Cauliflower Mosaic Virus as a probe for studying gene expression in plants

Abstract

Cauliflower Mosaic Virus (CaMV) represents a natural set of cloned genes, which have to replicate and be expressed in plant cells. Because CaMV DNA cloned in a plasmid is infectious, the viral genome can be assayed for dispensable regions and used as an episomal vector for the introduction and expression of foreign genes in host plants; however, its usefulness is restricted by the limited payload it can accommodate and by the existence of a reverse transcription step in the viral replication cycle. Direct gene transfer and viral infection mediated by Agrobacterium have now extended the possibilities of manipulating CaMV DNA to non‐hosts and allowed regeneration of transgenic plants, which should permit dissection of the functions of the various viral genes. Analysis of CaMV promoters has also defined enhancer sequences that maximize expression of foreign genes in transgenic plants. Finally, the translational strategy of CaMV is now being investigated by direct introduction into protoplasts of DNA constructs that contain combinations of sequences thought to regulate translation of the viral transcripts.

An Experimental Test of the Transmission-Virulence Trade-Off Hypothesis in a Plant Virus

“…The plant virus Cauliflower mosaic virus (CaMV), is a double‐stranded DNA (dsDNA) virus able to infect Brassicaceae in nature (e.g., Raybould et al 1999; Pagan et al 2010), inducing more or less severe symptoms (Al‐Kaff and Covey 1994, 1995). CaMV genetic matrix codes for a polycistronic RNA that (1) codes for all viral proteins (six were detected in planta, Maule et al 1989) and (2) serves as the template of the viral reverse transcriptase to create the new viral dsDNA that is encapsidated (Pfeiffer and Hohn 1989). This Caulimovirus species can be horizontally transmitted by at least 27 aphid species (Broadbent 1957; Kennedy et al 1962; Moreno et al 2005) in a noncirculative manner (i.e., no circulation and viral replication in aphids, Ng and Falk 2006; Blanc 2008).…”

Engineered resistance against plant virus diseases

“…A detailed explanation of the production of fransgenic plants is beyond the scope of this review, and the reader is directed to any one of a number of reviews of the topic (e.g., Fraley et al 1986, Klee et al 1987, Scheli 1987, Weising et al 1988. The 35S or 19S promoters derived from cauliflower mosaic virus have been used most frequently to drive the expression of CP genes in transgenic plants (Pfeiffer and Hohn 1989). A more detailed explanation of the construction of chimeric CP geties and their expression in transgenic plants has been previously reported (Beachy 1988,1990, Hemenway et al 1989).…”