Genetics and Biochemistry of Insect Resistance in Maize

Abstract

Insects are a major concern for maize production worldwide. Host plant resistance to insects involves a number of chemical and biochemical factors that limit, but rarely eliminate insect damage. Most chemical and many biochemical factors involved in resistance to insects are synthesized independent of the pest as phytoanticipines. These factors are stored in sequestered forms that are modified to active structures upon insect infestation and tissue damage. Because the genetic basis of varietal responses to insects for maize is quantitative in nature, quantitative trait locus analysis has been a standard approach to describe insect resistance. These Studies often examined cot-related biochemical traits to link genetic loci with biological mechanisms. Recently there has been a realization of the importance of herbivore enemies that are attracted by maize in response to herbivore damage. Upon infestation, maize releases volatile chemicals to actively recruit parasitic wasps or nematodes to combat the insect pests. In this review we examine the current state of knowledge of the biochemical, genetic and plant-insect tritrophic mechanisms involved in maize resistance to insect pests.