A Disease Syndrome Associated with Expression of Gene VI of Caulimoviruses May Be a Nonhost Reaction

The Cauliflower Mosaic Virus Protein P6 Forms Motile Inclusions That Traffic along Actin Microfilaments and Stabilize Microtubules

“…Recently, a P6-GFP fusion protein was expressed ectopically to reveal a new property for P6 as a nucleocytoplasmic shuttle protein (Haas et al, 2005). In addition, ectopically expressed P6 triggers a hypersensitive response in N. edwardsonii (Palanichelvam et al, 2000) and transgenically expressed P6 causes disease-like symptoms in Nicotiana species and Arabidopsis (Baughman et al, 1988;Goldberg et al, 1991;Zijlstra and Hohn, 1992;Geri et al, 1999;Yu et al, 2003). The results from studies involving P6 ectopic expression have mimicked results from studies with infectious chimeric CaMV isolates regarding the pathogenic properties of P6 (Daubert et al, 1984;Schoelz et al 1986;Wintermantel et al, 1993).…”

Cauliflower Mosaic Virus Gene VI Controls Translation from Dicistronic Expression Units in Transgenic Arabidopsis Plants.

“…It is, therefore, likely that all the variations in staining pattern seen in ORF VI as a transgene were difficult to obtain, and those that survived and expressed ORF VI had an abnormal phenotype, indicating that the ORF VI protein interferes with certain metabolic or developmental plant processes. Such difficulties were also encountered by Schoelz et al, (1991) with ORF Vi-transformed Nicotiana bigelovii, and abnormal phenotypes were observed in severa1 types of nonhost plants by BAlasz (1988), , Kiernan et al (1989), Takahashi et al (1989), and Goldberg et al (1991). The basis of such phenotypic alterations in plants transformed with gene VI will be discussed in detail elsewhere (C. Zijlstra, N. Hernandez, and T. Hohn, manuscript in preparation).…”

“…the cauliflower mosaic disease, the types of symptoms, and, together with other factors, the host range (Daubert et al, 1984;Schoelz et al, 1986;Stratford and Covey, 1989;Daubert and Routh, 1990). Interestingly, expression from ORF VI transgenes also leads to viruslike symptoms (Bálasz, 1988;Kiernan et al, 1989;Takahashi et al, 1989;Goldberg et al, 1991;Schoelz et al, 1991). Plants that are not systemic hosts for CaMV are especially affected, whereas certain transformed host plants remain symptomless .…”

Assessment of CaMV-mediated gene silencing and integration of CaMV into GM plants with a 35S RNA promoter

“…Many transgenes have been expressed in tobacco, which is resistant to systemic infection by CaMV, and also resistant to local infection by most strains of CaMV (Goldberg et al, 1991;Gracia and Shepherd, 1985). Therefore, we used CaMV strain W260, as this was capable of limited local infection in tobacco, to examine the effect that local CaMV infection might have on the local and systemic expression of a transgene regulated by the CaMV 35S RNA promoter.…”