Study On The Interaction Between Small Molecules With Anti - Southern Duck Dwarf Disease And The Defense Gene And PR - 1a Protein In Rice

PR-la gene could largely expressed after stimulated by external environment, the expression level of PR-1a gene is closely related with disease resistance of the plants, it is saying that PR-1a gene plays an important role in the progress of resisting external stimulation. Spraying Dufulin and Ningnanmycin on the tobacco plants which were infected with TMV could induce up-regulation of PR-1a gene, thus induce the tobacco plants produce disease resistance. In field trials, we found that Dufulin and Ningnanmycin had good effect against SRBSDV. Whether Dufulin and Ningnanmycin could regulate up-regulation of PR-1a gene to induce rice produce disease-resistance is not studied. Pathogenesis-related(PR) proteins were a kind of water-soluble proteins,PR-1a protein was an essential protein in the progress of resisting external stimulation, it has vital significance to research the interactions of PR-1a and antiviral compounds.In this study, through RT-qPCR, the influence of Dufulin and Ningnanmycin on the expression quantity of PR-1a gene in rice which were infected with SRBSDV in different times were researched. By the prokaryotic expression system, PR-1a protein was successfully expressed. Degeneration, purification and renaturation of PR-1a protein were also successfully finished. Otherwise, PR-1a protein was indentified by protein MS. Fluorescence spectroscopy and Isothermal Titration Calorimetry were used to study the interactions of Ningnanmycin, Lentinan, Dufulin, GUJHZX-039, GUJHZX-023 and GUJHZX-027 on PR-1a protein.The results of RT-qPCR indicated that, Dufulin and Ningnanmycin could induce up-regulation of PR-1a gene in rice, the capacity of Dufulin induce up-regulation of PR-1a gene was stronger than Ningnanmycin, at the first and third day when treated with Dufulin and Ningnanmycin, the expression quantity of PR-1a gene rose, it was because that rice was infected with double stimulations which include antiviral agents and virus. But at the fifth day, the expression quantity of PR-1a gene declined, it was because that Dufulin and Ningnanmycin could inhibit the reproduction of parts of SRBSDV. At the seventh day, the expression quantity of PR-1a gene rose again, it was because that the pesticide effect of Dufulin and Ningnanmycin reduced, virus which were not inhibited began to reproduce and resulted in the up-regulation of PR-1a gene again. The data of fluorescence spectroscopy and ITC showed that the affinity of Dufulin and PR-1a is the highest, the second is GUJHZX-023, GUJHZX-039 is very weak, but Ningnanmycin, Lentinan and GUJHZX-027 can’t bind with PR-1a protein.