A TAL effector from Xanthomonas oryzae pv. oryzicola may contribute to virulence by targeting a transcription factor
Z. DUBROW (1), L. Wang (1), A. Bogdanove (1) (1) Cornell University, U.S.A.

Transcription activator-like (TAL) effectors from Xanthomonas spp. target specific host genes to influence disease development. Xanthomonas oryzae comprises two pathovars, oryzae and oryzicola, the causal agents of bacterial blight and leaf streak of rice. These diseases have a severe economic impact on rice cultivation in Africa, India, and East Asia. We have characterized a TAL effector from Xanthomonas oryzae pv. oryzicola (Xoc) that contributes approximately 10% of virulence. Two targets were previously identified. New evidence suggests that some TAL effectors may activate genes by binding to non-canonical motifs, including motifs on the reverse, rather than the forward, DNA strand.  Based on this, a third target was identified on the reverse strand of the promoter of a transcription factor. We have constructed 13 designer TAL effectors (dTALEs) to individually target each of the three genes upregulated by the TAL effector. By expressing these dTALEs in a Xoc knockout mutant we will determine which, if any, of these targets is a major susceptibility gene. By targeting transcription factors, TAL effectors can modulate whole regulatory networks to affect pathogenesis in complex ways.  We will investigate the downstream effects of the TAL effector target(s) to uncover essential components of plant susceptibility.     

Abstract Number: P9-252
Session Type: Poster