Publications by authors named "Alex Costa"

MID1-COMPLEMENTING ACTIVITY (MCA) is a land plant-specific, plasma membrane protein, and Ca2+ signaling component that responds to exogenous mechanical stimuli, such as touch, gravity, and hypotonic-osmotic stress, in various plant species. MCA is essential for cell proliferation and differentiation during growth and development in rice (Oryza sativa) and maize (Zea mays). However, the mechanism by which MCA mediates cell proliferation and differentiation via Ca2+ signaling remains unknown.

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Plants regulate gas exchange with the environment and modulate transpirational water flow through guard cells, which set the aperture of the stomatal pores. External and internal stimuli are detected by guard cells and integrated into a signalling network that modulate turgor pressure and, hence, pore size. Pathogen-associated molecular patterns are among the stimuli that induce stomatal closure, to prevent pathogen entry through the pores, and this response, also referred to as stomatal immunity, is one of the hallmarks of PAMP-triggered immunity.

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This dataset includes spectra obtained through Raman spectroscopy of acetylsalicylic acid, paracetamol, and ibuprofen commercialized in San Lorenzo, Central Department of Paraguay. The pharmaceuticals were randomly purchased from pharmacies, official sales points, and street vendors, simulating purchases for self-consumption. These drugs were selected due to their high demand and consumption by the population, aiming to document and facilitate the identification of adulterations or alterations in their original structures caused by poor storage conditions.

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In this protocol, we present a noninvasive in planta bioimaging technique for the analysis of hydrogen peroxide (HO) and glutathione redox potential in adult Arabidopsis thaliana plants. The technique is based on the use of stereo fluorescence microscopy to image A. thaliana plants expressing the two genetically encoded fluorescent sensors roGFP2-Orp1 and Grx1-roGFP2.

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Article Synopsis
  • The hydrostatic skeleton of plants is formed by pressurized cells with strong walls, which rely on RAPID ALKALINIZATION FACTOR (RALF) peptides for assembly and expansion.
  • The RALF22 peptide plays a key role in root hair cell expansion by compacting pectin polymers and forming a complex with other proteins, triggering adaptive cellular responses.
  • This study reveals that RALF peptides serve both structural and signaling functions in plant cell wall organization, suggesting a broader application in various plant cell types.
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Introduction: In critically ill children, pain management is complex owing to cognitive development and the nature of hospitalisation in paediatric intensive therapy units. Although there are many protocols and guidelines for pain control via pharmacological interventions, non-pharmacological practices should also be explored and disseminated for their potential benefit.

Methods And Analysis: A systematic literature search will be performed using the following databases: Academic Search Premier, Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, Excerpta Medica Database, Virtual Health Library, Medical Literature Analysis and Retrieval System Online, ScienceDirect, Scopus, Web of Science Core Collection, Theses from , Dart Europe, Open Access Theses and Dissertations and grey literature from Google Scholar.

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The grapevine industry is of high economic importance in several countries worldwide. Its growing market demand led to an acceleration of the entire production processes, implying increasing use of water resources at the expense of environmental water balance and the hydrological cycle. Furthermore, in recent decades climate change and the consequent expansion of drought have further compromised water availability, making current agricultural systems even more fragile from ecological and economical perspectives.

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Besides their central function in respiration, plant mitochondria play a crucial role in maintaining cellular homeostasis during stress by providing "retrograde" feedback to the nucleus. Despite the growing understanding of this signaling network, the nature of the signals that initiate mitochondrial retrograde regulation (MRR) in plants remains unknown. Here, we investigated the dynamics and causative relationship of a wide range of mitochondria-related parameters for MRR, using a combination of Arabidopsis fluorescent protein biosensor lines, in vitro assays, and genetic and pharmacological approaches.

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Upon exposure to light, etiolated Arabidopsis seedlings form adventitious roots (AR) along the hypocotyl. While processes underlying lateral root formation are studied intensively, comparatively little is known about the molecular processes involved in the initiation of hypocotyl AR. AR and LR formation were studied using a small molecule named Hypocotyl Specific Adventitious Root INducer (HYSPARIN) that strongly induces AR but not LR formation.

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Electrical signals in plants are mediators of long-distance signaling and correlate with plant movements and responses to stress. These signals are studied with single surface electrodes that cannot resolve signal propagation and integration, thus impeding their decoding and link to function. Here, we developed a conformable multielectrode array based on organic electronics for large-scale and high-resolution plant electrophysiology.

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To investigate the role of intracellular Ca signaling in the perception and response mechanisms to light in unicellular microalgae, the genetically encoded ratiometric Ca indicator Yellow Cameleon (YC3.6) was expressed in the model organism for green algae Chlamydomonas reinhardtii, targeted to cytosol, chloroplast, and mitochondria. Through in vivo single-cell confocal microscopy imaging, light-induced Ca signaling was investigated in different conditions and different genotypes, including the photoreceptors mutants phot and acry.

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Purpose: RPH3A encodes a protein involved in the stabilization of GluN2A subunit of N-methyl-D-aspartate (NMDA)-type glutamate receptors at the cell surface, forming a complex essential for synaptic plasticity and cognition. We investigated the effect of variants in RPH3A in patients with neurodevelopmental disorders.

Methods: By using trio-based exome sequencing, GeneMatcher, and screening of 100,000 Genomes Project data, we identified 6 heterozygous variants in RPH3A.

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Calcium (Ca)-ATPases are ATP-dependent enzymes that transport Ca ions against their electrochemical gradient playing the fundamental biological function of keeping the free cytosolic Ca concentration in the submicromolar range to prevent cytotoxic effects. In plants, type IIB autoinhibited Ca-ATPases (ACAs) are localised both at the plasma membrane and at the endomembranes including endoplasmic reticulum (ER) and tonoplast and their activity is primarily regulated by Ca-dependent mechanisms. Instead, type IIA ER-type Ca-ATPases (ECAs) are present mainly at the ER and Golgi Apparatus membranes and are active at resting Ca.

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DNA inverted repeats (IRs) are widespread across many eukaryotic genomes. Their ability to form stable hairpin/cruciform secondary structures is causative in triggering chromosome instability leading to several human diseases. Distance and sequence divergence between IRs are inversely correlated with their ability to induce gross chromosomal rearrangements (GCRs) because of a lesser probability of secondary structure formation and chromosomal breakage.

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In Arabidopsis thaliana, local wounding and herbivore feeding provoke leaf-to-leaf propagating Ca waves that are dependent on the activity of members of the glutamate receptor-like channels (GLRs). In systemic tissues, GLRs are needed to sustain the synthesis of jasmonic acid (JA) with the subsequent activation of JA-dependent signaling response required for the plant acclimation to the perceived stress. Even though the role of GLRs is well established, the mechanism through which they are activated remains unclear.

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Hydrogen sulfide (H2S) is a gaseous signaling molecule involved in numerous physiological processes in plants, including gas exchange with the environment through the regulation of stomatal pore width. Guard cells (GCs) are pairs of specialized epidermal cells that delimit stomatal pores and have a higher mitochondrial density and metabolic activity than their neighboring cells. However, there is no clear evidence on the role of mitochondrial activity in stomatal closure induction.

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Ca2+ signaling is central to plant development and acclimation. While Ca2+-responsive proteins have been investigated intensely in plants, only a few Ca2+-permeable channels have been identified, and our understanding of how intracellular Ca2+ fluxes is facilitated remains limited. Arabidopsis thaliana homologs of the mammalian channel-forming mitochondrial calcium uniporter (MCU) protein showed Ca2+ transport activity in vitro.

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Plant glutamate receptor-like channels (GLRs) are transmembrane proteins that allow the movement of several ions across membranes. In the model plant Arabidopsis, there are 20 GLR isoforms grouped in three clades and, since their discovery, it was hypothesized that GLRs were mainly involved in signaling processes. Indeed, in the last years, several pieces of evidence demonstrate different signaling roles played by GLRs, related to pollen development, sexual reproduction, chemotaxis, root development, regulation of stomatal aperture, and response to pathogens.

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Positive and counter-selectable markers have been successfully integrated as a part of numerous genetic assays in many model organisms. In this study, we investigate the mechanism of resistance to arginine analog canavanine and its applicability for genetic selection in Schizosaccharomyces pombe. Deletion of both the arginine permease gene cat1 and SPBC18H10.

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Stomatal movement is indispensable for plant growth and survival in response to environmental stimuli. Cytosolic Ca elevation plays a crucial role in ABA-induced stomatal closure during drought stress; however, to what extent the Ca movement across the plasma membrane from the apoplast to the cytosol contributes to this process still needs clarification. Here the authors identify (-)-catechin gallate (CG) and (-)-gallocatechin gallate (GCG), components of green tea, as inhibitors of voltage-dependent K channels which regulate K fluxes in Arabidopsis thaliana guard cells.

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K+/Na+ homeostasis is important for land plants, particularly under salt stress. In this study, the structure and ion transport properties of the high-affinity K+ transporter (HKT) of the liverwort Marchantia polymorpha were investigated. Only one HKT gene, MpHKT1, was identified in the genome of M.

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A distinct set of channels and transporters regulates the ion fluxes across the lysosomal membrane. Malfunctioning of these transport proteins and the resulting ionic imbalance is involved in various human diseases, such as lysosomal storage disorders, cancer, as well as metabolic and neurodegenerative diseases. As a consequence, these proteins have stimulated strong interest for their suitability as possible drug targets.

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The tools available to carry out in vivo analysis of Ca dynamics in plants are powerful and mature technologies that still require the proper controls.

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