Nickel accumulation and its effect on growth, physiological and biochemical parameters in millets and oats

Abstract

With the boom in industrialization, there is an increase in the level of heavy metals in the soil which drastically affect the growth and development of plants. Nickel is an essential micronutrient for plant growth and development, but elevated level of Ni causes stunted growth, chlorosis, nutrient imbalance, and alterations in the defense mechanism of plants in terms of accumulation of osmolytes or change in enzyme activities like guiacol peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD). Ni-induced toxic response was studied in seedlings of finger millet, pearl millet, and oats in terms of seedling growth, lipid peroxidation, total chlorophyll, proline content, and enzymatic activities. On the basis of germination and growth parameters of the seedling, finger millet was found to be the most tolerant. Nickel accumulation was markedly lower in the shoots as compared to the roots, which was the highest in finger millet and the lowest in shoots of oats. Plants treated with a high concentration of Ni showed significant reduction in chlorophyll and increase in proline content. Considerable difference in level of malondialdehyde (MDA) content and activity of antioxidative enzymes indicates generation of redox imbalance in plants due to Ni-induced stress. Elevated activities of POD and SOD were observed with high concentrations of Ni while CAT activity was found to be reduced. It was observed that finger millet has higher capability to maintain homeostasis by keeping the balance between accumulation and ROS scavenging system than pearl millet and oats. The data provide insight into the physiological and biochemical changes in plants adapted to survive in Ni-rich environment. This study will help in selecting the more suitable crop species to be grown on Ni-rich soils.

Evaluation of the protective role of exogenous growth regulators against Ni toxicity in woody shrub Daphne jasminea

“…Toxicity of Ni to plants was attributed to detrimental effects caused by water, osmotic, and oxidative stresses (Yusuf et al 2011; Gupta et al 2017). In our study on D. jasminea toxicity, increasing Ni concentrations were manifested by inhibited growth, proliferation, and organogenesis.…”

“…In recent years, the accumulation of Ni in environment increased due to anthropogenic activities; thus far, more often plants suffer from excess of Ni rather than from its deficiency (Yusuf et al 2011). Nickel excess is toxic to the majority of plant species, and it causes growth retardation as a result of versatile metabolic disturbances, such as oxidative stress, osmotic and nutrient imbalance, chlorosis and related photosynthesis inhibition, as well as decreased enzymatic activity (Pietrini et al 2015; Matraszek et al 2016; Gupta et al 2017). In natural sites, Ni occurs in high concentrations in ultramafic (serpentine) soils, where local flora developed unique adaptations to cope with elevated level of Ni, resulting in increased tolerance and/or hyperaccumulation.…”

Tetrahydrocurcumin Provides Neuroprotection in Experimental Traumatic Brain Injury and the Nrf2 Signaling Pathway as a Potential Mechanism

“…MDA is considered the index of lipid peroxidation [21]. In addition, GPx and SOD are antioxidant enzymes, involved in the catalytic detoxification of superoxide and hydrogen peroxide [22, 23]. The conversion content of MDA, and the activity of GPx and SOD in the rat cortex samples proved that oxidative stress occurred following TBI [24, 25].…”

Nickel Carcinogenesis Mechanism: DNA Damage

“…Numerous in vitro and in vivo studies have shown that Ni and Ni compounds can induce ROS accumulation and oxidative stress [76,77,78,79,80,81,82,83]. Ni and Ni compounds induce ROS accumulation in two ways: (i) increasing ROS generation and (ii) impairing the antioxidant system [84,85].…”