Reasons for the low accumulation level of aphid transmission factor protein in infected leaves with an aphid-non-transmissible cauliflower mosaic virus isolate, CM1841

Abstract

The synthesis and accumulation of aphid transmission factor protein (p18) in cauliflower mosaic virus (CaMV)-infected turnip protoplasts were examined in time course and pulse-labelling experiments, comparing an aphidnon-transmissible isolate (CM1841) with an in vitro recombinant aphid-transmissible CaMV (CMBX) generated from the CM1841 isolate. There was little difference in the synthesis and accumulation of p18 between CM1841-and CMBX-infected protoplasts. When the accumulation of p18 in infected leaves was monitored from 3 to 28 days post-symptom emergence (p.e.) by Western blotting, the amount of p18 accumulated in CM 1841-infected leaves continuously decreased from 3 days p.e. throughout the experimental period, whereas the amount of p18 in CMBX-infected leaves was lowest at 3 days p.e. and increased thereafter. These results suggested that CM 1841 differed from CMBX not in the synthesis of p18 but in the stability of p18 in infected leaves.

Eucaryotic initiation factor 4B controls eIF3-mediated ribosomal entry of viral reinitiation factor

“…Proteins were separated on 12.5% polyacrylamide gels and transferred to nitrocellulose membranes by electroblotting (1 h, 1 mA/cm 2 gel). TAV and eIF3b in sucrose density gradient fractions were detected using a purified polyclonal rabbit anti‐TAV antiserum (Nakayashiki et al 1993) or an anti‐human eIF3b (PRT1) antiserum (Lin et al , 2001). In plant protoplast extracts, TAV and its mutants were detected using rabbit anti‐TAV antiserum (De Tapia et al , 1993).…”

Requirement of Cauliflower Mosaic Virus Open Reading Frame VI Product for Viral Gene Expression and Multiplication in Turnip Protoplasts

“…Immunofluorescent staining and Western blotting. Antibodies to Pl, P2, P3, P4 and P6 were raised against the fusion proteins of viral gene products and bacterial protein A as described previously (27,37,38,48). Antibody to P5 (41) was a generous gift of Dr. Thomas Hohn.…”

Mutations within A 35 amino acid region of P6 influence self-association, inclusion body formation, and Caulimovirus infectivity

“…These electron-lucent IBs are essential for insect vectoring of CaMV and have been termed Transmission Bodies (TBs). TBs are not required for viral infection within a plant and strains of CaMV exist that either lack most of the P2 coding sequence or contain gene II mutations resulting in P2 proteins incapable of forming native TBs (Howarth et al, 1981; Khelifa et al, 2007; Nakayashiki et al, 1993). For example, CaMV isolate CM1841 harbors a G94R mutation in gene II that has been shown to cause production of aberrant TBs in other CaMV strains and so may account for the failure of this virus to be aphid-transmissible.…”