Characterization of a Zucchini Yellow Mosaic Virus Isolate with a Deficient Helper Component

Potyviral HC-Pro: a multifunctional protein

“…Potyvirus isolates that are defective in aphid transmission due to alterations in HC-Pro have been described (Kassanis & Govier, 1971 b;Thombury et al, 1990;Lecoq et al, 1991). The first attempt to unravel the reason for this defect at the molecular level was undertaken with an HC-defective strain of PVY designated PVC.…”

Switches in the mode of transmission select for or against a poorly aphid-transmissible strain of potato virus Y with reduced helper component and virus accumulation

“…Xanthi) plants infected with each virus isolate were used as source of virus for plant-toplant aphid transmissions as described (Lecoq et al, 1991).…”

“…This deficiency could be due to mutations either in HC-Pro or in the N-terminal part of the CP. Isolates defective in transmission due to alterations in HC-Pro have been described (Kassanis & Govier, 1971;Lecoq et al, 1991) and the corresponding HC-Pro genes sequenced (Thornbury et al, 1990;Granier et al, 1993). Comparisons of the predicted amino acid sequences of HC-Pro revealed two types of amino acid change leading to the poorly aphid-transmissible (PAT) phenotype.…”

Mutations in the helper component protease gene of zucchini yellow mosaic virus affect its ability to mediate aphid transmissibility

“…Lecoq et al (1991 b) have described a mild and very poorly aphid-transmissible ZYMV strain (ZYMV-WK) which is derived from a severe and helper-deficient isolate (ZYMV-PAT) (Lecoq et al, 1991a). Similarly to PVC, the helper-deficient ZYMV may be transmitted efficiently by aphids if coinfected with another potyvirus (Lecoq et al, 1991 b), or if its virions are mixed with an HC deriving from another isolate of ZYMV (Lecoq et al, 1991a). In the present study, the HC-Pro gene of a helper-deficient …”