Improving immunity in crops: new tactics in an old game.

Crop disease remains a major cause of yield loss and emerging diseases pose new threats to global food security. Despite the dearth of commercial development to date, progress in using our rapidly expanding knowledge of plant-pathogen interactions to invent new ways of controlling diseases in crops has been good. Many major resistance genes have now been shown to retain function when transferred between species, and evidence indicates that resistance genes are more effective when deployed in a background containing quantitative resistance traits. The EFR pattern-recognition receptor, present in only the Brassicaceae, functions to provide bacterial disease control in the Solanaceae. Knowledge of how transcription activator-like effectors bind DNA is leading to new methods for triggering disease resistance and broader applications in genome engineering.