344 research outputs found

    Effects of salinity on antioxidant system in four grape (Vitis vinifera L.) genotypes

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    Salinity is a major environmental stress that restricts plants growth and production. Grapes are classified as moderately sensitive to salinity. The aim of this work was to investigate the salinity effects on lipid peroxidation level, antioxidant compounds and anti-oxidative enzymes activities and photosynthetic pigment contents in four grape genotypes that are commonly grown in the region around Urmia salt lake. Malondialdehyde content and protective enzymes activities in roots and leaves of four genotypes increased significantly (P < 0.05) under salinity. 'Chawga' showed lower and higher increases in malondialdehyde content and enzymes activities, respectively. Salinity had an obvious effect on the accumulation of total phenolics content and induced phenylalanine ammonia-lyase enzyme activity in all genotypes. There were significant positive correlations (P < 0.01, r2= 0.838) between anti-oxidative enzyme activities, total phenolics content and phenylalanine ammonia-lyase activity in the leaves of all genotypes. Chlorophyll a, b contents in leaves of all genotypes were reduced and carotenoid content increased significantly (P < 0.05) under salinity. 'Chawga' showed a lower decrease in chlorophyll content and a higher increase in carotenoid content than others. It seems that 'Chawga' had a better antioxidant system compared to other genotypes and showed a higher capacity to tolerate salinity.

    Effects of salinity on potassium absorption and expression of K+transporter genes at different concentrations of potassium in Grape (Vitis vinifera L.)

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    Grapevine is classified as a moderately sensitive plant to salinity. Hydroponically three grape genotypes (Vitis vinifera L.) were treated with different concentrations of KCl (0.1, 0.3, 0.5, 1, 5, 10 mM KCl) and NaCl (0, 25, 50,100 mM NaCl). Cl- and Na+ contents were significantly increased in different plant organs of all the genotypes under salinity. In this study, sensitive ('GhezelUzum'), tolerant ('Gharashani') and semi-resistant ('Chawga') grape genotypes were selected based on screening experiments under salinity. 'Gharashani' accumulated higher Na+ and Cl- in roots compared to the sensitive one. 'Chawga' accumulated high K+ similar to Na+ in root and shoot even at high salinity. Km calculation for K+ and Na+ uptake in root and shoot of 'Chawga' showed that K+ and Na+ compete to enter the plant through roots. Two KUP/KT/HAK-type potassium transporters are expressed highly in the grapevine during stress. VvK1.1 could play a major role in K+ loading into grape tissues. The expression of VvKUP1 and VvKUP2 transporters and VvK1.1 channel in roots of 'Chawga' genotype increased significantly (P < 0.05) at different KCl concentrations under salinity stress. Our results showed a significant difference between tolerant and sensitive genotypes and highlighted a strong relationship between the accumulation of specific transcripts and the degree of salinity tolerance

    Leaf water potential, photosynthetic pigments and compatible solutes alterations in four grape cultivars under salinity

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    A hydroponic culture experiment was conducted to investigate the effects of different concentrations (0, 25, 50 and 100 mM) NaCl on own-rooted table grape (Vitis vinifera L.) cultivars (red 'Rishbaba', red 'Sahebi', 'Dastarchin' and red 'Sultana') under greenhouse conditions. Cultivars were evaluated for growth analysis leaf area, leaf water potential and the chlorophyll a, b and carotenoid contents in relation to proline and soluble sugars accumulation. Salinity treatments caused a growth reduction (P ≤ 0.05) in all the cultivars. Also leaf water potential and chlorophyll a, b contents decreased whereas carotenoid, proline and soluble sugars increased with increasing NaCl concentration. 'Dastarchin' and red 'Sultana' showed the salt- sensitivity, the highest loss of growth, leaf water potential and chlorophyll content and the lowest accumulation of carotenoids, proline and soluble sugars. Also salt stress significantly (P < 0.001) increased the rate of lipid peroxidation in the all cultivars particularly in 'Dastarchin' and red 'Sultana'. The increase in malondialdehyde content indicated that salinity induced oxidative stress. There was a significant negative correlation between leaf water potential and NaCl concentrations (r2: -0.781, p < 0.001). A positive correlation was also found between lamina proline contents and NaCl concentrations (r2: +0.964, p < 0.001) for all salinity treatments. Considering overall results red 'Rishbaba' and red 'Sahebi' showed higher capacity to tolerate salinity when compared to 'Dastarchin' and red 'Sultana'.

    Short term response of grapevine grown hydroponically to salinity: Mineral composition and growth parameters

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    The response of hydroponically grown four ownrooted table grape (Vitis vinifera L.) cultivars ('Red Rishbaba', 'Red Sahebi', 'Dastarchin' and 'Red Sultana') to different salt concentrations (0, 25, 50 and 100 mM NaCl) was studied under greenhouse condition. Growth parameters, total chlorophyll (a+b) and proline contents were determined in leaves and roots. Cl-, Na+, K+ and NO3 - concentrations were measured in lamina, petiole, stem and root. Shoot growth, total dry weight, total leaf chlorophyll (a+b), NO3 --N and K+ contents were significantly reduced (P≤0.05) under NaCl stress, whereas proline, Cl- and Na+ accumulation increased significantly with increasing salinity. 'Red Rishbaba' and 'Red Sahebi' showed a less decrease in total leaf chlorophyll, K+ and NO3 - contents, while proline accumulation in these cultivars was higher than that of 'Dastarchin' and 'Red Sultana'. Also, shoots of 'Red Sahebi' and 'Red Rishbaba' accumulated lower Cl- and Na+ than other cultivars. In conclusion, the overall results showed that 'Red Rishbaba' and 'Red Sahebi' were more tolerant than 'Dastarchin' and 'Red Sultana'.

    Ameliorative effects of salicylic acid on mineral concentrations in roots and leaves of two grapevine (Vitis vinifera L.) cultivars under salt stress

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    Salicylic acid (SA) acts as an endogenous signal molecule, synchronizing plant responses under abiotic stress and a component of tolerance in plants. The current study investigates the effects of SA on mineral nutrient concentrations in two grapevine (Vitis vinifera L.) cultivars, 'Qarah Shani' and 'Thompson Seedless' under NaCl stress. Grapevine rooted cuttings were planted in pots, containing a mixture of perlite and cocopeat (1:1 v/v) and placed in an open hydroponic system. Plants were exposed to five levels of salinity 0, 25, 50, 75 and 100 mM NaCl and four levels of SA 0, 100, 200 and 300 mg∙L-1. Results indicated that foliar spray with SA improved nutrient uptake by grape roots. Plant’s leaves and roots Na+ and Cl- contents increased significantly, and NO- 3-N, K+, Na+, Ca2+, Mg2+, Zn2+, Fe2+ and also K+/Na+ selectivity ratios decreased in both cultivars in response to salt treatments. Application of SA significantly reduced Na+ and Cl- accumulation in leaves and roots in both cultivars and it increased NO3-N, K+, Ca2+, Mg2+, Zn2+ and Fe2+ contents under NaCl stress. Therefore, SA could mitigate the detrimental effects of salinity on accumulation of harmful ions and improve the absorption of essential and beneficial elements in grapevine under salinity.

    The Effects of Dietary Polyphenols on Circulating Cardiovascular Disease Biomarkers and Iron Status:A Systematic Review

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    The prevalence of cardiovascular disease (CVD) is rising worldwide, remaining the major cause of death in developed countries. Polyphenols have been shown to have cardioprotective properties; however, their impact on iron bioavailability and potential impact on other aspects of health is unclear. A systematic review was undertaken to evaluate the current status of the relationship between habitual polyphenol consumption, iron status, and circulating biomarkers of CVD. Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2009 guidelines, searches were performed across 5 electronic databases (PubMed, Cochrane Library, Scopus, Web of Science, and CINAHL) to identify randomized controlled trials which investigated the effects of polyphenol consumption on inflammatory markers, serum lipid profile, and iron absorption and bioavailability. In total, 1174 records were identified, with only 7 studies meeting the inclusion criteria. The selected studies involved 133 participants and used a variety of foods and supplements, including olive oil and cherries, rich in polyphenols including hydroxytyrosol, quercetin, and resveratrol, as well as catechin enriched drinks. The duration of the studies ranged from between 56 and 145 days, with total polyphenolic content of the food items and supplements ranging from 45 to 1015 mg (per 100 g). Polyphenols did not appear to interfere with iron status, and most studies reported improvements in inflammatory markers and lipid profile. While these results are promising, the limited number of studies and considerable heterogeneity across the interventions support the need for more extensive trials assessing the relationship between polyphenol intake, iron bioavailability, and CVD risk

    Iron therapy substantially restores qEEG maturational lag among iron-deficient anemic infants

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    Objective: To use quantitative electroencephalography (qEEG) to assess the impact of iron-deficiency anemia on central nervous system maturation in the first year of life. Method: Twenty-five infants (3–12 months old) presenting ferropenic anemia (IDA) and 25 healthy controls (CTL1), matched by age/gender with the former, were studied in two stages. Electroencephalogram during spontaneous sleep was recorded from all participants; the fast Fourier transform was calculated to obtain absolute power (AP) and relative power (RP) qEEG measures. In the first stage, a qEEG comparison between CTL1 and IDA was performed. Second stage consisted in comparing qEEG of the IDA infants before and after supplementation with iron (IDA-IS group), and comparing qEEG of the IDA-IS group with another control age-matched group (CTL2). Non-parametric multivariate permutation tests (NPT) were applied to assess differences between CTL1 and IDA groups, as well as IDA vs. IDA-IS, and IDA-IS vs. CTL2. Results: More power in slow frequency bands and less power in fast frequency bands in 64% of IDA babies were observed. NPT evinced higher alpha AP and RP (P < 0.001), less theta AP, and less delta and theta RP in CTL1 than in IDA. After iron-restoration therapy, alpha AP and RP increased while theta AP and theta and delta RP decreased, reaching almost normal values. Discussion: This work reveals CNS developmental delay through the study of qEEG (less rapid and more slow frequencies) which recovered significantly with iron supplementation. It is concluded that IDA constitutes a high risk factor for a lag of CNS maturation.CONACYT-Project No. CO1/40257-A1

    Aerosols in atmospheric chemistry and biogeochemical cycles of nutrients

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    Atmospheric aerosols have complex and variable compositions and properties. While scientific interest is centered on the health and climatic effects of atmospheric aerosols, insufficient attention is given to their involvement in multiphase chemistry that alters their contribution as carriers of nutrients in ecosystems. However, there is experimental proof that the nutrient equilibria of both land and marine ecosystems have been disturbed during the Anthropocene period. This review study first summarizes our current understanding of aerosol chemical processing in the atmosphere as relevant to biogeochemical cycles. Then it binds together results of recent modeling studies based on laboratory and field experiments, focusing on the organic and dust components of aerosols that account for multiphase chemistry, aerosol ageing in the atmosphere, nutrient (N, P, Fe) emissions, atmospheric transport, transformation and deposition. The human-driven contribution to atmospheric deposition of these nutrients, derived by global simulations using past and future anthropogenic emissions of pollutants, is put into perspective with regard to potential changes in nutrient limitations and biodiversity. Atmospheric deposition of nutrients has been suggested to result in human-induced ecosystem limitations with regard to specific nutrients. Such modifications favor the development of certain species against others and affect the overall functioning of ecosystems. Organic forms of nutrients are found to contribute to the atmospheric deposition of the nutrients N, P and Fe by 20%–40%, 35%–45% and 7%–18%, respectively. These have the potential to be key components of the biogeochemical cycles since there is initial proof of their bioavailability to ecosystems. Bioaerosols have been found to make a significant contribution to atmospheric sources of N and P, indicating potentially significant interactions between terrestrial and marine ecosystems. These results deserve further experimental and modeling studies to reduce uncertainties and understand the feedbacks induced by atmospheric deposition of nutrients to ecosystems
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