Expression profiling of putative Eucalyptus grandis defence marker genes in response to treatment with methyl jasmonate and salicylic acid

Background Eucalyptus species and their hybrids encompass approximately 40% of forestry plantation area in South Africa and contribute significantly to the paper pulp industry due to their favourable wood fibre properties. Eucalypt plantation trees are affected by numerous pathogens during their lifetime, some of which can cause severe losses such as Phytophtora spp and Chrysoporthe spp. Plant defence mechanisms against pathogens is currently better understood in the model plant Arabidopsis thaliana where it has been shown that the salicylic acid (SA) and jasmonic acid (JA) signalling pathways enhance resistance against biotrophic and necrotrophic pathogens, respectively [1] . This process involves the up-regulation of specific defence genes which are considered to be marker (diagnostic) genes for the two signalling pathways [2,3].