Establishing a Genome-Wide Sequence-Indexed Collection of Brachypodium Mutants

Brachypodium distachyon has emerged as a powerful model system to address fundamental questions in grass biology. Gaining insights into the function of more than 25,000 genes identified from its sequenced genome will further expand its utility for basic research. To this end, we are establishing a sequence-indexed library of mutations generated by chemical and radiation mutagenesis. Three Brachypodium mutagenized populations were produced using ethyl methanesulfonate (EMS), sodium azide (NaN3) and fast-neutron radiation (FNR). With the decreasing cost of DNA sequencing, we utilized whole genome sequencing (WGS) to identify the genomic variations introduced by these mutagens. Results from the pilot sequencing of 91 lines resulted in about 45,000 novel mutations identified.  We will discuss the nature of the introduced mutations from chemical and radiation mutagenesis and the lessons we have learned from the process of identifying these new genomic variations.