Identification, biological characteristics, and control of pathogen causing Pinellia ternata soft rot in Hubei province / 中国中药杂志

This study was designed to identify the pathogen causing soft rot of Pinellia ternata in Qianjiang of Hubei province and screen out the effective bactericides, so as to provide a theoretical basis for the control of soft rot of P. ternata. In this study, the pathogen was identified based on molecular biology and physiological biochemistry, followed by the detection of pathogenicity and pathogenicity spectrum via plant tissue inoculation in vitro and the indoor toxicity determination using the inhibition zone method to screen out bactericide with good antibacterial effects. The control effect of the bactericide against P. ternata soft rot was verified by the leave and tuber inoculation in vitro. The phylogenetic tree was constructed based on the 16 S rDNA, dnaX gene, and recA gene sequences, respectively, and the result showed that the pathogen belonged to the same branch as the type strain Dickeya fangzhongdai JS5. The physiological and biochemical tests showed that the pathogen was identical to D. fangzhongdai, which proved that the pathogen was D. fangzhongdai. The pathogenicity test indicated that the pathogen could obviously infect leaves at 24 h and tubers in 3 d. As revealed by the indoor toxicity test, 0.3% tetramycin, 5% allicin, and 80% ethylicin had good antibacterial activities, with EC_(50) values all less than 50 mg·L~(-1). Tests in tissues in vitro showed that 5% allicin exhibited the best control effect, followed by 0.3% tetramycin and 10% zhongshengmycin oligosaccharide, and their preventive effects were better than curative effects. Therefore, 5% allicin can be used as the preferred agent for the control of P. ternata soft rot, and 0.3% tetramycin and 10% zhongshengmycin oligosaccharide as the alternatives. This study has provided a certain theoretical basis for the control of P. ternata soft rot.

Effect of different parts of Pinelliae Rhizoma Decoction against airway inflammation and analysis of effective components / 中国中药杂志

This study investigated the material basis and mechanism of Pinelliae Rhizoma Decoction in the treatment of airway inflammation. The cigarette smoke combined with lipopolysaccharide(LPS) was used to induce an airway inflammation model in mice. The expression levels of IL-6 and IL-8 in the bronchoalveolar lavage fluid(BALF) and the phosphorylation levels of p38 and IκB in the lungs of mice were taken as indexes to screen the effective extracts by system solvent extraction from Pinelliae Rhizoma Decoction(dichloromethane extract, ethyl acetate extract, n-butanol extract, etc.). Meanwhile, the human bronchial epithelial(16-HBE) cell model of cigarette smoke extract(CSE)-induced injury was established, and the mRNA expression levels of IL-6 and IL-8 and the phosphorylation levels of p38 and IκB proteins were also taken as indexes to evaluate the anti-inflammatory effect of different extracts of Pinelliae Rhizoma Decoction. The results showed that Pinelliae Rhizoma Decoction significantly antagonized airway inflammation in mice by down-regulating the expression levels of IL-6 and IL-8 in mice with airway inflammation and 16-HBE cells with CSE-induced injury and inhibiting the phosphorylation levels of p38 and IκB. The dichloromethane and ethyl acetate extracts of Pinelliae Rhizoma Decoction showed significant anti-inflammatory effects, while such effects of other extracts were not prominent. Furthermore, the database of Pinelliae Rhizoma composition was constructed, and the components in effective extracts were analyzed by HPLC-TOF-MS and Nano-LC-MS/MS. As revealed by the results, the compositions of the two effective extracts were similar with 36 common components. They were combined and then divided into Pinelliae Rhizoma alkaloids(PTAs) and Pinelliae Rhizoma non-alkaloids(PTNAs) by 732 cation-exchange resin. Further in vitro investigation confirmed the significant anti-inflammatory effect of PTNAs, while such effect of PTAs was not manifest. The MS analysis showed 172 peptides and 7 organic acids in PTNAs. The peptide content in PTNAs was 63.5% measured by quantitative analysis of BCA assay, and the organic acid content was 9.92% by potentiometric titration method. The findings of this study suggested that Pinelliae Rhizoma Decoction could antagonize airway inflammation in mice by inhibiting phosphorylation of p38 and IκB and blocking the activation of MAPK and NF-κB signaling pathways, and the effective components were related to the peptides and organic acids in PTNAs. The above results lay a foundation for the research on the mechanism and material basis of Pinelliae Rhizoma in antagonizing airway inflammation.

Expression of Pinellia ternata leaf agglutinin under rolC promoter confers resistance against a phytophagous sap sucking aphid, Myzus persicae

BACKGROUND: Piercing/sucking insect pests in the order Hemiptera causes substantial crop losses by removing photoassimilates and transmitting viruses to their host plants. Cloning and heterologous expression of plantderived insect resistance genes is a promising approach to control aphids and other sap-sucking insect pests. While expression from the constitutive 35S promoter provides broad protection, the phloem-specific rolC promoter provides better defense against sap sucking insects. The selection of plant-derived insect resistance genes for expression in crop species will minimize bio-safety concerns. RESULTS: Pinellia ternata leaf agglutinin gene (pta), encodes an insecticidal lectin, was isolated and cloned under the 35S and rolC promoters in the pGA482 plant transformation vector for Agrobacterium-mediated tobacco transformation. Integration and expression of the transgene was validated by Southern blotting and qRT-PCR, respectively. Insect bioassays data of transgenic tobacco plants showed that expression of pta under rolC promoter caused 100% aphid mortality and reduced aphid fecundity up to 70% in transgenic tobacco line LRP9. These results highlight the better effectivity of pta under rolC promoter to control phloem feeders, aphids. CONCLUSIONS: These findings suggested the potential of PTA against aphids and other sap sucking insect pests. Evaluation of gene in tobacco under two different promoters; 35S constitutive promoter and rolC phloemspecific promoter could be successfully use for other crop plants particularly in cotton. Development of transgenic cotton plants using plant-derived insecticidal, PTA, would be key step towards commercialization of environmentally safe insect-resistant crops.