Characterisation of the complete chloroplast genome of an endemic herb plant species, Rheum palmatum (Polygonaceae) in China

Rheum palmatum has a long history in medicine, which is one of the main export medicinal herb in China. The complete chloroplast genome of R. palmatum was assembled and reported in this study. The R. palmatum chloroplast genome was 161,541 bp in length as the circular and consisted a large single-copy (LSC) region of 86,519 bp, a small single-copy (SSC) region of 13,112 bp and a pair of inverted-repeat (IR) regions of 30,955 bp. The nucleotide composition was asymmetric 31.2% A (Adenine), 31.5% T (Thymine), 19.0% C (Cytosine), and 18.3% G (Guanine) with an overall G + C content of 37.3%. It encoded 131 genes, including 86 protein-coding genes (76 PCG species), 37 transfer RNA genes (26 tRNAs species), and eight ribosomal RNA genes (four rRNAs species). The Phylogenetic relationships used neighbour-joining (NJ) method and the result showed that R. palmatum and Rheum officinale are phylogenetically related to each other in the family Polygonaceae. This study will be very important for Chinese medicinal herb research value and clinical drug development for future in China.