RESUMEN
Amomi Fructus (Sharen, AF) is a traditional Chinese medicine (TCM) from three source species (or varieties), including Wurfbainia villosa var. villosa (WVV), W. villosa var. xanthioides (WVX), or W. longiligularis (WL). Among them, WVV has been transplanted from its top-geoherb region, Guangdong, to its current main production area, Yunnan, for >50 years in China. However, the genetic and transcriptomic differentiation among multiple AF source species (or varieties) and between the origin and transplanted populations of WVV is unknown. In our study, the observed overall higher expression of terpenoid biosynthesis genes in WVV than in WVX provided possible evidence for the better pharmacological effect of WVV. We also screened six candidate borneol dehydrogenases (BDHs) that potentially catalyzed borneol into camphor in WVV and functionally verified them. Highly expressed genes at the P2 stage of WVV, Wv05G1424 and Wv05G1438, were capable of catalyzing the formation of camphor from (+)-borneol, (-)-borneol and DL-isoborneol. Moreover, the BDH genes may experience independent evolution after acquiring the ancestral copies, and the following tandem duplications might account for the abundant camphor content in WVV. Furthermore, four populations of WVV, WVX, and WL are genetically differentiated, and the gene flow from WVX to WVV in Yunnan contributed to the greater genetic diversity in the introduced population (WVV-JH) than in its top-geoherb region (WVV-YC), which showed the lowest genetic diversity and might undergo genetic degradation. In addition, terpene synthesis (TPS) and BDH genes were selected among populations of multiple AF source species (or varieties) and between the top- and non-top-geoherb regions, which might explain the difference in metabolites between these populations. Our findings provide important guidance for the conservation, genetic improvement, and industrial development of the three source species (or varieties) and for identifying top-geoherbalism with molecular markers, and proper clinical application of AF.
RESUMEN
Wurfbainia neoaurantiaca is a medicinal plant endemic to Yunnan Province, China. In this study, its complete chloroplast genome was assembled and characterized. The total genome size of W. neoaurantiaca was 158,484 bp in length, consisting of a large single-copy region (LSC), a small single-copy region (SSC) and two inverted repeat regions (IRs) with 88,605 bp, 15,285 bp and 29,822 bp, respectively. Its GC content was 36.08%. The chloroplast genome encoded 113 unique genes, including 79 protein-coding, 30 tRNA, and four rRNA genes. The result of the phylogenetic analysis indicated that W. neoaurantiaca was related to W. villosa var. xanthioides and supported de Boer's classification that W. compacta, W. longiligularis, W. neoaurantiaca, W. villosa, W. villosa var. xanthioides and Amomum krervanh belonged to the Wurfbainia Clade.
RESUMEN
The genus Dracaena is the main source of dragon's blood, which is a plant resin and has been used as traditional medicine since ancient times in different civilizations. However, the chromosome numbers and karyotypes present in this genus remain poorly understood. In this study, fluorescence in situ hybridization (FISH) using oligonucleotide probes for ribosomal DNAs (5S and 45S rDNA) and telomeric repeats (TTTAGGG)3 was applied to analyze 4 related species: Dracaena terniflora Roxb., Dracaena cambodiana Pierre ex Gagnep., Aizong (Dracaena sp.), and Dracaena cochinchinensis (Lour.) S.C. Chen. In all 4 species, both 5S and 45S rDNA showed hybridization signals in the paracentromeric region of a pair of chromosomes; the sizes of the 45S rDNA signals were larger than those of the 5S rDNA. Importantly, the telomeric repeat signals were located in the telomeric regions of almost all chromosomes. The results indicated that the chromosome number of all 4 Dracaena species is 2n = 40, and the lengths of the mitotic metaphase chromosomes range from 0.99 to 2.98 µm. Our results provide useful cytogenetic information, which will be beneficial to future studies in genome structure of the genus Dracaena.