Effect of Pine Callus Elicitation by the Fusarium Strains of Various Pathogenicity on the Content of Phenolic Compounds

Pine (Pinus sylvestris L.) callus culture was treated with the mycelium extracts from six Fusarium strains. Previously, pine seedlings were infected with a spore suspension in order to test the pathogenicity of the used strains. Callus culture infection resulted in a decrease in the free proanthocyanidin (PA) and an increase in bound PA content. After treating the calli with all strains except F. oxysporum var. orthoceras, the lignin content became lower than the control one. The most considerable changes involved the p-hydroxybenzoic acid (HBA) content, and its greatest change was observed after treating the calli with F. nivale, when the HBA concentration (1229 g/g dry wt) exceeded fourfold the control one. There was a positive correlation (R = 0.81) between the HBA content in the callus culture cells treated with a fungal extract and the virulence of Fusarium strains. At the same time, there was an inverse correlation (R = –0.80) between the lignin content in a callus culture and the fungal virulence; the latter did not affect the contents of both free and bound PA.