Different Generations of Genetically Modified Crops for Insect Resistance

Crops are exposed to a variety of insect pests throughout their lifetime. Insect pests cause significant damage to crop plants by feeding on their tissues or sap. Besides the conventional methods which are based on using chemicals, the genetic transformation of plants with insecticidal toxin genes such as Bt has been widely applied to control insect pests. In addition to Bt genes, other toxin genes from different sources were also transferred to plants. Transgenic plants have been on the market for over two decades and have had remarkable achievements so far. However, current restrictions on these products, as well as public concern make scientists explore new approaches. The advent of RNA interference technology and later the CRISPR/Cas genome editing tool has opened up a promising new avenue in the development of next-generation biotech crops. These new approaches allow scientists to introduce new plant genotypes resistant to pests and diseases without transferring toxin genes, and all it takes is to edit target regions in the genome or apply modifications to the host transcriptome content. In this chapter, we will review different generations of biotech crops developed for insect resistance.