Essential Oils and Latices as Novel Antiviral Agent Against Potato Leaf Roll Virus and Analysis of Their Phytochemical Constituents Responsible for Antiviral Activity

The present work was aimed to limit the practice of using pesticides in the managing program of the potato leaf roll disease on potato plants as the misuse of some pesticides had caused severe problems. The study was focused to find compounds nontoxic and safe for the biome. The antiviral activity of essential oils and latices tapped from different plants was investigated against potato leaf roll virus (PLRV). Essential oils from Eucalyptus citriodora leaves, Clove buds, and Fennel seeds were extracted. Latex of Aloe vera, Calotropis procera and Ficus elastic were collected. Essential oil and latex spray solutions were prepared at 5 and 10% concentration. All the sprayings were done at 7 days interval. Inhibition of viral replication was monitored by amplification of PLRV capsid protein gene and mRNA expression using RT-PCR technique. Results depicted inhibitory potential of all the tested essential oils and latices against PLRV infestation and also the effect was found concentration dependent. Our data showed that Aloe vera latex and clove essential oil caused maximum inhibition viral mRNA at 10% concentration. Qualitatively analyzed Tannin, Phlobactanins, Saponin, Flavonoids, Sterols and Terpens from essential oils and latices gave positive results in most of the oils and lesser content in plant latices. In the GC-MS analysis, high contents of some bioactive phytochemical compounds identified were Eugenol in Clove buds, Eucalyptol, D-Limonene and L-Limonene both in Eucalyptus leaves and Fennel seed oils and Fenchone in Fennel seeds. As this research work illustrates, there is innumerable potential of plants essential oils/latex waiting to be evaluated and exploited against genetically and functionally diverse plant viruses.