Plant Science Department, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa.
J Exp Bot. 2010 Oct;61(15):4169-83. doi: 10.1093/jxb/erq166. Epub 2010 Jun 25.
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.
蛋白酶抑制剂是一种很有前途的补充手段，可以与 Bt 毒素一起用于开发抗虫转基因作物，但它们对蛋白水解酶的特异性有限，以及在生物体中普遍存在的依赖蛋白酶的过程，引起了人们对它们在农业生态系统中最终的非靶标效应的质疑。在简要概述了影响抗虫转基因作物对非靶标生物的主要因素之后，本文从多营养层的角度讨论了蛋白酶抑制剂的可能影响，不仅考虑了靶标草食性动物的蛋白酶，还考虑了沿着食物链发现的其他生物体的蛋白酶，包括植物本身。近年来，在设计高效广谱抑制剂以及部署具有抗主要草食性害虫的表达蛋白酶抑制剂的转基因植物方面取得了重大进展。对现有文献的全面评估表明，尽管重组蛋白酶抑制剂在植物食物网中的非特异性抑制作用通常可以忽略不计，但其在植物体内的“意外”多效性可能具有潜在的农业价值，但这些蛋白质的无害性可能仍然是一个需要逐个案例进行经验评估的问题。
