VIRUS-DERIVED GENES FOR INSECT-RESISTANT TRANSGENIC PLANTS Sijun Liu, Huarong Li, S. Sivakumar, and Bryony C. Bonning Department of Entomology, Iowa State University, Ames, Iowa 50011 I. Introduction A. Baculoviruses and Entomopoxviruses B. Bioinformatics for Identification of Genes Involved in Virus–Host Interaction II. Enzymes That Target the Peritrophic Membrane A. Physiology of the Peritrophic Membrane B. Enhancin C. Chitinase D. Chitin-Binding Proteins III. Enzymes That Target the Basement Membrane A. Physiology of the Basement Membrane B. Matrix Metalloproteases C. Cathepsins IV. Delivery of Intrahemocoelic Toxins from Plants A. Intrahemocoelic Toxins B. Lectins V. Concluding Remarks References ABSTRACT Insect viruses have evolved to counter physiological barriers to infection presented by the host insect. For the Lepidoptera (butterflies and moths), these barriers include (1) the peritrophic membrane (PM) lining the gut, which presents a physical barrier to virus infection of the midgut epithelial cells, (2) the basement membrane (BM) that overlies the gut thereby restricting secondary infection of other tissues, and (3) the immune system of the host insect. Hence, insect viruses provide a resource for genes that disrupt host physiology in a specific manner, and these genes in turn serve as a resource both for the study of physiological processes, and for disruption of these pro- cesses for pest management purposes. There are several examples of the application of genes used by an insect virus to overcome the PM barrier for production of insect-resistant transgenic plants. There are other examples of intrahemocoelic effectors, such as BM-degrading proteases that can only be used with an appropriate system for delivery of the agent from the gut into the hemocoel (body cavity) of 427 Copyright 2006, Elsevier Inc. All rights reserved. 0065-3527/06 $35.00 DOI: 10.1016/S0065-3527(06)68012-3 ADVANCES IN VIRUS RESEARCH, VOL 68