Identification of Coffee Genes Expressed During Systemic Acquired Resistance and Incompatible Interaction with Hemileia vastatrix

Coffee genes associated with systemic acquired resistance (SAR) and incompatible reaction against coffee leaf rust inoculation were identified by suppression subtractive hybridization. Analysis of 384 clones of each of the subtracted cDNA libraries identified genes involved in oxidative burst/apoptosis/hypersensitive response, synthesis of antimicrobial proteins, synthesis and transport of antimicrobial metabolites, signal perception and transduction, metabolism of lipids, regulated protein degradation and cell maintenance and development. Induction of distinct sets of genes in the two resistance responses was observed. A wide range of genes involved in defence responses described in other plant species was also found in coffee plants. Semi-quantitative and quantitative RT-PCR analysis of seven selected genes showed differences in their expression pro. le within 72 h after treatment. Full-length cDNA sequences of two beta-1,3-glucanases, one induced during SAR and the other in the incompatible reaction, were obtained by 5' and 3' RACE and the sequence data suggest different properties and cellular localization of the encoded proteins.