Open AccessRNAi‐mediated resistance to Potato spindle tuber viroid in transgenic tomato expressing a viroid hairpin RNA construct
Author(s) -
SCHWIND NORA,
ZWIEBEL MICHÈLE,
ITAYA ASUKA,
DING BIAO,
WANG MINGBO,
KRCZAL GABI,
WASSENEGGER MICHAEL
Publication year - 2009
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/j.1364-3703.2009.00546.x
Subject(s) - viroid , potato spindle tuber viroid , trans acting sirna , biology , rna interference , small hairpin rna , rna , rna silencing , small interfering rna , virology , genetics , gene
SUMMARY Because of their highly ordered structure, mature viroid RNA molecules are assumed to be resistant to degradation by RNA interference (RNAi). In this article, we report that transgenic tomato plants expressing a hairpin RNA (hpRNA) construct derived from Potato spindle tuber viroid (PSTVd) sequences exhibit resistance to PSTVd infection. Resistance seems to be correlated with high‐level accumulation of hpRNA‐derived short interfering RNAs (siRNAs) in the plant. Thus, although small RNAs produced by infecting viroids [small RNAs of PSTVd (srPSTVds)] do not silence viroid RNAs efficiently to prevent their replication, hpRNA‐derived siRNAs (hp‐siRNAs) appear to effectively target the mature viroid RNA. Genomic mapping of the hp‐siRNAs revealed an unequal distribution of 21‐ and 24‐nucleotide siRNAs of both (+)‐ and (–)‐strand polarities along the PSTVd genome. These data suggest that RNAi can be employed to engineer plants for viroid resistance, as has been well established for viruses.