Journal Article

Comparative root transcriptome of wild Arachis reveals NBS-LRR genes related to nematode resistance

Mota, Ana Paula Zotta, Araujo, Ana Claudia Guerra, Guimaraes, Patricia Messenberg, Vidigal, Bruna, Leal-Bertioli, Soraya C. M., Togawa, Roberto Coiti, Bertioli, David John, Danchin, Etienne G. J., Brasileiro, Ana Cristina Miranda

2018

Overview

Background The Root-Knot Nematode (RKN), Meloidogyne arenaria , significantly reduces peanut grain quality and yield worldwide. Whilst the cultivated species has low levels of resistance to RKN and other pests and diseases, peanut wild relatives ( Arachis spp.) show rich genetic diversity and harbor high levels of resistance to many pathogens and environmental constraints. Comparative transcriptome analysis can be applied to identify candidate resistance genes. Results Transcriptome analysis during the early stages of RKN infection of two peanut wild relatives, the highly RKN resistant Arachis stenosperma and the moderately susceptible A. duranensis , revealed genes related to plant immunity with contrasting expression profiles. These included genes involved in hormone signaling and secondary metabolites production and also members of the NBS-LRR class of plant disease resistance (R) genes. From 345 NBS-LRRs identified in A.duranensis reference genome, 52 were differentially expressed between inoculated and control samples, with the majority occurring in physical clusters unevenly distributed on eight chromosomes with preferential tandem duplication. The majority of these NBS-LRR genes showed contrasting expression behaviour between A. duranensis and A. stenosperma , particularly at 6 days after nematode inoculation, coinciding with the onset of the Hypersensitive Response in the resistant species. The physical clustering of some of these NBS-LRR genes correlated with their expression patterns in the contrasting genotypes. Four NBS-LRR genes exclusively expressed in A. stenosperma are located within clusters on chromosome Aradu. A09, which harbors a QTL for RKN resistance, suggesting a functional role for their physical arrangement and their potential involvement in this defense response. Conclusion The identification of functional novel R genes in wild Arachis species responsible for triggering effective defense cascades can contribute to the crop genetic improvement and enhance peanut resilience to RKN.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Agriculture / Analysis / Animals / Arachis / Arachis - genetics / Arachis - metabolism / Arachis - parasitology / Binding sites / Biodiversity / Biomedical and Life Sciences / Cascades / Chromosomes / Clustering / Disease resistance / Disease Resistance - genetics / Environmental Sciences / Gene expression / Gene Expression Profiling / gene expression regulation / Genes / Genes, Plant - genetics / Genes, Plant - physiology / Genetic diversity / Genetic improvement / genetic variation / Genomes / Genomics / genotype / Genotypes / grain quality / Hypersensitive response / Identification / Immunity / Infections / Inoculation / Legumes / Life Sciences / Meloidogyne / Meloidogyne arenaria / Metabolites / NBS-LRR gene / Nematodes / pathogens / peanut / Peanuts / Pests / Phylogeny / Physical arrangement / plant disease resistance / Plant diseases / Plant Diseases - immunology / Plant Diseases - parasitology / plant diseases and disorders / Plant genetics / Plant immunity / Plant Roots - genetics / Plant Roots - metabolism / Plant Roots - parasitology / Plant Sciences / Plant-abiotic interactions / Quantitative trait loci / Real-Time Polymerase Chain Reaction / Research Article / resistance genes / Root knot / Root Knot Nematode / root-knot nematodes / Roundworm infections / Secondary metabolites / Transcriptome / transcriptomics / Tree Biology / Trends / Tylenchoidea / wild relatives