luteovirus

Luteovirus is a genus of plant viruses in the family Luteoviridae. Members of this genus are phloem-restricted and are typically transmitted by aphid vectors in a persistent, circulative manner. They infect a range of crop plants, including cereals and sugar beets, and are associated with yellowing, stunting, and reduced yields.

Structurally, luteoviruses are small, non-enveloped, icosahedral particles about 25–30 nanometers in diameter. Their genomes are single-stranded, positive-sense RNA of roughly 5.5 to 6 kilobases. The genome encodes a replication-associated protein, a movement or coat protein, and often a read-through protein that extends the coat protein and is essential for aphid transmission. Expression commonly involves subgenomic RNAs to produce some downstream gene products.

In plants, replication occurs in phloem-associated cells, followed by movement through the phloem sieve elements to achieve systemic infection. Viremia tends to be phloem-limited, which concentrates symptoms in the vascular tissue and can complicate detection.

Transmission relies on aphid vectors, with several common species capable of acquiring and transmitting luteoviruses. The transmission is persistent and circulative: the virus is acquired during feeding, circulates within the aphid, and is transmitted in subsequent feeds. Once acquired, the virus can be retained for the insect’s lifetime, enabling spread to new host plants.

Economically, luteoviruses can cause significant losses in cereal crops and sugar beets. Management emphasizes controlling aphid populations, deploying resistant cultivars where available, crop-free periods to disrupt vector cycles, and monitoring for outbreaks to reduce spread.

Representative species historically associated with this genus include Barley yellow dwarf virus (BYDV) and Beet western yellows virus (BWYV).