ROS ACTIVATED IN STRAWBERRY PLANTS BY SMS IS SUPRESSED BY SUPERNATANT OF Colletotrichum acutatum

TOMAS GRAU RODRIGO; REQUENA SERRA FERNANDO; GUERRERO MOLINA FERNANDA; PERATO SILVIA MARISA; MARTINEZ ZAMORA GUSTAVO; DIAZ RICCI JUAN CARLOS

ROSARIO

Congreso; SOCIEDAD ARGENTINA DE INVESTIGACION EN BIOQUIMICA Y BIOLOGIA MOLECULAR (SAIB); 2014

The generation of Reactive Oxygen Species (ROS) is one of the early defense responses activated in plants by biotic and abiotic stresses. Previously, we observed ROS production and up-regulation of catalase and pathogenesis related protein 1 (FaCAT and FaPR1) genes in strawberry leaves subjected to Solf Mechanical Stimulation (SMS, softly pressing the leaves with the fingertips). The aim of the work was to evaluate the effect of treatment with the supernatant of the virulent isolate M11 of Colletotrichum acutatum (SN-M11) on the biochemical and molecular responsesof SMS in strawberry. Four treatments were applied to axenic in vitro strawberry plants by triplicate: 1) SN-M11, 2) SMS, 3) SN-M11 and 4 hours later SMS and 4) H2O. Leaves where then removed for histochemical staining (NBT and DAB) and RNA extraction. The expression of FaCAT and FaPR1 genes were analyzed by qPCR. Results showed that leaves treated with the SN-M11 exhibited lesser H2O2 and O2- production that SMS treated plants, showing also a down-regulation of FaCAT transcripts. Nevertheless, up-regulation of FaPR1 was observed in treatments 2)and 3) as compared to 1) and 4). These results suggest that SN-M11 suppresses the production of ROS but not the defensive response activated by SMS.