Suillus variegates improves early development of Scots pine seedlings

Polyamines are nitrogenous, growth regulator like compounds, which are present in all living organisms. In plants, polyamines affect, for example, cell division, differentiation and stress tolerance. The project is coordinated by Metla and funded by the Academy of Finland.

In laboratory experiments the roots of young seedlings of Scots pine were inoculated with the mycelium of S. variegatus and the development of the mycorrhizal interaction and changes in polyamine concentrations were monitored for five weeks. In the presence of the mycorrhizal fungus, the gene essential for the formation of polyamines was activated in wide areas of the developing root vascular tissue of the young Scots pine seedlings.

The results show that the fungus induces the synthesis of plant polyamines and that polyamines play an important role in the formation of the symbiosis between S. variegatus and Scots pine seedlings. Mycorrhizal fungi are able to produce different amounts of polyamines. The results encourage researchers to continue studying the interaction between the mycorrhizal symbiosis and polyamines.

The results of this study could contribute to future research aiming to, for example, the production of certain symbiotic mycorrhizal fungi vital for trees. A good symbiotic fungus enhances early development of young seedlings and may also protect from pathogens. Hence, inoculation with mycorrhizal fungi could enhance the growth of young seedlings, especially in problematic regeneration areas such as drained peatlands.