Differential Gene Expression in Bermudagrass Associated with Resistance to a Fungal Pathogen

Abstract

Bermudagrass, Cynodon dactylon (L.) Pers., is extensively used for turf and forage in many warm climatic regions of the world. Spring dead spot (SDS), caused by Ophiosphaerella herpotricha, is a serious fungal disease of turf bermudagrass in the southern USA. Suppression subtraction hybridization (SSH), sequencing of cDNA clones from forward and reverse normalized libraries, and cDNA microarrays were used to identify genes associated with resistance or susceptibility to this disease. During the fall and spring seasons, there were 80 and 66 singletons, respectively, that displayed more than a 2-fold differential expression between the resistant and susceptible cultivars. One hundred and seven responsive genes were grouped into six clusters according to their fall and spring expression profiles. The majority of differentially expressed genes had no homology to current accessions in NCBI GenBank. Of those clones with putative identities, the most interesting classes of genes differentially expressed between the resistant and susceptible cultivars were those involved in signaling pathways and the oxidative burst defense mechanism.