The secondary structure of RNA in particles of two plant viruses with helical symmetry (tobacco mosaic virus (TMV) and potato virus X (PVX)) was studied by determining their RNA extinction spectra in situ. The true values of extinction of light-scattering virus suspensions were calculated by extrapolation. To determine the degree of hyperchromicity of internal RNA, the spectra of suspensions of...

In comparison to single infections, co-infection of Nicotiana benthamiana with Potato virus X (PVX) and Potato virus Y (PVY) or Plum pox virus (PPV), resulted in increased systemic symptoms (synergism in pathology). Previous studies have shown that virus infections affected the accumulation of various microRNAs (miRNAs) and miRNA target genes. Our studies revealed that double infection by PVX a...

Alternanthera mosaic virus (AltMV) triple gene block 3 (TGB3) protein is involved in viral movement. AltMV TGB3 subcellular localization was previously shown to be distinct from that of Potato virus X (PVX) TGB3, and a chloroplast binding domain identified; veinal necrosis and chloroplast vesiculation were observed in Nicotiana benthamiana when AltMV TGB3 was over-expressed from PVX. Plants wit...

The eukaryotic translation elongation factor 1 (eEF1) has two components: the G-protein eEF1A and the nucleotide exchange factor eEF1B. In plants, eEF1B is itself composed of a structural protein (eEF1Bγ) and two nucleotide exchange subunits (eEF1Bα and eEF1Bβ). To test the effects of elongation factors on virus infection, we isolated eEF1A and eEF1B genes from pepper (Capsicum annuum) and supp...

Agroinfiltration and PVX agroinfection are two efficient transient expression assays for functional analysis of candidate genes in plants. The most commonly used agent for agroinfiltration is Agrobacterium tumefaciens, a pathogen of many dicot plant species. This implies that agroinfiltration can be applied to many plant species. Here, we present our protocols and expected results when applying...

The genes encoding the helper component (HC) proteins of two strains of Potato virus Y (PVY) were cloned and the proteins expressed from a vector derived from Potato virus X (PVX). The expressed HC contained six N-terminal histidine residues to facilitate purification by metal affinity chromatography. Approximately 2-4 microg/g of purified HC was obtained from leaves of Nicotiana benthamiana pl...

Plant microRNAs (miRNAs) play pivotal roles in many biological processes. Although many miRNAs have been identified in various plant species, the functions of these miRNAs remain largely unknown due to the shortage of effective genetic tools to block their functional activity. Recently, miRNA target mimic (TM) technologies have been applied to perturb the activity of specific endogenous miRNA o...

The genomic RNA of the potato virus X (PVX) strain HB, isolated in Bolivia and able to overcome all known resistance genes, has been cloned and sequenced. The PVXHB RNA sequence is 6432 nucleotides long and contains, similarly to the RNAs of other PVX strains, five open reading frames encoding proteins of M(r)s 165.1K, 24.5K, 12.4K, 7.6K and 25.1K (coat protein), respectively. Multiple amino ac...

Infection with Potato virus X (PVX) in Nicotiana benthamiana plants leads to increased transcript levels of several stress-related host genes, including basic-region leucine zipper 60 (bZIP60), SKP1, ER luminal binding protein (BiP), protein disulfide isomerase (PDI), calreticulin (CRT), and calmodulin (CAM). bZIP60 is a key transcription factor that responds to endoplasmic reticulum (ER) stres...

Most RNA viruses remodel the endomembrane network to promote virus replication, maturation, or egress. Rearrangement of cellular membranes is a crucial component of viral pathogenesis. The PVX TGBp2 protein induces vesicles of the granular type to bud from the endoplasmic reticulum network. Green fluorescent protein (GFP) was fused to the PVX TGBp2 coding sequence and inserted into the viral ge...