Chemiotropism of Gigaspora rosea hyphae by Rhodotorula mucilaginosa exudates.

SCERVINO, J.M.; RODRÍGUEZ, M.A.; PONCE, M.A.; ERRA-BASSELLS, R.; GARCÍA ROMERA I.; OCAMPO, J.A.; GODEAS, A.M.

Granada, España

Conferencia; 5th Internacional Conference on Mycorrhiza; 2006

Estación Experimental del Zaidín. Consejo Superior de Investigaciones Científicas.

Chemotropism has been shown to be important in fungal contact with plant root. Exudates from roots and microorganisms play an important role in the attraction of arbuscular mycorrhizal (AM) fungi to the plant. Soil yeast benefits AM fungi mainly through its exudates. Exudates of Rhodotorula mucilaginosa increased the hyphal length of Gi. rosea spores. The highest hyphal growth of Gigaspora rosea was observed in presence of exudates of R. mucilaginosa from 24 to 48 h of yeast culture. Some of this beneficial substance can be attributed to the rhodoturolic acid (RA) produced by yeast. RA was detected only in culture of R. mucilaginosa after 24 h of culture. Higher attraction and growth of Gi. rosea hyphae in presence of RA exudates or exudates of R. mucilaginosa was observed. The hyphal length of Gi. rosea apores in presence of exudates from R. mucilaginosa was strongly correlated with the hyphal length of the spores in presence of exudates from RA. Our results indicate that RA can be involved in the chemotropism of AM fungi.