A novel alpha (a)-1,3-glucan induces protection against Rhizoctonia solani AG-3.

WOLSKI, E.; MALDONADO, S.; DALEO, G. R.; ADRIANA BALBINA ANDREU

Quebec, Canada

Congreso; American Phytopathological Annual Meeting; 2006

American Phytopathological Society

All glucan elicitors from fungal cell walls, which trigger plant defense responses, have been described as ß-glucans. In a previous work we have isolated and characterized an a-1,3-glucan which induced pathogenesis-related proteins in potato sprouts. In this work, we showed that, in addition to eliciting a wide array of defense reactions, the a-1,3-glucan induces protection against the disease caused by the pathogen Rhizoctonia solani AG-3. Protection assays showed that the pretreatment of potato sprouts with the a-1,3-glucan results in 40% of protection. Histological studies showed an increase in cell wall deposition of callose and lignin, which contribute to disease resistance by reinforcing the plant cell wall. Ultrastructural analysis, by electron microscopy, of the elicited tissue showed changes on the cytoplasm and the accumulation of electron-dense bodies in vacuoles. On the other hand, preliminary results showed that the treatment with the glucan confers protection against the dry rot disease agent, Fusarium solani f. sp.eumartii, indicating that this compound could be effective against others pathogens. The degree of protection may conceivably be increased by improving the penetration of the elicitor, formulation and combination with other control methods.