Interspecific variation and phylogenetic relationship between mangrove and non-mangrove species of a same family (Meliaceae)—insights from comparative analysis of complete chloroplast genome

PeerJ

article

Fengxiao Tan¹  Weixi Li²  Hui Feng²  Yelin Huang²  Achyut Kumar Banerjee² 

[1]College of Natural Resources and Environment, South China Agricultural University

[2]School of Life Sciences, Sun Yat-Sen University

关键词: Phylogenetics;    Mangroves;    Coastal ecosystem;    Chloroplast genome;    Population genetics;    Adaptation;    Stress response;   

DOI  :  10.7717/peerj.15527

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The mahogany family, Meliaceae, contains 58 genera with only one mangrove genus: Xylocarpus. Two of the three species of the genus Xylocarpus are true mangroves (X. granatum and X. moluccensis), and one is a non-mangrove (X. rumphii). In order to resolve the phylogenetic relationship between the mangrove and non-mangrove species, we sequenced chloroplast genomes of these Xylocarpus species along with two non-mangrove species of the Meliaceae family (Carapa guianensis and Swietenia macrophylla) and compared the genome features and variations across the five species.The five Meliaceae species shared 130 genes (85 protein-coding genes, 37 tRNA, and eight rRNA) with identical direction and order, with a few variations in genes and intergenic spacers. The repetitive sequences identified in the rpl22 gene region only occurred in Xylocarpus, while the repetitive sequences in accD were found in X. moluccensis and X. rumphii. The TrnH-GUG and rpl32 gene regions and four non-coding gene regions showed high variabilities between X. granatum and the two non-mangrove species (S. macrophylla and C. guianensis). In addition, among the Xylocarpus species, only two genes (accD and clpP) showed positive selection. Carapa guianensis and S. macrophylla owned unique RNA editing sites. The above genes played an important role in acclimation to different stress factors like heat, low temperature, high UV light, and high salinity. Phylogenetic analysis with 22 species in the order Sapindales supported previous studies, which revealed that the non-mangrove species X. rumphii is closer to X. moluccensis than X. granatum. Overall, our results provided important insights into the variation of genetic structure and adaptation mechanism at interspecific (three Xylocarpus species) and intergeneric (mangrove and non-mangrove genera) levels.

【 授权许可】

CC BY