Magnesium decreases aluminum accumulation and plays a role in protecting maize from aluminum-induced oxidative stress

Abstract

BackgroundAcidic soils with a pH water below 5.5 occupy up to 40% of world's arable land. Aluminum (Al) toxicity and magnesium (Mg) deficiency often coexist in acidic soils, limiting crop production. In this study, we investigated a role of Mg in alleviation of Al stress in maize (Zea mays) by characterizing the growth responses, Al accumulation and the antioxidant properties of plants cultured hydroponically. MethodsPhysiological and molecular analyses were used to investigate the mechanisms of Mg governing the alleviation of Al-induced ROS production and root growth inhibition. ResultsAluminum (50 µM) decreased root growth and induced oxidative stress. Exogenously added millimolar concentrations of Mg significantly alleviated Al toxicity as evidenced by restoration of plant growth, suppression of Al uptake, and a decline in root H 2 O 2 concentration. Furthermore, the addition of Mg to the Al treatment solution enhanced the activities and expression of genes encoding superoxide dismutase, catalase and peroxidase compared to the Al-only treatment. ConclusionsThe results indicate that Mg plays a role in alleviation of Al toxicity, reduction of Al accumulation and protection from Al-induced oxidative stress through activation of antioxidative enzymes.

Recent Advances in Understanding Mechanisms of Plant Tolerance and Response to Aluminum Toxicity

“…Similarly, Kong et al showed that the addition of Mg to the Al treatment solution alleviated Al-induced inhibition of root growth, suppressed Al uptake, and reduced hydrogen peroxide (H 2 O 2 ) concentration in maize [99]. Furthermore, K + efflux was related to Al tolerance by accompanying OA secretion [99]. Recently, Li et al showed that ectopic expression of either HtNHX1 or HtNHX2, from Jerusalem artichoke (Helianthus tuberosus), could enhance rice tolerance to Al stress and soil acidity by altering K + and H + fluxes and the CW structure [41].…”

“…Further experiment showed that raised pH alleviates Al-induced a decrease in total soluble protein level and an increase in electrolyte leakage in citrus leaves and roots by conferring the ability to maintain a balance between production and detoxification of ROS and methylglyoxal [92]. Moreover, Liu et al's study on wild barley showed that low pH and higher Al tolerance in XZ16 were associated with a higher ability of H + uptake and rhizospheric alkalization [99]. Magnesium promotes the elevated root surface pH regulation in Populus, resulting in root surface alkalization in the transition zone, which alleviates the toxicity of high concentration Al [100].…”

“…Li et al showed that Mg promoted root growth and increased Al tolerance by modulating the production of nitric oxide in Arabidopsis [116]. Similarly, Kong et al showed that the addition of Mg to the Al treatment solution alleviated Al-induced inhibition of root growth, suppressed Al uptake, and reduced hydrogen peroxide (H 2 O 2 ) concentration in maize [99]. Furthermore, K + efflux was related to Al tolerance by accompanying OA secretion [99].…”

Evaluation of Requirements and Efficiency Parameters in the Use, Absorption, and Translocation of Nutrients in the Production of Hymenaea courbaril L. Seedlings, a Fruit Tree of Neotropical Importance

“…Moreover, Mg is fundamental for a series of enzymatic activities and the synthesis of some proteins (Marschner, 2011;Shaul, 2002). Recent studies have also revealed a role of Mg in relieving stress caused by adverse growth conditions, such as aluminum, Mn and Pb toxicity (Bose et al, 2011;Kong et al, 2020;Gransee & Führs, 2013;Shen et al, 2016), photooxidative damage (Cakmak & Kirkby, 2008;Hauer-Já kli & Trä nkner, 2019), and heat stress (Mengutay et al, 2013;Siddiqui et al, 2018).…”

Magnesium in crop production and food quality

“…Similarly, appropriate Mg nutrition mitigates the detrimental effects of Al toxicity in plants. In this Special Issue, Kong et al (2020) show that an adequate Mg supply reduces Al uptake and improves the growth of maize plants exposed to high Al concentrations in the rhizosphere. Increasing Mg supply also increased the antioxidative capacity of maize plants and promoted the expression of genes encoding superoxide dismutase, catalase and peroxidase when plants were exposed to Al stress.…”