Flower development: from morphodynamics to morphomechanics

Abstract

The shoot apical meristem (SAM) is a small population of stem cells that continuously generates organs and tissues. We will discuss here flower formation at the SAM, which involves a complex network of regulatory genes and signalling molecules. A major downstream target of this network is the extracellular matrix or cell wall, which is a local determinant for both growth rates and growth directions. We will discuss here a number of recent studies aimed at analysing the link between cell wall structure and molecular regulation. This has involved multidisciplinary approaches including quantitative imaging, molecular genetics, computational biology and biophysics. A scenario emerges where molecular networks impact on both cell wall anisotropy and synthesis, thus causing the rapid outgrowth of organs at specific locations. More specifically, this involves two interdependent processes: the activation of wall remodelling enzymes and changes in microtubule dynamics.This article is part of the themed issue ‘Systems morphodynamics: understanding the development of tissue hardware’.

A multiscale analysis of early flower development in Arabidopsis provides an integrated view of molecular regulation and growth control

“…shape changes during development (Coen et al, 2004;Whitewoods and Coen, 2017). This should then provide a solid basis for more mechanistic studies, involving also the regulation of biochemical interactions and biophysical aspects (Abad et al, 2017;Diaz de la Loza and Thompson, 2017;Pasakarnis et al, 2016;Thompson, 1917;Zhu and Roeder, 2020).…”

The Arabidopsis SAC9 Enzyme is enriched in a cortical population of early endosomes and restricts PI(4,5)P2 at the Plasma Membrane

“…In animal cells, a phosphoinositide conversion cascade has been described through the successive action of phosphoinositide kinases and phosphatases. This cascade starts with PI(4,5)P 2 at the plasma membrane and ends-up with PI3P in the membrane of early endosomes (Noack and Jaillais 2017; Schmid and Mettlen 2013; Abad et al 2017; Posor et al 2015; Posor et al 2013; Shin et al 2005). Briefly, PI(4,5)P 2 is dephosphorylated at the plasma membrane or during the endocytic process by 5-phosphatase enzymes such as OCRL and synaptojanin (De Matteis et al 2017)(Cauvin et al 2016; Nandez et al 2014; Ben El Kadhi et al 2011; Posor et al 2013).…”

Drawing a Line: Grasses and Boundaries

“…These features contrast with the high cell division and cell expansion rates, low cell wall stiffness, and perpendicular oriented microtubules in the primordium tissue. The difference between the tissue properties of boundaries and the primordium generates conflict within the tissue, which allows the physical bulging of the primordium from the surface of the meristem [18,19,20]. The distribution of differentially growing regions can then generate distinct shapes [21].…”