||Positive-Sense Viral RNA -- Infection by and Uncoating of Virus Particles -- Replication of Plus-Sense Viral RNA -- RNA-Dependent RNA Polymerases and Replicases -- Helicases -- Proteinases -- Subgenomic RNAs -- Gene Expression -- Assembly of Virus Particles -- Host Factors and Virus Multiplication. Multiplication is the basic biological function of all organisms and is dependent upon replication of genomes. This is also true of plant viruses even though they possess a minimum of essential genetic information. Phylogenetically, replication-associated genes constitute the core elements of RNA virus genomes while other gene modules are considered as accessory elements. However, the biochemical studies on plant virus RNA replication were in their infancy even in 1999-2000. The picture has improved much since structural and sequence requirements of viral RNA replication, and synthesis are beginning to be understood, primarily because of the genetic, molecular, biochemical, and enzymatic studies conducted during the last six years. Certain virus-encoded essential proteins, nucleotide sequence motifs, and RNA secondary structures are central to virus RNA replication, which has a number of stages. Each stage is a complex phenomenon requiring specific factors and conditions. All this has generated much new information so that replication of plus-sense RNA plant viruses has now emerged as a rapidly developing field. However a lot of distance still has to be covered and traversing this distance could prove difficult because no one organised corpus of knowledge is available. Hopefully, this book fills the niche and generates understanding of multiplication of plus-sense RNA plant viruses, especially at molecular level. Nearly all the information on various aspects of plant virus multiplication has been collected, collated, and organized in eleven chapters spanning 332 pages so that this book comprehensively covers all facets of multiplication of plus-sense RNA plant viruses. No such book has been published so far.