GUS accumulation in roots of <i>ACS1</i>::<i>GUS</i> reporter plants colonized by <i>P. indica</i>.

<p><i>Arabidopsis</i> line <i>ACS1</i>::<i>GUS</i> was harvested at 7 dai and, after GUS and WGA-AF 488 staining, analyzed cytologically. (<b>A</b>, <b>B</b>) <i>P. indica</i> colonization at the base of lateral roots (arrows) or primordia (asterisks) of line <i>ACS1</i>::<i>GUS</i> was associated with enhanced GUS accumulation. <i>P. indica</i> (arrowsheads in A) was visualized by staining with WGA-AF 488. (<b>C</b>) In mock-treated <i>ACS1</i>::<i>GUS</i>, GUS staining was weakly detectable e.g. at the lateral root base. Bars = 60 µm.</p

Colonization of ethylene synthesis and signaling mutants by <i>P. indica</i>.

<p>(<b>A</b>) Three-week-old plants were inoculated with <i>P. indica</i> and fungal biomass was determined in <i>ein2-1</i>, <i>etr1-3, eto1-1, ctr1-1</i>, and <i>35S</i>::<i>ERF1</i> by qRT-PCR at 3 and 14 dai. (<b>B</b>) Three-week-old <i>35S::ERF1</i> plants were injured with foreceps and inoculated with <i>P. indica</i> at 1 day after wounding. Fungal biomass was determined by qRT-PCR at 3 and 7 dai. All values were related to Col-0 (set to one). The data are based on at least three independent experiments. Students <i>t</i>-test indicated significant difference in <i>P. indica</i>-colonization (* P<0.05, ** P<0.001).</p

Colonization of barley and <i>Arabidopsis</i> by <i>P. indica</i> in response to ACC and MCP.

<p>(<b>A</b>) Two-day-old barley seedlings or (<b>B</b>) two-week-old <i>Arabidopsis</i> seedlings were inoculated with <i>P. indica</i> and subsequently treated with 500 ppt 1-methylcyclopropene (MCP) as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035502#s4" target="_blank">Materials and Methods</a>. Barley was also treated with 100 µM 1-aminocyclopropane-1-carboxylic acid (ACC). MCP inhibited <i>P. indica</i> colonization at 3 or 7 dai in <i>Arabidopsis</i> or barley, respectively. The values are normalized to colonization in mock-treated roots (set to one). The data are based on three independent biological experiments. Student's <i>t</i>-test indicates a significant difference in <i>P. indica</i>-colonization of MCP-treated roots (* P<0.05).</p

List of barley genes differentially regulated by <i>P. indica</i> and involved in ethylene synthesis or signaling.

1<p>Gene expression data was published in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035502#pone.0035502-Schfer2" target="_blank">[27]</a>.</p

Suppression of chitin-induced oxidative burst by <i>P. indica</i>.

<p>Chitin (1 µM <i>N</i>-acetylchitooctaose) was applied to barley root segments of seedlings harvested at 3 days after <i>P. indica</i>- or <i>Rhizoctonia solani</i> inoculation or mock-treatment, respectively. Values are given as relative light units (RLU) over time as means with standard errors of two biological experiments with three independent measurements per treatment and experiment. GP, barley cv. Golden Promise.</p

ACC content in barley roots during <i>P. indica</i> colonization.

<p>Free (<b>A</b>) and malonylated (<b>B</b>) 1-aminocyclopropane-1-carboxylic acid (ACC) contents were determined in <i>P. indica</i> and mock-treated roots at 1, 3, and 7 days after treatments. At 1 dai, the complete roots were harvested and forwarded to ACC measurements. At 3 and 7 dai, the upper two centimeters (basal part) and the remaining part of the roots (apical part) were analyzed separately. Absolute values are given in nmol • g FW⁻¹ for mock-treated and <i>P. indica</i>-colonized roots. (<b>A</b>) Free ACC levels were significantly enhanced at 3 and 7 dai in the apical zone and 7 dai in the basal part as indicated by Students <i>t</i>-test (* P<0.05, ** P<0.01, *** P<0.001). (<b>B</b>) Malonylated ACC was not significantly altered during <i>P. indica</i> colonization at any timepoint or in any tissue. Data show the mean content of four biological experiments (with at least two technical repetitions per experiment) and bars indicate standard errors.</p

GUS accumulation in roots of <i>ACS1</i>::<i>GUS</i> and <i>ACS8</i>::<i>GUS</i> reporter plants colonized by <i>P. indica</i>.

<p><i>Arabidopsis</i> lines <i>ACS1</i>::<i>GUS</i> and <i>ACS8</i>::<i>GUS</i> were harvested at 7 dai and, after GUS and WGA-AF 488 staining, analyzed cytologically. GUS staining was more pronounced in root tip regions of colonized roots as compared to mock-treated roots (upper images). At 7 dai, <i>P. indica</i>-colonized roots of both lines showed a significant increase of dark blue tips and a significant reduction in pale blue tips as compared to mock-treated roots. GUS staining did not colocalize with colonization sites of <i>P. indica</i> or extracellular fungal growth. The data base on at least two biological experiments. Asterisks indicate significant differences between control and <i>P. indica</i>-colonized roots according to Students <i>t</i>-test (* P<0.05, ** P<0.001).</p