INVESTIGADORES
ROSSI franco Ruben
congresos y reuniones científicas
Título:
Toxic effect of phytotoxin Sirodesmin PL on Brassica napus (colza) seedlings.
Autor/es:
FRANCO ROSSI; CANDACE ELLIOTT; FERNANDO MATÍAS ROMERO; ANDRÉS GÁRRIZ; OSCAR ADOLFO RUIZ
Reunión:
Congreso; XXXII Reunión Argentina y XVI Congreso Latinoamericano de Fisiología Vegetal; 2018
Resumen:
Leptosphaeriamaculans is a hemibiotrophic fungus that affect a wide number of horticulturaland agronomic crops such as colza (Brassicanapus ssp oleifera). This funguscauses necrosis in leaves and cankers in the stem base and originates importanteconomic losses. The pathogen´s virulence depends largely on the production ofsecondary metabolites, including the phytotoxin Sirodesmin PL. This toxinbelongs to a wide group of compounds named epipolythiodioxopiperazine which arecharacterized by the presence of an internal disulphide bridge. It has beendemonstrated that L. maculans mutantsnon-producing sirodesmin are less virulent on stems of B. napus. Nevertheless, the toxicitymechanisms of this toxin is far from being understood. Here we demonstrate thatSirodesmin induces necrotic lesions in cotyledons at concentrations ranging 5-50µM, which is in concordance with cell death levels.The ability of Sirodesmin to cause cell death was abolished when thiscompound was maintained in the reduced state by the simultaneous presence ofNaBH4. Sirodesmin induces ROS accumulation asevidenced by DCFDA staining, as well as H2O2 andsuperoxide accumulation by DAB and NBT staining, respectively. Here wedemonstrate that this toxin require functional thiols for its toxicity and thatit modifies the redox status in plants.