2001 Fiscal Year Final Research Report Summary

Analysis of gene silencing in higher plants that is established by novel molecular mechanisms

Research Project

Project/Area Number	12640628
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	植物生理
Research Institution	CHIBA UNIVERSITY
Principal Investigator	KODAMA Hirotaki Faculty of Horticulture, Chiba University, Associated professor, 園芸学部, 助教授 (70302536)
Project Period (FY)	2000 – 2001
Keywords	post-transcritional gene silencing / fatty acid desaturase / α-linolenic acid / RNA processing / translational regulation
Research Abstract	A tobacco endoplasmic reticulum ω-3 fatty acid desaturase (NtFAD3) catalyzes the formation of α-linolenate. A transgenic tobacco plant (S44) over-producing the NtFAD3 mRNA exhibited an extremely low α-linolenate level in leaves, but in root tissues α-linolenate accumulated successfully. In the S44 leaves the RNAs for introduced NtFAD3 gene accumulated in a gene-dosage-dependent manner, suggesting that in the silenced leaves of the S44 homozygous plants the transgene's expression is suppressed at the (post)translational steps. The processing of nascent RNAs for endogenous NtFAD3 and the plastid isozyme gene was severely inhibited in the nuclei isolated from S44 leaves, which was followed by degradation of these mRNAs. These data indicate that block of the ω-3 desaturation step is achieved by multiple silencing processes.

(4 results)