scholarly journals Mechanism and function of root circumnutation

2021 ◽  
Vol 118 (8) ◽  
pp. e2018940118 ◽  
Author(s):  
Isaiah Taylor ◽  
Kevin Lehner ◽  
Erin McCaskey ◽  
Niba Nirmal ◽  
Yasemin Ozkan-Aydin ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Root Growth ◽  
Histidine Kinase ◽  
Molecular Mechanisms ◽  
Root Tip ◽  
Hormone Signaling ◽  
Plant Establishment ◽  
Functional Importance ◽  
And Function ◽  
Auxin Influx Carrier

Early root growth is critical for plant establishment and survival. We have identified a molecular pathway required for helical root tip movement known as circumnutation. Here, we report a multiscale investigation of the regulation and function of this phenomenon. We identify key cell signaling events comprising interaction of the ethylene, cytokinin, and auxin hormone signaling pathways. We identify the gene Oryza sativa histidine kinase-1 (HK1) as well as the auxin influx carrier gene OsAUX1 as essential regulators of this process in rice. Robophysical modeling and growth challenge experiments indicate circumnutation is critical for seedling establishment in rocky soil, consistent with the long-standing hypothesis that root circumnutation facilitates growth past obstacles. Thus, the integration of robotics, physics, and biology has elucidated the functional importance of root circumnutation and uncovered the molecular mechanisms underlying its regulation.

scholarly journals Mechanism and function of root circumnutation

2020 ◽  
Author(s):  
Isaiah Taylor ◽  
Kevin Lehner ◽  
Erin McCaskey ◽  
Niba Nirmal ◽  
Yasemin Ozkan-Aydin ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Histidine Kinase ◽  
Molecular Mechanisms ◽  
Root Tip ◽  
Hormone Signaling ◽  
Wild Type ◽  
Plant Establishment ◽  
Functional Importance ◽  
And Function ◽  
Auxin Influx Carrier

Abstract:Early root growth is critical for plant establishment and survival. We have identified a molecular pathway required for oscillatory root tip movement known as circumnutation. Here we report a multiscale investigation of the regulation and function of this phenomenon. We identify key cell signaling events comprising interaction of the ethylene, cytokinin, and auxin hormone signaling pathways. We identify the gene Oryza sativa Histidine Kinase-1/OsHK1, as well as the auxin influx carrier gene OsAUX1, as essential regulators of this process in rice. Robophysical modelling demonstrated the benefits of tip movement for navigating past obstacles, prompting us to challenge mutant and wild-type plants with different substrates. Consistent with model behavior, root circumnutation facilitated exploration of a solid surface and promoted seedling establishment in rocky soil. Thus, the integration of robotics, physics and biology elucidated the functional importance of root circumnutation and uncovered the molecular mechanisms underlying its regulation.One sentence summaryCircumnutation facilitates root exploration.

scholarly journals Gluconacetobacter diazotrophicus Changes The Molecular Mechanisms of Root Development in Oryza sativa L. Growing Under Water Stress

2020 ◽  
Vol 21 (1) ◽  
pp. 333 ◽  
Author(s):  
Renata Silva ◽  
Luanna Filgueiras ◽  
Bruna Santos ◽  
Mariana Coelho ◽  
Maria Silva ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Drought Stress ◽  
Root Growth ◽  
Root Development ◽  
Molecular Mechanisms ◽  
Oryza Sativa L ◽  
Gluconacetobacter Diazotrophicus ◽  
Red Rice ◽  
Bacterial Inoculation ◽  
Rice Plants

Background: Inoculation with Gluconacetobacter diazotrophicus has shown to influence root development in red rice plants, and more recently, the induced systemic tolerance (IST) response to drought was also demonstrated. The goal of this study was to evaluate the inoculation effect of G. diazotrophicus strain Pal5 on the amelioration of drought stress and root development in red rice (Oryza sativa L.). Methods: The experimental treatments consist of red rice plants inoculated with and without strain Pal5 in presence and absence of water restriction. Physiological, biochemical, and molecular analyses of plant roots were carried out, along with measurements of growth and biochemical components. Results: The plants showed a positive response to the bacterial inoculation, with root growth promotion and induction of tolerance to drought. An increase in the root area and higher levels of osmoprotectant solutes were observed in roots. Bacterial inoculation increased the drought tolerance and positively regulated certain root development genes against the water deficit in plants. Conclusion: G. diazotrophicus Pal5 strain inoculation favored red rice plants by promoting various root growth and developmental mechanisms against drought stress, enabling root development and improving biochemical composition.

scholarly journals Chromatin-based reprogramming of a courtship regulator by concurrent pheromone perception and hormone signaling

2020 ◽  
Vol 6 (21) ◽  
pp. eaba6913 ◽  
Author(s):  
Songhui Zhao ◽  
Bryson Deanhardt ◽  
George Thomas Barlow ◽  
Paulina Guerra Schleske ◽  
Anthony M. Rossi ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Behavioral Plasticity ◽  
Social Experience ◽  
Hormone Signaling ◽  
Active Chromatin ◽  
Simultaneous Exposure ◽  
Reproductive Behaviors ◽  
Courtship Behaviors ◽  
And Function ◽  
Pheromone Perception

To increase fitness, animals use both internal and external states to coordinate reproductive behaviors. The molecular mechanisms underlying this coordination remain unknown. Here, we focused on pheromone-sensing Drosophila Or47b neurons, which exhibit age- and social experience–dependent increase in pheromone responses and courtship advantage in males. FruitlessM (FruM), a master regulator of male courtship behaviors, drives the effects of social experience and age on Or47b neuron responses and function. We show that simultaneous exposure to social experience and age-specific juvenile hormone (JH) induces chromatin-based reprogramming of fruM expression in Or47b neurons. Group housing and JH signaling increase fruM expression in Or47b neurons and active chromatin marks at fruM promoter. Conversely, social isolation or loss of JH signaling decreases fruM expression and increases repressive marks around fruM promoter. Our results suggest that fruM promoter integrates coincident hormone and pheromone signals driving chromatin-based changes in expression and ultimately neuronal and behavioral plasticity.

scholarly journals The Ca2+ sensor protein CMI1 fine tunes root development, auxin distribution and responses

2018 ◽  
Author(s):  
Ora Hazak ◽  
Elad Mamon ◽  
Meirav Lavy ◽  
Hasana Sternberg ◽  
Smrutisanjita Behera ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Development ◽  
Lateral Root ◽  
Developmental Plasticity ◽  
Molecular Mechanisms ◽  
Ectopic Expression ◽  
Growth Arrest ◽  
Root Hairs ◽  
Root Tip ◽  
Auxin Distribution

Signaling cross-talks between auxin, a regulator of plant development and Ca2+, a universal second messenger have been proposed to modulate developmental plasticity in plants. However, the underlying molecular mechanisms are largely unknown. Here we report that in Arabidopsis roots, auxin elicits specific Ca2+ signaling pattern that spatially coincide with the expression pattern of auxin-regulated genes. We identified the EF-hand protein CMI1 (Ca2+ sensor Modulator of ICR1) as an interactor of the ROP effector ICR1 (Interactor of Constitutively active ROP). CMI1 is monomeric in solution, changes its secondary structure at Ca2+ concentrations ranging from 10-9 to 10-8 M and its interaction with ICR1 is Ca2+ dependent, involving a conserved hydrophobic pocket. cmi1 mutants display an increased auxin response including shorter primary roots, longer root hairs, longer hypocotyls and altered lateral root formation while ectopic expression of CMI1 induces root growth arrest and reduced auxin responses at the root tip. When expressed alone, CMI1 is localized at the plasma membrane, the cytoplasm and in nuclei. Interaction of CMI1 and ICR1 results in exclusion of CMI1 from nuclei and suppression of the root growth arrest. CMI1 expression is directly upregulated by auxin while expression of auxin induced genes is enhanced in cmi1 concomitantly with repression of auxin induced Ca2+ increases in the lateral root cap and vasculature, indicating that CMI1 represses early auxin responses. Collectively, our findings identify a crucial function of Ca2+ signaling and CMI1 in root growth and suggest an auxin-Ca2+ regulatory feedback loop that fine tunes root development.

Globular C1q receptor (p33) binds and stabilizes pro-inflammatory MCP-1: a novel mechanism for regulation of MCP-1 production and function

2018 ◽  
Vol 475 (4) ◽  
pp. 775-786 ◽  
Author(s):  
Emma Anders ◽  
Daniel Nebel ◽  
Johannes Westman ◽  
Heiko Herwald ◽  
Bengt-Olof Nilsson ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Periodontal Ligament ◽  
Molecular Mechanisms ◽  
Periodontal Ligament Cells ◽  
Physical Interaction ◽  
Functional Importance ◽  
Vitro Assay ◽  
Human Periodontal Ligament Cells ◽  
And Function ◽  
The Impact

The protein gC1qR (globular C1q receptor), also named p33, was originally identified as a binding partner of the globular heads of C1q in the complement system. gC1qR/p33 is abundantly expressed in many cell types, but the functional importance of this protein is not completely understood. Here, we investigate the impact of gC1qR/p33 on the production and function of the pathophysiologically important chemokine monocyte chemoattractant protein-1 (MCP-1) and the underlying molecular mechanisms. Knockdown of gC1qR/p33 negatively regulated the production of MCP-1, but had no effect on the expression of transcript for MCP-1 in human periodontal ligament cells, suggesting a translational/post-translational mechanism of action. Laser scanning confocal microscopy showed considerable cytosolic co-localization of gC1qR/p33 and MCP-1, and co-immunoprecipitation disclosed direct physical interaction between gC1qR/p33 and MCP-1. Surface plasmon resonance analysis revealed a high-affinity binding (KD = 10.9 nM) between gC1qR/p33 and MCP-1. Using a transwell migration assay, we found that recombinant gC1qR/p33 enhances MCP-1-induced migration of human THP-1 monocytes, pointing to a functional importance of the interaction between gC1qR/p33 and MCP-1. An in vitro assay revealed a rapid turnover of the MCP-1 protein and that gC1qR/p33 stabilizes MCP-1, hence preventing its degradation. We propose that endogenous gC1qR/p33 physically interacts with MCP-1 causing stabilization of the MCP-1 protein and stimulation of its activity in human periodontal ligament cells, suggesting a novel gC1qR/p33-mediated pro-inflammatory mechanism of action.

A Mucin-Specific Protease Enables Molecular and Functional Analysis of Human Cancer-Associated Mucins

2018 ◽  
Author(s):  
Stacy A. Malaker ◽  
Kayvon Pedram ◽  
Michael J. Ferracane ◽  
Elliot C. Woods ◽  
Jessica Kramer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
High Resolution Mass Spectrometry ◽  
Human Cancer ◽  
Glycosylation Sites ◽  
Bacterial Protease ◽  
Specific Protease ◽  
To Come ◽  
And Function

<div> <div> <div> <p>Mucins are a class of highly O-glycosylated proteins that are ubiquitously expressed on cellular surfaces and are important for human health, especially in the context of carcinomas. However, the molecular mechanisms by which aberrant mucin structures lead to tumor progression and immune evasion have been slow to come to light, in part because methods for selective mucin degradation are lacking. Here we employ high resolution mass spectrometry, polymer synthesis, and computational peptide docking to demonstrate that a bacterial protease, called StcE, cleaves mucin domains by recognizing a discrete peptide-, glycan-, and secondary structure- based motif. We exploited StcE’s unique properties to map glycosylation sites and structures of purified and recombinant human mucins by mass spectrometry. As well, we found that StcE will digest cancer-associated mucins from cultured cells and from ovarian cancer patient-derived ascites fluid. Finally, using StcE we discovered that Siglec-7, a glyco-immune checkpoint receptor, specifically binds sialomucins as biological ligands, whereas the related Siglec-9 receptor does not. Mucin-specific proteolysis, as exemplified by StcE, is therefore a powerful tool for the study of glycoprotein structure and function and for deorphanizing mucin-binding receptors. </p> </div> </div> </div>

scholarly journals Mechanosensation and Mechanotransduction by Lymphatic Endothelial Cells Act as Important Regulators of Lymphatic Development and Function

2021 ◽  
Vol 22 (8) ◽  
pp. 3955
Author(s):  
László Bálint ◽  
Zoltán Jakus
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Mechanical Forces ◽  
Lymphatic Endothelial Cells ◽  
Lymphatic Development ◽  
And Function ◽  
The Impact

Our understanding of the function and development of the lymphatic system is expanding rapidly due to the identification of specific molecular markers and the availability of novel genetic approaches. In connection, it has been demonstrated that mechanical forces contribute to the endothelial cell fate commitment and play a critical role in influencing lymphatic endothelial cell shape and alignment by promoting sprouting, development, maturation of the lymphatic network, and coordinating lymphatic valve morphogenesis and the stabilization of lymphatic valves. However, the mechanosignaling and mechanotransduction pathways involved in these processes are poorly understood. Here, we provide an overview of the impact of mechanical forces on lymphatics and summarize the current understanding of the molecular mechanisms involved in the mechanosensation and mechanotransduction by lymphatic endothelial cells. We also discuss how these mechanosensitive pathways affect endothelial cell fate and regulate lymphatic development and function. A better understanding of these mechanisms may provide a deeper insight into the pathophysiology of various diseases associated with impaired lymphatic function, such as lymphedema and may eventually lead to the discovery of novel therapeutic targets for these conditions.

scholarly journals Emerging Data on the Diversity of Molecular Mechanisms Involving C/D snoRNAs

2021 ◽  
Vol 7 (2) ◽  
pp. 30
Author(s):  
Laeya Baldini ◽  
Bruno Charpentier ◽  
Stéphane Labialle
Keyword(s):  
Ribosomal Rna ◽  
Molecular Mechanisms ◽  
Molecular Level ◽  
Accurate Description ◽  
Small Nucleolar Rnas ◽  
Age Of Maturity ◽  
Non Coding Rnas ◽  
And Function ◽  
Nucleolar Rnas

Box C/D small nucleolar RNAs (C/D snoRNAs) represent an ancient family of small non-coding RNAs that are classically viewed as housekeeping guides for the 2′-O-methylation of ribosomal RNA in Archaea and Eukaryotes. However, an extensive set of studies now argues that they are involved in mechanisms that go well beyond this function. Here, we present these pieces of evidence in light of the current comprehension of the molecular mechanisms that control C/D snoRNA expression and function. From this inventory emerges that an accurate description of these activities at a molecular level is required to let the snoRNA field enter in a second age of maturity.

Sign in / Sign up

Export Citation Format

Share Document