Influence of fungal diseases on phenolic compound composition and content in silver birch and Scots pine

Abstract

Currently, the role of phenolic compounds regarding tree resistance to fungal diseases is actively studied. The research goal was a comparative analysis of the influence of fungal diseases (stem rot and Lophodermium needle cast) on the composition and content of phenolic compounds in the leaves of silver birch (Betula pendula Roth.) and the needles of Scots pine (Pinus sylvestris L.). The composition and content of phenolic compounds were determined by using high-performance liquid chromatography. Partial coincidence in reactions was found in both tree species when affected by fungal pathogens accompanied by increasing content of some flavonoids and phenylpropanoids compared to control samples. Thus, in response to the action of fungal pathogens, birch and pine showed a positive reaction regarding some flavonoids (isorhamnetin, kaempferol and rutin), as well as phenylpropanoids (ferulic and 5-caffeoylquinic acids). At the same time, different intensities of responses to fungal pathogens in pine and birch were revealed due to the degree of plant damage as well as the characteristics of species relationships in the plant-pathogen system. A significant increase in isorhamnetin was found both in pine needles (by 93%) and birch leaves (by 56%) with damage by fungal diseases. Also noteworthy was the positive response of ferulic acid which had proven fungicidal properties to the action of fungal pathogens. The results obtained indicate the manifestation of the protective potential of some representatives of flavonoids and phenylpropanoids when affected by various fungal diseases of both silver birch and Scots pine. Overall, the findings of this study suggest the presence of some similar biochemical parameters of resistance to fungal diseases among different tree species.