结构与功能

The ability to combine nucleic acid hybridisation or immunospecific reactions with structural and ultrastructural analysis of virus-infected tissues has provided the opportunity to resolve the spatial details of infection with respect to the production of virus-specific pr ...

The interaction between viral polymerases and their cognate RNAs is vital to regulate the timing and abundance of viral replication products. Despite this, only minimal detailed information is available for the interaction between viral polymerases and cognate RNAs. We study the bio ...

Small RNAs such as small interfering RNAs (siRNAs) and microRNAs (miRNAs) play crucial roles in establishing general host defense mechanisms against viral infections in plants and the development of disease symptoms. Understanding these fundamental processes requires the sen ...

During their infection in plants, viruses can form double stranded (ds) RNA structures. These dsRNAs can be recognized by plants as “aberrant” signals and short interfering RNA (siRNA) molecules of 19–25 nt will be produced with sequences derived from the viral source. Knowledge about antiv ...

Analysis of viral RNA encapsidation assay provides a rapid means of assaying which of the progeny RNA are competent for packaging into stable mature virions. Generally, a parallel analysis of total RNA and RNA obtained from purified virions is advisable for accurate interpretation of the re ...

Single-stranded RNA plant viruses not only code for viral proteins within their RNA genomes, they often maintain elaborate RNA secondary structures. These structures can be integral to a variety of viral processes, such as viral translation, genome replication, subgenomic mRNA trans ...

Positive-strand RNA viruses often use noncanonical strategies to usurp the host translational machinery for their own benefit. These strategies have been analyzed using transient expression assays in the absence of replication, with reporter genes replacing viral genes. A sensi ...

Replication of the viral RNA genome performed by the viral replicase is the central process during the viral infection cycle (Nagy and Pogany, see earlier chapter four). Most RNA viruses assign one or more proteins translated from their own genomes for assembling the viral replicase complex, w ...

Plant RNA viruses exploit nonorthodox strategies, such as the use of internal ribosomal entry sites (IRES), to express multiple genes from a single RNA species. IRES elements have been reported in tobacco etch virus (TEV), crucifer infecting tobamovirus (crTMV), hibiscus chlorotic ring ...

The genomes of many plant viruses contain translation-enhancing sequences that allow them to compete successfully with host messenger RNAs for the translation machinery. Identification of translation enhancer elements is valuable, both to gain understanding of virus gene exp ...

RNA–protein interactions control viral RNA replication, transcription, translation, and particle assembly. Progress toward understanding the functional significance of RNA–protein complexes in the viral life cycle is hindered by the lack of high resolution structural inf ...

Most plant viruses move between plant cells with the help of their movement proteins (MPs). MPs are multifunctional proteins, and one of their functions is almost invariably binding to nucleic acids. Presumably, the MP—nucleic acid interaction is directly involved in formation of nucleo ...

Movement proteins (MPs) are virally encoded factors that mediate transport of viral nucleic acid between plant cells. Many MPs are able to move between cells themselves. This feature serves as the basis for evaluation of the transport activity of individual MPs. MPs are transiently express ...

RNA silencing is an evolutionarily conserved system that functions as an antiviral mechanism in higher plants and animals. To counteract RNA silencing, viruses evolved silencing suppressors that interfere with siRNA guided RNA silencing pathway. We used the heterologous Drosop ...

Posttranslational modification of proteins is a key regulatory mechanism in a variety of cellular processes. This chapter outlines the concepts and methods used to investigate protein phosphorylation and its physiological relevance during plant virus infection. Rather than p ...

Replication of the genome of positive-strand RNA plant viruses takes place in membrane-bound complexes that contain viral replicase proteins, viral RNA, and host proteins. Many viral replicase proteins play a crucial role in the assembly of replication complexes at intracellular me ...

In terms of functional genomics research, Nicotiana benthamiana, more so than other model plants, is highly amenable to high-throughput methods, especially those employing virus-induced gene silencing and agroinfiltration. Furthermore, through recent and ongoing sequenc ...

This chapter introduces an efficient and accurate site-directed mutagenesis protocol, which allows the color selection of mutants through the simultaneous activation or deactivation of the α-peptide of β-galactosidase. It uses doublestranded plasmid DNA as the mutational te ...

Maize streak virus (MSV) genome has four open reading frames. C1 and C2 encoded by the complementary sense are required for virus replication, while V1 and V2 encoded by virion sense are required for infectivity. V1 encodes movement protein (MP), while V2 encodes coat protein (CP). Deletion or mutat ...

Yeast two-hybrid systems are powerful tools to identify novel protein–protein interactions and have been extensively used to study viral protein interactions. The most commonly used systems are GAL4-based and LexA-based systems. Over the last decade, a range of modifications and imp ...