Comparative analysis, diversification, and functional validation of plant nucleotide-binding site domain genes

Area of Science:

• Plant genetics and genomics
• Molecular plant pathology
• Evolutionary biology

Background:

• Nucleotide-binding site (NBS) domain genes are crucial components of plant resistance (R) gene superfamily, mediating responses to pathogen attacks.
• Understanding NBS gene diversity and function is vital for crop improvement and disease resistance.

Purpose of the Study:

• To comprehensively identify and classify NBS-domain-containing genes across a wide range of plant species.
• To investigate the structural diversity, evolutionary patterns, and functional roles of NBS genes, particularly in relation to plant-pathogen interactions.

Main Methods:

• Bioinformatic analysis to identify and classify 12,820 NBS genes from 34 plant species.
• Phylogenetic analysis to determine orthogroups and evolutionary relationships.
• Gene expression profiling under various stress conditions.
• Genetic variation analysis between susceptible and tolerant cotton accessions.
• Virus-induced gene silencing (VIGS) to assess gene function in disease resistance.

Main Results:

• Discovery of 12,820 NBS genes across 34 species, classified into 168 classes with novel domain architectures.
• Identification of 603 orthogroups, including core and species-specific groups, with evidence of tandem duplications.
• Expression profiling revealed upregulation of specific NBS orthogroups (OG2, OG6, OG15) under stress conditions.
• Significant genetic variations were found in NBS genes between susceptible and tolerant cotton varieties.
• Functional validation using VIGS confirmed the role of GaNBS (OG2) in conferring resistance to cotton leaf curl disease.

Conclusions:

• The study provides a comprehensive catalog of plant NBS genes, highlighting their structural and evolutionary diversity.
• NBS genes, particularly specific orthogroups, are implicated in plant stress responses and disease resistance mechanisms.
• The findings offer valuable insights into plant adaptation and provide a foundation for developing disease-resistant crops.