The Amino-Proximal Region of the Coat Protein of Cucumber Vein Yellowing Virus (Family Potyviridae) Affects the Infection Process and Whitefly Transmission

Abstract

Most plant viruses rely on vector transmission for their spread and specific interactions between vector and virus have evolved to regulate this relationship. The whitefly Bemisia tabaci- transmitted cucumber vein yellowing virus (CVYV; genus Ipomovirus, family Potyviridae) is endemic in the Mediterranean Basin, where it causes significant losses in cucurbit crops. In this study, the role of the coat protein (CP) of CVYV for B. tabaci transmission and plant infection was investigated using a cloned and infectious CVYV cDNA and a collection of point and deletion mutants derived from this clone. Whitefly transmission of CVYV was abolished in a deletion mutant lacking amino acids in position 93–105 of the CP. This deletion mutant caused more severe disease symptoms compared to the cDNA clone representing the wild-type (wt) virus and movement efficiency was likewise affected. Two virus mutants carrying a partially restored CP were transmissible and showed symptoms comparable to the wt virus. Collectively, our data demonstrate that the N-terminus of the CVYV CP is a determinant for transmission by the whitefly vector and is involved in plant infection and symptom expression.

In-silico comparative modeling and interaction studies of PRSV proteins - Accelerated towards dissection of structure based evolutionary divergence and functional interaction of virus within the host

“…The alignment of amino acid sequences of CP from different inter geographical regions using Constraint-based Multiple Alignment Tool (COBALT-NCBI) predicted the intrinsically disordered regions towards the N-terminal region presenting high sequence variation and high flexibility. These finding complies with the reports suggesting high polymorphism in the Nterminal region associated with functional versatility leads to multiple interactions [37].…”

“…The core domain has been reported to be critical for RNA encapsidation and virion formation [40,46]. Henceforth, mutational alterations in specific parts may leads to differential changes in virus properties [37].…”

“…As the high diversity in N-terminal region of CVYV and Cassava brown streak viruses seem to be determinant of whitefly transmission, however the deletion of 13aa in N-terminus would leads to the loss of transmission [37].…”

“…The core domain has been reported to be critical for RNA encapsidation and virion formation [40,46]. Henceforth, mutational alterations in specific parts may leads to differential changes in virus properties [37]. As the high diversity in N-terminal region of CVYV and Cassava brown streak viruses seem to be determinant of whitefly transmission, however the deletion of 13aa in N-terminus would leads to the loss of transmission [37].…”

High molecular diversity of full-length genome sequences of zucchini yellow fleck virus from Europe

“…Pairwise comparisons of the CP sequence showed that PV-1263 from France was the most divergent virus, with ~87-90% aa sequence identity to the other As has been observed in the CPs of other potyviruses [33][34][35], most of the divergence was observed in the N-terminal region of the protein, at positions 13-15 and 24-32, while aa residues at positions 121 to 277 were identical among all sequences; a deletion of 3 aa at position 29-31 was unique to PV-1263. A phylogenetic analysis with other CP sequences available in the NCBI/GenBank database showed that the Greek isolates from squash grouped in a cluster with the isolate from Apulia/Greece, while the CP of the DSMZ accessions from Sicily and Sardinia and two sequences from melon collected in 2006 in Sicily [11] formed a separate sequence cluster (Supplementary Fig.…”