Analysis of cultivar- and tissue-specific biogenesis of viroid-specific small RNA in relation to viroid pathogenicity

2014 Fiscal Year Final Research Report

• Project/Area Number: 24380026
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Plant pathology
• Research Institution: Hirosaki University
• Principal Investigator: SANO Teruo 弘前大学, 農学生命科学部, 教授 (30142699)
• Co-Investigator(Kenkyū-buntansha): HARADA Takeo 弘前大学, 農学生命科学部, 教授 ; TANEDA Akito 弘前大学, 理工学研究科, 准教授 (70332492)
• Research Collaborator: OWENS R.A. USDA, Agriculture Research Service Molecular Plant Pathology Laboratory
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: ウイロイド / ノンコーディングRNA / RNAサイレンシング / siRNAシークエンス / 抵抗性 / 病原性

Outline of Final Research Achievements

Deep sequencing analysis of PSTVd-small RNA in leaf and stem of tomato infected with severe and mild PSTVd isolates revealed that PSTVd-small RNA was less abundant in leaf tissues than in stem, and in those infected with mild isolate than with severe. Reduction of PSTVd-small RNA in mild isolate was conspicuous especially in the regions containing the nucleotides 118, 126 and 201. Relative expression levels of some host microRNAs were down-regulated in PSTVd infected plants. Especially, miR159 decreased to nearly 50% and miR319 decreased to 33-63% of that of the healthy.
Transgenic N.benthamiana and tomato lines expressing varieties of hairpin RNAs were created, which included various PSTVd-derived sequences, tomato gibberellin-related gene, DCL2 gene and AGO2 gene. Four of the 21 lines of transgenic N.benthamiana expressing hairpin RNA of PSTVd-related sequences showed delay of the infection and reduction of PSTVd accumulation.

Free Research Field

農学