10th INTERNATIONAL VERTICILLIUM SYMPOSIUM 16-20 ...

PRODUCTION AND SCAVENGING OF ROS DURING POTATO-VERTICILLIUM DAHLIAE INTERACTIONS: STRBOH GENESEXPRESSION AND ROLE OF SECONDARY METABOLITESM. BADAWI, L. R. ADAM, A. F. EL-BEBANY, A. EL HADRAMI* AND F.DAAYF*University of Manitoba, Department of Plant Science, 222 Agriculture Building Winnipeg, MB, R3T2N2 Canada.* E-mails: elhadrami@cc.umanitoba.ca; daayff@cc.umanitoba.caProduction of reactive oxygen species (ROS) is one of the earliest eventsfollowing pathogen recognition in plants. The respiratory burst oxidase (Rboh)encodes the key enzymatic subunit of plant NADPH oxidases. Rboh represents theplant genes family homolog of the catalytic subunit of phagocyte NADPH oxidase(gp91 phox ). Both are involved in superoxide formation. Our investigation intends tobetter understand the role of rboh genes in potato defense responses against V.dahliae. We followed the transcriptional regulation of Strboh A, B, C, D and F inpotato roots and leaves from a susceptible and moderately resistant cultivars, afterinoculation with either a highly or a weakly aggressive isolate of V. dahliae. GenesStrboh A, B, C and D were differentially up-regulated and their expression patternswere different between the leaves and the roots. In parallel, secondary metabolitesaccumulation accompanying these early events was analyzed using HPLC-DAD and–FLD. Spatiotemporal integration of both types of stress responses is being analyzedand correlated to the chronology of the interaction events.73