Emission spectra of QDs in H₂O over 7 days.

<p>Emission spectra of QDs in H₂O over 7 days.</p

Schematic of a putative mechanism through which CdTe-QDs are processed by plant cells.

<p>Schematic of a putative mechanism through which CdTe-QDs are processed by plant cells.</p

Confocal imaging of CdTe-QDs distribution in wheat root cells.

<p>CdTe-QDs are indicated by fluorescence imaging (g, h, i, m, n, o, s), DIC images demonstrate cell integrity (a, b, c, d, e, f, j, k, l, p, q, r, t). Regions highlighted in red in panel e are shown in panels s, t, and u. Pictures of the bottom right corner in figure j, k, l, p, q, r is the merge figures of g and j, h and k, i and l, m and p, n and q, o and r separately. Scale bars = 20 µm.</p

Cell wall reconstruction and DNA damage repair play a key role in the improved salt tolerance effects of He-Ne laser irradiation in tall fescue seedlings

<p>The improved salt tolerance effects of He–Ne laser were further studied through the estimation of ROS levels, cell viability, DNA damage phenomena, physicochemical properties, and monosaccharide compositions of cell wall polysaccharides in tall fescue seedlings. Salt stress produced deleterious effects on seedlings growth and development. ROS levels and genomic DNA damage were markedly increased compared with controls. Physicochemical activities and monosaccharide proportions of cell wall polysaccharide were also pronouncedly altered. He–Ne laser irradiation improved plant growth retardation via increasing cell viability and reverting physicochemical parameters. According to the results of Fourier transform infrared (FTIR) scanning spectra and DNA apopladder analysis, He–Ne laser was showed to efficiently ameliorate cell wall polysaccharide damage and DNA fragmentation phenomena. The treatment with DNA synthesis inhibitor further demonstrated that DNA damage repair was correlated with the improvement effects of the laser. Therefore, our data illustrated that He–Ne laser irradiation resulted in cell wall reconstruction and genomic DNA injury repair <i>in vivo</i> in salt-stressed seedlings, then enhanced salt tolerance probably via interactions between plant cell wall and related resistance gene expression pattern.</p> <p>A proposed model regarding the improved salt resistance of He–Ne laser irradiation through modulating plant cell wall reconstruction and genomic DNA damage repair capacity.</p

Schematic of the antioxidative defense system and Cd degradation mechanism in plants.

<p>Schematic of the antioxidative defense system and Cd degradation mechanism in plants.</p

Contents of H₂O₂ and O₂⁻ in the root and shoot of 5 day old seedlings following different treatments. Data are means±SD (n = 3).

<p>Means with the same letter are not significantly different at Tukey’s test (p≤0.05).</p

Light/dark cycles and treatment regimens with UV-B and CdTe-QDs.

<p>Light/dark cycles and treatment regimens with UV-B and CdTe-QDs.</p

Effects of different CdTe-QDs concentrations on 5-day-old wheat seedlings.

<p>CK, control group; C, treatment groups with different concentrations of CdTe-QDs (C1, 25 mg/L; C2, 50 mg/L; C3, 100 mg/L; C4, 200 mg/L; C5, 400 mg/L). Data are means±SD (n = 3). Means with the same letter are not significantly different at Tukey’s test (p≤0.05).</p

DNA laddering in wheat tissues.

<p>Electrophoresis gels of DNA extracted from wheat with different treatments. CK: control group; B: enhanced UV-B radiation; C: CdTe-QDs treatment; B+C: combined UV-B and CdTe-QDs treatment.</p

Average fluorescence intensity of QDs in 50 cells after different treatment durations.

<p>C, CdTe-QDs treatment alone; B+C, combined enhanced UV-B and CdTe-QDs treatment. Values are means±SD (n = 3). Means with the same letter are not significantly different at Tukey’s test (p≤0.05).</p