MOLECULAR BIOLOGICAL INVESTIGATIONS OF ACC OXIDASE AND ITS EXPRESSION ATTENDING APPLE FRUIT RIPENING

We have studied the effects of MCP and low O2, applied singly and in combination, on apple fruit ripening at 1, 7, and 18 °C. The single application of 2 ppm MCP is more effective in delaying the onset of the C2H4 climacteric than is 1% O2. However, the combined application has a much larger effect than the single applications of either MCP or 1% O2. For instance, at 7 °C, the onset of the C2H4 climacteric occurs at 15, 50, and 90–95 days for the controls, 1% O2 and 2 ppm MCP, respectively, whereas the combined application of 2 ppm MCP and 1% O2 suppressed the initiation of the C2H4 climacteric for 200 days, the duration of the experiment. The retardation of the climacteric onset by the treatments is associated with the suppression of ACC-synthase (ACS1) and the putative receptor ERS1. The accumulation of their transcripts is critically dependent on the rate of C2H4 evolution. As expected, the combined application of MCP and 1% O2 completely suppressed the expression of both genes. Yet when the fruits were transferred to 18 °C in air, they ripened normally. A similar pattern of inhibition in response to the above treatments was also observed with a C2H4-dependent MAPK. The expression of ETR1, ETR2 and ACC-oxidase was not affected by the treatments. The nature of this strong effect of the combined application of MCP and low O2 is not clear. It should be pointed out that MCP does not inhibit the induction of hypoxic proteins such as ADH.

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INCREASE IN ESTERASE AS A FUNCTION OF APPLE FRUIT RIPENING MALUS PUMILA

Acta Horticulturae ◽

10.17660/actahortic.1983.138.9 ◽

1983 ◽

pp. 83-92 ◽

Cited By ~ 3

Author(s):

P.W. Goodenough

Keyword(s):

Fruit Ripening ◽

Apple Fruit ◽

Malus Pumila

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Non-involvement of ACC and ACC oxidase activity in pepper fruit ripening

Postharvest Biology and Technology ◽

10.1016/0925-5214(94)00025-n ◽

1995 ◽

Vol 5 (4) ◽

pp. 295-302 ◽

Cited By ~ 24

Author(s):

M.T Pretel ◽

M Serrano ◽

A Amoros ◽

F Riquelme ◽

F Romojaro

Keyword(s):

Fruit Ripening ◽

Oxidase Activity ◽

Acc Oxidase ◽

Pepper Fruit

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Intermittent Warming Effects on Superficial Scald of Apple Fruit

HortScience ◽

10.21273/hortsci.31.4.605b ◽

1996 ◽

Vol 31 (4) ◽

pp. 605b-605

Author(s):

Thair F. Alwan ◽

Christopher B. Watkins

Keyword(s):

Fruit Ripening ◽

Marked Reduction ◽

Apple Fruit ◽

Oxidation Products ◽

Superficial Scald ◽

Cooperative Agreement ◽

Postharvest Treatments ◽

Conjugated Trienes ◽

Hexane Extracts ◽

Intermittent Warming

Fruit of `Cortland', `Delicious' and `Law Rome' were warmed for 24 hours at 20°C either weekly, once every 2 weeks, or once every 3 weeks during storage. The effect of these treatments on fruit ripening and concentrations of alpha-farnesene and conjugated trienes in hexane extracts of the skin were measured during storage. Without warming, scald incidence of the cultivars was 70%, 14%, and 85%, respectively. Intermittent warming treatments resulted in a marked reduction of scald though effectiveness was affected by cultivar. In `Cortland', scald was reduced only by the weekly warming treatment (10%) as was less effective than DPA (1%). In `Delicious', all warming treatments were equally effective. In `Law Rome', weekly warming resulted in better control of scald (3%) than DPA (14%) and less frequent warming was proportionately less effective in controlling the disorder. Concentrations of conjugated trienes at 281 nm did not relate consistently to scald incidence after storage. However, ratios of conjugated trienes of 258 nm or 269 nm with 281 nm strongly support a hypothesis that non-toxic and toxic oxidation products of alpha-farnesene interact and influence the effectiveness of postharvest treatments on scald control (Du and Bramlage, 1993; JASHS 118:807-813). A hypothesis relating the interactions between ripening and scald development will be presented. Supported in part by USDA Specific Cooperative Agreement 58-1931-5-017.

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Effect of 1-MCP on Apple Fruit Ripening and Volatile Production

HortScience ◽

10.21273/hortsci.32.3.536d ◽

1997 ◽

Vol 32 (3) ◽

pp. 536D-536 ◽

Cited By ~ 8

Author(s):

J. Song ◽

M.S. Tian ◽

D.R. Dilley ◽

R.M. Beaudry

Keyword(s):

Fruit Ripening ◽

Ethylene Production ◽

Quality Criterion ◽

Apple Fruit ◽

Climacteric Fruit ◽

Aroma Production ◽

Ethylene Action ◽

Important Quality ◽

The Relationship ◽

Volatile Production

Aroma production by apple fruit is an important quality criterion and has been found to be a fruit-ripening-related process. 1-Methylcyclopropene (1-MCP), an effective ethylene action inhibitor, was used to study the relationship between volatile biosynthesis, ethylene action, and fruit ripening in `Golden Delicious' apple fruit. Pre-climacteric fruit were treated with 1-MCP vapors at a concentration of 500 parts per billion (v/v) at 23°C. 1-MCP prevented the climacteric rise of ethylene production, respiration, and volatile production, while untreated fruits developed typical climacteric changes in ethylene production, respiration and volatile production. Applying ethylene at 15–20 parts per million for 24 hr 11 days after 1-MCP treatment could not overcome the effect of 1-MCP, suggesting that 1-MCP inhibited ethylene action irreversibly. Interestingly, when 1-MCP-treated tissue were fed butanol and butyric acid, they converted these compounds to their corresponding esters butylacetate and butylbutanoate. Thus precursor supply is apparently limiting and appears to be ethylene-dependent.

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Brassinosteroids Suppress Ethylene Biosynthesis via Transcription Factor BZR1 in Pear and Apple Fruit

10.1101/2020.02.27.968800 ◽

2020 ◽

Author(s):

Yinglin Ji ◽

Yi Qu ◽

Zhongyu Jiang ◽

Xin Su ◽

Pengtao Yue ◽

...

Keyword(s):

Transcription Factor ◽

Fruit Ripening ◽

Ethylene Production ◽

Plant Hormone ◽

Expression Profiles ◽

Acc Synthase ◽

Ethylene Biosynthesis ◽

Apple Fruit ◽

Pear Fruit ◽

Climacteric Fruit

ABSTRACTThe plant hormone ethylene is important for the ripening of climacteric fruit, such as pear (Pyrus ussuriensis), and the brassinosteroid (BR) class of phytohormones affects ethylene biosynthesis during ripening, although via an unknown molecular mechanism. Here, we observed that exogenous BR treatment suppressed ethylene production during pear fruit ripening, and that the expression of the transcription factor PuBZR1 was enhanced by epibrassinolide (EBR) treatment during pear fruit ripening. PuBZR1 was shown to interact with PuACO1, which converts 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene, and suppress its activity. We also observed that BR-activated PuBZR1 bound to the promoters of PuACO1 and of PuACS1a, which encodes ACC synthase, and directly suppressed their transcription. Moreover, PuBZR1 suppressed the expression of transcription factor PuERF2 by binding its promoter, and PuERF2 bound to the promoters of PuACO1 and PuACS1a. We concluded that PuBZR1 indirectly suppresses the transcription of PuACO1 and PuACS1a through its regulation of PuERF2. Ethylene production and the expression profiles of the corresponding apple (Malus domestica) homologs showed similar changes following EBR treatment. Together, these results suggest that BR-activated BZR1 suppresses ACO1 activity and the expression of ACO1 and ACS1a, thereby reducing ethylene production during pear and apple fruit ripening. This likely represents a conserved mechanism by which exogenous BR suppresses ethylene biosynthesis during climacteric fruit ripening.One-sentence summaryBR-activated BZR1 suppresses ACO1 activity and expression of ACO1 and ACS1a, which encode two ethylene biosynthesis enzymes, thereby reducing ethylene production during pear and apple fruit ripening.

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Using Chloroplast Fluorescence for Prediction of Scald Development in `Red Delicious' Apple Fruit

HortScience ◽

10.21273/hortsci.30.4.816b ◽

1995 ◽

Vol 30 (4) ◽

pp. 816B-816 ◽

Cited By ~ 3

Author(s):

Randolph M. Beaudry ◽

Jun Song ◽

Weimin Deng

Keyword(s):

Quantum Yield ◽

Ambient Temperature ◽

Fruit Ripening ◽

Chilling Injury ◽

Apple Fruit ◽

Significant Decline ◽

Yield Response ◽

Fruit Firmness ◽

Symptom Development ◽

Predictive Tool

Apple scald (peel browning) is hypothesized to involve a chilling disorder. Numerous studies have linked chloroplast fluorescence changes with chilling injury before symptom development. Therefore, chloroplast fluorescence was used for the prediction of scald in apples. `Red Delicious' apple fruit were harvested at three maturities and stored at 1 to 2C. They were removed from storage weekly and placed at ambient temperature (22C). Chloroplast fluorescence was measured at 0, 3, and 7 days after removal. A significant decline in quantum yield response (Fv/Fm), which indicates a reduction of chloroplast function, was recorded after 30 days in first-harvest fruit and 40 to 50 days in the second- and third-harvest fruit. The decline in Fv/Fm preceded scald development by ≈30 days in first-harvest fruit and 20 to 30 days in second- and third-harvest fruit. The data suggest that fluorescence changes and scald development may be related physiologically. Fruit firmness and other fruit ripening phenomena were also measured and their relationship to the fluorescence and scald development were investigated. The results indicated that the chloroplast fluorescence may be used as a predictive tool for scald development in stored apple fruit.

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