scholarly journals Postharvest Application of 1-Methylcyclopropene and Salicylic Acid for Maintaining Quality and Enhancing Antioxidant Enzyme Activity of Apricot Fruits cv. ‘Canino’ During Cold Storage

2018 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Ahmed Abd El-Khalek
2013 ◽  
Vol 61 (1) ◽  
pp. 79-87 ◽  
Author(s):  
N. Sajedi ◽  
M. Boojar

In the present study, three dry land wheat cultivars, Azar 2, Sardary and Rasad, were tested for antioxidant enzyme activity, proline, malondialdehyde (MDA) and dityrosine (DT) content and grain yield after treatment with selenium and salicylic acid (SA). A factorial field experiment was carried out based on a completely randomized block design with three replicates. The experimental factors were three levels of salicylic acid (without SA; seed priming with 0.5 mM SA; seed priming + spraying with 1 mM SA) and two levels of selenium (0 and 20 g/ha). Significant increases in the activity of the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) enzymes and in the proline level were observed after treatment in the leaves of the three genotypes investigated, but this was associated with reduced MDA and DT content. The application of SA as seed priming and the foliar application of Se also increased the grain yield. These results suggest that cultivars exhibiting high antioxidant enzyme activity and proline content under dry land conditions may provide better drought tolerance in wheat.


2020 ◽  
Author(s):  
Lisa Heyman ◽  
Antonios Chrysargyris ◽  
Kristof Demeestere ◽  
Nikolaos Tzortzakis ◽  
Monica Höfte

Abstract BackgroundClimate change will increase the occurrence of plants simultaneously suffering drought and pathogen stress. Although it is well-known that drought can alter the way plants respond to pathogens, knowledge about the effect of concurrent drought and biotic stress in grapevine is scarce. This is especially true for Plasmopara viticola, the causal agent of grapevine downy mildew. This research addresses how vines with different drought tolerance respond to the challenge with P. viticola, drought stress or their combination, and how one stress affects the other. ResultsArtificial inoculation was performed on two cultivars, exposed to full or deficit irrigation, in the Mediterranean climate of Cyprus. In parallel, leaf disks from these plants were inoculated in controlled conditions. Leaves were sampled at an early infection stage to determine the influence of the single and combined stresses on oxidative parameters, chlorophyll, and phytohormones. Under irrigation, the local Cypriot cultivar Xynisteri was more susceptible to P. viticola than the drought-sensitive Chardonnay. The successful infection by P. viticola at 1.5 days post inoculation was associated with high levels of indole-3-acetic acid (IAA), salicylic acid (SA), jasmonic acid (JA), and proline and strong decreases in antioxidant enzyme activity. Drought, on the other hand, triggered the accumulation of IAA and abscisic acid (ABA), which antagonized JA and SA. Exposure to drought stress increased the susceptibility to P. viticola of the leaves inoculated in controlled conditions. Conversely, both cultivars showed resistance against P. viticola when inoculated in planta under continued deficit irrigation. Despite their resistance, the pathogen-associated responses in IAA, antioxidant enzyme activity, and proline still occurred in these drought-stressed plants. Surprisingly, abscisic acid, rather than the generally implicated jasmonic and salicylic acid, seemed to play a prominent role in this resistance. ConclusionsDrought exposure increased the susceptibility of in vitro inoculated leaves. Conversely, deficit irrigation induced resistance to P. viticola in both Chardonnay and Xynisteri when inoculated in planta. ABA, rather than JA and SA, was implicated in this resistance. The irrigation-dependent susceptibility highlights that the changing climate and the practices used to mitigate its effects, may have a profound impact on plant pathogens.


Food Research ◽  
2020 ◽  
Vol 4 (S5) ◽  
pp. 86-95
Author(s):  
N.H. Dolhaji ◽  
I.D. Muhammad ◽  
H. Yaakob ◽  
A. Mohd Marsin

Harvested fruit have high metabolic and moisture content which leads to an active biochemical reaction that contributes to decrement of nutritional value such as vitamin, proteins and lipids. The application of low temperature as a single-effective management to prolong shelf-life of fruits is a common practice which applied to keep agriculture commodities at high quality. A matured stage pineapple is very perishable and cold storage chain is crucial in maintaining the chemical and physical quality attributes in order to assure its commercial value for market. The main objective of this study is to evaluate the effect of sub-optimum cold storage scenario on changes of pineapple fruits physical quality attributes, the activity of browning enzyme and antioxidant related enzyme in 2 pineapple cultivars (cv.), Morris (Queen-type) and Josapine (hybrid of Spanish and Smooth Cayeen). Malaysian pineapple fruit cv. with different sensitivity toward CI, Morris (Queen-type) and Josapine (Smooth-Cayenne-type) were stored at sub-optimal storage temperatures (4±2°C) for 28 days to investigate the effects of CI towards physical quality attributes and antioxidant enzyme activity. The result indicated both cv. was affected with CI towards the 28 days of sub-optimum cold storage. Overall physical quality attributes indicated CI was found positively correlated with the increase of EL and TTA and on the contrary decrease its firmness, weight (% w/w), brightness (L*) and redness (A*). Similarly, a positive correlation was also deduced between CI symptoms and the activities of PPO and APX which reflect the incident of oxidative stress. The results derived from this study may serve as a basis for evaluation of better postharvest strategies to control CI during cold chain storage of pineapple fruits and thus assure the quality and nutritional value till it reaches to consumer.


2020 ◽  
Vol 100 (2) ◽  
pp. 234-243
Author(s):  
Nenzhu Zheng ◽  
Linli Zhang ◽  
Qingwu Xin ◽  
Zhongwei Miao ◽  
Zhiming Zhu ◽  
...  

This study was conducted to evaluate changes to antioxidant systems in the postmortem muscle of three duck breeds and to analyze their relationship with meat quality. Pekin ducks, Muscovy ducks, and Mulard ducks were euthanized at the age of 70 d. The antioxidant enzyme activities and related gene expressions as well as meat quality in muscle tissues were examined. The breed of the duck had a significant effect on the antioxidant capacity of muscle tissues (P < 0.05), with the exceptions of superoxide dismutase (SOD) activity at 96 h as well as total antioxidant capacity (T-AOC) at 120 h. The SOD, glutathione peroxidase (GPx/GSH-Px), and T-AOC activities from highest to lowest were Muscovy duck > Mulard duck > Pekin duck, whereas the malondialdehyde (MDA) concentration followed the opposite pattern. During cold storage (0–120 h), a decrease in the GPx, SOD, and T-AOC activities was noted, although MDA concentration increased gradually. The GPx1 and Cu/Zn-SOD gene expression levels in Muscovy duck muscle tissues were significantly higher than those in other breeds at both 0 and 24 h. Correlation analysis showed that higher antioxidant enzyme activity in duck muscle tissues was associated with higher water-holding capacity (WHC) and more stable meat color. Higher antioxidant enzyme activity in duck meat similarly resulted in higher pH values, higher WHC, and more stable meat color. These data indicate that antioxidant enzymes may inhibit lipid oxidation and participate in the regulation of meat quality.


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