scholarly journals Integration of computational modeling and quantitative cell physiology reveals central parameters for the brassinosteroid-regulated elongation growth along the axis of the Arabidopsis root tip

2021 ◽  
Author(s):  
Ruth Großeholz ◽  
Friederike Wanke ◽  
Nina Glöckner ◽  
Leander Rohr ◽  
Stefan Scholl ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Computational Modeling ◽  
Charge Compensation ◽  
Elongation Growth ◽  
Negative Regulator ◽  
Fine Tuning ◽  
Root Tip ◽  
Cell Physiology ◽  
Experimental Approaches ◽  
The Individual

AbstractBrassinosteroids (BR) are one of the key regulators of plant growth and development and have been the object of intense study. Whereas the individual components of the pathway have been well characterized experimentally, we employed computational modeling in combination with quantitative experiments to study the dynamics and regulation of the plasma membrane-localized fast BR response pathway in the epidermal cell layer along the Arabidopsis thaliana root axis that initiates early processes leading to cell elongation growth. The model, consisting of ordinary differential equations, comprises the BR induced hyperpolarization of the plasma membrane, the acidification of the apoplast and subsequent swelling of the cell wall. Utilizing this model and verified by experimental approaches, we demonstrate that the competence of the root epidermal cells for the physiological responses predominantly depends on the amount and activity of H+-ATPases in the plasma membrane. The model further predicted that an influx of cations is required to balance the shift of charges caused by the acidification of the apoplast. A potassium transporter was identified and characterized, which may fulfill this charge compensation. Lastly, we further specified in silico the role of the negative regulator BIR3 in the fine tuning of the cell physiological output.

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

scholarly journals A NOVEL ROLE OF PLASMA MEMBRANE CALCIUM ATPASE 4 AS A NEGATIVE-REGULATOR OF VEGF-INDUCED ANGIOGENESIS

Heart ◽  
2014 ◽  
Vol 100 (Suppl 4) ◽  
pp. A17.1-A17
Author(s):  
RR Baggott ◽  
A Alfranca ◽  
MD López-Maderuelo ◽  
TMA Mohamed ◽  
A Escolano ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Calcium Atpase ◽  
Negative Regulator ◽  
Plasma Membrane Calcium Atpase

AIR12, a b -type cytochrome of the plasma membrane of Arabidopsis thaliana is a negative regulator of resistance against Botrytis cinerea

Plant Science ◽  
2015 ◽  
Vol 233 ◽  
pp. 32-43 ◽  
Author(s):  
Alex Costa ◽  
Maria Raffaella Barbaro ◽  
Francesca Sicilia ◽  
Valeria Preger ◽  
Anja Krieger-Liszkay ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Plasma Membrane ◽  
Botrytis Cinerea ◽  
Negative Regulator

scholarly journals Rab23, a Negative Regulator of Hedgehog Signaling, Localizes to the Plasma Membrane and the Endocytic Pathway

Traffic ◽  
2003 ◽  
Vol 4 (12) ◽  
pp. 869-884 ◽  
Author(s):  
Timothy M. Evans ◽  
Charles Ferguson ◽  
Brandon J. Wainwright ◽  
Robert G. Parton ◽  
Carol Wicking
Keyword(s):  
Plasma Membrane ◽  
Hedgehog Signaling ◽  
Endocytic Pathway ◽  
Negative Regulator

Understanding Persistent Luminescence: Rare-Earth- and Eu2+-doped Sr2MgSi2O7

2014 ◽  
Vol 69 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Mika Lastusaari ◽  
Högne Jungner ◽  
Aleksei Kotlov ◽  
Taneli Laamanen ◽  
Lucas C. V. Rodrigues ◽  
...  
Keyword(s):  
Rare Earth ◽  
Band Gap ◽  
Charge Compensation ◽  
Band Gap Energy ◽  
Persistent Luminescence ◽  
Excitation Spectra ◽  
Co Doping ◽  
The Individual ◽  
Initial Intensity ◽  
The Eu

Similar to many other Eu2+,RE3+-co-doped persistent luminescence materials, for Sr2MgSi2O7:Eu2+,RE3+ the initial intensity and duration of persistent luminescence was also found to depend critically on the rare-earth (RE) co-doping. An enhancement of 1 - 2 orders of magnitude in these properties could be obtained by Dy3+ co-doping whereas total quenching of persistent luminescence resulted from the use of Sm3+ and Yb3+. To solve this drastic disparity, the effects of the individual RE3+ ions were studied with thermoluminescence (TL) spectroscopy to derive information about the formation of traps storing the excitation energy. The charge compensation defects were concluded to be the origin of the complex TL glow curve structure. The tuning of the band gap of the Sr2MgSi2O7 host and especially the position of the bottom of the conduction band due to the Eu2+,RE3+ co-doping was measured with the synchrotron radiation vacuum UV (VUV) excitation spectra of the Eu2+ dopant. The model based on the evolution of the band gap energy with RE3+ co-doping was found to explain the intensity and duration of the persistent luminescence.

scholarly journals Mask R-CNN Refitting Strategy for Plant Counting and Sizing in UAV Imagery

2020 ◽  
Vol 12 (18) ◽  
pp. 3015 ◽  
Author(s):  
Mélissande Machefer ◽  
François Lemarchand ◽  
Virginie Bonnefond ◽  
Alasdair Hitchins ◽  
Panagiotis Sidiropoulos
Keyword(s):  
Deep Learning ◽  
Fine Tuning ◽  
Aerial Images ◽  
Individual Plant ◽  
Low Density ◽  
Tracking Accuracy ◽  
Potato Plants ◽  
The Individual ◽  
Segmentation Task ◽  
Vision Algorithm

This work introduces a method that combines remote sensing and deep learning into a framework that is tailored for accurate, reliable and efficient counting and sizing of plants in aerial images. The investigated task focuses on two low-density crops, potato and lettuce. This double objective of counting and sizing is achieved through the detection and segmentation of individual plants by fine-tuning an existing deep learning architecture called Mask R-CNN. This paper includes a thorough discussion on the optimal parametrisation to adapt the Mask R-CNN architecture to this novel task. As we examine the correlation of the Mask R-CNN performance to the annotation volume and granularity (coarse or refined) of remotely sensed images of plants, we conclude that transfer learning can be effectively used to reduce the required amount of labelled data. Indeed, a previously trained Mask R-CNN on a low-density crop can improve performances after training on new crops. Once trained for a given crop, the Mask R-CNN solution is shown to outperform a manually-tuned computer vision algorithm. Model performances are assessed using intuitive metrics such as Mean Average Precision (mAP) from Intersection over Union (IoU) of the masks for individual plant segmentation and Multiple Object Tracking Accuracy (MOTA) for detection. The presented model reaches an mAP of 0.418 for potato plants and 0.660 for lettuces for the individual plant segmentation task. In detection, we obtain a MOTA of 0.781 for potato plants and 0.918 for lettuces.

scholarly journals Plasma membrane calcium ATPase regulates bone mass by fine-tuning osteoclast differentiation and survival

2012 ◽  
Vol 199 (7) ◽  
pp. 1145-1158 ◽  
Author(s):  
Hyung Joon Kim ◽  
Vikram Prasad ◽  
Seok-Won Hyung ◽  
Zang Hee Lee ◽  
Sang-Won Lee ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Bone Mass ◽  
Osteoclast Differentiation ◽  
Premenopausal Women ◽  
Fine Tuning ◽  
Bone Homeostasis ◽  
Regulatory Loop ◽  
And Function

The precise regulation of Ca2+ dynamics is crucial for proper differentiation and function of osteoclasts. Here we show the involvement of plasma membrane Ca2+ ATPase (PMCA) isoforms 1 and 4 in osteoclastogenesis. In immature/undifferentiated cells, PMCAs inhibited receptor activator of NF-κB ligand–induced Ca2+ oscillations and osteoclast differentiation in vitro. Interestingly, nuclear factor of activated T cell c1 (NFATc1) directly stimulated PMCA transcription, whereas the PMCA-mediated Ca2+ efflux prevented NFATc1 activation, forming a negative regulatory loop. PMCA4 also had an anti-osteoclastogenic effect by reducing NO, which facilitates preosteoclast fusion. In addition to their role in immature cells, increased expression of PMCAs in mature osteoclasts prevented osteoclast apoptosis both in vitro and in vivo. Mice heterozygous for PMCA1 or null for PMCA4 showed an osteopenic phenotype with more osteoclasts on bone surface. Furthermore, PMCA4 expression levels correlated with peak bone mass in premenopausal women. Thus, our results suggest that PMCAs play important roles for the regulation of bone homeostasis in both mice and humans by modulating Ca2+ signaling in osteoclasts.

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