Mutation of the conserved late element in geminivirus CP promoters abolishes Arabidopsis TCP24 transcription factor binding and decreases H3K27me3 levels on viral chromatin.

In geminiviruses belonging to the genus Begomovirus, coat protein (CP) expression depends on viral AL2 protein, which derepresses and activates the CP promoter through sequence elements that lie within the viral intergenic region (IR). However, AL2 does not exhibit sequence-specific DNA binding activity but is instead directed to responsive promoters through interactions with host factors, most likely transcriptional activators and/or repressors. In this study, we describe a repressive plant-specific transcription factor, Arabidopsis thaliana TCP24 (AtTCP24), that interacts with AL2 and recognizes a class II TCP binding site in the CP promoter (GTGGTCCC).

siRNA biogenesis and advances in topically applied dsRNA for controlling virus infections in tomato plants.

A non-transgenic approach based on RNA interference was employed to induce protection against tomato mosaic virus (ToMV) infection in tomato plants. dsRNA molecules targeting the cp gene of ToMV were topically applied on plants prior to virus inoculation. Protection was dose-dependent and sequence-specific.

Characterization of Local and Systemic Impact of Whitefly () Feeding and Whitefly-Transmitted Tomato Mottle Virus Infection on Tomato Leaves by Comprehensive Proteomics.

Tomato mottle virus (ToMoV) is a single-stranded DNA (ssDNA) begomovirus transmitted to solanaceous crops by the whitefly species complex (), causing stunted growth, leaf mottling, and reduced yield. Using a genetic repertoire of seven genes, ToMoV pathogenesis includes the manipulation of multiple plant biological processes to circumvent antiviral defenses. To further understand the effects of whitefly feeding and whitefly-transmitted ToMoV infection on tomato plants ( 'Florida Lanai'), we generated comprehensive protein profiles of leaves subjected to feeding by either viruliferous whiteflies harboring ToMoV, or non-viruliferous whiteflies, or a no-feeding control.

Dendritic cells, macrophages, NK and CD8 T lymphocytes play pivotal roles in controlling HSV-1 in the trigeminal ganglia by producing IL1-beta, iNOS and granzyme B.

Background: Herpes simplex virus type 1 (HSV-1) cause not only mild symptoms but also blindness and encephalitis. It was previously shown that the immune response against HSV-1 occurs mainly in the trigeminal ganglia (TG) and that Toll-like receptors 2 and 9 (TLR2/9) are important in mediating this response. It was also demonstrated that iNOS (nitric oxide synthase) and interleukin 1 beta (IL-1β) play an essential role in the defense against HSV-1 infection.

Defense against HSV-1 in a murine model is mediated by iNOS and orchestrated by the activation of TLR2 and TLR9 in trigeminal ganglia.

Background: Herpes simplex 1 (HSV-1) causes various human clinical manifestations, ranging from simple cold sores to encephalitis. Innate immune cells recognize pathogens through Toll-like receptors (TLRs), thus initiating the immune response. Previously, we demonstrated that the immune response against HSV-1 is dependent on TLR2 and TLR9 expression and on IFN gamma production in the trigeminal ganglia (TG) of infected mice.

A simplified approach to construct infectious cDNA clones of a tobamovirus in a binary vector.

Infectious cDNA clones of RNA viruses are important tools to study molecular processes such as replication and host-virus interactions. However, the cloning steps necessary for construction of cDNAs of viral RNA genomes in binary vectors are generally laborious. In this study, a simplified method of producing an agro-infectious Pepper mild mottle virus (PMMoV) clone is described in detail.

Complete genome sequence of arracacha mottle virus.

Arracacha mottle virus (AMoV) is the only potyvirus reported to infect arracacha (Arracacia xanthorrhiza) in Brazil. Here, the complete genome sequence of an isolate of AMoV was determined to be 9,630 nucleotides in length, excluding the 3' poly-A tail, and encoding a polyprotein of 3,135 amino acids and a putative P3N-PIPO protein. Its genomic organization is typical of a member of the genus Potyvirus, containing all conserved motifs.

Complete genome sequence of Brugmansia suaveolens mottle virus, a potyvirus from an ornamental shrub.

Brugmansia suaveolens mottle virus (BsMoV) was the first potyvirus isolated from "angel trumpet" (Brugmansia suaveolens), described in Brazil. In this study, the complete nucleotide (nt) genome sequence of BsMoV was determined, and the deduced amino acid (aa) sequence was analyzed. The BsMoV RNA genome consists of 9870 nt without a poly-A tail, encoding a putative typical potyviral polyprotein of 3090 aa.