Mutator transposon activity reprograms the transcriptomes and proteomes of developing maize anthers.

Despite the high conservation of anther gene expression patterns across maize lines, Mu transposition programmed by transcriptionally active MuDR results in a 25% change in the transcriptome, monitored over 90 h of immature anther development, without altering the morphology, anatomy or pace of development. Most transcriptome changes are stage specific: cases of suppression of normal transcripts and ectopic activation are equally represented. Protein abundance changes were validated for numerous metabolic enzymes, and highlight the increased carbon and reactive oxygen management in Mutator anthers. Active Mutator lines appear to experience chronic stress, on a par with abiotic treatments that stimulate early flowering. Despite the diversity of acclimation responses, anther development progresses normally, in contrast to male-sterile mutants that disrupt anther cell fate or function completely, and cause fewer transcriptome changes. The early flowering phenotype ultimately confers an advantage in Mu element transmission.