Olive leaf extract trigger defense physiological markers in Datura metel against tobacco mosaic virus

Abstract

Plants have been used as medicines since the time immemorial, among which Olea europaea products are widely available. Six essential oil extracts were tested for antiviral activities in Datura metel. The selected oils were Olive Leaf Extract (OLExt), Cinnamon, Clove, Black seed, Cedar, and Walnut oil. Datura metel was used as model host for TMV strain. The highest antiviral activity was observed in OLExt triggering physiological markers in Datura metel and showing reduced number and size of necrotic local lesion. Gas chromatography-mass spectroscopy (GC-MS) revealed the presence of three main compounds Iridoid glycosides, polysaccharides and phenolic acids in OLExt. Datura leaves were further analyzed for physiological markers. Among amino acids; alanine and serine found increased along with a significant rise in glutamine up to 7.16 mol/Kg DWT and methionine 0.128 Kg DWT in OLExt treated. There was an obvious increase in the lead, zinc, Chlorophyll A (from 1.75 to 1.93 mg/gm), total protein (from 2.8 to 3.12 mg/gm) and DNA (from 273.52 to 313.09 mg/gm). Fixing nucleus activity was assessed by comet assay in the value of tail moment unit from 18.870 in TMV to 12.314. These physiological markers were found to be parameters for virus host interaction in plant defense relay on Iridoids as an antiviral compound in OLExt.