TAL effectors: finding plant genes for disease and defense

Transcription activator like effectors (TALEs) are injected via the type Ill secretion pathway of many plant pathogenic Xanthomonas spp. into plant cells where they contribute to disease or trigger resistance by binding to DNA and turning on TALE-specific host genes. Advances in our understanding of TALEs and their targets have yielded new models for pathogen recognition and defense. Similarly, we have gained insight into plant molecules and processes that can be co-opted to promote infection. Recent elucidation of the basis for specificity in DNA binding by TALEs expedites further discovery and opens the door to biotechnological applications. This article reviews the most significant findings in TALE research, with a focus on recent advances, and discusses future prospects including pressing questions yet to be answered.