466 / 2019-02-27 13:29:19

ANGUSTIFOLIA3/AtGIF1, as a key element in shoot morphogenesis

AN3,leaf,Cell domain，Gene regulatory network，Shoot apical meristem，Axillary meristem，Leaf,GRF,meritem

Growth and Development > Growth and Development

ANGUSTIFOLIA3 (AN3)/AtGIF1 was originally identified as the gene responsible for the narrow leaf phenotype of Arabidopsis an3 mutant. AN3 was firstly revealed to function as a co-activator by interacting with GRF transcription factors, the positive regulators of cell proliferation in leaf primordia. Afterward, AN3 has been revealed to cooperatively play a key role with HANABATARANU in defining the cotyledonary region during embryogenesis (Kanei et al. 2012 Development); identified as the mobile factor that synchronizes cell division between mesophyll and epidermis (Kawade et al. 2013 Curr. Biol), and also a component that determines leaf meristematic region by intercellular diffusion along the longitudinal axis of leaf primordia (Kawade et al. 2017 Biophys. J). Interestingly, studies on AN3 orthologs in rice and maize confirmed its previously recognized roles and further identified other species-unique roles of AN3. For example, while AN3 mRNA of Arabidopsis expresses specifically in mesophyll cells in leaf primordia, that of rice expresses only in the epidermis (Shimano et al. 2018 Development).
Recently, our metabolomics analysis strongly indicated that AN3 is also involved in metabolism control. To get clues to understand the ancestral role of AN3 in morphogenesis of land plants, we started analyses of loss-of-function mutants of Physcomitrella AN3 (PpAN3). Based on the data, we will discuss the fundamental roles of AN3 in plant morphogenesis.