Genome Wide Analysis of Nucleotide-Binding Site Disease Resistance Genes in Brachypodium distachyon

Abstract EN

Nucleotide-binding site (NBS) disease resistance genes play an important role in defending plants from a variety of pathogens and insect pests.

Many R-genes have been identified in various plant species.

However, little is known about the NBS-encoding genes in Brachypodium distachyon.

In this study, using computational analysis of the B.

distachyon genome, we identified 126 regular NBS-encoding genes and characterized them on the bases of structural diversity, conserved protein motifs, chromosomal locations, gene duplications, promoter region, and phylogenetic relationships.

EST hits and full-length cDNA sequences (from Brachypodium database) of 126 R-like candidates supported their existence.

Based on the occurrence of conserved protein motifs such as coiled-coil (CC), NBS, leucine-rich repeat (LRR), these regular NBS-LRR genes were classified into four subgroups: CC-NBS-LRR, NBS-LRR, CC-NBS, and X-NBS.

Further expression analysis of the regular NBS-encoding genes in Brachypodium database revealed that these genes are expressed in a wide range of libraries, including those constructed from various developmental stages, tissue types, and drought challenged or nonchallenged tissue.