Anti-PFBV polyclonal antibody

Two viruses, detected frequently in the Netherlands in pelargonium, were identified by serology and test plant reactions. Antisera were prepared and an ELISA procedure was developed to detect the viruses in pelargonium. One of the viruses, PFBV-N, proved to be pelargonium flower-break virus. With the antiserum to PFBV-N, it could be detected reliably throughout the year in Pelargonium zonale 'Springtime Irene'. The other virus, PLPV-N, was serologically closely related to pelargonium line pattern virus (PLPV) and to pelargonium ring pattern virus (PRPV), as were an old virus isolate from 'Saturnus', collected in the Netherlands in 1971 (L128), and PLPV isolates from Yugoslavia (PLPV-Y) and Denmark (PLPV-D). There were only minor differences in host-plant reactions between the virus isolates. Based on these tests, PLPV and PRPV are considered as isolates of the same virus, for which, for practical reasons, the name pelargonium line pattern virus is proposed. PLPV could be reliably detected by ELISA in P. zonale 'Springtime Irene' and 'Amanda' throughout the year with only a few exceptions. In Pelargonium peltatum 'Tavira', however, results were erratic due to uneven distribution of virus in the plant. Best results were obtained when petioles of fully expanded leaves were tested.

The complete nucleotide sequence of Pelargonium flower break virus (PFBV) has been determined. The genomic RNA is 3923 nucleotides (nt) long and contains five open reading frames (ORFs). The 5'-proximal ORF encodes a 27 kDa protein (p27) and terminates with an amber codon which may be read-through into an in-frame p56 ORF to generate a 86 kDa protein (p86) containing the viral RNA dependent-RNA polymerase motifs. Two small ORFs, located in the central part of the viral genome, encode polypeptides of 7 (p7) and 12 kDa (p12), respectively, which are very likely involved in virus movement. Interestingly, p12 presents a leucine zipper motif that has not been previously reported in related proteins. The 3'-proximal ORF encodes a 37 kDa capsid protein (CP). The p12 ORF is in-frame with the p86 ORF and a double read-through protein of 99 kDa (p99) may be produced. Amino acid sequence comparisons revealed that the proteins encoded by ORFs 2, 3 and 4 are more similar to the corresponding gene products of Carnation mottle virus than to those of other carmoviruses, whereas the p27 and the CP show higher identity with the equivalent proteins of Saguaro cactus virus. Phylogenetic analysis conducted with the different viral products confirmed the assignment of PFBV to the genus Carmovirus.