Graphical Abstract: The paper relates on the discovered bioactivity of the iridoid glycosides extract (IGE) from Linaria genistifolia (L.) Mill, namely its stimulating influence on the resistance of the winter wheat Odesschi 51 plant to the caused by the F. oxysporum and H. avenae pathogenic fungi root rot. 1H and 13C NMR characteristics of 5-O-allosylantirrinoside in Py-d5 are for the first time presented. Structures of two conformers of the IGE main component, 5-O-allosylantirrinoside in D2O and Py-d5 solutions are proposed, based on the experimental NMR evidence and molecular modeling studies.