The whole chloroplast genome of Mesua ferrea: Insight into the dynamic pattern of evolution and its comparison with species from recently diverged families

Abstract

Mesua ferrea is an important source of timber, oil and herbal medicines. In the present investigation, we assembled the whole chloroplast genome of M. ferrea of size 161.4 kb. The genome contained 86 protein-coding genes, 38 tRNAs, 8 rRNA genes and exhibited a characteristic quadripartite structural orientation, with two inverted repeats (27,614 bp) separated by an LSC (88,746 bp) region and an SSC (27,614 bp) (17,470 bp). Interestingly, no gene loss was identified in the M. ferrea genome, contrary to what has been observed in other Clusioid species. We compared the chloroplast genome of M. ferrea with the chloroplast genome of Bonnetia and Garcinia belonging to Bonnetiaceae and Clusiaceae families. Overall, the compared genomes possess a similar synteny of gene order except for a small inversion in Garcinia species. M. ferrea has the largest chloroplast genome size in Clusioid clade owing to the lengthening of the LSC, IR, and non-coding regions. Substantial differences were observed in population of simple sequence repeats (SSRs) and RNA editing sites among the studied genomes. A comparative assessment of chloroplast genomes revealed five highly divergence regions: rpl32, trnS-GCU_trnG-UCC, petN-psbM, psbZ_trnG-GCC and ccsA_ndhD among the analyzed sequences. Phylogenetic analyses and sequence homology search indicate that M. ferrea is closely related to the Garcinia species.