Low levels of TiO2-nanoparticles interact antagonistically with Al and Pb alleviating their toxicity
2021
Mariz-Ponte, Nuno | Dias, Celeste M. | Silva, Artur M.S. | Santos, Conceição | Silva, Sónia
The contamination and bioavailability of deleterious metals in arable soils significantly limits crop development and yield. Aiming at mitigating Pb- and Al-induced phytotoxicity, this work explores the use of P25 titanium dioxide nanoparticles (nTiO₂) in soil amendments. For that, Lactuca sativa L. plants were germinated and grown in the presence of 10 ppm Pb or 50 ppm Al, combined or not with 5 ppm nTiO₂. Growth parameters, as well as endpoints of the redox state [cell relative membrane permeability (RMP), thiobarbituric acid reactive substances content, total phenolic content and photosynthesis (sugars and pigments levels, chlorophyll a fluorescence and gas exchange), were evaluated. Concerning Al, nTiO₂ treatment alleviated the impairments induced in germination rate, seedling length, water content, RMP, stomatal conductance (gₛ), intercellular CO₂ (Cᵢ), and net CO₂ assimilation rate (PN). It increased anthocyanins contents and effective efficiency of photosystem II (ΦPSII). In Pb-exposed plants, nTiO₂ amendment mitigated the effects in RMP, PN, gₛ, and Cᵢ. It also increased the pigment contents and the transpiration rate (E) comparatively to the control without nTiO₂. These results clearly highlight the high potential of low doses of nTiO₂ in alleviating metal phytotoxicity, particularly the one of Pb. Additionally, further research should explore the use of these nanoparticles in agricultural soil amendments.
显示更多 [+] 显示较少 [-]