Detection and Characterization of a Distinct Type of Beet Necrotic Yellow Vein Virus RNA 5 in a Sugarbeet Growing Area in Europe

Abstract

A fifth beet necrotic yellow vein virus (BNYVV) RNA species has been detected in Europe in sugarbeet infected with P-type BNYVV. Very little sequence variation was found between two European sources of this RNA 5*, but considerable differences were detected between these two European sources on the one hand and the four Japanese sources recently analysed by Kiguchi et al. on the other. The BNYVV RNA 5-encoded 26 K proteins share a stretch of six amino acids (FRGPGN) with the BNYVV RNA 3-encoded 25 K protein which may be of interest in view of the reported interactions between the two RNAs in pathogenicity.

Vascular movement of beet necrotic yellow vein virus in Beta macrocarpa is probably dependent on an RNA 3 sequence domain rather than a gene product.

“…RNA 3 has been implicated in virus proliferation in roots of Beta vulgaris and symptom expression (rhizomania) Koenig et al, 1991) whereas RNA 4 is important for Polymyxa betae-mediated transmission of the virus . RNA 5 is not present in all virus sources but it has been reported in some Japanese and European BNYVV isolates Kiguchi et al, 1996 ;Koenig et al, 1997). It can partially substitute for RNA 3 or interact synergistically with it when both are present .…”

Detection of Beet Necrotic Yellow Vein Virus by Double Stranded RNA Analysis

“…In some Asian, French and English isolates, 5th RNA, which is 1349 nucleotide long has been described (Saito et al, 1996;Koenig et al, 1997;Harju et al, 2002;Ward et al, 2007). RNA 1 and RNA 2 have "housekeeping" genes involved in replication, assembly and cell to cell movement, whereas RNA 3, RNA 4 and RNA 5 are associated with vector-mediated infection and disease development in sugar beet roots (Tamada, 2007).…”

Evidence for the presence of Beet necrotic yellow vein virus types A and B in Poland

“…Type A is present in most European countries, Iran, North America, China and Japan, whereas type B is detected frequently in France and Germany, and in Sweden, China and Japan occasionally (SAITO et al 1996;MIYANISHI et al 1999;LENNEFORS et al 2000;SOHI and MALEKI 2004). The isolates which contain five RNAs represent type P of BNYVV and so far have been found only in France (KOENIG et al 1999), the UK (HARJU et al 2002) and also in Kazakhstan . This type of BNYVV is known to be responsible for severe rhizomania symptoms even in resistant varieties (HEIJBROEK et al 1999).…”