ABSTRACT
Objective:To investigate the allelopathic effects of water extracts from rhizosphere soil of three medicinal plants Rehmannia glutinosa，Pinellia ternata and Isatis indigotica on seed germination and seedling growth of Polygala tenuifolia， screen the stubble varieties suitable for crop rotation with P. tenuifolia， and provide some scientific basis for continuous cropping obstacles of P. tenuifolia. Method:The bioassay method was used to study the effects of rhizosphere soil water extracts from three medicinal plants Rehmannia glutinosa，Pinellia ternata and Isatis indigotica at concentrations of 0.3，0.6，0.9 g·mL-1 on the germination of P. tenuifolia seed and seedling growth. Result:The rhizosphere soil water extracts of Rehmannia glutinosa and Pinellia ternata showed basically low-promotion and high-inhibition concentration effects on the final germination rate，germination potential，and germination index of P. tenuifolia seeds，while the water extract of Isatis indigotica showed significant allelopathic inhibition effect. All three rhizosphere soil water extracts showed significant allelopathic inhibition effects on the growth index of P. tenuifolia seedlings. Among them，the rhizosphere soil water extract of Rehmannia glutinosa showed lower inhibitory effect on the plant height and root length of P. tenuifolia seedlings than the other two water extracts. The photosynthetic pigment content，proline（Pro） content，and soluble sugar content of P. tenuifolia chinensis seedlings were the highest under 0.3 g·mL-1 soil water extract of Rehmannia glutinosa， with relatively higher content of soluble protein， and relatively lower content of hydrogen oxide（H2O2）. Under the treatment of 0.9 g·mL-1 soil water extract of Rehmannia glutinosa，P. tenuifolia seedlings had the highest peroxidase（POD） and superoxide dismutase（SOD） activities，low catalase（CAT） activity，and lowest content of malondialdehyde（MDA）. Conclusion:Based on the comprehensive analysis of the above experimental data and allelopathic effects，the water extract of rhizosphere of Rehmannia glutinosa can promote the germination of P. tenuifolia seeds to a certain extent，and lay the foundation for seedling resistance to biochemical stress. Therefore， Rehmannia glutinosa is more suitable for crop rotation with P. tenuifolia.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the cleavage of HBV core protein in vivo by proprotein convertase furin or its family members and observe the intracellular localization of the putative cleaved product.</p><p><b>METHODS</b>Recombinant HBV core protein was incubated with furin under different conditions in vitro, and the reaction was checked with Western blotting. The recombinant vectors expressed the putative cleaved fragment and intact core protein (serves as control) were constructed. The stable expression cell lines were established by transfecting constructs into HepG2 cell line, for which indirect immunofluorescence staining was used by monoclonal anti-HBc against the region shared by core protein and its cleaved product .The confocal microscopy was carried out to observe the intracellular distribution.</p><p><b>RESULTS</b>HBV core protein was cleaved by furin in vitro under different tested conditions. The molecular weight of the major cleaved product just about 15,000 was in concordance with the expectation. The expressed cleaved fragment could react to the monoclonal antibody against core protein, and mainly located in cytosol in particle style just like the intact core protein.</p><p><b>CONCLUSION</b>HBV core protein can be cleaved by furin in vitro. The major cleaved product has similar antigenicity and subcellular distribution to core protein. These data suggest that proprotein convertase furin or its family members play important roles in HBV replication regulation, and the cleaved product may be involved in antiviral immunity of HBV infection. Further investigations are imperative.</p>