Interactions between transgene and inherent plant resistance mechanisms
Background
The environmental impact of genetically engineered (transgenic) plants is a major concern arising from the use of these novel crops. In a number of instances commercially grown insect-resistant Bt crops have been shown to suffer increased damage from non-target herbivores.
The mechanisms underlying the occurrence of secondary pests in insect-resistant transgenic crops have not yet been elucidated. Generally it is assumed that this phenomenon is simply a reflection of the fact that these pests benefit from the reduction in applications of broad spectrum insecticides against lepidopteran pests in Bt crops.
Our ongoing research has shown that changes in plant physiology caused by shifts in herbivore pressure, represents an alternative mechanism explaining increased crop susceptibility to secondary pests. This novel mechanism has important implications for resistance management and non target pest control in transgenic crops.