Effect of chemical and heat therapy on virus concentrations in in vitro potato plantlets

Abstract

Effect of chemical and heat therapy on virus concentrations in in vitro potato plantlets. Can. J. Bot. 68: 1515-1521.Potato (Solanurn tuberosum) plantlets were established in vitro to evaluate the effectiveness of chemicals and heat therapy for antiviral activity. Ribavirin was shown to be the most active chemical. Further studies were performed in which plantlets established from nodal cuttings were exposed to an alternating 4-h cycle of 35-31°C and ribavirin (20 mg/L) therapy for 4 weeks, and then tested quantitatively for virus titer by the enzyme-linked immunosorbent assay. Plantlets were further propagated via nodal cuttings at room temperature without exposure to ribavirin. Virus assays were performed and virus-free plantlets were grown out as mature plants for a final virus assay. Ribavirin alone or in combination with heat therapy was effective in reducing potato virus M, S, and X titers (between 10-and 60-fold). Virus-free plants were obtained from both treatments. For potato viruses Y and leafroll, about a fourfold reduction in titer was observed after the ribavirin-heat treatments. When multiple viruses were present, quantitative (10-to 20-fold) reductions in potato viruses M, S, X, and leafroll were observed and resulted in plants free of potato viruses M, S, and X. This protocol enables the investigator to quantitatively monitor the impact of a single variable on the virus-host interaction. We have alsoTeen able to demonstrate that virus elimination can be obtained without a requisite meristem-tip excision step. GRIFFITHS, H. M., SLACK, S. A . , et DODDS, J. H. 1990. Effect of chemical and heat therapy on virus concentrations in in vitro potato plantlets. Can. J. Bot. 68 : 1515-1521. Des plantules de Pomme de terre (Solanurn tuberosurn) furent Ctablies in vitro afin d'Cvaluer l'efficacitt de certains produits chimiques et de la thermothtrapie sur 1'activitC antivirale. La ribavirine a Ct C la substance chimique la plus active. D'autres Ctudes furent rCalisCes oh des plantules provenant de sections nodales furent exposCes i une alternance de cycles thkrapeutiques de 35-31°C d'une durCe de 4 h en presence de ribavirine (20 mg/L), pendant 4 semaines, et puis testtes quantitativement pour la concentration en virus par l'essai immunosorbant d'enzymes liCes. Les plantules furent de nouveau propagees via des sections nodales i temperature de la pikce et en l'absence de ribavirine. Des essais viraux furent rCalists et des plantules sans virus furent cultivtes jusqu'au stade de plantes matures en vue d'un essai viral final. La ribavirine seule ou en combinaison avec la themotherapie a rCduit la concentration des virus de la pomme de terre M, S et X de 10 i 60 fois. Des plantes sans virus furent obtenues des deux traitements. Quant au virus Y et i celui de I'enroulement, l'on a observC une rkduction quadruple de la concentration pour les traitements ribavirine-chaleur. Lorsque plusieurs virus Ctaient prksents, des reductions quantitatives des virus M, S, X et de l'enroulement (rtductions de 10 i 20 fois) furen...

Cryotherapy of Potato Shoot Tips for Efficient Elimination of Potato Leafroll Virus (PLRV) and Potato Virus Y (PVY)

“…Conventional methods such as meristem culture, thermotherapy and thermotherapy followed by meristem culture have been successfully applied to obtain virus-free plants of potato (Lozoya-Saldaña and Dawson 1982;Faccioli and Rubies-Autonell 1982;Lozoya-Saldaña and Merlin-Lara 1984;Faccioli et al 1988;Griffiths and Slack 1990;Sanchez et al 1991;Faccioli and Colombarini 1996;Slack and Singh 1998;Faccioli 2001). Results of the present study confirm previous reports that PLRV and PVY could be eradicated by meristem culture, thermotherapy and thermotherapy followed by meristem culture.…”

“…When thermotherapy and thermotherapy followed by meristem culture are employed, infected stock plants have to be heat-treated by growing at high temperatures for several weeks (Faccioli and Rubies-Autonell 1982;Lozoya-Saldaña and Dawson 1982;LozoyaSaldaña and Merlin-Lara 1984;Griffiths and Slack 1990;Faccioli and Colombarini 1996). For some heat-stable potato virus strains Stace-Smith 1970, 1971), thermotherapy alone might not be sufficient to eradicate them.…”

In vitroelimination of onion yellow dwarf and shallot latent viruses in shallots (Allium cepavar.ascalonicumL.)

“…The successful combination of these two therapies, heat and chemical, has been reported by Griffiths et al (1990). They devised a system whereby potato plantlets grown in vitro were exposed to heat and chemical therapy that resulted in successful virus elimination.…”

Plant Cell, Tissue and Organ Culture

“…Plantlets in tissue culture provide the base for rapid multiplication of potato seedstocks (Bryan 1988), and for chemical and heat therapy procedures that improve the efficiency of virus elimination (Griffiths et al 1990;Sanchez et al 1991). Excision of the meristem and regeneration of plantlets on hormoneamended media have permitted the propagation of plants free from systemically invasive viruses and from other disease-causing pathogens.…”