The fungal transmitted viruses

Abstract

Most plant viruses are absolutely dependent on a vector for plant-to-plant spread. A number of different types of organisms work as vectors for different plant viruses. Plants, as sessile organisms, cannot transmit viruses except for some instances of seed or pollen transmission and the movement of plants resulting from human intervention. Thus, the great majority of plant viruses are dependent for their spread upon efficient transmission from plant to plant by specific vectors. Vector transmission is a specific event in the virus life cycle. Virus-encoded determinants specifically interact with the vector, thereby facilitating virus transmission, and various plant viruses utilize different, but specific, vectors to facilitate their spread. Different organisms such as insects, fungi, nematodes, animals and arthropods are recognized as vectors for various plant viruses, but in most cases, viruses of a given taxon have a specific type of vector (e.g., potyviruses are aphidtransmitted). These observations suggest that virus particles as well as vectors have specific sites that mediate their recognition. The coat protein (CP) of a plant virus has been shown to play an important role in transmission, and particular amino acids within the CP have been shown to be essential for this process (Brown et al. 1995; Campbell 1996; Gray 1996; Gray et al. 1999; Pirone and Blanc 1996). Recent work with Cucumber necrosis virus (CNV) has suggested that attachment of virions to vector zoospore is an important aspect of the transmission process.