Virus Resistance
Resistance to Viruses in Plants
Sustainable Management of Plant Resistance to Viruses
from Benoît Moury, Alberto Fereres, Fernando García-Arenal and Hervé Lecoq writing in Recent Advances in Plant Virology
Although viruses are among the parasites which induce the most severe damages on cultivated plants, few control methods have been developed against them. Notably, no curative methods can be applied against virus diseases in crops. In view of this major economic problem, the development of resistant cultivars has become a critical factor of competitiveness for breeders. However, plant - virus interactions are highly dynamic and the selective pressure exerted by plant resistance frequently favours the emergence of adapted virus populations. Given the scarcity of resistance genes, there is consequently an urgent need to increase the sustainability of these genetic resources. A recent publication reviews the biological mechanisms which allow the emergence of virus populations adapted to plant resistances and how we can use this knowledge to explain the relative durability of different resistance genes, to built predictors of resistance durability and to combine the use of resistances with other control methods to increase their sustainability.
Further reading: Recent Advances in Plant Virology | Virology Publications
from Benoît Moury, Alberto Fereres, Fernando García-Arenal and Hervé Lecoq writing in Recent Advances in Plant Virology
Although viruses are among the parasites which induce the most severe damages on cultivated plants, few control methods have been developed against them. Notably, no curative methods can be applied against virus diseases in crops. In view of this major economic problem, the development of resistant cultivars has become a critical factor of competitiveness for breeders. However, plant - virus interactions are highly dynamic and the selective pressure exerted by plant resistance frequently favours the emergence of adapted virus populations. Given the scarcity of resistance genes, there is consequently an urgent need to increase the sustainability of these genetic resources. A recent publication reviews the biological mechanisms which allow the emergence of virus populations adapted to plant resistances and how we can use this knowledge to explain the relative durability of different resistance genes, to built predictors of resistance durability and to combine the use of resistances with other control methods to increase their sustainability.
Further reading: Recent Advances in Plant Virology | Virology Publications
Virus Resistance in Plants
Advanced Breeding for Virus Resistance in Plants
from Alain Palloix and Frank Ordon writing in Recent Advances in Plant Virology
Breeding for virus resistance was successful in the past years using conventional breeding methods since many virus resistant cultivars have been delivered for a wide range of crops. Genome mapping provided molecular markers for many resistance loci (i.e., major genes or Quantitative Trait Loci) that were introgressed into cultivars e.g., through backcross breeding schemes. Molecular mapping also delivered much information on the genomic architecture of polygenic and quantitative resistances. However, marker assisted selection for such complex traits is difficult so that the combination of quantitative resistance factors from multiallelic origins commonly relies on sophisticated phenotyping procedures. The cloning of resistance genes and the rapid development of high throughput molecular technologies increased the access to functional markers and multiallelic markers, promoting the applicability of marker assisted selection for complex traits at the whole genome scale in the near future. In parallel, the advances in the identification of molecular determinants of plant/virus interactions and in genetics and evolution of virus populations provide new selection criteria for breeders to choose the most durable resistance genes and gene combinations, so that breeding for durable virus resistance becomes an accessible quest.
Further reading: Recent Advances in Plant Virology | Virology Publications
from Alain Palloix and Frank Ordon writing in Recent Advances in Plant Virology
Breeding for virus resistance was successful in the past years using conventional breeding methods since many virus resistant cultivars have been delivered for a wide range of crops. Genome mapping provided molecular markers for many resistance loci (i.e., major genes or Quantitative Trait Loci) that were introgressed into cultivars e.g., through backcross breeding schemes. Molecular mapping also delivered much information on the genomic architecture of polygenic and quantitative resistances. However, marker assisted selection for such complex traits is difficult so that the combination of quantitative resistance factors from multiallelic origins commonly relies on sophisticated phenotyping procedures. The cloning of resistance genes and the rapid development of high throughput molecular technologies increased the access to functional markers and multiallelic markers, promoting the applicability of marker assisted selection for complex traits at the whole genome scale in the near future. In parallel, the advances in the identification of molecular determinants of plant/virus interactions and in genetics and evolution of virus populations provide new selection criteria for breeders to choose the most durable resistance genes and gene combinations, so that breeding for durable virus resistance becomes an accessible quest.
Further reading: Recent Advances in Plant Virology | Virology Publications
Plant Resistance to Viruses
Plant Resistance to Viruses Mediated by Translation Initiation Factors
from Olivier Le Gall, Miguel A. Aranda and Carole Caranta writing in Recent Advances in Plant Virology
Host resistance to viruses can show dominant or recessive inheritance. Remarkably, recessive resistance genes are much more common for viruses than for other plant pathogens. Recessive resistances to viruses are especially well documented within the dicotyledons, and have been described for various viruses that belong to very different viral genera, although clearly they predominate among viruses belonging to the genus Potyvirus. The elucidation of the molecular nature of this particular class of resistance genes is recent, but has so far only revealed a group of proteins linked to the translation machinery, chiefly the eukaryotic translation initiation factors (eIF) 4E and 4G. There are specific features and mechanisms of eIF4E- and 4G-mediated resistances to potyviruses and viruses belonging to other genera, such as carmoviruses.
Further reading: Recent Advances in Plant Virology | Virology Publications
from Olivier Le Gall, Miguel A. Aranda and Carole Caranta writing in Recent Advances in Plant Virology
Host resistance to viruses can show dominant or recessive inheritance. Remarkably, recessive resistance genes are much more common for viruses than for other plant pathogens. Recessive resistances to viruses are especially well documented within the dicotyledons, and have been described for various viruses that belong to very different viral genera, although clearly they predominate among viruses belonging to the genus Potyvirus. The elucidation of the molecular nature of this particular class of resistance genes is recent, but has so far only revealed a group of proteins linked to the translation machinery, chiefly the eukaryotic translation initiation factors (eIF) 4E and 4G. There are specific features and mechanisms of eIF4E- and 4G-mediated resistances to potyviruses and viruses belonging to other genera, such as carmoviruses.
Further reading: Recent Advances in Plant Virology | Virology Publications