title: Targeted promoter editing for rice resistance to Xanthomonas oryzae pv. oryzae reveals differential activities for SWEET14-inducing TAL effectors.
abstract: As a key virulence strategy to cause bacterial leaf blight, Xanthomonas oryzae pv. oryzae (Xoo) injects into the plant cell DNA-binding proteins called transcription activator-like effectors (TALEs) that bind to effector-binding elements (EBEs) in a sequence-specific manner, resulting in host gene induction. TALEs AvrXa7, PthXo3, TalC and Tal5, found in geographically distant Xoo strains, all target OsSWEET14, thus considered as a pivotal TALE target acting as major susceptibility factor during rice-Xoo interactions. Here, we report the generation of an allele library of the OsSWEET14 promoter through stable expression of TALE-nuclease (TALEN) constructs in rice. The susceptibility level of lines carrying mutations in AvrXa7, Tal5 or TalC EBEs was assessed. Plants edited in AvrXa7 or Tal5 EBEs were resistant to bacterial strains relying on the corresponding TALE. Surprisingly, although indels within TalC EBE prevented OsSWEET14 induction in response to BAI3 wild-type bacteria relying on TalC, loss of TalC responsiveness failed to confer resistance to this strain. The TalC EBE mutant line was, however, resistant to a strain expressing an artificial SWEET14-inducing TALE whose EBE was also edited in this line. This work offers the first set of alleles edited in TalC EBE and uncovers a distinct, broader range of activities for TalC compared to AvrXa7 or Tal5. We propose the existence of additional targets for TalC beyond SWEET14, suggesting that TALE-mediated plant susceptibility may result from induction of several, genetically redundant, host susceptibility genes by a single effector.
authors.affiliation: UMR Interactions Plantes Microorganismes Environnement (IPME), IRD-CIRAD-Université, Montpellier, France.
authors.forename: Servane
authors.initials: S
authors.lastname: Blanvillain-Baufumé
authors.affiliation: Institut für Biologie, Institutsbereich Genetik, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Maik
authors.initials: M
authors.lastname: Reschke
authors.affiliation: Institut für Biologie, Institutsbereich Genetik, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Solé
authors.affiliation: UMR Interactions Plantes Microorganismes Environnement (IPME), IRD-CIRAD-Université, Montpellier, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Auguy
authors.affiliation: UMR Interactions Plantes Microorganismes Environnement (IPME), IRD-CIRAD-Université, Montpellier, France.
authors.forename: Hinda
authors.initials: H
authors.lastname: Doucoure
authors.affiliation: UMR Interactions Plantes Microorganismes Environnement (IPME), IRD-CIRAD-Université, Montpellier, France.
authors.forename: Boris
authors.initials: B
authors.lastname: Szurek
authors.affiliation: CIRAD, UMR AGAP (Amélioration génétique et Adaptation des Plantes), Montpellier, France.
authors.forename: Donaldo
authors.initials: D
authors.lastname: Meynard
authors.affiliation: CIRAD, UMR AGAP (Amélioration génétique et Adaptation des Plantes), Montpellier, France.
authors.forename: Murielle
authors.initials: M
authors.lastname: Portefaix
authors.affiliation: UMR Interactions Plantes Microorganismes Environnement (IPME), IRD-CIRAD-Université, Montpellier, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Cunnac
authors.affiliation: CIRAD, UMR AGAP (Amélioration génétique et Adaptation des Plantes), Montpellier, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Guiderdoni
authors.affiliation: Institut für Biologie, Institutsbereich Genetik, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Boch
authors.affiliation: UMR Interactions Plantes Microorganismes Environnement (IPME), IRD-CIRAD-Université, Montpellier, France.
authors.forename: Ralf
authors.initials: R
authors.lastname: Koebnik
mesh_terms: D060467:Disease Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D012275:Oryza / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014974:Xanthomonas / Q000472:pathogenicity*
chemical_list: D010940:Plant Proteins
keywords: TALEN; bacterial leaf blight; genome engineering; susceptibility gene; transgene-free plants