Recombinant protease inhibitors for herbivore pest control: a multitrophic perspective

• Published in: Journal of experimental botany 2010-10, Vol.61 (15), p.4169-4183
• Main Authors: Schlüter, Urte, Benchabane, Meriem, Munger, Aurélie, Kiggundu, Andrew, Vorster, Juan, Goulet, Marie-Claire, Cloutier, Conrad, Michaud, Dominique
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Animals; Beetles; Biological and medical sciences; Cystatins; Feeding Behavior - drug effects; Fundamental and applied biological sciences. Psychology; Genetic engineering applications; Genetics and breeding of economic plants; Herbivores; Insect biochemistry; Insect larvae; Insect-resistant transgenic plants; Insecta - drug effects; Insecta - physiology; non-target organisms; Pest Control, Biological; Plant breeding: fundamental aspects and methodology; Plants; Plants, Genetically Modified; pleiotropic effects; Protease inhibitors; Protease Inhibitors - pharmacology; protease–inhibitor interactions; Recombinant Proteins - pharmacology; REVIEW PAPER; Transgenic insects; Transgenic plants; Trypsin inhibitors
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/erq166

Protease inhibitors are a promising complement to Bt toxins for the development of insect-resistant transgenic crops, but their limited specificity against proteolytic enzymes and the ubiquity of protease-dependent processes in living organisms raise questions about their eventual non-target effects in agroecosystems. After a brief overview of the main factors driving the impacts of insect-resistant transgenic crops on non-target organisms, the possible effects of protease inhibitors are discussed from a multitrophic perspective, taking into account not only the target herbivore proteases but also the proteases of other organisms found along the trophic chain, including the plant itself. Major progress has been achieved in recent years towards the design of highly potent broad-spectrum inhibitors and the field deployment of protease inhibitor-expressing transgenic plants resistant to major herbivore pests. A thorough assessment of the current literature suggests that, whereas the non-specific inhibitory effects of recombinant protease inhibitors in plant food webs could often be negligible and their 'unintended' pleiotropic effects in planta of potential agronomic value, the innocuity of these proteins might always remain an issue to be assessed empirically, on a case-by-case basis.