Luteovirus

Description and Significance
Luteovirus is one of three genera in the luteoviridae family whose primary hosts are plants. The genera also contains the polerovirus and enamovirus. The geographical distribution of luteovirus is widespread, with the virus primarily infecting plants via transmission by aphid vectors. The virus only replicates within the host cell and not within the vector. The name 'luteovirus' arises from the Latin luteus, which is translated as 'yellow'. Luteovirus was given this name due to the symptomatic yellowing of the plant that occurs as a result of infection.

Morphology and Genome Structure
Luteovirus is a group IV virus according to the Baltimore classification of viruses. Each virion contains a single strand of (+) sense RNA. The genome is non-segmented, linear and between 5300 and 5900 nucleotides long. Notably, lutovirus has two 5'  open reading frames (ORFs) which are located  upstream of the coat protein. One such ORF encodes an RNA-dependant RNA polymerase. Several other ORFs are present at the 3' terminus and are expressed from subgenomic RNA. Luteovirus also lacks polyadenylation at the 3' terminus.

Virions are non-enveloped, icosahedral structures, ranging from 25-30nm in diameter with 32 capsomeres in each nucleocapsid. The nucleic acid content is around 28%.