Beschreibung:
<jats:title>Summary</jats:title><jats:p>Upon hormonal signaling, ovules develop as lateral organs from the placenta. Ovule numbers ultimately determine the number of seeds that develop, and thereby contribute to the final seed yield in crop plants. We demonstrate here that <jats:italic><jats:styled-content style="fixed-case">CUP</jats:styled-content>‐<jats:styled-content style="fixed-case">SHAPED COTYLEDON</jats:styled-content> 1</jats:italic> (<jats:italic><jats:styled-content style="fixed-case">CUC</jats:styled-content>1</jats:italic>), <jats:italic><jats:styled-content style="fixed-case">CUC</jats:styled-content>2</jats:italic> and <jats:italic><jats:styled-content style="fixed-case">AINTEGUMENTA</jats:styled-content></jats:italic> (<jats:italic><jats:styled-content style="fixed-case">ANT</jats:styled-content></jats:italic>) have additive effects on ovule primordia formation. We show that expression of the <jats:italic><jats:styled-content style="fixed-case">CUC</jats:styled-content>1</jats:italic> and <jats:italic><jats:styled-content style="fixed-case">CUC</jats:styled-content>2</jats:italic> genes is required to redundantly regulate expression of <jats:italic><jats:styled-content style="fixed-case">PINFORMED</jats:styled-content>1</jats:italic> (<jats:italic><jats:styled-content style="fixed-case">PIN</jats:styled-content>1</jats:italic>), which in turn is required for ovule primordia formation. Furthermore, our results suggest that the auxin response factor <jats:italic><jats:styled-content style="fixed-case">MONOPTEROS</jats:styled-content></jats:italic> (<jats:italic><jats:styled-content style="fixed-case">MP</jats:styled-content></jats:italic>/<jats:italic><jats:styled-content style="fixed-case">ARF</jats:styled-content>5</jats:italic>) may directly bind <jats:italic><jats:styled-content style="fixed-case">ANT</jats:styled-content></jats:italic>,<jats:italic> <jats:styled-content style="fixed-case">CUC</jats:styled-content>1</jats:italic> and <jats:italic><jats:styled-content style="fixed-case">CUC</jats:styled-content>2</jats:italic> and promote their transcription. Based on our findings, we propose an integrative model to describe the molecular mechanisms of the early stages of ovule development.</jats:p>