1-carboxylate (ACC), and its major conjugate, malonyl ACC (MACC) showed no rhythm across the course of a day. Moreover ACC levels remained stable during an entire growth cycle (21 days) in the prairie ecotype, even though ethylene is known to increase especially during periods of rapid elongation. By contrast, assays of ACC oxidase performed in vivo and in vitro showed rhythms of activity similar to those of ethylene production observed in the prairie ecotype. However, the levels of ethylene produced in the ACC oxidase assays were considerably higher than levels of ethylene normally produced by unstressed plants, and the rhythm of ACC oxidase activity was observed in both ecotypes, despite the fact that alpine Stellaria longipes exhibits a less pronounced ethylene rhythm. Thus, we concluded that although ACC oxidase activity may partially account for rhythmic production of ethylene in prairie ecotypes, other controlling factors such as spatial separation of ACC from ACC oxidase should be investigated. Key words: ACC oxidase, ecotypes, ethylene, phenotypic plasticity, rhythmicity, Stellaria longipes.

scholarly journals 24-Epibrasinolide Modulates the Vase Life of Lisianthus Cut Flowers by Modulating ACC Oxidase Enzyme Activity and Physiological Responses

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 995
Author(s):  
Mohammad Darvish ◽  
Habib Shirzad ◽  
Mohammadreza Asghari ◽  
Parviz Noruzi ◽  
Abolfazl Alirezalu ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Water Absorption ◽  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Postharvest Quality ◽  
Vase Life ◽  
Dependent Manner ◽  
Cut Flowers ◽  
Oxidase Enzyme

Ethylene is the most important factor playing roles in senescence and deterioration of harvested crops including cut flowers. Brassinosteroids (BRs), as natural phytohormones, have been reported to differently modulate ethylene production and related senescence processes in different crops. This study was carried out to determine the effects of different levels of 24-epibrassinolide (EBL) on ACC oxidase enzyme activity, the final enzyme in ethylene biosynthesis pathway, vase life, and senescence rate in lisianthus cut flowers. Harvested flowers were treated with EBL (at 0, 3, 6, and 9 µmol/L) and kept at 25 °C for 15 days. The ACC oxidase activity, water absorption, malondialdehyde (MDA) production and vase solution absorption rates, chlorophyll and anthocyanin contents, and the vase life of the flowers were evaluated during and at the end of storage. EBL at 3 µmol/L significantly (p ≤ 0.01) enhanced the flower vase life by decreasing the ACC oxidase activity, MDA production and senescence rates, and enhancing chlorophyll and anthocyanin biosynthesis and accumulation, relative water content, and vase solution absorption rates. By increasing the concentration, EBL negatively affected the flower vase life and postharvest quality probably via enhancing the ACC oxidase enzyme activity and subsequent ethylene production. EBL at 6 and 9 µmol/L and in a concentration dependent manner, enhanced the ACC oxidase activity and MDA production rate and decreased chlorophyll and anthocyanin accumulation and water absorption rate. The results indicate that the effects of brassinosteroids on ethylene production and physiology of lisianthus cut flowers is highly dose dependent.

Harvest maturity related changes in the cold-induced activation of 1-aminocyclopropane-1-carboxylic acid metabolism in Granny Smith apples / Efecto del estado de madurez sobre la activación por frío del metabolismo del ácido 1-aminociclopropano-1-carboxílico en manzanas Granny Smith

1999 ◽  
Vol 5 (3) ◽  
pp. 223-228 ◽  
Author(s):  
C. Larrigaudiere ◽  
I. Recasens ◽  
J. Graell ◽  
M. Vendrell
Keyword(s):  
Carboxylic Acid ◽  
Ethylene Production ◽  
Oxidase Activity ◽  
Acid Metabolism ◽  
Cold Treatment ◽  
Acc Oxidase ◽  
Malus Domestica Borkh ◽  
Harvest Dates ◽  
Harmonization Process ◽  
Harvest Maturity

Changes in 1-aminocyclopropane-1-carboxylic acid metabolism in apples ( Malus domestica Borkh cv Granny Smith) were studied in relation to cold storage. Emphasis was given to the differential re sponsiveness of fruits to cold treatment as a function of stage of maturity at harvest. Fruits were held at 1 or 20 °C for 30 days, respectively, or exposed to 1 °C for 10 days and then storaged at 20 °C for up to 30 days. Fruits at 20 °C showed typical climacteric behavior. Differences at 1 °C between maturity stages in ethylene production and ACC oxidase activity were abolished, which showed that cold treatment is an important inducer of climacteric rise in preclimacteric Granny Smith apples. At 1 °C, ethylene production was lower than at 20 °C and the maxima in production were similar for all the stages of maturity, but took place at different times which corresponded exactly to the initial differ ences in harvest dates. After the transfer to 20 °C, fruits exhibited similar behavior as regards ethyl ene production, ACC oxidase activity, and ACC and MACC levels in relation to a harmonization process which is discussed in this study.

scholarly journals Impact of a Brief Postharvest Hot Water Drench Treatment on Decay, Fruit Appearance, and Microbe Populations of California Lemons and Oranges

2003 ◽  
Vol 13 (2) ◽  
pp. 333-338 ◽  
Author(s):  
Joseph L. Smilanick ◽  
David Sorenson ◽  
Monir Mansour ◽  
Jonah Aieyabei ◽  
Pilar Plaza
Keyword(s):  
Sodium Carbonate ◽  
High Volume ◽  
Hot Water ◽  
In Vitro Tests ◽  
Citrus Limon ◽  
Sour Rot ◽  
Green Mold ◽  
Water Treatments ◽  
The Impact

A brief (15 or 30 seconds) high-volume, low-pressure, hot-water drench at 68, 120, 130, 140, or 145 °F (20.0, 48.9, 54.4, 60.0, or 62.8 °C) was applied over rotating brushes to `Eureka' lemons (Citrus limon) and `Valencia' oranges (Citrus sinensis). The impact of this treatment on populations of surface microbes, injury to the fruit, the incidence of green mold (Penicillium digitatum)or sour rot (Geotrichum citri-aurantii), when inoculated into wounds one day prior to treatment, and temperatures required to kill the spores of these fungi and P. italicum suspended in hot water were determined. Fruit microbial populations were determined immediately after treatment. Decay and injuries were assessed after storage for 3 weeks at 55 °F (12.8 °C). The efficacy of the hot water treatments was compared to immersion of fruit in 3% wt/vol sodium carbonate at 95 °F (35.0 °C) for 30 seconds, a common commercial practice in California. Initial yeast and mold populations, initially log10 6.0 per fruit, were reduced to log10 3.3 on lemons and log10 4.2 on oranges by a 15-second treatment at 145 °F. Green mold control improved with increasing temperature and treatment duration. Green mold incidence was reduced from 97.9% and 98.0% on untreated lemons and oranges, respectively, to 14.5% and 9.4% by 30 seconds treatment with 145 °F water. However, immersion of lemons or oranges in 3% wt/vol sodium carbonate was superior and reduced green mold to 8.0% and 8.9%, respectively. Sour rot incidence on lemons averaged 84.3% after all water treatments, and was not significantly reduced, although arthrospores of G. citriaurantii died at lower water temperatures than spores of P. digitatum and P. italicum in in vitro tests. Sodium carbonate treatment for 30 seconds at 95 °F reduced sour rot to 36.7%. None of the treatments caused visible injuries to the fruit.

scholarly journals Postharvest Behavior of Transgenic Cantaloupe Melons with Suppressed ACC Oxidase Activity

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 571d-571
Author(s):  
Jean-Claude Pech
Keyword(s):  
Cell Wall ◽  
Ethylene Production ◽  
Biochemical Composition ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Cell Wall Degradation ◽  
Antisense Gene ◽  
Ripening Process ◽  
Respiratory Behavior ◽  
Exogenous Ethylene

We have generated transgenic Cantaloupe Charentais melons expressing an ACC oxidase antisense gene in which ethylene production was reduced to less than 1% as compared to control untransformed fruits. As a consequence, some aspects of the ripening process were strongly inhibited (aroma volatiles production, chlorophyll and cell wall degradation, pigmentation of the rind, activation of peduncular abscission zone) while others remained unchanged (coloration of the flesh), allowing us to distinguish between ethylene-dependent and ethylene-independent pathways. Some postharvest characteristics of the transgenic fruit are described in terms of expression of ripening-related genes, respiratory behavior, and biochemical composition. Data also are presented showing that exogenous ethylene treatments could reverse the antisense phenotype.

Regulation of ethylene and polyamine synthesis by elevated carbon dioxide in cherimoya fruit stored at ripening and chilling temperatures

1999 ◽  
Vol 26 (3) ◽  
pp. 201 ◽  
Author(s):  
M. T. Muñoz ◽  
P. Aguado ◽  
N. Ortega ◽  
M. I. Escribano ◽  
C. Merodio
Keyword(s):  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Arginine Decarboxylase ◽  
Chilling Temperature ◽  
Polyamine Biosynthesis ◽  
Polyamine Synthesis ◽  
High Co2 ◽  
Chilling Temperatures ◽  
Co2 Level

In this study we focused on the effect of high CO2 level (20%) on ethylene and polyamine biosynthesis in cherimoya (Annona cherimola Mill.) fruits stored at ripening (20˚C) and chilling (6˚C) temperatures. At ripening temperature, CO2 inhibited ethylene production, but 1-aminocyclopropane-1- carboxylate (ACC) oxidase activity was similar to that in ripe control fruits. CO2 treatment led to a decline in putrescine (Put) and a major accumulation of spermidine (Spd) and spermine (Spm) without any effect on arginine decarboxylase (ADC) activity. These results confirm the preferential transformation of Put to Spd and Spm in CO2 -treated fruits. At chilling temperature, the increase in ACC oxidase activity was inhibited and the Vmax of ADC increased. A combination of chilling temperature storage and high CO2 level led to suppression of basal ethylene production while ACC oxidase activity remained unchanged. In addition, fruits held at these conditions had higher polyamine titres than the untreated control. We propose that, in CO2 -treated fruits, the absence of autocatalytic or basal ethylene production, depending on the temperature, may be due to deviation of the S-adenosylmethionine (SAM) pool towards polyamine synthesis, primarily Spd and Spm.

scholarly journals Heat Treatments Delay and Reduce the Ethylene Climacteric in Carnation Flowers (Dianthus caryophyllus L. cv. `White Sim')

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 460B-460
Author(s):  
Sven Verlinden ◽  
William R. Woodson
Keyword(s):  
Heat Treatment ◽  
Ethylene Production ◽  
Dianthus Caryophyllus ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Heat Treatments ◽  
Horticultural Crops ◽  
Beneficial Effects ◽  
Heat Treated ◽  
And Control

High-temperature treatments can be used for disinfestation of a variety of horticultural crops. Carnation flowers were subjected to a heat treatment in order to determine if it is a viable option for disinfestation of this crop. Flowers were exposed to 45°C for 24 hr in the dark, while control flowers were held at RT for 24 hr in the dark. Subsequently, the flowers were held at RT in the light and monitored for ethylene production, an indicator of imminent floral senescence. In the heat-treated flowers, the ethylene climacteric occurred at 96 hr after the heat treatment, a delay of 12 hr when compared to the control. Peak ethylene production was decreased by 25% to 30% in heat-treated flowers. Northern blot analysis of the ethylene biosynthetic pathway genes, ACC synthase, and ACC oxidase, showed that the expression of these genes is delayed by 8 to 16 hr in heat-treated flowers. This indicates that the delay and decrease in ethylene production is at least, in part, due to a delay or reduction in the expression of these genes. Further investigation revealed a decreased responsiveness of the petals to ethylene. Petals from heat-treated and control flowers were exposed to 1 ppm ethylene for 0, 0.5, 1, 2, 4, 6, 12, and 32 hr. The heat-treated petals again showed a delay and a decrease in maximum ethylene production after exposure to ethylene. A delay in expression of ACC synthase and ACC oxidase was also observed. The beneficial effects of exposing carnation flowers to high temperatures, a delay in ethylene production, and reduced responsiveness to ethylene, suggest that heat treatments could be used for disinfestation of this crop.

scholarly journals Reduction of Chilling Injury in Stored `Hass' Avocado Fruit by 38 °C Water Treatments

HortScience ◽  
1997 ◽  
Vol 32 (7) ◽  
pp. 1247-1251 ◽  
Author(s):  
Allan B. Woolf
Keyword(s):  
Electrolyte Leakage ◽  
Chilling Injury ◽  
Persea Americana ◽  
Hot Water ◽  
Skin Tissue ◽  
Heat Treated ◽  
Avocado Fruit ◽  
Temperature Damage ◽  
Hass Avocado ◽  
Water Treatments

`Hass' avocado (Persea americana Mill.) fruit were heat treated in water at 38 °C for 0 to 120 minutes, and stored at 0.5 °C for up to 28 days. After storage, fruit were ripened at 20 °C and their quality evaluated. External chilling injury (CI) developed during storage in nonheated fruit. Skin (exocarp) sectioning showed that browning developed from the base of the exocarp, and with longer storage, this browning moved outwards toward the epidermis. Longer durations of hot water treatment (HWT) progressively reduced CI; 60 minutes was the optimal duration that eliminated external CI, while best maintaining fruit quality. Concomitantly, electrolyte leakage of heated skin tissue increased ≈70% during storage, whereas electrolyte leakage of nonheated skin tissue increased ≈480% over the same period. Thus, significant protection was conferred by HWTs against low temperature damage to avocados and these effects are reflected in the morphology and physiology of the skin tissue.

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