RT Journal Article SR Electronic T1 SUPERMAN prevents stamen formation and promotes stem cell termination in the fourth whorl of the Arabidopsis flower JF bioRxiv FD Cold Spring Harbor Laboratory SP 107722 DO 10.1101/107722 A1 Nathanaël Prunet A1 Weibing Yang A1 Pradeep Das A1 Elliot M. Meyerowitz A1 Thomas P. Jack YR 2017 UL http://biorxiv.org/content/early/2017/02/10/107722.abstract AB The molecular and genetic networks underlying the determination of floral organ identity are well studied, but much less is known about how the flower is partitioned into four developmentally distinct whorls. The SUPERMAN gene is required for proper specification of the boundary between stamens in whorl 3 and carpels in whorl 4, as superman mutants exhibit supernumerary stamens but usually lack carpels. However, it has remained unclear whether extra stamens in superman mutants originate from an organ identity change in whorl 4 or the overproliferation of whorl 3. Using live confocal imaging, we show that the extra stamens in superman mutants arise from cells in whorl 4, which change their fate from female to male, while floral stem cells proliferate longer, allowing for the production of additional stamens.