Fine-tuning of auxin homeostasis governs the transition from floral stem cell maintenance to gynoecium formation

• Published in: Nature communications Vol. 8; no. 1; pp. 1125 - 15
• Main Authors: Yamaguchi, Nobutoshi, Huang, Jiangbo, Xu, Yifeng, Tanoi, Keitaro, Ito, Toshiro
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24.10.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 631/449/1741/1576; 631/449/2653/2654; 631/449/2679/2684; Agricultural production; Arabidopsis; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - physiology; Binding Sites; Control; Crabs; Crop production; Crustaceans; Flowers - physiology; Gene Expression Profiling; Gene Expression Regulation, Plant; Gene silencing; Homeodomain Proteins - physiology; Homeostasis; Humanities and Social Sciences; Indoleacetic Acids - metabolism; Maxima; Meristem - physiology; multidisciplinary; Mutation; Phenotype; Phylogeny; Plant reproduction; Science; Science (multidisciplinary); Stem cells; Stem Cells - cytology; Stem Cells - physiology; Transcription Factors - physiology; Tuning
• DOI: 10.1038/s41467-017-01252-6
• ISSN: 2041-1723

To ensure successful plant reproduction and crop production, the spatial and temporal control of the termination of the floral meristem must be coordinated. In Arabidopsis , the timing of this termination is determined by AGAMOUS (AG). Following its termination, the floral meristem underdoes gynoecium formation. A direct target of AG, CRABS CLAW ( CRC ), is involved in both floral meristem determinacy and gynoecium development. However, how floral meristem termination is coordinated with gynoecium formation is not understood. Here, we identify a mechanistic link between floral meristem termination and gynoecium development through fine-tuning of auxin homeostasis by CRC. CRC controls auxin homeostasis in the medial region of the developing gynoecium to generate proper auxin maxima. This regulation partially occurs via direct transcriptional repression of TORNADO2 ( TRN2 ) by CRC. Plasma membrane-localized TRN2 modulates auxin homeostasis. We propose a model describing how regulation of auxin homeostasis mediates the transition from floral meristem termination to gynoecium development. In Arabidopsis , the timing of floral meristem termination is determined by AGAMOUS. Here, the authors show that the CRC transcription factor, itself a direct target of AGAMOUS, coordinates meristem termination with subsequent gynoecium formation partly by repressing TRN2 expression and regulating auxin homeostasis.