Brachypodium Distachyon - Model Organism

Model Organism

Although Brachypodium distachyon has little or no direct agricultural significance, it has several advantages as an experimental model organism for understanding the genetic, cellular and molecular biology of temperate grasses. The relatively small size of its genome makes it useful for genetic mapping and sequencing. At about 272 million base pairs and with five chromosomes, it has a small genome for a grass species. Brachypodium distachyon's small size and rapid life cycle are also advantages. For early-flowering accessions it takes about three weeks from germination to flower (under an appropriate inductive photoperiod). The small size of some accessions makes it convenient for cultivation in a small space. As a weed it grows easily without specialized growing conditions.

Brachypodium is emerging as a powerful model with a growing research community. The International Brachypodium Initiative (IBI) held its first genomics meeting and workshop at the PAG XIV conference in San Diego, California in January 2006. The goal of the IBI is to promote the development of B. distachyon as a model system and will develop and distribute genomic, genetic, and bioinformatics resources such as reference genotypes, BAC libraries, genetic markers, mapping populations, and a genome sequence database. Recently, efficient Agrobacterium-mediated transformation systems have been developed for a range of Brachypodium genotypes enabling the development of T-DNA mutant collections. The characterization and distribution of T-DNA insertion lines has been initiated to facilitate the understanding of gene function in grasses. Besides researchers already working with B. distachyon, other plant research communities will benefit from the availability of these resources. Researchers also are hopeful that Brachypodium may one day unlock the mystery behind biofuels. Using Brachypodium as a model organism, scientists at the Agricultural Research Service have developed a successful method to insert genes into the plant and hope to use this method to break down the plant’s cell wall in order to produce the necessary ethanol from the cellulosic biomass.