Molecular Analysis of ORF6, ORF7 and ORF8 of Beet yellows virus Iranian

Tabejamaat, Z., A. Massah and A. Ahoonmanesh. 2013. Molecular Analysis of ORF6, ORF7 and ORF8 of Beet yellows virus Iranian. Journal of Phytopathology, 161: 577-578.

Beet yellows virus (BYV), a member of the Closteroviridae

family, is one of the most important sugar beet

yellowing viruses. The nine ORFs of BYV genome

encode different proteins required for BYV life cycle.

We sequenced a part of the genome of BYV Iranian

isolate consisting of ORF6, ORF7 and ORF8. The primer

pair BYVA/Z was used for amplification of this

region in RT-PCR. The amplicon (1615 bp) was

cloned and sequenced. Comparisons showed the amplified

segment is corresponding to ORF6, ORF7 and

ORF8 of BYV genome encoding coat protein, p20 and

p21 proteins, respectively. The ORF7 of BYV Iranian

isolate overlaps with ORF6 and ORF8 in four and 26

nucleotides at 5
and 3
ends, respectively. The ORF7

of Iranian isolate of BYV was sequenced completely.

However, approximately 24 nt. from the beginning of

ORF6 and 23 nt. from end of ORF8, including the

stop codon, were not determined. ORF6, ORF7 and

ORF8 showed the highest similarity at nucleotide

(98.3, 99.4 and 99.2%) and amino acid (97.4, 98.9 and

100%) sequence levels, with BYV Ukraine isolate.

Phylogenetic analysis of the deduced amino acid

sequences of ORF6, ORF7 and ORF8 revealed closer

relationship of Iranian isolate of BYV with BYV

Ukraine isolate than other BYV isolates available at

GenBank.