Microscopic response of <i>Vitis vinifera</i> varieties to ozone treatment observed by SEM.

<p>Micrographs of abaxial leaf surfaces observed by SEM in <i>Vitis vinifera</i>: Aleatico (A) and Trebbiano giallo (B) treated with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) + 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 days. Arrows show deformed swelling areas. The magnification of these areas in Aleatico (C) revealed skin cracks on the epidermis (arrowhead). Bar marker is 500 μm (A-B) and 1 μm (C).</p

Diurnal time courses of photosynthetic pigments in <i>Vitis vinifera</i> varieties exposed or not to ozone treatment.

<p>Diurnal time courses of chlorophyll <i>a</i>/<i>b</i> ratio (chl <i>a</i>/<i>b</i>, A-B), total chlorophyll (tot chl, B-C), β-carotene (D-E) and α-tocopherol (F-G) in <i>Vitis vinifera</i> leaves (Aleatico, left, and Trebbiano giallo, right) after a fumigation with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) and 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 days. Data are shown as mean ± standard deviation. The measurements were taken from untreated (open circle) and treated (closed circle) plants at the end of exposure. For each parameter, different letters indicate significant differences (<i>P</i>≤0.05). In the boxes, results of repeated measurements ANOVA are reported. Asterisks show the significance of factors (ozone and time of day) and their interaction for: *** = <i>P</i>≤0.001, ** = <i>P</i>≤0.01, * = <i>P</i>≤0.05).</p

Diurnal time courses of chlorophyll <i>a</i> fluorescence parameters in <i>Vitis vinifera</i> varieties exposed or not to ozone treatment.

<p>Diurnal time courses of variable and maximal fluorescence ratio (F_v/F_m, A-B), actual quantum yield of PSII (Φ_PSII, C-D) and fraction of light absorbed by PSII antenna which are thermally dissipated (%D, E-F) in <i>Vitis vinifera</i> leaves Aleatico, left, and Trebbiano giallo, right) after a fumigation with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) and 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 days. Data are shown as mean ± standard deviation. The measurements were taken from untreated (open circle) and treated (closed circle) plants at the end of exposure. For each parameter, different letters indicate significant differences (<i>P</i>≤0.05). In the boxes, results of repeated measurements ANOVA are reported. Asterisks show the significance of factors (ozone and time of day) and their interaction for: *** = <i>P</i>≤0.001, ** = <i>P</i>≤0.01, * = <i>P</i>≤0.05).</p

Diurnal time courses of accessory pigments in <i>Vitis vinifera</i> varieties exposed or not to ozone treatment.

<p>Diurnal time courses of lutein (A-B), violaxanthin (C-D) content and de-epoxidation index (DEPS, E-F) in <i>Vitis vinifera</i> leaves Aleatico, left, and Trebbiano giallo, right) after a fumigation with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) and 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 days. Data are shown as mean ± standard deviation. The measurements were taken from untreated (open circle) and treated (closed circle) plants at the end of exposure. For each parameter, different letters indicate significant differences (<i>P</i>≤0.05). In the boxes, results of repeated measurements ANOVA are reported. Asterisks show the significance of factors (ozone and time of day) and their interaction for: *** = <i>P</i>≤0.001, ** = <i>P</i>≤0.01, * = <i>P</i>≤0.05).</p

Microscopic response of <i>Vitis vinifera</i> varieties to ozone treatment observed by transmission electron microscopy.

<p>Micrographs of palisade cell chloroplasts in <i>Vitis vinifera</i> plants observed by transmission electron microscopy. (A) Aleatico and (B) Trebbiano giallo controls: presence of elongated chloroplasts and regular thylakoid system. (C) Aleatico and (D) Trebbiano giallo treated with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) and 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 days: increase in the size of the plastoglobuli. (E) Aleatico treated: degradation of thylakoid system. Bars represent 1 μm.</p

Microscopic response of <i>Vitis vinifera</i> cv. Aleatico to ozone treatment observed by light microscopy.

<p>Leaf semi-thin cross sections in <i>Vitis vinifera</i> cv. Aleatico (10 μm thick) observed by light microscopy. Plants were maintained in filtered air (A) or treated with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) + 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 consecutive days (B): modifications of mesophyll anatomy and irregular increase in leaf thickness.</p

Weekly profiles of light curve-parameters derived in <i>Vitis vinifera</i> varieties exposed or not to ozone treatment.

<p>Weekly profiles of light saturation point (LSP, A-B), light compensation point (LCP, C-D) and net photosynthetic rate at light saturation point (A_max, E-F) in <i>Vitis vinifera</i> leaves (Aleatico, left, and Trebbiano giallo, right) after a fumigation with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) and 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 days. Data are shown as mean ± standard deviation. The measurements were taken from untreated (open circle) and treated (closed circle) plants. For each parameter, different letters indicate significant differences (<i>P</i>≤0.05). In the boxes, results of repeated measurements ANOVA are reported. Asterisks show the significance of factors (ozone and time of day) and their interaction for: *** = <i>P</i>≤0.001, * = <i>P</i>≤0.05, ns = <i>P</i>>0.05).</p

Weekly profiles of A/C_i curve-parameters in <i>Vitis vinifera</i> varieties exposed or not to ozone treatment.

<p>Profiles of maximum rate of Rubisco activity (V_cmax, A-B), light-saturated rate of electron transport (J_max, C-D), CO₂ saturation point (CSP, E-F) and CO₂ compensation point (CCP, G-H) in <i>Vitis vinifera</i> leaves (Aleatico, left, and Trebbiano giallo, right) after a fumigation with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) and 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 days. Data are shown as mean ± standard deviation. The measurements were taken from untreated (open circle) and treated (closed circle) plants. For each parameter, different letters indicate significant differences (<i>P</i>≤0.05). In the boxes, results of repeated measurements ANOVA are reported. Asterisks show the significance of factors (ozone and time of day) and their interaction for: *** = <i>P</i>≤0.001, ** = <i>P</i>≤0.01, * = <i>P</i>≤0.05).</p

Microscopic response of <i>Vitis vinifera</i> cv. Aleatico to ozone treatment observed by light and transmission electron microscopy.

<p>Micrographs of ultra-thin sections observed by light microscopy (70 nm thick; A-B) and details of palisade layer observed by transmission electron microscopy in <i>Vitis vinifera</i> cv. Aleatico. Plants were maintained in filtered air (A; C) or treated with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) + 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 days (B; D).Bar marker is 10 μm (A-B), 20 μm (C) and 30 μm (D).</p

Diurnal time courses of gas exchange parameters in <i>Vitis vinifera</i> varieties exposed or not to ozone treatment.

<p>Diurnal time courses of assimilation rate (A, A-B), stomatal conductance to water vapour (G_w, C-D) and intercellular CO₂ concentration (C_i, E-F) in <i>Vitis vinifera</i> leaves (Aleatico, left, and Trebbiano giallo, right) after a fumigation with 80 ppb of O₃ for 5 h day^-1 (8:00–13:00 h) and 40 ppb of O₃ for 5 h day^-1 (13:00–18:00 h) for 28 days. Data are shown as mean ± standard deviation. The measurements were taken from untreated (open circle) and treated (closed circle) plants at the end of exposure. For each parameter, different letters indicate significant differences (<i>P</i>≤0.05). In the boxes, results of repeated measurements ANOVA are reported. Asterisks show the significance of factors (ozone and time of day) and their interaction for: *** = <i>P</i>≤0.001, ** = <i>P</i>≤0.01, * = <i>P</i>≤0.05.</p