Cd and Zn tolerance of yeast cells expressing <i>SaMT2</i>.

<p>The <i>Saccharomyces cerevisiae</i> BY4741, <i>Δycf1</i> and <i>Δzrc1</i> yeast cells harboring pDR195 (vector control) or pDR195-<i>SaMT2</i> were grown in liquid SD selective medium. Cultures were adjusted to OD_600nm of 0.1 and serially 10-fold diluted in water. 10 µl aliquots of each dilution were spotted either on SD selective plates or on plates with 30 µM CdCl₂ or 5 mM ZnSO₄. After 3 days of incubation at 30°C, plates were photographed. CK represents the control group.</p

Metal tolerance analysis of transgenic tobacco plants over-expressing <i>SaMT2</i>.

<p>The figure shows the effect of 200 µM ZnSO₄ or 100 µM CdCl₂ on the growth of WT and transgenic plants on B5 medium. CK represents the control group.</p

Sequence alignment and phylogenic analysis of <i>SaMT2</i> with other MTs.

<p>(A) The deduced amino acid sequences encoded by <i>SaMT2</i> were aligned with MTs from <i>Arabidopsis thaliana</i>, <i>Noccaea caerulescens</i> and <i>Solanum nigrum</i>. The cysteine-rich domains are boxed. (B) The phylogenic tree of <i>SaMT2</i> and MTs from Arabidopsis and rice.</p

Cd and Zn concentration in <i>Δycf1</i> and <i>Δzrc1</i> yeast cells expressing <i>SaMT2</i>.

<p>The yeast transformants containing pDR195 or pDR195-<i>SaMT2</i> were grown in liquid SD selective medium with 30 µM CdCl₂ and 100 µM ZnSO₄ for <i>Δycf1 and </i><i>Δzrc1</i>, respectively. Cells were incubated at 30°C for 48 h and metal contents were measured by ICP-MS. Results are averages (±S.E.) from three independent experiments done with four different colonies. The ‘*’ symbol indicates the mean values were significantly different at p<0.05 (Tukey’s test).</p

Cd and Zn concentrations in wild type amd transgenic tobacco lines overexpressing <i>SaMT2</i>.

<p>Three independent <i>SaMT2</i> over-expressing lines and wild-type tobacco were grown in nutrient solution containing 50 µM CdCl₂, 100 µM ZnSO₄ for 1 week. A: Cd concentration in roots, B: Cd concentrantion in shoots, C: Zn concentration in roots, D: Zn concentration in shoots. Results are means ± S.E. (n = 3). Different letter indicate the mean values were significantly different from WT tobacco determined by Tukey’s test (p<0.05).</p

The expression level of <i>SaMT2</i> in <i>Sedum alfredii</i>.

<p>The transcript level of <i>SaMT2</i> induced by Cd and Zn treatments. The different letters above the columns indicate the significant difference between the treatments (p<0.05, Tukey’s test). CK represents the control group.</p

Relative root growth of transgenic tobacco plants.

<p>The relative root growth of WT and transgenic tobacco plants under Cd (A) and Zn (B) treatments. Different letters above the columns indicate a significant difference among different plant lines (p<0.05, Tukey’s test).</p

Elemental concentrations of rice grains, hull, brown rice, bran, and polished rice.

<p>All concentrations are expressed as mg kg⁻¹ DW. Data points and error bars represent means and SEs of four replicates.</p

µ-XRF elemental maps of early stage rice seedlings after seed germination for 48

<p> <b>h.</b> The orientation of the individual µ-XRF elemental maps and the color-merged image (upper right) is the same as that of the green rectangle around a portion of the labeled image of the germinating seed. Refer to the legend for <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057360#pone-0057360-g004" target="_blank">Figure 4</a> for additional details.</p

Typical synchrotron radiation X-ray fluorescence (SR-XRF) microprobe spectrum in an embryo localized scanning point of rice grain.

<p>Typical synchrotron radiation X-ray fluorescence (SR-XRF) microprobe spectrum in an embryo localized scanning point of rice grain.</p