Effect of pine pinus silvestris root extractives on growth regulators and iaa oxidase activity in pure cultures of mycorrhizal fungi
Acta Physiologiae Plantarum 2(2): 133-144
Cultures of mycorrhizal fungi [Suillus bovinus, S. luteus, Rhizopogon luteolus, Amanita muscaria and Cenococcum graniforme] were grown on sterile synthetic medium supplemented with powdered roots from pine seedlings which were grown either under full or reduced light conditions. In roots of seedlings from reduced light conditions a drop in total phenolics and leucoanthocyanins was observed. Fungal cultures supplemented with root-powder from full light showed growth increase and an enhanced level of auxin and cytokinin synthesis. The activity of IAA-oxidase preparations was inhibited by aqueous root extracts, exudates from roots, and by filtrates from fungal cultures supplemented with the root-powder, derived from pine seedlings which were grown in full light. There is some factor in pine roots, probably polyphenols, the quantity of which is dependent on the light conditions under which the seedling was grown. This factor favors the growth of mycelium and the production of auxin and cytokinin in cultures of mycorrhizal fungi. There is evidence that both hormones play an important role in the process of establishing the symbiotic relationship.