Peroxidase activity against guaiacol, NADH, chlorogenic acid, ferulic acid and coniferyl alcohol in root tips of Lotus japonicus and L. corniculatus grown under low pH and aluminium stress

AbstractThe purpose of this study was to examine the impact of low pH and Al stress on the apoplastic production of H2O2 and POD activity against guaiacol, ferulic acid, coniferyl alcohol, NADH and chlorogenic acid in the root tip (RT) of two cultivars of Lotus corniculatus and the model Lotus japonicus Gifu, with the goal to determine the possible role of POD activity in proton and Al tolerance. Our results suggest that Lotus corniculatus cv. UFRGS is more tolerant to low pH and Al than cv. Draco due to the high POD activities involved in CW strengthening. The enzymatic response of Lotus japonicus Gifu is similar rather to the sensitive cultivar. On the other hand, in cvs Draco and Gifu low pH induced the activation of CW-modifying PODs, which is probably a component of the defence response of roots to the presence of toxic protons. Aluminium did not activate further these activities suggesting that defence response and acclimation to low pH confers also effective defence against Al toxicity in Lotus species. The activity of NADH-POD and CGA-POD were not affected significantly by exposure to low pH or Al. Al and pH induced drop in H2O2 production, which was more relevant in cv. Gifu and Draco than in cv. UFRGS is probably associated with enhanced activity of peroxidases involved in secondary CW metabolism utilizing H2O2 as an electron acceptor.

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Method development for the determination of textural properties of sugar beet roots

Sugar Industry ◽

10.36961/si23306 ◽

2019 ◽

pp. 392-400 ◽

Cited By ~ 2

Author(s):

Gunnar Kleuker ◽

Christa M. Hoffmann

Keyword(s):

Sugar Beet ◽

Compression Test ◽

Storage Period ◽

Textural Properties ◽

Small Sample ◽

Root Tip ◽

Flexural Test ◽

Sample Distribution ◽

The Impact

The harvest of sugar beet leads to root tip breakage and surface damage through mechanical impacts, which increase storage losses. For the determination of textural properties of sugar beet roots with a texture analyzer a reliable method description is missing. This study aimed to evaluate the impact of washing, soil tare, storage period from washing until measurement, sample distribution and number of roots on puncture and compression measurements. For this purpose, in 2017 comprehensive tests were conducted with sugar beet roots grown in a greenhouse. In a second step these tests were carried out with different Beta varieties from a field trial, and in addition, a flexural test was included. Results show that the storage period after washing and the sample distribution had an influence on the puncture and compression strength. It is suggested to wash the roots by hand before the measurement and to determine the strength no later than 48 h after washing. For reliable and comparable results a radial distribution of measurement points around the widest circumference of the root is recommended for the puncture test. The sample position of the compression test had an influence on the compressive strength and therefore, needs to be clearly defined. For the puncture and the compression test it was possible to achieve stable results with a small sample size, but with increasing heterogeneity of the plant stand a higher number of roots is required. The flexural test showed a high variability and is, therefore, not recommended for the analysis of sugar beet textural properties.

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The Arabidopsis Root Tip (Phospho)Proteomes at Growth-Promoting versus Growth-Repressing Conditions Reveal Novel Root Growth Regulators

Cells ◽

10.3390/cells10071665 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1665

Author(s):

Natalia Nikonorova ◽

Evan Murphy ◽

Cassio Flavio Fonseca de Lima ◽

Shanshuo Zhu ◽

Brigitte van de Cotte ◽

...

Keyword(s):

Cell Wall ◽

Root Growth ◽

Growth Regulators ◽

Growth Regulation ◽

Phosphorylation Site ◽

Primary Root ◽

Root Tip ◽

Arabidopsis Root ◽

Growth Promoting ◽

The Impact

Auxin plays a dual role in growth regulation and, depending on the tissue and concentration of the hormone, it can either promote or inhibit division and expansion processes in plants. Recent studies have revealed that, beyond transcriptional reprogramming, alternative auxin-controlled mechanisms regulate root growth. Here, we explored the impact of different concentrations of the synthetic auxin NAA that establish growth-promoting and -repressing conditions on the root tip proteome and phosphoproteome, generating a unique resource. From the phosphoproteome data, we pinpointed (novel) growth regulators, such as the RALF34-THE1 module. Our results, together with previously published studies, suggest that auxin, H+-ATPases, cell wall modifications and cell wall sensing receptor-like kinases are tightly embedded in a pathway regulating cell elongation. Furthermore, our study assigned a novel role to MKK2 as a regulator of primary root growth and a (potential) regulator of auxin biosynthesis and signalling, and suggests the importance of the MKK2 Thr31 phosphorylation site for growth regulation in the Arabidopsis root tip.

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Impact of the acidic environment on gene expression and functional parameters of tumors in vitro and in vivo

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-020-01815-4 ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Mandy Rauschner ◽

Luisa Lange ◽

Thea Hüsing ◽

Sarah Reime ◽

Alexander Nolze ◽

...

Keyword(s):

Gene Expression ◽

Cell Death ◽

Western Blot ◽

Tumor Cell ◽

Low Ph ◽

Strong Increase ◽

Acidic Ph ◽

The Impact

Abstract Background The low extracellular pH (pHe) of tumors resulting from glycolytic metabolism is a stress factor for the cells independent from concomitant hypoxia. The aim of the study was to analyze the impact of acidic pHe on gene expression on mRNA and protein level in two experimental tumor lines in vitro and in vivo and were compared to hypoxic conditions as well as combined acidosis+hypoxia. Methods Gene expression was analyzed in AT1 prostate and Walker-256 mammary carcinoma of the rat by Next Generation Sequencing (NGS), qPCR and Western blot. In addition, the impact of acidosis on tumor cell migration, adhesion, proliferation, cell death and mitochondrial activity was analyzed. Results NGS analyses revealed that 147 genes were uniformly regulated in both cell lines (in vitro) and 79 genes in both experimental tumors after 24 h at low pH. A subset of 25 genes was re-evaluated by qPCR and Western blot. Low pH consistently upregulated Aox1, Gls2, Gstp1, Ikbke, Per3, Pink1, Tlr5, Txnip, Ypel3 or downregulated Acat2, Brip1, Clspn, Dnajc25, Ercc6l, Mmd, Rif1, Zmpste24 whereas hypoxia alone led to a downregulation of most of the genes. Direct incubation at low pH reduced tumor cell adhesion whereas acidic pre-incubation increased the adhesive potential. In both tumor lines acidosis induced a G1-arrest (in vivo) of the cell cycle and a strong increase in necrotic cell death (but not in apoptosis). The mitochondrial O2 consumption increased gradually with decreasing pH. Conclusions These data show that acidic pHe in tumors plays an important role for gene expression independently from hypoxia. In parallel, acidosis modulates functional properties of tumors relevant for their malignant potential and which might be the result of pH-dependent gene expression.

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Induction of Tetraploid Lotus japonicus and Interspecific Hybridization with Super-Root-Derived Lotus corniculatus Regenerants

Crop Science ◽

10.2135/cropsci2016.09.0743 ◽

2017 ◽

Vol 57 (5) ◽

pp. 2387-2394 ◽

Cited By ~ 1

Author(s):

Masatsugu Hashiguchi ◽

Rinda Puspasari ◽

Yuya Suematsu ◽

Melody Muguerza ◽

Hidenori Tanaka ◽

...

Keyword(s):

Interspecific Hybridization ◽

Lotus Japonicus ◽

Lotus Corniculatus

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Stream plant chemistry as indicator of acid sulphate soils in Sweden

Agricultural and Food Science ◽

10.2137/1459606054224165 ◽

2008 ◽

Vol 14 (1) ◽

pp. 83 ◽

Cited By ~ 6

Author(s):

K. LAX

Keyword(s):

Surface Waters ◽

Stream Water ◽

Low Ph ◽

Fontinalis Antipyretica ◽

Acid Sulphate ◽

Fine Grained ◽

Acid Sulphate Soils ◽

Trace Element Chemistry ◽

Study Results ◽

The Impact

Results from the biogeochemical mapping (roots of aquatic plants and Fontinalis antipyretica) conducted by the Geological Survey of Sweden (SGU) reflects the metal load of surface waters draining acid sulphate (AS) soils in Sweden. In this study, results from the biogeochemical, soil geochemical and Quaternary mapping programmes at SGU were used to investigate the impact of fine-grained deposits hosting AS soils on stream water trace element chemistry in two separate areas. In the area around Lake Mälaren, postglacial sediments contain the highest levels of most trace elements studied. Owing to the low pH of AS soils and subsequent leaching, levels of nickel (Ni), cobalt (Co), copper (Cu), sulphur (S), yttrium (Y), uranium (U), tungsten (W), and molybdenum (Mo) were significantly elevated in aquatic roots. Levels were lower in the Skellefteå area, which may be explained by lower concentrations in source deposits. Concentrations of arsenic (As) and lead (Pb) were normal or impoverished in biogeochemical samples from postglacial, finegrained sediment areas. Maps based on ratios (Ni:Pb or Y:Pb) in biogeochemical samples can, together with results from Quaternary mapping, be used to predict areas with AS soils in Sweden.;

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Variation in brachiopod microstructure and isotope geochemistry under low pH–ocean acidification–conditions

10.5194/bg-2018-332 ◽

2018 ◽

Author(s):

Facheng Ye ◽

Hana Jurikova ◽

Lucia Angiolini ◽

Uwe Brand ◽

Gaia Crippa ◽

...

Keyword(s):

Stable Isotope ◽

Ocean Acidification ◽

Isotope Geochemistry ◽

Shell Growth ◽

Low Ph ◽

Secondary Layer ◽

Ph Conditions ◽

One Year ◽

The Impact ◽

Δ13c And Δ18o

Abstract. Throughout the last few decades and in the near future CO2–induced ocean acidification is potentially a big threat to marine calcite-shelled animals (e.g., brachiopods, bivalves, corals and gastropods). Despite the great number of studies focusing on the effects of acidification on shell growth, metabolism, shell dissolution and shell repair, the consequences on biomineral formation remain poorly understood, and only few studies addressed contemporarily the impact of acidification on shell microstructure and geochemistry. In this study, a detailed microstructure and stable isotope geochemistry investigation was performed on nine adult brachiopod specimens of Magellania venosa (Dixon, 1789), grown in the natural environment as well as in controlled culturing experiments at different pH conditions (ranging 7.35 to 8.15 ± 0.05) over different time intervals (214 to 335 days). Details of shell microstructural features, such as thickness of the primary layer, density and size of endopunctae and morphology of the basic structural unit of the secondary layer were analysed using scanning electron microscopy (SEM). Stable isotope compositions (δ13C and δ18O) were tested from the secondary shell layer along shell ontogenetic increments in both dorsal and ventral valves. Based on our comprehensive dataset, we observed that, under low pH conditions, M. venosa produced a more organic-rich shell with higher density of and larger endopunctae, and smaller secondary layer fibres, when subjected to about one year of culturing. Also, increasingly negative δ13C and δ18O values are recorded by the shell produced during culturing and are related to the CO2–source in the culture setup. Both the microstructural changes and the stable isotope results are similar to observations on brachiopods from the fossil record and strongly support the value of brachiopods as robust archives of proxies for studying ocean acidification events in the geologic past.

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Physiological response of root tip of alfalfa to low pH and aluminium stress in water culture

Plant-Soil Interactions at Low pH: Principles and Management ◽

10.1007/978-94-011-0221-6_46 ◽

1995 ◽

pp. 329-331 ◽

Cited By ~ 2

Author(s):

Satoshi Yokota ◽

Kunihiko Ojima

Keyword(s):

Physiological Response ◽

Low Ph ◽

Root Tip ◽

Water Culture

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An Update on Mitochondrial Reactive Oxygen Species Production

Antioxidants ◽

10.3390/antiox9060472 ◽

2020 ◽

Vol 9 (6) ◽

pp. 472 ◽

Cited By ~ 10

Author(s):

Ryan J. Mailloux

Keyword(s):

Mammalian Cells ◽

Protein S ◽

Vital Role ◽

Tissue Type ◽

H2o2 Production ◽

Ros Production ◽

Nutrient Metabolism ◽

Physiological Factors ◽

Genes Encoding ◽

The Impact

Mitochondria are quantifiably the most important sources of superoxide (O2●−) and hydrogen peroxide (H2O2) in mammalian cells. The overproduction of these molecules has been studied mostly in the contexts of the pathogenesis of human diseases and aging. However, controlled bursts in mitochondrial ROS production, most notably H2O2, also plays a vital role in the transmission of cellular information. Striking a balance between utilizing H2O2 in second messaging whilst avoiding its deleterious effects requires the use of sophisticated feedback control and H2O2 degrading mechanisms. Mitochondria are enriched with H2O2 degrading enzymes to desensitize redox signals. These organelles also use a series of negative feedback loops, such as proton leaks or protein S-glutathionylation, to inhibit H2O2 production. Understanding how mitochondria produce ROS is also important for comprehending how these organelles use H2O2 in eustress signaling. Indeed, twelve different enzymes associated with nutrient metabolism and oxidative phosphorylation (OXPHOS) can serve as important ROS sources. This includes several flavoproteins and respiratory complexes I-III. Progress in understanding how mitochondria generate H2O2 for signaling must also account for critical physiological factors that strongly influence ROS production, such as sex differences and genetic variances in genes encoding antioxidants and proteins involved in mitochondrial bioenergetics. In the present review, I provide an updated view on how mitochondria budget cellular H2O2 production. These discussions will focus on the potential addition of two acyl-CoA dehydrogenases to the list of ROS generators and the impact of important phenotypic and physiological factors such as tissue type, mouse strain, and sex on production by these individual sites.

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Cystic Fibrosis-AssociatedStenotrophomonas maltophiliaStrain-Specific Adaptations and Responses to pH

Journal of Bacteriology ◽

10.1128/jb.00478-18 ◽

2019 ◽

Vol 201 (7) ◽

Cited By ~ 2

Author(s):

Tara Gallagher ◽

Joann Phan ◽

Andrew Oliver ◽

Alexander B. Chase ◽

Whitney E. England ◽

...

Keyword(s):

Cystic Fibrosis ◽

Stenotrophomonas Maltophilia ◽

Opportunistic Infections ◽

Expression Profiles ◽

Bacterial Colonization ◽

Low Ph ◽

Lung Damage ◽

Ph Gradients ◽

Content Type ◽

The Impact

ABSTRACTThe airway fluids of cystic fibrosis (CF) patients contain local pH gradients and are more acidic than those of healthy individuals. pH is a critical factor that is often overlooked in studies seeking to recapitulate the infection microenvironment. We sought to determine the impact of pH on the physiology of a ubiqituous yet understudied microbe,Stenotrophomonas maltophilia. Phylogenomics was first used to reconstruct evolutionary relationships between 74 strains ofS. maltophilia(59 from CF patients). Neither the core genome (2,158 genes) nor the accessory genome (11,978 genes) distinguish the CF and non-CF isolates; however, strains from similar isolation sources grouped into the same subclades. We grew two human and six CFS. maltophiliaisolates from different subclades at a range of pH values and observed impaired growth and altered antibiotic tolerances at pH 5. Transcriptomes revealed increased expression of both antibiotic resistance and DNA repair genes in acidic conditions. Although the gene expression profiles ofS. maltophiliain lab cultures and CF sputum were distinct, we found that the same genes associated with low pH were also expressed during infection, and the higher pH cultures were more similar to sputum metatranscriptomes. Our findings suggest thatS. maltophiliais not well adapted to acidity and may cope with low pH by expressing stress response genes and colonizing less acidic microenvironments. As a whole, our study underlines the impact of microenvironments on bacterial colonization and adaptation in CF infections.IMPORTANCEUnderstanding bacterial responses to physiological conditions is an important priority for combating opportunistic infections. The majority of CF patients succumb to inflammation and necrosis in the airways, arising from chronic infection due to ineffective mucociliary clearance. Steep pH gradients characterize the CF airways but are not often incorporated in standard microbiology culture conditions.Stenotrophomonas maltophiliais a prevalent CF opportunistic pathogen also found in many disparate environments, yet this bacterium’s contribution to CF lung damage and its response to changing environmental factors remain largely understudied. Here, we show that pH impacts the physiology and antibiotic susceptibility ofS. maltophilia, with implications for the development of relevantin vitromodels and assessment of antibiotic sensitivity.

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