Efeito de nanopartículas de prata (AgNPs) na germinação e crescimento de raízes de maxixe (Cucumis anguria L.)

Abstract

Nanoparticles have been released into the environment by products used in industry, in general. The releasing of these compounds can cause damage to the living beings, like plants and aquatic animals, as well as cause alterations in food chain. This work evaluated the effects of silver nanoparticles (AgNPs) in different concentrations: 12,5; 25; 50 and 100 ppm (parts per million) on germination, growth and structure of maxixe seeds (Cucumis anguria L.), aiming to evaluate the effects on treatments under different concentrations of silver nanoparticles in their development. It was observed in the 25 ppm treatment a significant root growth compared to the negative control (nitric acid). On the other hand, roots submitted to the 50 ppm treatment presented the smallest growth among the tests. This study showed that there is no direct correlation between nanoparticles concentration and inhibition of root’s growth. Scanning electron microcopy (SEM) analysis showed that the treated seeds with silver nanoparticles (AgNPs) that germinated later (after the third day), presented atrophy of their root hair. EDX showed high detection of Ag in the seed treated with 100 ppm, what indicates an accumulation of nanoparticles on the surface of the seed. In the other treatments with nanoparticles, there weren’t a significant detection of Ag on the surface of the seed, what shows that these NPs were absorved e translocated inside the plant or they weren’t absorved. Seeds treated with the concentrations of 50 and 100 ppm presented negative effects in relation to the control: inhibition of root growth, low rate of germination and atrophy of root hair, showing that AgNPs can be toxic to maxixe species (Cucumis anguria L.).