Biology subjects

van der Gucht, J.

Publications and source records attributed to van der Gucht, J..

6 recordsLinked to original sources

bioRxiv2026

Surface-stabilized sub-micron condensates for compartmentalizing synthetic cells and enhanced enzyme kinetics

Living cells harbor numerous membraneless organelles (MOs), which are dynamic protein/nucleic acid assemblies responding to specific physicochemical triggers. Liquid-liquid phase separation (LLPS) plays a crucial role in their formation and activity. Inspired by the natural MOs that maintain their individual identities, this work presents a bioengineering strategy to generate LLPS-driven, isochemical MO populations using surfactant-like peptides that stabilize the MO interface. The result is highly stable, monodispersed, sub-{micro}m-sized MO populations, which are not only capable of compartmentalizing synthetic cells but also provide superior environments for enzymatic reactions. This is achieved using pH-responsive elastin-like polypeptides (PREs) as MOs and formulating an amphiphilic PRE-based peptide to stabilize the MO interface. Relative abundance of the surface-active peptide, as well as the rate of pH change, allows direct control over the MO size. Encapsulating these components within synthetic vesicles using a microfluidic platform leads to on-demand multi-compartmentalization via an external pH trigger. Lastly, a functional consequence of the acute size control is shown through a phosphatase reaction, where the highest reaction rate is observed in size-controlled MOs when compared to dilute environments and surfactant-free MOs. The presented strategy provides a new avenue for designing programmable MOs and thus achieve functional compartmentalization within synthetic cells.

bioengineering↗

bioRxiv2026

Plant actin networks are rapid mechano-adaptive scaffolds

The actin cytoskeleton is among the most highly conserved eukaryotic structures. In animal cells, actin plays a key role in mechanobiology, serving as a structural scaffold that shapes cellular mechanics and a mechanoresponsive network that reorganizes in response to mechanical cues. In plants, these roles are generally attributed to the cell wall and the microtubule cytoskeleton. This leaves the role of plant actin in mechanical responses largely unclear. Here, we ask whether a key actin feature that is essential for animal mechanobiology may also be conserved in plants. We use quantitative live-cell imaging and quantitative image analysis to show that plant actin networks are rapidly mechano-responsive. We find a quantitative correlation between the cellular distribution of cortical actin networks and cellular deformations induced by laser ablation. This process is rapid and completes within 2-4 minutes. We propose that this is an intrinsic physical property of crosslinked filamentous networks, as these findings can be reproduced in a physical model that lacks biological regulation. Moreover, actin networks also respond to different types of mechanical stresses: both osmotic treatment and squeezing lead to distinct changes in actin organization, distribution, and dynamics. Our findings show that plant actin networks form mechano-adaptive scaffolds that sense mechanical deformations and reorganize in response within just a few minutes. This gives rise to a picture of plants having a two-geared cytoskeletal mechano-response system in which microtubules mediate slow responses to subtle developmental stresses, whereas actin provides a rapid response to large and potentially damaging deformations.

plant biology↗

bioRxiv2025

On the stabilization of plant lipid droplets: Dynamic interplay between oleosins and phospholipids

As the central organelles of lipid and energy homeostasis in plant seeds, lipid droplets (LDs) consist of a neutral lipid core, decorated by phospholipids (prominently phosphatidylcholines, PCs) and surfactant-like proteins (mostly oleosins, OLs). So far, the dynamic interplay between PCs and OLs at the LD interface remains unclear. The presented work addresses this knowledge gap by reconstituting oil-in-water emulsions stabilized by OLs and PCs using microfluidic systems. Our results show that the resistance to droplet coalescence is primarily provided by OLs. We further reveal that the addition of PCs alters the assembly of OLs at the interface, reducing the OL network density and interfacial elasticity, thereby rendering a weaker interface. In conclusion, our study suggests complementary roles, with OLs acting as the primary stabilizers while PCs playing a destabilizing role. This contrast likely contributes to the observed metastability of LDs and can be exploited to design stimuli-responsive emulsions. HIGHLIGHTSO_LIOleosins form an interfacial network that stabilizes the oil-water interface. C_LIO_LIPhosphatidylcholines globally weaken the oleosin network and promote droplet coalescence. C_LIO_LIMicrofluidics enables controlled reconstitution and real-time analysis of lipid droplets. C_LIO_LIOleosin-phospholipid interplay explains lipid droplet metastability and can guide the design of bio-inspired emulsions. C_LI

biophysics↗

bioRxiv2025

Transgenerational polarity axis inheritance during Ceratopteris embryogenesis

For sexually reproducing organisms to pass on their genetic information, progeny must successfully establish. Various life history strategies have evolved, using either dispersal of large numbers of progeny or intensive nurturing of a few. Most plants use the former strategy, but ferns generate a single embryo in the exact same location as the mother, and it is unknown how progeny success is promoted, or how embryogenesis is adapted. By studying Ceratopteris richardii embryogenesis, we find that maternal tissues guide orientation of the early embryo body axis, thus aligning its root pole towards the homologous maternal rhizoids. We find that axis polarity inheritance is mediated by maternal tissue mechanical patterns, and thus identify a robust mechanism for progeny establishment as a nurturing strategy in plants.

plant biology↗

bioRxiv2023

Rapid Molecular Mechanotyping with Microfluidic Force Spectroscopy

Molecular mechanotyping, the quantification of changes in the stability of supramolecular interactions and chemical bonds under the action of mechanical forces, is an essential tool in the field of mechanochemistry. This is conventionally done in single-molecule force-spectroscopy (smFS) assays, for example with optical tweezers or Atomic Force Microscopy. While these techniques provide detailed mechanochemical insights, they are time-consuming, technically demanding and expensive; as a result, high-throughput screening of the mechanochemical properties of molecules of interest is challenging. To resolve this, we present a rapid, simple and low-cost mechanotyping assay: microfluidic force spectroscopy ({micro}FFS), which probes force-dependent bond stability by measuring the detachment of microparticles, bound to microfluidic channels by the interaction of interest, under hydrodynamic forcing. As this allows the simultaneous observation of hundreds of microparticles, we obtain a quantitative mechanotype in a single measurement, using readily available equipment. We validate our method by studying the stability of DNA duplexes, previously characterized through smFS. We further show that we can quantitatively describe the experimental data with simulations, which allows us to link the {micro}FFS data to single-bond mechanochemical properties. This opens the way to use ({micro}FFS) as a rapid molecular mechanotyping tool.

biophysics↗

bioRxiv2020

Long-term single-cell imaging and simulations of microtubules reveal driving forces for wall pattering during proto-xylem development

Plants are the tallest organisms on Earth; a feature sustained by solute-transporting xylem vessels in the plant vasculature. The xylem vessels are supported by strong cell walls that are assembled in intricate patterns. Cortical microtubules direct wall deposition and need to rapidly re-organize during xylem cell development. We established long-term live-cell imaging of single Arabidopsis cells undergoing proto-xylem trans-differentiation, resulting in spiral wall patterns, to investigate the microtubule re-organization. The initial disperse microtubule array rapidly readjusted into well-defined microtubule bands, which required local de-stabilization of individual microtubules in band-interspersing gap regions. Using extensive microtubule simulations, we could recapitulate the process in silico and found that local recruitment of microtubule-bound nucleation is critical for pattern formation, which we confirmed in vivo. Our simulations further indicated that the initial microtubule alignment impact microtubule band patterning. We confirmed this prediction using katanin mutants, which have microtubule organization defects, and uncovered active KATANIN recruitment to the forming microtubule bands. Our combination of quantitative microscopy and modelling outlines a framework towards a comprehensive understanding of microtubule re-organization during wall pattern formation.

plant biology↗