PMC

Drosera capensis leaf 12 h after insect prey capture. Scale bar, 1 cm.

Three Drosera capensis leaves treated with three 10 µl-drops JA-Ile (jasmonic acid–isoleucine conjugate, 100 µM) at the same time in the centre of the adaxial site of the intact leaf. The leaves shown represent three different plants. Photograph taken after 12 h, immediately after cutting off the leaves. Scale bar, 1 cm.

Drosera capensis leaves treated with different modes of prey: two living individuals of Drosophila melanogaster (D. m.); two dead individuals of D. melanogaster (D. m. †); a small stone with the size of two fruitflies; challenge with a brush for 15 min; freshly crushed D. melanogaster (D. m., crushed). The leaves shown represent three different plants. Each single photo was taken after 12 h, immediately after cutting off the leaves. Arrows indicate the position of the prey. Scale bars, 1 cm. (Online version in colour.)

(a) Definition of Drosera capensis leaf segments observed 3 h after fruitfly capture; u, upper; m, middle; l, lower. (b) Phytohormone analyses of the various segments (9–12 leaves were collected for each single measurement); indicated is the increase in the respective phytohormone 3 h after capture of two Drosophila melanogaster compared with the control. From left to right: jasmonic acid (black bar), jasmonic acid–isoleucine conjugate (grey bar), indole-3-acetic acid (white bar); exact values are given above the bars (n = 3). Asterisks indicate significant differences between treatments; n.s., not significant (ANOVA, SNK-test, p < 0.001 for JA and JA-Ile, p < 0.003 for IAA).

Kinetics of leaf bending in Drosera capensis. (a) Control leaves and (b) leaves after capture of two living Drosophila melanogaster. Arrows indicate the position of the flies. Scale bars, 1 cm. (c) Phytohormone concentrations (ng per g fresh weight; 3–5 leaves were collected for one single measurement) in D. capensis leaves treated with (white circle) and without (black circle) D. melanogaster after 45, 90 and 180 min (mean ± s.d.; n = 5). Asterisks indicate significant differences between treatments; n.s., not significant (ANOVA, SNK-test, p < 0.001). Five leaves were collected for each single time point. All phytohormones were analysed in parallel from the same samples. IAA, indole-3-acetic acid; JA, jasmonic acid; JA-Ile, jasmonic acid–isoleucine conjugate. (Online version in colour.)