Crops resistant to insect attack o†er an alternative strategy of pest
control to a total reliance upon chemical pesticides. Transgenic plant technology
can be a useful tool in producing resistant crops, by introducing novel resistance
genes into a plant species. This technology is seen very much as forming an
integral component of a crop management programme.
Several di†erent classes of plant proteins have been shown to be insecticidal
towards a range of economically important insect pests from di†erent orders; in
some cases a role in the defence of speciÐc plant species against phytophagous
insects has been demonstrated. Genes encoding insecticidal proteins have been
isolated from various plant species and transferred to crops by genetic engineering.
Amongst these genes are those that encode inhibitors of proteases (serine
and cysteine) and a-amylase, lectins, and enzymes such as chitinases and lipoxygenases.
Examples of genetically engineered crops expressing insecticidal plant proteins
from di†erent plant species, with enhanced resistance to one or more insect pests
from the orders Lepidoptera, Homoptera and Coleoptera are presented. The
possibility of “pyramidingÏ di†erent resistance genes to improve the e†ectiveness
of protection and durability is discussed and exempliÐed. The number of di†erent
crop species expressing such genes is very diverse and ever-increasing. The viability
of this approach to crop protection is considered. 1998 SCI.