Elucidation of pathogenetic expression mechanism of cyclic single-stranded RNA viroids ₋Search for target host factors₋

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15842
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 39040:Plant protection science-related
• Research Institution: Hirosaki University (2020); Akita Prefectural University (2019)
• Principal Investigator: TSUSHIMA DAIKI 弘前大学, 医学研究科, 研究機関研究員 (20803943)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: ウイロイド / PSTVd / スモールRNA / マイクロRNA

Outline of Final Research Achievements

Regarding the nucleotide mutations characteristic of the left hand half molecular of the PSTVd attenuated isolates, we constructed 10 mutants that mutated nucleotide mutations into PSTVd virulent isolates. Then, each infectious clones were inoculated to Rutgers tomatoes, and all the mutants were infected. It was revealed that the nucleotide sequence of the mutant after infection induces co-mutation with high probability, but has little effect on the pathogenicity. However, a single mutagenesis of base 42C to U resulted in attenuation of some virulent strains.
We performed In silico analysis based on the data obtained in the next-generation sequence analysis. For the microRNA species found as the target host factor, detection probes of two target candidates were selected and tested, but no difference was found.

Free Research Field

植物病理学

Academic Significance and Societal Importance of the Research Achievements

日本国内では、行政機関等の研究所でウイロイド病の診断や作物への影響の調査は行っているが、ウイロイドの病原性メカニズムに関する研究までは至っておらず、本研究はこれまでに得られた基礎データをもとに進展させた研究であると言える。近年、ヒトの脳内にもウイロイドと同じ環状一本鎖RNAが多数存在していることが発見され、その機能が注目されている。すなわち、本研究によって得られる知見は、将来的には植物だけでなく動物の研究にも有益な情報を提供できる可能性を秘めている。