An Efficient System for Ds Transposon Tagging in Brachypodium distachyon

Transposon tagging is a powerful tool that has been widely applied in several species for insertional mutagenesis in plants. Several efforts have aimed to create transfer-DNA (T-DNA) insertional mutant populations in Brachypodium distachyon , a monocot plant used as a model system to study temperate cereals, but there has been a lack of research aimed at using transposon strategies. Here, we describe the application of a maize ( Zea mays ) Dissociation ( Ds ) transposon tagging system in B distachyon The 35S :: AcTPase cassette and Ds element were constructed within the same T-DNA and transformed into B distachyon plants. The Ds element was readily transposed to other chromosomes or to the same chromosome under the function of Activator ( Ac ) transposase. Through homologous chromosome synapsis, recombination, and segregation, the Ds element separated from the Ac element. We selected stable Ds -only plants using G418 and GFP assays and analyzed 241 T 0 lines, some of which were highly efficient at producing Ds -only progeny. Through thermal asymmetric interlaced PCR, we isolated 710 independent Ds flanking sequences from Ds -only plants. Furthermore, we identified a large collection of mutants with visible developmental phenotypes via this transposon tagging system. The system is relatively simple and rapid in comparison to traditional T-DNA insertion strategies, because once efficiency lines are obtained they can be reused to generate more lines from nontransposed plants without the use of time-consuming tissue culture steps.