%0 Journal Article
%T Effects of mti-2 Transgenic Potato Plants on the Aphid Myzus persicae (Sternorrhyncha: Aphididae)
%A Julien Saguez
%A Anas Cherqui
%A Salima Lehraiki
%A Charles Vincent
%A Antony Beaujean
%A Lise Jouanin
%A Jean-Claude Laberche
%A Philippe Giordanengo
%J International Journal of Agronomy
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/653431
%X Overexpressed in transgenic plants, protease inhibitors showed insecticidal effects against several insect taxa. We transformed potato internodes with the mustard trypsin inhibitor mti-2 gene. Among the 35 independent transgenic potato lines obtained via Agrobacterium tumefasciens transformation, four (DM6, DM7, DM11, and DM19) were selected for their high level of MTI-2 (at least to 30% of trypsin activity inhibition). Feeding assays were carried out to evaluate their effects on the green-peach aphid, Myzus persicae (Sternorrhyncha: Aphididae). Prereproductive period, nymphal mortality, adult fecundity, and doubling time of M. persicae populations were monitored on nontransformed potato plants (NT) and the four selected DM lines. Compared to NT plants, DM19 did not induce any effect on M. persicae. In contrast, DM7 and DM11 increased nymphal survival by approximately 20%. DM6 and DM11 lines slightly enhanced M. persicae daily fecundity and intrinsic rate of natural increase, leading to a reduction of the doubling time of the populations by 1 day. DM6 did not impact nymphal mortality, whereas with the DM11 almost all the nymphs survived. Potato plants transformed with the mti-2 gene variably affected the life history of M. persicae but did not show any insecticidal effect on the aphid. 1. Introduction Plant protease inhibitors (PIs) have been found in Brassicaceae, Gramineae, Fabaceae, and Solanaceae and are constitutively produced in storage organs [1] to mobilize protein reserves [2], and in seeds to regulate endogenous proteinases during dormancy [3¨C5]. PIs may also be synthesized in plants attacked by insects or pathogens [6¨C8]. Among the different classes of PIs described in plants, serine PIs are the most studied, the two best-characterized families belonging to the Kunitz-type and Bowman-Birk inhibitorĄ¯s family (BBI) [9]. Several serine PIs from different plant origin (e.g., cowpea (Vigna unguiculata), soybean (Glycine max), tomato (Lycopersicon esculentum), potato (Solanum tuberosum) and barley (Hordeum vulgare) were isolated and tested against insects. In vitro studies showed that chymotrypsin and trypsin inhibitors from Nicotiana alata inhibit gut protease activities of the native budworm Helicoverpa punctigera (Lepidoptera) and the black field cricket Teleogryllus commodus (Orthoptera), and reduce their movement and growth [10]. The cowpea trypsin inhibitor (CpTI) delayed larval growth and development in Lacanobia oleracea (Lepidoptera) [11]. Because of their deleterious effects via in vitro delivery, and owing to possibilities offered by
%U http://www.hindawi.com/journals/ija/2010/653431/