Dose-dependent effects of multi-walled carbon nanotube on seed germination, growth, photosythetic pigments and lipid peroxidation of six plant species

The multi- walled carbon nanotubes (MWCNTs) are one of the most widely used engineered nanoparticles and are expected to enter natural ecosystems. More studies on plants, as a part of food chain, are needed to understand profoundly the toxicity and health risks of CNMs as ecotoxicological stressors. In this study, The effects of multi- walled carbon nanotubes (MWCNTs) with a length 30 nm on seed germination and growth of six plant species () were evaluated in petri dish (direct exposure) and in soil in a greenhouse experiment (soil exposure). Data demonstrate that under both culture conditions, low or mild concentrations MWCNT either stimulated or had no effect on seed germination, root growth and vegetative biomass while high concentrations had an inhibitory effect. However, results showed that the impacts of MWCNT on plant growth in soil were partially consistent with those observed in pure culture. Based on data among above six species, lettuce and canola were the most susceptible and the most tolerant species to MWCNT toxicity. In all species root growth was more susceptible to MWCNT toxicity than seed germination or shoot growth. The high concentrations of MWCNT caused significant reductions in fresh and dry weight of arial parts and root and chlorophyll and carotenoids contents of all species which also coincided with further accumulation of malondealdehyde (MDA). These findings suggest that decreasing growth might be the result of an MWCNT-induced oxidative stress and disturbtion of photosynthesis systems

کلیدواژه ها:

Chlorophyll ، Growth ، Malondealdehyde ، MWCNT ، Seed germination