Growth of Arabidopsis seedlings in the presence of gold.

<p>(A) Appearance and (B) root length of ten-day-old seedlings grown on agar plates containing a range of gold concentrations, as K(AuCl₄). (C) Root length of ten-day-old seedlings grown on agar plates containing a range of gold concentrations, as AuCl₃. Results are the mean from 30 biological replicates ± SD. * = significantly different from no gold, at day 8 (<i>p</i><0.001). Transmission electron micrographs showing gold nanoparticles in tissue of plants grown on agar plates containing 100 mg/L gold. (D) Leaf mesophyll and (E) leaf vascular tissue; (F) root cortex and (G) root vascular tissue. NP, nanoparticle; Cy, cytoplasm; Cw, cell wall, X, xylem; Ch, chloroplast.