Growth, root and leaf structure, and biomass allocation in Leucanthemum vulgare Lam. (Asteraceae) as influenced by heavy-metal-containing slag

Abstract

Effects of heavy metal contamination on growth, leaf turnover, biomass allocation and leaf and root structure of Leucanthemum vulgare Lam. were investigated. Plants were grown in two outdoor experiments, for 5 weeks or for 3 months, respectively, on sand with different additions of slag containing elevated levels of heavy metals, especially Cu and Ni. In the 3-month experiment nutrients were provided as composted manure, in the 5-week experiment as a solution. Slag contamination reduced plant growth, biomass allocation to roots, specific root length and specific leaf area, while root tissue density and leaf dry matter content increased. Fine root diameter increased, whereas coarse root diameters showed a nonsignificant decreasing trend. Toxicity of slag was lower in the 3-month experiment, probably due to organic matter in the substrate. We conclude that heavy metals in the soil around Cu-Ni smelters may, besides directly reducing growth of the plants, increase their susceptibility to other stresses such as drought, by reducing the root length to leaf area ratio. Fine and coarse roots show distinct responses, indicating that different root diameter classes should be regarded separately to fully understand stress responses of root systems.

Element accumulation, distribution, and phytoremediation potential in selected metallophytes growing in a contaminated area

“…Importantly, some plant species are able to survive in heavy-metalcontaminated environments thanks to their lower sensibility to metal toxicity and successful adaptive response (Ryser and Emerson 2007, Dazy et al 2008, Dazy et al 2009). Obligate or facultative metallophyte species can colonize wastelands connected with mining or smelting activities by spontaneous succession, and the natural vegetation in such areas is an attractive subject matter for researchers (Szarek-Łukaszewska and Grodzińska, 2007).…”

Zn2+-induced changes at the root level account for the increased tolerance of acclimated tobacco plants

“…However, it is still unclear whether photosynthesis inhibition or a perturbation of the water, and thus stomatal limitations, are one of the primary causes of heavy-metal toxicity (including Zn 2+ toxicity) at the shoot level ( Perfus-Barbeoch et al , 2002 ; Sagardoy et al , 2010 ). Increasing evidence suggests that exposure to toxic metal concentrations negatively affects parameters important for plant–water relationships, and, in particular, toxic metal has been found to reduce the biomass allocation to the roots ( Ryser and Emerson, 2007 ) reduce cell-wall elasticity ( Barceló et al , 1986 ) increase cell-membrane permeability ( Llamas et al , 2008 ; Michael and Krishnaswamy, 2011 ); reduce stem and root hydraulic conductivity ( Przedpelska-Wasowicz and Wierzbicka, 2011 ; de Silva et al , 2012 ), and reduce xylem-specific and leaf-specific hydraulic conductivity ( de Silva et al , 2012 ). Hence, given that perturbation of leaf stomatal regulation ( Sagardoy et al , 2010 ) has been considered one of the early causes of heavy-metal toxicity (e.g.…”

Titanium Dioxide Nanoparticles and Sodium Nitroprusside Alleviate the Adverse Effects of Cadmium Stress on Germination and Seedling Growth of Wheat (Triticum aestivum L.)

“…Moreover, it was previously proved that Cd stress adversely limits water uptake by seeds and consequently inhibits germination and seedling growth of wheat [84,85,86]. Cadmium can make plants highly vulnerable to another sort of environmental constraints, such as drought and salinity, due to the reduced water uptake ability of the minor root system [87,88]. Then the plant roots are not able to take up enough water for metabolism, so the plant suffers physiological drought under Cd stress.…”