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Effets et modes d'action des deux lectines à mannose sur le puceron du pois, Acyrthosiphon pisum (Harris) - Potentiel d'utilisation des lectines végétales pour la création de plantes transgéniques résistantes aux pucerons

Abstract : The aim of this study is to identify proteins that are deleterious to aphids (Homoptera; Aphididae), and to determine the mechanisms of action of some of them. This work is a first step in a defence strategy against aphids based upon the use of transgenic plants expressing such toxic plant proteins.
Amongst the molecules tested, two mannose-binding lectins, ConA and GNA, from jackbean (Canavalia ensiformis) and snowdrop (Galanthus nivalis) respectively, induced significant mortality and growth inhibitory effects on aphid nymphal development; these were thus chosen for subsequent investigations.
Dose-response curves of mannose binding lectins were shown to differ substantially between the six aphid species tested. At sub-lethal doses GNA and ConA adversely affected total fecundity and the dynamics of reproduction of both pea aphid, Acyrthosiphon pisum (Harris), and peach-potato aphid, Myzus persicae Sulzer. ConA acted as an antifeedant, but not as a feeding deterrent. On the model aphid A. pisum, high levels of ConA significantly altered ingestion rates, but at moderate levels, insects appeared to exhibit a time-dependent tolerance of the antifeedant. The stomach and anterior part of the midgut were shown to be the primary physiological targets of ConA. As a result of its binding to epithelial cells, the lectin was shown to induce hypertrophic growth of these cells and subsequent shedding of the membrane surface. Competitive experiments with different mannosides suggested that this interaction appeared not to be simply a consequence of binding of the lectin to mannose residues. Both ConA and GNA caused distinct disturbances in the steady-state levels of free amino acids in the aphid, but the effects of the two lectins differed significantly from each other.
Effects of lectins are discussed in relation to the use of transgenic plants expressing such toxic proteins for potential control of aphid populations.
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https://tel.archives-ouvertes.fr/tel-00007006
Contributor : Nicolas Sauvion <>
Submitted on : Thursday, September 30, 2004 - 2:40:28 PM
Last modification on : Friday, January 8, 2021 - 9:34:03 AM
Long-term archiving on: : Friday, April 2, 2010 - 8:16:37 PM

Identifiers

  • HAL Id : tel-00007006, version 1
  • PRODINRA : 318765

Citation

Nicolas Sauvion. Effets et modes d'action des deux lectines à mannose sur le puceron du pois, Acyrthosiphon pisum (Harris) - Potentiel d'utilisation des lectines végétales pour la création de plantes transgéniques résistantes aux pucerons. Sciences du Vivant [q-bio]. INSA de Lyon, 1995. Français. ⟨tel-00007006⟩

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