Identification of a TuMV isolate (TuMV-ZR) from Pseudostellaria heterophylla and its development into a viral expression vector.

Pseudostellaria heterophylla (P. heterophylla) is a popular Chinese medicinal herb that is cultivated widely in China. Viral infection is commonly encountered during the production of P. heterophylla. To identify viruses causing P. heterophylla disease, sRNA and mRNA libraries were built for 2 sets of P. heterophylla plants, one set that was planted only once (FGP) and one that was planted three consecutive three times (TGP) in a field, using virus-free tuberous roots as reproductive materials. A comprehensive procedure, including assembling virus-derived sRNA (vsRNA), assessing and cloning the full-length viral genome, building an infectious cloning vector and constructing a virus-based expression vector, was performed to identify viruses infecting P. heterophylla. Ultimately, 48 contig-related viruses were mined from 6 sRNA and 6 mRNA P. heterophylla libraries. A 9762-bp fragment was predicted to be the complete genome of TuMV virus. This sequence was cloned from P. heterophylla, and its infectivity was evaluated using the virus-infection model plant Nicotiana benthamiana (N. benthamiana) and host plant P. heterophylla. The resulting 9839-bp viral genome was successfully obtained from P. heterophylla and identified as a new P. heterophylla TuMV-ZR isolate. Simultaneously, TuMV-ZR infectious clones were shown to effectively infect P. heterophylla. Furthermore, TuMV-ZR expression vectors were developed, and the ability of a TuMV-ZR-based vector to express foreign genes was determined by analysis with the reporter gene EGFP. TuMV-ZR-based vectors were found to continuously express foreign genes in different organs of P. heterophylla throughout the whole vegetative period. In addition, TuMV-ZR vectors carrying EGFP accumulated in the tuberous roots of P. heterophylla, confirming that tuberous roots are key targets for viral infection and transmission. This study revealed the core pathogenicity of P. heterophylla mosaic virus and developed a new TuMV-ZR-based expression tool that led to long-term protein expression in P. heterophylla, laying the foundation for the identification of the mechanisms of P. heterophylla infection with mosaic viruses and developing tools to express value proteins in the tuberous roots of the medicinal plant P. heterophylla.

[QTRAP LC-MS/MS Analytical Study on Nucleosides and Nucleobases of Pseudostellariae Radix Cultivated in Different Idioplasm Resources].

OBJECTIVE: To analyze nucleosides and nucleobases of Pseudostellariae Radix cultivated in different idibplasni resources and to compare the differences. METHODS: QTRAP LC-MS/MS method was applied for the analysis of 13 kinds of nucleosides and nucleobases in Pseudostellariae Radix and the data obtained was analyzed by SPSS 16. 0 software. RESULTS: There were some differences between Pseudostellariae Radix cultivated in different idioplasm resources. The highest amount of nucleosides and nucleobases was ZS2 which came from Zherong in Fujian Province. The total content of nucleosides and nucleobases in the sample from Shibing in Guizhou Province was the lowest. There was little difference between ZS1 (Zherong in Fujian Province) and XC(Xuancheng in Anhui Province). CONCLUSION: This study provides evidence for the influence of eco-environment on the metabolites of Pseudostellariae Radix.

[Studies on strain characteristics of Pseudostellaria heterophylla varieties].

OBJECTIVE: To characterize the different varieties of Pseudostellaria heterophylla during cultivation. METHOD: Using systematic selection in the main productive areas, the techniques of random design, all varieties were observed for 3 years. RESULT: The 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. CONCLUSION: The strain types of P. heterophylla was denominated for the first time. The characteristics and productivity index system of P. heterophylla varieties were determined.