The current interest in green technologies has directed attention to the use of
plant systems for several applications, including traditional crop plant systems used for
biomass production, large-scale synthesis of a great number of recombinant proteins,
and biofuels production. In this context, plant viruses are very useful instruments for
plant biotechnology applications, constituting suitable tools for heterologous gene
expression. Virions are particles with a complex composition, but their stability allows
them to be used for the development of numerous biotechnological applications and as
research tools for plant functional genomics studies. The development of infectious
full-length viral clones is a strategy extensively employed as an alternative tool for
introducing viruses into plants via inoculation with Agrobacterium tumefaciens.
Another strategy, called RNA interference, a plant gene expression regulation
mechanism based on post-transcriptional gene silencing, has extensively been
employed to down-regulate the expression of endogenous transcripts and displays a
number of biotechnological applications. Additionally, transgenic expression of viral
proteins has been used to achieve pathogen-derived resistance, a mechanism that
confers resistance to viral infections in agricultural crops. In this chapter we will
discuss several strategies and methods for plant gene expression which employ plant
viruses developed over the past decade.
Keywords: Agroinfiltration, Infectious clones, Plant virus, Post-transcriptional
gene silencing, RNA interference, Viral expression vectors, Virus-induced gene
silencing.
