Nickel stressed responses of rice in Ni subcellular distribution, antioxidant production, and osmolyte accumulation

Abstract

Nickel has been found a key pollutant in farmlands of central and south China, and understanding of Ni toxicity in rice is of great significance in safety production of rice and remediation of Ni polluted paddy soils. The present study aimed to investigate the uptake and subcellular distribution of Ni, antioxidant production, and osmolyte accumulation of rice (Oryza sativa L., cv. yangliangyou 6) plants exposed to excessive Ni concentrations to gain an insight into Ni-induced phytotoxicity. Results revealed that exposure of rice seedlings to high Ni concentrations resulted a decline in root and shoot lengths and fresh weight (FW) and dry weight (DW) of rice plants, which are in connection with the depletion of the contents of photosynthetic pigments. Measurement of Ni concentrations in the roots and shoots showed that Ni was mainly accumulated in roots followed by shoots. Moreover, Ni was mainly deposited in soluble fraction and cell wall, than cell organelle, which suggests that both compartments act as crucial defensive barriers against Ni toxicity in rice plants. Ni also induced its toxicity by damaging oxidative metabolism, as indicated by increased level of hydrogen peroxide and malondialdehyde content. Furthermore, Ni stress also showed a desynchronized antioxidant system by increasing the activities of catalase, peroxidase, and the contents of ascorbic acid and glutathione, whereas decreasing the activity of superoxide dismutase in the roots and shoots of rice plants. Ni stress also triggered the rate of proline accumulation and decreasing the contents of soluble protein and soluble sugar. In crux, our results suggests that excessive Ni inhibited rice growth and induced oxidative stress through inducing ROS formation, while stimulated enzymatic and non-enzymatic antioxidants system appeared as adaptive mechanisms of rice plants against Ni-induced oxidative stress. Furthermore, majority of Ni was located in soluble fraction and modulation in osmolyte accumulation under Ni stress seemed to provide additional defense against oxidative stress.

Effect of Vanadium on Growth, Photosynthesis, Reactive Oxygen Species, Antioxidant Enzymes, and Cell Death of Rice

“…Generally, ROS induced in the plant as a result of reaction among fatty acid and heavy metal (Shah et al 2001). The H 2 O 2 is an important component of ROS, and maximum produced when plants interact with heavy metals (Rizwan et al 2017). Our findings illustrated that H 2 O 2 production in rice seedlings was higher in response to increase the V concentration but the highest H 2 O 2 production was noted at 70 V mg L −1 .…”

The assessment of cadmium, chromium, copper, and nickel tolerance and bioaccumulation by shrub plant Tetraena qataranse

“…Following cationic exchange for metals via the functional groups, alteration of lignin, cellulose and protein structural moieties leads to changes in the plant’s growth pattern, photosynthetic activity and antioxidant system 24,57 . Indeed, several studies reported single and combined effects of these metals (Cd, Cr, Cu, Ni and Pb) 58–61 on photosynthetic activity, proline content and soluble sugars. Others are increased activities of total glutathione, ascorbate, peroxidase, superoxide dismutase and catalase in plant species including B. juncea, K. obovata, O. sativa, S. drummondii .…”

Sodium Nitroprusside Mitigates the Inhibitory Effect of Salt and Heavy Metal Stress on Lupine Yield and Downregulates Antioxidant Enzyme Activities

“…Rapid industrialization is one of the main causes of environmental pollution, caused by the release of significantly large amounts of toxic metals, including nickel (Ni) (Rizwan et al, 2017). Ni is released into the environment from various anthropogenic activities, including metal mining and smelting, the burning of fossil fuels, vehicle emissions, the disposal of household and industrial wastes, and the application of fertilizers (Chen et al, 2009).…”

“…Ni is released into the environment from various anthropogenic activities, including metal mining and smelting, the burning of fossil fuels, vehicle emissions, the disposal of household and industrial wastes, and the application of fertilizers (Chen et al, 2009). The amount of Ni in normal soils ranges from 10 to 1,000 mg kg −1 , but in high concentrations can cause substantial toxic effects on plants, including the inhibition of seed germination, reduction in plant growth and yield (Shukla & Gopal, 2009), induction of leaf chlorosis, necrosis, and wilting (Mosa et al, 2016), and peroxidation of lipids (Rizwan et al, 2017).…”