Panax vietnamensis Ha et Grushv., naturally distributed in Ngoc Linh Mountain, is an endemic Panax species of Vietnam. For centuries, P. vietnamensis has been used in traditional folk medicine to treat many serious diseases or enhance physical strength. Ginsenosides are responsible for most of the medicinal effects of the Panax species. Acetoacetyl-CoA thiolase (AACT) is considered as an important enzyme involved in the biosynthesis of ginsenoside. In this study, a full-length cDNA of the gene encoding AACT protein (GeneBank accession number MZ272018) was obtained from P. vietnamensis using reverse transcription PCR. The gene open reading frame (1224 bp) encodes 408 amino acids. This cDNA sequence is 99.08% similar to the cDNA sequence of Panax notoginseng (KJ804173.1). The functional analysis of its protein by InterPro showed that the structure of AACT monomer consists of three domains, including thiolase-like domain (17-285), N-terminal (18-276), and C-terminal (286-406). Although there were some differences in the nucleotide sequence of the AACT cDNA gene between P. vietnamensis and the reference species, all important domains and sites related to the thiolase activity were observed. Phylogenetic analysis using AACT cDNA gene sequence revealed a close relationship of P. vietnamensis with P. notoginseng and Trachyspemum ammi. The quantitative real-time PCR results indicated the expression of AACT gene of P. vietnamensis depended on types of tissue and plant developmental stages (1, 4, 6 and 11 years old). The gene was expressed at higher levels in roots than in leaves and the highest expression of AACT gene was detected in the 11-year-old roots. The results provided valuable information for further studies on the biosynthesis of ginsenoside in P. vietnamensis in particular and Panax species in general.

C-repeat binding factor (CBF) proteins are transcription factors involved in plant response to abiotic stresses, especially low-temperature condition. In this research, a CBF3-coding gene was isolated from a cold-acclimation maize variety, Zea mays var. Tevang-1 and denoted as ZmCBF3tv. The isolated gene shared 96.49% homology with the B73-reference gene and had no intron in the coding sequence. By using bioinformatic tools, a number of variations in the nucleotide and amino acid sequences were identified. An alignment between ZmCBF3tv and other CBF/DREB1 proteins from various species revealed functional regions and typical features, such as nuclear localization signal (NLS), the AP2 DNA-binding domain, and acidic-amino-acid-rich segments. Additionally, a phylogenetic analysis based on the AP2 domain showed that the maize CBF3 transcription factor had the highest similarity with that from rice and closely related to other DREB1/CBF protein of monocots. The function of the ZmCBF3tv product is suggested to be a CBF/DREB1 transcription factor.

Panax vietnamensis Ha et Grushv. is a species of the genus Panax native to Central Vietnam, containing a family of triterpene saponins named ginsenosides. This group of biomolecules possesses valuable therapeutic properties against cancer, hepatitis, diabetes, inflammation as well as stress and anxiety. Farnesyl diphosphate synthase (FPS) is a key enzyme participating in the ginsenoside biosynthesis pathway. In this study, a FPS gene from P. vietnamensis (PvFPS) was isolated and characterized. The PvFPS cDNA contained an open reading frame of 1032 bp, encoding a polypeptide chain of 342 amino acid residues. Nucleotide sequence comparison showed that FPS was highly conserved among most species, with two Aspartate-rich motifs responsible for product chain length determination strongly sustained. PvFPS was closely related to those of the same genera and order and differed from those from other kingdoms. PvFPS expression was detected at a greater level in root tissues than in leaves in all ages. Our findings provided information concerning the properties of a crucial gene in the ginsenoside biosynthesis, thus enhancing our understanding of this important pathway.

Genetic diversity plays an important role in diversity conservation at multiple levels and supports to monitor and assess genetic variation. In plants, genetic diversity provides the ability to adapt and respond to environmental conditions that helps plants to survive through changing environments. Genetic diversity analyses based on molecular genetic markers are effective tools for conservation and reintroduction of rare and endangered species. In recent years, the development of various chemical and molecular techniques for studying genetic diversity has received great attention. While biochemical markers are primarily used in the diagnosis of pathogens, DNA markers have been developed and widely applied for identification of species and population based on the genotype of an organism that is more stable and not easily affected by the environmental factors. PCR-based molecular marker tools, such as restriction fragment length polymorphisms (RFLPs), random amplified polymorphic DNA (RAPD), simple sequence repeats (SSRs) are used for analysing the difference in the targeted DNA sequences. With the rapid and robust development of genomic sequencing technology it is now possible to obtain and analyse DNA sequences of the whole genome of studied organisms. However, each type of DNA markers has different principles, as well as the pros and cons of specificity. In this article, we review methods and point out DNA markers, which are considered as reliable and widely used tools for the detection of genetic variation. In addition, we present the application of DNA marker in analysing genetic diversity of wild, domestic and medicinal plants, as well as some perspectives on the future of DNA marker’s application in the analysis of genetic diversity.

C-repeat binding factor (CBF) proteins are transcription factors involved in plant response to abiotic stresses, especially low-temperature condition. In this research, a CBF3-coding gene was isolated from a cold-acclimation maize variety, Zea mays var. Tevang-1 and denoted as ZmCBF3tv. The isolated gene shared 96.49% homology with the B73-reference gene and had no intron in the coding sequence. By using bioinformatic tools, a number of variations in the nucleotide and amino acid sequences were identified. An alignment between ZmCBF3tv and other CBF/DREB1 proteins from various species revealed functional regions and typical features, such as nuclear localization signal (NLS), the AP2 DNA-binding domain, and acidic-amino-acid-rich segments. Additionally, a phylogenetic analysis based on the AP2 domain showed that the maize CBF3 transcription factor had the highest similarity with that from rice and closely related to other DREB1/CBF protein of monocots. The function of the ZmCBF3tv product is suggested to be a CBF/DREB1 transcription factor.