Virus-induced flowering-a tool for cereals

Plant viruses have long been recognized as valuable tools for plant molecular biology, and they continue to provide a rapid way to transiently manipulate gene expression for basic science and more applied purposes. The advantages of virus-based approaches for manipulating gene expression are several: promoters, especially those driving expression of coat protein genes, are typically strong and active in many/most plant tissues; many replicate autonomously to form multicopy replicons; and systemic movement allows inoculation in one tissue to spread throughout the whole organism. Disadvantages can include a narrow host range such that a virus conveniently infecting one species will be non-infectious on another; compact genomes and packaging constraints can limit insert sizes; the extent of systemic spread and viral titer in recipient tissues can be patchy; and rapid replication and propensity for recombination can lead to loss of engineered sequences as the virus reverts to the most efficient form for replication and spread.