Journal Article

Engineering Resistance against Sclerotinia sclerotiorum Using a Truncated NLR (TNx) and a Defense-Priming Gene

Ferreira, Deziany da Silva, Mota, Ana Paula Zotta, Pereira, Bruna Medeiros, de Araújo, Ana Claudia Guerra, Guimaraes, Patricia Messenberg, Berbert, Pedro Souza, de Aguiar, Matheus Nascimento, Quintana, Andressa Cunha, Brasileiro, Ana Cristina Miranda

2022

Overview

The association of both cell-surface PRRs (Pattern Recognition Receptors) and intracellular receptor NLRs (Nucleotide-Binding Leucine-Rich Repeat) in engineered plants have the potential to activate strong defenses against a broad range of pathogens. Here, we describe the identification, characterization, and in planta functional analysis of a novel truncated NLR (TNx) gene from the wild species Arachis stenosperma (AsTIR19), with a protein structure lacking the C-terminal LRR (Leucine Rich Repeat) domain involved in pathogen perception. Overexpression of AsTIR19 in tobacco plants led to a significant reduction in infection caused by Sclerotinia sclerotiorum, with a further reduction in pyramid lines containing an expansin-like B gene (AdEXLB8) potentially involved in defense priming. Transcription analysis of tobacco transgenic lines revealed induction of hormone defense pathways (SA; JA-ET) and PRs (Pathogenesis-Related proteins) production. The strong upregulation of the respiratory burst oxidase homolog D (RbohD) gene in the pyramid lines suggests its central role in mediating immune responses in plants co-expressing the two transgenes, with reactive oxygen species (ROS) production enhanced by AdEXLB8 cues leading to stronger defense response. Here, we demonstrate that the association of potential priming elicitors and truncated NLRs can produce a synergistic effect on fungal resistance, constituting a promising strategy for improved, non-specific resistance to plant pathogens.

• Publisher: MDPI AG,MDPI
• Subject: Abiotic stress / Apoptosis / Arachis / Cell surface / Chromosomes / expansins / Functional analysis / Fungi / gene pyramid / Genes / Genetic engineering / genetically modified organisms / Genetics / Genomes / Immune response / immunity / Leucine / Life Sciences / Nucleotides / oxidoreductases / Pathogenesis / Pathogenesis-related proteins / Pathogens / Pattern recognition / Pattern recognition receptors / Plant resistance / Plants genetics / Priming / Protein structure / Proteins / Reactive oxygen species / Receptors / Reduction / respiratory burst / Respiratory burst oxidase / Roles / Sclerotinia sclerotiorum / synergism / Synergistic effect / TIR-NLR / Tobacco / Transgenes / Transgenic plants / Virulence / white mold / wild Arachis