Tracing the origin and evolutionary history of plant nucleotide-binding site-leucine-rich repeat (NBS-LRR) genes.
Plant disease resistance genes (R genes) encode proteins that function to monitor signals indicating pathogenic infection, thus playing a critical role in the plant's defense system. Although many studies have been performed to explore the functional details of these important genes, their origin and evolutionary history remain unclear. In this study, focusing on the largest group of R genes, the nucleotide-binding site-leucine-rich repeat (NBS-LRR) genes, we conducted an extensive genome-wide survey of 38 representative model organisms and obtained insights into the evolutionary stage and timing of NBS-LRR genes. Our data show that the two major domains, NBS and LRR, existed before the split of prokaryotes and eukaryotes but their fusion was observed only in land plant lineages. The Toll/interleukin-1 receptor (TIR) class of NBS-LRR genes probably had an earlier origin than its nonTIR counterpart. The similarities of the innate immune systems of plants and animals are likely to have been shaped by convergent evolution after their independent origins. Our findings start to unravel the evolutionary history of these important genes from the perspective of comparative genomics and also highlight the important role of reorganizing pre-existing building blocks in generating evolutionary novelties.
State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.|Department of Ecology and Evolutionary Biology, Rice University, Houston, TX 77005, USA.
Jia-Xing
JX
Yue
Department of Plant and Soil Sciences, and Delaware Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.
Blake C
BC
Meyers
State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.
Jian-Qun
JQ
Chen
State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.
Dacheng
D
Tian
State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.
Sihai
S
Yang
D000595:Amino Acid Sequence; D000818:Animals; D060467:Disease Resistance / Q000235:genetics*; D019143:Evolution, Molecular; D000090263:Leucine-Rich Repeat Proteins; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics; D010944:Plants / Q000235:genetics*; D017434:Protein Structure, Tertiary / Q000235:genetics; D011506:Proteins / Q000235:genetics*; D017472:Receptors, Interleukin-1 / Q000235:genetics; D020449:Repetitive Sequences, Amino Acid
D000090263:Leucine-Rich Repeat Proteins; D011506:Proteins; D017472:Receptors, Interleukin-1