Resistance to Tomato Yellow Leaf Curl Geminivirus inNicotiana benthamianaPlants Transformed with a Truncated Viral C1 Gene

Tomato Yellow Leaf Curl Sardinia Virus Rep-Derived Resistance to Homologous and Heterologous Geminiviruses Occurs by Different Mechanisms and Is Overcome if Virus-Mediated Transgene Silencing Is Activated

“…We have previously shown that transgenic expression of a truncated form of the TYLCSV C1 gene encoding Rep's first 210 amino acids (Rep-210), and potentially coexpressing C4, confers resistance to the homologous virus in Nicotiana benthamiana and tomato plants (4,41). We used an antisense strategy to demonstrate that high Rep-210 levels in the transgenic tissues are required to confer TYLCSV resistance (4,41).…”

Recombination between viral DNA and the transgenic coat protein gene of African cassava mosaic geminivirus.

“…The majority of the members of this subgroup have bipartite genomes (DNAs A and B) and are transmitted by the whitefly Bemisia tabaci Gennadius. To date, seven reports of transgenic plants conferring resistance to geminivirus infection have been published (Stanley et al, 1990 ;Day et al, 1990 ;Frischmuth & Stanley, 1994 ;Stenger, 1994 ;Kunik et al, 1994 ;Hong et al, 1996 ;Noris et al, 1996).…”

An RGG sequence in the replication-associated protein (Rep) of Tomato yellow leaf curl Sardinia virus is involved in transcriptional repression and severely impacts resistance in Rep-expressing plants

“…Begomoviruses multiply in the nuclei of infected cells (Hanley-Bowdoin et al, 1999) and perturb the host cell cycle to favour their replication (Ascencio-Ibáñez et al, 2008). In this context, Rep was shown to interact with cell cycle factors such as proliferating cell nuclear antigen or homologues of the retinoblastoma family (pRBR) (Xie et al, 1995;Kong et al, 2000).Nicotiana benthamiana and tomato plants expressing a truncated TYLCSV Rep (Rep-210) are resistant to TYLCSV (Noris et al, 1996;Brunetti et al, 1997) by using a mechanism involving the transcriptional inhibition of the C1-gene promoter and/or the formation of dysfunctional oligomers between Rep-210 and the viral Rep (Brunetti et al, 2001;Lucioli et al, 2003). Further work showed that Rep-130 is the minimal sequence tightly inhibiting C1-gene transcription and virus replication in protoplasts, conferring high levels of virus resistance in transgenic plants (Lucioli et al, , 2008.…”

“…Nicotiana benthamiana and tomato plants expressing a truncated TYLCSV Rep (Rep-210) are resistant to TYLCSV (Noris et al, 1996;Brunetti et al, 1997) by using a mechanism involving the transcriptional inhibition of the C1-gene promoter and/or the formation of dysfunctional oligomers between Rep-210 and the viral Rep (Brunetti et al, 2001;Lucioli et al, 2003). Further work showed that Rep-130 is the minimal sequence tightly inhibiting C1-gene transcription and virus replication in protoplasts, conferring high levels of virus resistance in transgenic plants (Lucioli et al, , 2008.…”

“…To analyse the subcellular compartmentalization of the different Rep versions, nuclear and cytoplasmic fractions were prepared from transgenic lines expressing Rep-210 (line 102.22;Noris et al, 1996), Rep-130 (line 308;Lucioli et al, 2003), Rep-210SAA (lines # 1, # 2 and # 3), Rep-130SAA (line # 4) and Rep-120 (line # 7) using the CelLytic Plant Nuclei Isolation/Extraction kit (semi-pure protocol; Sigma). Four hundred nanograms of total protein quantified using the Experion Pro260 Analysis kit (Bio-Rad) was separated by SDS-PAGE and probed with Rep-antibodies, and also with antibodies against fibrillarin (kindly provided by M. Taliansky, Dundee, UK), used as nuclear control marker.…”