Biology subjects

Routier-Kierzkowska, A.-L.

Publications and source records attributed to Routier-Kierzkowska, A.-L..

7 recordsLinked to original sources

bioRxiv2026

Robust Organ Shape During Growth Requires Local Morphogen Signaling and Global Curvature Feedback

Precise organ shape during development requires feedback between organ-scale geometry and cell-level growth dynamics. Here, we use the apical hook of dicotyledonous plants as a model to study this multiscale control. This protective structure forms a [~]180{degrees} bend that is stably maintained despite rapid elongation. Combining quantitative growth mapping, multiscale modeling, and hormone analysis, we identify the cellular dynamics underlying hook maintenance. Contrary to the prevailing model, hook stability does not arise from sustained inner-outer growth asymmetry. Instead, stable curvature emerges from a biphasic, self-similar growth pattern that remains spatially fixed despite continuous cell flux. Auxin-driven growth asymmetry induces bending but is spatially restricted and insufficient to maintain shape. By contrast, a graded, auxin-independent autotropic response provides curvature-dependent growth regulation that counteracts bending and stabilizes shape against perturbations. Together, these findings establish a general principle in which local morphogen-driven bending and global geometry-dependent feedback jointly maintain robust organ shape during growth. HighlightsO_LISelf-similar growth maintains apical hook curvature despite continuous cell flux C_LIO_LICurvature stability emerges from coordinated axial and differential growth C_LIO_LIAuxin asymmetry is spatially restricted and insufficient for shape maintenance C_LIO_LICurvature-dependent feedback ensures robust and optimized hook shape C_LI

plant biology↗

bioRxiv2026

Evolution of moss leaf-like organs through variations in deeply conserved developmental principles

Leaves and leaf-like organs with laminar structures and determinate growth arose multiple times independently in land plants. The cellular basis of leaf development is well characterized in flowering plants, and molecular studies have shown that the plant hormone auxin plays a central role in this process, orchestrating cellular growth and differentiation. Auxin is also crucial for the formation of phyllids, the leaf-like organs of bryophytes, yet its precise role in morphogenesis remains unclear. More broadly, whether similar developmental principles are shared across distantly related evolutionary lineages is unknown. Here, we combine live-imaging, genetics, pharmacological treatments, and modeling to investigate the cellular and molecular basis of phyllid development in the model moss Physcomitrium patens. By tracking phyllid morphogenesis from a single initial cell to full maturity, we uncover the cellular growth dynamics underlying organ development. We demonstrate that auxin spatially inhibits cell divisions and promotes cellular elongation and differentiation. However, unlike in vascular plants, moss PIN transporters do not participate in polar auxin transport during phyllid development but mainly reduce intracellular auxin concentration. These findings indicate that while auxins role in organogenesis is conserved, its transport mechanisms have diverged across land plants. Overall, our study reveals shared principles of planar organ morphogenesis, highlighting how the repeated deployment of similar developmental strategies, with lineage-specific variations, drove the convergent evolution of leaves and leaf-like organs. One-Sentence SummaryAuxin modulates a conserved developmental program in moss leaf-like organs by spatiotemporally controlling cell division and growth.

plant biology↗

bioRxiv2025

Understanding Shape and Residual Stress Dynamics in Rod-Like Plant Organs

Residual stresses are common in rod-like plant organs such as roots and shoots, arising from mechanical incompatibilities between tissues with differing intrinsic lengths. Although mechanical regulation of cell wall growth is well established, the role of internally generated stresses in organ-scale morphogenesis remains poorly understood. Here, we introduce a tractable theoretical framework that couples structural residual stresses to growth-driven shape dynamics. We represent rod-like organs as bundles of morphoelastic rods connected in parallel, each corresponding to a distinct concentric tissue layer. Assuming elastic strain-driven growth and rod-like symmetry, the resulting mechanical constraints yield transparent analytical relationships linking tissue heterogeneity to macroscopic observables such as axial strain rates, bending dynamics, and residual stress distributions. Using a minimal two-layer model representing the epidermis and inner tissues, we show how tissue incompatibilities can generate phenomena including effective autotropism, mechanical memory, and discontinuous growth dynamics following cell division. Overall, our framework demonstrates how residual stresses may contribute to plant morphogenesis and provides a foundation for future investigations of mechano-chemical growth control in plants.

biophysics↗

bioRxiv2023

Modulation of cell differentiation and growth dynamics underlie the shift from bud protection to light capture in cauline leaves

Plant organs have evolved into diverse shapes for specialized functions despite emerging as simple protrusions at the shoot apex. Cauline leaves serve both as photosynthetic organs and protective structures for emerging floral buds. However, the growth patterns underlying this dual function remain unknown. Here, we investigate the developmental dynamics shaping cauline leaves underlying their functional diversification from other laminar organs. We show that cauline leaves display a significant delay in overall elongation compared to rosette leaves. Using live imaging, we reveal that their functional divergence hinges on early modulation of the timing of cell differentiation and cellular growth rates. In contrast to rosette leaves and sepals, cell differentiation is delayed in cauline leaves, fostering extended proliferation, prolonged morphogenetic activity, and growth redistribution within the organ. Notably, cauline leaf growth is transiently suppressed during the early stages, keeping the leaf small and unfolded during the initiation of the first flowers. Our findings highlight the unique developmental timing of cauline leaves, underlying their shift from an early protective role to a later photosynthetic function. ONE SENTENCE SUMMARYThe dual function of the cauline leaf in protection and light capture is achieved during development through a delay of cell differentiation, growth redistribution, and transient growth decrease.

plant biology↗

bioRxiv2023

Competing differentiation gradients coordinate fruit morphogenesis

Morphogenesis requires the coordination of cellular behaviors along developmental axes1. In plants, gradients of growth and differentiation are typically established along a single longitudinal primordium axis to control organ shaping2. Here we combine quantitative live-imaging at cellular resolution with genetics, chemical treatments, and modeling to understand the formation of Arabidopsis thaliana female reproductive organ (gynoecium). We show that, contrary to other aerial organs, gynoecium shape is determined by two competing differentiation gradients positioned along two orthogonal axes. An early mediolateral gradient, dependent on meristematic activity in the medial domain, controls the valve morphogenesis while simultaneously restricting an auxin-dependent, longitudinal gradient to the style. This gradient competition serves to finetune the common developmental program governing organ morphogenesis to ensure the specialized function of the gynoecium3,4.

plant biology↗

bioRxiv2021

MorphoGraphX 2.0: Providing context for biological image analysis with positional information

Positional information is a central concept in developmental biology. In developing organs, positional information can be idealized as a local coordinate system that arises from morphogen gradients controlled by organizers at key locations. This offers a plausible mechanism for the integration of the molecular networks operating in individual cells into the spatially-coordinated multicellular responses necessary for the organization of emergent forms. Understanding how positional cues guide morphogenesis requires the quantification of gene expression and growth dynamics in the context of their underlying coordinate systems. Here we present recent advances in the MorphoGraphX software (Barbier de Reuille et al. eLife 2015;4:e05864) that implement a generalized framework to annotate developing organs with local coordinate systems. These coordinate systems introduce an organ-centric spatial context to microscopy data, allowing gene expression and growth to be quantified and compared in the context of the positional information thought to control them.

developmental biology↗

bioRxiv2017

Cells From The Same Lineage Switch From Reduction To Enhancement Of Size Variability In Arabidopsis Sepals

Organs form with remarkably consistent sizes and shapes during development, whereas a high variability in size and growth is observed at cell level. Given this contrast, it is unclear how such consistency at organ scale can emerge from cellular behavior. We examine the growth of cell lineages, or groups of cells that are the progeny of a single mother cell. At early stages of the lineage, we find that initially smaller lineages grow faster than the larger ones reducing variability in lineage size, a phenomenon we refer to as size uniformization. In contrast at later stages of the lineage, size variability is enhanced when initially larger cell lineages grow faster than the smaller ones. Our results imply that the cell lineage changes its growth pattern at a tipping point. Finally, we found that the growth heterogeneity of individual cells within a lineage is correlated with fast growth of the lineage. Consequently, fast growing lineages show greater cell growth heterogeneity, leading to uniformization in lineage size. Thus, cellular variability in growth contributes toward decreasing variability of cell lineages throughout the sepal.

developmental biology↗