Alkaloid Biosynthesis and the Consequences of a NA Oversupply

<p>Biosynthesis scheme and proportion of unlabeled (M⁺) and labeled (M⁺+4, M⁺+8) nicotine and anatabine in the leaves of two independently transformed N. attenuata IR<i>pmt</i> lines (108 and 145) and WT plants 5 d after elicitation with 150 μg of MeJA per plant. Plants were grown in hydroponic solutions and supplied with either unlabeled or D₄-ring-labeled NA ethyl ester (1 mM) 24 h after elicitation (<i>n</i> = 3 or 4). The oversupply of NA resulted in the formation of anatabine even in WT plants from both labeled exogenous and unlabeled endogenous NA pools.</p

Comparison of Antisense and Inverted-Repeat Silencing of <i>pmt</i>

<p>Nicotine content (mean of 5–6 plants/line) normalized to mean of WT of unelicited (control) N. attenuata plants and plants 5 d after elicitation with 150 μg of MeJA per plant from independent lines transformed with (A) antisense <i>pmt</i> constructs and (B) an IR<i>pmt</i> construct. In contrast to the 31 lines transformed with the antisense <i>pmt</i> construct, 29 of the 34 IR<i>pmt</i> lines had dramatically reduced constitutive and MeJA-induced nicotine levels. T, terminator; P, promoter; I, spliceable intron; arrow, 950-bp consensus fragment of <i>pmt1</i> and <i>pmt2</i>. For details of transformation constructs see Protocol S1.</p

MOESM1 of Sequential above- and belowground herbivory modifies plant responses depending on herbivore identity

Additional file 1. Number of root galls (knots) induced by the nematodes

PMT Transcript and Alkaloid Levels of IR<i>pmt</i> Lines

<p>Mean (± SE) relative PMT mRNA transcript levels in the roots (A), and leaf levels of (B) nicotine and (C) anatabine, in two independent lines of IR<i>pmt</i>-transformed (108 and 145) and WT N. attenuata plants. Elicited (150 μg of MeJA) and unelicited (control) plants were harvested at 10 h for transcript (A) and at 4 d for alkaloid (B and C) quantification. Both IR<i>pmt</i> lines had significantly reduced PMT transcript and nicotine but featured anatabine not present in WT plants. Lowercase letters signify differences at <i>p</i> ≤ 0.01, Bonferroni corrected ([A] <i>n</i> = 3, ANOVA: F_2,12 = 12.55; [B] <i>n</i> = 8–10, ANOVA: F_2,50 = 135.4; [C] <i>n</i> = 8–10, ANOVA: F_2,50 = 39.611]. n.d., not detected.</p

Pappas_et_al_all data

Pappas_et_al_all dat

Local and systemic effects of plant exposure to <i>Macrolophus pygmaeus</i> on tomato proteinase inhibitor levels.

<p>Mean (+/- SE) of (A) proteinase inhibitor (PI) activity relative to protein content (N = 18/19 for control/exposed plants) and (B) transcript accumulation of <i>PI-I</i> and <i>PI-II</i> genes (N = 5/6 for control/exposed plants, each replicate representing 3 plants) in the local leaflet (Lf) exposed to 5 young <i>M</i>. <i>pygmaeus</i> females (dark bars) in clip cages for 4 days (depicted in inset i) and in unexposed control plants (white bars). Transcript accumulation expressed relative to control plants was assessed by real time PCR in relation to ubiquitin as reference gene. (C, D) PI activity relative to protein content (mean +/- SE, N = 10/9 for control/exposed plants) of a systemic leaf (L5, pooled Lf 2–4) either directly after (C: No delay) or 4 additional days after (D: Delay) a 4-day exposure of an older leaf (L2), to either 5 young adult females or 10 nymphs of <i>M</i>. <i>pygmaeus</i> (depicted in inset ii). Significant differences between exposed and control plants are indicated by asterisks following a GLM: n.s.: not significant, <i>P</i> < 0.05 (*), <i>P</i> < 0.01 (**).</p

Persistence of plant-mediated effects of <i>Macrolophus pygmaeus</i> on the performance of <i>Tetranychus urticae</i>.

<p>(A) Number of eggs per plant and (B) survival of females of <i>T</i>. <i>urticae</i> (mean +/- SE of 8 plants) 2 weeks after exposure of young plants to 2 <i>M</i>. <i>pygmaeus</i> females for 4 days (dark bars, setup is depicted in inset) or the corresponding control plants (white bars). Significant differences between exposed plants and control plants are indicated by asterisks following a GLMM: <i>P</i> < 0.05 (*), <i>P</i> < 0.001 (***).</p