Helenium virus Y

HVY belongs to the potyvirus genus.[2] The potyvirus genus is currently the largest of the plant virus groups, creating an optimal intracellular environment for viral translation and replication.[3] It is one of two strains to specifically affect Helenium hybrids, the other strain being Helenium virus S, a carlavirus. The host of HVY is the Helenium amarum hybrids as well as certain breeds of Chenopodium. While the hybrids can be affected by other plant viruses such as the tobacco ringspot virus, HVY tends to primarily affect the Helenium amarum hybrids. Symptoms of infection include discoloration of the flowers, leaf distortion, leaf mosaic, ringspots on leaves, growth reduction of leaves and flower heads, and stunting of development of the internodes. Some cases of HVY infections, such as infections in C. quinoa, G. globosa, C. amaranticolor, and C. album have led to chlorotic local lesions.[2]

HVY is mechanically transmitted from plant to plant, often through hosts like aphids.[4] Like many potyviruses, HVY replication occurs in the cytoplasm, nuclei, chloroplasts, and the Golgi apparatus.[5] Potyviruses induce the intracellular formation of 3D cytoplasmic inclusions within affected plants, which are seen as pinwheels in transverse section and as bundles in longitudinal section. HVY induces typical pinwheels and bundles.[2] HVY can be easily prevented in Helenium hybrids through disinfectants and antisera.

Potyvirus virions of HVY consist of flexuous particles with a length of 721 nm.[2] The infectivity dilution endpoint of HVY is 10⁻⁴ and the thermal inactivation point is between 55 and 60 C.[2]