Cucumber mosaic virus

The cucumber mosaic virus (English Cucumber mosaic virus ) is a very common plant virus in horticulture. It infects cucumbers ( Cucumis ) and pumpkins (Cucurbita ), but also many other plants and is likely to spread worldwide. The isolates of cucumber mosaic virus can be assigned to two different serotypes, which also have different biological properties.

Morphology

The non-enveloped virions of Cucumber mosaic virus have a round shape and are about 29 nm in diameter in size. They consist of a capsid which is composed of 180 capsomeres (T = 3). These form at each of the twenty pages of the icosahedron hexons and the twelve corners Pentone; this structure from 32 parent units, behind which hides an icosahedral symmetry is called a quasi- icosahedron. The stability of the capsid is very dependent on the interaction with the packaged RNA molecules in all members of the genus Cucumovirus since the interaction of the capsomeres to each other is very weak. Thus, the capsids of cucumber mosaic virus decompose even in the presence of detergents or high salt concentrations, which are able to dissolve the protein-RNA interaction. Most strains of cucumber mosaic virus are unstable in the presence of Mg2 ions. All isolates are inactivated at 60 ° C.

Genome

The genome of cucumber mosaic virus is composed of three single-stranded RNA molecules having a positive polarity (RNA 1-3 ), and a tRNA -like, sub-genomic RNA, which is a copy of the second open reading frame of the RNA 3. The RNA strands each having a 1-3 - 5 ' Cap structure are not polyadenylated at its 5' end. The total size of the genome is approximately 8,000 nt that the RNA segments spread (RNA -1: 3357 nt, RNA -2: 3050 nt, RNA -3: 2216 nt).

Biological Properties

As host of the cucumber mosaic virus species from 85 different plant families are described, could experimentally infect over 1000 plant species. The virus overwinters primarily on perennial grasses that for aphids ( Aphidoidea ) are attractive in spring. The virus is then transmitted by aphids. Another transmission path passes over the cutting tools used in horticultural care measures. The virus is seed -transmitted.

On infested plants it causes mosaic symptoms, compressions and leaf deformations. The younger leaves may be chlorotic mottled to yellowish. The fruits are deformed and pied.

In the marketing standard for cucumbers (Council Regulation ( EEC) No 1677 /88) is set, that mosaic- infected cucumbers are classified as " not healthy " be excluded from marketing due to the possible further spread. In animals and humans, the virus neither an infection can trigger or cause disease.

Swell

• M. J. Roossinck et al. Bromoviridae Family. In: CM Fauquet, MA Mayo et al.: Eighth Report of the International Committee on Taxonomy of Viruses. London, San Diego, 2005, pp. 1049-1058 ISBN 0-12-249951-4
• Kenneth S. Smith: A Textbook of Plant Virus Diseases. 3rd edition, London 1972 ISBN 0-582-46624-5