Effect of hemibiotroph <i>P</i>. <i>infestans</i> or necrotroph <i>B</i>. <i>cinerea</i> inoculation on free SA level and ethylene production in potato.

<p>(A, B) free SA content and (C, D) ethylene production in potato leaves of cv. Bzura and cv. Bintje. (*) significantly different from mock-inoculated (control) potato leaves, P<0.05. Values represent mean ± SD of at least three independent experiments.</p

Effect of hemibiotroph (<i>P</i>. <i>infestans)</i> or necrotroph (<i>B</i>. <i>cinerea</i>) inoculation on S-nitrosothiols in potato.

<p>Total contents of S-nitrosothiols (SNOs) in leaves of potato (A-C) cv. Bzura and (G-I) cv. Bintje inoculated with <i>P</i>. <i>infestans</i> or <i>B</i>. <i>cinerea</i> at 48 hpi. Detection of SNOs in potato leaves was performed by immunofluorescence histochemistry using Alexa Fluor 405 Hg–Link reagent phenylmercury; blue fluorescence is attributable to SNOs. Images of leaf cross section show general phenomena representative of three individual experiments. Representative images illustrating the immunodetection of endogenous GSNO in (D) control leaves of potato cv. Bzura and in leaves inoculated with (E) <i>P</i>. <i>infestans</i> or (F) <i>B</i>. <i>cinerea</i>. (J) Total SNO content in leaves of potato determined by chemiluminescence assay using Sievers Nitric Oxide Analyzer NOA 280i; (*) significantly different from mock-inoculated potato leaves, P<0.05. Values represent the mean ± SD of at least three independent experiments. (K) Potato leaf cross section viewed under white light: 1 –palisade mesophyll, PM; 2 –spongy mesophyll, SM; 3 –parenchyma, P; 4 –xylem, Xm; 5 –epidermal cells, Ep. Bars indicate 200 μm (A-C, G-I, K) and 100 μm (D-F).</p

Primers used in real-time PCR reaction.

<p>Primers used in real-time PCR reaction.</p

Effect of hemibiotroph <i>P</i>. <i>infestans</i> or necrotroph <i>B</i>. <i>cinerea</i> inoculation on <i>PR</i> gene expression.

<p>(A, B) <i>PR-1</i>, (C, D) <i>PR-2</i> and (E, F) <i>PR-3</i> gene expression in potato leaves of cv. Bzura and cv. Bintje. (*) significantly different from mock-inoculated (control) potato leaves, P<0.05. Values represent mean ± SD of at least three independent experiments.</p

Effect of hemibiotroph <i>P</i>. <i>infestans</i> or necrotroph <i>B</i>. <i>cinerea</i> inoculation on hydrogen peroxide production and germin-like oxidase in potato.

<p>(A, B) Hydrogen peroxide accumulation and (C, D) germin-like oxidase activity in potato leaves of cv. Bzura and cv. Bintje. (*) significantly different from mock-inoculated (control) potato leaves, P<0.05. Values represent mean ± SD of at least three independent experiments.</p

Effect of <i>P</i>. <i>infestans</i> or <i>B</i>. <i>cinerea</i> inoculation on disease establishment in susceptible and resistant potato cultivars.

<p>The percentage of leaf area infected by the hemibiotroph or necrotroph was measured 7 days after appropriate pathogen challenge inoculation. Values are means from 30 leaves (10 leaves from each of three independent experiments).</p

Effect of hemibiotroph <i>P</i>. <i>infestans</i> or necrotroph <i>B</i>. <i>cinerea</i> inoculation on superoxide production and NADPH oxidase activity.

<p>Superoxide anion generation in potato challenged with <i>P</i>. <i>infestans</i> or <i>B</i>. <i>cinerea</i>, respectively, in (A) cv. Bzura and (B) Bintje. NADPH oxidase activity in potato leaves after pathogen inoculation in (C) cv. Bzura and (D) Bintje. (*) significantly different from mock-inoculated (control) potato leaves, P<0.05. Values represent the mean ± SD of at least three independent experiments.</p

Nitric oxide production in potato-pathogen interaction.

<p>Electrochemical detection of NO emission from potato leaves challenged with the hemibiotroph <i>P</i>. <i>infestans</i> or the necrotroph <i>B</i>. <i>cinerea</i> in (A) cv. Bzura and (B) Bintje. Values represent the mean ± SD of three independent experiments.</p

Peroxynitrite formation and tyrosine nitration in potato leaves challenged with <i>P</i>. <i>infestans</i> or <i>B</i>. <i>cinerea</i>.

<p>Peroxynitrite content in potato challenged with <i>P</i>. <i>infestans</i> or <i>B</i>. <i>cinerea</i>, respectively, in (A) cv. Bzura and (B) Bintje. (*) significantly different from mock-inoculated (control) potato leaves, P<0.05. Values represent the mean ± SD of at least three independent experiments. (C-F) Representative images illustrating microscopic localization of protein 3-nitrotyrosine in leaf cross-sections of both potato genotypes challenge inoculated with the pathogens at 24 hpi. Bars indicate 200 μm (C-F). (G) Signal intensities were quantified using Multi Guide V2.2 software (Fujifilm) and expressed in arbitrary units.</p

TUNEL test illustrating programmed DNA fragmentation in potato leaves inoculated with the hemibiotroph <i>P</i>. <i>infestans</i> or with the necrotroph <i>B</i>. <i>cinerea</i>.

<p>(A) TUNEL fluorescein-positive reaction (green nuclei in fluorescence microscopy) detected in the avr <i>P</i>. <i>infestans</i>–Bzura interaction at 24 hpi; (B) TUNEL fluorescein–negative reaction in <i>P</i>. <i>infestans</i> susceptible potato cv. Bintje inoculated with the hemibiotroph; TUNEL fluorescein-positive reaction in (C) the Bzura–<i>B</i>. <i>cinerea</i> and (D) the Bintje–<i>B</i>. <i>cinerea</i> interactions at 24 hpi. Bars indicate 15 μm (A-D).</p