QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online July 26, 2004
Journal of Experimental Biology 207, 2947-2963 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01128

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gorb, E. Articles by Gorb, S. Search for Related Content PubMed PubMed Citation Articles by Gorb, E. Articles by Gorb, S.

Structure and properties of the glandular surface in the digestive zone of the pitcher in the carnivorous plant Nepenthes ventrata and its role in insect trapping and retention

Elena Gorb^1,*, Victoria Kastner¹, Andrei Peressadko¹, Eduard Arzt¹, Laurence Gaume², Nick Rowe² and Stanislav Gorb¹

¹ Evolutionary Biomaterials Group, Max Planck Institute for Metals Research, Heisenbergstr. 3, D-70569 Stuttgart, Germany
² Botanique et Bioinformatique de l'Architecture des Plantes, UMR CNRS 5120, Boulevard de la Lironde - TA40/PS2, F-34398 Montpellier, Cedex 5, France

View larger version (35K): [in a new window]   Fig. 1. Experimental set-up for estimation of material properties by microindentation. SS, sapphire sphere; FOS, fibre optical sensor; GS, glass spring; MR, mirror; PS, plant sample.

View larger version (19K): [in a new window]   Fig. 2. Typical force-distance curves used for evaluation of elasticity and adhesive properties of the surface. (A) Without adhesion. (B) With adhesion. Fa, adhesion force; Fn, maximal applied force; Loading, part of the curve corresponding to the loading process; Retracting, part of the curve corresponding to the retracting process.

View larger version (21K): [in a new window]   Fig. 3. Experimental set-up for friction force measurements (A) and a typical force-time curve (B) used for estimation of maximal friction force (Ffr) generated by insects. FS, force sensor; HR, hair; IN, insect; PC, computer; SC, sensor control; SP, support; TS, tested surface.

View larger version (130K): [in a new window]   Fig. 4. SEM micrographs of the glandular surface. (A) General view of the surface. (B) Gland of the upper part of the digestive zone. (C) Gland of the middle part of the digestive zone. (D) Surface of the gland. (E) Crystals on the gland surface. Arrows show the direction to the peristome. CR, crystal; GL, gland; HD, hood.

View larger version (43K): [in a new window]   Fig. 5. 3-D images (A,C,E) and profiliograms (B,D,F) of different parts of the glandular surface. (A,B) Part between glands (objective 50, magnification 50x0.4). (C,D) Gland in the upper part of the digestive zone (objective 20, magnification 20x1.3). (E,F) Gland in the middle part of the digestive zone (objective 20, magnification 20x2.0). Arrows in A,C,E show the axes for profiles in B,D,F, respectively.

View larger version (169K): [in a new window]   Fig. 6. Anatomy of the digestive zone (light microscopy). (A) Transverse section of the pitcher wall. (B) Longitudinal and (C) transverse sections of the gland, general view. (D) Longitudinal section of the glandular head. (E-G) Transverse sections of the gland. Arrows show the direction to the peristome. CU, cuticle; EC, endodermoid component; ED, epidermal depression; GH, glandular head; HD, hood; IE, inner epidermis; IM, inner margin of the cell wall; IW, internal cell wall; LW, lateral cell wall; ME, mesophyll; OE, outer epidermis; OM, outer margin of the cell wall; OW, outer cell wall; SI, secretion inclusion; SL, second layer of cells; TL, third layer of cells; TR, tracheid element. Scale bar: A,D, 20 µm; B,C,E-G, 50 µm.

View larger version (60K): [in a new window]   Fig. 7. Anatomy of the digestive zone (fluorescence microscopy). (A,B) Transverse section of the gland in a light (A) and fluorescence microscope (B). (C) Whole-mounted surface preparation in a fluorescence microscope. Arrow shows the direction to the peristome. EC, endodermoid component; HD, hood; OW, outer cell wall. Scale bar: 100 µm.

View larger version (19K): [in a new window]   Fig. 8. Microindentation experiments on the glandular surface. (A) Force-time curve indicating that the material of the plant sample exhibited visco-elastic properties. Pitcher surface was loaded during the first 15 s (Load), then kept in contact with the upper sample for the next 45 s (Relaxation). (B) The indentation of the sample vs applied force (points). The solid line indicates the fit of the indentation data with the Hertz theory.

View larger version (15K): [in a new window]   Fig. 9. Dependence of the adhesion force on load. (A) Data of all points on three pitchers. Different symbols correspond to different pitchers. (B,C) Values measured on the same point (selected examples) with increasing applied force. In six out of eight cases, the adhesion increased significantly linearly with the applied force (B), while it remained constant for the other two cases (C). Fa, adhesion force; Fn, applied force.

View larger version (14K): [in a new window]   Fig. 10. Frequency histograms of the distribution of points with different values of the adhesion force (A) and the tenacity (B). Only the value of the first test at each point was taken into account.

View larger version (153K): [in a new window]   Fig. 11. Attachment devices of insect species studied. (A-C) Smooth pulvilli of the bug Pyrrhocoris apterus. (A) Distal part of the tarsus, lateral aspect. (B) Pretarsus, ventral aspect. (C) Surface of the pulvillus. (D,E) Hairy pulvilli of the fly Calliphora vicina. (D) Right pulvillus. (E) Tenent setae with the terminal elements (spatulae). CL, claws; HK, hooked setae; la, lateral direction; PU, pulvilli; SP, spatulae; TA, terminal tarsomere; UT, unguitractor plate; ve, ventral direction.

View larger version (20K): [in a new window]   Fig. 12. Maximal friction force generated by insects on different substrates. (A) Comparison between three surfaces tested. (B) Comparison between two insect species. According to the Ryan-Eliot-Gabriel-Welsh test of multiple comparisons of means, run after ANOVA, means with different letters differ significantly from each other.