Viruses and virus‐like pathogens transmitted by zoosporic fungi¹

Abstract

The viruses and virus‐like pathogens transmitted by zoosporic fungi are reviewed. The nine furoviruses (and possible members of the group), with labile rod‐shaped particles, have nearly all been shown to be transmitted by plasmodiophoromycete vectors. As they have been reviewed extensively elsewhere, they are covered only briefly; important examples are beet necrotic yellow vein furovirus and potato mop‐top furovirus. Five viruses with filamentous particles, tentatively recognized as poty viruses, are transmitted by Polymyxa graminis. Within this group, wheat yellow mosaic virus should be considered to include wheat spindle streak mosaic virus, while the M and NM forms of barley yellow mosaic virus, the best known members of the group, should probably be regarded as distinct viruses. Chytrids (especially Olpidium brassicae) transmit a variety of viruses in different groups (e.g. tobacco necrosis necrovirus, lettuce big‐vein virus, melon necrotic spot carmovirus, red clover necrotic mosaic dianthovirus). Finally, several diseases caused by uncharacterized pathogens appear to be transmitted by O. brassicae: freesia leaf necrosis, lettuce ring necrosis, pepper yellow vein, watercress chlorotic leaf spot.

The complete nucleotide sequence of RNA 1 of a German isolate of barley yellow mosaic virus and its comparison with a Japanese isolate

“…This classification was based on their particle morphology and the induction of characteristic cytoplasmic cylindrical inclusion bodies in the cereal hosts (Hibino et al, 1981;Ebrahim-Nesbat & Zerlik, 1984;Huth et al, 1984). However, in contrast to potyviruses this group of viruses has a genome consisting of two RNA species (Huth, 1988;Usugi et al, 1989) and is transmitted by the fungus Polymyxa graminis (Adams et al, 1989;Brunt, 1989). In addition, most of these fungus-transmitted viruses are serologically related to each other but most do not show any serological relationship to potyviruses transmitted by other vectors (Huth et al, 1984;Ehlers & Paul, 1986;Adams et al, 1987;Usugi et al, 1989).…”

Fungally-transmitted Rod-shaped Plant Viruses: Biology, Transmission and Molecular Pathology

“…Plasmodiophorid Fungi: Taxonomy and Life Cycle: Fungi, known to transmit furoviruses, are zoosporic, obligate parasites of plant roots and belong to the class plasmodiophoromycetes, subdivision Mastigomycotina and division Amastigomycota (Adams, 1991a;Brunt, 1989). P. graminis and P. betae, generally not thought to be pathogenic to their hosts, are morphologically indistinguishable, but have different host ranges (Barr, 1979).…”

Transmission of plant viruses by fungi

“…While this is a small number compared to those known to have arthropod vectors it includes the agents of several important diseases. There are recent reviews of the diseases caused by such viruses and of the molecular biology of the betterknown ones (Fraenkel-Conrat, 1988;Brunt & Shikata, 1987;Cooper & Asher, 1988;Brunt, 1989;Brunt & Richards, 1989;Hiruki, 1989). This review examines what is known about the association between fungally-transmitted viruses and their vectors, and the consequent mechanisms of transmission.…”