Biology subjects

Besten, M.

Publications and source records attributed to Besten, M..

7 recordsLinked to original sources

bioRxiv2026

P2K1 P2K2 Coordinate Early, Structure-Specific Mechanical Adaptations to Osmotic and Cell Wall Stress in Arabidopsis Roots

The cell wall and plasma membrane (PM) form the interface between a plant cell and its environment yet how their mechanical properties change in response to stress is poorly understood. Here we investigate how the mechanical properties of the cell wall, plasma membrane, and vacuole change in vivo in Arabidopsis thaliana roots in response to hyperosmotic stress and cell wall damage (CWD) using a solvatochromic dye, molecular rotors, and Brillouin microscopy. We observe initially dynamic changes in mechanical properties of the PM that are sensitive to both hyperosmotic stress and CWD, while the cell wall changes are limited and the vacuole adapts only after several hours. In the p2k1 p2k2 double mutant, lacking receptors for extracellular ATP perception, sorbitol-induced effects on PM mechanostasis and early isoxaben-induced increases in PM order are lost. Our results indicate that P2K1 and P2K2 are required to modulate adaptive changes in mechanical properties of the PM induced by hyperosmotic stress and CWD.

plant biology↗

bioRxiv2026

Plant Acupuncture: a low-cost and open-source device for local mechanical stimulation

Background: Mechanical signals are important regulators of cellular responses in plants. They guide plant development and can activate defense and repair mechanisms. Yet, the molecular mechanisms by which plants perceive, transduce, and interpret mechanical signals are still poorly understood. This is in part due to the lack of methods to apply local, precise and non-damaging mechanical forces to plant cells. Micro-indentation is highly suitable for this purpose, yet available instrumentation is often expensive and difficult to combine with high-resolution microscopy. Results: We designed an open-source and affordable modular indentation device, consisting of 3D printed elements, 3 commercially available piezo motors, and a variety of indentation needles. Due to its modularity, the setup can be readily adapted to meet experimental requirements and works on all microscopes with bespoke adaptors. We show that the setup can be used to explore both rapid and slower touch responses, exemplified by visualizing calcium waves and actin patches induced by touch. We also show that the setup is compatible with various plant species and tissues and can be combined with high-resolution functional imaging. Conclusions: The simple and flexible design of the indentation device presented in this paper ensures that any lab with a 3D printer can build their own setup at low cost and with minimal time investment. The system has a wide range of applications for live plant tissue, making indentation experiments and thereby plant mechanobiology studies, more accessible.

plant biology↗

bioRxiv2026

LipoTag: A minimal motif for live and functional imaging of plant cell membranes.

The plant plasma membrane is a highly dynamic structure that is crucial for cell compartmentalization, the maintenance of (bio)chemical gradients, signaling and cell growth and responses to stress. In plants, plasma membranes are tightly connected to the cell walls that encase them. These cell walls can act as diffusion barriers and prevent the use of a wide range of synthetic fluorescent probes that have been developed to study animal cell membranes, which lack a cell wall, with live functional imaging. Here, we introduce LipoTag, a minimal chemical motif that, upon chemical conjugation, transforms hydrophobic fluorophores into water-soluble, membrane-targeted probes that can permeate plant cell walls to reach their intended location. LipoTag uses a localized positive charge in combination with a short aliphatic spacer to direct cargo to the plasma membrane. We used LipoTag to develop a suite of membrane-specific fluorescent probes that work in walled organisms beyond the plant kingdom. In addition, we used LipoTag to develop functional reporters for the quantitative imaging of membrane density, lipid order and membrane oxidation in living plant tissues. LipoTag forms a modular platform for exploring the plant plasma membrane with a suite of contemporary imaging modalities.

plant biology↗

bioRxiv2025

The mechanical properties of Arabidopsis thaliana roots adapt dynamically during development and to stress

Mechanical properties of plant cells and tissues change dynamically, influencing plant growth, development, and interactions with the environment. Despite their central roles in plant life, current knowledge of how these properties change in vivo is very limited. Here we have combined Brillouin microscopy and molecular rotors to investigate stiffness, viscosity and porosity in living Arabidopsis thaliana seedling roots during differentiation and in response to stress and genetic manipulation. We found that mechanical properties change in a cell- and tissue-specific manner. The properties change dynamically during differentiation to support directional cell expansion. Cell-type-specific adaptations are induced within hours in response to stress or changes in cell wall metabolism. The findings form the foundation for future studies to characterize regulatory mechanisms linking biochemical signaling and mechanical properties.

plant biology↗

bioRxiv2024

H+ drives ultra-fast root-to-root responses to wounding

The plant-to-plant communication of damage is vital for plants to mount pre-emptive defensive responses in the face of threats. A variety of threats to the well-being of plants are found below ground; yet how plant roots activate inter-plant communication is largely unclear. Here we demonstrate that a wounded root rapidly releases protons (H+), that travel faster than any other "known" soluble biochemical signal due to a specialised diffusion mechanism. Within seconds after damage, cells in neighbouring unwounded roots sense the acidification and activate tissue-specific Ca2+ damage signalling. In turn, this triggers a differential growth response allowing the unwounded root to avoid the site of a potential threat. Our results reveal a non-canonical rapid response mechanism for inter-plant communication based on ultrafast proton diffusion.

plant biology↗

bioRxiv2024

CarboTag: a modular approach for live and functional imaging of plant cell walls

Plant cells are contained inside a rigid network of cell walls. Cell walls are highly dynamic structures that act both as a structural material and as a hub for a wide range of signaling processes. Despite its crucial role in all aspects of the plant life cycle, live dynamical imaging of the cell wall and its functional properties has remained challenging. Here, we introduce CarboTag, a modular toolbox for live functional imaging of plant walls. CarboTag relies on a small molecular motif, a pyridine boronic acid, that targets its cargo to the cell wall, is non-toxic and ensures rapid tissue permeation. We designed a suite of cell wall imaging probes based on CarboTag in any desired color for multiplexing. Moreover, we created new functional reporters for live quantitative imaging of key cell wall features: network porosity, cell wall pH and the presence of reactive oxygen species. CarboTag opens the way to dynamical and quantitative mapping of cell wall responses at subcellular resolution.

plant biology↗

bioRxiv2024

ATG8ylation of vacuolar membrane protects plants against cell wall damage

Vacuoles are essential for cellular metabolism, growth, and the maintenance of internal turgor pressure. They sequester lytic enzymes, ions, and secondary metabolites that, if leaked into the cytosol, could lead to cell death. Despite their pivotal roles, quality control pathways that safeguard vacuolar integrity remained elusive in plants. Here, we discovered a conserved vacuolar quality control (VQC) pathway that is activated upon cell wall damage in a turgor pressure dependent manner. Cell wall perturbations induce a distinct modification - ATG8ylation - on the vacuolar membrane (tonoplast) that is regulated by the V-ATPase and ATG8 conjugation machinery. Genetic disruption of tonoplast ATG8ylation impairs vacuolar integrity, leading to cell death. Together, our findings reveal a homeostatic pathway that preserves vacuolar integrity upon cell wall damage.

plant biology↗