High Ni Levels in Soil Can Modify Growth Performance and Mineral Status of Wheat Cultivars

Abstract

Nickel (Ni) contamination in soil is a widespread problem in this era of industrial development. Plant cultivars respond differentially to Ni contamination in soil. In the present study, we have investigated the effect of different Ni levels to the growth and mineral status of two wheat cultivars (Sehar‐2006 and LU‐26). Five different levels of Ni as NiSO4 · 4 H2O (0, 30, 45, 60, and 75 mg kg−1) were applied to soil in the pots. LU‐26 performed better compared to Sehar‐2006 in terms of dry weight production and physiological parameters. LU‐26 contained higher Ni in roots compared to Sehar‐2006, but the Ni concentration in shoots of both the cultivars was similar. LU‐26 translocated less Ni toward the shoot compared to Sehar‐2006 indicating the exclusion of Ni from shoots and retaining it in roots by LU‐26 as evident from bioconcentration and translocation factors. Contradictly, Sehar‐2006 translocated more Ni from root to shoot indicating its tolerance to Ni. Ni increased manganese (Mn) in shoots of Sehar‐2006 and LU‐26 up to 60 and 30 mg kg−1, respectively. Ni decreased copper (Cu) and zinc (Zn) concentration in shoots of both cultivars, however Zn concentration in roots increased at all levels of Ni. LU‐26 excluded Ni from shoots and Sehar‐2006 accumulated Ni in shoots. The present study helps in understanding the process of metal uptake and distribution during the early growth stages of the plant and can signify overall potential of a crop for its exploitation on contaminated soils.

Alleviating Effect of Calcium on Nickel Toxicity in Rice

“…c) and the dysfunctional membrane integrity triggered by extracellular peroxidase activity due to Ni toxicity. These are the main reasons of higher Ni concentrations in plant . Generally, Ca decreased the absorption of Ni and other divalent metals and the current results confirm these findings, as a decrease in Ni in plants due to Ca addition to the rooting medium was recorded (Fig.…”

“…Ni 40 Ca 0 exhibited the maximum increase (11-fold) in Ni concentration in roots compared to control (Ni 0 Ca 0 ) and the extent of increase was lowered to five-fold with Ca addition (Ni 40 Ca 160 ) indicating the reducing effect of Ca against Ni toxicity. The increase in the Ni concentration of plants due to application of Ni at different levels has been reported in fenugreek [56], maize [57], wheat [58] and barley [59]. Obviously, the increased availability of Ni at higher Ni levels was evidenced by high AB-DTPA extractable Ni (Fig.…”

“…It could be observed that Ni decreased the SDW and RDW of rice plants compared to the control (Ni 0 Ca 0 ). A decrease in the dry matter production of plants due to Ni can be attributed to its adverse effect on leaf photosynthetic and transpiration activities, chlorophyll content, impaired membrane and oxidative damage to plant tissues, subsequently resulting in decreased plant growth . Membranes are primary sites of metal toxicity and supply of additional Ca stabilizes the membrane, thereby alleviating Ni toxicity and enhancing the plant growth .…”

“…Naturally, Ni is derived from ultramafic rocks in serpentinic soils while anthropogenic sources include coal combustion, fuel, Ni/Cd batteries, sewage sludge, vegetable oil industries, Ni plating and agro‐chemicals . Excessive Ni values in plants inhibit photosynthesis by disturbing the electron transport chain and assimilation of CO 2 and stomatal conductance . However, the absorption and accumulation of Ni in the edible parts of plants contaminate the food chain, thus threatening human health .…”

Comparison of Fine and Coarse Rice Varieties for Nickel Accumulation and Growth Response at Different Levels of Nickel

“…[13] Plant species differ greatly in response to trace metals like cadmium (Cd) and Ni which is evident from inter-and intra-specific differences. [14,15] Different plants have the capacity to accumulate higher concentrations of metals without decreasing their growth while others simply screen out the metals at root level. Trace metals tolerance of field crops is variable, and evidence of intra-species genetic variations exists among different plants.…”