Comparative study of methodologies to determine the antioxidant capacity of Al-toxified blueberry amended with calcium sulfate

Abstract

Blueberry (Vaccinium corymbosum L.) is well adapted to acidic soils where aluminum (Al 3+ ) can be linked to oxidative stress and antioxidant capacity (AC). Calcium sulfate (CaSO 4 ) is used to alleviate Al 3+ because it does not alter soil acidity. However, the role of Ca addition in AC, based on a single electron transfer reaction (SET), remains unknown. The aim was to evaluate the AC using SET methodologies, i.e., 2,2-diphenyl-2-picrylhydrazyl (DPPH), 2,2´-Azinobis-bis (3 ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing-antioxidant power (FRAP). Bueberry cultivars Elliot and Jersey were grown and exposed to the following treatments for 15 days: Control (nutrient solution alone, pH 4.5); control+Al (Al); control+Al+Ca (Al+Ca) and control+Ca (Ca). The Ca and Al concentrations, total phenol (TP) content and radical scavenging activity (RSA) were evaluated at 7 and 15 days. The Al+Ca and Ca treatments increased the Ca concentration in the leaves (22%) and roots (40%) of both cultivars compared with the control. The Ca in the tissues varied with cultivar and time. After 15 days, increases in TP, DPPH, ABTS and FRAP were detected. The cultivars showed positive relationships between the TP and AC in the leaves and roots. Thus, CaSO 4 is an important tool to improve the AC in Al-stressed fruit crops grown in acid soils.

Protective Effect of Methyl Jasmonate on Photosynthetic Performance and Its Association with Antioxidants in Contrasting Aluminum-Resistant Blueberry Cultivars Exposed to Aluminum

“…At the cellular level, the primary target of Al 3+ is the plasma membrane and organelle, where Al 3+ binds to the negative-charged phospholipids leading to a reduction of membrane fluidity (Meriño-Gergichevich et al 2010), disrupting the membrane functions, which may lead to an increase of reactive oxygen species (ROS) and thereby oxidative stress and lipid peroxidation (LP) (Inostroza-Blancheteau et al 2008). To counteract the Al toxic damage induced by oxidative stress, plants can activate antioxidant systems (Inostroza-Blancheteau et al 2008;Meriño-Gergichevich et al 2015). Enzymatic activities as catalase (CAT), peroxidase (APX), and superoxide dismutase (SOD) and non-enzymatic compounds have been reported as ROS scavengers in the Al detoxification in many plants (Inostroza-Blancheteau et al 2008;Meriño-Gergichevich et al 2015).…”

Chemical, antimicrobial, and molecular characterization of mortiño (Vaccinium floribundum Kunth) fruits and leaves

“…A positive correlation was observed between polyphenols and anthocyanins, whereas a negative correlation between the antioxidant capacity and polyphenol levels was detected. Positive correlations between anthocyanin and polyphenol contents have previously been observed (Prencipe et al., ), but negative correlations between polyphenols and antioxidant capacity are not in agreement with recent findings that suggest a strong positive correlation between both compound classes in fruits and leaves of other species of Vaccinium (Meriño‐Gergichevich et al., ). However, negative correlations between polyphenols and antioxidant capacity have been observed in other fruits like guava (Vasco, Ruales, & Kamal‐Eldin, ).…”

Interactions Between Acidic (Al3+, Fe2+) and Basic (Ca2+, Mg2+) Cations in Oxisol and Ultisol under Acidification Induced by Simulated Acid Rain

“…Interactions of extractable aluminum with exchangeable bivalent base cations: Figs 15 . Aluminum in the soils increased due to the mobilization as the pH of simulated acid rain and soil decreased 16 .…”