Functional genomics of the Neotyphodium lolii / ryegrass symbiosis

Neotyphodium lolii is a fungal endophyte that lives entirely within the intercellular spaces of its grass host, perennial ryegrass (Lolium perenne, L.). Infection is symptomless and the endophyte relies on the host plant for dissemination via the seed. The association is mutually beneficial since the endophyte confers a number of biotic and abiotic advantages to the host. This paper presents an overview of the functional genomics approaches we are using at AgResearch to dissect the molecular basis of this symbiosis and will broadly describe the fields of genomics, transcriptomics, proteomics and metabolomics, as applied to this system. We have used isogenic ryegrass lines infected or uninfected with endophyte in combination with a suite of molecular biology tools, including Expressed Sequence Tags (ESTs), cDNA and Affymetrix GeneChip® microarray analysis, 2D-gel electrophoresis (to identify novel proteins associated with symbiosis), and metabolic profiling. By using a multidisciplinary approach we aim to identify genes which are important in both the establishment and maintenance of symbiosis, as well as elucidate how endophyte confers enhancements to its host. Keywords: Neotyphodium, Epichloë, symbiosis, functional genomics