An interaction map of transcription factors controlling gynoecium development in Arabidopsis

Abstract

Flowers are composed of different organs, whose identity is defined at the molecular by the combinatorial activity of transcription factors (TFs). MADS-box TFs interact forming complexes that have been schematized in the quartet model. The gynoecium is the female reproductive part in the flower, crucial for plant reproduction, and fruit and seed production.Once carpel identity is established, a gynoecium containing many tissues arises. Several TFs have been identified as regulators of gynoecium development, and some of these TFs form complexes. However, broad knowledge about the interactions among these TFs is still scarce. In this work, we used a systems biology approach to understand the formation of a complex reproductive unit as the gynoecium by mapping binary interactions between wellcharacterized TFs. We analyzed over 3500 combinations and detected more than 200 protein-protein interactions (PPIs), resulting in a process specific interaction map.Topological analyses suggest hidden functions and novel roles for many TFs. Furthermore, a relationship between TFs involved in auxin and cytokinin signaling pathways and other TFs was observed. We analyzed the network by combining PPI data, expression and genetic data, allowing us to dissect it into several dynamic spatio-temporal sub-networks related to gynoecium development subprocesses.Arabidopsis has been studied for more than 20 years (Roeder and Yanofsky, 2006;Alvarez-Buylla et al., 2010). The accepted model for floral organ formation relies on the combinatorial action of mostly MADS-box proteins, resulting in the specification of the four whorls of the flower: sepals, petals, stamens and carpels (Coen and Meyerowitz, 1991).At the molecular level, MADS-box transcription factors (TFs) form complexes in order to regulate gene expression. For the female reproductive organs, the C-class and E-class

The genetic control of herkogamy

“…As herkogamy is determined by the positioning of anthers and stigmas in the flower, there is a need to understand the molecular control of growth and development of the gynoecium and stamens (filaments and anthers). The molecular regulation of growth and development of these floral structures have been extensively reviewed (Herrera-Ubaldo et al 2018Thomson and Wellmer 2019) so will not be covered in detail here. Key to the determination of the gynoecium and stamens are the floral homeotic B, C and E function genes.…”