Resistance to the herbicide 2,4-D in Sisymbrium orientale conferred by a deletion mutation in the degron tail of IAA2

Resistance to the phenoxy synthetic auxin herbicide 2,4-D is conferred by a deletion mutation in the degron tail of IAA2. An RNA-Seq experiment was used to assemble a reference transcriptome for the weed species Sisymbrium orientale, to quantify gene expression, and to identify sequence variants in the alignments. A 27 bp deletion was identified in the IAA2 gene. Forward genetics supported the role of this deletion mutation in resistance. The IAA2 deletion allele was transformed into Arabidopsis thaliana to confirm that it conferred 2,4-D resistance. Young leaves were sampled for RNA extraction and preparation of Illumina Hi-Seq libraries. Samples were collected only from untreated plants.