Chinese Bulletin of Botany ›› 2020, Vol. 55 ›› Issue (4): 442-456.DOI: 10.11983/CBB19157

• EXPERIMENTAL COMMUNICATIONS • Previous Articles     Next Articles

Identification and Evolution of LRR VIII-2 Subfamily Genes in Four Model Plant Species

Chenyang Yan1,2,Yingnan Chen1,2,*()   

  1. 1Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing 210037, China
    2Co-Innovation Center for the Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China
  • Received:2019-08-16 Accepted:2020-03-23 Online:2020-07-01 Published:2020-05-21
  • Contact: Yingnan Chen

Abstract: Whole-genome duplication and tandem duplication are two important mechanisms for gene duplication, which play important roles in promoting the genomic and genetic diversity. In Arabidopsis, AtLRR-RLK encodes receptor-like kinases rich in leucine repeats, which is a multi-gene family arising from large-scale gene expansion during angiosperm evolution. It is composed of 15 subfamilies, among which, AtLRR VIII-2 is the subfamily with the highest proportion of tandem repeats. In this study, we use the genes in LRR VIII-2 as an example to analyze the gene expansion and differential retention in four model plants (Arabidopsis thaliana, Populus trichocarpa, Vitis vinifera and Carica papaya). Results showed that paralogous gene pairs were identified in the LRR VIII-2 subfamily in Arabidopsis, poplar and grape, while no such pair was found in papaya. The LRR VIII-2 subfamily expanded the most significantly in poplar and moderately expanded in Arabidopsis and grape, but some genes of the LRR VIII-2 subfamily in papaya have been lost. In addition, the paralogous and orthologous genes in the LRR VIII-2 subfamily were under strong purifying selection in the four investigated plant species, except for a pair of paralogous genes in poplar. An in-depth phylogenetic analysis of the LRR VIII-2 subfamily helps to understand the role and significance of gene duplication in plant evolution, and provides useful information for predicting the function of homologous gene among different species. This analytical pipeline is also applicable for deciphering the evolution history of other gene families.

Key words: receptor-like protein kinases, leucine-rich repeats, whole-genome duplication, tandem duplication