Fusarium is the major pathogen of root rot of Pseudostellaria heterophylla. This study aims to explain the possible distribution of Fusarium species and the contamination of its toxin-chemotypes in tuberous root of P. heterophylla. A total of 89 strains of fungi were isolated from the tuberous root of P. heterophylla. Among them, 29 strains were identified as Fusarium by ITS2 sequence, accounting for 32.5%. They were identified as five species of F. avenaceum, F. tricinctum, F. fujikuroi, F. oxysporum, and F. graminearum based on β-Tubulin and EF-1α genes. LC-MS/MS detected 18, 1, and 5 strains able to produce ZEN, DON, and T2, which accounted for 62.1%, 3.4%, and 17.2%, respectively. Strain JK3-3 can produce ZEN, DON, and T2, while strains BH1-4-1, BH6-5, and BH16-2 can produce ZEN and T2. PCR detected six key synthase genes of Tri1, Tri7, Tri8, Tri13, PKS14, and PKS13 in strain JK3-3, which synthesized three toxins of ZEN, DON, and T2. Four key synthase genes of Tri8, Tri13, PKS14, and PKS13 were detected in strains BH1-4-1, BH6-5, and BH16-2, which were responsible for the synthesis of ZEN and T2. The results showed that the key genes of toxin biosynthesis were highly correlated with the toxins produced by Fusarium, and the biosynthesis of toxin was strictly controlled by the genetic information of the strain. This study provides a data basis for the targeted prevention and control of exo-genous mycotoxins in P. heterophylla and a possibility for the development of PCR for rapid detection of toxin contamination.
Caryophyllaceae ; Chromatography, Liquid ; Fusarium/genetics* ; Mycotoxins ; Tandem Mass Spectrometry

Psammosilene tunicoides is one of the main ingredients of the "Yunnan Baiyao". P. tunicoides is an endangered species included in the secondary protection list in China Plant Red Data Book as well as the endemic species in Southwest China. Its natural resources could not meet the needs of pharmaceutical production. Construction of core collection of P. tunicoides will lay the foundation for germplasm improvement and molecular breeding. The sequence variation of the key enzymes gene locus (β-AS) were carried out to survey the population structure and population history of the species. Among the 11 populations across its geographical range, 36 haplotypes were identified. The levels of haplotype diversity (Hd=0.905) were high, while the levels of population differentiation (GST=0.280) were low. Analysisof molecular variance (AMOVA) indicated that a significantly greater proportion of total genetic variationpartitioned among populations thanwithin populations (values of 77.43% and 22.57%, respectively). These results in combination with the star-like phylogenetic network analysis indicate that Hap1 as an ancestral haplotypewas shared in four populations, Hap2, Hap4, Hap15 and Hap16 are occurred in two populations, the remains as private haplotype only distributed in single population. The strategy of core collection was constructed in order to maximumpreserve genetic diversity of P. tunicoides.
Caryophyllaceae ; genetics ; China ; Genetic Variation ; Genetics, Population ; Haplotypes ; Phylogeny ; Plants, Medicinal ; genetics

This paper aimed to study the role of asparagine endopeptidase(AEP) gene in the biosynthesis mechanism of cyclic peptide compounds in Pseudostellaria heterophylla. The transcriptome database of P. heterophylla was systematically mined and screened, and an AEP gene, tentatively named PhAEP, was successfully cloned. The heterologous function verification by Nicotiana benthamiana showed that the expression of the gene played a role in the biosynthesis of heterophyllin A in P. heterophylla. Bioinformatics analysis showed that the cDNA of PhAEP was 1 488 bp in length, encoding 495 amino acids with a molecular weight of 54.72 kDa. The phylogenetic tree showed that the amino acid sequence encoded by PhAEP was highly similar to that of Butelase-1 in Clitoria ternatea, reaching 80%. The sequence homology and cyclase active site analysis revealed that the PhAEP enzyme may specifically hydrolyse the C-terminal Asn/Asp(Asx) site of the core peptide in the HA linear precursor peptide of P. heterophylla, thereby participating in the ring formation of the linear precursor peptide. The results of real-time quantitative polymerase chain reaction(RT-qPCR) showed that the expression level of PhAEP was the highest in fruits, followed by in roots, and the lowest in leaves. The heterophyllin A of P. heterophylla was detected in N. benthamiana that co-expressed PrePhHA and PhAEP genes instantaneously. In this study, the PhAEP gene, a key enzyme in the biosynthesis of heterophyllin A in P. heterophylla, has been successfully cloned, which lays a foundation for further analysis of the molecular mechanism of PhAEP enzyme in the biosynthesis of heterophyllin A in P. heterophylla and has important significance for the study of synthetic biology of cyclic peptide compounds in P. heterophylla.
Genes, vif ; Phylogeny ; Plant Leaves/genetics* ; Peptides, Cyclic ; Cloning, Molecular ; Caryophyllaceae/genetics*

OBJECTIVETo develop an effective identification method for accurately discriminating Psammosilene tunicoides and its confused species by the combined method of microscopic identification and molecular identification, so-called systematic identification of Chinese materia medica (SICMM).

METHODP. tunicoides and its confused species were accurately discriminated by SICMM method, which was established by comprehensively use of microscopic identification and DNA identification method. The DNA identification included the following analysis: the BLAST alignment, specific bases and N-J phylogenetic tree analysis.

RESULTThe cluster crystals were not observed in P. tunicoides, but great deals of them were found in Silene viscidula. Further more, big differences of ITS sequence were observed and analyzed between P. tunicoides and its confused specie of S. viscidula.

CONCLUSIONThe system method is a scientific and accurate method for the identification of P. tunicoides and its counterfeit species.

Base Sequence ; Caryophyllaceae ; chemistry ; classification ; cytology ; genetics ; DNA, Intergenic ; Phenotype ; Phylogeny ; Sequence Alignment

To establish a convenient and rapid method for identification of Pseudostellariae Radix by molecular identification, the rDNA-ITS sequences of Pseudostella riaheterophylla and its adulterants had been aligned to find out specific fragment. The specific primers against the fragment were designed and the PCR amplification conditions were optimized. The fluorescence reaction of the PCR products colored by 100 x SYBR Green I was observed under UV. The concentration of reaction buffer included 5.5 μL DNA Taq polymerase premix, 10 pmol Tzs-2F and 10 pmol Tzs-2R, 20-80 ng template DNA, and plus double sterile distilled water to 25 μL. The PCR thermal profile was as follows: predenaturation at 95 degrees C for 1 min, followed by 30 cycles of denaturation at 95 degrees C for 5 seconds, primer annealing and extension at 56 degrees C for 15 seconds, then it was extension at 72 degrees C for 30 seconds. The fluorescence reaction of Pseudostellariae Radix showed green fluorescence, while adulterants had not. Extraction, amplification DNA and all steps of molecular identification could be completed successfully in 40 minutes. The approach could amplify DNA template of Pseudostellariae Radix specificity, and its product with 1 μL 100 x SYBR Green I could engender green fluorescence under UV. The method was simple and accurate, so it could be used for identification of Chinese traditional medicine.
Caryophyllaceae ; classification ; genetics ; DNA Primers ; genetics ; Drug Contamination ; prevention & control ; Plant Roots ; classification ; genetics ; Polymerase Chain Reaction ; methods

OBJECTIVETo characterize the different varieties of Pseudostellaria heterophylla during cultivation.

METHODUsing systematic selection in the main productive areas, the techniques of random design, all varieties were observed for 3 years.

RESULTThe biological and 425 productive characteristics of P. heterophylla var. macrophylla, P. heterophylla var. Foliolum, and P. heterophylla var. anvense were significantly different (P < 0.01). There were also differences in ecological adaptability, plant characteristics, pollen granule, chromosomes, and isoenzyme of the three cultivars.

CONCLUSIONThe strain types of P. heterophylla was denominated for the first time. The characteristics and productivity index system of P. heterophylla varieties were determined.

Caryophyllaceae ; anatomy & histology ; enzymology ; genetics ; Catechol Oxidase ; analysis ; Chromosomes, Plant ; Ecosystem ; Flowers ; anatomy & histology ; Lipase ; analysis ; Peroxidase ; analysis ; Plant Leaves ; anatomy & histology ; Plant Roots ; anatomy & histology ; Plants, Medicinal ; anatomy & histology ; enzymology ; genetics

The total triterpene saponins of Psammosilene tunicoides have significant pharmacologic activity. Psammosilene tunicoides squalene synthase (PSS) is a gateway enzyme to regulate the biosynthesis of total triterpene saponins extracted from the root of Psammosilene tunicoides which is an endangered species. In this paper, cDNA encoding of PSS was cloned by the degenerate primer PCR and rapid-amplification of cDNA ends (RACE). The full-length of cDNA of PSS is 1663 bp, with an open reading frame (ORF) of 1 245 bp, encoding 414 amino acid polypeptide (calculated molecular mass, 47.69 kDa), 5'UTR (untranslated region) and 3'UTR are 260 bp and 158 bp, respectively. The deduced amino acid sequence of PSS has higher homology with the known squalene synthases of several species such as Panax notoginseng (83%), Panax ginseng (82%) and Glycyrrhiza glabra (82%) than that with Schizosacharomyces pombe (35%), Candida albicans (39%) and Homo sapiens (47%). The characterization of PSS was done by a series of methods, such as prokaryotic expression, the activity of enzyme in vitro, capillary gas chromatography (GC) and capillary gas chromatography mass spectrometry (GC-MS). The results showed that the cell-free extract of E. coli transformed with the recombinant plasmid can effectively convert farnesyl diphosphate into squalene in vitro. GenBank accession number is EF585250. Our research provided important base for the study of Psammosilene tunicoides secondary metabolism and metabolic engineering.
Caryophyllaceae ; enzymology ; genetics ; Cloning, Molecular ; DNA, Complementary ; genetics ; Endangered Species ; Escherichia coli ; genetics ; metabolism ; Farnesyl-Diphosphate Farnesyltransferase ; genetics ; metabolism ; Gas Chromatography-Mass Spectrometry ; Open Reading Frames ; Phylogeny ; Plant Proteins ; genetics ; metabolism ; Plants, Medicinal ; chemistry ; genetics ; Plasmids ; Polymerase Chain Reaction ; Recombinant Proteins ; metabolism ; Sequence Homology, Amino Acid ; Transformation, Genetic