with respect to controls, respectively. The EC50 (see the downward
arrows) in terms of stem length and average surface area per leaf was 19
and 21 mg/L, respectively. The plant transpiration was also decreased
significantlywith increase in Zn2+ concentration (Fig. S3d). After exposure
to 50 mg/L of Zn2+ for 20 days, plants used 54% less solution compared to
controls (or EC50=15 mg/L, see the downward arrow). Results in Table 1
also implied the possible transport of Zn2+ ions fromthe mediumto stems
and leaves via rootswhen plantswere exposed to nZnO. The trace amount
of Zn2+ present in controlled roots, stems, and leaves was probably
derived from the FP medium that contained a small account of Zn2+
(e.g., 0.77 μM). Sagardoy et al. (2009)