The defence elicitor AsES causes a rapid and transient membrane depolarization, a triphasic oxidative burst and the accumulation of nitric oxide

MARTOS, GUSTAVO G.; TERÁN, MA. DEL MILAGRO; DÍAZ RICCI, JUAN C.

PLANT PHYSIOLOGY AND BIOCHEMISTRY

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Lugar: Paris; Año: 2015 vol. 97 p. 443 - 450

0981-9428

The newly characterizedelicitor AsES obtained from Acremoniumstrictum induces a strong defence response in strawberry plants and confersplants resistance against the fungal pathogen Colletotricum acutatum the casual agent of anthracnose disease. Previousstudies showed that AsES causes the accumulation of reactive oxygen species(ROS) that peaked 4 h post treatment (hpt), but due to the experimental approach used it was notclear whether the accumulation of ROS observed was intracellular or extracellularor took place as a single peak. By using a different experimental setup, a morecomplex early events associated to the activation of the innate immunity wereobserved. In this paper we report that strawberry plant cells treated with AsESexhibits a triphasic production of H2O2 and a rapidintracellular accumulation of NO. The first phase consists in a progressiveextracellular accumulation of H2O2 that startsimmediately after the treatment with AsES and is preceded by a rapid andtransient cell membrane depolarization. During this phase takes place also arapid intracellular accumulation of NO. Microscopic observations of mesophyllcells treated with AsES reveals that NO accumulates at the chloroplast. After thefirst extracellular H2O2 production phase, twointracellular H2O2 accumulation events occur, the first 2hpt, and the second 7 hpt. Cells treated with AsES also show a transientincrease of ion leakage, and a progressive alkalinization of the extracellularmedium.