Insect effectors and gene-for-gene interactions with host plants

Within the context of the four-phase model of plant immunity, gene-for-gene interactions have gained new relevance. Genes conferring resistance to the Asian rice gall midge (Orseolia oryzae) and the small brown planthopper (Nilaparvata lugens) have been cloned in rice (Oryza sativa). Mutations in insect avirulence genes that defeat plant resistance have been identified and cloned. Results are consistent with both the gene-for-gene hypothesis and the new model of plant immunity. Insect resistance genes encode proteins with nucleotide binding sites and leucine-rich repeats. Insects use effectors that elicit effector-triggered immunity. At least seven-percent of Hessian fly genes are effector encoding.