Virus evolution
Emergence of Plant RNA Viruses
Evolutionary Constraints on Emergence of Plant RNA Viruses
from Santiago F. Elena writing in Recent Advances in Plant Virology
Over the recent years, agricultural activity in many regions has been compromised by a succession of devastating epidemics caused by new viruses that switched host species, or by new variants of classic viruses that acquired new virulence factors or changed their epidemiological patterns. Although viral emergence has been classically associated with ecological change or with agronomical practices that brought in contact reservoirs and crop species, it has become obvious that the picture is much more complex, and results from an evolutionary process in which the main players are the changes in ecological factors, the tremendous genetic plasticity of viruses, the several host factors required for virus replication, and a strong stochastic component. A recent review puts the emergence of RNA viruses into the framework of evolutionary genetics and reviews the basic notions necessary to understand emergence, stressing that viral emergence begins with a stochastic process that involves the transmission of a pre-existing viral strain with the right genetic background into a new host species, followed by adaptation to the new host during the early stages of infection.
Further reading: Recent Advances in Plant Virology | Virology Publications
from Santiago F. Elena writing in Recent Advances in Plant Virology
Over the recent years, agricultural activity in many regions has been compromised by a succession of devastating epidemics caused by new viruses that switched host species, or by new variants of classic viruses that acquired new virulence factors or changed their epidemiological patterns. Although viral emergence has been classically associated with ecological change or with agronomical practices that brought in contact reservoirs and crop species, it has become obvious that the picture is much more complex, and results from an evolutionary process in which the main players are the changes in ecological factors, the tremendous genetic plasticity of viruses, the several host factors required for virus replication, and a strong stochastic component. A recent review puts the emergence of RNA viruses into the framework of evolutionary genetics and reviews the basic notions necessary to understand emergence, stressing that viral emergence begins with a stochastic process that involves the transmission of a pre-existing viral strain with the right genetic background into a new host species, followed by adaptation to the new host during the early stages of infection.
Further reading: Recent Advances in Plant Virology | Virology Publications
Plant Infection by Viruses
Population Dynamics and Genetics of Plant Infection by Viruses
from Fernando García-Arenal and Aurora Fraile writing in Recent Advances in Plant Virology
During the last thirty years, progress in understanding the mechanistic aspects of virus-plant interactions has been remarkable, notably in aspects such as genome replication, movement within the infected host or pathogenesis and resistance. Progress in understanding the population dynamics and genetics of plant infection by viruses has not been as great. However, understanding the kinetics of plant colonisation and the genetic structure of the within-host virus population is necessary for addressing many issues of plant-virus interaction and of virus evolution. The quantitative aspects of plant infection and colonisation by viruses were mostly addressed during the early period of plant virology, when many detailed studies were published that often incorporated mathematical modelling. These issues have not been thoroughly re-examined using molecular techniques. Recent work has focussed on the description of the genetic structure of the virus population at the organ and the plant level. Data suggest that in spite of huge fecundity, the effective numbers of the within-host virus population may be small due to severe population bottlenecks at each stage of plant infection and colonisation, which results in a spatially structured population.
Further reading: Recent Advances in Plant Virology | Virology Publications
from Fernando García-Arenal and Aurora Fraile writing in Recent Advances in Plant Virology
During the last thirty years, progress in understanding the mechanistic aspects of virus-plant interactions has been remarkable, notably in aspects such as genome replication, movement within the infected host or pathogenesis and resistance. Progress in understanding the population dynamics and genetics of plant infection by viruses has not been as great. However, understanding the kinetics of plant colonisation and the genetic structure of the within-host virus population is necessary for addressing many issues of plant-virus interaction and of virus evolution. The quantitative aspects of plant infection and colonisation by viruses were mostly addressed during the early period of plant virology, when many detailed studies were published that often incorporated mathematical modelling. These issues have not been thoroughly re-examined using molecular techniques. Recent work has focussed on the description of the genetic structure of the virus population at the organ and the plant level. Data suggest that in spite of huge fecundity, the effective numbers of the within-host virus population may be small due to severe population bottlenecks at each stage of plant infection and colonisation, which results in a spatially structured population.
Further reading: Recent Advances in Plant Virology | Virology Publications