Addition of transcription activator-like effector binding sites to a pathogen strain-specific rice bacterial blight resistance gene makes it effective against additional strains and against bacterial leaf streak
Article first published online: 2 JUL 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 195, Issue 4, pages 883–893, September 2012
How to Cite
Hummel, A. W., Doyle, E. L. and Bogdanove, A. J. (2012), Addition of transcription activator-like effector binding sites to a pathogen strain-specific rice bacterial blight resistance gene makes it effective against additional strains and against bacterial leaf streak. New Phytologist, 195: 883–893. doi: 10.1111/j.1469-8137.2012.04216.x
- Issue published online: 2 AUG 2012
- Article first published online: 2 JUL 2012
- Received: 15 March 2012, Accepted: 22 May 2012
- effector-triggered immunity;
- gene regulation;
- plant disease resistance;
- R gene;
- resistance gene;
- TAL effector;
- •Xanthomonas transcription activator-like (TAL) effectors promote disease in plants by binding to and activating host susceptibility genes. Plants counter with TAL effector-activated executor resistance genes, which cause host cell death and block disease progression. We asked whether the functional specificity of an executor gene could be broadened by adding different TAL effector binding elements (EBEs) to it.
- •We added six EBEs to the rice Xa27 gene, which confers resistance to strains of the bacterial blight pathogen Xanthomonas oryzae pv. oryzae (Xoo) that deliver the TAL effector AvrXa27. The EBEs correspond to three other effectors from Xoo strain PXO99A and three from strain BLS256 of the bacterial leaf streak pathogen Xanthomonas oryzae pv. oryzicola (Xoc).
- •Stable integration into rice produced healthy lines exhibiting gene activation by each TAL effector, and resistance to PXO99A, a PXO99A derivative lacking AvrXa27, and BLS256, as well as two other Xoo and 10 Xoc strains virulent toward wildtype Xa27 plants. Transcripts initiated primarily at a common site. Sequences in the EBEs were found to occur nonrandomly in rice promoters, suggesting an overlap with endogenous regulatory sequences.
- •Thus, executor gene specificity can be broadened by adding EBEs, but caution is warranted because of the possible coincident introduction of endogenous regulatory elements.