Integrative genome-wide analysis reveals the role of WIP proteins in inhibition of growth and development

In cucurbits, CmWIP1 is a master gene controlling sex determination. To bring new insight in the function of CmWIP1, we investigated two Arabidopsis WIP transcription factors, AtWIP1/TT1 and AtWIP2/NTT. Using an inducible system we showed that WIPs are powerful inhibitor of growth and inducer of cell death. Using ChIP-seq and RNA-seq we revealed that most of the up-regulated genes bound by WIPs display a W-box motif, associated with stress signaling. In contrast, the down-regulated genes contain a GAGA motif, a known target of polycomb repressive complex. To validate the role of WIP proteins in inhibition of growth, we expressed AtWIP1/TT1 in carpel primordia and obtained male flowers, mimicking CmWIP1 function in melon. Using other promoters, we further demonstrated that WIPs can trigger growth arrest of both vegetative and reproductive organs. Our data supports an evolutionary conserved role of WIPs in recruiting gene networks controlling growth and adaptation to stress. Maria V Gomez Roldan, Farhaj Izhaq et al. study the role of WIP transcription factors in Arabidopsis thaliana. Using an inducible system, they generate ChIP-seq and RNA-seq data that reveal how WIP proteins repress development and growth. Through ectopic expression of WIP in Arabidopsis carpels, they obtain male flower, mimicking sex determination in melon.