Although
B. 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. In addition, only ~21% of the
Brachypodium genome consists of repetitive elements, compared to 26% in rice and ~80% in wheat, further simplifying genetic mapping and sequencing. For early-flowering accessions it can take as little as 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.
B. distachyon 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. By now,
B. distachyon has established itself as an important tool for
comparative genomics. It is now emerging as a model for crop plant disease, facilitating the model-to-crop transfer of knowledge on disease resistance.
B. distachyon is also becoming a useful model system for studies of
evolutionary developmental biology, in particular to contrast molecular genetic mechanisms with dicotyledon model systems, notably
Arabidopsis thaliana. The finding of higher genetic diversity in eastern Iberian populations occurring in basic soils suggests that these populations can be better adapted than those occurring in western areas of the Iberian Peninsula where the soils are more acidic and accumulate toxic Al ions. ==Notes==