Nanoparticles migration to the apex of a trichome. A) Phase contrast image of a trichome. B) Detail of the region squared in (A), showing the presence of nanoparticle aggregates as optically dense material, in the cell interior (*) as well as in the outer face of the epidermal cell wall (arrows). C) TEM image of a region equivalent to the one indicated by (*) in (B). Nanoparticles appear as aggregates associated to intracellular structures. Bar in A and B = 50 μm; C = 2 μm;.