title: Duplication and Divergence of Leucine-Rich Repeat Receptor-Like Protein Kinase (LRR-RLK) Genes in Basal AngiospermAmborella trichopoda.
abstract: Leucine-rich repeat receptor-like protein kinases (LRR-RLKs) are the largest group of receptor-like kinases, which are one of the largest protein superfamilies in plants, and play crucial roles in development and stress responses. Although the evolution ofLRR-RLKfamilies has been investigated in some eudicot and monocot plants, no comprehensive evolutionary studies have been performed for these genes in basal angiosperms likeAmborella trichopoda. In this study, we identified 94LRR-RLKgenes in the genome ofA. trichopoda. The number ofLRR-RLKgenes in the genome ofA. trichopodais only 17-50% of that of several eudicot and monocot species. Tandem duplication and whole-genome duplication have made limited contributions to the expansion ofLRR-RLKgenes inA. trichopoda. According to the phylogenetic analysis, allA. trichopoda LRR-RLKgenes can be organized into 18 subfamilies, which roughly correspond to theLRR-RLKsubfamilies defined inArabidopsis thaliana. MostLRR-RLKsubfamilies are characterized by highly conserved protein structures, motif compositions, and gene structures. The unique gene structure, protein structures, and protein motif compositions of each subfamily provide evidence for functional divergence among LRR-RLK subfamilies. Moreover, the expression data ofLRR-RLKgenes provided further evidence for the functional diversification of them. In addition, selection analyses showed that most LRR-RLK protein sites are subject to purifying selection. Our results contribute to a better understanding of the evolution of LRR-RLK gene family in angiosperm and provide a framework for further functional investigation onA. trichopodaLRR-RLKs.
authors.affiliation: College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China.
authors.forename: Ping-Li
authors.initials: PL
authors.lastname: Liu
authors.affiliation: Department of Chinese Cabbage, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China.
authors.forename: Lu-Lu
authors.initials: LL
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences Beijing, China.
authors.forename: Peng-Wei
authors.initials: PW
authors.lastname: Li
authors.affiliation: College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China.
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Mao
authors.affiliation: College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China.
authors.forename: Shu-Min
authors.initials: SM
authors.lastname: Gao
authors.affiliation: College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China.
authors.forename: Peng-Hao
authors.initials: PH
authors.lastname: Shi
authors.affiliation: College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China.
authors.forename: Jun-Qing
authors.initials: JQ
authors.lastname: Gong
keywords: Amborella trichopoda; expression; functional divergence; gene structure; leucine-rich repeat receptor-like kinase (LRR-RLK); protein motif; protein structure