Phytotoxicity of Cyanide to Weeping Willow Trees

“…In spite of capabilities of plants to take up both species of free cyanide and iron cyanides readily, great differences in the uptake pathway between these species have been observed (Larsen et al 2004(Larsen et al , 2005Yu et al 2005aYu et al , b, 2007Yu et al , 2008Yu and Gu 2009). Unlike botanical uptake of heavy metals fitting to the saturation kinetics, which is typically used to represent proteinmediated uptake mode (Cohen et al 1998), free cyanide behaves differently from heavy metals and requires different strategies.…”

Section: Uptake and Transport Of Cyanide By Plantsmentioning

confidence: 99%

“…Indeed, phytotoxicity of cyanides has been observed at multiple levels, from reduced growth rate, through effects on biomass, transpiration rate and chlorophyll content, to inhibition on enzymatic activities (Larsen et al 2005;Yu et al 2005aYu et al , 2008Yu and Gu 2009). It has been proposed that the possible mechanism involved in phytotoxicity of cyanide is generally ascribed to formation of complexes with metal ions in the enzyme cytochrome oxidase (Solmonson 1981).…”

Section: Phytotoxicity Of Cyanogenic Compoundsmentioning

confidence: 99%

“…Levels of 2 mg CN/L in hydroponic solution are toxic to willows (Salix viminalis) with a 50 % depression in transpiration after 72-h exposure, while levels C20 mg CN/L are immediately lethal (Larsen et al 2004). EC 50 values for weeping willows (Salix babylonica L.) were estimated to be between 3.27 and 8.23 mg CN/L using normalized transpiration rate as a sensitive endpoint for toxicity determination (Yu et al 2005a). In contrast, no negative influence on transpiration and growth of diamond willow (Salix eriocephala var.…”

Section: Phytotoxicity Of Cyanogenic Compoundsmentioning

confidence: 99%

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Uptake, assimilation and toxicity of cyanogenic compounds in plants: facts and fiction

2014

Int. J. Environ. Sci. Technol.

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Cyanide is a simple nitrogenous compound that arises from both anthropogenic and natural sources. Plants vary considerably in their physiological and biochemical responses to different species of exogenous cyanides from reduced growth to inhibition on enzymatic activities. Also, great differences in uptake, assimilation and toxicity between free cyanide and iron cyanide have been observed. Unlike botanical uptake of free cyanide chiefly achieved by simple diffusion, iron cyanides have long been considered membrane impermeable and a protein-mediated uptake mode has been proposed. Biological fate of cyanides in plant materials is highly dependent on speciation of cyanides present. Natural development of degradation of free cyanide in plants is very obvious, where the b-cyanoalanine pathway has been widely distributed in higher plants and the production of asparagine and aspartate associated with cyanide assimilation is suggestive. Because phytodissociation of iron cyanides into free cyanide in plant materials is not a mandatory process involved in phytoassimilation, plants probably metabolized them through an undiscovered degradation pathway rather than the b-cyanoalanine pathway. Available information shows phytoassimilation of endogenous cyanide into nitrogen metabolism; however, additional efforts to fully elucidate presence of essential enzymes involved and their proteomic or DNA expression quantitatively are needed to prove and clarify phyto-benefits of assimilation of exogenous cyanide in plant nutrition.

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“…With this test, a series of organic and inorganic compounds has been tested (Larsen et al 2005, Larsen and Trapp 2006, Ucisik et al 2007, Yu et al 2005. …”

Section: Tree Toxicity Testmentioning

confidence: 99%

Insignificant acute toxicity of TiO2 nanoparticles to willow trees

et al. 2008

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Goal, Scope and Background. Manufactured nanoparticles are expected to increase in production in near future. In response, their environmental fate and effects are intensively studied. Phytotoxicity of some types of nanoparticels has been observed for annual species in the seed germination and root elongation test. Yet, no results of toxicity tests with trees have been reported. Woody species, dominant in many ecosystems, may be in particular vulnerable, due to the large porous wood compartment. Materials and Methods.This study tests the toxicity of TiO 2 -nanoparticles on trees with the short-term willow tree transpiration test. TiO2-particles with 25 and 100 nm diameter were suspended in distilled water at concentrations of 0, 1, 10 and 100 mg/L (first test) and 0, 10, 20 and 50 mg/L (second test). Effects on transpiration, growth and water use efficiency of exposed willow cuttings were monitored. The concentration of nanoparticles was measured by spectrophotometry.Results. None of the measured effect parameters (growth, transpiration and water use efficiency) showed any significant change during the test. Particles were rapidly lost from solution, probably due to sedimentation as a result of aggregation, and also due to adsorption to roots. The loss of nanoparticles from solution was faster for particles with larger diameter and in the presence of trees.Discussion. Willow trees were not sensitive to short-term exposure to TiO2-nanoparticles. Similar results were obtained for other plant species. Effects of nanoparticles were observed for zinc and zinc oxide particles, but these effects were probably due to heavy metal toxicity and not nano-size specific. 2Conclusions. In summary, we came to the conclusion that woody species are not in particular vulnerable to nanosized TiO2-particles in the conditions, concentrations and time periods used in this study. Recommendations and Perspectives.The preliminary results of this study should be confirmed with other types of MNP, other plant species, experiments in soil and experiments combining longer duration and low exposure concentrations, before a final conclusion in this issue can be made.

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Phytotoxicity of Cyanide to Weeping Willow Trees

Cited by 41 publications

References 10 publications

Effect of Temperature on the Uptake and Metabolism of Cyanide by Weeping Willows

Effect of Temperature on the Uptake and Metabolism of Cyanide by Weeping Willows

Uptake, assimilation and toxicity of cyanogenic compounds in plants: facts and fiction

Insignificant acute toxicity of TiO2 nanoparticles to willow trees

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