Regulation of Late-Stage Flower Development by Downstream Genes of the Homeotic Protein AGAMOUS

The genes and pathways AG regulates in late-stage flower development are largely unknown. Several putative downstream genes of AG involved in anther dehiscence were identified, including DAD1, MYB26, OPR3, COI1, and RBR1, through a bioinformatics approach. A 35S::AG-GR inducible line was constructed for timed-induction expression analysis of anther dehiscence versus indehiscence, which revealed the likely direct induction of DAD1 by AG. Mutated AG binding sites of DAD1 and MYB26 were linked to the β-glucuronidase reporter gene; the plasmid constructs were transformed into plants for GUS staining to test in vivo site activity. Results support the hypothesis that AG is continually functional and controls late-stage flower development by regulation of downstream genes.