The widespread utilization of nano-enabled products in agriculture (e.g., nano-fertilizers and nano-pesticides) would inevitably expedite the entry of engineered nanoparticles (ENPs) into plants. However, mechanic studies on how ENPs are internalized by plant leaves have been limited. This work aimed to investigate the contribution of stomata to the sorption of silver nanoparticles (AgNPs) by Arabidopsis thaliana using batch experiments. Ecotypes (Landsberg erecta [Ler] and Col7) and the abscisic acid (ABA) defective mutants ost1-2 and scord7 were used as plant materials. In comparison with the ABA-free control, stomatal apertures in ecotypes Ler and Col-7 remarkably decreased, but remained unchanged in ABA-deficient mutants ost1-2 and scord7 (p &lt; 0.05), after 10-µM ABA treatment for 1 h. The sorption kinetics showed that the maximum sorbed amounts were reached by 60 min of equilibration time. The sorbed amount of AgNPs by ecotypes Ler and Col-7 treated with 10 µM ABA were much lower than that in the ABA-free control, mainly due to the ABA-induced stomatal closure. There was no significant difference in the sorption of AgNPs in the mutants ost1-2 and scord7 with and without ABA. The subcellular distribution of internalized AgNPs in Arabidopsis thaliana leaves was probed using ultra-high-resolution transmission electron microscopy. Our results shed light to the important role of stomata in the internationalization of ENPs in plants and may have broad implications to not only stomatal biology but also management strategies for decreasing the ENPs contamination.

Role of stomata in foliar sorption of silver nanoparticles by Arabidopsis thaliana

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.