The Rice Locus Is a Bidirectional Target of the African pv. Major Transcription Activator-like Effector TalC but Does Not Contribute to Disease Susceptibility.

pv. () strains that cause bacterial leaf blight (BLB) limit rice () production and require breeding more resistant varieties. Transcription activator-like effectors (TALEs) activate transcription to promote leaf colonization by binding to specific plant host DNA sequences termed effector binding elements (EBEs). major TALEs universally target susceptibility genes of the SWEET transporter family. TALE-unresponsive alleles of clade III susceptibility gene promoter created with genome editing confer broad resistance on Asian strains. African strains rely primarily on the major TALE TalC, which targets . Although the virulence of a mutant strain is severely impaired, abrogating induction with genome editing does not confer equivalent resistance on African . To address this contradiction, we postulated the existence of a TalC target susceptibility gene redundant with . Bioinformatics analysis identified a rice locus named ATAC composed of the () gene and a putative lncRNA that are shown to be bidirectionally upregulated in a TalC-dependent fashion. Gain-of-function approaches with designer TALEs inducing ATAC sequences did not complement the virulence of a strain defective for gene activation. While editing the TalC EBE at the ATAC loci compromised TalC-mediated induction, multiplex edited lines with mutations at the and ATAC loci remained essentially susceptible to African strains. Overall, this work indicates that ATAC is a probable TalC off-target locus but nonetheless documents the first example of divergent transcription activation by a native TALE during infection.