Selenium and silicon reduce cadmium uptake and mitigate cadmium toxicity in Pfaffia glomerata (Spreng.) Pedersen plants by activation antioxidant enzyme system

Abstract

Cadmium (Cd) is toxic to plants and animals, making it necessary to develop strategies that seek to reduce its introduction into food chains. Thus, the aim of this study was to investigate whether silicon (Si) and selenium (Se) reduce Cd concentrations in Pfaffia glomerata medicinal plant and attenuate the oxidative stress promoted by this metal. These plants were cultivated in hydroponics under the following treatments: control (nutrient solution), 2.5 μM Se, 2.5 mM Si, 50 μM Cd, 50 μM Cd + 2.5 μM Se, 50 μM Cd + 2.5 mM Si. After 14 days of exposure to treatments, leaves and roots were collected for the determination of dry weight of shoot and roots, Cd concentrations, chlorophyll and carotenoids content, and biochemical parameters (lipid peroxidation and guaiacol peroxidase and superoxide dismutase activities). The data were submitted to analysis of variance and means were compared with Scott-Knott test at 5% error probability. Roots of P. glomerata plants showed a significant reduction on dry weight accumulation when exposed to Cd. However, both Se and Si promoted a significant reduction of deleterious effects of Cd. The Cd concentrations in the tissues were reduced in the presence of Se or Si. Plants treated with Cd together with Se or Si presented higher pigment content than those with only Cd, thus showing a reduction in the negative effects caused by this element. In the treatments in which Se and Si were added in the growth medium together with Cd, an activation of superoxide dismutase and guaiacol peroxidase enzymes was observed in the roots and shoot, which may have contributed to lower lipid peroxidation. Thus, Se and Si reduce Cd concentrations and have potential to ameliorate Cd toxicity in P. glomerata plants, which can be used to increase productivity and quality of medicinal plants.

Selenium and silica nanostructure-based recovery of strawberry plants subjected to drought stress

“…It seems that these elements protect chloroplast structure against severe oxidative damage such as destruction of both grana and stroma lamellae, and increase the biosynthesis of photosynthetic pigments by protecting chloroplastic enzymes 33 . Probably, these elements act as cofactors in many enzymatic reactions involved in the biosynthetic pathways of the chloroplast 36 , 37 .…”

Role of Ferrous Sulfate (FeSO4) in Resistance to Cadmium Stress in Two Rice (Oryza sativa L.) Genotypes

“…Residues from smelting industries, metalliferous mines, oil burning in automobiles, tire dust, Cd containing batteries, polyvinyl plastic, canned foods, metal ice trays, meat processing, wrappings bags, and municipal sewage incineration are sources of Cd pollution that ends up in the wastewater [ 2 , 9 , 19 , 25 , 52 ]. The fact that Cd is non-vital for plant development, but is easily taken up by plant roots and shoots, makes it a metal of utmost concern regarding its accumulation in the food chain [ 2 , 22 , 24 , 26 , 28 , 29 ]. Photosynthesis, respiration, cell division, water relations, opening and closing of stomata, nitrogen metabolism, and mineral nutrition are the main metabolic processes within the plants, which are negatively affected by Cd stress [ 14 , 21 , 26 , 52 ].…”

“…Over-production of ROS is toxic, and plants need to scavenge those immediately through an antioxidative defense system [ 14 , 26 ]. Previously, antioxidative enzymes played a significant role in the reduction of Cd phytotoxicity in Glycine max [ 21 ], Solanum lycopersicum [ 27 ], Pfaffia glomerata [ 28 ], Oryza sativa [ 29 ], Boehmeria nivea [ 20 ], and Zea mays [ 30 ] grown under excessive Cd concentrations.…”

Aluminum stress tolerance in potato genotypes grown with silicon

“…In this context, silicon (Si) is a beneficial element for some plants and has been effective in reducing the peroxidation of membrane lipids (Etesami and Jeong 2018). This is due to the Si effect on the enzymatic and non-enzymatic antioxidant system of the plant, thus showing potential to be used in the alleviation of stress caused by toxic metals (Farooq and Dietz 2015;Dorneles et al 2017;Pereira et al 2018a), mainly Al (Camargo et al 2014;Haynes 2017;Jesus et al 2017). This potential is also supported by the high affinity that Si has with various metals, performing a coprecipitation of Si metal complexes in the cell wall.…”