A Decade Decoded: Spies and Hackers in the History of TAL Effectors Research

Annu Rev Phytopathol. 2019 Aug 25;57:459-481. doi: 10.1146/annurev-phyto-082718-100026. Epub 2019 Aug 6.


Transcription activator-like effectors (TALEs) from the genus Xanthomonas are proteins with the remarkable ability to directly bind the promoters of genes in the plant host to induce their expression, which often helps bacterial colonization. Metaphorically, TALEs act as spies that infiltrate the plant disguised as high-ranking civilians (transcription factors) to trick the plant into activating weak points that allow an invasion. Current knowledge of how TALEs operate allows researchers to predict their activity (counterespionage) and exploit their function, engineering them to do our bidding (a Manchurian agent). This has been possible thanks particularly to the discovery of their DNA binding mechanism, which obeys specific amino acid-DNA correspondences (the TALE code). Here, we review the history of how researchers discovered the way these proteins work and what has changed in the ten years since the discovery of the code. Recommended music for reading this review can be found in the Supplemental Material.

Keywords: TAL effectors; biotechnology; evolution; history.

Publication types

  • Review

MeSH terms

  • Bacterial Proteins
  • Plant Diseases
  • Transcription Activator-Like Effectors*
  • Transcription Factors
  • Xanthomonas*


  • Bacterial Proteins
  • Transcription Activator-Like Effectors
  • Transcription Factors