Genome sequence of a recombinant brassica yellows virus infecting Chinese cabbage

Abstract

RNA from a Chinese cabbage plant (Brassica campestris ssp. pekinensis) showing leaf malformation and mottling was labeled and hybridized to a DNA chip capable of detecting plant viruses and viroids. Probes specific for beet mild yellowing virus (BMYV) and beet western yellows virus (BWYV) yielded positive results, suggesting that the plant was infected by a polerovirus. Primers designed from the sequences of the positive probes were used to amplify and sequence one portion of the viral genome. This sequence showed a 90 % or greater identity to several poleroviruses, including BMYV, BWYV, beet chlorosis virus (BChV) and turnip yellows virus (TuYV). The complete genome sequence of the Chinese cabbage-infecting polerovirus consisted of 5,666 nt and was most closely related to brassica yellows virus (BrYV; 94 % identity). The virus was named BrYV-Cheongsong (BrYV-CS). However, ORF3, ORF4 and the 5' half of ORF5 of BrYV-CS were more closely related to those of TuYV, BWYV, BChV and BMYV than to those of BrYV. Interestingly, a recombination event (positions 3531-4819 in BrYV-CS) was detected when this sequence was aligned with those of BrYV and TuYV. This region showed the highest sequence identity to that of TuYV (94 % identity) and had greater than 93 % identity to those of BWYV, BChV and BMYV, but it shared only 81 % identity with that of BrYV. Taken together, the genomes of BrYV-CS and BrYV are closely related. However, the structural genes in the 3' half of the genome of BrYV-CS are more closely related to those of other poleroviruses.

Simultaneous detection and differentiation of three genotypes of Brassica yellows virus by multiplex reverse transcription-polymerase chain reaction

“…oleifera ). It can cause yellowing and leaf malformation or mottling symptoms on cruciferous crops [1, 2]. …”

Synergistic infection of BrYV and PEMV 2 increases the accumulations of both BrYV and BrYV-derived siRNAs in Nicotiana benthamiana

“…Brassica yellows virus (BrYV, a provisional name) is a tentative polerovirus that distributes in China, South Korea, and Japan36373839. BrYV infects a wide range of cruciferous crop plants36 and tobacco40.…”

Host range and molecular analysis of Beet leaf yellowing virus, Beet western yellows virus‐JP and Brassica yellows virus in Japan

“…However, those viruses showed much lower levels of sequence identity (56–68%) with the BrYV group, which had much higher identity (90%) within isolates. As an exception, P5 sequences of BrYV‐CS and BWYV‐BJA (and BWYV‐BJB) have low levels of identity (41–42%) with BrYV and BWYV (Zhou et al ., ; Lim et al ., ), which were excluded from the P5 tree.…”

“…It should be noted in particular that, within the P5 domain, whereas the N‐terminal region is highly conserved, the C‐terminal region, which has a role for facilitating long‐distance virus movement in phloem tissue, is more variable (Peter et al ., ). Indeed, it is of interest that P5‐recombinant viruses such as BWYV‐BJA and ‐BJB from sugar beet (Zhou et al ., ), BrYV‐CS from Chinese cabbage (Lim et al ., ) and BrYV‐NtabQJ from tobacco (Wang et al ., ) that were generated by recombination events within the P5 domain, have been reported in Asia. Further work will be needed to clarify to what extent the sequences of the P5 C‐terminal region have a role in host range determination (host adaptation) of poleroviruses in nature.…”

“…These four species of poleroviruses (the so‐called BWYV‐like group) are closely related serologically to one another, transmitted efficiently by the green peach aphid Myzus persicae , and have been reported mainly from Europe and the USA (Stevens et al ., , ,b; Graichen & Rabenstein, ; Beuve et al ., ). Recently, nucleotide sequences of a TuYV‐like virus that was named Brassica yellows virus (BrYV) have been reported from Asia (Xiang et al ., ; Zhang et al ., ; Lim et al ., ).…”