Evolution of dynamics of plant-mycorrhizal fungi-endophyte triadic relationships in heterotrophic plants

Myco-heterotrophic plants depend on fungi for their carbon resources. Studies on evolutionary changes of dynamics of plant-mycorrhizal fungi-endophyte triadic relationships in heterotrophic plant evolution have not been conducted so far. In this study, we focused on the evolutionary changes of the role of endophytes in the triadic relationships. Analyses on fungal flora in four phylogenetic groups of angiosperms revealed the reduction of species diversity during the evolution of heterotrophy. Interference competition was observed among some endophytes. Expressions of genes for MYB72 and NPR1 were not obviously different among plant species and, thus, the role change of endophytes seems to be small. Simplification of the triadic relationships was occurred during the evolution of myco-heterotrophy in angiosperms.