Cell wall integrity modulates HOOKLESS1 and PHYTOCHROME INTERACTING FACTOR4 expression controlling apical hook formation.

Formation of the apical hook in etiolated dicot seedlings results from differential growth in the hypocotyl apex and is tightly controlled by environmental cues and hormones, among which auxin and gibberellins (GAs) play an important role. Cell expansion is tightly regulated by the cell wall, but whether and how feedback from this structure contributes to hook development are still unclear. Here, we show that etiolated seedlings of the Arabidopsis (Arabidopsis thaliana) quasimodo2-1 (qua2) mutant, defective in pectin biosynthesis, display severe defects in apical hook formation and maintenance, accompanied by loss of asymmetric auxin maxima and differential cell expansion.

Endoreplication mediates cell size control via mechanochemical signaling from cell wall.

Endoreplication is an evolutionarily conserved mechanism for increasing nuclear DNA content (ploidy). Ploidy frequently scales with final cell and organ size, suggesting a key role for endoreplication in these processes. However, exceptions exist, and, consequently, the endoreplication-size nexus remains enigmatic.

Plant cell walls as mechanical signaling hubs for morphogenesis.

The instructive role of mechanical cues during morphogenesis is increasingly being recognized in all kingdoms. Patterns of mechanical stress depend on shape, growth and external factors. In plants, the cell wall integrates these three parameters to function as a hub for mechanical feedback.

A study of flotation-REST (restricted environmental stimulation therapy) as an insomnia treatment.

Objectives: Flotation-REST is a treatment for deep relaxation, where a person is contained in a stimuli-restricted environment and floats in water with high salt content. The aim was to investigate the effects from flotation-REST on people with insomnia diagnosis, as previous studies of flotation-REST have demonstrated some effects on sleep but have limitations regarding sample selections and sleep measures.

Material And Methods: Six participants were recruited through an outpatient psychiatry clinic and posters on a university campus.

External Mechanical Cues Reveal a Katanin-Independent Mechanism behind Auxin-Mediated Tissue Bending in Plants.

Tissue folding is a central building block of plant and animal morphogenesis. In dicotyledonous plants, hypocotyl folds to form hooks after seedling germination that protects their aerial stem cell niche during emergence from soil. Auxin response factors and auxin transport are reported to play a key role in this process.

Mechanochemical feedback mediates tissue bending required for seedling emergence.

Tissue bending is vital to plant development, as exemplified by apical hook formation during seedling emergence by bending of the hypocotyl. How tissue bending is coordinated during development remains poorly understood, especially in plants where cells are attached via rigid cell walls. Asymmetric distribution of the plant hormone auxin underlies differential cell elongation during apical hook formation.

Interplay between Cell Wall and Auxin Mediates the Control of Differential Cell Elongation during Apical Hook Development.

Differential growth plays a crucial role during morphogenesis [1-3]. In plants, development occurs within mechanically connected tissues, and local differences in cell expansion lead to deformations at the organ level, such as buckling or bending [4, 5]. During early seedling development, bending of hypocotyl by differential cell elongation results in apical hook structure that protects the shoot apical meristem from being damaged during emergence from the soil [6, 7].

Branching Regulator BRC1 Mediates Photoperiodic Control of Seasonal Growth in Hybrid Aspen.

Cessation of growth as winter approaches is a key adaptive trait for survival of perennial plants, such as long-lived trees native to boreal and temperate regions [1, 2]. The timing of growth cessation in these plants is controlled by photoperiodic cues. As shown recently, perception of growth-repressive short photoperiod (SP) mediated via components of circadian clock results in downregulation of the tree ortholog of Arabidopsis flowering regulator FLOWERING LOCUS T (FT), FT2 [3, 4].

Long-range mobile signals mediate seasonal control of shoot growth.

In perennial plants, seasonal shifts provide cues that control adaptive growth patterns of the shoot apex. However, where these seasonal cues are sensed and communicated to the shoot apex remains unknown. We demonstrate that systemic signals from leaves play key roles in seasonal control of shoot growth in model tree hybrid aspen.

Ethylene Regulates Differential Growth via BIG ARF-GEF-Dependent Post-Golgi Secretory Trafficking in Arabidopsis.

During early seedling development, the shoot apical meristem is protected from damage as the seedling emerges from soil by the formation of apical hook. Hook formation requires differential growth across the epidermis below the meristem in the hypocotyl. The plant hormones ethylene and auxin play key roles during apical hook development by controlling differential growth.

Enrichment of hydroxylated C24- and C26-acyl-chain sphingolipids mediates PIN2 apical sorting at trans-Golgi network subdomains.

The post-Golgi compartment trans-Golgi Network (TGN) is a central hub divided into multiple subdomains hosting distinct trafficking pathways, including polar delivery to apical membrane. Lipids such as sphingolipids and sterols have been implicated in polar trafficking from the TGN but the underlying mechanisms linking lipid composition to functional polar sorting at TGN subdomains remain unknown. Here we demonstrate that sphingolipids with α-hydroxylated acyl-chains of at least 24 carbon atoms are enriched in secretory vesicle subdomains of the TGN and are critical for de novo polar secretory sorting of the auxin carrier PIN2 to apical membrane of Arabidopsis root epithelial cells.

Promising effects of treatment with flotation-REST (restricted environmental stimulation technique) as an intervention for generalized anxiety disorder (GAD): a randomized controlled pilot trial.

Background: During Flotation-REST a person is floating inside a quiet and dark tank, filled with heated salt saturated water. Deep relaxation and beneficial effects on e.g.

Dual role of tree florigen activation complex component FD in photoperiodic growth control and adaptive response pathways.

A complex consisting of evolutionarily conserved FD, flowering locus T (FT) proteins is a regulator of floral transition. Intriguingly, FT orthologs are also implicated in developmental transitions distinct from flowering, such as photoperiodic control of bulbing in onions, potato tuberization, and growth cessation in trees. However, whether an FT-FD complex participates in these transitions and, if so, its mode of action, are unknown.

Journey to the cell surface--the central role of the trans-Golgi network in plants.

The secretion of proteins, lipids, and carbohydrates to the cell surface is essential for plant development and adaptation. Secreted substances synthesized at the endoplasmic reticulum pass through the Golgi apparatus and trans-Golgi network (TGN) en route to the plasma membrane via the conventional secretion pathway. The TGN is morphologically and functionally distinct from the Golgi apparatus.

Methoxetamine (MXE)--a phenomenological study of experiences induced by a "legal high" from the internet.

Methoxetamine (MXE), a ketamine analogue, is one of the new "legal highs" sold on the Internet. The aim of this qualitative study was to provide an initial understanding of what characterizes the experiences induced by MXE. Anonymously written reports (33 persons) on the effects of MXE were collected from public Internet forums and analyzed using the Empirical Phenomenological Psychological Method.

ECHIDNA-mediated post-Golgi trafficking of auxin carriers for differential cell elongation.

The plant hormone indole-acetic acid (auxin) is essential for many aspects of plant development. Auxin-mediated growth regulation typically involves the establishment of an auxin concentration gradient mediated by polarly localized auxin transporters. The localization of auxin carriers and their amount at the plasma membrane are controlled by membrane trafficking processes such as secretion, endocytosis, and recycling.

Repeated Liver Resection for Colorectal Liver Metastases: A Comparison with Primary Liver Resections concerning Perioperative and Long-Term Outcome.

Introduction. 60% of patients operated for colorectal liver metastases (CRLM) will develop recurrent disease and some may be candidates for a repeated liver resection. The study aimed to evaluate differences in intraoperative blood loss and complications comparing the primary and the repeated liver resection for metastases of colorectal cancer (CRC), as well as to evaluate differences in long-time follow-up.