Development of ELISA for simultaneous detection of grapevine virus A (GVA) and grapevine virus B (GVB)
Goszczynski, D E
ARC Plant Protection Research Institute
Jooste, A E C
Rugose wood complex of grapevines comprising four graft transmissible diseases: Kober stem grooving (KSG), corky bark (CB), LN33 stem grooving (LNSG) and Rupestris stem pitting (RSP) are a serious problems for the grapevine industry worldwide. The diseases affect yield, rooting ability and graft take of grapevines. Infected grapevines may decline and die within a few years from planting. Eradication of these diseases from vineyards is very difficult as they frequently remain latent and the existing method of detection by biological indexing is time consuming and expensive.
There is growing evidence that viruses GVA and GVB from Vitivirus genus are involved in inducing symptoms of KSG and CB respectively. Recent studies of these viruses resulted in development of ELISA (based on serology) and PCR (based on nucleotide sequence data) techniques for their identification in grapevines. Although PCR is undoubtedly more sensitive then ELISA, disadvantages of this technique are lack of automation and recently discovered extensive variation of nucleotide sequence of GVB. The latter is especially dangerous as some strains of GVB (and perhaps GVA) may escape undetected by PCR, even if they occur in high concentration in grapevines. Such strains can then be propagated without being noticed.
An important advantage of ELISA for detection of GVA and GVB is that these viruses are serologically related and that strains of these viruses, which differ in reaction to polyclonal antisera, have not been detected yet. The viruses have identical cryptotope(s), which induce(s) a strong immunological response in virus-immunised rabbits. Results suggest that GVA and GVB are serologically related to other Vitiviruses. This may enable detection by a single test of other vitiviruses that are increasingly being detected in grapevines. GVA and GVB-specific antibodies will be purified from rabbit antisera by immunoaffinity, using columns with immobilised capsid proteins of viruses. Purified antibodies will be applied in ELISA.
Goszczynski, D E, Jooste, A E C and Kasdorf, G G F. 2002. Development of ELISA for simultaneous detection of grapevine virus A and grapevine virus B. Presentation at the Winetech Grapevine Virus Workshop. 6 May, Simondium, South Africa
Goszczynski, D E, Jooste, A E C and Kasdorf G, G F. 2003. ELISA for the detection of grapevine virus A and grapevine B: Production and some properties of goat antisera to GVA. Presentation at the Winetech Grapevine Virus Workshop. 5 May, ARC Infruitec-Nietvoorbij, Stellenbosch, South Africa