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).

Pathogen effector recognition-dependent association of NRG1 with EDS1 and SAG101 in TNL receptor immunity.

Plants utilise intracellular nucleotide-binding, leucine-rich repeat (NLR) immune receptors to detect pathogen effectors and activate local and systemic defence. NRG1 and ADR1 "helper" NLRs (RNLs) cooperate with enhanced disease susceptibility 1 (EDS1), senescence-associated gene 101 (SAG101) and phytoalexin-deficient 4 (PAD4) lipase-like proteins to mediate signalling from TIR domain NLR receptors (TNLs). The mechanism of RNL/EDS1 family protein cooperation is not understood.

A dominant-interfering camta3 mutation compromises primary transcriptional outputs mediated by both cell surface and intracellular immune receptors in Arabidopsis thaliana.

Pattern recognition receptors (PRRs) and nucleotide-binding domain and leucine-rich repeat (LRR)-containing proteins (NLRs) initiate pattern-triggered immunity (PTI) and effector-triggered immunity (ETI), respectively, each associated with the activation of an overlapping set of defence genes. The regulatory mechanism behind this convergence of PTI- and ETI-mediated defence gene induction remains elusive. We generated transgenic Arabidopsis plants that enable conditional NLR activation without pathogen infection to dissect NLR- and PRR-mediated transcriptional signals.

Targeted promoter editing for rice resistance to Xanthomonas oryzae pv. oryzae reveals differential activities for SWEET14-inducing TAL effectors.

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.

The xylan utilization system of the plant pathogen Xanthomonas campestris pv campestris controls epiphytic life and reveals common features with oligotrophic bacteria and animal gut symbionts.

Xylan is a major structural component of plant cell wall and the second most abundant plant polysaccharide in nature. Here, by combining genomic and functional analyses, we provide a comprehensive picture of xylan utilization by Xanthomonas campestris pv campestris (Xcc) and highlight its role in the adaptation of this epiphytic phytopathogen to the phyllosphere. The xylanolytic activity of Xcc depends on xylan-deconstruction enzymes but also on transporters, including two TonB-dependent outer membrane transporters (TBDTs) which belong to operons necessary for efficient growth in the presence of xylo-oligosaccharides and for optimal survival on plant leaves.

Molecular and spatial constraints on NB-LRR receptor signaling.

In plants, a large polymorphic family of intracellular NB-LRR receptors lies at the heart of robust resistance to diverse pathogens and mechanisms by which these versatile molecular switches operate in effector-triggered immunity are beginning to emerge. We outline recent advances in our understanding of NB-LRR receptor signaling leading to disease resistance. Themes covered are (i) NB-LRR molecular constraining forces and their intimate relationship with receptor activation in different parts of the cell, (ii) cooperativity between NB-LRR proteins and the formation of higher order NB-LRR signaling complexes, and (iii) the spatial separation of different resistance branches within cells.

LEAFY target genes reveal floral regulatory logic, cis motifs, and a link to biotic stimulus response.

The transition from vegetative growth to flower formation is critical for the survival of flowering plants. The plant-specific transcription factor LEAFY (LFY) has central, evolutionarily conserved roles in this process, both in the formation of the first flower and later in floral patterning. We performed genome-wide binding and expression studies to elucidate the molecular mechanisms by which LFY executes these roles.

Balanced nuclear and cytoplasmic activities of EDS1 are required for a complete plant innate immune response.

An important layer of plant innate immunity to host-adapted pathogens is conferred by intracellular nucleotide-binding/oligomerization domain-leucine rich repeat (NB-LRR) receptors recognizing specific microbial effectors. Signaling from activated receptors of the TIR (Toll/Interleukin-1 Receptor)-NB-LRR class converges on the nucleo-cytoplasmic immune regulator EDS1 (Enhanced Disease Susceptibility1). In this report we show that a receptor-stimulated increase in accumulation of nuclear EDS1 precedes or coincides with the EDS1-dependent induction and repression of defense-related genes.