Recent research progress of selenium polysaccharides from medicinal plants / 中国中药杂志

Selenium polysaccharides (Se polysaccharides) are a kind of organic selenium compounds which obtain the activities from Se and polysaccharides. Comparing to Se or polysaccharides, Se polysaccharides exhibit improved biological activities and are more prone to be absorbed by human bodies, therefore, they have been widely used in medical applications, such as immunomodulation, anti-tumor, anti-oxidation, anti-aging. Due to their unique pharmacological activities, Se polysaccharides from medicinal plants have gradually become a research hotspot. However, only a few of Se polysaccharides have been separated and purified in recent years. The structure of polysaccharides is also very complex, therefore, determination of the chemical structure and mechanism of bioactivity of Se polysaccharide in vivo remain to be further studied. This article systematically introduced the main source and biological activities of Se polysaccharides from medicinal plants. The purpose of this review is to provide a basis for the further research of Se polysaccharides.

Diversity of agronomic traits of Paris polyphylla var. chinensis and their correlation with rhizome yield and active compositions / 中国中药杂志

The supply deficiency of crude medicinal plant of Paris polyphylla var. chinensis has become a bottleneck for related medicinal industry. An important approach to increase herbal production is to breed high-yield cultivated variety, which characterized ideal plant morphology. In the present study, we collected 99 wild germplasm resources of P. polyphylla and then measured their 12 main agronomic traits and contents of polyphyllin Ⅶ,Ⅵ,Ⅱ,Ⅰ. Followed analyses were used to characterize those traits and explore the potential connection with herbal yield or quality. The results showed that: ①There was ample morphological diversity in wild P. polyphylla, whose variation of agronomic traits reduced according to followed order: content of polyphyllin, weight of dry rhizome, petiole length, stem length, petal length, pedicel length, sepal length, leaf width, leaf length, sepal width, leaf number, stamen number, petal number. ② Most of those traits were significantly correlated to each other and generally represented the characterization of photosynthetic organs or reproductive organ. ③The total content of polyphyllin Ⅶ,Ⅵ,Ⅱ,Ⅰvaried between 0.02% and 0.87% and averagedat 0.13%, which showed no significant correlation with any agronomic trait. ④Plant breeders should play more attention on those germplasm resources with large leaves, large sepals and high stem.

Cloning, subcellular lacalization and expression analysis of chloroplast-targeted Obg gene in Cyathula officinalis / 中国中药杂志

According to ObgC gene sequences from Cyathula officinalis genomic data, the specific primers were designed, and a full-length CoObgC cDNA (2 226 bp) was obtained by polymerase chain reaction (PCR) and rapid amplification of cDNA ends (RACE) methord. Sequence alignment showed that CoObgC gene contained a 1 818 bp open reading frame (ORF) encoding 605 amino acids. Sequence analysis predicted that molecular weight of CoObgC protein was about 66.39 kDa, the academic isoelectric point was 5.35, and the protein was stable protein. Then multiple sequence alignment was applied to construct phylogenetic tree. The real-time fluorescence quantification PCR (RT-qPCR) demonstrated that a high expression level in leaf, followed by root and flower, the low transcription was in stem. The recombinant vector pCABIA2300-CoObgC was constructed and introduced into tobacco epidermal cells by agrobacterium-mediated transformation, green fluorescence was tested and targeted to chloroplast under a laser scanning confocal microscope. These findings will be helpful to lay a foundation for studying the structure and function of CoObgC gene, and elucidating C. officinalis molecular biology experiment.

Physiological and biochemical change of Paris seed in after-ripening during variable temperature stratification / 中国中药杂志

In order to explore the dormancy physiological and biochemical mechanism of Paris seeds, the seed embryo growth courses, and the dynamic change of 5 enzymes, include SOD, POD, CAT, MDH, G-6-PDH were measured during variable temperature stratification. The results indicated that Paris seeds embryo grew quickly after 40 d in warm-stratification (18 ± 1) °C, at the meantime the metabolic activity was significantly strengthened. These facts showed that Paris seeds turned into physiological after-ripening process. After 60-80 d, the morphological embryo after-ripping process basically completed, and the following cold-stratification (4 ± 1) °C furthered Paris seed to finish physiological after-ripening. After 40 d, the activity of MDH decreased while G-6-PDH increased significantly. This showed that the main respiratory pathway of seed changed from TCA to PPP, which benifited breaking seed dormancy. In the whole period of stratification process, the activity variation of SOD and CAT was insignificantly and the activity of POD was enhanced significantly after shifting the seed in cold stratification process. This showed that SOD, CAT had no direct effects on breaking Paris seed dormancy but keeping the seed vigor, while the POD might involve in the process of Paris seed dormancy breaking.