Screening methods for thermotolerance in pollen.

Plant reproduction is highly susceptible to temperature stress. The development of the male gametophyte in particular represents a critical element in the reproductive cycle with high sensitivity to elevated temperatures. Various methods have been used to test the effect of temperature stress on pollen performance or to determine the degree of susceptibility of given species and genotypes.

Cell geometry regulates tissue fracture.

In vascular plants, the epidermal surfaces of leaves and flower petals often display cells with wavy geometries forming intricate jigsaw puzzle patterns. The prevalence and diversity of these complex epidermal patterns, originating from simple polyhedral progenitor cells, suggest adaptive significance. However, despite multiple efforts to explain the evolutionary drivers behind these geometrical features, compelling validation remains elusive.

Pectate lyase-like lubricates the male gametophyte's path toward its mating partner.

The pollen tube is an extension of the male gametophyte in plants and mediates sexual reproduction by delivering the sperm cells to the female gametophyte. To accomplish this task, the elongating pollen tube must break through the thick wall of the pollen grain and penetrate multiple pistillar tissues. Both processes require the loosening of cell wall material-that of the pollen intine and that of the apoplast of the transmitting tract.

Sub-optimal nutrient regime coupled with and sp. inoculation influences trichome density and cannabinoid profiles in drug-type .

remains under heavy legal restriction around the globe that prevents extensive investigations into agricultural applications for improving its development. This work investigates the potential of specific plant growth-promoting rhizobacteria (PGPR) to improve cannabinoid yield through increased trichome densities on floral organs, and to determine if sub-optimal environmental conditions would affect the outcomes of PGPR presence by altering plant development and cannabinoid profiles. Here, sp.

Seeing clearly - Plant anatomy through Katherine Esau's microscopy lens.

Describing, naming and understanding the tissues and cell types composing biological organisms underpin myriad research endeavours in the biosciences. This is obvious when the organismal structure is a direct subject of the investigation such as in analyses of structure-function relationships. However, it also applies when structure represents the context.

3D Visualization of Microtubules in Epidermal Pavement Cells.

The plant cytoskeleton is instrumental in cellular processes such as cell growth, differentiation, and immune response. Microtubules, in particular, play a crucial role in morphogenesis by governing the deposition of plant cell wall polysaccharides and, in consequence, the cell wall mechanics and cell shape. Scrutinizing the microtubule dynamics is therefore integral to understanding the spatiotemporal regulation of cellular activities.

Pollen tube invasive growth is promoted by callose.

Callose, a β-1,3-glucan, lines the pollen tube cell wall except for the apical growing region, and it constitutes the main polysaccharide in pollen tube plugs. These regularly deposited plugs separate the active portion of the pollen tube cytoplasm from the degenerating cell segments. They have been hypothesized to reduce the total amount of cell volume requiring turgor regulation, thus aiding the invasive growth mechanism.

Multiscale structural anisotropy steers plant organ actuation.

Leaf movement in vascular plants is executed by joint-like structures called pulvini. Many structural features of pulvini have been described at subcellular, cellular, and tissue scales of organization; however, how the characteristic hierarchical architecture of plant tissue influences pulvinus-mediated actuation remains poorly understood. To investigate the influence of multiscale structure on turgor-driven pulvinus movements, we visualized Mimosa pudica pulvinus morphology and anatomy at multiple hierarchical scales of organization and used osmotic perturbations to experimentally swell pulvini in incremental states of dissection.

Modeling the molecular structures and dynamics responsible for the remarkable mechanical properties of a plant cell wall.

The primary plant cell wall is a hydrated meshwork of polysaccharides that is strong enough to withstand large mechanical stresses imposed by turgor while remaining pliant in ways that permit growth. To understand how its macromolecular architecture produces its complex mechanical properties, Zhang . computationally assembled a realistic network of cellulose microfibrils, hemicellulose, and pectin.

Mechanosensitive ion channels contribute to mechanically evoked rapid leaflet movement in Mimosa pudica.

Mechanoperception, the ability to perceive and respond to mechanical stimuli, is a common and fundamental property of all forms of life. Vascular plants such as Mimosa pudica use this function to protect themselves against herbivory. The mechanical stimulus caused by a landing insect triggers a rapid closing of the leaflets that drives the potential pest away.

Cannabis Glandular Trichomes: A Cellular Metabolite Factory.

has been legalized for recreational use in several countries and medical use is authorized in an expanding list of countries; markets are growing internationally, causing an increase in demand for high quality products with well-defined properties. The key compounds of plants are cannabinoids, which are produced by stalked glandular trichomes located on female flowers. These trichomes produce resin that contains cannabinoids, such as tetrahydrocannabinolic acid and cannabidiolic acid, and an array of other secondary metabolites of varying degrees of commercial interest.

Cytoskeletal regulation of primary plant cell wall assembly.

The plant cell wall is an extracellular matrix that envelopes cells, gives them structure and shape, constitutes the interface with symbionts, and defends plants against external biotic and abiotic stress factors. The assembly of this matrix is regulated and mediated by the cytoskeleton. Cytoskeletal elements define where new cell wall material is added and how fibrillar macromolecules are oriented in the wall.

Microfluidics-Based Bioassays and Imaging of Plant Cells.

Many plant processes occur in the context of and in interaction with a surrounding matrix such as soil (e.g. root growth and root-microbe interactions) or surrounding tissues (e.

Assembly of a simple scalable device for micromechanical testing of plant tissues.

Tensile testing is widely used to evaluate the mechanical properties of biological materials including soft primary plant tissues. Commercially available platforms for tensile testing are often expensive and limited in customizability. In this chapter, we provide a guide for the assembly and use of a simple and low-cost micromechanical testing apparatus suitable for research and educational purposes.

Travel Less. Make It Worthwhile.

Academic travel has a substantial carbon footprint. The ongoing pandemic has propelled the development and adoption of technologies for online delivery of seminars and remote attendance at scientific conferences. This should not lead to the complete elimination of in-person events, but the scientific community must seize the opportunity to permanently change its modus operandi and reduce the impact of its activities on the environment.

Silicone Chambers for Pollen Tube Imaging in Microstructured In Vitro Environments.

Live cell imaging at high resolution of pollen tubes growing in vitro requires an experimental setup that maintains the elongated cells in a single optical plane and allows for controlled exchange of growth medium. As a low-cost alternative to lithography-based microfluidics, we developed a silicone-based spacer system that allows introducing spatial features and flexible design. These growth chambers can be cleaned and reused repeatedly.

Galvanotropic Chamber for Controlled Reorientation of Pollen Tube Growth and Simultaneous Confocal Imaging of Intracellular Dynamics.

Successful fertilization and seed set require the pollen tube to grow through several tissues, to change its growth orientation by responding to directional cues, and to ultimately reach the embryo sac and deliver the paternal genetic material. The ability to respond to external directional cues is, therefore, a pivotal feature of pollen tube behavior. In order to study the regulatory mechanisms controlling and mediating pollen tube tropic growth, a robust and reproducible method for the induction of growth reorientation in vitro is required.

Durotropic Growth of Pollen Tubes.

To reach the female gametophyte, growing pollen tubes must penetrate different tissues within the pistil, the female reproductive organ of a flower. Past research has identified various chemotropic cues that guide pollen tubes through the transmitting tract of the pistil, which represents the longest segment of its growth path. In addition, physical mechanisms also play a role in pollen tube guidance; however, these processes remain poorly understood.

Form Follows Function: How to Build a Deadly Trap.

The carnivorous plant Utricularia gibba forms cup-shaped leaflets to capture prey. Whitewoods et al. (2020) use computational modeling to simulate the formation of the trap's 3D geometry.

Mechanical Stress Initiates and Sustains the Morphogenesis of Wavy Leaf Epidermal Cells.

Pavement cells form wavy interlocking patterns in the leaf epidermis of many plants. We use computational mechanics to simulate the morphogenetic process based on microtubule organization and cell wall chemistry. Based on the in silico simulations and experimental evidence, we suggest that a multistep process underlies the morphogenesis of pavement cells.

Pectin Chemistry and Cellulose Crystallinity Govern Pavement Cell Morphogenesis in a Multi-Step Mechanism.

Simple plant cell morphologies, such as cylindrical shoot cells, are determined by the extensibility pattern of the primary cell wall, which is thought to be largely dominated by cellulose microfibrils, but the mechanism leading to more complex shapes, such as the interdigitated patterns in the epidermis of many eudicotyledon leaves, is much less well understood. Details about the manner in which cell wall polymers at the periclinal wall regulate the morphogenetic process in epidermal pavement cells and mechanistic information about the initial steps leading to the characteristic undulations in the cell borders are elusive. Here, we used genetics and recently developed cell mechanical and imaging methods to study the impact of the spatio-temporal dynamics of cellulose and homogalacturonan pectin distribution during lobe formation in the epidermal pavement cells of Arabidopsis () cotyledons.