Research Of The Antiviral Function For A Ribosome Inactivation Protein From Camellia Sinensis

In the study of response of tea tree to leafhopper feeding, the cDNA of CsRIPI gene was isolated. By sequence comparison, CsRIPI was found to encode II type ribosome inactivating protein. Ribosome inactivating protein has the ability to antiviral, antifungal, antitumor immunity, which widely exist in plants, so that it becomes the main subject in the study of plant resistance. RIPs might play a role in plant defense. They were proved to be involved in defense against viruses and fungal pathogens. Type II RIPs can attack directly plant eating organisms.CsRIP I gene was transferred into the tobacco genome via Agrobacterium-mediated transformation. The presence of multiple transgene can cause gene silencing and instability, so the transgenic copy number should be analyzed. In this study, the copy number of CsRIP I gene in the genome of transgenic tobacco was detected using real-time fluorescence quantitative PCR. The transgenic tobacco plants were infected mechanically with tobacco mosaic virus, and the development of symptoms of viral infection was compared to those appearing in untransformed control plants. It was found that the number of lesion and the lesion size were reduced in transgenic plants, indicating that expression of CsRIP I increased resistance against TMV.The cDNA fragment which encodes A strand of CsRIP I was amplified, and cloned in prokaryotic expression vector pCznl. A strand of CsRIP I was expressed in E. coli, the recombinant protein of expected size was purified from the supernatant through the Ni resin affinity purification method, which laid foundation for enzyme activity of CsRIP I.