<i>A</i>. <i>thaliana</i> seed permeability assay.

<p>Seeds were incubated for 24 h in tetrazolium red at 28°C and formazan production assayed by measuring absorbance of the incubation solution at 492 nm. For plasma treated (purple bar), the air plasma was used and seeds were incubated with tetrazolium immediately following treatment. Control (blue bar) were treated similarly but without activating the plasma. Water (white bar) treatment omitted the tetrazolium. Bars show mean of 4 assays and the error bars are 0.05 (For data see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195512#pone.0195512.s001" target="_blank">S1 Fig</a>).</p

Class III peroxidases activity and reactive oxygen species detection.

<p>Class III peroxidases activity was detected seeds by using guaiacol as substrate (A and B). Superoxide ion O₂^.- was observed y with NBT (C and D). Control seeds (A and C) and seeds treated with air plasma (B and D). The intensity of the coloration appeared to be identical at the same level of germination for both cases (control or plasma treated seeds). Each scale bar corresponds to 100 μm.</p

Physico-chemical parameters of waters.

<p>Electric and chemical parameters of deionized water (H₂Od), tap water (Water_tap) and plasma-activated deionized water (PAW_H₂Od) and tap water (PAW_tap). The conductivity is expressed in relative value differences: Δσ/σ. The measurements of concentrations, pH and conductivity are made 3 times independently.</p

Different plasma devices.

<p>A. Schematic view of the helium plasma jet device on the right side and picture during the generation of plasma activated water inside a glass beaker using the helium plasma jet and a magnetic stirrer. B. Schematic view of the floating electrode-dielectric barrier discharges (FE-DBD) in air showing the powered electrode covered by glass (in blue colour) with seeds in ambient air plasma above the lamella (right side) and picture displaying the air plasma over the glass lamella.</p

Scanning electron microscopy (SEM) images of <i>A</i>. <i>thaliana</i> seeds.

<p>(A, C, E) are the control while (B, D, F) are the air plasma treated. Scale bars: 100 μm A, B; 50 μm C, D; 10 μm E, F.</p

Effects of plasma-activated tap water (PAW_tap) on <i>A</i>. <i>thaliana</i> growth.

<p>Photos after 28 days of development watered by tap water (A) and PAW_tap (B). Diameter of the rosette (C); <i>A</i>. <i>thaliana</i> seedling leaf number (D); area of the leaves (E), and total number of flowering plants (F). Wilcoxon test was used to test the significance between the means with p-value indicated as: · < 0.1; *<0.05; **<0.005; ***<0.002 (For data see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195512#pone.0195512.s001" target="_blank">S1 Fig</a>).</p