Species-specific Duplications of NBS-encoding Genes in Chinese Chestnut (Castanea Mollissima)
Affiliations
The disease resistance (R) genes play an important role in protecting plants from infection by diverse pathogens in the environment. The nucleotide-binding site (NBS)-leucine-rich repeat (LRR) class of genes is one of the largest R gene families. Chinese chestnut (Castanea mollissima) is resistant to Chestnut Blight Disease, but relatively little is known about the resistance mechanism. We identified 519 NBS-encoding genes, including 374 NBS-LRR genes and 145 NBS-only genes. The majority of Ka/Ks were less than 1, suggesting the purifying selection operated during the evolutionary history of NBS-encoding genes. A minority (4/34) of Ka/Ks in non-TIR gene families were greater than 1, showing that some genes were under positive selection pressure. Furthermore, Ks peaked at a range of 0.4 to 0.5, indicating that ancient duplications arose during the evolution. The relationship between Ka/Ks and Ks indicated greater selective pressure on the newer and older genes with the critical value of Ks = 0.4-0.5. Notably, species-specific duplications were detected in NBS-encoding genes. In addition, the group of RPW8-NBS-encoding genes clustered together as an independent clade located at a relatively basal position in the phylogenetic tree. Many cis-acting elements related to plant defense responses were detected in promoters of NBS-encoding genes.
Bae S, Zoclanclounon Y, Park G, Lee J, Kim T Genes (Basel). 2025; 16(2).
PMID: 40004529 PMC: 11855831. DOI: 10.3390/genes16020200.
Mao B, Shen M, Fu Y, Wang J, Yu P, Xiao Y PLoS One. 2024; 19(12):e0310509.
PMID: 39666625 PMC: 11637356. DOI: 10.1371/journal.pone.0310509.
Segmental and Tandem Duplications Driving the Recent Gene Expansion in the Asparagus Genome.
Die J, Castro P, Millan T, Gil J Genes (Basel). 2018; 9(12).
PMID: 30477134 PMC: 6316259. DOI: 10.3390/genes9120568.
Genome-scale examination of NBS-encoding genes in blueberry.
Die J, Roman B, Qi X, Rowland L Sci Rep. 2018; 8(1):3429.
PMID: 29467425 PMC: 5821885. DOI: 10.1038/s41598-018-21738-7.
Zhong Y, Zhang X, Cheng Z BMC Genomics. 2018; 19(1):128.
PMID: 29422035 PMC: 5806312. DOI: 10.1186/s12864-018-4521-4.