GENE EXPRESSION RESPONSE OF ARABIDOPSIS THALIANA TO INOCULATION WITH PECTOBACTERIUM CAROTOVORUM subsp CAROTOVORUM
A.T. Djami-Tchatchou, T. Goszczynska, G.V. Subba Reddy, K. Ntushelo
Pectobacterium carotovorum subsp. carotovorum (Pcc) is a soft rot bacterial pathogen of a wide range of plant hosts. Under pathogen attack, plants respond locally as well as systemically by activating a broad spectrum of defense mechanisms. Systemic acquired resistance (SAR) as a response following inoculation of plants with Pcc is still poorly understood. Using the model plant Arabidopsis thaliana, we investigated the molecular basis of SAR following inoculation with Pcc. Five-week-old A. thaliana plants were inoculated with a lysogeny broth culture of Pcc, and leaves were sampled 24, 48 and 72 h after inoculation. The expression profiles of the plant defense genes: serine/threonine kinases, F-box, protease inhibitor, pathogenesis-related protein 1, phenylalanine ammonia lyase, Myb transcription factor, superoxide dismutase 1 and lipoxygenase were determined by real-time PCR to unveil the SAR mechanism after 24, 48 and 72 h after inoculation. The results revealed that Pcc inoculation triggered a genetic response in A. thaliana, which resulted in the differential expression of these selected plant defense genes. This suggests that these genes play an important role in the mechanism of response to Pcc.