Choice and no choice tests with the green peach aphid (<i>Myzus persicae</i>).

<p>(A) Choice bioassays performed on pairs of plant genotypes where a single <i>M. persicae</i> alate female was released in each cage containing the most comparable pair of genotypes. The initial nymph deposition preference was determined within 2 days of aphid release. Bar graphs represent the actual numbers of alates. One-tailed binomial tests were used to determine significance (<i>P</i><0.05). (B) Population increase of aphids (fecundity) upon the release of a newly deposited nymph on a single plant of indicated genotype during 15 days of reproduction. The graphs indicate the mean numbers of aphids per plant±SE. Each of the above-described tests was performed on ∼30 individual plants per genotype.</p

Function of JAs and C₆-aldehydes in plant protection against necrotrophic fungus, <i>Botrytis cinerea.</i>

<p>Lesion development was monitored and compared between leaves isolated from (A) <i>HPL-OE</i> vs. Col, (B) <i>aos</i>-<i>hpl</i> vs. <i>aos-HPL-OE</i>, (C) <i>gl-1</i> vs. <i>aos-hpl</i>, at 48, 72 or 96 hours post inoculation (hpi) with <i>B. cinerea</i> conidia. Each bar graph represents average lesion diameter±SD of 24 inoculated leaves. All leaves lacking jasmonates (<i>aos-hpl</i>, <i>aos-HPL-OE)</i> show larger lesions as compared to those with a functional AOS (Col, <i>HPL-OE</i>, <i>gl-1</i>). The lesion sizes were not affected by the presence or absence of HPL-derived metabolites. For comparison, representative photographs of each genotype 72 hpi is shown. Graphs are the means±SD of 24 replicates for each genotype. Bar = 1 cm. (D) Analyses of camalexin accumulation levels for leaves collected at 72 hpi (<i>gl-1</i>, <i>aos-hpl</i> and <i>aos-HPL-OE</i>) or 96 hpi (Col and <i>HPL-OE</i>) show negligible levels of camalexin in all plant genotypes with dysfunctional <i>AOS.</i> The <i>HPL-OE</i> lines contain 30% less camalexin than that in Col lines, potentially because of the reduced JA levels in these plants. Graphs are the means±SD of 24 replicates for each genotype. Within any given treatment, bars with different letters indicate significant differences (<i>P</i><0.005, Tukey's test).</p

Profiling of the HPL- and AOS-branch pathways metabolites.

<p>(A) Levels of C₆-aldehydes, (B) JAs (JA+MeJA), and (C) 12-OPDA determined in non wounded (grey bar), or wounded leaves 2 hours after mechanical damage (black bar). Each measurement is derived from the mean±standard deviation (SD) of three independent biological replicates. (D) Characterization and quantification of GLVs by adsorptive headspace collection and GC-MS analyses performed on three repeats of three independent biological replicates from wounded and non wounded <i>Arabidopsis</i> genotypes show that hexenyl acetate is the predominant volatile produced in wounded leaves of plants with a functional <i>HPL</i>. Double-headed arrow represents a scale for signal intensity. (E) Analyses of the emission rate of hexenyl acetate in non wounded (grey bar) or mechanically wounded (black bar) <i>aos-HPL-OE</i> plants, performed three times on three independent biological replicates show that emission of hexenyl acetate is wound-inducible and transient.</p

Attraction of parasitoid wasp, <i>Aphidius colemani,</i> to the <i>in vivo</i> wound-induced or chemically synthesized hexenyl acetate.

<p>(A) Characterization and quantification of GLVs by adsorptive headspace collection and GC-MS analyses performed on three repeats of five independent biological replicates from intact and aphid infested <i>aos-hpl</i> and <i>aos-HPL-OE</i> genotypes show that hexenyl acetate is the predominant volatile produced in aphid infested plants with a functional <i>HPL</i>. (B) Volatile bioassays using glass Y-tube olfactometer was employed to determine the response of <i>A. colemani</i> to the volatile blend produced from mechanically wounded <i>aos-hpl</i> and <i>aos-HPL-OE</i> plant genotypes. The bar graph represents the number of parasitoids examined and shows that they are significantly attracted more to the wounded <i>aos</i>-<i>HPL-OE</i> than to the <i>aos-hpl</i> plants (<i>P</i> = 0.016). (C) Volatile bioassays using glass Y-tube olfactometer was employed to determine the response of <i>A. colemani</i> to the presence or absence of synthetic hexenyl acetate in chambers containing wounded <i>aos-hpl</i> plant genotype. The bar graph represents the number of parasitoids examined and shows that they are significantly attracted towards the chamber of wounded <i>aos-hpl</i> plants with hexenyl acetate-spotted filters as compared to the plant chamber containing the same plant genotype but with hexane-spotted filters as the control (<i>P</i> = 0.034). One-tailed binomial tests were used to determine significance.</p

Function of C₆-aldehydes in plant protection against necrotrophic fungi <i>Botrytis cinerea and Alternaria brassicicola</i>.

<p>Lesion development was monitored and compared between leaves from <i>aos-hpl</i> vs. <i>aos-HPL-OE</i> plants at 72h post inoculation (hpi) with conidia from either <i>B. cinerea</i> or from <i>A. brassicicola.</i> Each bar represents average lesion diameter±SD of 24 replicates for each genotype.</p

Choice test with the leafminer (<i>Liriomyza trifolii)</i>.

<p>Attraction of two-day old female leafminers to <i>aos-HPL-OE</i> versus <i>aos</i>-<i>hpl</i> plants was tested using glass Y-tube olfactometer. Each leafminer was introduced individually into the base of the Y-tube and its choice was recorded. The bar graph represents the numbers of herbivores examined and shows that they are equally attracted to the <i>aos</i>-<i>HPL-OE</i> and to the <i>aos-hpl</i> plants. One-tailed binomial tests were performed to determine the significance. (<i>P</i> = 0.443).</p