Elicitor-stimulated ion fluxes and O2− from the oxidative burst are essential components in triggering defense gene activation and phytoalexin synthesis in parsley

AUTOR(ES)

Jabs, Thorsten

FONTE

The National Academy of Sciences of the USA

RESUMO

Fungal elicitor stimulates a multicomponent defense response in cultured parsley cells (Petroselinum crispum). Early elements of this receptor-mediated response are ion fluxes across the plasma membrane and the production of reactive oxygen species (ROS), sequentially followed by defense gene activation and phytoalexin accumulation. Omission of Ca2+ from the culture medium or inhibition of elicitor-stimulated ion fluxes by ion channel blockers prevented the latter three reactions, all of which were triggered in the absence of elicitor by amphotericin B-induced ion fluxes. Inhibition of elicitor-stimulated ROS production using diphenylene iodonium blocked defense gene activation and phytoalexin accumulation. O2− but not H2O2 stimulated phytoalexin accumulation, without inducing proton fluxes. These results demonstrate a causal relationship between early and late reactions of parsley cells to the elicitor and indicate a sequence of signaling events from receptor-mediated activation of ion channels via ROS production and defense gene activation to phytoalexin synthesis. Within this sequence, O2− rather than H2O2 appears to trigger the subsequent reactions.

Documentos Relacionados

• Plasma Membrane Redox Enzyme Is Involved in the Synthesis of O2- and H2O2 by Phytophthora Elicitor-Stimulated Rose Cells.
• Oligopeptide elicitor-mediated defense gene activation in cultured parsley cells.
• Dark-Stimulated Calcium Ion Fluxes in the Chloroplast Stroma and Cytosol
• Role of Jasmonates in the Elicitor- and Wound-Inducible Expression of Defense Genes in Parsley and Transgenic Tobacco.
• Potentiation of the Oxidative Burst and Isoflavonoid Phytoalexin Accumulation by Serine Protease Inhibitors1