Brachypodium as a Model System for Investigating Cellular Function of Pollen Allergens
Brachypodium distachyon has been recognized as an ideal model plant for grass functional genomics as it is phylogenetically related to important food crops and turf grasses. The availability of the genome sequence and protocols for the plant transformations allows investigations of the functional role of genes in this plant. It is a self-pollinated plant reaching up to 15–20 cm height at maturity and has a short life cycle (8-12 weeks). Among grasses, it exhibits one of the smallest genomes (272 Mbp; 26,000 genes excluding isoforms). Close evolutionary relationship of Brachypodium with allergenic grasses such as ryegrass and bermuda grass is an ideal model organism for investigating origin and function of grass pollen allergens. We are currently employing next generation sequencing for transcriptome-based analysis of Rye grass, Bermuda grass and Brachypodium pollen gene expression repertoire to help us to identify key allergen-encoding genes and understand the conservation pattern of allergens in the grasses. We are also investigating in vivo function of pollen allergen genes via genetic transformation of Brachypodium with RNAi constructs targeting group 1 and 5 allergen genes.