The use of geminiviruses in biotechnology and plant molecular biology, with particular focus on Mastreviruses

Abstract

The Geminiviridae are a large family of plant viruses which have small single stranded circular DNA genomes. The minichromosome-like double stranded replicative form of the viral genome exists at very high copy number in the nuclei of infected cells. This feature of geminiviruses has attracted particular interest from molecular biologists, because of the potential for their use as plasmid-like extrachromosomal replicons in plant cells. Most research on applications of geminiviruses in applied plant molecular biology has focused on the mainly bipartite, whitefly-transmitted Begomoviruses, all of which infect dicotyledonous plants. In this article, we critically review the applications of the monopartite, mainly cereal-infecting Mastreviruses for solving problems in plant biotechnology and molecular biology. We discuss the use of Mastreviruses as markers and vectors for gene transfer, as transient or infectious gene vectors, and as episomal gene amplification systems for enhancing gene expression in transgenic plants. We also examine the potential for use of geminiviral genetic elements such as promoters and transcription factors for manipulating gene expression in transgenic plants.