AUTHOR=Guo Shuai , Liao Xuejiao , Chen Shiyu , Liao Baosheng , Guo Yiming , Cheng Ruiyang , Xiao Shuiming , Hu Haoyu , Chen Jun , Pei Jin , Chen Yangjin , Xu Jiang , Chen Shilin 

TITLE=A Comparative Analysis of the Chloroplast Genomes of Four Polygonum Medicinal Plants

JOURNAL=Frontiers in Genetics

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.764534

DOI=10.3389/fgene.2022.764534

ISSN=1664-8021

ABSTRACT=<p><italic>Polygonum</italic> is a generalized genus of the Polygonaceae family that includes various herbaceous plants. In order to provide aid in understanding the evolutionary and phylogenetic relationship in <italic>Polygonum</italic> at the chloroplast (cp) genome-scale level, we sequenced and annotated the complete chloroplast genomes of four <italic>Polygonum</italic> species using next-generation sequencing technology and CpGAVAS. Then, repeat sequences, IR contractions, and expansion and transformation sites of chloroplast genomes of four <italic>Polygonum</italic> species were studied, and a phylogenetic tree was built using the chloroplast genomes of <italic>Polygonum</italic>. The results indicated that the chloroplast genome construction of <italic>Polygonum</italic> also displayed characteristic four types of results, comparable to the published chloroplast genome of recorded angiosperms. The chloroplast genomes of the four <italic>Polygonum</italic> plants are highly consistent in genome size (159,015 bp–163,461 bp), number of genes (112 genes, including 78 protein-coding genes, 30 tRNA genes, and 4 rRNA genes), gene types, gene order, codon usage, and repeat sequence distribution, which identifies the high preservation among the <italic>Polygonum</italic> chloroplast genomes. The <italic>Polygonum</italic> phylogenetic tree was recreated by a full sequence of the chloroplast genome, which illustrates that the <italic>P. bistorta</italic>, <italic>P. orientale</italic>, and <italic>P. perfoliatum</italic> are divided into the same branch, and <italic>P. aviculare</italic> belongs to <italic>Fallopia</italic>. The precise system site of lots base parts requires further verification, but the study would provide a basis for developing the available genetic resources and evolutionary relationships of <italic>Polygonum</italic>.</p>