Identification and expression analysis of Pal genes during elicitation of Olea europaea by Pseudomonas savastanoi

Abstract

Olea europaea L. is a cultivar of major importance in Portuguese economy. Among the diseases that affect Portuguese olive orchards’, olive-knot, caused by Pseudomonas savastanoi, is responsible for drastic reduction in olive oil production. It was observed that the impact of this disease in O. europaea Galega Vulgar was low when compared to what is observed in other Portuguese varieties. When elicitated with P. savastanoi, suspension cell cultures of O. europaea Galega Vulgar exhibit two bursts of superoxide ion production (100 and 300 minutes after the elicitation), characteristic of the Hypersensitive Response observed in incompatible plant-microbial interactions. Towards the identification of O. europaea genes involved in the defence mechanisms against P. savastanoi, we have constructed a cDNA library of elicitated cells. Screenings for the identification of genes encoding phenylpropanoid pathway enzymes (phenylalanine ammonia lyase- PAL- and chalcone synthase-CHS) were performed and expression analysis of the corresponding transcripts during the time course of elicitation is in progress.