The present invention relates to a method for the preparation of transgenic plants, tissues or plant cells thereof having long-lasting resistant to the geminiviruses by a) “identification” or “selection” of a viral gene sequence encoding an amino acid sequence able to confer resistance against geminiviruses; b) mutagenesis or “choice” of the viral gene sequence so as to make it an ineffective target of the post-trascriptional silencing induced by infecting geminivirus; and c) insertion of the geminivirus mutated or chosen gene sequence obtained in step b) through a construct as described previously, in the plant, tissue or plant cell thereof.