【１】Development of platform plants for production of recombinant proteins using genome editing technology
Plants have a defense system, known as RNA silencing mechanism, against foreign genetic elements, such as viruses. RNA silencing mechanism would frequently degrade transgene derived mRNAs, thereby reducing the yield of recombinant proteins.
To repress RNA silencing mechanism for mass production of recombinant proteins in plants, we produced RNA-dependent RNA polymerase 6 (RDR6) gene, one of major component of RNA silencing mechanism, -knockout Nicotiana benthamiana (ΔRDR6 plants) by CRISPR/Cas9 technology. In transient green fluorescent protein (GFP) expression assay, the ΔRDR6 plants could produce larger amounts of GFP than wild-type plants (1). Thus, it was cleared that the repression of RNA silencing mechanism would be useful for mass production of recombinant proteins in plants.
This work was supported by Japan Society for the Promotion of Science (JSPS) KAKENHI (Grant no. 16K14833).
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- Matsuo K, Atsumi G. CRISPR/Cas9-mediated knockout of the RDR6 gene in Nicotiana benthamiana for efficient transient expression of recombinant proteins. Planta. 250 (2019) 463-473.
【２】Production of canine interferon-producing transgenic strawberry plants
Increase of canine periodontal disease becomes a serious problem according to life-span extension of family dogs. In Japan, it was reported that over 80% of three-year-old or more dogs have contracted periodontal disease, thus, the development of the effective medicine for periodontal disease has been desired. Canine interferon-α (cIFN-α) have been expected as a curative for canine periodontal disease. We achieved successful production of transgenic strawberry plants that produce cIFN-α in their fruits. The cIFN-α producing strawberry is expected as an edible medicine, in fact, we confirmed that this transgenic strawberry had protective and therapeutic effects against canine periodontal disease. Now, the research is aggressively advanced to perform clinical trials. This research and development has been carried out with a pharmaceutical company.
【３】Development of efficient targeted DNA methylation technology using plant virus
RNA-directed DNA methylation (RdDM) is critical for regulating DNA methylation in plant genome. We aim for developing efficient targeted DNA methylation technology in endogenous gene by artificially inducing RdDM in the target region using cucumber mosaic virus (CMV) vector. We could successfully introduce DNA methylation in the targeted region of endogenous metabolic gene and are attempting to improve the efficiency.
【４】Development of hydroponic cultivation methods
We have been developing cultivation techniques for medicinal plants and herbs that produce functional materials. We have developed a hydroponic cultivation method that accelerates the period until flowering. General open-field lavender blooms three years after sowing, but using this technology, it is possible to bloom two months after sowing, and it continues to bloom until winter.
