|
> Wissenschaftliche Publikationen <
|
A ribozyme gene and an antisense gene are equally effective in conferring resistance to tobacco mosaic virus on transgenic tobacco. Molecular & General Genetics 250, 329-338.
| De Feyter R., Young, M., Schroeder, K., Dennis, E. S., Gerlach, W. (1996).
| Ribozymes of the hammerhead class can be designed to cleave a target RNA in a sequence-specific manner and can potentially be used to specifically modulate gene activity. We have targeted the tobacco mosaic virus (TMV) genome with a ribozyme containing three catalytic hammerhead domains embedded within a 1 kb antisense RNA. The ribozyme was able to cleave TMV RNA at all three target sites in vitro at 25 degree C. Transgenic tobacco plants were generated which expressed the ribozyme or the corresponding antisense constructs directed at the TMV genome. Six of 38 independent transgenic plant lines expressing the ribozyme and 6 of 39 plant lines expressing the antisense gene showed some level of protection against TMV infection. Homozygous progeny of some lines were highly resistant to TMV; at least 50% of the plants remained asymptomatic even when challenged with high levels of TMV. These plants also displayed resistance to infection with TMV RNA or the related tomato mosaic virus (ToMV). In contrast, hemizygous plants of the same lines displayed only very weak resistance when inoculated with low amounts of TMV and no resistance against high inoculation levels. Resistance in homozygous plants was not overcome by a TMV strain which was altered at the three target sites to abolish ribozyme-mediated cleavage, suggesting that the ribozyme conferred resistance primarily by an antisense mechanism.
Ribozymes of the hammerhead class can be designed to cleave target RNA sequence-specifically and can potentially be used to modulate gene activity. Here, a ribozymes was able to cleave tobacco mosaic virus (TMV) RNA in vitro. Transgenic plants expressing this ribozyme or an antisense gene showed some level of protection against TMV infection, homozygous progeny of some lines were highly resistant to TMV. As resistance was not overcome by a TMV strain, altered at the target sites to abolish ribozyme-mediated cleavage, it is suggested that the ribozyme conferred resistance primarily by an antisense mechanism.
| | Zurück |
|
|
Interviews mit Forschern
Erfahren Sie mehr über einzelne Forschungsprojekte und die Leute, die dahinterstehen. | 
Gentechnik im Klassenzimmer
Aufgaben zum Thema Gentechnik, die in den Schulunterricht integriert werden können. | 
Genomik und Proteomik
Wie man heute die Gene und Proteine eines Organismus untersucht. | 
Forschungseinblicke
Verfolgen Sie die Arbeit an aktuellen Projekten, z.B. am Weizen, Fadenwurm oder in der Krebsforschung. |
|
