Vacuoles are essential for cellular metabolism and 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 have remained elusive in plants.
View Article and Find Full Text PDFReactivation of cell division is crucial for the regeneration of damaged tissues, which is a fundamental process across all multicellular organisms. However, the mechanisms underlying the activation of cell division in plants during regeneration remain poorly understood. Here, we show that single-cell endodermal ablation generates a transient change in the local mechanical pressure on neighboring pericycle cells to activate patterned cell division that is crucial for tissue regeneration in Arabidopsis roots.
View Article and Find Full Text PDFSoft tissue sarcomas (STSs) are rare malignancies, with retroperitoneal soft tissue sarcoma (RPS) constituting 10%-15% of all STSs. RPS often presents late due to minimal early symptoms, typically requiring complete en-bloc resection for optimal survival outcomes. Achieving radical resection can be challenging due to the tumor's proximity to vital organs.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2025
Hypothesis: Films that develop compositional heterogeneity during drying offer a promising approach for achieving tailored functionalities. These functionalities can be realized by strategically directing different components during the drying process. One approach to achieve this is through spontaneous size segregation of colloidal particles.
View Article and Find Full Text PDFMicroswimmers are single-celled bodies powered by flagella. Typical examples are zoospores, dispersal agents of oomycete plant pathogens that are used to track down hosts and infect. Being motile, zoospores presumably identify infection sites using chemical cues such as sugars, alcohols and amino acids.
View Article and Find Full Text PDFBackground: Hepatocellular adenoma is a rare benign liver tumor. Typically, hepatocellular adenomas are solitary and are found in young women who use estrogen-containing contraceptives. The occurrence of multiple hepatocellular adenoma has been linked to higher body mass index, and as the prevalence of overweight increases, multiple hepatocellular adenomas are seen more often.
View Article and Find Full Text PDFThe devastating pathogen Botrytis cinerea infects a broad spectrum of host plants, causing great socio-economic losses. The necrotrophic fungus rapidly kills plant cells, nourishing their wall and cellular contents. To this end, necrotrophs secrete a cocktail of cell wall degrading enzymes, phytotoxic proteins and metabolites.
View Article and Find Full Text PDFAll primary chemical interactions weaken under mechanical stress, which imposes fundamental mechanical limits on the materials constructed from them. Biological materials combine plasticity with strength, for which nature has evolved a unique solution-catch bonds, supramolecular interactions that strengthen under tension. Biological catch bonds use force-gated conformational switches to convert weak bonds into strong ones.
View Article and Find Full Text PDFSoil salinity is a major contributor to crop yield losses. To improve our understanding of root responses to salinity, we developed and exploited a real-time salt-induced tilting assay. This assay follows root growth upon both gravitropic and salt challenges, revealing that root bending upon tilting is modulated by Na+ ions, but not by osmotic stress.
View Article and Find Full Text PDFInkjet printing is a ubiquitous consumer and industrial process that involves concomitant processes of droplet impact, wetting, evaporation, and imbibement into a substrate as well as consequential substrate rearrangements and remodeling. In this work, we perform a study on the interaction between ink dispersions of different composition on substrates of increasing complexity to disentangle the motion of the liquid from the dynamic response of the substrate. We print three variations of pigmented inks and follow the ensuing dynamics at millisecond and micron time and length scales until complete drying using a multiple scattering technique, laser speckle imaging (LSI).
View Article and Find Full Text PDFWhile nature extensively uses electrostatic bonding between oppositely charged polymers to assemble and stabilize materials, harnessing these interactions in synthetic systems has been challenging. Synthetic materials cross-linked with a high density of ionic bonds, such as polyelectrolyte complexes, only function properly when their charge interactions are attenuated in the presence of ample amounts of water; dehydrating these materials creates such strong Coulombic bonding that they become brittle, non-thermoplastic, and virtually impossible to process. We present a strategy to intrinsically moderate the electrostatic bond strengths in apolar polymeric solids by the covalent grafting of attenuator spacers to the charge carrying moieties.
View Article and Find Full Text PDFThe plant-signaling molecule auxin triggers fast and slow cellular responses across land plants and algae. The nuclear auxin pathway mediates gene expression and controls growth and development in land plants, but this pathway is absent from algal sister groups. Several components of rapid responses have been identified in Arabidopsis, but it is unknown if these are part of a conserved mechanism.
View Article and Find Full Text PDFThe drying of multi-component dispersions is a common phenomenon in a variety of everyday applications, including coatings, inks, processed foods, and cosmetics. As the solvent evaporates, the different components may spontaneously segregate laterally and/or in depth, which can significantly impact the macroscopic properties of the dried film. To obtain a quantitative understanding of these processes, high-resolution analysis of segregation patterns is crucial.
View Article and Find Full Text PDFPlant external surfaces are often covered by barriers that control the exchange of molecules, protect from pathogens and offer mechanical integrity. A key question is when and how such surface barriers are generated. Post-embryonic surfaces have well-studied barriers, including the cuticle, and it has been previously shown that the late Arabidopsis thaliana embryo is protected by an endosperm-derived sheath deposited onto a primordial cuticle.
View Article and Find Full Text PDFThe rice blast fungus Magnaporthe oryzae uses a pressurized infection cell called an appressorium to drive a rigid penetration peg through the leaf cuticle. The vast internal pressure of an appressorium is very challenging to investigate, leaving our understanding of the cellular mechanics of plant infection incomplete. Here, using fluorescence lifetime imaging of a membrane-targeting molecular mechanoprobe, we quantify changes in membrane tension in M.
View Article and Find Full Text PDFThe drying of a multi-component dispersion, such as water-based paint, ink and sunscreen to form a solid film, is a widespread process. Binary colloidal suspensions have proven capable of spontaneous layer formation through size segregation during drying. To design bespoke stratification patterns, a deeper understanding of how these emerge is crucial.
View Article and Find Full Text PDFFilamentous plant pathogens apply mechanical forces to pierce their hosts surface and penetrate its tissues. Devastating pathogens harness a specialized form of invasive tip growth to slice through the plant surface, wielding their hypha as a microscopic knife. Slicing requires a sharp hyphal tip that is not blunted at the site of the mechanical interaction.
View Article and Find Full Text PDFSingle stranded DNA (ssDNA), or another polyanion, can be mixed with polycations to form liquid-like complex coacervates. When the polycations are replaced by cationic-neutral diblock copolymers, complex coacervate core micelles (C3Ms) can be formed instead. In both complex coacervates and C3Ms, dynamics plays an important role.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2022
Fluorescent damage reporters that use mechanochemical activation of a covalent bond to elicit an optical signal are emerging tools in material mechanics as a means to access the nanoscale distribution of forces inside materials under stress. A promising class of damage reporters are tetraaryl succinonitriles (TASN), whose mechanical activation results in stable fluorescent radical species. However, in-depth insights into the molecular mechanics of TASN activation are absent, precluding their use as quantitative mechanoprobes.
View Article and Find Full Text PDF, causal agent of late blight in potato and tomato, remains challenging to control. Unravelling its biomechanics of host invasion, and its response to mechanical and chemical stress, could provide new handles to combat this devastating pathogen. Here we introduce two fluorescent molecular sensors, CWP-BDP and NR12S, that reveal the micromechanical response of the cell wall-plasma membrane continuum in during invasive growth and upon chemical treatment.
View Article and Find Full Text PDFBackground/objectives: Complications after pancreatoduodenectomy (PD) lead to unplanned readmissions (UR), with a two- to threefold increase in admission costs. In this study, we aimed to create an understanding of the costs of complications and UR in this patient group. Furthermore, we aimed to generate a detailed cost overview that can be used to build a theoretical model to calculate the cost efficacy for prehabilitation.
View Article and Find Full Text PDFHow reproducible body patterns emerge from the collective activity of individual cells is a key question in developmental biology. Plant cells are encaged in their walls and unable to migrate. Morphogenesis thus relies on directional cell division, by precise positioning of division planes, and anisotropic cellular growth, mediated by regulated mechanical inhomogeneity of the walls.
View Article and Find Full Text PDFUnderstanding phenomena such as evaporation and imbibition of picoliter droplets into porous substrates is crucial in printing industry to achieve a higher printing quality and print speed. After printing, the residual pigment must remain fixed at the desired location on a substrate and be of a desired volume to yield a high resolution and vibrantly printed page that has become the expectation of modern printing technology. Current research entails not only chemical composition of the ink but also how this links to the dynamics and interactions that occur between the ink and the substrate at every stage of the printed spot formation, including evaporation, wetting, and imbibition.
View Article and Find Full Text PDFPhytophthora species, classified as oomycetes, are among the most destructive plant pathogens worldwide and pose a substantial threat to food security. Plant pathogens have developed various methods to breach the cuticle and walls of plant cells. For example, plant-pathogenic fungi use a 'brute-force' approach by producing a specialized and fortified invasion organ to generate invasive pressures.
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