In Silico Study of Ethylene Biosynthesis: Seeking New Effectors of ACC Synthase and ACC Oxidase

2016 ◽  
Vol 11 (3) ◽  
pp. 346-356
Author(s):  
Nada Ayadi ◽  
Sarra Aloui ◽  
Rabeb Shaiek ◽  
Oussama Rokbani ◽  
Faten Raboud ◽  
...  
Keyword(s):  
In Silico ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
In Silico Study

scholarly journals Delaying Broccoli Floret Yellowing by Phytosulfokine α Application During Cold Storage

2021 ◽  
Vol 8 ◽  
Author(s):  
Morteza Soleimani Aghdam ◽  
Majid Alikhani-Koupaei ◽  
Raheleh Khademian
Keyword(s):  
Gene Expression ◽  
Hydrogen Sulfide ◽  
Nutritional Value ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Pheophorbide A ◽  
Postharvest Life ◽  
Cysteine Desulfhydrase ◽  
Pheophorbide A Oxygenase

During postharvest life, broccoli suffers from floret yellowing confining its economic and nutritional value. The objective of the present study was to explore the mechanisms employed by phytosulfokine α (PSKα) at 150 nM for delaying floret yellowing in broccoli during storage at 4°C for 28 days. Our results showed that the higher endogenous accumulation of hydrogen sulfide (H2S) resulting from the higher gene expression and activities of l-cysteine desulfhydrase (LCD) and d-cysteine desulfhydrase (DCD) in broccoli floret treated with 150 nM PSKα may serve as an endogenous signaling molecule for delaying senescence. Moreover, the suppressed ethylene biosynthesis in broccoli floret treated with 150 nM PSKα might be ascribed to lower gene expression and activities of ACC synthase (ACS) and ACC oxidase (ACO). Furthermore, lower gene expression and activities of Mg2+ dechelatase (MDC), pheophytinase (PPH), and pheophorbide a oxygenase (PaO) might be the reasons for the higher accumulation of chlorophyll in broccoli floret treated with 150 nM PSKα. Based on our findings, exogenous PSKα application could be employed as signaling bioactive hormone for retarding floret yellowing of broccoli during storage at 4°C for 28 days.

scholarly journals Reduced ethylene synthesis of mangoes under high CO2 atmosphere storage

2021 ◽  
Vol 43 ◽  
pp. e51540
Author(s):  
Renar João Bender ◽  
Jeffrey Karl Brecht ◽  
Steven Alonzo Sargent
Keyword(s):  
Mangifera Indica ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Ethylene Synthesis ◽  
High Co2 ◽  
Fruit Species ◽  
Co2 Concentrations ◽  
Atmosphere Storage ◽  
Co2 Atmosphere

. High CO2 atmospheres have been reported to be accountable for slower ripening processes of many fruit species. In modified or controlled atmosphere storage of mangoes (Mangifera indica L.) delayed ripening is attributed to the effects of CO2 on ethylene biosynthesis, which is reduced under CO2 concentrations beyond 10%. In the present work the objective was to determine if those elevated CO2 atmospheres on ethylene synthesis could be attributed to the action of CO2 upon ACC oxidase. Mature green or tree ripe `Tommy Atkins` mangoes were, in four experiments, held in a flow through system of either 10 or 25% CO2 mixed to 5% O2 or only air for 14 or 21 days at 5, 8 or 12°C. Mangoes in the 25% CO2 atmosphere did not produce detectable levels of ethylene, whereas under 10% CO2 the production rates were significantly suppressed at 5 or 8°C. However, 1-aminocyclopropane-1-carboxylic acid (ACC) concentrations in mango mesocarp tissue at retrieval from storage were similar to the air controls and ACC synthase activity was not completely inhibited. The direct effects of CO2 concentrations on ACC oxidase activity is to be considered the most important factor in inhibiting ethylene biosynthesis of mangoes under 25% CO2 atmospheres.

scholarly journals Low Oxygen and Elevated Carbon Dioxide Atmospheres Inhibit Ethylene Biosynthesis in Preclimacteric and Climacteric Apple Fruit

1997 ◽  
Vol 122 (4) ◽  
pp. 542-546 ◽  
Author(s):  
James R. Gorny ◽  
Adel A. Kader
Keyword(s):  
Enzyme Activity ◽  
Mrna Level ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Transcript Abundance ◽  
Ethylene Biosynthesis ◽  
Apple Fruit ◽  
Low Oxygen ◽  
Rate Limiting Step

Autocatalytic C2H4 biosynthesis in preclimacteric apple fruit (Malus domestica Borkh. `Golden Delicious') was prevented by storage in atmospheres of 20% CO2-enriched air (17% O2 + 63% N2) or 0.25% O2 (balance N2). In preclimacteric fruit, both treatments inhibited C2H2 biosynthesis by suppressing expression of ACC synthase (ACC-S) at the mRNA level. ACC oxidase (ACC-O) mRNA abundance and in vitro enzyme activity also were impaired by these treatments. However, the conversion of ACC to C2H4 never became the rate limiting step in C2H4 biosynthesis. C2H4 biosynthesis also was effectively inhibited in climacteric apple fruit kept in air + 20% CO2 or 0.25% O2. Climacteric apples also exhibited suppressed expression of ACC-S at the mRNA level, while ACC-O transcript abundance, enzyme activity, and protein abundance were reduced only slightly. ACC-S is the key regulatory enzyme of C2H4 biosynthesis and is the major site at which elevated CO2 and reduced O2 atmospheres inhibit C2H4 biosynthesis, irrespective of fruit physiological maturity. Chemical names used: 1-aminocyclopropane-1-carboxcylic acid (ACC).

scholarly journals Elevated CO2 and/or Low O2 Atmospheres Influence ACC Synthase and ACC Oxidase during Long-term Storage of `Golden Delicious' Apple Fruit

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 782C-782
Author(s):  
James R. Gorny ◽  
Adel A. Kader
Keyword(s):  
Blot Analysis ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Apple Fruit ◽  
Long Term Storage ◽  
Golden Delicious ◽  
Compare And Contrast

The objective of this study was to compare and contrast the mode of action by which elevated carbon dioxide and/or reduced oxygen atmospheres inhibit ethylene biosynthesis. `Golden Delicious' apple fruit were placed at 0C in one of the following four atmospheres: 1) air; 2) air + 5% CO2; 3) 2% O2 + 98% N2; or 4) 2% O2 + 5% CO2 + 93% N2 and then sampled monthly for 4 months. Ethylene biosynthesis rates and in vitro ACC synthase activities were closely correlated in all treatments. In vitro ACC synthase activity and ethylene biosynthesis rates were lowest in fruit treated with 5% CO2 + 2% O2, while air-treated fruit had the highest ethylene biosynthesis rate and in vitro ACC synthase activity. Fruit treated with air + 5% CO2, or 2% O2 + 98% N2, had intermediate ethylene and in vitro ACC synthase activities. In vitro ACC oxidase was significantly different among treatments, but not as closely correlated with the ethylene biosynthesis rate as in vitro ACC synthase activity. Western blot analysis of the ACC oxidase protein was performed to determine if activity differences among treatments were correlated with the amount of enzyme present in vivo. ACC synthase and ACC oxidase mRNA transcript of abundance was determined via Northern blot analysis. Results will be discussed regarding how ethylene biosynthesis is inhibited at the molecular level by elevated CO2 and/or reduced O2.

scholarly journals Ethylene Biosynthesis Inhibition Combined with Cyanide Degradation Confer Resistance to Quinclorac in Echinochloa crus-galli var. mitis

2020 ◽  
Vol 21 (5) ◽  
pp. 1573 ◽  
Author(s):  
Muhammad Zia Ul Haq ◽  
Zheng Zhang ◽  
Jiajia Wei ◽  
Sheng Qiang
Keyword(s):  
Binding Free Energy ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Resistance Level ◽  
Relative Expression ◽  
Positive Correlation ◽  
Ethylene Response ◽  
Cyanide Degradation ◽  
Oxidase Enzyme

Echinochloa crus-galli var. mitis has rarely been reported for herbicide resistance, and no case of quinclorac resistance has been reported so far. Synthetic auxin-type herbicide quinclorac is used extensively to control rice weeds worldwide. A long history of using quinclorac in Chinese rice fields escalated the resistance in E. crus-galli var. mitis against this herbicide. Bioassays in Petri plates and pots exhibited four biotypes that evolved into resistance to quinclorac ranking as JS01-R > AH01-R > JS02-R > JX01-R from three provinces of China. Ethylene production in these biotypes was negatively correlated with resistance level and positively correlated with growth inhibition. Determination of the related ethylene response pathway exhibited resistance in biotypes that recorded a decline in 1-aminocyclopropane-1-carboxylic acid (ACC) content, ACC synthase oxidase activities, and less inducible ACS and ACO genes expressions than the susceptible biotype, suggesting that there was a positive correlation between quinclorac resistance and ethylene biosynthesis inhibition. Cyanides produced during the ethylene biosynthesis pathway mainly degraded by the activity of β-cyanoalanine synthase (β-CAS). Resistant biotypes exhibited higher β-CAS activity than the susceptible ones. Nucleotide changes were found in the EcCAS gene of resistant biotypes as compared to sensitive ones that caused three amino acid substitutions (Asn-105-Lys, Gln-195-Glu, and Gly-298-Val), resulting in alteration of enzyme structure, increased binding residues in the active site with its cofactor, and decreased binding free energy; hence, its activity was higher in resistant biotypes. Moreover, these mutations increased the structural stability of the enzyme. In view of the positive correlation between ethylene biosynthesis inhibition and cyanide degradation with resistance level, it is concluded that the alteration in ethylene response pathway or at least variation in ACC synthase and ACC oxidase enzyme activities—due to less relative expression of ACS and ACO genes and enhanced β-CAS activity, as well as mutation and increased relative expression of EcCAS gene—can be considered as a probable mechanism of quinclorac resistance in E. crus-galli var. mitis.

scholarly journals Identifying Flavor Metabolites Under Ethylene Regulation in Apples

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 781B-781
Author(s):  
Bruno Defilippi* ◽  
Abhaya Dandekar ◽  
Adel Kader
Keyword(s):  
Headspace Analysis ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Complex Trait ◽  
Ethylene Biosynthesis ◽  
Aroma Production ◽  
Ethylene Action ◽  
Ethylene Regulation ◽  
Malic Acid Degradation ◽  
Apple Fruits

To understand the role of ethylene in overall flavor of apple fruits, ethylene production, and action were reduced using apple trees lines transformed for suppressing activity of ACC-synthase or ACC-oxidase enzymes, and 1-methylcyclopropene (1-MCP), an ethylene action inhibitor. A major reduction in ethylene biosynthesis and respiration rates was measured in fruits from these treatments. As expected, we found differential levels of dependence of flavor components on ethylene biosynthesis and action. Regarding aroma production, an ethyleneassociated event, headspace analysis showed a reduction in ester production in the ethylene-suppressed lines and in the apples treated with 1.0 μL·L-1 1-MCP for 20 hours at 20 °C. However, no major differences were observed in concentrations of alcohol and aldehyde volatiles. Other flavor metabolites that showed an ethylene-dependent pattern were organic acids and sugars. Malic acid degradation was significantly reduced under ethylene suppressed conditions, showing a recovery after exposing the fruit to ethylene. Sucrose and fructose concentrations were influenced by suppression or enhancement of ethylene. Total phenolics and individual phenolics showed an ethylene-dependent behavior only when ethylene biosynthesis was reduced, but not when ethylene action was affected. These results suggest that the regulatory mechanisms of aroma biosynthesis in apple are under partial ethylene regulation. Therefore, we are using the ethylene suppressed apple fruits study the channeling and regulation of other metabolic pathways that lead to the manifestation of a complex trait like fruit quality.

Effects of Exogenous Ethylene on AC and Rin Tomato Fruit

2014 ◽  
Vol 1033-1034 ◽  
pp. 677-680
Author(s):  
Ling Li ◽  
Hai Xue Liu ◽  
Yong Bo Peng ◽  
Shi Li ◽  
Tie Ling Liu
Keyword(s):  
Respiration Rate ◽  
Ethylene Production ◽  
Tomato Fruit ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Flesh Firmness ◽  
Ethephon Treatment ◽  
Production Increase ◽  
Exogenous Ethylene

The flesh firmness of AC andrinmutant tomato fruits picked freshly were the largest. Respiration rate and ethylene production were very low at this time. With ethylene production increase, fruit firmness began to decline. 100μL/L ethephon significantly increased AC tomato fruit ethylene release, respiration rate, ACS activity and ACO activity, and decreased flesh firmness. However, there were no significant differences inrinmutant between control and ethephon treatment. It was shown RIN transcription factor regulated ethylene biosynthesis by ACC synthase and ACC oxidase.

scholarly journals Is Ethylene the Ripening Hormone

2020 ◽  
pp. 1-7
Author(s):  
Senewa Bobby Pholoma
Keyword(s):  
Fruit Ripening ◽  
Wide Spectrum ◽  
Cell Metabolism ◽  
Economic Value ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Vital Role ◽  
Limiting Factors ◽  
Physiological Processes

The fruits constitute a commercially important and nutritionally indispensable food commodity since they play a vital role in human nutrition by supplying the necessary growth factors essential for maintaining normal health.  One of the limiting factors that influence their economic value is the relatively short ripening period and reduced post-harvest life.  The fruit ripening involves a wide spectrum of coordinated biochemical and physiological processes that eventually leads to development of soft edible fruit with desirable qualities such as carotenoids, anthocyanin, color, sweetness, texture, firmness, flavor and aroma.  The ripening is the phase of fruit development just before senescence, therefore the excessive tissues softening due to the high ethylene exposure leads to the spoilage upon the storage.  Ethylene, a fruit ripening hormone can trigger many events of cell metabolism including ripening particularly in climacteric fruits even in minute amounts.  As fruit mature, the rate of ACC and ethylene biosynthesis increases as well as the enzyme activities for ACC oxidase and ACC synthase enhance.  However, the application of ethylene inhibitors such as 1-MCP, AVG and the ethylene remover proved to reduce the ripening where some quality attributes of ripening were reduced due to suppressed expression of the ripening hormone.

scholarly journals Changes in Abscisic Acid Levels, Ethylene Biosynthesis, and Protein Patterns during Fruit Maturation of `Granny Smith' Apples

2000 ◽  
Vol 125 (2) ◽  
pp. 183-189 ◽  
Author(s):  
I. Lara ◽  
M. Vendrell
Keyword(s):  
Abscisic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Protein Accumulation ◽  
Protein Patterns ◽  
Pulp Tissue ◽  
Endogenous Aba

Endogenous ABA, free and conjugated ACC concentrations, ethylene-forming capacity (EFC), and presence of ACC oxidase (ACO) and ACC synthase (ACS) proteins were monitored during the preharvest maturation period of `Granny Smith' apple fruit (Malus sylvestris L. Mill. var. domestica (Borkh.) Mansf. `Granny Smith'). Total proteins from peel and pulp tissues were also extracted at different maturity stages and separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis, providing evidence of differential protein accumulation during fruit development. Endogenous ABA concentration in the peel tissue was higher than in pulp, the highest level occurring ≈2 months before commercial harvest. In the pulp tissue, concomitant increases in ACC and ABA concentrations were observed, preceded by a peak in EFC. However, no ACO or ripening-related ACS proteins were detectable throughout the period considered, suggesting that very low levels of both enzymes are present during the preclimacteric stage of `Granny Smith' apples. A hypothesis on the possible interaction between ABA and ethylene during maturation of `Granny Smith' apples is proposed. Chemical names used: abscisic acid (ABA); 1-aminocyclopropane-1-carboxylic acid (ACC).

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