Complete Chloroplast Genome Sequence of and Characterization of Chloroplast Regulatory Elements

is a famous medicinal plant. However, the limited chloroplast genome information of , especially for the chloroplast DNA sequence resources, has hindered the study of chloroplast genome transformation. Here, the complete chloroplast (cp) genome of was reported. This genome was 152,164bp in length, included 37.2% GC content and was structurally arranged into two 24,699bp inverted repeats (IRs) and two single-copy areas. The sizes of the large single-copy region and the small single-copy region were 84,657 and 18,109bp, respectively. The cp genome consisted of 127 coding genes, including 83 protein coding genes, 36 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. For those genes, 95 genes were single copy genes and 16 genes were duplicated in two inverted regions with seven tRNAs, four rRNAs, and five protein coding genes. Then, genomic DNA of was used as a template, and the endogenous 5' and 3' flanking sequences of the gene and gene were selected as homologous recombinant fragments in vector construction and cloned through PCR. The endogenous 5' flanking sequences of the gene and gene, the endogenous 3' flanking sequences of the gene, gene, and gene and one sequence element from the psbN-psbH chloroplast operon were cloned, and certain chloroplast regulatory elements were identified. Two homologous recombination fragments and all of these elements were constructed into the cloning vector pBluescript SK (+) to yield a series of chloroplast expression vectors, which harbored the reporter gene and the selectable marker gene. After identification, the chloroplast expression vectors were transformed into and the function of predicted regulatory elements was confirmed by a spectinomycin resistance test and fluorescence intensity measurement. The results indicated that gene and gene were efficiently expressed under the regulation of predicted regulatory elements and the chloroplast expression vector had been successfully constructed, thereby providing a solid foundation for establishing subsequent chloroplast transformation system and genetic improvement of .