Correlated trophic and bioactive activities in the parasite-host relationship – Phelipanche purpurea vs. Achillea arabica case study

Abstract

Plant response to abiotic and biotic stresses was presented in a peculiar and relatively unknown symbiotic system, which is the relationship between the soil, obligate parasite and its host used as a medicinal and aromatic herb. This study has determined the bioaccumulation and translocation of micro/macro-nutrients and toxic substances from the soil into and within defined plant organs of a parasite (Phelipanche purpurea) and its host (Achillea arabica). There were 55 polyphenols identified; 38 compounds (average content of 2638.93 mg/100 g d.w.) - host plant and 17 compounds (average content of 3049.35 mg/100 g d.w.) - parasite plant. Some P. purpurea parasite polyphenols had been identified in its fractions for the first time. The profile of host polyphenols differed qualitatively and quantitatively from that of the P. purpurea parasite, only polyumoside and 2'-O-acetylpolyumoside were qualitatively identical in both. The phenylethanoid glycosides (PhGs’) were the most important compounds in the parasite and accounted for an average of 99% of all polyphenols (average content of 2996.85 mg/100 g d.w.) whilst flavonols and flavones (F&F) were most important in the host and accounted for an average of 55% of all polyphenols (average content of 1382.37 mg/100 g d.w.). The roots of the host, presented the highest antioxidant activity (178.4 umol Trolox (T)/g d.w. for ABTS assay, 318.9 umol T/g d.w. for DPPH, and 51.3 umol T/g d.w. for FRAP), whilst flowers of parasite noted the higher inhibition activity of α-glucosidase, but stems with tuber – higher inhibition activity of α-amylase. In turn, the host, presented the highest amount of Zn and Ca (average 28.0 and 5.3 mg/1000 g), whilst the parasite noted the higher amount of K (average 16.4 mg/1000 g). Holoparasites of A. arabica are promising sources for generating novel products with advantageous effects and high prospects to develop in the food and/or pharmacy industry.