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![Possible working model demonstrating the Ca⁺²-mediated synchronization of PM H⁺-ATPase and NADPH oxidase in Vigna radiata (L.) Wilczek root. PM NADPH oxidase (RBOH) mediated O2˙ˉ production is one of the prerequisites for cell elongation growth through wall relaxation. H2O2, being produced spontaneously or through SOD, either gets converted to ˙OH radical and cleave wall polysaccharides or crosses the PM through aquaporins and serves as signaling molecule, Ca⁺² channel activator, PM H⁺-ATPase inducer (at low concentration), etc. The membrane depolarization resulting from the transfer of electron by NOX is stabilized by protons extruded out by PM H⁺-ATPase, which simultaneously provides substrate (protons) for SOD. PM H⁺-ATPase induced membrane hyperpolarization, besides being promontory for expansins and certain wall relaxation-related enzymes, activates HACC which, together with other H2O2 stimulated Ca⁺² channels, builds up [Ca⁺²]cyt through cross-PM Ca⁺² influx. By binding with EF hand motif Ca⁺² activates NOX whereas it modulates H⁺-ATPase activity by phosphorylation at different sites. La⁺³, a Ca⁺² channel blocker and EGTA, a Ca⁺² chelator inhibits the formation of [Ca⁺²]cyt and repress both NOX and PM H⁺-ATPase activity. The inhibition of both NOX and PM H⁺-ATPase by sodium ortho-vanadate (PM H⁺-ATPase inhibitor), CCCP (protonophore), CuCl2 (O2˙ˉ scavenger), KI (H2O2 scavenger), and ZnCl2 (NOX inhibitor) treatments indicates towards a Ca⁺²-intervened functional harmony between the two enzymes](publication/323125053/figure/fig4/AS:960323481776142@1605970368117/Possible-working-model-demonstrating-the-Ca-mediated-synchronization-of-PM-H-ATPase.gif)
Possible working model demonstrating the Ca⁺²-mediated synchronization of PM H⁺-ATPase and NADPH oxidase in Vigna radiata (L.) Wilczek root. PM NADPH oxidase (RBOH) mediated O2˙ˉ production is one of the prerequisites for cell elongation growth through wall relaxation. H2O2, being produced spontaneously or through SOD, either gets converted to ˙OH radical and cleave wall polysaccharides or crosses the PM through aquaporins and serves as signaling molecule, Ca⁺² channel activator, PM H⁺-ATPase inducer (at low concentration), etc. The membrane depolarization resulting from the transfer of electron by NOX is stabilized by protons extruded out by PM H⁺-ATPase, which simultaneously provides substrate (protons) for SOD. PM H⁺-ATPase induced membrane hyperpolarization, besides being promontory for expansins and certain wall relaxation-related enzymes, activates HACC which, together with other H2O2 stimulated Ca⁺² channels, builds up [Ca⁺²]cyt through cross-PM Ca⁺² influx. By binding with EF hand motif Ca⁺² activates NOX whereas it modulates H⁺-ATPase activity by phosphorylation at different sites. La⁺³, a Ca⁺² channel blocker and EGTA, a Ca⁺² chelator inhibits the formation of [Ca⁺²]cyt and repress both NOX and PM H⁺-ATPase activity. The inhibition of both NOX and PM H⁺-ATPase by sodium ortho-vanadate (PM H⁺-ATPase inhibitor), CCCP (protonophore), CuCl2 (O2˙ˉ scavenger), KI (H2O2 scavenger), and ZnCl2 (NOX inhibitor) treatments indicates towards a Ca⁺²-intervened functional harmony between the two enzymes
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Plasma membrane (PM) H+-ATPase and NADPH oxidase (NOX) are two key enzymes responsible for cell wall relaxation during elongation growth through apoplastic acidification and production of ˙OH radical via O2˙−, respectively. Our experiments revealed a putative feed-forward loop between these enzymes in growing roots of Vigna radiata (L.) Wilczek see...
Citations
... Decreased expression of the OsNADH-GOGAT and OsFd-GOGAT genes may reinforce an action at this point, where there is an initial uptake of N-NO 3 or N-NH 4 + , since these genes are responsive to the assimilation of N-NO 3 and N-NH 4 + ). Although the literature relates the expression of NOX genes to physiological stress conditions in plants (Chang et al. 2016), a direct relationship between NOXs/RBOHs and H + -ATPases reveals an important role in the development of lateral roots (Majumdar and Kar 2018;Hu et al. 2020). Although there was no visual evidence of damage to plant growth and development following the treatments in this study, the leaves showed increased expression of OsNOX9 after both foliar and root treatment because these proteins Content courtesy of Springer Nature, terms of use apply. ...
The red alga Kappaphycus alvarezii (Rhodophyta) is one of the most cultivated species in the world. Extracts obtained from Kappaphycus (KAlv-sap) have been shown to promote plant growth as well as defense against abiotic stresses. The present study aimed to examine the regulation of photosynthesis and the genetic and metabolic mechanisms resulting from foliar and root application of KAlv-sap in rice plants (Oryza sativa). KAlv-sap was obtained from fresh algae cultivated in the bay of Ilha Grande, Paraty, Brazil, and previously well characterized. Experiments were performed using applications at 21 and 24 days after germination (DAG) with four treatments: control (without KAlv-sap); two foliar application treatments with 2% and 10% KAlv-sap (2% K-sapF and 10% KAlv-sapF, respectively); and root application treatment with 2% KAlv-sap (2% KAlv-sapR). Both foliar and root applications of KAlv-sap promoted improved photosynthetic efficiency transport and adaptive response to the stress, at least until 27 DAG. KAlv-sap application increased the uptake of N and K, leading to an increase in N-NO3⁻ and amino-N. Such conditions promote increases in biomass production, growth, and root development. Root application of KAlv-sap stimulated the growth of plants at later times compared to foliar application and, in both cases, the pathways of action include the regulation of redox homeostasis. The results shed light on the pathways of action stimulated by aqueous extracts of Kappaphycus, contributing to the improvement of the agricultural bioinputs.
... The enzymatic performance of the PM H + -ATPase (EC 3.6.1.35) was evaluated, as ascertained by the Hejl and Koster (2004) technique and explained by Majumdar and Kar (2018), was evaluated. The enzyme's activity was determined by measuring the production of inorganic phosphate at a wavelength of 700 nm. ...
... On the other hand, ˙OH is the most reactive member of ROS family and it cleaves wall polysaccharides thereby facilitating site-specific cell wall relaxation and enhancement of plastic extensibility (Schopfer 2001;Liszkay et al. 2004;Halliwell and Gutteridge 2015;Airianah et al. 2016). Interestingly, functional synchronization of PM H + -ATPase and NOXled apoplastic ROS cascade along with a potent transcriptional co-regulation of PM H + -ATPase and NOX has been identified recently in connection with early root growth in Vigna radiata (Majumdar and Kar 2018. ...
... Apoplastic superoxide was estimated by XTT reduction assay following Liszkay et al. (2004) and Majumdar and Kar (2018). Roots (300 mg, in triplicates), excised from seedlings treated with different agents and control sets, were immersed in 1 mL potassium-phosphate buffer (20 mM, pH 6.0) containing XTT (final concentration 500 µM). ...
... Spectrophotometric assay of NOX activity was carried out following Frahry and Schopfer (2001) and Majumdar and Kar (2018) with modifications. Root tissue (300 mg) was homogenized in extraction medium comprising of sodiumphosphate buffer (50 mM, pH 6.8) with 0.5% Triton X-100 and the homogenate was subjected to centrifugation at 10,000 rpm for 15 min at 4ºC. ...
Plasma membrane located NADPH oxidase (NOX) and H⁺-ATPase function cooperatively during early root growth to maintain the membrane electrical balance while mediating cell growth through wall relaxation. A potent transcriptional co-regulation of the two enzymes has also been identified which further highlights the essentiality of NOX-PM H⁺-ATPase feed-forward loop, mediated by H2O2 and Ca+ 2, during root growth. The pathway from superoxide (O2˙ˉ) generation to cell elongation involves intermediary conversion of O2˙ˉ to H2O2 by superoxide dismutase (SOD) and subsequently by class III peroxidase (Prx) to produce ˙OH radical, necessary for wall polysaccharide cleavage. Present work demonstrates further the involvement of polyamine metabolism in the ROS-mediated process of root growth regulation. Thus, in addition to retardation of root growth, inhibition of PAO (polyamine oxidase) results in significant diminution of NOX and PM H⁺-ATPase activities. On the other hand, exogenous application of PAs (viz. putrescine, spermidine and spermine) stimulates the NOX-PM H⁺-ATPase cascade resulting in augmented production of O2˙ˉ and H2O2. Interestingly, blocking of NOX and PM H⁺-ATPase activities (through specific inhibitors) as well as quenching of their products (through dedicated antagonistic agents) drastically reduced PAO activity as observed in both spectrophotometric and native PAGE assays. Inhibition of PAO has also been recorded when treated with Ca+ 2-chelator and Ca+ 2-channel blocker. Correlating the present observations with earlier findings it has been hypothesized that H2O2 and Ca+ 2 are serving as mediators of interplay between NOX-PM H⁺-ATPase cascade and PA metabolism during early root growth in Vigna radiata (L.) Wilczek seedlings.
... The method of Hejl and Koster (2004), as described by Majumdar and Kar (2018), was used to measure the activity of plasma membrane H + -ATPase (PM H + -ATPase). The production of inorganic phosphate at 700 nm was used to assess the enzyme's activity. ...
Crop plants face severe yield losses worldwide owing to their exposure to multiple abiotic stresses. The study described here, was conducted to comprehend the response of cucumber seedlings to drought (induced by 15% w/v polyethylene glycol 8000; PEG) and nickel (Ni) stress in presence or absence of titanium dioxide nanoparticle (nTiO2). In addition, it was also investigated how nitrogen (N) and carbohydrate metabolism, as well as the defense system, are affected by endogenous potassium (K+) and hydrogen sulfide (H2S). Cucumber seedlings were subjected to Ni stress and drought, which led to oxidative stress and triggered the defense system. Under the stress, N and carbohydrate metabolism were differentially affected. Supplementation of the stressed seedlings with nTiO2 (15 mg L-1) enhanced the activity of antioxidant enzymes, ascorbate-glutathione (AsA-GSH) system and elevated N and carbohydrates metabolism. Application of nTiO2 also enhanced the accumulation of phytochelatins and activity of the enzymes of glyoxalase system that provided additional protection against the metal and toxic methylglyoxal. Osmotic stress brought on by PEG and Ni, was countered by the increase of proline and carbohydrates levels, which helped the seedlings keep their optimal level of hydration. Application nTiO2 improved the biosynthesis of H2S and K+ retention through regulating Cys biosynthesis and H+-ATPase activity, respectively. Observed outcomes lead to the conclusion that nTiO2 maintains redox homeostasis, and normal functioning of N and carbohydrates metabolism that resulted in the protection of cucumber seedlings against drought and Ni stress. Use of 20 mM tetraethylammonium chloride (K+- channel blocker), 500 μM sodium orthovanadate (PM H+-ATPase inhibitor), and 1 mM hypotaurine (H2S scavenger) demonstrate that endogenous K+ and H2S were crucial for the nTiO2-induced modulation of plants' adaptive responses to the imposed stress.
... The methodology of Hejl and Koster (2004) was slightly modified to measure plasma membrane H + -ATPase (PM H + -ATPase) activity (Majumdar and Kar, 2018). At the wavelength of 700 nm, the synthesis of inorganic phosphate was measured, and the enzyme's activity was identified. ...
Contamination of soils with chromium (Cr) jeopardized agriculture production globally. The current study was planned with the aim to better comprehend how melatonin (Mel) and hydrogen sulfide (H2S) regulate antioxidant defense system, potassium (K) homeostasis, and nitrogen (N) metabolism in tomato seedlings under Cr toxicity. The data reveal that application of 30 μM Mel to the seedlings treated with 25 μM Cr has a positive effect on H2S metabolism that resulted in a considerable increase in H2S. Exogenous Mel improved phytochelatins content and H+-ATPase activity with an associated increase in K content as well. Use of tetraethylammonium chloride (K+-channel blocker) and sodium orthovanadate (H+-ATPase inhibitor) showed that Mel maintained K homeostasis through regulating H+-ATPase activity under Cr toxicity. Supplementation of the stressed seedlings with Mel substantially scavenged excess ROS that maintained ROS homeostasis. Reduced electrolyte leakage and lipid peroxidation were additional signs of Mel's ROS scavenging effects. In addition, Mel also maintained normal functioning of nitrogen (N) metabolism and ascorbate-glutathione (AsA-GSH) system. Improved level of N fulfilled its requirement for various enzymes that have induced resilience during Cr stress. Additionally, the AsA-GSH cycle's proper operation maintained redox equilibrium, which is necessary for the biological system to function normally. Conversely, 1 mM hypotaurine (H2S scavenger) abolished the Mel-effect and again Cr-induced impairment on the above-mentioned parameters was observed even in presence of Mel. Therefore, based on the observed findings, we concluded that Mel needs endogenous H2S to alleviate Cr-induced impairments in tomato seedlings.
... Lots of studies have addressed that the roles of CDPKs in plant growth regulation and various stress responses are closely associated with NOX-/RBOH mediated ROS production in a Ca 2+ -dependent manner (Potockýet al., 2007;Potockýet al., 2012;Boisson-Dernier et al., 2013;Yamauchi et al., 2017). In addition, numerous literatures confirmed that CDPKs can directly interact with NOXs/RBOHs, and both of which synergistically involved in plant development and response to environmental stress (Kobayashi et al., 2007;Dubiella et al., 2013;Majumdar and Kar, 2018). Therefore, in order to obtain more insights into the function of TaCDPKs, the network signal relationships between 26 members of CDPK family and 9 members of NOX family from the network of STRING had been obtained and drawn with the software of Cytoscape and Adobe Photoshop (Figure 3). ...
As the critical sensors and decoders of calcium signal, calcium-dependent protein kinase (CDPK) has become the focus of current research, especially in plants. However, few resources are available on the properties and functions of CDPK gene family in Triticum aestivum (TaCDPK). Here, a total of 79 CDPK genes were identified in the wheat genome. These TaCDPKs could be classified into four subgroups on phylogenesis, while they may be classified into two subgroups based on their tissue and organ-spatiotemporal expression profiles or three subgroups according to their induced expression patterns. The analysis on the signal network relationships and interactions of TaCDPKs and NADPH (reduced nicotinamide adenine dinucleotide phosphate oxidases, NOXs), the key producers for reactive oxygen species (ROS), showed that there are complicated cross-talks between these two family proteins. Further experiments demonstrate that, two members of TaCDPKs, TaCDPK2/4, can interact with TaNOX7, an important member of wheat NOXs, and enhanced the TaNOX7-mediated ROS production. All the results suggest that TaCDPKs are highly expressed in wheat with distinct tissue or organ-specificity and stress-inducible diversity, and play vital roles in plant development and response to biotic and abiotic stresses by directly interacting with TaNOXs for ROS production.
... After binding to 14-3-3 proteins (Figure 10,③), FCA triggers extracellular acidification via binding to PM ATPases in a few minutes (Kinoshita & Shimazaki, 2001; Figure 10,④), which could trigger cell wall loosening enzymes supporting cell-wall degradation (Kesten et al., 2019). The acidification will also activate RbOH (Huang et al., 2014;Majumdar & Kar, 2018) after 10 min reaching the peak after 60 min (Figure 10,⑤). ...
Apoplectic breakdown from Grapevines Trunk Diseases (GTDs) has become a serious challenge to viticulture in consequence to drought stress. We hypothesise that fungal aggressiveness is controlled by a chemical communication between host and colonising fungus. We introduce the new concept of a “plant surrender signal” accumulating in host plants under stress and facilitating the aggressive behaviour of the strain Neofusicoccum parvum (Bt‐67) causing Botryosphaeriaceae‐related dieback in grapevines. Using a cell‐based experimental system (Vitis cells) and bioactivity‐guided fractionation, we identify trans‐ferulic acid, a monolignol precursor, as “surrender signal”. We show that this signal specifically activates secretion of the fungal phytotoxin Fusicoccin A aglycone. We show further that this phytotoxin, mediated by 14‐3‐3 proteins, activates programmed cell death in Vitis cells. We arrive at a model showing a chemical communication facilitating fusicoccin A secretion that drives necrotrophic behaviour during Botryosphaeriaceae‐Vitis interaction through trans‐ferulic acid. We thus hypothesise that a channeling of the phenylpropanoid pathway from this lignin precursor to the trans‐resveratrol phytoalexin could be a target for future therapy. This article is protected by copyright. All rights reserved.
... In addition, Köster et al. indicated that Ca 2+ signaling was central to both pattern-and effector-triggered immunity activation of the immune system in plants [142]. Furthermore, the calcium-dependent protein kinase TaCDPK can directly interact with NOXs/RBOHs in a Ca 2+ -dependent manner [139,145,146], both of which are synergistically involved in plant defense responses to pathogens [147][148][149][150]. Therefore, under pathogen stimulation, plant cells often elevate the levels of ROS to implement plant immunity by eliminating compromised host cells, in turn limiting the further infection by the pathogen. ...
Fusarium head blight (FHB), or scab, caused by Fusarium species, is an extremely destructive fungal disease in wheat worldwide. In recent decades, researchers have made unremitting efforts in genetic breeding and control technology related to FHB and have made great progress, especially in the exploration of germplasm resources resistant to FHB; identification and pathogenesis of pathogenic strains; discovery and identification of disease-resistant genes; biochemical control, and so on. However, FHB burst have not been effectively controlled and thereby pose increasingly severe threats to wheat productivity. This review focuses on recent advances in pathogenesis, resistance quantitative trait loci (QTLs)/genes, resistance mechanism, and signaling pathways. We identify two primary pathogenetic patterns of Fusarium species and three significant signaling pathways mediated by UGT, WRKY, and SnRK1, respectively; many publicly approved superstar QTLs and genes are fully summarized to illustrate the pathogenetic patterns of Fusarium species, signaling behavior of the major genes, and their sophisticated and dexterous crosstalk. Besides the research status of FHB resistance, breeding bottlenecks in resistant germplasm resources are also analyzed deeply. Finally, this review proposes that the maintenance of intracellular ROS (reactive oxygen species) homeostasis, regulated by several TaCERK-mediated theoretical patterns, may play an important role in plant response to FHB and puts forward some suggestions on resistant QTL/gene mining and molecular breeding in order to provide a valuable reference to contain FHB outbreaks in agricultural production and promote the sustainable development of green agriculture.
... To further validate the involvement of AHA5 in H 2 O 2 production, the H 2 O 2 burst assay was carried out with the H + -ATPase inhibitor sodium vanadate. With sodium vanadate (VO4) treatment, H + -ATPase activities (H + out-pumping activities) were suppressed, and the PAMP-induced H 2 O 2 production could be reduced [40][41][42]. As expected, the PAMP-flg22-induced H 2 O 2 production was sharply reduced in WT Col-0 leaf samples with VO4 treatment, which confirmed that the H + -ATPase activities (H + out-pumping activities) are involved in H 2 O 2 production (Figure 3c,d). ...
Plants evolve a prompt and robust immune system to defend themselves against pathogen infections. Pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) is the first battle layer activated upon the PAMP’s perception, which leads to multiple defense responses. The plasma membrane (PM) H+-ATPases are the primary ion pumps to create and maintain the cellular membrane potential that is critical for various essential biological processes, including plant growth, development, and defense. This study discovered that the PM H+-ATPase AHA5 is negatively involved in Arabidopsis PTI against the virulent pathogen Pseudomonas syringae pvr. tomato (Pto) DC3000 infection. The aha5 mutant plants caused the reduced stomata opening upon the Pto infection, which was associated with the salicylic acid (SA) pathway. In addition, the aha5 mutant plants caused the increased levels of callose deposition, defense-related gene expression, and SA accumulation. Our results also indicate that the PM H+-ATPase activity of AHA5 probably mediates the coupling of H2O2 generation and the apoplast alkalization in PTI responses. Moreover, AHA5 was found to interact with a vital defense regulator, RPM1-interacting protein 4 (RIN4), in vitro and in vivo, which might also be critical for its function in PTI. In summary, our studies show that AHA5 functions as a novel and critical component that is negatively involved in PTI by coordinating different defense responses during the Arabidopsis–Pto DC3000 interaction.
... Plasma membrane H + -ATPase (PM H + -ATPase) activity was measured in fresh leaves of faba bean seedlings following the protocol of Hejl and Koster (2004) with minor changes (Majumdar and Kar, 2018). The PM H + -ATPase activity was gauged by quantifying the release of inorganic phosphate (Pi) at the absorbance of 700 nm. ...
Hydrogen sulfide (H2S) has emerged as a potential gasotransmitter in plants with beneficial role in stress amelioration. Despite the various known functions of H2S in plants, not much information is available to explain the associative role of molybdenum (Mo) and hydrogen sulfide (H2S) signaling in plants under arsenic toxicity. In view to address such lacunae in our understanding of the integrative roles of these biomolecules, the present work attempts to decipher the roles of Mo and H2S in mitigation of arsenate (AsV) toxicity in faba bean (Vicia faba L.) seedlings. AsV-stressed seedlings supplemented with exogenous Mo and/or NaHS treatments (H2S donor) showed resilience to AsV toxicity manifested by reduction of apoptosis, reactive oxygen species (ROS) content, down-regulation of NADPH oxidase and GOase activity followed by upregulation of antioxidative enzymes in leaves. Fluorescent localization of ROS in roots reveals changes in its intensity and spatial distribution in response to MO and NaHS supplementation during AsV stress. Under AsV toxicity conditions, seedlings subjected to Mo + NaHS showed an increased rate of nitrogen metabolism evident by elevation in nitrate reductase, nitrite reductase and glutamine synthetase activity. Furthermore, the application of Mo and NaHS in combination positively upregulates cysteine and hydrogen sulfide biosynthesis in the absence and presence of AsV stress. Mo plus NaHS-supplemented seedlings exposed to AsV toxicity showed a substantial reduction in oxidative stress manifested by reduced ELKG, lowered MDA content and higher accumulation proline in leaves. Taken together, the present findings provide substantial evidence on the synergetic role of Mo and H2S in mitigating AsV stress in faba bean seedlings. Thus, the application of Mo and NaHS reveal their agronomic importance to encounter heavy metal stress for management of various food crops.
