Inferring RPW8-NLRs's evolution patterns in seed plants: case study in Vitis vinifera

Area of Science:

• Plant molecular biology
• Genomics
• Evolutionary biology

Background:

• The RNL (RPW8-NLR) gene family encodes nucleotide oligomerization domain (NOD)-like receptors involved in plant disease resistance.
• While RNLs like NRG1 and ADR1 are known, their evolutionary history in higher plants remains largely unexplored.
• Understanding RNL diversity is key to plant immunity.

Purpose of the Study:

• To trace the evolutionary diversification of the RNL gene subfamily across plant species.
• To investigate the structural and evolutionary variability of RNLs in different grapevine (Vitis vinifera) genomes.
• To explore RNL gene expression patterns in response to powdery mildew infection in grapevies.

Main Methods:

• Comparative genomic analysis of 73 plant genomes to identify RNL gene family expansion and diversification.
• Phylogenetic analysis of RNL proteins from six grapevine varieties, including a reference genome.
• Transcriptomic profiling using qRT-PCR and public databases to analyze RNL expression in response to powdery mildew.

Main Results:

• Significant diversification and expansion of the RNL gene family were observed across plant species and within grapevine varieties.
• The number of RNL genes varied notably among the analyzed grapevine genomes, ranging from 6 to 14.
• Phylogenetic analysis revealed that grapevine RNLs predominantly cluster within the NRG1 clade.
• Transcriptomic data indicated variability in RNL expression, suggesting functional expansion/contraction in grapevine.

Conclusions:

• The RNL gene family exhibits substantial evolutionary diversification and expansion in plants, particularly in grapevine.
• Variability in RNL copy number and expression in grapevies suggests a dynamic role in plant immunity.
• Identified RNLs serve as potential candidates for future functional studies on grape immune signaling pathways.