Precisely full length, circularizable, complementary RNA: an infectious form of potato spindle tuber viroid.
Proc Natl Acad Sci U S A
; 95(11): 6560-5, 1998 May 26.
Article
em En
| MEDLINE
| ID: mdl-9601006
ABSTRACT
The replication of many viral and subviral pathogens as well as the amplification of certain cellular genes proceeds via a rolling circle mechanism. For potato spindle tuber (PSTVd) and related viroids, the possible role of a circular (-)strand RNA as a template for synthesis of (+)strand progeny is unclear. Infected plants appear to contain only multimeric linear (-)strand RNAs, and attempts to initiate infection with multimeric (-)PSTVd RNAs generally have failed. To examine critically the infectivity of monomeric (-)strand viroid RNAs, we have developed a ribozyme-based expression system for the production of precisely full length (-)strand RNAs whose termini are capable of undergoing facile circularization in vitro. Mechanical inoculation of tomato seedlings with electrophoretically purified (-)PSTVd RNA led to a small fraction of plants becoming infected whereas parallel assays with an analogous tomato planta macho viroid (-)RNA resulted in a much larger fraction of infected plants. Ribozyme-mediated production of (-)PSTVd RNA in transgenic plants led to the appearance of monomeric circular (-)PSTVd RNA and large amounts of (+)PSTVd progeny. No monomeric circular (-)PSTVd RNA could be detected in naturally infected plants by using either ribonuclease protection or electrophoresis under partially denaturing conditions. Although not a component of the normal replicative pathway, precisely full length (-)PSTVd RNA appears to contain all of the structural and regulatory elements necessary for initiation of viroid replication.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Viroides
/
Replicação Viral
/
Solanum tuberosum
/
RNA Viral
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos