scholarly journals Submergence deactivates wound-induced plant defence against herbivores

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Hyo-Jun Lee ◽  
Ji-Sun Park ◽  
Seung Yong Shin ◽  
Sang-Gyu Kim ◽  
Gisuk Lee ◽  
...  
Keyword(s):  
Gene Locus ◽  
Molecular Mechanisms ◽  
Plant Defence ◽  
Plant Responses ◽  
Crop Loss ◽  
Inhibitory Effects ◽  
Short Term ◽  
Wound Responses ◽  
Induced Plant Defence ◽  
Ethylene Signalling

Abstract Flooding is a common and critical disaster in agriculture, because it causes defects in plant growth and even crop loss. An increase in herbivore populations is often observed after floods, which leads to additional damage to the plants. Although molecular mechanisms underlying the plant responses to flooding have been identified, how plant defence systems are affected by flooding remains poorly understood. Herein, we show that submergence deactivates wound-induced defence against herbivore attack in Arabidopsis thaliana. Submergence rapidly suppressed the wound-induced expression of jasmonic acid (JA) biosynthesis genes, resulting in reduced JA accumulation. While plants exposed to hypoxia in argon gas exhibited similar reduced wound responses, the inhibitory effects were initiated after short-term submergence without signs for lack of oxygen. Instead, expression of ethylene-responsive genes was increased after short-term submergence. Blocking ethylene signalling by ein2-1 mutation partially restored suppressed expression of several wound-responsive genes by submergence. In addition, submergence rapidly removed active markers of histone modifications at a gene locus involved in JA biosynthesis. Our findings suggest that submergence inactivates defence systems of plants, which would explain the proliferation of herbivores after flooding.

Molecular Mechanisms of the Inhibitory Effects of Bupivacaine, Levobupivacaine, and Ropivacaine on Sarcolemmal Adenosine Triphosphate–sensitive Potassium Channels in the Cardiovascular System

2004 ◽  
Vol 101 (2) ◽  
pp. 390-398 ◽  
Author(s):  
Takashi Kawano ◽  
Shuzo Oshita ◽  
Akira Takahashi ◽  
Yasuo Tsutsumi ◽  
Yoshinobu Tomiyama ◽  
...  
Keyword(s):  
Cardiovascular System ◽  
Adenosine Triphosphate ◽  
Local Anesthetics ◽  
Molecular Mechanisms ◽  
Transmembrane Domain ◽  
Katp Channels ◽  
Inhibitory Effect ◽  
Amino Acid Residues ◽  
Sulfonylurea Receptor ◽  
Inhibitory Effects

Background Sarcolemmal adenosine triphosphate-sensitive potassium (KATP) channels in the cardiovascular system may be involved in bupivacaine-induced cardiovascular toxicity. The authors investigated the effects of local anesthetics on the activity of reconstituted KATP channels encoded by inwardly rectifying potassium channel (Kir6.0) and sulfonylurea receptor (SUR) subunits. Methods The authors used an inside-out patch clamp configuration to investigate the effects of bupivacaine, levobupivacaine, and ropivacaine on the activity of reconstituted KATP channels expressed in COS-7 cells and containing wild-type, mutant, or chimeric SURs. Results Bupivacaine inhibited the activities of cardiac KATP channels (IC50 = 52 microm) stereoselectively (levobupivacaine, IC50 = 168 microm; ropivacaine, IC50 = 249 microm). Local anesthetics also inhibited the activities of channels formed by the truncated isoform of Kir6.2 (Kir6.2 delta C36) stereoselectively. Mutations in the cytosolic end of the second transmembrane domain of Kir6.2 markedly decreased both the local anesthetics' affinity and stereoselectivity. The local anesthetics blocked cardiac KATP channels with approximately eightfold higher potency than vascular KATP channels; the potency depended on the SUR subtype. The 42 amino acid residues at the C-terminal tail of SUR2A, but not SUR1 or SUR2B, enhanced the inhibitory effect of bupivacaine on the Kir6.0 subunit. Conclusions Inhibitory effects of local anesthetics on KATP channels in the cardiovascular system are (1) stereoselective: bupivacaine was more potent than levobupivacaine and ropivacaine; and (2) tissue specific: local anesthetics blocked cardiac KATP channels more potently than vascular KATP channels, via the intracellular pore mouth of the Kir6.0 subunit and the 42 amino acids at the C-terminal tail of the SUR2A subunit, respectively.

scholarly journals Potassium: A Vital Regulator of Plant Responses and Tolerance to Abiotic Stresses

Agronomy ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 31 ◽  
Author(s):  
Mirza Hasanuzzaman ◽  
M. Bhuyan ◽  
Kamrun Nahar ◽  
Md. Hossain ◽  
Jubayer Mahmud ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Tolerance ◽  
Molecular Mechanisms ◽  
Abiotic Stress Tolerance ◽  
Ion Homeostasis ◽  
Enzyme Activation ◽  
Regulatory Function ◽  
Plant Responses ◽  
Plant Structure ◽  
Physiological Processes

Among the plant nutrients, potassium (K) is one of the vital elements required for plant growth and physiology. Potassium is not only a constituent of the plant structure but it also has a regulatory function in several biochemical processes related to protein synthesis, carbohydrate metabolism, and enzyme activation. Several physiological processes depend on K, such as stomatal regulation and photosynthesis. In recent decades, K was found to provide abiotic stress tolerance. Under salt stress, K helps to maintain ion homeostasis and to regulate the osmotic balance. Under drought stress conditions, K regulates stomatal opening and helps plants adapt to water deficits. Many reports support the notion that K enhances antioxidant defense in plants and therefore protects them from oxidative stress under various environmental adversities. In addition, this element provides some cellular signaling alone or in association with other signaling molecules and phytohormones. Although considerable progress has been made in understanding K-induced abiotic stress tolerance in plants, the exact molecular mechanisms of these protections are still under investigation. In this review, we summarized the recent literature on the biological functions of K, its uptake, its translocation, and its role in plant abiotic stress tolerance.

Elicitins' Oligomeric States Affect The Hypersensitive Response And Resistance In Tobacco

2021 ◽  
Author(s):  
Martin Solanský ◽  
Kamil Mikulášek ◽  
Martina Zapletalová ◽  
Marek Petřivalský ◽  
Annick Chiltz ◽  
...  
Keyword(s):  
Hypersensitive Response ◽  
Early Recognition ◽  
Tobacco Plant ◽  
Plant Defence ◽  
Microbial Pathogens ◽  
Plant Responses ◽  
Resistance Response ◽  
Basal Resistance ◽  
Pathogenesis Related Protein ◽  
Fast Activation

Abstract Successful plant defence against microbial pathogens is based on early recognition and fast activation of inducible responses. Key mechanisms include detection of microbe-associated molecular patterns by membrane-localized Pattern Recognition Receptors that induce a basal resistance response. A well-described model of such responses to pathogens involves interaction between Solanaceae plants with proteinaceous elicitors secreted by oomycetes, called elicitins. It has been hypothesised that elicitins' formation of oligomeric structures could be involved in their recognition and activation of defensive transduction cascades. In tests of this hypothesis reported here, using several approaches, we observed differences in tobacco plant responses induced by the elicitin β-cryptogein (β-CRY) and its homodimer (β-CRY DIM). We also found that the C-terminal domain of elicitins of other ELI clades plays a significant role in stabilization of their oligomeric structure and restraint in the cell wall. In addition, covalently crosslinking β-CRY DIM impaired formation of signalling complexes, thereby reducing its capacity to elicit the hypersensitive response and resistance in the host plant, with no significant changes in pathogenesis-related protein expression. The results illuminate the poorly understood role of elicitins' oligomeric structures in oomycetes' interaction with plants, by revealing details of effects of β-CRY dimerization on tobacco plants' recognition and defence responses.

Dexamethasone attenuates the modulatory effect of the insular cortex on the baroreflex in anesthetized rat

2021 ◽  
Author(s):  
Tatiana Sergeevna Tumanova ◽  
Tatiana Nikolaevna Кokurina ◽  
Galina Ivanovna Rybakova ◽  
Viacheslav G. Aleksandrov
Keyword(s):  
Arterial Pressure ◽  
Baroreflex Sensitivity ◽  
Insular Cortex ◽  
Neural Mechanism ◽  
Arterial Baroreflex ◽  
Inhibitory Effects ◽  
Short Term ◽  
Central Autonomic Network

The arterial baroreflex (BR) is an important neural mechanism for the stabilization of arterial pressure (AP). It is known that the insular cortex (IC) and other parts of the central autonomic network (CAN) are able to modulate the BR arc, altering baroreflex sensitivity (BRS). In addition, the sensitivity of the BR changes under the influence of hormones, in particular glucocorticoids (GC). It has been suggested that GC may influence BRS by altering the ability of the IC to modulate the BR. This hypothesis has been tested in experiments on rats anesthetized with urethane. It was found that microelectrostimulation of the visceral area in the left IC causes a short-term drop in AP, which is accompanied by bradycardia, and impairs BRS. The synthetic GC dexamethasone (DEX) did not significantly affect the magnitude of depressor responses but increased BRS and impaired the effect of IC stimulation on the BR. The results obtained confirm the hypothesis put forward and suggest that GC can attenuate the inhibitory effects of the IC on the BR arc, thereby enhancing the sensitivity of the BR.

The molecular mechanisms of curcumin’s inhibitory effects on cancer stem cells

2018 ◽  
Vol 120 (4) ◽  
pp. 4739-4747 ◽  
Author(s):  
Elham Zendehdel ◽  
Elham Abdollahi ◽  
Amir Abbas Momtazi‐Borojeni ◽  
Mitra Korani ◽  
Seyedeh Hoda Alavizadeh ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Molecular Mechanisms ◽  
Inhibitory Effects

scholarly journals Activated Expression of PHT Genes Contributes to Osmotic Stress Resistance under Low Phosphorus Levels in Malus

2018 ◽  
Vol 143 (6) ◽  
pp. 436-445
Author(s):  
Tingting Sun ◽  
Tingting Pei ◽  
Zhijun Zhang ◽  
Mingjun Li ◽  
Linlin Huang ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Stress Resistance ◽  
Molecular Mechanisms ◽  
Photosynthetic Parameters ◽  
Plant Responses ◽  
Malus Prunifolia ◽  
Physiological Indicators ◽  
Malus Sieversii ◽  
Low Phosphorus ◽  
Osmotic Stress Resistance

Osmotic adjustments play a fundamental role in plant responses to water deficit. For apple (Malus domestica) trees growing in the primary production areas of China, drought and low phosphorus (P) levels are the main sources of abiotic stress. Although tolerance to drought and low P are important breeding goals for cultivar improvement, there is little information on natural variation within Malus for these traits or the molecular mechanisms that may mediate tolerance. In this study, it was found that in plants grown under conditions of osmotic and low P stress, electrolyte leakage and photosynthetic parameters were significantly higher, but chlorophyll concentrations were lower compared with nonstressed plants. These physiological indicators revealed that, under low P condition, the order of osmotic stress resistance (high to low) was Malus sieversii (Ms) → Malus prunifolia (Mp) → Malus hupehensis (Mh). Expression of the phosphorus transporter genes PHT1;7, PHT1;12, and PHT2;1 in the roots and PHT1;12 and PHT4;5 in the leaves was positively correlated with plant osmotic resistance. It is proposed that the highly expressed PHT genes might improve P absorption and transport efficiency, resulting in the high osmotic stress resistance under low P level conditions in Malus species.

scholarly journals Altered Short-Term Synaptic Plasticity in Mice Lacking the Metabotropic Glutamate Receptor mGlu7

2002 ◽  
Vol 2 ◽  
pp. 730-737 ◽  
Author(s):  
Trevor J. Bushell ◽  
Gilles Sansig ◽  
Valerie J. Collett ◽  
Herman van der Putten ◽  
Graham L. Collingridge
Keyword(s):  
Synaptic Plasticity ◽  
Molecular Mechanisms ◽  
Pyramidal Neurons ◽  
Metabotropic Glutamate Receptor ◽  
Long Term Potentiation ◽  
Short Term ◽  
Metabotropic Glutamate ◽  
Term Potentiation ◽  
Commissural Pathway ◽  
Frequency Facilitation

Eight subtypes of metabotropic glutamate (mGlu) receptors have been identified of which two, mGlu5 and mGlu7, are highly expressed at synapses made between CA3 and CA1 pyramidal neurons in the hippocampus. This input, the Schaffer collateral-commissural pathway, displays robust long-term potentiation (LTP), a process believed to utilise molecular mechanisms that are key processes involved in the synaptic basis of learning and memory. To investigate the possible function in LTP of mGlu7 receptors, a subtype for which no specific antagonists exist, we generated a mouse lacking this receptor, by homologous recombination. We found that LTP could be induced in mGlu7-/- mice and that once the potentiation had reached a stable level there was no difference in the magnitude of LTP between mGlu7-/- mice and their littermate controls. However, the initial decremental phase of LTP, known as short-term potentiation (STP), was greatly attenuated in the mGlu7-/- mouse. In addition, there was less frequency facilitation during, and less post-tetanic potentiation following, a high frequency train in the mGlu7-/- mouse. These results show that the absence of mGlu7 receptors results in alterations in short-term synaptic plasticity in the hippocampus.

scholarly journals RNA sequencing reveals metabolic and regulatory changes leading to more robust fermentation performance during short-term adaptation of Saccharomyces cerevisiae to lignocellulosic inhibitors

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Marlous van Dijk ◽  
Peter Rugbjerg ◽  
Yvonne Nygård ◽  
Lisbeth Olsson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stress Response ◽  
Rna Sequencing ◽  
Molecular Mechanisms ◽  
Lignocellulosic Hydrolysate ◽  
Short Term ◽  
Down Regulation ◽  
Time Resolved ◽  
Second Generation Bioethanol ◽  
Short Term Adaptation

Abstract Background The limited tolerance of Saccharomyces cerevisiae to inhibitors is a major challenge in second-generation bioethanol production, and our understanding of the molecular mechanisms providing tolerance to inhibitor-rich lignocellulosic hydrolysates is incomplete. Short-term adaptation of the yeast in the presence of dilute hydrolysate can improve its robustness and productivity during subsequent fermentation. Results We utilized RNA sequencing to investigate differential gene expression in the industrial yeast strain CR01 during short-term adaptation, mimicking industrial conditions for cell propagation. In this first transcriptomic study of short-term adaption of S. cerevisiae to lignocellulosic hydrolysate, we found that cultures respond by fine-tuned up- and down-regulation of a subset of general stress response genes. Furthermore, time-resolved RNA sequencing allowed for identification of genes that were differentially expressed at 2 or more sampling points, revealing the importance of oxidative stress response, thiamin and biotin biosynthesis. furan-aldehyde reductases and specific drug:H+ antiporters, as well as the down-regulation of certain transporter genes. Conclusions These findings provide a better understanding of the molecular mechanisms governing short-term adaptation of S. cerevisiae to lignocellulosic hydrolysate, and suggest new genetic targets for improving fermentation robustness.

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