scholarly journals Link between Lipid Second Messengers and Osmotic Stress in Plants

2021 ◽  
Vol 22 (5) ◽  
pp. 2658
Author(s):  
Beatriz A. Rodas-Junco ◽  
Graciela E. Racagni-Di-Palma ◽  
Michel Canul-Chan ◽  
Javier Usorach ◽  
S. M. Teresa Hernández-Sotomayor
Keyword(s):  
Osmotic Stress ◽  
Protein Conformation ◽  
Membrane Lipids ◽  
Second Messengers ◽  
Physiological Responses ◽  
Plant Cells ◽  
Transient Molecules ◽  
Molecular Approaches ◽  
Extracellular Signal ◽  
Different Types

Plants are subject to different types of stress, which consequently affect their growth and development. They have developed mechanisms for recognizing and processing an extracellular signal. Second messengers are transient molecules that modulate the physiological responses in plant cells under stress conditions. In this sense, it has been shown in various plant models that membrane lipids are substrates for the generation of second lipid messengers such as phosphoinositide, phosphatidic acid, sphingolipids, and lysophospholipids. In recent years, research on lipid second messengers has been moving toward using genetic and molecular approaches to reveal the molecular setting in which these molecules act in response to osmotic stress. In this sense, these studies have established that second messengers can transiently recruit target proteins to the membrane and, therefore, affect protein conformation, activity, and gene expression. This review summarizes recent advances in responses related to the link between lipid second messengers and osmotic stress in plant cells.

scholarly journals In vitro Osmotic Stress Memory in Chrisanthemum hybridum: Structural and Physiological Responses

2017 ◽  
Vol 27 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Lidiia Samarina ◽  
Valentina Malyarovskaya ◽  
Yulija Abilfazova ◽  
Natalia Platonova ◽  
Kristina Klemeshova ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Relative Water Content ◽  
Soluble Protein ◽  
Growth Parameters ◽  
Physiological Responses ◽  
Proline Content ◽  
Stress Exposure ◽  
Stress Memory ◽  
Relative Water

Structural and physiological responses of chrysanthemum to repeated osmotic stress were studied. Plants were cultured for 2 weeks (for each stress1 and stress 2) on half MS supplemented with mannitol 100 mM (Treatment I) and 200 mM (Treatment II). First stress inhibited growth parameters stronger than second stress in treatment I. In treatment II both stress events strongly inhibited growth parameters of micro‐shoots. Proline content exceeded control 6 ‐ 8 times after 1st stress, and 2 ‐ 5 times after the 2nd stress in treatments I and II, respectively. Soluble protein was accumulated in leaves during both stress exposures, and 2 ‐ 2.5 times exceeded control after the 2nd stress. Relative water content in both treatments increased after the 2nd stress exposure. In treatment II chlorophyll а and carotenoids contents were 8.78 and 4.62 mg/g comparing to control (4.21 and 2.25 mg/g, respectively) after the 1st stress. But after the 2nd stress there was no difference with control.Plant Tissue Cult. & Biotech. 27(2): 161-169, 2017 (December)

scholarly journals PROGNOSTIC FACTORS IN SEVERE HEAD INJURY "A CLINICO RADIOLOGICAL STUDY"

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Dr. I. D. Chaurasia ◽  
Dr. Avais Ahmed Khan ◽  
Dr. Neeraj Mane ◽  
Dr. Prateek Malpani ◽  
Dr. M. C. Songara
Keyword(s):  
Heart Rate ◽  
Stress Responses ◽  
Severe Head Injury ◽  
Physiological Responses ◽  
Vital Signs ◽  
Behavioral Responses ◽  
Auditory Stimulation ◽  
Energy Demands ◽  
Significant Difference ◽  
Different Types

Overview:  Infants experience stressors. Stress responses in infants include physiological responses (HR and oxygen saturation) and behavioral responses (behavioral state, motor activity, and signs of behavioral distress). Modulation of the stress response in infants may reduce energy demands and enhance recovery. The characteristics of auditory stimulation provided by music differ from those of other types of auditory stimulation. The infants respond differently to music than to other random noises. This study was carried out to examine the effects of different types of music on vital signs of infants. Methodology: Thirty infants were included in the study. They were divided into two groups. Low and High pitched music was used with for two individual groups. The immediate effect was assessed through pre and post recordings for Heart rate, Reapiratory rate and O2 saturation level. Results: There was statistically significant change in Heart Rate, Respiratory Rate and O2 saturation individually. While comparing post data, except Heart Rate there was no significant difference found with both types of music. Conclusion: Low pitched music has better immediate effect than high pitched music Key words: High pitched music, Low pitched music, Infants

scholarly journals Endoplasmic reticulum-localized CCX2 is required for osmotolerance by regulating ER and cytosolic Ca2+ dynamics in Arabidopsis

2018 ◽  
Vol 115 (15) ◽  
pp. 3966-3971 ◽  
Author(s):  
Massimiliano Corso ◽  
Fabrizio G. Doccula ◽  
J. Romário F. de Melo ◽  
Alex Costa ◽  
Nathalie Verbruggen
Keyword(s):  
Endoplasmic Reticulum ◽  
Osmotic Stress ◽  
Shoot Growth ◽  
Plant Cells ◽  
Loss Of Function ◽  
Adaptive Responses ◽  
Triple Mutant ◽  
Gain Of Function ◽  
Salt And Osmotic Stress ◽  
Plant Mutant

Ca2+ signals in plant cells are important for adaptive responses to environmental stresses. Here, we report that the Arabidopsis CATION/Ca2+ EXCHANGER2 (CCX2), encoding a putative cation/Ca2+ exchanger that localizes to the endoplasmic reticulum (ER), is strongly induced by salt and osmotic stresses. Compared with the WT, AtCCX2 loss-of-function mutant was less tolerant to osmotic stress and displayed the most noteworthy phenotypes (less root/shoot growth) during salt stress. Conversely, AtCCX2 gain-of-function mutants were more tolerant to osmotic stress. In addition, AtCCX2 partially suppresses the Ca2+ sensitivity of K667 yeast triple mutant, characterized by Ca2+ uptake deficiency. Remarkably, Cameleon Ca2+ sensors revealed that the absence of AtCCX2 activity results in decreased cytosolic and increased ER Ca2+ concentrations in comparison with both WT and the gain-of-function mutants. This was observed in both salt and nonsalt osmotic stress conditions. It appears that AtCCX2 is directly involved in the control of Ca2+ fluxes between the ER and the cytosol, which plays a key role in the ability of plants to cope with osmotic stresses. To our knowledge, Atccx2 is unique as a plant mutant to show a measured alteration in ER Ca2+ concentrations. In this study, we identified the ER-localized AtCCX2 as a pivotal player in the regulation of ER Ca2+ dynamics that heavily influence plant growth upon salt and osmotic stress.

Diacylglycerols and PMA induce actin polymerization and distinct shape changes in lymphocytes: relation to fluid pinocytosis and locomotion

1989 ◽  
Vol 93 (3) ◽  
pp. 457-465
Author(s):  
H.U. Keller ◽  
V. Niggli ◽  
A. Zimmermann
Keyword(s):  
Actin Polymerization ◽  
Shape Change ◽  
Second Messengers ◽  
Cell Periphery ◽  
Response Curves ◽  
Blood Lymphocytes ◽  
Different Types ◽  
Net Uptake ◽  
Very High ◽  
Shape Changes

Shape changes have been determined in human blood lymphocytes stimulated with OAG, diC8, PMA, colchicine or the hexapeptide fNLPNTL in short-term assays (30 min). Distinct types of shape-change responses were observed. Colchicine was active in generating a relatively small proportion of polarized lymphocytes (front-tail polarity). OAG, diC8 and PMA produced different types of shape change (non-polar cells with surface projections), and these were closely associated with an increase in actin polymerization and a shift of F-actin into the projections at the cell periphery. The diacylglycerols OAG and diC8 produced biphasic dose-response curves leading to rounding up of cells at very high stimulant concentrations. PMA produced no comparable biphasic response when tested over a much wider concentration range. Though the nonpolar cells with surface projections generated by OAG, diC8 or PMA showed vigorous shape changes, they lacked significant locomotor activity. alpha-Phorbol, 4 alpha-PDD, lumicolchicine or fNLPNTL were inactive. Small blood lymphocytes stimulated by OAG, diC8 or PMA showed a very small increase in the net uptake of FITC-dextran by fluid pinocytosis. Unlike neutrophils, which show a high net uptake, lymphocytes did not concentrate FITC-dextran in large granules, indicating that they do not develop a ‘storage’ compartment in the form of large vesicles. However, small fluorescent spots were consistently found in at least a fraction of blood lymphocytes. The results indicate that stimulated surface movement may be instrumental in fluid pinocytosis. Diacylglycerols may act as second messengers to induce pinocytosis, shape changes and altered actin polymerization in lymphocytes.

scholarly journals Plant growth under suboptimal water conditions: early responses and methods to study them

2020 ◽  
Vol 71 (5) ◽  
pp. 1706-1722 ◽  
Author(s):  
Marieke Dubois ◽  
Dirk Inzé
Keyword(s):  
Plant Growth ◽  
Osmotic Stress ◽  
Stress Responses ◽  
Soil Drought ◽  
Growth Media ◽  
Plant Responses ◽  
Short Term ◽  
Environmental Constraint ◽  
Early Stress ◽  
Different Types

Abstract Drought stress forms a major environmental constraint during the life cycle of plants, often decreasing plant yield and in extreme cases threatening survival. The molecular and physiological responses induced by drought have been the topic of extensive research during the past decades. Because soil-based approaches to studying drought responses are often challenging due to low throughput and insufficient control of the conditions, osmotic stress assays in plates were developed to mimic drought. Addition of compounds such as polyethylene glycol, mannitol, sorbitol, or NaCl to controlled growth media has become increasingly popular since it offers the advantage of accurate control of stress level and onset. These osmotic stress assays enabled the discovery of very early stress responses, occurring within seconds or minutes following osmotic stress exposure. In this review, we construct a detailed timeline of early responses to osmotic stress, with a focus on how they initiate plant growth arrest. We further discuss the specific responses triggered by different types and severities of osmotic stress. Finally, we compare short-term plant responses under osmotic stress versus in-soil drought and discuss the advantages, disadvantages, and future of these plate-based proxies for drought.

Psychophysiological Stress Indicators In College Athletes: Comparison Of Physiological Responses With Different Types Of Stressors

2019 ◽  
Vol 51 (Supplement) ◽  
pp. 734-735
Author(s):  
Sara Ramirez-Hernandez ◽  
Victor Hugo Montejo-Lambaren ◽  
Alejandro Gaytan-Gonzalez ◽  
Juan R. Lopez-Taylor
Keyword(s):  
College Athletes ◽  
Physiological Responses ◽  
Stress Indicators ◽  
Psychophysiological Stress ◽  
Different Types

scholarly journals Terminal differentiation and senescence in the human melanocyte: repression of tyrosine-phosphorylation of the extracellular signal-regulated kinase 2 selectively defines the two phenotypes.

1994 ◽  
Vol 5 (4) ◽  
pp. 497-509 ◽  
Author(s):  
E E Medrano ◽  
F Yang ◽  
R Boissy ◽  
J Farooqui ◽  
V Shah ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Phorbol Esters ◽  
Second Messengers ◽  
Terminal Differentiation ◽  
Fold Increase ◽  
Nuclear Accumulation ◽  
Growth Promoters ◽  
Critical Pathway ◽  
Differentiated Cells ◽  
Extracellular Signal

Melanocytes are pigmented cells distributed in humans in several organs like the epidermis, the leptomeninges, the eye, and the inner ear. Epidermal melanocytes, whether derived from adult or neonatal skin, proliferate well in a medium supplemented with phorbol esters and other mitogens before they undergo senescence. Potent cAMP inducers like cholera toxin are also growth promoters for neonatal melanocytes but only transient growth stimulators for cells derived from adults. We used this cellular system to delineate biochemical pathways involved in proliferation and in terminal differentiation. Here we show that after a period of 4-8 wk of sustained proliferation in the presence of cholera toxin, the adult melanocytes became round, flat, and enlarged. These changes were associated with terminal growth and preceded by a five- to sixfold increase in cAMP levels and an 8- to 10-fold increase in melanin content. The simultaneous addition of phorbol esters and cholera toxin did not prevent cells from reaching terminal differentiation. Identified targets for phorbol esters are protein kinase C (PKC) and the mitogen-activated kinases (MAPKs), also called extracellular signal-regulated kinases (ERKs). PKC was found to be similarly regulated in proliferating and in terminally differentiated melanocytes. Proliferating melanocytes in early or late passage showed identical activation of the kinase ERK2. This kinase was rapidly phosphorylated upon phorbol 12-myristate 13-acetate (PMA) addition and specifically accumulated in the nucleus of the cells, whereas in unstimulated cells it had a perinuclear distribution. In contrast, senescent and terminally differentiated cells were unable to phosphorylate tyrosine residues of the ERK2 gene product in spite of presenting normal amounts of ERK2 protein. In addition, ERK2 did not show the nuclear accumulation observed in proliferating melanocytes after PMA activation and remained localized in the perinuclear area. These results demonstrate that senescent and terminally differentiated melanocytes share a common block in a critical pathway thought to integrate multiple intracellular signals transmitted by various second messengers and specifically prevent the continuation of the signal transduction cascade initiated by PMA activation of PKC.

Sign in / Sign up

Export Citation Format

Share Document