Parasitic plant infection is partially controlled through symbiotic pathways

P>Legumes are unique in interacting with Rhizobium, arbuscular mycorrhizal (AM) fungi, and parasitic plants. To dissect common parts of these three plant-organism interactions, infection by Orobanche crenata was studied in mutants with altered symbiotic phenotypes of Medicago truncatula and Pisum sativum. Orobanche crenata inoculation of mutant lines carrying defective mutation in the genes dmi2/sym19 and dmi3 resulted in an increase in O. crenata establishment. Similarly, inoculation of mutants carrying mutation in the gene sunn/sym29 that controls the autoregulation mechanism of the symbiosis, also lead to a significant increase in haustoria formation. Altogether, our results suggest that parasitic plant infection is partly controlled by both the conserved symbiotic pathway that mediates symbiont recognition and establishment and the autoregulation mechanism that regulates the extent of colonisation by Rhizobium and AM fungi.