The Chloroplast Genome Sequencing And Phylogenetic Studies Of Eleutherococcus Plants

The plant of the genus Eleutherococcus,which belongs to the family Acanthopanaceae,is a small tree or deciduous shrub.There are currently 3 7 species of Eleutherococcus plants found worldwide,widely distributed in China,Japan,South Korea,eastern Russia,and other parts of East Asia and Northeast Asia.In recent years,Eleutherococcus plants have also been found in Southeast Asian countries and regions such as India,Bhutan,Mongolia,Nepal,the Philippines,Thailand,and Vietnam.Eleutherococcus plants generally have high medicinal value,such as anti fatigue,anti-inflammatory,anti stress,anti ulcer,and cardiovascular functions.To date,it has been reported that the cortex of Eleutherococcus plants has anti-inflammatory and potential anti-tumor activities,as well as therapeutic effects on bone diseases.However,Eleutherococcus plants do not have good morphological differentiation.And the existing universal DNA barcode has the problem of low identification efficiency.This article will study the complete chloroplast genomes of some Eleutherococcus plants that can be collected in order to better improve the efficiency of species identification.The complete genome sequence of chloroplasts is highly conserved and has a low base substitution rate.In this study,we assembled and annotated the complete chloroplast genomes of a total of9 samples from 7 species of Eleutherococcus plants that can be collected.They are: three different species of Eleutherococcus sessiliflorus,Eleutherococcus eleutherstylus,Eleutherococcus rubra,Eleutherococcus senticosus,Eleutherococcus scabra,Eleutherococcus tenuifolia,and Eleutherococcus longipedunculus.These chloroplast genomic data have now been uploaded to the National Center for Biotechnology Information(NCBI)of the United States.The main research results in this article are as follows:1.Assembled and annotated the chloroplast genomes of 9 samples from 7 species of Eleutherococcus plants.It was found that the chloroplast genome has a very typical tetrad structure,which includes LSC region,SSC region,and a pair of isolated IR regions.The chloroplast genome of Eleutherococcus plants has a sequence length of 155803-157328 bp,and the number of annotated genes ranges from 131 to 134.2.There are certain differences in the analysis of chloroplast genome sequences of Eleutherococcus plants.The difference in the number of genes encoded in chloroplast genomes among different species is mainly due to the difference in the number of protein encoded genes.Among the three genes encoded,the number of r RNA genes is the most conservative among different species.The basic GC content analysis showed that the GC content of chloroplast genomes of different Eleutherococcus species ranged from 3 7.9 3 % to37.99%,with no significant difference.3.The IR region of the chloroplast genome of Eleutherococcus plants has significant expansion and contraction,and there are slight differences between species at the boundary between the IR region and the LSC/SSC region.No ndf H gene was found in the three Eleutherococcus sessile strains at the boundary of JSB.The length of the ycl gene seems to affect the total length of the chloroplast genome.4.The chloroplast genomes of Eleutherococcus plants have many highly variable sites among themselves,and there are more than 2 5 0 mutation sites in the ycfl gene,which has a strong potential to become interspecific or even intraspecific DNA barcodes.5.From a phylogenetic perspective,Eleutherococcus plants have relatively close relationships,and their chloroplast genomes are classified into the same branch under the ML tree,which is different from other genera of Eleutherococcus plants.Currently,there is relatively little work on chloroplast genome sequencing in Eleutherococcus plants.In this study,the chloroplast genomes of nine Eleutherococcus plants were sequenced and their structural characteristics were analyzed.Through chloroplast genome detection,the Eleutherococcus plants were completely identified,providing a data basis for species identification and systematic research of Eleutherococcus plants.