Divergent evolution of multiple virus‐resistance genes from a progenitor in Capsicum spp.

Abstract

SummaryPlants have evolved hundreds of nucleotide-binding and leucine-rich domain proteins (NLRs) as potential intracellular immune receptors, but the evolutionary mechanism leading to the ability to recognize specific pathogen effectors is elusive.Here, we cloned Pvr4 (a Potyvirus resistance gene in Capsicum annuum) and Tsw (a Tomato spotted wilt virus resistance gene in Capsicum chinense) via a genome-based approach using independent segregating populations.The genes both encode typical NLRs and are located at the same locus on pepper chromosome 10. Despite the fact that these two genes recognize completely different viral effectors, the genomic structures and coding sequences of the two genes are strikingly similar. Phylogenetic studies revealed that these two immune receptors diverged from a progenitor gene of a common ancestor.Our results suggest that sequence variations caused by gene duplication and neofunctionalization may underlie the evolution of the ability to specifically recognize different effectors. These findings thereby provide insight into the divergent evolution of plant immune receptors.

Identification and characterization of a new class of Tomato spotted wilt virus isolates that break Tsw‐based resistance in a temperature‐dependent manner

“…The Sw-5b gene has been cloned and encodes a coiled-coil, nucleotide-binding, leucine-rich repeat domain (CC-NB-LRR) protein that is triggered by the TSWV cell-to-cell movement protein (NSm; Spassova et al, 2001;Hallwass et al, 2014;Peiro et al, 2014). The Tsw gene has been cloned very recently and also encodes a CC-NB-LRR protein that in this case is being triggered by the NSs RNA silencing suppressor (RSS) protein (de Ronde et al, 2013;Hedil & Kormelink, 2016;Kim et al, 2017). Although initial studies indicated that NSs proteins from natural resistance-breaking isolates of TSWV have lost avirulence and RSS activity (de Ronde et al, 2013), triggering of Tsw-based resistance in Capsicum does not require a functional RSS, as shown by a recent screen of NSs alanine substitution mutants (de Ronde et al, 2014).…”

Isolation, characterization and genetic diversity of NBS-LRR class disease-resistant gene analogs in multiple virus resistant line of chilli (Capsicum annuum L.)

“…This suggests the presence of Pvr9 gene for poty virus resistance in the 'IHR2451' genotype. Recently Kim et al (2016) reported that Pvr4 (a poty virus resistant gene in C. annuum) and Tsw (Tomato spotted wilt virus resistant gene in C. chinense) encode for nucleotide binding and leucine rich repeat domain proteins and these multiple virus resistant genes diverged from a progenitor gene of a common ancestor in Capsicum spp. as indicated by genomic structure and coding sequences of these two genes.…”

Genome-wide functional analysis of hot pepper immune receptors reveals an autonomous NLR cluster in seed plants

“…These genes are genetically linked 34 and oriented head-to-head so that they may share a promoter for simultaneous regulation of 35 transcription. Although in silico analyses revealed that NLRs with integrated domains are 36 common in higher plants, functional NLR pairs have been discovered in only a few plant 37 species (15). A more complex NLR model was reported as an 'NLR network', primarily in 38 Solanaceous plants.…”