scholarly journals SlERF52 Regulates SlTIP1;1 Expression to Accelerate Tomato Pedicel Abscission

2021 ◽  
Author(s):  
Rong Wang ◽  
Ruizhen Li ◽  
Lina Cheng ◽  
Xiaoyang Wang ◽  
Xin Fu ◽  
...  
Keyword(s):  
Ethylene Production ◽  
Cell Separation ◽  
Regulatory Networks ◽  
Turgor Pressure ◽  
Water Influx ◽  
Osmotic Water ◽  
Liquid Chromatography Tandem Mass ◽  
Auxin Flux ◽  
Underlying Mechanisms

Abstract Abscission of plant organs is induced by developmental signals and diverse environmental stimuli, and involves multiple regulatory networks, including biotic or abiotic stress-impaired auxin flux in the abscission zone (AZ). Depletion of auxin activates AZ ethylene production and triggers acceleration of abscission, a process that requires hydrogen peroxide (H2O2). However, the interaction between these networks and the underlying mechanisms that control abscission are poorly understood. Here, we found that expression of tonoplast intrinsic proteins (TIPs) which belong to the aquaporin (AQP) family in the AZ was important for tomato (Solanum lycopersicum) pedicel abscission. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) and in situ hybridization revealed that SlTIP1;1 was most abundant and specifically present in the tomato pedicel AZ. SlTIP1;1 localized in the plasma membrane and tonoplast. Knockout of SlTIP1;1 resulted in delayed abscission, whereas overexpression of SlTIP1;1 accelerated abscission. Further analysis indicated that SlTIP1;1 mediated abscission via gating of cytoplasmic H2O2 concentrations and osmotic water permeability (Pf). Elevated cytoplasmic levels of H2O2 caused a suppressed auxin signal in the early abscission stage and enhanced ethylene production during abscission. Furthermore, we found that increasing Pf was required to enhance the turgor pressure to supply the break force for AZ cell separation. Moreover, we observed that SlERF52 bound directly to the SlTIP1;1 promoter to regulate its expression, demonstrating a positive loop in which cytoplasmic H2O2 activates ethylene production, which activates SlERF52. This, in turn, induces SlTIP1;1, which leads to elevated cytoplasmic H2O2 and water influx.

scholarly journals Photochemically induced cyclic morphological dynamics via degradation of autonomously produced, self-assembled polymer vesicles

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Chenyu Lin ◽  
Sai Krishna Katla ◽  
Juan Pérez-Mercader
Keyword(s):  
Morphological Evolution ◽  
Chemical Degradation ◽  
Chemical Mechanism ◽  
Giant Vesicles ◽  
Water Influx ◽  
Physico Chemical ◽  
Osmotic Water ◽  
Periodic Growth ◽  
Oxygen Conditions ◽  
Self Assembled

AbstractAutonomous and out-of-equilibrium vesicles synthesised from small molecules in a homogeneous aqueous medium are an emerging class of dynamically self-assembled systems with considerable potential for engineering natural life mimics. Here we report on the physico-chemical mechanism behind a dynamic morphological evolution process through which self-assembled polymeric structures autonomously booted from a homogeneous mixture, evolve from micelles to giant vesicles accompanied by periodic growth and implosion cycles when exposed to oxygen under light irradiation. The system however formed nano-objects or gelation under poor oxygen conditions or when heated. We determined the cause to be photoinduced chemical degradation within hydrated polymer cores inducing osmotic water influx and the subsequent morphological dynamics. The process also led to an increase in the population of polymeric objects through system self-replication. This study offers a new path toward the design of chemically self-assembled systems and their potential application in autonomous material artificial simulation of living systems.

RyR1 exhibits lower gain of CICR activity than RyR3 in the SR: evidence for selective stabilization of RyR1 channel

2004 ◽  
Vol 287 (1) ◽  
pp. C36-C45 ◽  
Author(s):  
Takashi Murayama ◽  
Yasuo Ogawa
Keyword(s):  
Binding Sites ◽  
Skeletal Muscles ◽  
Specific Activity ◽  
Adenine Nucleotides ◽  
Minor Effect ◽  
Mammalian Skeletal Muscle ◽  
Selective Stabilization ◽  
Underlying Mechanisms ◽  
A Minor

We showed that frog α-ryanodine receptor (α-RyR) had a lower gain of Ca2+-induced Ca2+ release (CICR) activity than β-RyR in sarcoplasmic reticulum (SR) vesicles, indicating selective “stabilization” of the former isoform (Murayama T and Ogawa Y. J Biol Chem 276: 2953–2960, 2001). To know whether this is also the case with mammalian RyR1, we determined [3H]ryanodine binding of RyR1 and RyR3 in bovine diaphragm SR vesicles. The value of [3H]ryanodine binding (B) was normalized by the number of maximal binding sites (Bmax), whereby the specific activity of each isoform was expressed. This B/Bmax expression demonstrated that ryanodine binding of individual channels for RyR1 was <15% that for RyR3. Responses to Ca2+, Mg2+, adenine nucleotides, and caffeine were not substantially different between in situ and purified isoforms. These results suggest that the gain of CICR activity of RyR1 is markedly lower than that of RyR3 in mammalian skeletal muscle, indicating selective stabilization of RyR1 as is true of frog α-RyR. The stabilization was partly eliminated by FK506 and partly by solubilization of the vesicles with CHAPS, each of which was additive to the other. In contrast, high salt, which greatly enhances [3H]ryanodine binding, caused only a minor effect on the stabilization of RyR1. None of the T-tubule components, coexisting RyR3, or calmodulin was the cause. The CHAPS-sensitive intra- and intermolecular interactions that are common between mammalian and frog skeletal muscles and the isoform-specific inhibition by FKBP12, which is characteristic of mammals, are likely to be the underlying mechanisms.

scholarly journals Mitochondria Endoplasmic Reticulum Contact Sites (MERCs): Proximity Ligation Assay as a Tool to Study Organelle Interaction

2021 ◽  
Vol 9 ◽  
Author(s):  
Sara Benhammouda ◽  
Anjali Vishwakarma ◽  
Priya Gatti ◽  
Marc Germain
Keyword(s):  
Endoplasmic Reticulum ◽  
Fluorescence Probes ◽  
Proximity Ligation Assay ◽  
Proximity Ligation ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Membrane Contact ◽  
Endogenous Proteins ◽  
Underlying Mechanisms

Organelles cooperate with each other to regulate vital cellular homoeostatic functions. This occurs through the formation of close connections through membrane contact sites. Mitochondria-Endoplasmic-Reticulum (ER) contact sites (MERCS) are one of such contact sites that regulate numerous biological processes by controlling calcium and metabolic homeostasis. However, the extent to which contact sites shape cellular biology and the underlying mechanisms remain to be fully elucidated. A number of biochemical and imaging approaches have been established to address these questions, resulting in the identification of a number of molecular tethers between mitochondria and the ER. Among these techniques, fluorescence-based imaging is widely used, including analysing signal overlap between two organelles and more selective techniques such as in-situ proximity ligation assay (PLA). While these two techniques allow the detection of endogenous proteins, preventing some problems associated with techniques relying on overexpression (FRET, split fluorescence probes), they come with their own issues. In addition, proper image analysis is required to minimise potential artefacts associated with these methods. In this review, we discuss the protocols and outline the limitations of fluorescence-based approaches used to assess MERCs using endogenous proteins.

scholarly journals Quantitative analysis of glyphosate, glufosinate and AMPA in irrigation water by in situ derivatization–dispersive liquid–liquid microextraction combined with UPLC-MS/MS

2018 ◽  
Vol 10 (5) ◽  
pp. 554-561 ◽  
Author(s):  
Edgar Pinto ◽  
António Gomes Soares ◽  
Isabel M. P. L. V. O. Ferreira
Keyword(s):  
Irrigation Water ◽  
Ultra Performance Liquid Chromatography ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Aminomethylphosphonic Acid ◽  
Liquid Chromatography Tandem Mass ◽  
Novel Method ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

A novel method was developed for the sensitive, cheap and fast quantitation of glyphosate, glufosinate and aminomethylphosphonic acid (AMPA) in irrigation water by in situ derivatization and dispersive liquid–liquid microextraction (DLLME) combined with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS).

Preliminary Experimental Study of Warm Ultrasonic Impact-assisted Laser Metal Deposition

2021 ◽  
pp. 1-15
Author(s):  
Hanyu Song ◽  
Minglang Li ◽  
Muxuan Wang ◽  
Benxin Wu ◽  
Ze Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Solid Material ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Ultrasonic Impact Treatment ◽  
Post Process ◽  
Underlying Mechanisms ◽  
Manufacturing Time

Abstract A preliminary experimental study on “warm ultrasonic impact-assisted laser metal deposition” (WUI-LMD) is reported, and such a study is rare in literatures to the authors' knowledge. In WUI-LMD, an ultrasonic impact treatment (UIT) tip is placed near laser spot for in-situ treatment of laser-deposited warm solid material, and the UIT and LMD processes proceed simultaneously. Under the conditions investigated, it is found that in-situ UIT during WUI-LMD can be much more effective in reducing porosity than a post-process UIT. Possible underlying mechanisms are analyzed. WUI-LMD has a great potential to reduce defects and improve mechanical properties without increasing manufacturing time.

Plant Ecophysiology: Linking Pattern and Process—a Review

1997 ◽  
Vol 45 (2) ◽  
pp. 351
Author(s):  
Jann Williams ◽  
Derek Eamus
Keyword(s):  
Plant Ecophysiology ◽  
Elevated Atmospheric Co2 ◽  
Pattern And Process ◽  
Ecological Society ◽  
Technological Advances ◽  
Ecological Patterns ◽  
Underlying Mechanisms ◽  
Underlying Processes

Introduction The Symposium ‘Plant Ecophysiology: Linking Pattern and Process’ was held as part of the 1995 meeting of the Ecological Society of Australia (ESA). The aim of the Symposium was to highlight work that examined mechanisms underlying ecological patterns and linked them to ecological and/or evolutionary processes. Another aim was to expose ecologists to the methods available to examine the mechanistic and functional basis of the organisms and systems under study. Much early ecological research has been concerned with the description and classification of vegetation types, with relatively little effort devoted to understanding the underlying processes that determined distribution. A more quantitative approach based on knowledge of the underlying mechanisms can further improve understanding of systems. This was amply demonstrated in a Symposium on the effects of elevated atmospheric CO2 on vegetation dynamics, also held in conjunction with an ESA meeting (see papers in Australian Journal of Botany, Volume 40(2)). Recent technological advances have stimulated rapid progress in the field of ecophysiology and hence an increasing process-based understanding is developing. The 1995 Symposium was seen as an opportunity to highlight more recent work in what is a relatively new field in Australia (albeit a well-established field in Europe and America), especially in situ studies and research from relatively little studied areas like northern Australia. The response to the Symposium was encouraging, with 25 spoken papers and poster-papers presented. In this paper, some of the unifying aspects of the papers presented in the symposium are drawn together, and placed in the context of likely future developments in ecophysiology in Australia. Based on this analysis, future directions and gaps are identified.

scholarly journals Investigating tool engagement in groundwood pulping: finite element modelling and in-situ observations at the microscale

Holzforschung ◽  
2020 ◽  
Vol 74 (5) ◽  
pp. 477-487 ◽  
Author(s):  
Jenny Carlsson ◽  
Magnus Heldin ◽  
Per Isaksson ◽  
Urban Wiklund
Keyword(s):  
Finite Element ◽  
Numerical Models ◽  
X Ray ◽  
Tool Geometries ◽  
Commercial Use ◽  
X Ray Computed ◽  
In Situ Observations ◽  
Underlying Mechanisms

AbstractWith industrial groundwood pulping processes relying on carefully designed grit surfaces being developed for commercial use, it is increasingly important to understand the mechanisms occurring in the contact between wood and tool. We present a methodology to experimentally and numerically analyse the effect of different tool geometries on the groundwood pulping defibration process. Using a combination of high-resolution experimental and numerical methods, including finite element (FE) models, digital volume correlation (DVC) of synchrotron radiation-based X-ray computed tomography (CT) of initial grinding and lab-scale grinding experiments, this paper aims to study such mechanisms. Three different asperity geometries were studied in FE simulations and in grinding of wood from Norway spruce. We found a good correlation between strains obtained from FE models and strains calculated using DVC from stacks of CT images of initial grinding. We also correlate the strains obtained from numerical models to the integrity of the separated fibres in lab-scale grinding experiments. In conclusion, we found that, by modifying the asperity geometries, it is, to some extent, possible to control the underlying mechanisms, enabling development of better tools in terms of efficiency, quality of the fibres and stability of the groundwood pulping process.

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