Background: Little is known about the potential of Brachypodium distachyon as a model for low temperature stress
responses in Pooideae. The ice recrystallization inhibition protein (IRIP) genes, fructosyltransferase (FST) genes, and
many C-repeat binding factor (CBF) genes are Pooideae specific and important in low temperature responses. Here
we used comparative analyses to study conservation and evolution of these gene families in B. distachyon to better
understand its potential as a model species for agriculturally important temperate grasses.
Results: Brachypodium distachyon contains cold responsive IRIP genes which have evolved through Brachypodium
specific gene family expansions. A large cold responsive CBF3 subfamily was identified in B. distachyon, while CBF4
homologs are absent from the genome. No B. distachyon FST gene homologs encode typical core Pooideae
FST-motifs and low temperature induced fructan accumulation was dramatically different in B. distachyon compared
to core Pooideae species.
Conclusions: We conclude that B. distachyon can serve as an interesting model for specific molecular mechanisms
involved in low temperature responses in core Pooideae species. However, the evolutionary history of key genes
involved in low temperature responses has been different in Brachypodium and core Pooideae species. These
differences limit the use of B. distachyon as a model for holistic studies relevant for agricultural core Pooideae species.Keywords: Gene family evolution,
Cold climate adaptation,
Fructosyltransferase,
Brachypodium distachyon,
Ice recrystallization inhibition protein,
C-repeat binding factor,
Gene expressio
