RT Journal Article SR Electronic T1 Comparative transcriptomics reveals lineage specific evolution of cold response in Pooideae JF bioRxiv FD Cold Spring Harbor Laboratory SP 151431 DO 10.1101/151431 A1 Lars Grønvold A1 Marian Schubert A1 Simen R. Sandve A1 Siri Fjellheim A1 Torgeir R. Hvidsten YR 2017 UL http://biorxiv.org/content/early/2017/06/19/151431.abstract AB Background Understanding how complex traits evolve through adaptive changes in gene regulation remains a major challenge in evolutionary biology. Over the last ~50 million years, Earth has experienced climate cooling and ancestrally tropical plants have adapted to expanding temperate environments. The grass subfamily Pooideae dominates the grass flora of the temperate regions, but the role of cold-response gene regulation in the transitioning from tropical to temperate climate remains unexplored.Results To establish if molecular responses to cold are conserved throughout the phylogeny, we assembled the transcriptomes of five Pooideae species spanning early to later diverging lineages, and compared short- and long-term cold responsive genes using 8633 high confidence ortholog groups with resolved gene tree topologies. We found that a majority of cold responsive genes were specific to one or two lineages, an observation that we deem incompatible with a cold adapted Pooideae ancestor. However, all five species shared short-term cold response in a small set of general stress genes as well as the ability to down-regulate the photosynthetic machinery during cold temperatures.Conclusions Our observations indicate that the different Pooideae lineages have assembled cold response programs in parallel by taking advantage of a common potential for cold adaptation.