Molecular and Environmental Regulation of Root Development

2019 ◽  
Vol 70 (1) ◽  
pp. 465-488 ◽  
Author(s):  
Hans Motte ◽  
Steffen Vanneste ◽  
Tom Beeckman
Keyword(s):  
Root Development ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Primary Root ◽  
Root Apical Meristem ◽  
Control Mechanisms ◽  
Root Branching ◽  
And Control ◽  
The Impact

In order to optimally establish their root systems, plants are endowed with several mechanisms to use at distinct steps during their development. In this review, we zoom in on the major processes involved in root development and detail important new insights that have been generated in recent studies, mainly using the Arabidopsis root as a model. First, we discuss new insights in primary root development with the characterization of tissue-specific transcription factor complexes and the identification of non-cell-autonomous control mechanisms in the root apical meristem. Next, root branching is discussed by focusing on the earliest steps in the development of a new lateral root and control of its postemergence growth. Finally, we discuss the impact of phosphate, nitrogen, and water availability on root development and summarize current knowledge about the major molecular mechanisms involved.

Rhizotaxis Modulation in Arabidopsis Is Induced by Diffusible Compounds Produced during the Cocultivation of Arabidopsis and the Endophytic Fungus Serendipita indica

2020 ◽  
Vol 61 (4) ◽  
pp. 838-850
Author(s):  
Aoi Inaji ◽  
Atsushi Okazawa ◽  
Taiki Taguchi ◽  
Masatoshi Nakamoto ◽  
Nao Katsuyama ◽  
...  
Keyword(s):  
Root System ◽  
Root Development ◽  
Endophytic Fungus ◽  
Molecular Mechanisms ◽  
Primary Root ◽  
Gus Expression ◽  
Chemical Signals ◽  
Auxin Response ◽  
Root Tips

Abstract Rhizotaxis is established under changing environmental conditions via periodic priming of lateral root (LR) initiation at the root tips and adaptive LR formation along the primary root (PR). In contrast to the adaptable LR formation in response to nutrient availability, there is little information on root development during interactions with beneficial microbes. The Arabidopsis root system is characteristically modified upon colonization by the root endophytic fungus Serendipita indica, accompanied by a marked stimulation of LR formation and the inhibition of PR growth. This root system modification has been attributed to endophyte-derived indole-3-acetic acid (IAA). However, it has yet to be clearly explained how fungal IAA affects the intrinsic LR formation process. In this study, we show that diffusible compounds (chemical signals) other than IAA are present in the coculture medium of Arabidopsis and S. indica and induce auxin-responsive DR5::GUS expression in specific sections within the pericycle layer. The DR5::GUS expression was independent of polar auxin transport and the major IAA biosynthetic pathways, implicating unidentified mechanisms responsible for the auxin response and LR formation. Detailed metabolite analysis revealed the presence of multiple compounds that induce local auxin responses and LR formation. We found that benzoic acid (BA) cooperatively acted with exogenous IAA to generate a local auxin response in the pericycle layer, suggesting that BA is one of the chemical signals involved in adaptable LR formation. Identification and characterization of the chemical signals will contribute to a greater understanding of the molecular mechanisms underlying adaptable root development and to unconventional technologies for sustainable agriculture.

scholarly journals Phony peach disease: past and present impact on the peach industry in the southeastern U.S.A

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Kendall A. Johnson ◽  
Clive H. Bock ◽  
Phillip M. Brannen
Keyword(s):  
New Technologies ◽  
Current Knowledge ◽  
Future Research ◽  
Management Options ◽  
Disease Epidemiology ◽  
Pathogen Diversity ◽  
Foundational Research ◽  
Global Threat ◽  
And Control ◽  
The Impact

Abstract Background Phony peach disease (PPD) is caused by the plant pathogenic bacterium Xylella fastidiosa subsp. multiplex (Xfm). Historically, the disease has caused severe yield loss in Georgia and elsewhere in the southeastern United States, with millions of PPD trees being removed from peach orchards over the last century. The disease remains a production constraint, and management options are few. Limited research has been conducted on PPD since the 1980s, but the advent of new technologies offers the opportunity for new, foundational research to form a basis for informed management of PPD in the U.S. Furthermore, considering the global threat of Xylella to many plant species, preventing import of Xfm to other regions, particularly where peach is grown, should be considered an important phytosanitary endeavor. Main topics We review PPD, its history and impact on peach production, and the eradication efforts that were conducted for 42 years. Additionally, we review the current knowledge of the pathogen, Xfm, and how that knowledge relates to our understanding of the peach—Xylella pathosystem, including the epidemiology of the disease and consideration of the vectors. Methods used to detect the pathogen in peach are discussed, and ramifications of detection in relation to management and control of PPD are considered. Control options for PPD are limited. Our current knowledge of the pathogen diversity and disease epidemiology are described, and based on this, some potential areas for future research are also considered. Conclusion There is a lack of recent foundational research on PPD and the associated strain of Xfm. More research is needed to reduce the impact of this pathogen on peach production in the southeastern U.S., and, should it spread internationally, wherever peaches are grown.

scholarly journals The Impact of Medium Chain and Polyunsaturated ω-3-Fatty Acids on Amyloid-β Deposition, Oxidative Stress and Metabolic Dysfunction Associated with Alzheimer´s Disease

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1991
Author(s):  
Janine Mett
Keyword(s):  
Oxidative Stress ◽  
Fatty Acids ◽  
Energy Metabolism ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Membrane Integrity ◽  
Amyloid Β ◽  
The Elderly ◽  
Medium Chain ◽  
The Impact

Alzheimer’s disease (AD), the most common cause of dementia in the elderly population, is closely linked to a dysregulated cerebral lipid homeostasis and particular changes in brain fatty acid (FA) composition. The abnormal extracellular accumulation and deposition of the peptide amyloid-β (Aβ) is considered as an early toxic event in AD pathogenesis, which initiates a series of events leading to neuronal dysfunction and death. These include the induction of neuroinflammation and oxidative stress, the disruption of calcium homeostasis and membrane integrity, an impairment of cerebral energy metabolism, as well as synaptic and mitochondrial dysfunction. Dietary medium chain fatty acids (MCFAs) and polyunsaturated ω-3-fatty acids (ω-3-PUFAs) seem to be valuable for disease modification. Both classes of FAs have neuronal health-promoting and cognition-enhancing properties and might be of benefit for patients suffering from mild cognitive impairment (MCI) and AD. This review summarizes the current knowledge about the molecular mechanisms by which MCFAs and ω-3-PUFAs reduce the cerebral Aβ deposition, improve brain energy metabolism, and lessen oxidative stress levels.

scholarly journals Insights into the Cellular and Molecular Mechanisms That Govern the Fracture-Healing Process: A Narrative Review

2021 ◽  
Vol 10 (16) ◽  
pp. 3554
Author(s):  
Dionysios J. Papachristou ◽  
Stavros Georgopoulos ◽  
Peter V. Giannoudis ◽  
Elias Panagiotopoulos
Keyword(s):  
Fracture Healing ◽  
Bone Repair ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Healing Process ◽  
Bone Architecture ◽  
Multi Stage ◽  
Stage Process ◽  
And Function ◽  
The Impact

Fracture-healing is a complex multi-stage process that usually progresses flawlessly, resulting in restoration of bone architecture and function. Regrettably, however, a considerable number of fractures fail to heal, resulting in delayed unions or non-unions. This may significantly impact several aspects of a patient’s life. Not surprisingly, in the past few years, a substantial amount of research and number of clinical studies have been designed, aiming at shedding light into the cellular and molecular mechanisms that regulate fracture-healing. Herein, we present the current knowledge on the pathobiology of the fracture-healing process. In addition, the role of skeletal cells and the impact of marrow adipose tissue on bone repair is discussed. Unveiling the pathogenetic mechanisms that govern the fracture-healing process may lead to the development of novel, smarter, and more effective therapeutic strategies for the treatment of fractures, especially of those with large bone defects.

scholarly journals Recent Advances in Surface Nanoengineering for Biofilm Prevention and Control. Part I: Molecular Basis of Biofilm Recalcitrance. Passive Anti-Biofouling Nanocoatings

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1230 ◽  
Author(s):  
Paul Cătălin Balaure ◽  
Alexandru Mihai Grumezescu
Keyword(s):  
Life Cycle ◽  
Molecular Mechanisms ◽  
Antimicrobial Agents ◽  
Current Knowledge ◽  
Emergent Properties ◽  
Bacterial Cells ◽  
Life Cycle Stages ◽  
Fouling Release ◽  
Biofilm Development ◽  
And Control

Medical device-associated infections are becoming a leading cause of morbidity and mortality worldwide, prompting researchers to find new, more effective ways to control the bacterial colonisation of surfaces and biofilm development. Bacteria in biofilms exhibit a set of “emergent properties”, meaning those properties that are not predictable from the study of free-living bacterial cells. The social coordinated behaviour in the biofilm lifestyle involves intricate signaling pathways and molecular mechanisms underlying the gain in resistance and tolerance (recalcitrance) towards antimicrobial agents as compared to free-floating bacteria. Nanotechnology provides powerful tools to disrupt the processes responsible for recalcitrance development in all stages of the biofilm life cycle. The present paper is a state-of-the-art review of the surface nanoengineering strategies currently used to design antibiofilm coatings. The review is structurally organised in two parts according to the targeted biofilm life cycle stages and molecular mechanisms intervening in recalcitrance development. Therefore, in the present first part, we begin with a presentation of the current knowledge of the molecular mechanisms responsible for increased recalcitrance that have to be disrupted. Further, we deal with passive surface nanoengineering strategies that aim to prevent bacterial cells from settling onto a biotic or abiotic surface. Both “fouling-resistant” and “fouling release” strategies are addressed as well as their synergic combination in a single unique nanoplatform.

The influence of behavioural and organisational characteristics on the success of international strategic alliances

2004 ◽  
Vol 21 (1) ◽  
pp. 17-52 ◽  
Author(s):  
Saleema Kauser ◽  
Vivienne Shaw
Keyword(s):  
Strategic Alliances ◽  
Strategic Alliance ◽  
Current Trend ◽  
Business Strategies ◽  
Control Mechanisms ◽  
Alliance Performance ◽  
Behavioural Characteristics ◽  
International Strategic Alliances ◽  
And Control ◽  
The Impact

With the current trend toward globalisation and the increasing competitive and technological challenges of today's environment the formation of international strategic alliances has become an important part of many firm's international business strategies. Experience with international strategic alliances has shown that they face a number of problems, which can often result in the termination of the alliance. This study, therefore, aims to assess the impact of both behavioural and organisational characteristics on the success of international strategic alliances. The results show that behavioural characteristics play a more significant role in explaining overall alliance performance compared to organisational characteristics. High levels of commitment, trust, coordination, interdependence and communication are found to be good predictors of international strategic alliance success. Conflict, meanwhile, is found to hamper good performance. By contrast organisational characteristics such as structure and control mechanisms are found not to strongly influence the success of international strategic alliances.

scholarly journals The impact of British public opinion on women’s relationships with American GIs in Gloucestershire 1942-1946.

2021 ◽  
Author(s):  
◽  
Abigail Murphy
Keyword(s):  
Public Opinion ◽  
Female Sexuality ◽  
Sexual Relationships ◽  
Primary Sources ◽  
Control Mechanisms ◽  
Sexual Agency ◽  
The Public ◽  
Women's Relationships ◽  
And Control ◽  
The Impact

The main focus of this study is to determine the impact of public opinion on women’s relationships with American GIs in Gloucestershire 1942-1946. This involves understanding the scope of the relationships that were had and how race determined the way women who fraternised with US troops were portrayed to the public. Its primary aim is to provide new understanding of a subject that is under researched in Gloucestershire. Much attention has been given to the presence and impact of American soldiers in the Britain during the Second World War. However, no study has directly focused on Gloucestershire. This thesis also aims to understand if public opinion regarding women’s relationships with American soldiers impacted their sexual agency. Two main methods are used, the textual analysis of primary sources and the use of oral history accounts. The research reveals that sexual relationships with American soldiers added to the existing apprehension that surrounded female sexuality. Many local women had relationships with American soldiers, which aggravated some members of the public and the local authorities, especially if the soldier was black. Young working-class girls and women were particularly singled out for their immoral behaviour towards the US troops. The research also reveals that women in Gloucestershire expressed indifference and defiance towards the often-disapproving public opinion and control mechanisms implemented to influence the sexual agency of women. This thesis contributes to women’s history in Gloucestershire, uncovering a period of the county’s history that until now has not been researched.

scholarly journals A Perturbation Platform System for Balance Testing and Rehabilitation Interventions

2020 ◽  
Author(s):  
Corey Pew ◽  
Soroosh Sadeh ◽  
Richard R. Neptune ◽  
Hao-Yuan Hsiao
Keyword(s):  
Single Mode ◽  
The United States ◽  
Original Position ◽  
Control Mechanisms ◽  
Home Setting ◽  
Balance Testing ◽  
Portable System ◽  
Platform System ◽  
And Control ◽  
The Impact

Abstract Background Falling is a leading cause of injury and death in the United States. Researchers and clinicians strive to identify and rehabilitate those at risk of falling in order to mitigate the impact of fall events and prevent future falls. Recently, perturbation-based balance testing and interventions have received increased attention, partly because reactive postural control responses triggered by perturbations are important for balance recovery during actual falls. However, current systems are limited by the need for multiple individuals to operate the device, downtime between trials to reset the perturbation and/or single mode functionality. To this end, we have developed a Perturbation Platform System that can induce perturbations in both vertical and angled directions. Results The system consists of two box platforms that can individually perform straight (25.4 mm, 50.8 mm and 76.2 mm) and angled (5°, 10°, and 15°) height changes while an individual is standing or walking overground. In addition, the system can automatically reset to the original position following perturbation. The platform achieves peak downward accelerations of 5.41 m/s2 during drop events that simulate sudden changes in foot-contact surfaces. Conclusions The novel system can be used in a laboratory setting to better understand balance response and control mechanisms. In addition, this portable system can be used in a clinical or home setting to provide perturbation-based balance exercises that aim to improve balance and mobility.

scholarly journals A chemical screen identifies a link between lipid metabolism and mRNA translation

2020 ◽  
Author(s):  
Alba Corman ◽  
Dimitris C. Kanellis ◽  
Maria Häggblad ◽  
Vanesa Lafarga ◽  
Jiri Bartek ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Mammalian Cells ◽  
Current Knowledge ◽  
Mrna Translation ◽  
Protein Translation ◽  
Sphingosine Kinases ◽  
Chemical Screen ◽  
Approved Drugs ◽  
The Impact

ABSTRACTmRNA translation is one of the most energy-demanding processes for living cells, alterations of which have been frequently documented in human disease. Using recently developed technologies that enable image-based quantitation of overall translation levels, we here conducted a chemical screen to evaluate how medically approved drugs, as well as drugs that are currently under development, influence overall translation levels. Consistent with current knowledge, inhibitors of the mTOR signaling pathway were the most represented class among translation suppresors. In addition, we identified that inhibitors of sphingosine kinases (SPHKs) also reduce mRNA translation levels independently of mTOR. Mechanistically this is explained by an effect of the compounds on the membranes of the endoplasmic reticulum, which activates the integrated stress response (ISR). Accordingly, the impact of SPHK inhibitors on translation is alleviated by the concomitant inhibition of ISR kinases. On the other hand, and despite the large number of molecules tested, our study failed to identify chemicals capable of substantially increasing mRNA translation, raising doubts on to what extent translation can be supra-physiologically stimulated in mammalian cells. In summary, our study provides the first comprehensive characterization of the effect of known drugs on protein translation and has helped to unravel a new link between lipid metabolism and mRNA translation in human cells.

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