NaCl-altered oxygen flux profiles and H+-ATPase activity in roots of two contrasting poplar species

2020 ◽  
Author(s):  
Xiuying Ma ◽  
Jinke Li ◽  
Chen Deng ◽  
Jian Sun ◽  
Jian Liu ◽  
...  
Keyword(s):  
Salt Stress ◽  
Atpase Activity ◽  
Mitochondrial Respiration ◽  
Populus Euphratica ◽  
Nacl Stress ◽  
Proton Pumps ◽  
O2 Uptake ◽  
Transient Kinetics ◽  
Root Cells ◽  
Cytochemical Analysis

Abstract Maintaining mitochondrial respiration is crucial for proving ATP for H+ pumps to continuously exclude Na+ under salt stress. NaCl-altered O2 uptake, mitochondrial respiration, and the relevance to H+-ATPase activity were investigated in two contrasting poplar species, Populus euphratica (salt-tolerant) and P. popularis 35–44 (salt-sensitive). Compared with P. popularis, P. euphratica roots exhibited a greater capacity to extrude Na+ under NaCl stress (150 mM). The cytochemical analysis with Pb(NO3)2 staining revealed that P. euphratica root cells retained higher H+ hydrolysis activity than the salt-sensitive poplar during a long-term (LT) of increasing salt stress (50 to 200 mM NaCl, 4 weeks). Long-sustained activation of proton pumps require long-lasting supply of energy (ATP), delivered by aerobic respiration. Taking advantage of the vibrating-electrodes technology combined with the use of membrane-tipped, polarographic oxygen microelectrodes, the species, spatial, and temporal differences in root O2 uptake were characterized under conditions of salt stress. Oxygen uptake upon NaCl shock (150 mM) was less declined in P. euphratica than in P. popularis, although the salt-induced transient kinetics were distinct from the drastic drop of O2 caused by hyperosmotic shock (255 mM mannitol). Short-term (ST) treatment (150 mM NaCl, 24 h) stimulated O2 influx in P. euphratica roots, and LT-treated P. euphratica displayed an increased O2 influx along root axis, whereas O2 influx declined with increasing salinity in P. popularis roots. The spatial localization of O2 influxes revealed that the apical zone was more susceptible than elongation region upon high NaCl (150, 200 mM) during ST and LT stress. Pharmacological experiments showed that the Na+ extrusion and H+-ATPase activity in salinized roots were correspondingly suppressed when O2 uptake was inhibited by a mitochondrial respiration inhibitor, NaN3. Therefore, we conclude that the stable mitochondrial respiration energized H+-ATPase of P. euphratica root cells for maintaining Na+ homeostasis under salt environments.

scholarly journals The signaling lipid PI(3,5)P2 stabilizes V1–Vo sector interactions and activates the V-ATPase

2014 ◽  
Vol 25 (8) ◽  
pp. 1251-1262 ◽  
Author(s):  
Sheena Claire Li ◽  
Theodore T. Diakov ◽  
Tao Xu ◽  
Maureen Tarsio ◽  
Wandi Zhu ◽  
...  
Keyword(s):  
Salt Stress ◽  
Atpase Activity ◽  
Human Disease ◽  
Proton Pumps ◽  
Disease Phenotypes ◽  
Reversible Dissociation ◽  
Signaling Mechanisms ◽  
Vacuolar Acidification ◽  
Direct Binding

Vacuolar proton-translocating ATPases (V-ATPases) are highly conserved, ATP-driven proton pumps regulated by reversible dissociation of its cytosolic, peripheral V1 domain from the integral membrane Vo domain. Multiple stresses induce changes in V1-Vo assembly, but the signaling mechanisms behind these changes are not understood. Here we show that certain stress-responsive changes in V-ATPase activity and assembly require the signaling lipid phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2). V-ATPase activation through V1-Vo assembly in response to salt stress is strongly dependent on PI(3,5)P2 synthesis. Purified Vo complexes preferentially bind to PI(3,5)P2 on lipid arrays, suggesting direct binding between the lipid and the membrane sector of the V-ATPase. Increasing PI(3,5)P2 levels in vivo recruits the N-terminal domain of Vo-sector subunit Vph1p from cytosol to membranes, independent of other subunits. This Vph1p domain is critical for V1-Vo interaction, suggesting that interaction of Vph1p with PI(3,5)P2-containing membranes stabilizes V1-Vo assembly and thus increases V-ATPase activity. These results help explain the previously described vacuolar acidification defect in yeast fab1∆ and vac14∆ mutants and suggest that human disease phenotypes associated with PI(3,5)P2 loss may arise from compromised V-ATPase stability and regulation.

scholarly journals Populus euphratica JRL Mediates ABA Response, Ionic and ROS Homeostasis in Arabidopsis under Salt Stress

2019 ◽  
Vol 20 (4) ◽  
pp. 815
Author(s):  
Huilong Zhang ◽  
Chen Deng ◽  
Jun Yao ◽  
Yan-Li Zhang ◽  
Yi-Nan Zhang ◽  
...  
Keyword(s):  
Salt Stress ◽  
Transgenic Plants ◽  
Transgenic Arabidopsis ◽  
Populus Euphratica ◽  
Nacl Stress ◽  
Callus Cultures ◽  
Schematic Model ◽  
Mesophyll Cells ◽  
Ros Homeostasis ◽  
Aba Response

Sodium chloride (NaCl) induced expression of a jacalin-related mannose-binding lectin (JRL) gene in leaves, roots, and callus cultures of Populus euphratica (salt-resistant poplar). To explore the mechanism of the PeJRL in salinity tolerance, the full length of PeJRL was cloned from P. euphratica and was transformed into Arabidopsis. PeJRL was localized to the cytoplasm in mesophyll cells. Overexpression of PeJRL in Arabidopsis significantly improved the salt tolerance of transgenic plants, in terms of seed germination, root growth, and electrolyte leakage during seedling establishment. Under NaCl stress, transgenic plants retained K+ and limited the accumulation of Na+. PeJRL-transgenic lines increased Na+ extrusion, which was associated with the upward regulation of SOS1, AHA1, and AHA2 genes encoding plasma membrane Na+/proton (H+) antiporter and H+-pumps. The activated H+-ATPases in PeJRL-overexpressed plants restricted the channel-mediated loss of K+ that was activated by NaCl-induced depolarization. Under salt stress, PeJRL–transgenic Arabidopsis maintained reactive oxygen species (ROS) homeostasis by activating the antioxidant enzymes and reducing the production of O2− through downregulation of NADPH oxidases. Of note, the PeJRL-transgenic Arabidopsis repressed abscisic acid (ABA) biosynthesis, thus reducing the ABA-elicited ROS production and the oxidative damage during the period of salt stress. A schematic model was proposed to show the mediation of PeJRL on ABA response, and ionic and ROS homeostasis under NaCl stress.

scholarly journals Populus euphratica WRKY1 binds the promoter of H+-ATPase gene to enhance gene expression and salt tolerance

2019 ◽  
Vol 71 (4) ◽  
pp. 1527-1539 ◽  
Author(s):  
Jun Yao ◽  
Zedan Shen ◽  
Yanli Zhang ◽  
Xia Wu ◽  
Jianhui Wang ◽  
...  
Keyword(s):  
Salt Stress ◽  
Promoter Region ◽  
Affinity Purification ◽  
Regulatory Region ◽  
Populus Euphratica ◽  
Luciferase Reporter ◽  
Proton Pumps ◽  
Tobacco Plants ◽  
Atpase Gene ◽  
Pumping Activity

Abstract Plasma membrane proton pumps play a crucial role in maintaining ionic homeostasis in salt-resistant Populus euphratica under saline conditions. High levels of NaCl (200 mM) induced PeHA1 expression in P. euphratica roots and leaves. We isolated a 2022 bp promoter fragment upstream of the translational start of PeHA1 from P. euphratica. The promoter–reporter construct PeHA1-pro::GUS was transferred to tobacco plants, demonstrating that β-glucuronidase activities increased in root, leaf, and stem tissues under salt stress. DNA affinity purification sequencing revealed that PeWRKY1 protein targeted the PeHA1 gene. We assessed the salt-induced transcriptional response of PeWRKY1 and its interaction with PeHA1 in P. euphratica. PeWRKY1 binding to the PeHA1 W-box in the promoter region was verified by a yeast one-hybrid assay, EMSA, luciferase reporter assay, and virus-induced gene silencing. Transgenic tobacco plants overexpressing PeWRKY1 had improved expression of NtHA4, which has a cis-acting W-box in the regulatory region, and improved H+ pumping activity in both in vivo and in vitro assays. We conclude that salt stress up-regulated PeHA1 transcription due to the binding of PeWRKY1 to the W-box in the promoter region of PeHA1. Thus, we conclude that enhanced H+ pumping activity enabled salt-stressed plants to retain Na+ homeostasis.

Molecular Characterization of a Tonoplast Na+/H+ Antiporter from Iris Lactea

2018 ◽  
Author(s):  
Qiang Guo ◽  
Xiaoxia Tian ◽  
Peichun Mao ◽  
Lin Meng
Keyword(s):  
Salt Stress ◽  
Transgenic Tobacco ◽  
Membrane Integrity ◽  
Nacl Stress ◽  
Proton Pumps ◽  
Transgenic Tobacco Plants ◽  
Tobacco Plants ◽  
Cell Membrane Integrity ◽  
Effective Strategies ◽  
Photosynthesis Efficiency

Na+ compartmentalization into vacuoles is one of the effective strategies for adaptation of halophytes to saline environments. The tonoplast Na+/H+ antiporter (NHX) has been proved to be involved in the compartmentalization of Na+ into vacuoles to alleviate Na+ toxicity in cytoplasm. However, the function of NHX in halophyte Iris lactea is still unclear under salt stress. In this study, a significant positive correlation was observed between Na+ accumulations and IlNHX expression levels in shoots and roots under different concentrations of NaCl (0-200 mM), indicating IlNHX might be involved in Na+ accumulation of I. lactea in response to salt stress. More important, IlNHX was specifically localized to the tonoplast. Transgenic tobacco plants expressing IlNHX grew better and showed higher salinity tolerance under salt (200 mM NaCl) stress than those of wild type (WT) plants. Compared to WT plants, transgenic tobacco plants accumulated more Na+ and K+ and maintained higher K+/Na+ ratios in tissues by salt stress, accompanied by the reduction of chlorophyll loss and lipid peroxidation in the presence of salt. Interestingly, we found that transgenic tobacco plants exhibited markedly higher tonoplast H+-ATPase activity relative to WT plants subjected to salt. Overall, overexpression of IlNHX in tobacco could compartmentalize excessive Na+ into vacuoles to keep the cytosolic K+/Na+ balance by enhanced tonoplast proton pumps activity, which would be contributed to maintain K+ and Na+ homeostasis, to improve photosynthesis efficiency and to protect cell membrane integrity under salt stress.

scholarly journals OsNAC45 is Involved in ABA Response and Salt Tolerance in Rice

Rice ◽  
2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiang Zhang ◽  
Yan Long ◽  
Jingjing Huang ◽  
Jixing Xia
Keyword(s):  
Transcription Factors ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Crop Yields ◽  
Plant Stress ◽  
Root Cells ◽  
Nac Transcription Factors ◽  
Rice Plants ◽  
Plant Stress Responses

Abstract Background Salt stress threatens crop yields all over the world. Many NAC transcription factors have been reported to be involved in different abiotic stress responses, but it remains unclear how loss of these transcription factors alters the transcriptomes of plants. Previous reports have demonstrated that overexpression of OsNAC45 enhances salt and drought tolerance in rice, and that OsNAC45 may regulate the expression of two specific genes, OsPM1 and OsLEA3–1. Results Here, we found that ABA repressed, and NaCl promoted, the expression of OsNAC45 in roots. Immunostaining showed that OsNAC45 was localized in all root cells and was mainly expressed in the stele. Loss of OsNAC45 decreased the sensitivity of rice plants to ABA and over-expressing this gene had the opposite effect, which demonstrated that OsNAC45 played an important role during ABA signal responses. Knockout of OsNAC45 also resulted in more ROS accumulation in roots and increased sensitivity of rice to salt stress. Transcriptome sequencing assay found that thousands of genes were differently expressed in OsNAC45-knockout plants. Most of the down-regulated genes participated in plant stress responses. Quantitative real time RT-PCR suggested that seven genes may be regulated by OsNAC45 including OsCYP89G1, OsDREB1F, OsEREBP2, OsERF104, OsPM1, OsSAMDC2, and OsSIK1. Conclusions These results indicate that OsNAC45 plays vital roles in ABA signal responses and salt tolerance in rice. Further characterization of this gene may help us understand ABA signal pathway and breed rice plants that are more tolerant to salt stress.

scholarly journals Potassium depletion increases proton pump (H+-ATPase) activity in intercalated cells of cortical collecting duct

2000 ◽  
Vol 279 (1) ◽  
pp. F195-F202 ◽  
Author(s):  
Randi B. Silver ◽  
Sylvie Breton ◽  
Dennis Brown
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Collecting Duct ◽  
Proton Pumps ◽  
Intercalated Cells ◽  
Cortical Collecting Duct ◽  
Collecting Ducts ◽  
Acid Load ◽  
Collecting Tubules ◽  
Atpase Staining

Intercalated cells (ICs) from kidney collecting ducts contain proton-transporting ATPases (H+-ATPases) whose plasma membrane expression is regulated under a variety of conditions. It has been shown that net proton secretion occurs in the distal nephron from chronically K+-depleted rats and that upregulation of tubular H+- ATPase is involved in this process. However, regulation of this protein at the level of individual cells has not so far been examined. In the present study, H+-ATPase activity was determined in individually identified ICs from control and chronically K+-depleted rats (9–14 days on a low-K+ diet) by monitoring K+- and Na+-independent H+ extrusion rates after an acute acid load. Split-open rat cortical collecting tubules were loaded with the intracellular pH (pHi) indicator 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, and pHiwas determined by using ratiometric fluorescence imaging. The rate of pHi recovery in ICs in response to an acute acid load, a measure of plasma membrane H+-ATPase activity, was increased after K+ depletion to almost three times that of controls. Furthermore, the lag time before the start of pHirecovery after the cells were maximally acidified fell from 93.5 ± 13.7 s in controls to 24.5 ± 2.1 s in K+-depleted rats. In all ICs tested, Na+- and K+-independent pHi recovery was abolished in the presence of bafilomycin (100 nM), an inhibitor of the H+-ATPase. Analysis of the cell-to-cell variability in the rate of pHi recovery reveals a change in the distribution of membrane-bound proton pumps in the IC population of cortical collecting duct from K+-depleted rats. Immunocytochemical analysis of collecting ducts from control and K+-depleted rats showed that K+-depletion increased the number of ICs with tight apical H+ATPase staining and decreased the number of cells with diffuse or basolateral H+-ATPase staining. Taken together, these data indicate that chronic K+ depletion induces a marked increase in plasma membrane H+ATPase activity in individual ICs.

scholarly journals Thiourea and hydrogen peroxide priming improved K+ retention and source-sink relationship for mitigating salt stress in rice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manish Pandey ◽  
Radha Krishna Paladi ◽  
Ashish Kumar Srivastava ◽  
Penna Suprasanna
Keyword(s):  
Hydrogen Peroxide ◽  
Salt Stress ◽  
Rice Variety ◽  
Nacl Stress ◽  
Stress Conditions ◽  
Field Conditions ◽  
Growth And Yield ◽  
Yield Attributes ◽  
Redox Environment ◽  
Source Sink

AbstractPlant bioregulators (PBRs) represent low-cost chemicals for boosting plant defense, especially under stress conditions. In the present study, redox based PBRs such as thiourea (TU; a non-physiological thiol-based ROS scavenger) and hydrogen peroxide (H2O2; a prevalent biological ROS) were assessed for their ability to mitigate NaCl stress in rice variety IR 64. Despite their contrasting redox chemistry, TU or H2O2 supplementation under NaCl [NaCl + TU (NT) or NaCl + H2O2 (NH)] generated a reducing redox environment in planta, which improved the plant growth compared with those of NaCl alone treatment. This was concomitant with better K+ retention and upregulated expression of NaCl defense related genes including HAK21, LEA1, TSPO and EN20 in both NT and NH treated seedlings. Under field conditions, foliar applications of TU and H2O2, at vegetative growth, pre-flowering and grain filling stages, increased growth and yield attributes under both control and NaCl stress conditions. Principal component analysis revealed glutathione reductase dependent reduced ROS accumulation in source (flag leaves) and sucrose synthase mediated sucrose catabolism in sink (developing inflorescence), as the key variables associated with NT and NH mediated effects, respectively. In addition, photosystem-II efficiency, K+ retention and source-sink relationship were also improved in TU and H2O2 treated plants. Taken together, our study highlights that reducing redox environment acts as a central regulator of plant’s tolerance responses to salt stress. In addition, TU and H2O2 are proposed as potential redox-based PBRs for boosting rice productivity under the realistic field conditions.

scholarly journals The efficacy of different seed priming agents for promoting sorghum germination under salt stress

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245505
Author(s):  
Xiaofei Chen ◽  
Ruidong Zhang ◽  
Yifan Xing ◽  
Bing Jiang ◽  
Bang Li ◽  
...  
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Germination Rate ◽  
Principal Component ◽  
Dry Weight ◽  
Seed Priming ◽  
Nacl Stress ◽  
Future Research ◽  
Fresh Weight ◽  
Positive Effects

Sorghum [Sorghum bicolor (L.) Moench] seed germination is sensitive to salinity, and seed priming is an effective method for alleviating the negative effects of salt stress on seed germination. However, few studies have compared the effects of different priming agents on sorghum germination under salt stress. In this study, we quantified the effects of priming with distilled water (HP), sodium chloride (NaCl), potassium chloride (KCl), calcium chloride (CaCl2), and polyethylene glycol (PEG) on sorghum seed germination under 150 mM NaCl stress. The germination potential, germination rate, germination index, vigor index, root length, shoot length, root fresh weight, shoot fresh weight, root dry weight, and shoot dry weight were significantly reduced by salt stress. Different priming treatments alleviated the germination inhibition caused by salt stress to varying degrees, and 50 mM CaCl2 was the most effective treatment. In addition, the mitigation effect of priming was stronger on root traits than on shoot traits. Mitigation efficacy was closely related to both the type of agent and the concentration of the solution. Principal component analysis showed that all concentrations of CaCl2 had higher scores and were clearly distinguished from other treatments based on their positive effects on all germination traits. The effects of the other agents varied with concentration. The priming treatments were divided into three categories based on their priming efficacy, and the 50, 100, and 150 mM CaCl2 treatments were placed in the first category. The 150 mM KCl, 10% PEG, HP, 150 mM NaCl, 30% PEG, and 50 mM KCl treatments were placed in the second category, and the 100 mM NaCl, 100 mM KCl, 20% PEG, and 50 mM NaCl treatments were least effective and were placed in the third category. Choosing appropriate priming agents and methods for future research and applications can ensure that crop seeds germinate healthily under saline conditions.

Differential regulation of H+-ATPases in MDCK-C11 cells by aldosterone and vasopressin

2009 ◽  
Vol 87 (9) ◽  
pp. 653-665 ◽  
Author(s):  
Priscilla M.C. Dos Santos ◽  
Fabio P. Freitas ◽  
Jeane Mendes ◽  
Ana Lucia Tararthuch ◽  
Ricardo Fernandez
Keyword(s):  
Atpase Activity ◽  
Mdck Cells ◽  
Collecting Duct ◽  
Colorimetric Method ◽  
Proton Pumps ◽  
Ph Optimum ◽  
Cell Monolayers ◽  
Dose Dependent Fashion ◽  
Specific Antagonist ◽  
Dose Dependent

The objective of the present work was to characterize the biochemical activity of the proton pumps present in the C11 clone of Madin–Darby canine kidney (MDCK) cells, akin to intercalated cells of the collecting duct, as well as to study their regulation by hormones like aldosterone and vasopressin. MDCK-C11 cells from passages 78 to 86 were utilized. The reaction to determine H+-ATPase activity was started by addition of cell homogenates to tubes contained the assay medium. The inorganic phosphate (Pi) released was determined by a colorimetric method modified from that described by Fiske and Subbarow. Changes in intracellular calcium concentration in the cells was determined using the Ca2+-sensing dye fluo-4 AM. Homogenates of MDCK-C11 cells present a bafilomycin-sensitive activity (vacuolar H+-ATPase), and a vanadate-sensitive activity (H+/K+-ATPase). The bafilomycin-sensitive activity showed a pH optimum of 6.12. ATPase activity was also stimulated in a dose-dependent fashion as K+ concentration was increased between 0 and 50 mmol·L–1, with an apparent Km for the release of Pi of 0.13 mmol·L–1 and Vmax of 22.01 nmol·mg–1·min–1. Incubation of cell monolayers with 10−8 mol·L–1 aldosterone for 24 h significantly increased vacuolar H+-ATPase activity, an effect prevented by 10−5 mol·L–1 spironolactone. Vacuolar H+-ATPase activity was also stimulated by 10−11 mol·L–1 vasopressin, an effect prevented by a V1 receptor-specific antagonist. This dose of vasopressin determined a sustained rise of cytosolic ionized calcium. We conclude that (i) homogenates of MDCK-C11 cells present a bafilomycin-sensitive (H+-ATPase) activity and a vanadate-sensitive (H+/K+-ATPase) activity, and (ii) vacuolar H+-ATPase activity is activated by aldosterone through a genomic pathway and by vasopressin through V1 receptors.

Global identification of miRNAs and targets in Populus euphratica under salt stress

2013 ◽  
Vol 81 (6) ◽  
pp. 525-539 ◽  
Author(s):  
Bosheng Li ◽  
Hui Duan ◽  
Jigang Li ◽  
Xing Wang Deng ◽  
Weilun Yin ◽  
...  
Keyword(s):  
Salt Stress ◽  
Populus Euphratica ◽  
Global Identification
Sign in / Sign up

Export Citation Format

Share Document