Effect of tungsten on growth, biochemical constituents, molybdenum and tungsten contents in wheat

Abstract

The effect of various concentrations (3, 9, 27, 81, and 243 mg/kg) of tungsten (W) on growth performance, biochemical constituents and tungsten and molybdenum (Mo) contents in wheat was observed. Lower doses (up to 9 mg/kg) of tungsten showed promotory effects whereas higher doses retarded. An increment in growth, biomass, chlorophyll and carbohydrate contents was observed. Tungsten contents in root and shoot showed a very strong linear dependence on the soil applied W contents. Mo contents in plant tissue showed an increase with an increase in the W contents in plant tissue up to a threshold after which it showed an abrupt decrease. The activity of peroxidase enzyme decreased with lower application of W. Higher administration of tungsten (27-243 mg/kg) resulted in increased total phenol, free proline and activity of enzyme peroxidase.

Influence of Increasing Tungsten Concentrations and Soil Characteristics on Plant Uptake: Greenhouse Experiments with Zea mays

“…At the tungsten concentrations used in this experiment, no differences in biomass production were found between the control and tungsten enriched soils. The results are in agreement with previous findings for another species, Triticum aestivum, which reported that biomass was not influenced by low tungsten concentrations in soil [34,35]. A reduction in biomass production was discovered in soils only with very high tungsten concentrations of up to 5000 mg kg −1 for Glycine max [30] and 2600 mg kg −1 for Helianthus annuus [26].…”

“…There are few studies on tungsten uptake by plants and the reported tungsten concentrations in plants are highly variable due to the differences between plant species and experimental conditions [26,30,34]. Although in hydroponic experiments, the tungsten uptake can be directly linked to the concentration of metal in solution and to specific tolerance mechanisms, the interpretation of the phytoavailability in soil is more complex since it is essentially determined by tungsten species in the soil liquid phase.…”

Tungsten Distribution in Soil and Rice in the Vicinity of the World's Largest and Longest-Operating Tungsten Mine in China

“…Several previous studies observed the dependence of plant W content on the soil W contents [3], [18], [28]–[30]. Previous experiments in field showed W contents in the roots and leaves of maize were significantly correlated with the W content in the soil adjacent to an old tungsten mine (Pechtelsgrün) in Germany [18].…”

“…This order is similar to that for wild Calluna Vulgaris , Taraxacum officinale , and Trifolium pretense reported by Wilson and Pyatt [15] and Jiang et al [18] , i.e., W content in root > W content in leaf > W content in stem. In addition, content and enrichment in the root of Sunflowers, Ryegrass(Lolium perenne), Nothofagus menziesii , wheat , and cowpea growing in W-spiked soils were also higher than those in their leaves [2] , [12] , [20] , [28] , [29] . The common range of W in terrestrial plants was <0.001 to 0.15 mg kg −1 [6] .…”

Tungsten Toxicity in Plants

“…W is uptaken by the roots and translocated to the upper plant organs via the xylem. W accumulation in the root tissues is much higher than in the shoot [ 4 , 34 , 35 ]. Anthocyanins may also facilitate W accumulation in some plant species [ 36 ].…”