ABSTRACT
As two original plants of Tibetan herb Jieji, Gentiana waltonii Burk. and Gentiana lhassica Burk. belong to Section Cruciata of Gentiana, Gentianaceae. Here, we report on whole chloroplast genome sequences in the alpine species, respectively, and the features of plastomes were investigated. The plastome of G. waltonii is 148 705 bp long (148 652 bp in G. lhassica) and encodes 112 genes, including 78 protein-coding genes, 30 transfer RNA genes, and 4 ribosomal RNA genes. Two pseudogenes, namely ψrps16 and ψinfA, were found in plastomes. In addition, two novel loci were detected, and a species-specific polymerase chain reaction assay was developed for differentiating G. waltonii and G. lhassica from 10 alpine species in Section Cruciata. Gentiana. Our study provides basic data for identifying Tibetan herbs, alpine species conservation and molecular phylogenetic studies of Gentiana and Gentianaceae.
ABSTRACT
The roots and flowers of Gentiana waltonii and Gentiana robusta are used as Tibetan herb Jie-Ji in traditional Tibetan medicine, with iridoids as the main active ingredient and index components. To study the pathway of iridoid biosynthesis, roots, stems, leaves and flowers of G. waltonii and G. robusta were subjected to a high-throughput transcriptomic sequencing analysis by Illumina HiseqXTen. After removing insignificant reads and de novo splicing, 79 455 and 78 466 unigenes were obtained from G. waltonii and G. robusta respectively, with average length as 834 bp and 862 bp. The unigene GO functions could be divided into three categories of 65 branches. The unigenes were aligned in KOG database and were classified into 25 classes according to function. In KEGG database, 315 and 340 unigenes of G. waltonii and G. robusta were implicated in 20 standard secondary metabolic pathways, respectively. Furthermore, 80 and 57 unigenes of the two species were analyzed to encode 24 key enzymes in the pathway related to iridoid biosynthesis. There were differences in gene expression among different organs. Based on sequence data, significant amounts of SSRs, SNPs and InDels were detected in each dataset. This study provides a platform for further development of molecular markers, excavation of functional genes, and research into metabolic pathways and their regulatory mechanism within G. waltonii and G. robusta.