scholarly journals The effects of ACS (1-aminocyclopropane-l-carboxylate synthase) gene down regulation on ethylene production and fruit softening in transgenic apple

Author(s):  
Zs. Galli ◽  
E. Kiss ◽  
G. Hrazdina ◽  
L. Heszky

A detailed examination of the production of ethylene and other ripening parameters during storage period has been undertaken in transgenic apple fruits, where the ethylene biosynthesis was inhibited by antisense ACS (l-aminocyclopropane-l-carboxylate synthase) gene. Data indicate down regulation of ethylene production, softening and spoilage in some transgenic lines. In some cases ethylene production was inhibited for over 90 percent, considerable reduction of softening and spoilage was observed probably due to the reduced activity of cell wall degradable enzymes. ACS activity was also monitored during ripening. The fruits of the best transgenic lines could be stored for minimum 4-5 months longer under 5 °C cold room storage conditions and one month longer at normal room temperature. This molecular approach can provide an alternative way to replace the commonly used and costly atmospheric storage of fruits.

2005 ◽  
Vol 32 (10) ◽  
pp. 891 ◽  
Author(s):  
Nigel E. Gapper ◽  
Simon A. Coupe ◽  
Marian J. McKenzie ◽  
Richard W. Scott ◽  
Mary C. Christey ◽  
...  

To gain an in-depth understanding of the role of ethylene in post harvest senescence, we used broccoli (Brassica oleracea var. italica) as our model species. The senescence-associated asparagine synthetase (AS) promoter from asparagus was used to drive the expression of an antisense 1-aminocyclopropane-1-carboxylate oxidase (ACO) cDNA from broccoli, BoACO2, to reduce ethylene production following harvest. Physiological analyses revealed that transgenic broccoli lines harbouring the antisense BoACO2 gene construct (designated as AS-asACO) displayed delayed senescence in both detached leaves and detached heads as measured by hue angle. Harvested floret tissue from these plants also showed a delayed loss of chlorophyll, lower protease activity and higher total protein content, and changes in transcript levels of senescence marker genes when compared with wild type and transgenic lines transformed with an empty T-DNA. Genes that were down-regulated included those coding for cysteine protease (BoCP5), metallothionein-like protein (BoMT1), hexokinase (BoHK1), invertase (BoINV1) and sucrose transporters (BoSUC1 and BoSUC2). Northern analysis for BoACO1 and BoACO2, ACO assays and western analysis, revealed reduced ACO transcript, enzyme activity and protein accumulation, as well as reduced ethylene production in the transgenic AS-asACO lines when compared with controls, confirming that a key enzyme regulating ethylene biosynthesis was reduced in these plants. This, together with the changes observed in gene expression, confirm a significant role for ethylene in regulating the events leading to senescence in broccoli following harvest.


2008 ◽  
Vol 14 (3) ◽  
pp. 285-294 ◽  
Author(s):  
J. Graell ◽  
M.L. Lopez ◽  
T. Fuentes ◽  
G. Echeverría ◽  
I. Lara

Starch index (SI), color, firmness, titratable acidity (TA), soluble solids content (SSC), ethylene production, and aroma volatile emission were recorded weekly during on-tree maturation of `Mondial Gala' apples. Fruit were harvested on commercial date and held for 3.5 and 6.5 months in regular atmosphere (RA) or in three controlled atmospheres (CA) (2% O2 :2% CO2, 1% O2 : 1 % CO2 and 1% O2 :3% CO2). After each storage period plus 0 and 7 days at 20 °C, color, firmness, TA, SSC, aroma volatile emission, acetaldehyde and ethanol concentrations, and sensory acceptability were evaluated. At orchard, changes in SI, SSC, background color, and aroma volatile emission were almost concomitant or slightly previous to the increase in ethylene production. During storage, all three CA conditions, regardless of storage period, led to better preservation of standard quality. CA-stored fruit also received higher acceptability scores, although aroma volatile emission was decreased in response to these storage conditions. At the end of long storage (plus shelf life period), fruit stored in 1 :1 atmosphere showed a good retention of firmness and TA in comparison to the rest of CA-fruit. Fruit stored under all considered CA conditions showed similar aroma volatile emission after 3.5 or 6.5 months of storage. Storage period had no apparent influence on the aroma volatile emission of CA-stored apples, with the exception of fruit stored in 2:2 atmosphere immediately upon removal from storage. No significant differences in sensory acceptability were found either for fruit stored under different CA conditions during 3.5 months immediately after transfer to 20 °C. In contrast, fruit stored in either 1 : 1 or 2: 2 atmospheres during 6.5 months were better accepted by consumers than those stored in 1 : 3 atmosphere upon removal from cold storage. However, these differences disappeared after 7 days of shelf-life at 20 °C.


2018 ◽  
Vol 115 (21) ◽  
pp. 5606-5611 ◽  
Author(s):  
Qingxin Song ◽  
Atsumi Ando ◽  
Dongqing Xu ◽  
Lei Fang ◽  
Tianzhen Zhang ◽  
...  

Heterosis is widely applied in agriculture; however, the underlying molecular mechanisms for superior performance are not well understood. Ethylene biosynthesis and signaling genes are shown to be down-regulated in Arabidopsis interspecific hybrids. Ethylene is a plant hormone that promotes fruit ripening and maturation but inhibits hypocotyl elongation. Here we report that application of exogenous ethylene could eliminate biomass vigor in Arabidopsis thaliana F1 hybrids, suggesting a negative role of ethylene in heterosis. Ethylene biosynthesis is mediated by the rate-limiting enzyme, 1-aminocyclopropane-1-carboxylate synthase (ACS). Down-regulation of ACS genes led to the decrease of ethylene production, which was associated with the high-vigor F1 hybrids, but not with the low-vigor ones. At the mechanistic level, expression of ACS genes was down-regulated diurnally and indirectly by Circadian Clock Associated 1 (CCA1) during the day and directly by Phyotochrome-Interacting Factor 5 (PIF5) at night. Consistent with the negative role of ethylene in plant growth, biomass vigor was higher in the acs mutants than in wild-type plants, while increasing endogenous ethylene production in the hybridizing parents reduced growth vigor in the hybrids. Thus, integrating circadian rhythms and light signaling into ethylene production is another regulatory module of complex biological networks, leading to biomass heterosis in plants.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 850
Author(s):  
Annalaura Lopez ◽  
Federica Bellagamba ◽  
Erica Tirloni ◽  
Mauro Vasconi ◽  
Simone Stella ◽  
...  

Caviar is a semi-preserved fish preparation in which cold storage (around 0 °C) and packaging under anaerobic conditions are fundamental to guarantee adequate safety parameters. Consumers seem to prefer caviar prepared with food salt only, but according to the needs of the different distribution channels, some preservatives are used in order to prolong its shelf life and to allow less restrictive storage conditions. Traditionally, the most common preservative was sodium tetraborate (borax), a salt that contributes to the sensory profile of caviar. However, due to its toxicity, borax has been banned in many countries, and the current trend is to reduce or eliminate its use. In this study, we evaluated the evolution of food safety parameters (pH, water activity, microbiological parameters) and the volatile profile during 14 months of storage in caviar samples treated with three different preservatives: I. exclusively NaCl, II. a mixture of borax and NaCl, and III. a mixture of organic acids and salts. Microbial presence was studied by means of plate counts; volatile organic compounds were identified on the sample headspace by means of solid phase microextraction with gas-chromatography and mass spectrometry. Results showed relevant differences among the three treatments investigated, with salt samples characterized by the highest viable counts and the greatest presence of volatile products driven by oxidative and spoilage processes, mainly occurring toward lipid and amino acids. On the contrary, the mixture of organic acids and salts showed the best response during the entire storage period. Finally, the employment of a multiparametric statistic model allowed the identification of different clusters based on the time of ripening and the preservative treatments used.


2014 ◽  
Vol 86 (1) ◽  
pp. 485-494 ◽  
Author(s):  
CRISTIANO ANDRÉ STEFFENS ◽  
CASSANDRO V.T. DO AMARANTE ◽  
ERLANI O. ALVES ◽  
AURI BRACKMANN

The objective of this study was to evaluate the effect of controlled atmosphere (CA) on quality preservation of ‘Laetitia’ plums, mainly on internal breakdown, in order to determine the best CA storage conditions. Two experiments were carried out one in 2010, and another in 2011. In 2010, besides cold storage (CS; 21.0 kPa O2 + 0.03 kPa CO2), the fruits were stored under the following CA conditions (kPa O2+kPa CO2): 1+3, 1+5, 2+5, 2+10, and 11+10. In 2011, the fruits were stored under CS and CA of 1+0, 1+1, 2+1, and 2+2. The fruit stored under different CA conditions had lower respiration and ethylene production, better preservation of flesh firmness, texture and titratable acidity, lower skin red color, and lower incidence of skin cracking than the fruit in CS. In 2010, the fruit under CA with 2+5, 1+5, and 1+3 had a pronounced delay in ripening, although it exhibited a high incidence of internal breakdown. In 2011, the CA conditions with 2+1 and 2+2 provided the best delay in ripening and a reduced incidence of internal breakdown. The best CA condition for cold storage (at 0.5°C) of ‘Laetitia’ plums is 2 kPa O2 + 2 kPa CO2.


1990 ◽  
Vol 30 (5) ◽  
pp. 693 ◽  
Author(s):  
ME Edwards ◽  
RM Blennerhassett

Three trials were undertaken to study storage conditions and handling procedures required to maximise the postharvest storage life of honeydew melons (Cucumis melo L. var. inodorus Naud.).Honeydew melons treated with chlorine (1000 mg/L), benomyl (250 mg/L) + guazatine (500 mg/L), shrink wrap (17 ym Cryovac XDR film), Semperfresh, wax, or combinations of these treatments were stored at 4 or 8�C, for 4 or 6 weeks. Benomyl plus guazatine reduced the development of storage rots associated with Alternaria and Fusarium spp. The use of shrink wrap and wax reduced water loss by melons but increased fungal infection in some cases. Shrink wrapping combined with the fungicide treatment effectively reduced the incidence of fungal breakdown in the storage period for up to 4 weeks. Wax coating with full strength Citruseal wax caused anaerobic tissue breakdown. Melons were affected by chilling injury at 4�C. Control of bacterial rots with benomyl + guazatine or with chlorine was variable. Semperfresh did not reduce the incidence of fungal breakdown or water loss from the melons. The results indicate that storage of honeydew melons for 4 weeks at 8�C by pretreating with fungicide is possible but the melons soften and rot after 6 weeks, making them unsaleable. Four weeks should be adequate to allow for sea freighting of honeydew melons to markets in South East Asia. Further research is required to determine the optimum storage temperature for honeydew melons.


2004 ◽  
Vol 22 (4) ◽  
pp. 690-695 ◽  
Author(s):  
Marcos G. Cunha ◽  
David M. Rizzo

A new potato tuber disease has been observed in the Tulelake region, California, USA, since 1995, with tuber symptoms suggestive of silver scurf disease (Helminthosporium solani). In this work we isolated, identified and demonstrated the nature of the causal agent of this potato disease in California. In addition, the distribution of H. solani in potato fields and the inoculum potential at harvest time were investigated. Disease progress and H. solani spore populations were also characterised under commercial storage conditions. The main fungal genera associated with potato tubers in storage were Helminthosporium solani, Colletotrichum sp., Fusarium sp., and Rhizoctonia sp. The results of Koch's postulates indicated that H. solani is responsible for the outbreak of silver scurf in the Tulelake region. In a disease survey in three commercial potato fields naturally infested, H. solani infections occurred in all fields. However, the extension of the infections differed significantly between the fields. During potato storage, silver scurf usually increased over time. The percentage of the tuber surface covered by silver scurf varied from 3.5% up to 35.5% during the storage period. The number of H. solani lesions per tuber also progressively increased from 6% up to 35%, six months after storage. H. solani spore populations also increased over time in all studied potato stores; nevertheless, they followed no consistent pattern, exhibiting multiple and variable peaks of increase and reduction during the period of storage.


2008 ◽  
Vol 133 (6) ◽  
pp. 727-734 ◽  
Author(s):  
Hong Zhu ◽  
Eric P. Beers ◽  
Rongcai Yuan

Effects of naphthaleneacetic acid (NAA) and aminoethoxyvinylglycine (AVG) on young fruit abscission, leaf and fruit ethylene production, and expression of genes related to ethylene biosynthesis and cell wall degradation were examined in ‘Delicious’ apples (Malus ×domestica Borkh.). NAA at 15 mg·L−1 increased fruit abscission and ethylene production of leaves and fruit when applied at the 11-mm stage of fruit development, whereas AVG, an inhibitor of ethylene biosynthesis, at 250 mg·L−1 reduced NAA-induced fruit abscission and ethylene production of leaves and fruit. NAA also increased expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase genes (MdACS5A and MdACS5B), ACC oxidase gene (MdACO1), and ethylene receptor genes (MdETR1a, MdETR1b, MdETR2, MdERS1, and MdERS2) in fruit cortex and fruit abscission zones. However, AVG reduced NAA-induced expression of these genes except for MdERS2 in fruit abscission zones. NAA increased expression of the polygalacturonase gene MdPG2 in fruit abscission zones but not in fruit cortex, whereas AVG reduced NAA-enhanced expression of MdPG2 in fruit abscission zones. The expression of β-1,4-glucanase gene MdCel1 in fruit abscission zones was decreased by NAA but was unaffected by AVG. Our results suggest that ethylene biosynthesis, ethylene perception, and the MdPG2 gene are involved in young fruit abscission caused by NAA.


2021 ◽  
Vol 845 (1) ◽  
pp. 012094
Author(s):  
I M Novikova ◽  
O M Blinnikova ◽  
L G Eliseeva ◽  
D A Blinnikova

Abstract At present, the preservation of the consumer properties of berry products is an urgent problem. Use of fresh garden strawberries is limited by a short storage period and seasonality. Under optimal storage conditions in a normal atmosphere, the average shelf life of strawberries is from 2 to 9 days depending on the variety. To meet the needs of the population in garden strawberries and meet the physiological needs in a unique complex of biologically active substances, strawberries are subjected to different processing methods. Drying being a type of fruit and berry products processing has the following advantages: a significant increase in the shelf life of products, a decrease in the mass and storage volumes of dried berries, preservation of minerals, carbohydrates, dietary fiber, antioxidants, bioflavonoids and many biologically active compounds in berries. Modern drying technologies allow preserving the content of essential vitamins to its full extent. Comparison of two technologies for drying garden strawberries has established that vitamins and other biologically active substances are well preserved in berries. Berries dried by convective vacuum-impulse method (CVI) are recommended to be used for food enrichment.


2017 ◽  
Vol 54 (2) ◽  
pp. 368-374
Author(s):  
Roxana Nicoleta Ratu ◽  
Marius Giorgi Usturoi ◽  
Daniel Simeanu ◽  
Cristina Simeanu ◽  
Alexandru Usturoi ◽  
...  

n the current paper, we aimed to analyze the way in which packing (different polyethylene types) influence the quality of pasteurized melange during storage, packing being realized in units of 1 kg (Tetra Pak) (batch Lexp-1) and units of 5 kg (Bag in box) (batch Lexp-2). Products were stored during a period of 28 days at a temperature of +4�C, qualitative determinations being realized in first day (day 0), at 7 days, at 14 days, 21 days and in day 28 of storage. Were effectuated a sensorial examination and chemical analysis were was established the content in dry matter (%), water (%), proteins (%), content in essential amino acids (isoleucine, methionine, tryptophan, phenylalanine) and non-essential amino acids (alanine, histidine, glycine, serine) (mg/100g) as well as the content in lipids (%) establishing their profile by identification of some saturated fatty acids (16:0 mg/100g and 18:0 mg/100g) and unsaturated fatty acids (16:1 mg/100g and 18:1 mg/100g). After sensorial examinations, the first modifications were observed at the checking effectuated in day 21 for batch Lexp-2, the obtained score being of 18 points, and at checking effectuated in day 28 was given a score of 18 points for melange belonging to batch Lexp-1 and only 14 points for melange from batch Lexp-2. Differences were recorded also in case of chemical composition of products, so for protein content at batch Lexp-1 in first checking day was obtained a mean of 12.730�0.24% and at batch Lexp-2 12.614�0.22%. Differences between those two batches were insignificant (p[0.05). In case of fat content, at the end of storage period was obtained a mean of 11.256�0.06% for batch Lexp-1 and 11.244�0.11% for batch Lexp-2, differences being insignificant (p [ 0.05). Regarding the profile of amino acids and fatty acids, the mean values obtained during whole storage period oscillated from one stage to another, but the differences between those two batches were insignificant (p [ 0.05). Pasteurized egg melange suffers certain sensorial modifications during storage, especially on consistency and colouring, modifications which are accentuated mainly by storage conditions. Type of polyethylene utilized for this product hadn�t influenced the nutritive qualities of product.


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