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Sample records for acid ja accumulation

  1. Jasmonic acid/methyl jasmonate accumulate in wounded soybean hypocotyls and modulate wound gene expression.

    PubMed

    Creelman, R A; Tierney, M L; Mullet, J E

    1992-06-01

    Jasmonic acid (JA) and its methyl ester, methyl jasmonate (MeJA), are plant lipid derivatives that resemble mammalian eicosanoids in structure and biosynthesis. These compounds are proposed to play a role in plant wound and pathogen responses. Here we report the quantitative determination of JA/MeJA in planta by a procedure based on the use of [13C,2H3]MeJA as an internal standard. Wounded soybean (Glycine max [L] Merr. cv. Williams) stems rapidly accumulated MeJA and JA. Addition of MeJA to soybean suspension cultures also increased mRNA levels for three wound-responsive genes (chalcone synthase, vegetative storage protein, and proline-rich cell wall protein) suggesting a role for MeJA/JA in the mediation of several changes in gene expression associated with the plants' response to wounding.

  2. The tomato res mutant which accumulates JA in roots in non-stressed conditions restores cell structure alterations under salinity.

    PubMed

    Garcia-Abellan, José O; Fernandez-Garcia, Nieves; Lopez-Berenguer, Carmen; Egea, Isabel; Flores, Francisco B; Angosto, Trinidad; Capel, Juan; Lozano, Rafael; Pineda, Benito; Moreno, Vicente; Olmos, Enrique; Bolarin, Maria C

    2015-11-01

    Jasmonic acid (JA) regulates a wide spectrum of plant biological processes, from plant development to stress defense responses. The role of JA in plant response to salt stress is scarcely known, and even less known is the specific response in root, the main plant organ responsible for ionic uptake and transport to the shoot. Here we report the characterization of the first tomato (Solanum lycopersicum) mutant, named res (restored cell structure by salinity), that accumulates JA in roots prior to exposure to stress. The res tomato mutant presented remarkable growth inhibition and displayed important morphological alterations and cellular disorganization in roots and leaves under control conditions, while these alterations disappeared when the res mutant plants were grown under salt stress. Reciprocal grafting between res and wild type (WT) (tomato cv. Moneymaker) indicated that the main organ responsible for the development of alterations was the root. The JA-signaling pathway is activated in res roots prior to stress, with transcripts levels being even higher in control condition than in salinity. Future studies on this mutant will provide significant advances in the knowledge of JA role in root in salt-stress tolerance response, as well as in the energy trade-off between plant growth and response to stress.

  3. Priming for JA-dependent defenses using hexanoic acid is an effective mechanism to protect Arabidopsis against B. cinerea.

    PubMed

    Kravchuk, Zhana; Vicedo, Begonya; Flors, Víctor; Camañes, Gemma; González-Bosch, Carmen; García-Agustín, Pilar

    2011-03-01

    Soil drench treatments with hexanoic acid can effectively protect Arabidopsis plants against Botrytis cinerea through a mechanism based on a stronger and faster accumulation of JA-dependent defenses. Plants impaired in ethylene, salicylic acid, abscisic acid or glutathion pathways showed intact protection by hexanoic acid upon B. cinerea infection. Accordingly, no significant changes in the SA marker gene PR-1 in either the SA or ABA hormone balance were observed in the infected and treated plants. In contrast, the JA signaling pathway showed dramatic changes after hexanoic acid treatment, mainly when the pathogen was present. The impaired JA mutants, jin1-2 and jar1, were unable to display hexanoic acid priming against the necrotroph. In addition, hexanoic acid-treated plants infected with B. cinerea showed priming in the expression of the PDF1.2, PR-4 and VSP1 genes implicated in the JA pathways. Moreover, JA and OPDA levels were primed at early stages by hexanoic acid. Treatments also stimulated increased callose accumulation in response to the pathogen. Although callose accumulation has proved an effective IR mechanism against B. cinerea, it is apparently not essential to express hexanoic acid-induced resistance (HxAc-IR) because the mutant pmr4.1 (callose synthesis defective mutant) is protected by treatment. We recently described how hexanoic acid treatments can protect tomato plants against B. cinerea by stimulating ABA-dependent callose deposition and by priming OPDA and JA-Ile production. We clearly demonstrate here that Hx-IR is a dependent plant species, since this acid protects Arabidopsis plants against the same necrotroph by priming JA-dependent defenses without enhancing callose accumulation.

  4. Endogenous Bioactive Jasmonate Is Composed of a Set of (+)-7-iso-JA-Amino Acid Conjugates.

    PubMed

    Yan, Jianbin; Li, Suhua; Gu, Min; Yao, Ruifeng; Li, Yuwen; Chen, Juan; Yang, Mai; Tong, Jianhua; Xiao, Langtao; Nan, Fajun; Xie, Daoxin

    2016-12-01

    Jasmonates (JAs) regulate a wide range of plant defense and development processes. The bioactive JA is perceived by its receptor COI1 to trigger the degradation of JASMONATE ZIM-DOMAIN (JAZ) proteins and subsequently derepress the JAZ-repressed transcription factors for activation of expression of JA-responsive genes. So far, (+)-7-iso-JA-l-Ile has been the only identified endogenous bioactive JA molecule. Here, we designed coronafacic acid (CFA) conjugates with all the amino acids (CFA-AA) to mimic the JA amino acid conjugates, and revealed that (+)-7-iso-JA-Leu, (+)-7-iso-JA-Val, (+)-7-iso-JA-Met, and (+)-7-iso-JA-Ala are new endogenous bioactive JA molecules. Furthermore, our studies uncover the general characteristics for all the bioactive JA molecules, and provide a new strategy to synthetically generate novel active JA molecules.

  5. Coordinate expression of AOS genes and JA accumulation: JA is not required for initiation of closing layer in wound healing tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wounding induces a series of coordinated physiological responses essential for protection and healing of the damaged tissue. Wound-induced formation of jasmonic acid (JA) is important in defense responses in leaves, but comparatively little is known about the induction of JA biosynthesis and its ro...

  6. A chloroplast lipoxygenase is required for wound-induced jasmonic acid accumulation in Arabidopsis.

    PubMed

    Bell, E; Creelman, R A; Mullet, J E

    1995-09-12

    Plant lipoxygenases are thought to be involved in the biosynthesis of lipid-derived signaling molecules. The potential involvement of a specific Arabidopsis thaliana lipoxygenase isozyme, LOX2, in the biosynthesis of the plant growth regulators jasmonic acid (JA) and abscisic acid was investigated. Our characterization of LOX2 indicates that the protein is targeted to chloroplasts. The physiological role of this chloroplast lipoxygenase was analyzed in transgenic plants where cosuppression reduced LOX2 accumulation. The reduction in LOX2 levels caused no obvious changes in plant growth or in the accumulation of abscisic acid. However, the wound-induced accumulation of JA observed in control plants was absent in leaves of transgenic plants that lacked LOX2. Thus, LOX2 is required for the wound-induced synthesis of the plant growth regulator JA in leaves. We also examined the expression of a wound- and JA-inducible Arabidopsis gene, vsp, in transgenic and control plants. Leaves of transgenic plants lacking LOX2 accumulated less vsp mRNA than did control leaves in response to wounding. This result suggests that wound-induced JA (or some other LOX2-requiring component of the wound response pathway) is involved in the wound-induced regulation of this gene.

  7. Expression of a Flax Allene Oxide Synthase cDNA Leads to Increased Endogenous Jasmonic Acid (JA) Levels in Transgenic Potato Plants but Not to a Corresponding Activation of JA-Responding Genes.

    PubMed Central

    Harms, K.; Atzorn, R.; Brash, A.; Kuhn, H.; Wasternack, C.; Willmitzer, L.; Pena-Cortes, H.

    1995-01-01

    Both jasmonic acid (JA) and its methyl ester, methyl jasmonate (MeJA), are thought to be significant components of the signaling pathway regulating the expression of plant defense genes in response to various stresses. JA and MeJA are plant lipid derivatives synthesized from [alpha]-linolenic acid by a lipoxygenase-mediated oxygenation leading to 13-hydroperoxylinolenic acid, which is subsequently transformed by the action of allene oxide synthase (AOS) and additional modification steps. AOS converts lipoxygenase-derived fatty acid hydroperoxide to allene epoxide, which is the precursor for JA formation. Overexpression of flax AOS cDNA under the regulation of the cauliflower mosaic virus 35S promoter in transgenic potato plants led to an increase in the endogenous level of JA. Transgenic plants had six- to 12-fold higher levels of JA than the nontransformed plants. Increased levels of JA have been observed when potato and tomato plants are mechanically wounded. Under these conditions, the proteinase inhibitor II (pin2) genes are expressed in the leaves. Despite the fact that the transgenic plants had levels of JA similar to those found in nontransgenic wounded plants, pin2 genes were not constitutively expressed in the leaves of these plants. Transgenic plants with increased levels of JA did not show changes in water state or in the expression of water stress-responsive genes. Furthermore, the transgenic plants overexpressing the flax AOS gene, and containing elevated levels of JA, responded to wounding or water stress by a further increase in JA and by activating the expression of either wound- or water stress-inducible genes. Protein gel blot analysis demonstrated that the flax-derived AOS protein accumulated in the chloroplasts of the transgenic plants. PMID:12242357

  8. 12-oxo-phytodienoic acid accumulation during seed development represses seed germination in Arabidopsis.

    PubMed

    Dave, Anuja; Hernández, M Luisa; He, Zhesi; Andriotis, Vasilios M E; Vaistij, Fabián E; Larson, Tony R; Graham, Ian A

    2011-02-01

    Arabidopsis thaliana COMATOSE (CTS) encodes an ABC transporter involved in peroxisomal import of substrates for β-oxidation. Various cts alleles and mutants disrupted in steps of peroxisomal β-oxidation have previously been reported to exhibit a severe block on seed germination. Oxylipin analysis on cts, acyl CoA oxidase1 acyl CoA oxidase2 (acx1 acx2), and keto acyl thiolase2 dry seeds revealed that they contain elevated levels of 12-oxo-phytodienoic acid (OPDA), jasmonic acid (JA), and JA-Ile. Oxylipin and transcriptomic analysis showed that accumulation of these oxylipins occurs during late seed maturation in cts. Analysis of double mutants generated by crossing cts with mutants in the JA biosynthesis pathway indicate that OPDA, rather than JA or JA-Ile, contributes to the block on germination in cts seeds. We found that OPDA was more effective at inhibiting wild-type germination than was JA and that this effect was independent of CORONATINE INSENSITIVE1 but was synergistic with abscisic acid (ABA). Consistent with this, OPDA treatment increased ABA INSENSITIVE5 protein abundance in a manner that parallels the inhibitory effect of OPDA and OPDA+ABA on seed germination. These results demonstrate that OPDA acts along with ABA to regulate seed germination in Arabidopsis.

  9. Jasmonoyl isoleucine accumulation is needed for abscisic acid build-up in roots of Arabidopsis under water stress conditions.

    PubMed

    de Ollas, Carlos; Arbona, Vicent; Gómez-Cadenas, Aurelio

    2015-10-01

    Phytohormones are central players in sensing and signalling numerous environmental conditions like drought. In this work, hormone profiling together with gene expression of key enzymes involved in abscisic acid (ABA) and jasmonate biosynthesis were studied in desiccating Arabidopsis roots. Jasmonic acid (JA) content transiently increased after stress imposition whereas progressive and concomitant ABA and Jasmonoyl Isoleucine (JA-Ile) accumulations were detected. Molecular data suggest that, at least, part of the hormonal regulation takes place at the biosynthetic level. These observations also point to a possible involvement of jasmonates on ABA biosynthesis under stress. To test this hypothesis, mutants impaired in jasmonate biosynthesis (opr3, lox6 and jar1-1) and in JA-dependent signalling (coi1) were employed. Results showed that the early JA accumulation leading to JA-Ile build up was necessary for an ABA increase in roots under two different water stress conditions. Signal transduction between water stress-induced JA-Ile accumulation and COI1 is necessary for a full induction of the ABA biosynthesis pathway and subsequent hormone accumulation in roots of Arabidopsis plants. The present work adds a level of interaction between jasmonates and ABA at the biosynthetic level.

  10. Bromine accumulation in acidic black colluvial soils

    NASA Astrophysics Data System (ADS)

    Cortizas, Antonio Martínez; Vázquez, Cruz Ferro; Kaal, Joeri; Biester, Harald; Casais, Manuela Costa; Rodríguez, Teresa Taboada; Lado, Luis Rodríguez

    2016-02-01

    Recent investigations showed that bromine is incorporated to soil organic matter (SOM), its content increasing with humification. But few research was done on its long-term accumulation and the role played by pedogenetic processes, as those involved in organic matter stabilization. We investigated bromine content and distribution in four deep, acidic, organic-rich, Holocene soils from an oceanic area of Western Europe. Bromine concentrations (93-778 μg g-1) in the silt + clay (<50 μm) fraction were on average 3-times higher than those (17-250 μg g-1) in the fine earth (<2 mm), the former containing almost all bromine (90 ± 5%). Inventories were between 148 and 314 g m-2, indicating a rather large variability in a small area, and total estimated retention was low (6-16%). The degree of SOM bromination, expressed as the Br/C molar ratio, varied between 0.03 and 1.20 mmol Br/mol C. The ratio was highly correlated (n = 23, r2 0.88, p < 0.01) with the age of the SOM for the last ∼12 ka. Partial least squares modeling indicates that bromine concentration depends on the amount of organic matter stabilized as aluminium-OM associations, and to a lesser extent on soil acidity (pH) and iron-OM associations. Thus, at scales of thousands of years, bromine accumulation in acidic soils is linked to the pool of metal-clay-stabilized organic matter.

  11. Transcriptome Analysis in Haematococcus pluvialis: Astaxanthin Induction by Salicylic Acid (SA) and Jasmonic Acid (JA).

    PubMed

    Gao, Zhengquan; Li, Yan; Wu, Guanxun; Li, Guoqiang; Sun, Haifeng; Deng, Suzhen; Shen, Yicheng; Chen, Guoqiang; Zhang, Ruihao; Meng, Chunxiao; Zhang, Xiaowen

    2015-01-01

    Haematococcus pluvialis is an astaxanthin-rich microalga that can increase its astaxanthin production by salicylic acid (SA) or jasmonic acid (JA) induction. The genetic transcriptome details of astaxanthin biosynthesis were analyzed by exposing the algal cells to 25 mg/L of SA and JA for 1, 6 and 24 hours, plus to the control (no stress). Based on the RNA-seq analysis, 56,077 unigenes (51.7%) were identified with functions in response to the hormone stress. The top five identified subcategories were cell, cellular process, intracellular, catalytic activity and cytoplasm, which possessed 5600 (~9.99%), 5302 (~9.45%), 5242 (~9.35%), 4407 (~7.86%) and 4195 (~7.48%) unigenes, respectively. Furthermore, 59 unigenes were identified and assigned to 26 putative transcription factors (TFs), including 12 plant-specific TFs. They were likely associated with astaxanthin biosynthesis in Haematococcus upon SA and JA stress. In comparison, the up-regulation of differential expressed genes occurred much earlier, with higher transcript levels in the JA treatment (about 6 h later) than in the SA treatment (beyond 24 h). These results provide valuable information for directing metabolic engineering efforts to improve astaxanthin biosynthesis in H. pluvialis.

  12. Algal swimming velocities signal fatty acid accumulation.

    PubMed

    Hansen, Travis J; Hondzo, Miki; Mashek, Mara T; Mashek, Douglas G; Lefebvre, Paul A

    2013-01-01

    The use of microalgae for biofuel production will be beneficial to society if we can produce biofuels at large scales with minimal mechanical energy input in the production process. Understanding micro-algal physiological responses under variable environmental conditions in bioreactors is essential for the optimization of biofuel production. We demonstrate that measuring micro-algal swimming speed provides information on culture health and total fatty acid accumulation. Three strains of Chlamydomonas reinhardtii were grown heterotrophically on acetate and subjected to various levels of nitrogen starvation. Other nutrient levels were explored to determine their effect on micro-algal kinetics. Swimming velocities were measured with two-dimensional micro-particle tracking velocimetry. The results show an inverse linear relationship between normalized total fatty acid mass versus swimming speed of micro-algal cells. Analysis of RNA sequencing data confirms these results by demonstrating that the biological processes of cell motion and the generation of energy precursors are significantly down-regulated. Experiments demonstrate that changes in nutrient concentration in the surrounding media also affect swimming speed. The findings have the potential for the in situ and indirect assessment of lipid content by measuring micro-algal swimming kinetics.

  13. Trehalose accumulation enhances tolerance of Saccharomyces cerevisiae to acetic acid.

    PubMed

    Yoshiyama, Yoko; Tanaka, Koichi; Yoshiyama, Kohei; Hibi, Makoto; Ogawa, Jun; Shima, Jun

    2015-02-01

    Trehalose confers protection against various environmental stresses on yeast cells. In this study, trehalase gene deletion mutants that accumulate trehalose at high levels showed significant stress tolerance to acetic acid. The enhancement of trehalose accumulation can thus be considered a target in the breeding of acetic acid-tolerant yeast strains.

  14. SGT1 regulates wounding- and herbivory-induced jasmonic acid accumulation and Nicotiana attenuata's resistance to the specialist lepidopteran herbivore Manduca sexta.

    PubMed

    Meldau, Stefan; Baldwin, Ian T; Wu, Jianqiang

    2011-03-01

    • SGT1 (suppressor of G-two allele of SKP1) is a conserved protein in all eukaryotes and is crucial for resisting pathogens in humans and plants. We studied whether SGT1 is involved in the induced defense response of a native tobacco (Nicotiana attenuata) to its natural herbivore, Manduca sexta. • We diminished NaSGT1 transcription in N. attenuata using virus-induced gene silencing (VIGS) and analysed the induced defense responses after wounding and M. sexta elicitation. • Silencing NaSGT1 highly attenuates wounding- and herbivory-induced amounts of jasmonic acid (JA) and JA-isoleucine but elevates the concentration of salicylic acid. Chemical profiling reveals that NaSGT1-silenced plants are also compromised in their ability to accumulate JA precursors produced in chloroplasts. We show that the reduced JA accumulation in NaSGT1-silenced plants is independent of the elevated salicylic acid levels. NaSGT1-silenced plants have decreased contents of defensive metabolites and have compromised resistance to M. sexta larvae. Transcript analyses after methyl jasmonate (MeJA) treatment revealed that NaSGT1 is important for the normal regulation of MeJA-induced transcriptional responses. • This work demonstrates the importance of SGT1 in the regulatory network that deploys defense responses against herbivores, and highlights the significance of SGT1 in plants' responses to JA.

  15. Ascorbic acid transport and accumulation in human neutrophils

    SciTech Connect

    Washko, P.; Rotrosen, D.; Levine, M. )

    1989-11-15

    The transport, accumulation, and distribution of ascorbic acid were investigated in isolated human neutrophils utilizing a new ascorbic acid assay, which combined the techniques of high performance liquid chromatography and coulometric electrochemical detection. Freshly isolated human neutrophils contained 1.0-1.4 mM ascorbic acid, which was localized greater than or equal to 94% to the cytosol, was not protein bound, and was present only as ascorbic acid and not as dehydroascorbic acid. Upon addition of ascorbic acid to the extracellular medium in physiologic amounts, ascorbic acid was accumulated in neutrophils in millimolar concentrations. Accumulation was mediated by a high affinity and a low affinity transporter; both transporters were responsible for maintenance of concentration gradients as large as 50-fold. The high affinity transporter had an apparent Km of 2-5 microns by Lineweaver-Burk and Eadie-Hofstee analyses, and the low affinity transporter had an apparent Km of 6-7 mM by similar analyses. Each transporter was saturable and temperature dependent. In normal human blood the high affinity transporter should be saturated, whereas the low affinity transporter should be in its linear phase of uptake.

  16. MYB76 Inhibits Seed Fatty Acid Accumulation in Arabidopsis

    PubMed Central

    Duan, Shaowei; Jin, Changyu; Li, Dong; Gao, Chenhao; Qi, Shuanghui; Liu, Kaige; Hai, Jiangbo; Ma, Haoli; Chen, Mingxun

    2017-01-01

    The MYB family of transcription factors is important in regulatory networks controlling development, metabolism and responses to biotic and abiotic stresses in Arabidopsis. However, their role in regulating fatty acid accumulation in seeds is still largely unclear. Here, we found that MYB76, localized in the nucleus, was predominantly expressed in developing seeds during maturation. The myb76 mutation caused a significant increase in the amounts of total fatty acids and several major fatty acid compositions in mature seeds, suggesting that MYB76 functioned as an important repressor during seed oil biosynthesis. RNA sequencing and quantitative real-time PCR analysis revealed remarkable alteration of numerous genes involved in photosynthesis, fatty acid biosynthesis, modification, and degradation, and oil body formation in myb76 seeds at 12 days after pollination. These results help us to understand the novel function of MYB76 and provide new insights into the regulatory network of MYB transcriptional factors controlling seed oil accumulation in Arabidopsis. PMID:28270825

  17. Physiological Characteristics and Production of Folic Acid of Lactobacillus plantarum JA71 Isolated from Jeotgal, a Traditional Korean Fermented Seafood

    PubMed Central

    Lim, Sang-Dong

    2014-01-01

    Folic acid, one of the B group of vitamins, is an essential substance for maintaining the functions of the nervous system, and is also known to decrease the level of homocysteine in plasma. Homocysteine influences the lowering of the cognitive function in humans, and especially in elderly people. In order to determine the strains with a strong capacity to produce folic acid, 190 bacteria were isolated from various kinds of jeotgal and chungkuk-jang. In our test experiment, JA71 was found to contain 9.03μg/mL of folic acid after 24 h of incubation in an MRS broth. This showed that JA71 has the highest folic acid production ability compared to the other lactic acid bacteria that were isolated. JA71 was identified as Lactobacillus plantarum by the result of API carbohydrate fermentation pattern and 16s rDNA sequence. JA71 was investigated for its physiological characteristics. The optimum growth temperature of JA71 was 37℃, and the cultures took 12 h to reach pH 4.4. JA71 proved more sensitive to bacitracin when compared with fifteen different antibiotics, and showed most resistance to neomycin and vancomycin. Moreover, it was comparatively tolerant of bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus with restraint rates of 60.4%, 96.7%, and 76.2%, respectively. These results demonstrate that JA71 could be an excellent strain for application to functional products. PMID:26760752

  18. Metabolic Conversion of l-Ascorbic Acid to Oxalic Acid in Oxalate-accumulating Plants.

    PubMed

    Yang, J C; Loewus, F A

    1975-08-01

    l-Ascorbic acid-1-(14)C and its oxidation product, dehydro-l-ascorbic acid, produced labeled oxalic acid in oxalate-accumulating plants such as spinach seedlings (Spinacia oleracea) and the detached leaves of woodsorrel (Oxalis stricta and O. oregana), shamrock (Oxalis adenopylla), and begonia (Begonia evansiana). In O. oregana, conversion occurred equally well in the presence or absence of light. This relationship between l-ascorbic acid metabolism and oxalic acid formation must be given careful consideration in attempts to explain oxalic accumulation in plants.

  19. Metabolic Conversion of l-Ascorbic Acid to Oxalic Acid in Oxalate-accumulating Plants 1

    PubMed Central

    Yang, Joan C.; Loewus, Frank A.

    1975-01-01

    l-Ascorbic acid-1-14C and its oxidation product, dehydro-l-ascorbic acid, produced labeled oxalic acid in oxalate-accumulating plants such as spinach seedlings (Spinacia oleracea) and the detached leaves of woodsorrel (Oxalis stricta and O. oregana), shamrock (Oxalis adenopylla), and begonia (Begonia evansiana). In O. oregana, conversion occurred equally well in the presence or absence of light. This relationship between l-ascorbic acid metabolism and oxalic acid formation must be given careful consideration in attempts to explain oxalic accumulation in plants. PMID:16659288

  20. Bottlenecks in erucic acid accumulation in genetically engineered ultrahigh erucic acid Crambe abyssinica

    PubMed Central

    Guan, Rui; Lager, Ida; Li, Xueyuan; Stymne, Sten; Zhu, Li-Hua

    2014-01-01

    Erucic acid is a valuable industrial fatty acid with many applications. The main producers of this acid are today high erucic rapeseed (Brassica napus) and mustard (Brassica juncea), which have 45%–50% of erucic acid in their seed oils. Crambe abyssinica is an alternative promising producer of this acid as it has 55%–60% of erucic acid in its oil. Through genetic modification (GM) of three genes, we have previously increased the level of erucic acid to 71% (68 mol%) in Crambe seed oil. In this study, we further investigated different aspects of oil biosynthesis in the developing GM Crambe seeds in comparison with wild-type (Wt) Crambe, rapeseed and safflower (Carthamus tinctorius). We show that Crambe seeds have very low phosphatidylcholine-diacylglycerol interconversion, suggesting it to be the main reason why erucic acid is limited in the membrane lipids during oil biosynthesis. We further show that GM Crambe seeds have slower seed development than Wt, accompanied by slower oil accumulation during the first 20 days after flowering (DAF). Despite low accumulation of erucic acid during early stages of GM seed development, nearly 86 mol% of all fatty acids accumulated between 27 and 50 DAF was erucic acid, when 40% of the total oil is laid down. Likely bottlenecks in the accumulation of erucic acid during early stages of GM Crambe seed development are discussed. PMID:24119222

  1. Bottlenecks in erucic acid accumulation in genetically engineered ultrahigh erucic acid Crambe abyssinica.

    PubMed

    Guan, Rui; Lager, Ida; Li, Xueyuan; Stymne, Sten; Zhu, Li-Hua

    2014-02-01

    Erucic acid is a valuable industrial fatty acid with many applications. The main producers of this acid are today high erucic rapeseed (Brassica napus) and mustard (Brassica juncea), which have 45%-50% of erucic acid in their seed oils. Crambe abyssinica is an alternative promising producer of this acid as it has 55%-60% of erucic acid in its oil. Through genetic modification (GM) of three genes, we have previously increased the level of erucic acid to 71% (68 mol%) in Crambe seed oil. In this study, we further investigated different aspects of oil biosynthesis in the developing GM Crambe seeds in comparison with wild-type (Wt) Crambe, rapeseed and safflower (Carthamus tinctorius). We show that Crambe seeds have very low phosphatidylcholine-diacylglycerol interconversion, suggesting it to be the main reason why erucic acid is limited in the membrane lipids during oil biosynthesis. We further show that GM Crambe seeds have slower seed development than Wt, accompanied by slower oil accumulation during the first 20 days after flowering (DAF). Despite low accumulation of erucic acid during early stages of GM seed development, nearly 86 mol% of all fatty acids accumulated between 27 and 50 DAF was erucic acid, when 40% of the total oil is laid down. Likely bottlenecks in the accumulation of erucic acid during early stages of GM Crambe seed development are discussed.

  2. The biochemistry of citric acid accumulation by Aspergillus niger.

    PubMed

    Karaffa, L; Sándor, E; Fekete, E; Szentirmai, A

    2001-01-01

    Fungi, in particular Aspergilli, are well known for their potential to overproduce a variety of organic acids. These microorganisms have an intrinsic ability to accumulate these substances and it is generally believed that this provides the fungi with an ecological advantage, since they grow rather well at pH 3 to 5, while some species even tolerate pH values as low as 1.5. Organic acid production can be stimulated and in a number of cases conditions have been found that result in almost quantitative conversion of carbon substrate into acid. This is exploited in large-scale production of a number of organic acids like citric-, gluconic- and itaconic acid. Both in production volume as well as in knowledge available, citrate is by far the major organic acid. Citric acid (2-hydroxy-propane-1,2,3-tricarboxylic acid) is a true bulk product with an estimated global production of over 900 thousand tons in the year 2000. Till the beginning of the 20th century, it was exclusively extracted from lemons. Since the global market was dominated by an Italian cartel, other means of production were sought. Chemical synthesis was possible, but not suitable due to expensive raw materials and a complicated process with low yield. The discovery of citrate accumulation by Aspergillus niger led to a rapid development of a fermentation process, which only a decade later accounted for a large part of the global production. The application of citric acid is based on three of its properties: (1) acidity and buffer capacity, (2) taste and flavour, and (3) chelation of metal ions. Because of its three acid groups with pKa values of 3.1, 4.7 and 6.4, citrate is able to produce a very low pH in solution, but is also useful as a buffer over a broad range of pH values (2 to 7). Citric acid has a pleasant acid taste which leaves little aftertaste. It sometimes enhances flavour, but is also able to mask sweetness, such as the aspartame taste in diet beverages. Chelation of metal ions is a very

  3. Accumulation of Phosphatidic Acid Increases Vancomycin Resistance in Escherichia coli

    PubMed Central

    Sutterlin, Holly A.; Zhang, Sisi

    2014-01-01

    In Gram-negative bacteria, lipopolysaccharide (LPS) contributes to the robust permeability barrier of the outer membrane, preventing entry of toxic molecules such as antibiotics. Mutations in lptD, the beta-barrel component of the LPS transport and assembly machinery, compromise LPS assembly and result in increased antibiotic sensitivity. Here, we report rare vancomycin-resistant suppressors that improve barrier function of a subset of lptD mutations. We find that all seven suppressors analyzed mapped to the essential gene cdsA, which is responsible for the conversion of phosphatidic acid to CDP-diacylglycerol in phospholipid biosynthesis. These cdsA mutations cause a partial loss of function and, as expected, accumulate phosphatidic acid. We show that this suppression is not confined to mutations that cause defects in outer membrane biogenesis but rather that these cdsA mutations confer a general increase in vancomycin resistance, even in a wild-type cell. We use genetics and quadrupole time of flight (Q-TOF) liquid chromatography-mass spectrometry (LC-MS) to show that accumulation of phosphatidic acid by means other than cdsA mutations also increases resistance to vancomycin. We suggest that increased levels of phosphatidic acid change the physical properties of the outer membrane to impede entry of vancomycin into the periplasm, hindering access to its target, an intermediate required for the synthesis of the peptidoglycan cell wall. PMID:24957626

  4. Uptake and accumulation of exogenous docosahexaenoic acid by Chlorella.

    PubMed

    Hayashi, M; Yukino, T; Maruyama, I; Kido, S; Kitaoka, S

    2001-01-01

    Tuna oil or its hydrolysate was added to a culture of Chlorella for its nutritional fortification as a feed for rotifer. Exogenous docosahexaenoic acid (DHA) in its free form was taken up by the cells of Chlorella vulgaris strain K-22 and by other strains, but tuna oil was not taken up by the cells. Accumulated DHA was found by electron microscopy in the cells in oil droplets. All strains of Chlorella used in these experiments took up exogenous DHA into the cells. It seems that the structure of the cell wall did not affect the uptake of DHA into the Chlorella cells.

  5. Jasmonic acid accumulation and systemic photosynthetic and electrical changes in locally burned wild type tomato, ABA-deficient sitiens mutants and sitiens pre-treated by ABA.

    PubMed

    Hlavinka, Jan; Nožková-Hlaváčková, Vladimíra; Floková, Kristýna; Novák, Ondřej; Nauš, Jan

    2012-05-01

    Burning the terminal leaflet of younger tomato (Lycopersicon esculentum Mill.) leaf caused local and systemic changes in the surface electrical potential (SEP) and gas exchange (GE) parameters. The local and systemic accumulation of endogenous abscisic acid (ABA) and jasmonic acid (JA) was measured 85 min after burning. The experiments were conducted with wild type (WT) plants, ABA-deficient mutant sitiens (SIT) and ABA pre-treated SIT plants (SITA). First changes in SEP were detected within 1.5 min after burning and were followed by a decrease in GE parameters within 3-6 min in WT, SIT and SITA plants. GE and SEP time courses of SIT were different and wave amplitudes of SEP of SIT were lower compared to WT and SITA. ABA content in WT and SITA control plants was similar and substantially higher compared to SIT, JA content was similar among WT, SIT and SITA. While changes in the ABA content in systemic leaves have not been recorded after burning, the systemic JA content was substantially increased in WT and more in SIT and SITA. The results suggest that ABA content governs the systemic reaction of GE and the SEP shape upon local burning. ABA, JA and SEP participate in triggering the GE reaction. The ABA shortage in the SIT in the reaction to burning is partly compensated by an enhanced JA accumulation. This JA compensation is maintained even in SIT endogenously supplied with ABA. A correlation between the systemic JA content and changes in GE parameters or SEP was not found.

  6. Pipecolic acid enhances resistance to bacterial infection and primes salicylic acid and nicotine accumulation in tobacco.

    PubMed

    Vogel-Adghough, Drissia; Stahl, Elia; Návarová, Hana; Zeier, Juergen

    2013-11-01

    Distinct amino acid metabolic pathways constitute integral parts of the plant immune system. We have recently identified pipecolic acid (Pip), a lysine-derived non-protein amino acid, as a critical regulator of systemic acquired resistance (SAR) and basal immunity to bacterial infection in Arabidopsis thaliana. In Arabidopsis, Pip acts as an endogenous mediator of defense amplification and priming. For instance, Pip conditions plants for effective biosynthesis of the phenolic defense signal salicylic acid (SA), accumulation of the phytoalexin camalexin, and expression of defense-related genes. Here, we show that tobacco plants respond to leaf infection by the compatible bacterial pathogen Pseudomonas syringae pv tabaci (Pstb) with a significant accumulation of several amino acids, including Lys, branched-chain, aromatic, and amide group amino acids. Moreover, Pstb strongly triggers, alongside the biosynthesis of SA and increases in the defensive alkaloid nicotine, the production of the Lys catabolites Pip and α-aminoadipic acid. Exogenous application of Pip to tobacco plants provides significant protection to infection by adapted Pstb or by non-adapted, hypersensitive cell death-inducing P. syringae pv maculicola. Pip thereby primes tobacco for rapid and strong accumulation of SA and nicotine following bacterial infection. Thus, our study indicates that the role of Pip as an amplifier of immune responses is conserved between members of the rosid and asterid groups of eudicot plants and suggests a broad practical applicability for Pip as a natural enhancer of plant disease resistance.

  7. The crosstalk between Target of Rapamycin (TOR) and Jasmonic Acid (JA) signaling existing in Arabidopsis and cotton

    PubMed Central

    Song, Yun; Zhao, Ge; Zhang, Xueyan; Li, Linxuan; Xiong, Fangjie; Zhuo, Fengping; Zhang, Chaojun; Yang, Zuoren; Datla, Raju; Ren, Maozhi; Li, Fuguang

    2017-01-01

    Target of rapamycin (TOR) acts as an important regulator of cell growth, development and stress responses in most examined diploid eukaryotes. However, little is known about TOR in tetraploid species such as cotton. Here, we show that TORC1-S6K-RPS6, the major signaling components, are conserved and further expanded in cotton genome. Though the cotton seedlings are insensitive to rapamycin, AZD8055, the second-generation inhibitor of TOR, can significantly suppress the growth in cotton. Global transcriptome analysis revealed that genes associated with jasmonic acid (JA) biosynthesis and transduction were significantly altered in AZD8055 treated cotton seedlings, suggesting the potential crosstalk between TOR and JA signaling. Pharmacological and genetic approaches have been employed to get further insights into the molecular mechanism of the crosstalk between TOR and JA. Combination of AZD8055 with methyl jasmonate can synergistically inhibit cotton growth, and additionally JA levels were significantly increased when cotton seedlings were subjected to AZD8055. JA biosynthetic and signaling mutants including jar1, coi1-2 and myc2-2 displayed TOR inhibitor-resistant phenotypes, whereas COI1 overexpression transgenic lines and jaz10 exhibited sensitivity to AZD8055. Consistently, cotton JAZ can partially rescue TOR-suppressed phenotypes in Arabidopsis. These evidences revealed that the crosstalk between TOR and JA pathway operates in cotton and Arabidopsis. PMID:28374843

  8. Gamma amino butyric acid accumulation in medicinal plants without stress

    PubMed Central

    Anju, P.; Moothedath, Ismail; Rema Shree, Azhimala Bhaskaranpillai

    2014-01-01

    Introduction: Gamma amino butyric acid (GABA) is an important ubiquitous four carbon nonprotein amino acid with an amino group attached to gamma carbon instead of beta carbon. It exists in different organisms including bacteria, plants, and animals and plays a crucial role in humans by regulating neuronal excitability throughout the nervous system. It is directly responsible for the regulation of muscle tone and also effective in lowering stress, blood pressure, and hypertension. Aim and Objective: The aim of the study was to develop the fingerprint profile of selected medicinally and economically important plants having central nervous system (CNS) activity and to determine the quantity of GABA in the selected plants grown under natural conditions without any added stress. Materials and Methods: The high-performance thin layer chromatography analysis was performed on precoated silica gel plate 60F–254 plate (20 cm × 10 cm) in the form of bands with width 8 mm using Hamilton syringe (100 μl) using n-butanol, acetic acid, and water in the proportion 5:2:2 as mobile phase in a CAMAG chamber which was previously saturated for 30 min. CAMAG TLC scanner 3 was used for the densitometric scanning at 550 nm. Specific marker compounds were used for the quantification. Results and Conclusion: Among the screened medicinal plants, Zingiber officinale and Solanum torvum were found to have GABA. The percentage of GABA present in Z. officinale and S. torvum were found to be 0.0114% and 0.0119%, respectively. The present work confirmed that among the selected CNS active medicinal plants, only two plants contain GABA. We found a negative correlation with plant having CNS activity and accumulation of GABA. The GABA shunt is a conserved pathway in eukaryotes and prokaryotes but, although the role of GABA as a neurotransmitter in mammals is clearly established, its role in plants is still vague. PMID:25861139

  9. Methyl jasmonate induces lauric acid omega-hydroxylase activity and accumulation of CYP94A1 transcripts but does not affect epoxide hydrolase activities in vicia sativa seedlings

    PubMed

    Pinot; Benveniste; Sala n JP; Durst

    1998-12-01

    Treatment of etiolated Vicia sativa seedlings by the plant hormone methyl jasmonate (MetJA) led to an increase of cytochrome P450 content. Seedlings that were treated for 48 h in a 1 mM solution of MetJA stimulated omega-hydroxylation of 12:0 (lauric acid) 14-fold compared with the control (153 versus 11 pmol min-1 mg-1 protein, respectively). Induction was dose dependent. The increase of activity (2.7-fold) was already detectable after 3 h of treatment. Activity increased as a function of time and reached a steady level after 24 h. Northern-blot analysis revealed that the transcripts coding for CYP94A1, a fatty acid omega-hydroxylase, had already accumulated after 1 h of exposure to MetJA and was maximal between 3 and 6 h. Under the same conditions, a study of the enzymatic hydrolysis of 9,10-epoxystearic acid showed that both microsomal and soluble epoxide hydrolase activities were not affected by MetJA treatment.

  10. Priming of seeds with methyl jasmonate induced resistance to hemi-biotroph Fusarium oxysporum f.sp. lycopersici in tomato via 12-oxo-phytodienoic acid, salicylic acid, and flavonol accumulation.

    PubMed

    Król, P; Igielski, R; Pollmann, S; Kępczyńska, E

    2015-05-01

    Methyl jasmonate (MeJA) was tested by seed treatment for its ability to protect tomato seedlings against fusarium wilt caused by the soil-borne fungal pathogen Fusarium oxysporum f.sp. lycopersici. Isolated from Solanum lycopersicon L. seeds, cv. Beta fungus was identified as F. oxysporum f.sp. lycopersici Race 3 fungus by using phytopathological and molecular methods. MeJA applied at 0.01, 0.1 and 1 mM reduced spore germination and mycelial growth in vitro. Soaking of tomato seeds in MeJA solution at 0.1 mM for 1 h significantly enhanced the resistance level against the tested fungus in tomato seedlings 4 weeks after inoculation. The extracts from leaves of 15-day-old seedlings obtained from previously MeJA soaked seeds had the ability to inhibit in vitro spore germination of tested fungus. In these seedlings a significant increase in the levels phenolic compounds such as salicylic acid (SA), kaempferol and quercetin was observed. Up-regulation of phenylalanine ammonia-lyase (PAL5) and benzoic acid/salicylic acid carboxyl methyltransferase (BSMT) genes and down-regulation of the isochorysmate synthase (ICS) gene in response to exogenous MeJA application indicate that the phenylalanine ammonia-lyase (PAL), not the isochorismate (IC) pathway, is the primary route for SA production in tomato. Moreover, the increased accumulation of the flavonols quercetin and kaempferol appears closely related to the increase of PAL5, chalcone synthase (CHS) and flavonol synthase/flavanone 3-hydroxylase-like (FLS) genes. Elevated levels of salicylic acid in seedlings raised from MeJA-soaked seeds were simultaneously accompanied by a decrease of jasmonic acid, the precursor of MeJA, and an increase of 12-oxo-phytodienoic acid (OPDA), the precursor of jasmonic acid. The present results indicate that the priming of tomato seeds with 0.1mM MeJA before sowing enables the seedlings grown from these seeds to reduce the attack of the soil-borne fungal pathogen F. oxysporum f.sp. lycopersici

  11. Modelling malic acid accumulation in fruits: relationships with organic acids, potassium, and temperature.

    PubMed

    Lobit, Philippe; Genard, Michel; Soing, Patrick; Habib, Robert

    2006-01-01

    Malic acid production, degradation, and storage during fruit development have been modelled. The model assumes that malic acid content is determined essentially by the conditions of its storage in the mesocarp cells, and provides a simplified representation of the mechanisms involved in the accumulation of malate in the vacuole and their regulation by thermodynamic constraints. Solving the corresponding system of equations made it possible to predict the malic acid content of the fruit as a function of organic acids, potassium concentration, and temperature. The model was applied to peach fruit, and parameters were estimated from the data of fruit development monitored over 2 years. The predictions were in good agreement with experimental data. Simulations were performed to analyse the behaviour of the model in response to variations in composition and temperature.

  12. Accumulation potentials of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in maize (Zea mays).

    PubMed

    Krippner, Johanna; Falk, Sandy; Brunn, Hubertus; Georgii, Sebastian; Schubert, Sven; Stahl, Thorsten

    2015-04-15

    Uptake of perfluoroalkyl acids (PFAAs) by maize represents a potential source of exposure for humans, either directly or indirectly via feed for animals raised for human consumption. The aim of the following study was, therefore, to determine the accumulation potential of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in maize (Zea mays). Two different concentrations of PFAAs were applied as aqueous solution to the soil to attain target concentrations of 0.25 mg or 1.00 mg of PFAA per kg of soil. Maize was grown in pots, and after harvesting, PFAA concentrations were measured in the straw and kernels of maize. PFCA and PFSA concentrations of straw decreased significantly with increasing chain length. In maize kernels, only PFCAs with a chain length ≤ C8 as well as perfluorobutanesulfonic acid (PFBS) were detected. The highest soil-to-plant transfer for both straw and kernels was determined for short-chained PFCAs and PFSAs.

  13. Aminomethylphosphonic acid accumulation in plant species treated with glyphosate.

    PubMed

    Reddy, Krishna N; Rimando, Agnes M; Duke, Stephen O; Nandula, Vijay K

    2008-03-26

    Aminomethylphosphonic acid (AMPA) is the most frequently detected metabolite of glyphosate in plants. The objective of this study was to determine if there is any correlation of metabolism of glyphosate to AMPA in different plant species and their natural level of resistance to glyphosate. Greenhouse studies were conducted to determine the glyphosate I 50 values (rate required to cause a 50% reduction in plant growth) and to quantify AMPA and shikimate concentrations in selected leguminous and nonleguminous species treated with glyphosate at respective I 50 rates. Coffee senna [ Cassia occidentalis (L.) Link] was the most sensitive ( I 50 = 75 g/ha) and hemp sesbania [ Sesbania herbacea (P.Mill.) McVaugh] was the most resistant ( I 50 = 456 g/ha) to glyphosate. Hemp sesbania was 6-fold and Illinois bundleflower [ Desmanthus illinoensis (Michx.) MacM. ex B.L.Robins. & Fern.] was 4-fold more resistant to glyphosate than coffee senna. Glyphosate was present in all plant species, and its concentration ranged from 0.308 to 38.7 microg/g of tissue. AMPA was present in all leguminous species studied except hemp sesbania. AMPA concentration ranged from 0.119 to 4.77 microg/g of tissue. Shikimate was present in all plant species treated with glyphosate, and levels ranged from 0.053 to 16.5 mg/g of tissue. Non-glyphosate-resistant (non-GR) soybean accumulated much higher shikimate than glyphosate-resistant (GR) soybean. Although some leguminous species were found to be more resistant to glyphosate than others, and there was considerable variation between species in the glyphosate to AMPA levels found, metabolism of glyphosate to AMPA did not appear to be a common factor in explaining natural resistance levels.

  14. Accumulator

    NASA Technical Reports Server (NTRS)

    Fenwick, J. R.; Karigan, G. H. (Inventor)

    1977-01-01

    An accumulator particularly adapted for use in controlling the pressure of a stream of fluid in its liquid phase utilizing the fluid in its gaseous phase was designed. The accumulator is characterized by a shell defining a pressure chamber having an entry throat for a liquid and adapted to be connected in contiguous relation with a selected conduit having a stream of fluid flowing through the conduit in its liquid phase. A pressure and volume stabilization tube, including an array of pressure relief perforations is projected into the chamber with the perforations disposed adjacent to the entry throat for accommodating a discharge of the fluid in either gaseous or liquid phases, while a gas inlet and liquid to gas conversion system is provided, the chamber is connected with a source of the fluid for continuously pressuring the chamber for controlling the pressure of the stream of liquid.

  15. Accumulated analyses of amino acid precursors in returned lunar samples

    NASA Technical Reports Server (NTRS)

    Fox, S. W.; Harada, K.; Hare, P. E.

    1973-01-01

    Six amino acids (glycine, alanine, aspartic acid, glutamic acid, serine, and threonine) obtained by hydrolysis of extracts have been quantitatively determined in ten collections of fines from five Apollo missions. Although the amounts found, 7-45 ng/g, are small, the lunar amino acid/carbon ratios are comparable to those of the carbonaceous chondrites, Murchison and Murray, as analyzed by the same procedures. Since both the ratios of amino acid to carbon, and the four or five most common types of proteinous amino acid found, are comparable for the two extraterrestrial sources despite different cosmophysical histories of the moon and meteorites, common cosmochemical processes are suggested.

  16. Kidney triglyceride accumulation in the fasted mouse is dependent upon serum free fatty acids.

    PubMed

    Scerbo, Diego; Son, Ni-Huiping; Sirwi, Alaa; Zeng, Lixia; Sas, Kelli M; Cifarelli, Vincenza; Schoiswohl, Gabriele; Huggins, Lesley-Ann; Gumaste, Namrata; Hu, Yunying; Pennathur, Subramaniam; Abumrad, Nada A; Kershaw, Erin E; Hussain, M Mahmood; Susztak, Katalin; Goldberg, Ira J

    2017-04-12

    Lipid accumulation is a pathological feature of every type of kidney injury. Despite this striking histological feature, physiological accumulation of lipids in the kidney is poorly understood. We studied whether the accumulation of lipids in the fasted kidney are derived from lipoproteins or non-esterified fatty acids (NEFAs). With overnight fasting, kidneys accumulated triglyceride but had reduced levels of ceramide and glycosphingolipid species. Fasting led to a nearly 5-fold increase in kidney uptake of plasma [14C]oleic acid. Increasing circulating NEFAs using a beta adrenergic receptor agonist caused a 15-fold greater accumulation of lipid in the kidney, while mice with reduced NEFAs due to adipose tissue deficiency of adipose triglyceride lipase had reduced triglycerides. Cd36 mRNA increased 2-fold, and Angptl4, an LpL inhibitor, increased 10-fold. Fasting-induced kidney lipid accumulation was not affected by inhibition of LpL with poloxamer 407 or by use of mice with induced genetic LpL deletion. Despite the increase in CD36 expression with fasting, genetic loss of CD36 did not alter fatty acid uptake or triglyceride accumulation. Our data demonstrate that fasting-induced triglyceride accumulation in the kidney correlates with the plasma concentrations of NEFAs, but is not due to uptake of lipoprotein lipids and does not involve the fatty acid transporter CD36.

  17. Physcomitrella patens activates reinforcement of the cell wall, programmed cell death and accumulation of evolutionary conserved defence signals, such as salicylic acid and 12-oxo-phytodienoic acid, but not jasmonic acid, upon Botrytis cinerea infection.

    PubMed

    Ponce De León, Inés; Schmelz, Eric A; Gaggero, Carina; Castro, Alexandra; Álvarez, Alfonso; Montesano, Marcos

    2012-10-01

    The moss Physcomitrella patens is an evolutionarily basal model system suitable for the analysis of plant defence responses activated after pathogen assault. Upon infection with the necrotroph Botrytis cinerea, several defence mechanisms are induced in P. patens, including the fortification of the plant cell wall by the incorporation of phenolic compounds and the induced expression of related genes. Botrytis cinerea infection also activates the accumulation of reactive oxygen species and cell death with hallmarks of programmed cell death in moss tissues. Salicylic acid (SA) levels also increase after fungal infection, and treatment with SA enhances transcript accumulation of the defence gene phenylalanine ammonia-lyase (PAL) in P. patens colonies. The expression levels of the genes involved in 12-oxo-phytodienoic acid (OPDA) synthesis, including lipoxygenase (LOX) and allene oxide synthase (AOS), increase in P. patens gametophytes after pathogen assault, together with a rise in free linolenic acid and OPDA concentrations. However, jasmonic acid (JA) could not be detected in healthy or infected tissues of this plant. Our results suggest that, although conserved defence signals, such as SA and OPDA, are synthesized and are probably involved in the defence response of P. patens against B. cinerea infection, JA production appears to be missing. Interestingly, P. patens responds to OPDA and methyl jasmonate by reducing moss colony growth and rhizoid length, suggesting that jasmonate perception is present in mosses. Thus, P. patens can provide clues with regard to the evolution of different defence pathways in plants, including signalling and perception of OPDA and jasmonates in nonflowering and flowering plants.

  18. RuBPCase activase mediates growth-defense tradeoffs: Silencing RCA redirects JA flux from JA-Ile to MeJA to attenuate induced defense responses in Nicotiana attenuata

    PubMed Central

    Mitra, Sirsha; Baldwin, Ian T.

    2014-01-01

    Summary RuBPCase activase (RCA), an abundant photosynthetic protein is strongly down-regulated in response to Manduca sexta’s oral secretion (OS) in Nicotiana attenuata. RCA-silenced plants are impaired not only in photosynthetic capacity and growth, but also in jasmonic acid (JA)-isoleucine (Ile) signaling, and herbivore resistance mediated by JA-Ile dependent defense traits. These responses are consistent with a resource-based growth-defense trade-off. Since JA+Ile-supplementation of OS restored WT levels of JA-Ile, defenses and resistance to M. sexta, but OS supplemented individually with JA- or Ile did not, the JA-Ile deficiency of RCA-silenced plants could not be attributed to lower JA or Ile pools or JAR4/6 conjugating activity. Similar levels of JA-Ile derivatives after OS elicitation indicated unaltered JA-Ile turnover and lower levels of other JA-conjugates ruled out competition from other conjugation reactions. RCA-silenced plants accumulated more methyl jasmonate (MeJA) after OS elicitation, which corresponded with increased jasmonate methyltransferase (JMT) activity. RCA-silencing phenocopies JMT over-expression, wherein elevated JMT activity redirects OS-elicited JA flux towards inactive MeJA, creating a JA sink which depletes JA-Ile and its associated defense responses. Hence RCA plays an additional non-photosynthetic role in attenuating JA-mediated defenses and their associated costs potentially allowing plants to anticipate resource-based constraints on growth before they actually occur. PMID:24491116

  19. Process strategies to maximize lipid accumulations of novel yeast in acid and base treated hydrolyzates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oleaginous yeasts can accumulate up to 70% of cell biomass as lipids, predominantly as triacylglycerols. Yeast lipid fatty acid profiles have been reported to be similar to that of vegetable oils and consist primarily of oleic, palmitic, stearic, and linoleic acids. This capability provides the oppo...

  20. JA, a new type of polyunsaturated fatty acid isolated from Juglans mandshurica Maxim, limits the survival and induces apoptosis of heptocarcinoma cells.

    PubMed

    Gao, Xiu-Li; Lin, Hua; Zhao, Wei; Hou, Ya-Qin; Bao, Yong-Li; Song, Zhen-Bo; Sun, Lu-Guo; Tian, Shang-Yi; Liu, Biao; Li, Yu-Xin

    2016-03-01

    Juglans mandshurica Maxim (Juglandaceae) is a famous folk medicine for cancer treatment and some natural compounds isolated from it have been studied extensively. Previously we isolated a type of ω-9 polyunsaturated fatty acid (JA) from the bark of J. mandshurica, however little is known about its activity and the underlying mechanisms. In this study, we studied anti-tumor activity of JA on several human cancer cell lines. Results showed that JA is cytotoxic to HepG2, MDA-MB-231, SGC-7901, A549 and Huh7 cells at a concentration exerting minimal toxic effects on L02 cells. The selective toxicity of JA was better than other classical anti-cancer drugs. Further investigation indicated that JA could induce cell apoptosis, characterized by chromatin condensation, DNA fragmentation and activation of the apoptosis-associated proteins such as Caspase-3 and PARP-1. Moreover, we investigated the cellular apoptosis pathway involved in the apoptosis process in HepG2 cells. We found that proteins involved in mitochondrion (cleaved-Caspase-9, Apaf-1, HtrA2/Omi, Bax, and Mitochondrial Bax) and endocytoplasmic reticulum (XBP-1s, GRP78, cleaved-Caspase-7 and cleaved-Caspase-12) apoptotic pathways were up-regulated when cells were treated by JA. In addition, a morphological change in the mitochondrion was detected. Furthermore, we found that JA could inhibit DNA synthesis and induce G2/M cell cycle arrest. The expression of G2-to-M transition related proteins, such as CyclinB1 and phosphorylated-CDK1, were reduced. In contrast, the G2-to-M inhibitor p21 was increased in JA-treated cells. Overall, our results suggest that JA can induce mitochondrion- and endocytoplasmic reticulum-mediated apoptosis, and G2/M phase arrest in HepG2 cells, making it a promising therapeutic agent against hepatoma.

  1. Higher transcription levels in ascorbic acid biosynthetic and recycling genes were associated with higher ascorbic acid accumulation in blueberry.

    PubMed

    Liu, Fenghong; Wang, Lei; Gu, Liang; Zhao, Wei; Su, Hongyan; Cheng, Xianhao

    2015-12-01

    In our preliminary study, the ripe fruits of two highbush blueberry (Vaccinium corymbosum L.) cultivars, cv 'Berkeley' and cv 'Bluecrop', were found to contain different levels of ascorbic acid. However, factors responsible for these differences are still unknown. In the present study, ascorbic acid content in fruits was compared with expression profiles of ascorbic acid biosynthetic and recycling genes between 'Bluecrop' and 'Berkeley' cultivars. The results indicated that the l-galactose pathway was the predominant route of ascorbic acid biosynthesis in blueberry fruits. Moreover, higher expression levels of the ascorbic acid biosynthetic genes GME, GGP, and GLDH, as well as the recycling genes MDHAR and DHAR, were associated with higher ascorbic acid content in 'Bluecrop' compared with 'Berkeley', which indicated that a higher efficiency ascorbic acid biosynthesis and regeneration was likely to be responsible for the higher ascorbic acid accumulation in 'Bluecrop'.

  2. An oleaginous bacterium that intrinsically accumulates long-chain free Fatty acids in its cytoplasm.

    PubMed

    Katayama, Taiki; Kanno, Manabu; Morita, Naoki; Hori, Tomoyuki; Narihiro, Takashi; Mitani, Yasuo; Kamagata, Yoichi

    2014-02-01

    Medium- and long-chain fatty acids are present in organisms in esterified forms that serve as cell membrane constituents and storage compounds. A large number of organisms are known to accumulate lipophilic materials as a source of energy and carbon. We found a bacterium, designated GK12, that intrinsically accumulates free fatty acids (FFAs) as intracellular droplets without exhibiting cytotoxicity. GK12 is an obligatory anaerobic, mesophilic lactic acid bacterium that was isolated from a methanogenic reactor. Phylogenetic analysis based on 16S rRNA gene sequences showed that GK12 is affiliated with the family Erysipelotrichaceae in the phylum Firmicutes but is distantly related to type species in this family (less than 92% similarity in 16S rRNA gene sequence). Saturated fatty acids with carbon chain lengths of 14, 16, 18, and 20 were produced from glucose under stress conditions, including higher-than-optimum temperatures and the presence of organic solvents that affect cell membrane integrity. FFAs were produced at levels corresponding to up to 25% (wt/wt) of the dry cell mass. Our data suggest that FFA accumulation is a result of an imbalance between excess membrane fatty acid biosynthesis due to homeoviscous adaptation and limited β-oxidation activity due to anaerobic growth involving lactic acid fermentation. FFA droplets were not further utilized as an energy and carbon source, even under conditions of starvation. A naturally occurring bacterium that accumulates significant amounts of long-chain FFAs with noncytotoxicity would provide useful strategies for microbial biodiesel production.

  3. Sinapic acid ester metabolism in wild type and a sinapoylglucose-accumulating mutant of arabidopsis.

    PubMed Central

    Lorenzen, M; Racicot, V; Strack, D; Chapple, C

    1996-01-01

    Sinapoylmalate is one of the major phenylpropanoid metabolites that is accumulated in the vegetative tissue of Arabidopsis thaliana. A thin-layer chromatography-based mutant screen identified two allelic mutant lines that accumulated sinapoylglucose in their leaves in place of sinapoylmalate. Both mutations were found to be recessive and segregated as single Mendelian genes. These mutants define a new locus called SNG1 for sinapoylglucose accumulator. Plants that are homozygous for the sng1 mutation accumulate normal levels of malate in their leaves but lack detectable levels of the final enzyme in sinapate ester biosynthesis, sinapoylglucose:malate sinapoyltransferase. A study of wild-type and sng1 seedlings found that sinapic acid ester biosynthesis in Arabidopsis is developmentally regulated and that the accumulation of sinapate esters is delayed in sng1 mutant seedlings. PMID:8972602

  4. Intercellular salicylic acid accumulation during compatible and incompatible Arabidopsis-Pseudomonas syringae interactions.

    PubMed

    Wilson, Daniel C; Carella, Philip; Cameron, Robin K

    2014-01-01

    The phytohormone salicylic acid (SA) plays an important role in several disease resistance responses. During the Age-Related Resistance (ARR) response that occurs in mature Arabidopsis responding to Pseudomonas syringae pv tomato (Pst), SA accumulates in the intercellular space where it may act as an antimicrobial agent. Recently we measured intracellular and intercellular SA levels in young, ARR-incompetent plants responding to virulent and avirulent strains of Pst to determine if intercellular SA accumulation is a component of additional defense responses to Pst. In young plants virulent Pst suppressed both intra- and intercellular SA accumulation in a coronatine-dependent manner. In contrast, high levels of intra- and intercellular SA accumulated in response to avirulent Pst. Our results support the idea that SA accumulation in the intercellular space is an important component of multiple defense responses. Future research will include understanding how mature plants counteract the effects of coronatine during the ARR response.

  5. The mealybug Phenacoccus solenopsis suppresses plant defense responses by manipulating JA-SA crosstalk

    PubMed Central

    Zhang, Peng-Jun; Huang, Fang; Zhang, Jin-Ming; Wei, Jia-Ning; Lu, Yao-Bin

    2015-01-01

    Induced plant defenses against herbivores are modulated by jasmonic acid-, salicylic acid-, and ethylene-signaling pathways. Although there is evidence that some pathogens suppress plant defenses by interfering with the crosstalk between different signaling pathways, such evidence is scarce for herbivores. Here, we demonstrate that the mealybug Phenacoccus solenopsis suppresses the induced defenses in tomato. We found that exogenous JA, but not SA, significantly decreased mealybug feeding time and reduced nymphal performance. In addition, constitutive activation of JA signaling in 35s::prosys plants reduced mealybug survival. These data indicate that the JA signaling pathway plays a key role in mediating the defense responses against P. solenopsis. We also found that mealybug feeding decreased JA production and JA-dependent defense gene expression, but increased SA accumulation and SA-dependent gene expression. In SA-deficient plants, mealybug feeding did not suppress but activated JA accumulation, indicating that the suppression of JA-regulated defenses depends on the SA signaling pathway. Mealybugs benefit from suppression of JA-regulated defenses by exhibiting enhanced nymphal performance. These findings confirm that P. solenopsis manipulates plants for its own benefits by modulating the JA-SA crosstalk and thereby suppressing induced defenses. PMID:25790868

  6. Arachidonic acid accumulates in the stromal macrophages during thymus involution in diabetes.

    PubMed

    Gruia, Alexandra T; Barbu-Tudoran, Lucian; Mic, Ani A; Ordodi, Valentin L; Paunescu, Virgil; Mic, Felix A

    2011-07-01

    Diabetes is a debilitating disease with chronic evolution that affects many tissues and organs over its course. Thymus is an organ that is affected early after the onset of diabetes, gradually involuting until it loses most of its thymocyte populations. We show evidence of accumulating free fatty acids with generation of eicosanoids in the diabetic thymus and we present a possible mechanism for the involution of the organ during the disease. Young rats were injected with streptozotocin and their thymuses examined for cell death by flow cytometry and TUNEL reaction. Accumulation of lipids in the diabetic thymus was investigated by histology and electron microscopy. The identity and quantitation of accumulating lipids was done with gas chromatography-mass spectrometry and liquid chromatography. The expression and dynamics of the enzymes were monitored via immunohistochemistry. Diabetes causes thymus involution by elevating the thymocyte apoptosis. Exposure of thymocytes to elevated concentration of glucose causes apoptosis. After the onset of diabetes, there is a gradual accumulation of free fatty acids in the stromal macrophages including arachidonic acid, the substrate for eicosanoids. The eicosanoids do not cause thymocyte apoptosis but administration of a cyclooxygenase inhibitor reduces the staining for ED1, a macrophage marker whose intensity correlates with phagocytic activity. Diabetes causes thymus involution that is accompanied by accumulation of free fatty acids in the thymic macrophages. Excess glucose is able to induce thymocyte apoptosis but eicosanoids are involved in the chemoattraction of macrophage to remove the dead thymocytes.

  7. Coexpressing Escherichia coli Cyclopropane Synthase with Sterculia foetida Lysophosphatidic Acid Acyltransferase Enhances Cyclopropane Fatty Acid Accumulation1[W][OPEN

    PubMed Central

    Yu, Xiao-Hong; Prakash, Richa Rawat; Sweet, Marie; Shanklin, John

    2014-01-01

    Cyclopropane fatty acids (CPAs) are desirable as renewable chemical feedstocks for the production of paints, plastics, and lubricants. Toward our goal of creating a CPA-accumulating crop, we expressed nine higher plant cyclopropane synthase (CPS) enzymes in the seeds of fad2fae1 Arabidopsis (Arabidopsis thaliana) and observed accumulation of less than 1% CPA. Surprisingly, expression of the Escherichia coli CPS gene resulted in the accumulation of up to 9.1% CPA in the seed. Coexpression of a Sterculia foetida lysophosphatidic acid acyltransferase (SfLPAT) increases CPA accumulation up to 35% in individual T1 seeds. However, seeds with more than 9% CPA exhibit wrinkled seed morphology and reduced size and oil accumulation. Seeds with more than 11% CPA exhibit strongly decreased seed germination and establishment, and no seeds with CPA more than 15% germinated. That previous reports suggest that plant CPS prefers the stereospecific numbering (sn)-1 position whereas E. coli CPS acts on sn-2 of phospholipids prompted us to investigate the preferred positions of CPS on phosphatidylcholine (PC) and triacylglycerol. Unexpectedly, in planta, E. coli CPS acts primarily on the sn-1 position of PC; coexpression of SfLPAT results in the incorporation of CPA at the sn-2 position of lysophosphatidic acid. This enables a cycle that enriches CPA at both sn-1 and sn-2 positions of PC and results in increased accumulation of CPA. These data provide proof of principle that CPA can accumulate to high levels in transgenic seeds and sets the stage for the identification of factors that will facilitate the movement of CPA from PC into triacylglycerol to produce viable seeds with additional CPA accumulation. PMID:24204024

  8. Effect of acetic acid on lipid accumulation by glucose-fed activated sludge cultures

    SciTech Connect

    Mondala, Andro; Hernandez, Rafael; French, Todd; McFarland, Linda; Sparks, Darrell; Holmes, William; Haque, Monica

    2012-01-01

    The effect of acetic acid, a lignocellulose hydrolysis by-product, on lipid accumulation by activated sludge cultures grown on glucose was investigated. This was done to assess the possible application of lignocellulose as low-cost and renewable fermentation substrates for biofuel feedstock production. Results: Biomass yield was reduced by around 54% at a 2 g L -1 acetic acid dosage but was increased by around 18% at 10 g L -1 acetic acid dosage relative to the control run. The final gravimetric lipid contents at 2 and 10 g L -1 acetic acid levels were 12.5 + 0.7% and 8.8 + 3.2% w/w, respectively, which were lower than the control (17.8 + 2.8% w/w). However, biodiesel yields from activated sludge grown with acetic acid (5.6 + 0.6% w/w for 2 g L -1 acetic acid and 4.2 + 3.0% w/w for 10 g L -1 acetic acid) were higher than in raw activated sludge (1-2% w/w). The fatty acid profiles of the accumulated lipids were similar with conventional plant oil biodiesel feedstocks. Conclusions: Acetic acid enhanced biomass production by activated sludge at high levels but reduced lipid production. Further studies are needed to enhance acetic acid utilization by activated sludge microorganisms for lipid biosynthesis.

  9. Fatty acid accumulation in the yeast Sporidiobolus salmonicolor during batch production of gamma-decalactone.

    PubMed

    Feron, G; Dufossé, L; Mauvais, G; Bonnarme, P; Spinnler, H E

    1997-04-01

    This paper provides new information about the metabolism of various fatty acids and gamma-decalactone production by yeast. An analysis of the fatty acid composition of the yeast Sporidiobolus salmonicolor during batch production of lactone with ricinoleic acid methyl ester as a precursor showed an accumulation of the gamma-decalactone precursor inside the cells. Electron microscopy of the yeasts showed the presence of large internal inclusions leading to membrane and organelle lysis and, consequently, death of the yeast. S. salmonicolor cultivated with methyl oleate did not produce gamma-decalactone and is viable during the whole culture. Analysis of the long chain fatty acid fraction showed incorporation of methyl oleate.

  10. Abscisic Acid accumulates at positive turgor potential in excised soybean seedling growing zones.

    PubMed

    Creelman, R A; Mullet, J E

    1991-04-01

    Abscisic acid (ABA) accumulated in soybean (Glycine max [L.] Merr. cv Williams) hypocotyl elongating regions when seedlings were transferred to low water potential vermiculite (Psi = -0.3 megapascals) even though positive turgor is retained in this tissue. Accumulation of ABA in growing zones could occur from de novo biosynthesis within this tissue or transport from adjacent nongrowing zones. Both growing and nongrowing hypocotyl and root tissues accumulated significant levels of ABA when excised and dehydrated to reduce turgor. Surprisingly, excised growing zones (which experienced no water loss) also accumulated ABA when incubated in darkness for 4 hours at 100% relative humidity and 29 degrees C. Induction of ABA accumulation in the excised elongating region of the hypocotyl was not caused by disruption of root pressure or wounding. While excision of hypocotyl elongating regions induced ABA accumulation, no change in either extensin or p33 mRNA levels was observed. Accumulation of extensin or p33 mRNA required more severe wounding. This suggests that ABA is not involved in the response of these genes in wounded tissue and that wound signals are not causing ABA accumulation in excised tissue. Accumulation of ABA in excised elongating regions was correlated with growth inhibition and a decline in turgor to the yield threshold (Psi;(p) = 0.37 megapascals; R Matyssek, S Maruyama, JS Boyer [1988] Plant Physiol 86: 1163-1167). Inhibiting hypocotyl growth by transferring seedlings to lower temperatures or light did not cause ABA accumulation. We conclude that induction of ABA accumulation in growing zones is more sensitive to changes in turgor than the induction which occurs in mature tissues.

  11. Salinity Stress Is Beneficial to the Accumulation of Chlorogenic Acids in Honeysuckle (Lonicera japonica Thunb.)

    PubMed Central

    Yan, Kun; Cui, Mingxing; Zhao, Shijie; Chen, Xiaobing; Tang, Xiaoli

    2016-01-01

    Honeysuckle (Lonicera japonica Thunb.) is a traditional medicinal plant in China that is particularly rich in chlorogenic acids, which are phenolic compounds with various medicinal properties. This study aimed to examine the effects of salinity stress on accumulation of chlorogenic acids in honeysuckle, through hydroponic experiments and field trials, and to examine the mechanisms underlying the effects. NaCl stress stimulated the transcription of genes encoding key enzymes in the synthesis of chlorogenic acids in leaves; accordingly, the concentrations of chlorogenic acids in leaves were significantly increased under NaCl stress, as was antioxidant activity. Specifically, the total concentration of leaf chlorogenic acids was increased by 145.74 and 50.34% after 30 days of 150 and 300 mM NaCl stress, respectively. Similarly, the concentrations of chlorogenic acids were higher in the leaves of plants in saline, compared with non-saline, plots, with increases in total concentrations of chlorogenic acids of 56.05 and 105.29% in October 2014 and 2015, respectively. Despite leaf biomass reduction, absolute amounts of chlorogenic acids per plant and phenylalanine ammonia-lyase (PAL) activity were significantly increased by soil salinity, confirming that the accumulation of chlorogenic acids in leaves was a result of stimulation of their synthesis under salinity stress. Soil salinity also led to elevated chlorogenic acid concentrations in honeysuckle flower buds, with significant increases in total chlorogenic acids concentration of 22.42 and 25.14% in May 2014 and 2015, respectively. Consistent with biomass reduction, the absolute amounts of chlorogenic acid per plant declined in flower buds of plants exposed to elevated soil salinity, with no significant change in PAL activity. Thus, salinity-induced chlorogenic acid accumulation in flower buds depended on an amplification effect of growth reduction. In conclusion, salinity stress improved the medicinal quality of

  12. Salinity Stress Is Beneficial to the Accumulation of Chlorogenic Acids in Honeysuckle (Lonicera japonica Thunb.).

    PubMed

    Yan, Kun; Cui, Mingxing; Zhao, Shijie; Chen, Xiaobing; Tang, Xiaoli

    2016-01-01

    Honeysuckle (Lonicera japonica Thunb.) is a traditional medicinal plant in China that is particularly rich in chlorogenic acids, which are phenolic compounds with various medicinal properties. This study aimed to examine the effects of salinity stress on accumulation of chlorogenic acids in honeysuckle, through hydroponic experiments and field trials, and to examine the mechanisms underlying the effects. NaCl stress stimulated the transcription of genes encoding key enzymes in the synthesis of chlorogenic acids in leaves; accordingly, the concentrations of chlorogenic acids in leaves were significantly increased under NaCl stress, as was antioxidant activity. Specifically, the total concentration of leaf chlorogenic acids was increased by 145.74 and 50.34% after 30 days of 150 and 300 mM NaCl stress, respectively. Similarly, the concentrations of chlorogenic acids were higher in the leaves of plants in saline, compared with non-saline, plots, with increases in total concentrations of chlorogenic acids of 56.05 and 105.29% in October 2014 and 2015, respectively. Despite leaf biomass reduction, absolute amounts of chlorogenic acids per plant and phenylalanine ammonia-lyase (PAL) activity were significantly increased by soil salinity, confirming that the accumulation of chlorogenic acids in leaves was a result of stimulation of their synthesis under salinity stress. Soil salinity also led to elevated chlorogenic acid concentrations in honeysuckle flower buds, with significant increases in total chlorogenic acids concentration of 22.42 and 25.14% in May 2014 and 2015, respectively. Consistent with biomass reduction, the absolute amounts of chlorogenic acid per plant declined in flower buds of plants exposed to elevated soil salinity, with no significant change in PAL activity. Thus, salinity-induced chlorogenic acid accumulation in flower buds depended on an amplification effect of growth reduction. In conclusion, salinity stress improved the medicinal quality of

  13. Acid Sphingomyelinase Deficiency Prevents Diet-induced Hepatic Triacylglycerol Accumulation and Hyperglycemia in Mice*

    PubMed Central

    Deevska, Gergana M.; Rozenova, Krassimira A.; Giltiay, Natalia V.; Chambers, Melissa A.; White, James; Boyanovsky, Boris B.; Wei, Jia; Daugherty, Alan; Smart, Eric J.; Reid, Michael B.; Merrill, Alfred H.; Nikolova-Karakashian, Mariana

    2009-01-01

    Acid sphingomyelinase plays important roles in ceramide homeostasis, which has been proposed to be linked to insulin resistance. To test this association in vivo, acid sphingomyelinase deletion (asm–/–) was transferred to mice lacking the low density lipoprotein receptor (ldlr–/–), and then offsprings were placed on control or modified (enriched in saturated fat and cholesterol) diets for 10 weeks. The modified diet caused hypercholesterolemia in all genotypes; however, in contrast to asm+/+/ldlr–/–, the acid sphingomyelinase-deficient littermates did not display hepatic triacylglyceride accumulation, although sphingomyelin and other sphingolipids were substantially elevated, and the liver was enlarged. asm–/–/ldlr–/– mice on a modified diet did not accumulate body fat and were protected against diet-induced hyperglycemia and insulin resistance. Experiments with hepatocytes revealed that acid sphingomyelinase regulates the partitioning of the major fatty acid in the modified diet, palmitate, into two competitive and inversely related pools, triacylglycerides and sphingolipids, apparently via modulation of serine palmitoyltransferase, a rate-limiting enzyme in de novo sphingolipid synthesis. These studies provide evidence that acid sphingomyelinase activity plays an essential role in the regulation of glucose metabolism by regulating the hepatic accumulation of triacylglycerides and sphingolipids during consumption of a diet rich in saturated fats. PMID:19074137

  14. Changes in the physiological properties and kinetics of citric acid accumulation via carbon ion irradiation mutagenesis of Aspergillus niger *

    PubMed Central

    Hu, Wei; Chen, Ji-hong; Wang, Shu-yang; Liu, Jing; Song, Yuan; Wu, Qing-feng; Li, Wen-jian

    2016-01-01

    The objective of this work was to produce citric acid from corn starch using a newly isolated mutant of Aspergillus niger, and to analyze the relationship between changes in the physiological properties of A. niger induced by carbon ion irradiation and citric acid accumulation. Our results showed that the physiological characteristics of conidia in A. niger were closely related to citric acid accumulation and that lower growth rate and viability of conidia may be beneficial to citric acid accumulation. Using corn starch as a raw material, a high-yielding citric acid mutant, named HW2, was obtained. In a 10-L bioreactor, HW2 can accumulate 118.9 g/L citric acid with a residual total sugar concentration of only 14.4 g/L. This represented an 18% increase in citric acid accumulation and a 12.5% decrease in sugar utilization compared with the original strain.

  15. Sasa quelpaertensis and p-coumaric acid attenuate oleic acid-induced lipid accumulation in HepG2 cells.

    PubMed

    Kim, Jeong-Hwan; Kang, Seong-Il; Shin, Hye-Sun; Yoon, Seon-A; Kang, Seung-Woo; Ko, Hee-Chul; Kim, Se-Jae

    2013-01-01

    In this study, we examined the effects of Jeju dwarf bamboo (Sasa quelpaertensis Nakai) extract (JBE) and p-coumaric acid (CA) on oleic acid (OA)-induced lipid accumulation in HepG2 cells. JBE and CA increased the phosphorylation of AMP-activated protein kinase (AMPK), and acetyl-CoA carboxylase (ACC) and the expression of carnitine palmitoyl transferase 1a (CPT1a) in OA-treated HepG2 cells. Additionally, these compounds decreased sterol regulatory element-binding protein-1c (SREBP-1c), fatty acid synthase (FAS), and OA-induced lipid accumulation, suggesting that JBE and CA modulate lipid metabolism in HepG2 cells via the AMPK activation pathway.

  16. Rutin inhibits oleic acid induced lipid accumulation via reducing lipogenesis and oxidative stress in hepatocarcinoma cells.

    PubMed

    Wu, Cheng-Hsun; Lin, Ming-Cheng; Wang, Hsueh-Chun; Yang, Mon-Yuan; Jou, Ming-Jia; Wang, Chau-Jong

    2011-03-01

    Excessive lipid accumulation within liver has been proposed to cause obesity, hyperlipidemia, diabetes, and fatty liver disease. Rutin, a common dietary flavonoid that is consumed in fruits, vegetables, and plant-derived beverages, has various biological functions, including antioxidant, anti-inflammatory, and anticancer effects. However, a hypolipidemic effect of rutin on fatty liver disease has not been reported. In this study, we examined the effect of rutin on reducing lipid accumulation in hepatic cells. Hepatocytes were treated with oleic acid (OA) containing with or without rutin to observe the lipid accumulation by Nile red stain. The result showed rutin suppressed OA-induced lipid accumulation and increased adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) activity in hepatocytes. The expression of critical molecule involved in lipid synthesis, sterol regulatory element binding proteins-1 (SREBP-1), was attenuated in rutin-treated cells. Moreover, long-term incubation of rutin inhibited the transcriptions of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase (HMGCR), glycerol-3-phosphate acyltransferase (GPAT), fatty acid synthase (FAS), and acetyl-coenzyme carboxylase (ACC). Besides, we also found out the antioxidative effect of rutin by increasing the expression of peroxisome proliferator-activated receptor (PPAR)-α and antioxidative enzymes. Taken together, our findings suggest rutin could attenuate lipid accumulation by decreasing lipogenesis and oxidative stress in hepatocyte.

  17. Role of p53 in the cellular response following oleic acid accumulation in Chang liver cells.

    PubMed

    Park, Eun-Jung; Lee, Ah Young; Chang, Seung-Hee; Yu, Kyeong-Nam; Kim, Jae-Ho; Cho, Myung-Haing

    2014-01-03

    Abnormal accumulation of fatty acids triggers the harmful cellular response called lipotoxicity. In this study, we investigated the cellular response following accumulation of oleic acid (OA), a monounsaturated fatty acid, in human Chang liver cells. OA droplets were distributed freely in the cytoplasm and/or degraded within lysosomes. OA exposure increased ATP production and concomitantly dilated mitochondria. At 24h after OA exposure, cell viability decreased slightly and was coupled with a reduction in mitochondrial Ca(2+) concentration, the alteration in cell viability was also associated with the generation of reactive oxygen species and changes in the cell cycle. Moreover, OA treatment increased the expression of autophagy- and apoptotic cell death-related proteins in a dose-dependent manner. Furthermore, we investigated the role of p53, a tumor suppressor protein, in the cellular response elicited by OA accumulation. OA-induced changes in cell viability and ATP production were rescued to control levels when cells were pretreated with pifithrin-alpha (PTA), a p53 inhibitor. By contrast, the expressions of LC3-II and perilipin, proteins required for lipophagy, were down-regulated by PTA pretreatment. Taken together, our results suggest that p53 plays a key role in the cellular response elicited by OA accumulation in Chang liver cells.

  18. The TOC159 mutant of Arabidopsis thaliana accumulates altered levels of saturated and polyunsaturated fatty acids.

    PubMed

    Afitlhile, Meshack; Fry, Morgan; Workman, Samantha

    2015-02-01

    We evaluated whether the TOC159 mutant of Arabidopsis called plastid protein import 2-2 (ppi2-2) accumulates normal levels of fatty acids, and transcripts of fatty acid desaturases and galactolipid synthesis enzymes. The ppi2-2 mutant accumulates decreased pigments and total fatty acid content. The MGD1 gene was downregulated and the mutant accumulates decreased levels of monogalactosyldiacylglycerol (MGDG) and 16:3, which suggests that the prokaryotic pathway was impaired in the mutant. The HY5 gene, which encodes long hypocotyl5 transcription factor, was upregulated in the mutant. The DGD1 gene, an HY5 target was marginally increased and the mutant accumulates digalactosyldiacylglycerol at the control level. The mutant had increased expression of 3-ketoacyl-ACP synthase II gene, which encodes a plastid enzyme that elongates 16:0 to 18:0. Interestingly, glycerolipids in the mutant accumulate increased levels of 18:0. A gene that encodes stearoyl-ACP desaturase (SAD) was expressed at the control level and 18:1 was increased, which suggest that SAD may be strongly regulated at the posttranscriptional level. The molar ratio of MGDG to bilayer forming plastid lipids was decreased in the cold-acclimated wild type but not in the ppi2-2 mutant. This indicates that the mutant was unresponsive to cold-stress, and is consistent with increased levels of 18:0, and decreased 16:3 and 18:3 in the ppi2-2 mutant. Overall, these data indicate that a defective Toc159 receptor impaired the synthesis of MGDG, and affected desaturation of 16 and 18-carbon fatty acids. We conclude that expression of the MGD1 gene and synthesis of MGDG are tightly linked to plastid biogenesis.

  19. Increased SA in NPR1-silenced plants antagonizes JA and JA-dependent direct and indirect defenses in herbivore-attacked Nicotiana attenuata in nature.

    PubMed

    Rayapuram, Cbgowda; Baldwin, Ian T

    2007-11-01

    The phytohormone jasmonic acid (JA) is known to mediate herbivore resistance, while salicylic acid (SA) and non-expressor of PR-1 (NPR1) mediate pathogen resistance in many plants. Herbivore attack on Nicotiana attenuata elicits increases in JA and JA-mediated defenses, but also increases SA levels and Na-NPR1 transcripts from the plant's single genomic copy. SA treatment of wild-type plants increases Na-NPR1 and Na-PR1 transcripts. Plants silenced in NPR1 accumulation by RNAi (ir-npr1) are highly susceptible to herbivore and pathogen attack when planted in their native habitat in Utah. They are also impaired in their ability to attract Geocorus pallens predators, due to their decreased ability to release cis-alpha-bergamotene, a JA-elicited volatile 'alarm call'. In the glasshouse, Spodoptera exigua larvae grew better on ir-npr1 plants, which had low levels of JA, JA-isoleucine/leucine, lipoxygenase-3 (LOX3) transcripts and JA-elicited direct defense metabolites (nicotine, caffeoyl putrescine and rutin), but high levels of SA and isochorismate synthase (ICS) transcripts, suggesting de novo biosynthesis of SA. A microarray analysis revealed downregulation of many JA-elicited genes and upregulation of SA biosynthetic genes. JA treatment restored nicotine levels and resistance to S. exigua in ir-npr1 plants. We conclude that, during herbivore attack, NPR1 negatively regulates SA production, allowing the unfettered elicitation of JA-mediated defenses; when NPR1 is silenced, the elicited increases in SA production antagonize JA and JA-related defenses, making the plants susceptible to herbivores.

  20. Dynamics of phenolic acids and lignin accumulation in metal-treated Matricaria chamomilla roots.

    PubMed

    Kovácik, Jozef; Klejdus, Borivoj

    2008-03-01

    Phenylalanine ammonia-lyase (PAL) activity, 11 phenolic acids and lignin accumulation in Matricaria chamomilla roots exposed to low (3 microM) and high (60 and 120 microM) levels of cadmium (Cd) or copper (Cu) for 7 days were investigated. Five derivatives of cinnamic acid (chlorogenic, p-coumaric, caffeic, ferulic and sinapic acids) and six derivatives of benzoic acid (protocatechuic, vanillic, syringic, p-hydroxybenzoic, salicylic acids and protocatechuic aldehyde) were detected. Accumulation of glycoside-bound phenolics (revealed by acid hydrolysis) was enhanced mainly towards the end of the experiment, being more expressive in Cu-treated roots. Interestingly, chlorogenic acid was extremely elevated by the highest Cu dose (21-fold higher than control) suggesting its involvement in antioxidative protection. All compounds, with the exception of chlorogenic acid, were detected in the cell wall bound fraction, but only benzoic acids were found in the ester-bound fraction (revealed by alkaline hydrolysis). Soluble phenolics were present in substantially higher amounts in Cu-treated roots and more Cu was retained there in comparison to Cd. Cu strongly elevated PAL activity (by 5.4- and 12.1-fold in 60 and 120 microM treatment, respectively) and lignin content (by 71 and 148%, respectively) after one day of treatment, indicating formation of a barrier against metal entrance. Cd had slighter effects, supporting its non-redox active properties. Taken together, different forms of phenolic metabolites play an important role in chamomile tolerance to metal excess and participate in active antioxidative protection.

  1. Synthesis, structural characterization and biological activity of two diastereomeric JA-Ile macrolactones.

    PubMed

    Jimenez-Aleman, Guillermo H; Machado, Ricardo A R; Görls, Helmar; Baldwin, Ian T; Boland, Wilhelm

    2015-06-07

    Jasmonates are phytohormones involved in a wide range of plant processes, including growth, development, senescence, and defense. Jasmonoyl-L-isoleucine (JA-Ile, 2), an amino acid conjugate of jasmonic acid (JA, 1), has been identified as a bioactive endogenous jasmonate. However, JA-Ile (2) analogues trigger different responses in the plant. ω-Hydroxylation of the pentenyl side chain leads to the inactive 12-OH-JA-Ile (3) acting as a “stop” signal. On the other hand, a lactone derivative of 12-OH-JA (5) (jasmine ketolactone, JKL) occurs in nature, although with no known biological function. Inspired by the chemical structure of JKL (6) and in order to further explore the potential biological activities of 12-modified JA-Ile derivatives, we synthesized two macrolactones (JA-Ile-lactones (4a) and (4b)) derived from 12-OH-JA-Ile (3). The biological activity of (4a) and (4b) was tested for their ability to elicit nicotine production, a well-known jasmonate dependent secondary metabolite. Both macrolactones showed strong biological activity, inducing nicotine accumulation to a similar extent as methyl jasmonate does in Nicotiana attenuata leaves. Surprisingly, the highest nicotine contents were found in plants treated with the JA-Ile-lactone (4b), which has (3S,7S) configuration at the cyclopentanone not known from natural jasmonates. Macrolactone (4a) is a valuable standard to explore for its occurrence in nature.

  2. Kaempferol Isolated from Nelumbo nucifera Inhibits Lipid Accumulation and Increases Fatty Acid Oxidation Signaling in Adipocytes.

    PubMed

    Lee, Bonggi; Kwon, Misung; Choi, Jae Sue; Jeong, Hyoung Oh; Chung, Hae Young; Kim, Hyeung-Rak

    2015-12-01

    Stamens of Nelumbo nucifera Gaertn have been used as a Chinese medicine due to its antioxidant, hypoglycemic, and antiatherogenic activity. However, the effects of kaempferol, a main component of N. nucifera, on obesity are not fully understood. We examined the effect of kaempferol on adipogenesis and fatty acid oxidation signaling pathways in 3T3-L1 adipocytes. Kaempferol reduced cytoplasmic triglyceride (TG) accumulation in dose and time-dependent manners during adipocyte differentiation. Accumulation of TG was rapidly reversed by retrieving kaempferol treatment. Kaempferol broadly decreased mRNA or protein levels of adipogenic transcription factors and their target genes related to lipid accumulation. Kaempferol also suppressed glucose uptake and glucose transporter GLUT4 mRNA expression in adipocytes. Furthermore, protein docking simulation suggests that Kaempferol can directly bind to and activate peroxisome proliferator-activated receptor (PPAR)-α by forming hydrophobic interactions with VAL324, THR279, and LEU321 residues of PPARα. The binding affinity was higher than a well-known PPARα agonist fenofibrate. Consistently, mRNA expression levels of PPARα target genes were increased. Our study indicates while kaempferol inhibits lipogenic transcription factors and lipid accumulation, it may bind to PPARα and stimulate fatty acid oxidation signaling in adipocytes.

  3. Enhancement effect of ethanol on lipid and fatty acid accumulation and composition of Scenedesmus sp.

    PubMed

    Wu, Chengchen; Wang, Wei; Yue, Long; Yang, Zhen; Fu, Qiuguo; Ye, Qingfu

    2013-07-01

    The effects of ethanol concentration gradients along with varied cultivation times on lipid and fatty acid accumulation and composition of Scenedesmus sp. were studied. The maximum increment of algal density, lipid productivity, lipid content and fatty acid content were 6.61, 11.75, 1.34 and 3.14 times higher than the control group under 12h photoperiod. Algal light deprivation inhibited ethanol positive effects on algal growth and lipid biomass. The cumulative quantity of C16:0 and C18:0 decreased correspondingly with the increase of ethanol concentrations and cultivation times. Besides, unsaturated fatty acids appeared early in algal cells and increased 57.02% in maximum. However, only 2.27% (14)C was transferred from ethanol to fatty acids. The results indicated that adding proper amount of ethanol in algal culture medium was beneficial to biodiesel feedstock production and biodiesel properties.

  4. Modelling metal accumulation using humic acid as a surrogate for plant roots.

    PubMed

    Le, T T Yen; Swartjes, Frank; Römkens, Paul; Groenenberg, Jan E; Wang, Peng; Lofts, Stephen; Hendriks, A Jan

    2015-04-01

    Metal accumulation in roots was modelled with WHAM VII using humic acid (HA) as a surrogate for root surface. Metal accumulation was simulated as a function of computed metal binding to HA, with a correction term (E(HA)) to account for the differences in binding site density between HA and root surface. The approach was able to model metal accumulation in roots to within one order of magnitude for 95% of the data points. Total concentrations of Mn in roots of Vigna unguiculata, total concentrations of Ni, Zn, Cu and Cd in roots of Pisum sativum, as well as internalized concentrations of Cd, Ni, Pb and Zn in roots of Lolium perenne, were significantly correlated to the computed metal binding to HA. The method was less successful at modelling metal accumulation at low concentrations and in soil experiments. Measured concentrations of Cu internalized in L. perenne roots were not related to Cu binding to HA modelled and deviated from the predictions by over one order of magnitude. The results indicate that metal uptake by roots may under certain conditions be influenced by conditional physiological processes that cannot simulated by geochemical equilibrium. Processes occurring in chronic exposure of plants grown in soil to metals at low concentrations complicate the relationship between computed metal binding to HA and measured metal accumulation in roots.

  5. Competing mechanisms for perfluoroalkyl acid accumulation in plants revealed using an Arabidopsis model system.

    PubMed

    Müller, Claudia E; LeFevre, Gregory H; Timofte, Anca E; Hussain, Fatima A; Sattely, Elizabeth S; Luthy, Richard G

    2016-05-01

    Perfluoroalkyl acids (PFAAs) bioaccumulate in plants, presenting a human exposure route if present in irrigation water. Curiously, accumulation of PFAAs in plant tissues is greatest for both the short-chain and long-chain PFAAs, generating a U-shaped relationship with chain length. In the present study, the authors decouple competing mechanisms of PFAA accumulation using a hydroponic model plant system (Arabidopsis thaliana) exposed to a suite of 10 PFAAs to determine uptake, depuration, and translocation kinetics. Rapid saturation of root concentrations occurred for all PFAAs except perfluorobutanoate, the least-sorptive (shortest-chain) PFAA. Shoot concentrations increased continuously, indicating that PFAAs are efficiently transported and accumulate in shoots. Tissue concentrations of PFAAs during depuration rapidly declined in roots but remained constant in shoots, demonstrating irreversibility of the translocation process. Root and shoot concentration factors followed the U-shaped trend with perfluoroalkyl chain length; however, when normalized to dead-tissue sorption, this relationship linearized. The authors therefore introduce a novel term, the "sorption normalized concentration factor," to describe PFAA accumulation in plants; because of their hydrophobicity, sorption is the determining factor for long-chain PFAAs, whereas the shortest-chain PFAAs are most effectively transported in the plant. The present study provides a mechanistic explanation for previously unexplained PFAA accumulation trends in plants and suggests that shorter-chained PFAAs may bioaccumulate more readily in edible portions.

  6. Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China.

    PubMed

    Wu, Jianping; Liang, Guohua; Hui, Dafeng; Deng, Qi; Xiong, Xin; Qiu, Qingyan; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2016-02-15

    With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China.

  7. Formation and accumulation of alpha-acids, beta-acids, desmethylxanthohumol, and xanthohumol during flowering of hops (Humulus lupulus L.).

    PubMed

    De Keukeleire, Jelle; Ooms, Geert; Heyerick, Arne; Roldan-Ruiz, Isabel; Van Bockstaele, Erik; De Keukeleire, Denis

    2003-07-16

    Important secondary metabolites, present in hops (Humulus lupulus L.), include alpha-acids and beta-acids, which are essential for the brewing of beer, as well as the prenylated chalcones, desmethylxanthohumol, and xanthohumol, which exhibit interesting bioactive properties. Their formation and accumulation in five selected hop varieties, Wye Challenger, Wye Target, Golding, Admiral, and Whitbread Golding Variety, were quantitatively monitored by high-performance liquid chromatography using UV detection. All target compounds were present from the onset of flowering, not only in female hop cones but also in male inflorescences, albeit in low concentrations. During development from female inflorescences to cones, levels of alpha-acids, beta-acids, desmethylxanthohumol, and xanthohumol gradually increased, while each hop variety exhibited individual accumulation rates. Furthermore, these compounds were present in leaves of fully grown hops as well. The study demonstrated that key compounds for flavor and potential beneficial health effects associated with beer not only reside in the glandular lupulin structures but also are distributed over various parts of the hop plant.

  8. Supply of fatty acid is one limiting factor in the accumulation of triacylglycerol in developing embryos

    SciTech Connect

    Bao, X.; Ohlrogge, J.

    1999-08-01

    The metabolic factors that determine oil yield in seeds are still not well understood. To begin to examine the limits on triacylglycerol (TAG) production, developing Cuphea lanceolata, Ulmus carpinifolia, and Ulmus parvifolia embryos were incubated with factors whose availability might limit oil accumulation. The addition of glycerol or sucrose did not significantly influence the rate of TAG synthesis. However, the rate of {sup 14}C-TAG synthesis upon addition of 2.1 mM {sup 14}C-decanoic acid (10:0) was approximately four times higher than the in vivo rate of TAG accumulation in C. lanceolata and two times higher than the in vivo rate in U. carpinifolia and U. parvifolia. In C. lanceolata embryos, the highest rate of {sup 14}C-TAG synthesis (14.3 nmol h{sup {minus}1} embryo {sup {minus}1}) was achieved with the addition of 3.6 mM decanoic acid. {sup 14}C-Decanoic acid was incorporated equally well in all three acyl positions of TAG. The results suggest that C. lancelata, U. Carpinifolia, and U. parvifolia embryos have sufficient acyltransferase activities and glycerol-3-phosphate levels to support rates of TAG synthesis in excess of those found in vivo. Consequently, the amount of TAG synthesized in these oilseeds may be in part determined by the amount of fatty acid produced in plastids.

  9. Osmotic Stress-Induced Polyamine Accumulation in Cereal Leaves : II. Relation to Amino Acid Pools.

    PubMed

    Flores, H E; Galston, A W

    1984-05-01

    Arginine decarboxylase activity increases 2- to 3-fold in osmotically stressed oat leaves in both light and dark, but putrescine accumulation in the dark is only one-third to one-half of that in light-stressed leaves. If arginine or ornithine are supplied to dark-stressed leaves, putrescine rises to levels comparable to those obtained by incubation under light. Thus, precursor amino acid availability is limiting to the stress response. Amino acid levels change rapidly upon osmotic treatment; notably, glutamic acid decreases with a corresponding rise in glutamine. Difluoromethylarginine (0.01-0.1 millimolar), the enzyme-activated irreversible inhibitor of arginine decarboxylase, prevents the stress-induced putrescine rise, as well as the incorporation of label from [(14)C]arginine, with the expected accumulation of free arginine, but has no effect on the rest of the amino acid pool. The use of specific inhibitors such as alpha-difluoromethylarginine is suggested as probes for the physiological significance of stress responses by plant cells.

  10. Ascorbic acid reduces accumulation of (/sup 3/H)spiperone in mouse striatum in vivo

    SciTech Connect

    Dorris, R.L.

    1987-10-01

    (/sup 3/H)Spiperone was administered to mice. In agreement with other published reports, 2 hr later the accumulation of tritium was three to four times greater in the corpus striatum than in the cerebellum. Ascorbic acid (100, 1000, 2000 mg/kg, ip, 30 min) reduced the 2-hr accumulation in the corpus striatum 16, 42, and 63%, respectively, with only the highest does producing any significant reduction in the cerebellum. The effect was still evident in striatum 18 hr after a single dose of 1000 mg/kg. Striatal minces taken from mice treated 1 or 2 hr earlier with ascorbic acid showed no reduction in (/sup 3/H)spiperone binding. However, preincubation of striatal minces for 2 hr with ascorbic acid (10/sup -3/ M) produced an 82% reduction in specific binding while not having any effect on nonspecific binding. While it cannot be certain that the reduction of striatal (/sup 3/H) spiperone concentrations after ascorbic acid in vivo was not a result of some nonspecific alteration in the pharmacokinetics of (/sup 3/H)spiperone, the in vitro observation strongly suggests that it resulted from an alteration of binding characteristics at the receptor level.

  11. Abscisic Acid accumulation in spinach leaf slices in the presence of penetrating and nonpenetrating solutes.

    PubMed

    Creelman, R A; Zeevaart, J A

    1985-01-01

    Abscisic acid (ABA) accumulated in detached, wilted leaves of spinach (Spinacia oleracea L. cv Savoy Hybrid 612) and reached a maximum level within 3 to 4 hours. The increase in ABA over that found in detached turgid leaves was approximately 10-fold. The effects of water stress could be mimicked by the use of thin slices of spinach leaves incubated in the presence of 0.6 molar mannitol, a compound which causes plasmolysis (loss of turgor). About equal amounts of ABA were found both in the leaf slices and in detached leaves, whereas 2 to 4 times more ABA accumulated in the medium than in the slices. When spinach leaf slices were incubated with ethylene glycol, a compound which rapidly penetrates the cell membrane causing a decrease in the osmotic potential of the tissue and only transient loss of turgor, no ABA accumulated. Ethylene glycol was not inhibitory with respect to ABA accumulation. Spinach leaf slices incubated in both ethylene glycol and mannitol had ABA levels similar to those found when slices were incubated with mannitol alone. Increases similar to those found with mannitol also occurred when Aquacide III, a highly purified form of polyethylene glycol, was used. Aquacide III causes cytorrhysis, a situation similar to that found in wilted leaves. Thus, it appears that loss of turgor is essential for ABA accumulation.When spinach leaf slices were incubated with solutes which are supposed to disturb membrane integrity (KHSO(3), 2-propanol, or KCl) no increase in ABA was observed. These data indicate that, with respect to the accumulation of ABA, mannitol caused a physical stress (loss of turgor) rather than a chemical stress (membrane damage).

  12. Low accumulation of chlorogenic acids represses reddening during flesh browning in Japanese peach "Okayama PEH7".

    PubMed

    Yokotani, Naoki; Uraji, Misugi; Hara, Miyuki; Hihara, Seisuke; Hatanaka, Tadashi; Oda, Kenji

    2017-01-01

    In peaches, fruit flesh browns unattractively after peeling or cutting. A recently developed cultivar, Okayama PEH7, was distinct from other Japanese cultivars, including Okayama PEH8, with respect to its reduced browning potential. Homogenate prepared from Okayama PEH7 flesh had significantly less reddening during the browning reaction. Okayama PEH7 had less soluble phenolic compounds and higher polyphenol oxidase activity than Okayama PEH8. Reduced browning was observed even when phenols prepared from Okayama PEH7 were incubated with crude extract from Okayama PEH8, suggesting that phenols lower the browning potential of Okayama PEH7. In Okayama PEH7, contents of chlorogenic acid and its isomers were about one-tenth compared to Okayama PEH8. Exogenous addition of chlorogenic acid to Okayama PEH7 homogenate increased the browning potential and visibly enhanced reddening. These results indicate that the reduced browning of Okayama PEH7 flesh is due to a defect in chlorogenic acid accumulation.

  13. Improved cadmium uptake and accumulation in the hyperaccumulator Sedum alfredii: the impact of citric acid and tartaric acid* #

    PubMed Central

    Lu, Ling-li; Tian, Sheng-ke; Yang, Xiao-e; Peng, Hong-yun; Li, Ting-qiang

    2013-01-01

    The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils. Organic acid has been suggested to be involved in toxic metallic element tolerance, translocation, and accumulation in plants. The impact of exogenous organic acids on cadmium (Cd) uptake and translocation in the zinc (Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study. By the addition of organic acids, short-term (2 h) root uptake of 109Cd increased significantly, and higher 109Cd contents in roots and shoots were noted 24 h after uptake, when compared to controls. About 85% of the 109Cd taken up was distributed to the shoots in plants with citric acid (CA) treatments, as compared with 75% within controls. No such effect was observed for tartaric acid (TA). Reduced growth under Cd stress was significantly alleviated by low CA. Long-term application of the two organic acids both resulted in elevated Cd in plants, but the effects varied with exposure time and levels. The results imply that CA may be involved in the processes of Cd uptake, translocation and tolerance in S. alfredii, whereas the impact of TA is mainly on the root uptake of Cd. PMID:23365009

  14. Arsenate and arsenite exposure modulate antioxidants and amino acids in contrasting arsenic accumulating rice (Oryza sativa L.) genotypes.

    PubMed

    Dave, Richa; Tripathi, Rudra Deo; Dwivedi, Sanjay; Tripathi, Preeti; Dixit, Garima; Sharma, Yogesh Kumar; Trivedi, Prabodh Kumar; Corpas, Francisco J; Barroso, Juan B; Chakrabarty, Debasis

    2013-11-15

    Carcinogenic arsenic (As) concentrations are found in rice due to irrigation with contaminated groundwater in South-East Asia. The present study evaluates comparative antioxidant property and specific amino acid accumulation in contrasting rice genotypes corresponding to differential As accumulation during arsenate (As(V)) and arsenite (As(III)) exposures. The study was conducted on two contrasting As accumulating rice genotypes selected from 303 genotype accessions, in hydroponic conditions. Maximum As accumulation was up to 1181 μg g(-1) dw in the roots of high As accumulating genotype (HARG), and 89 μg g(-1) dw in low As accumulating genotype (LARG) under As(III) exposures. The inorganic As was correlated more significantly upon exposures to As(III) than As(V). In the presence of As(V) various antioxidant enzymes guiacol peroxidase (GPX), ascorbate peroxidase (APX) and superoxide dismutase (SOD) were highly stimulated in HARG. The stress responsive amino acids proline, cysteine, glycine, glutamic acid and methionine showed higher accumulation in HARG than LARG. A clear correlation was found between stress responsive amino acids, As accumulation and antioxidative response. The comparisons between the contrasting genotypes helped to determine the significance of antioxidants and specific amino acid response to As stress.

  15. A large-scale genetic screen for mutants with altered salicylic acid accumulation in Arabidopsis.

    PubMed

    Ding, Yezhang; Shaholli, Danjela; Mou, Zhonglin

    2014-01-01

    Salicylic acid (SA) is a key defense signal molecule against biotrophic and hemibiotrophic pathogens in plants, but how SA is synthesized in plant cells still remains elusive. Identification of new components involved in pathogen-induced SA accumulation would help address this question. To this end, we performed a large-scale genetic screen for mutants with altered SA accumulation during pathogen infection in Arabidopsis using a bacterial biosensor Acinetobacter sp. ADPWH_lux-based SA quantification method. A total of 35,000 M2 plants in the npr1-3 mutant background have been individually analyzed for the bacterial pathogen Pseudomonas syringae pv. maculicola (Psm) ES4326-induced SA accumulation. Among the mutants isolated, 19 had SA levels lower than npr1 (sln) and two exhibited increased SA accumulation in npr1 (isn). Complementation tests revealed that seven of the sln mutants are new alleles of eds5/sid1, two are sid2/eds16 alleles, one is allelic to pad4, and the remaining seven sln and two isn mutants are new non-allelic SA accumulation mutants. Interestingly, a large group of mutants (in the npr1-3 background), in which Psm ES4326-induced SA levels were similar to those in the wild-type Columbia plants, were identified, suggesting that the signaling network fine-tuning pathogen-induced SA accumulation is complex. We further characterized the sln1 single mutant and found that Psm ES4326-induced defense responses were compromised in this mutant. These defense response defects could be rescued by exogenous SA, suggesting that SLN1 functions upstream of SA. The sln1 mutation was mapped to a region on the north arm of chromosome I, which contains no known genes regulating pathogen-induced SA accumulation, indicating that SLN1 likely encodes a new regulator of SA biosynthesis. Thus, the new sln and isn mutants identified in this genetic screen are valuable for dissecting the molecular mechanisms underlying pathogen-induced SA accumulation in plants.

  16. A strategy for promoting astaxanthin accumulation in Haematococcus pluvialis by 1-aminocyclopropane-1-carboxylic acid application.

    PubMed

    Lee, Changsu; Choi, Yoon-E; Yun, Yeoung-Sang

    2016-10-20

    The green algae Haematococcus pluvialis is a freshwater unicellular microalga belonging to Chlorophyceae. It is one of the best natural sources of astaxanthin, a secondary metabolite commonly used as an antioxidant and anti-inflammatory agent. Due to the importance of astaxanthin, various efforts have been made to increase its production. In this study, we attempted to develop a strategy for promoting astaxanthin accumulation in H. pluvialis using 1-aminocyclopropane-1-carboxylic acid (ACC), a precursor of ethylene (normally known as an aging hormone in plants). Our results demonstrated that ACC could enhance the growth of H. pluvialis, thereby promoting astaxanthin accumulation. Therefore, ACC has an indirect influence on astaxanthin production. We further verified the effect of ACC with a direct treatment of ethylene originated from banana peels. These results indicate that ethylene could be applied as an indirect method for enhancing growth and astaxanthin biosynthesis in H. pluvialis.

  17. Microencapsulation of okadaic acid as a tool for studying the accumulation of DSP toxins in mussels.

    PubMed

    Rossignoli, Araceli E; Fernández, David; Acosta, Carmen P; Blanco, Juan

    2011-02-01

    The possibility and effectiveness of microencapsulation of okadaic acid (OA) in gelatin-acacia microcapsules has been studied. The encapsulation efficiency was higher than 33%. The microcapsules were shown to be very stable, not leaching more than 9% of the encapsulated OA in a 20-h period. OA from the microcapsules was absorbed by the mussels very efficiently, accumulating--after 3 days of feeding and one of depuration--65% of the OA in microcapsules and 22% of the total OA used at the beginning of the microencapsulation process. These efficiencies and the possibility of encapsulating single DSP toxins and derivatives constitute a valuable tool for the study of the accumulation and biotransformation of DSP toxins in bivalves.

  18. Electrochemical antimony removal from accumulator acid: results from removal trials in laboratory cells.

    PubMed

    Bergmann, M E Henry; Koparal, A Savas

    2011-11-30

    Regeneration of spent accumulator acid could be an alternative process for crystallization, neutralisation and disposal. Therefore, for the first time in a study of the possibilities of electrochemical removal of antimony and accumulator acid regeneration on a laboratory scale, two synthetic and several real systems containing sulfuric acid of concentrations ranging between 28% and 36%, and antimony species were tested. Discontinuous electrochemical reactors with anion exchange membranes were successfully used in these experiments, which were conducted at a temperature of 35°C. Removal of antimony using cells that were not divided by a separator, however, was not possible. In selected experiments, by varying the electrode material, type of electrolyte, and cell current, the concentration of antimony could be reduced from the range of 5 ppm to 0.15 ppm. This resulted in current efficiencies between 0.00002% and 0.001%, and in specific electroenergy demands between 100 Wh L(-1) and 2000 Wh L(-1). In other experiments on substances with antimony contents up to 3500 mg L(-1), the current efficiencies obtained were more than a thousandfold higher. In contrast to the formally high relative energy consumption parameters absolute demand parameters are relatively small and favour the electrochemical method in small scale application. Besides plate electrodes, 3D-cathodes were used. Copper- and graphite cathodes produced the best results.

  19. Light avoidance reduces ascorbic acid accumulation in the peel of Citrus fruit.

    PubMed

    Lado, Joanna; Alós, Enriqueta; Rodrigo, María Jesús; Zacarías, Lorenzo

    2015-02-01

    Citrus fruits are highly consumed worldwide and represent one of the most important sources of ascorbic acid (AsA). However, information about the molecular mechanisms regulating AsA accumulation in Citrus fruit and the effects of environmental factors is scarce. In this study we have investigated the effect of fruit shading on AsA content and the expression of AsA biosynthetic, degrading and recycling genes in fruits of different Citrus species. Immature-green fruits were covered at the end of the cell enlargement phase and AsA concentration in the flavedo declined and remained at low levels as compared with light-exposed fruits. Fruit shading marginally altered the expression of genes from the l-galactose pathway and this effect was variable in the four Citrus species. However, specific isoforms (GalUR8 or GalUR12) from the l-galacturonic acid pathway were significantly repressed paralleling the reduction in AsA concentration. No significant effect of shading was detected in transcription of genes of the myo-inositol and l-gulose pathways as well as recycling and degradation. Collectively, results indicate that light avoidance inhibited accumulation of AsA in the flavedo of Citrus fruits and suggest that the l-galacturonic acid pathway has a relevant contribution to AsA content in this tissue.

  20. Influence of Indole-3-Acetic Acid and Gibberellic Acid on Phenylpropanoid Accumulation in Common Buckwheat (Fagopyrum esculentum Moench) Sprouts.

    PubMed

    Park, Chang Ha; Yeo, Hyeon Ji; Park, Yun Ji; Morgan, Abubaker M A; Valan Arasu, Mariadhas; Al-Dhabi, Naif Abdullah; Park, Sang Un

    2017-02-28

    We investigated the effects of natural plant hormones, indole-3-acetic (IAA) acid and gibberellic acid (GA), on the growth parameters and production of flavonoids and other phenolic compounds in common buckwheat sprouts. A total of 17 phenolic compounds were identified using liquid chromatography-mass spectrometry (LC-MS) analysis. Among these, seven compounds (4-hydroxybenzoic acid, catechin, chlorogenic acid, caffeic acid, epicatechin, rutin, and quercetin) were quantified by high-performance liquid chromatography (HPLC) after treating the common buckwheat sprouts with different concentrations of the hormones IAA and GA. At a concentration of 0.5 mg/L, both IAA and GA exhibited the highest levels of growth parameters (shoot length, root length, and fresh weight). The HPLC analysis showed that the treatment of sprouts with IAA at concentrations ranging from 0.1 to 1.0 mg/L produced higher or comparable levels of the total phenolic compounds than the control sprout and enhanced the production of rutin. Similarly, the supplementation with 0.1 and 0.5 mg/L GA increased the content of rutin in buckwheat sprouts. Our results suggested that the treatment with optimal concentrations of IAA and GA enhanced the growth parameters and accumulation of flavonoids and other phenolic compounds in buckwheat sprouts.

  1. Comparative proteomic analysis of engineered Saccharomyces cerevisiae with enhanced free fatty acid accumulation.

    PubMed

    Chen, Liwei; Lee, Jaslyn Jie Lin; Zhang, Jianhua; Chen, Wei Ning

    2016-02-01

    The engineered Saccharomyces cerevisiae strain △faa1△faa4 [Acot5s] was demonstrated to accumulate more free fatty acids (FFA) previously. Here, comparative proteomic analysis was performed to get a global overview of metabolic regulation in the strain. Over 500 proteins were identified, and 82 of those proteins were found to change significantly in the engineered strains. Proteins involved in glycolysis, acetate metabolism, fatty acid synthesis, TCA cycle, glyoxylate cycle, the pentose phosphate pathway, respiration, transportation, and stress response were found to be upregulated in △faa1△faa4 [Acot5s] as compared to the wild type. On the other hand, proteins involved in glycerol, ethanol, ergosterol, and cell wall synthesis were downregulated. Taken together with our metabolite analysis, our results showed that the disruption of Faa1 and Faa4 and expression of Acot5s in the engineered strain △faa1△faa4 [Acot5s] not only relieved the feedback inhibition of fatty acyl-CoAs on fatty acid synthesis, but also caused a major metabolic rearrangement. The rearrangement redirected carbon flux toward the pathways which generate the essential substrates and cofactors for fatty acid synthesis, such as acetyl-CoA, ATP, and NADPH. Therefore, our results help shed light on the mechanism for the increased production of fatty acids in the engineered strains, which is useful in providing information for future studies in biofuel production.

  2. Mononuclear phagocyte accumulates a stearic acid derivative during differentiation into macrophages. Effects of stearic acid on macrophage differentiation and Mycobacterium tuberculosis control.

    PubMed

    Mosquera-Restrepo, Sergio Fabián; Caro, Ana Cecilia; Peláez-Jaramillo, Carlos Alberto; Rojas, Mauricio

    2016-05-01

    The fatty acid composition of monocytes changes substantially during differentiation into macrophages, increasing the proportion of saturated fatty acids. These changes prompted us to investigate whether fatty acid accumulation in the extracellular milieu could affect the differentiation of bystander mononuclear phagocytes. An esterified fatty acid derivative, stearate, was the only fatty acid that significantly increased in macrophage supernatants, and there were higher levels when cells differentiated in the presence of Mycobacterium tuberculosis H37Rv or purified protein derivative (PPD). Exogenous stearic acid enhanced the expression of HLA-DR and CD64; there was also accumulation of IL-12, TNF-α, IL-6, MIP-1 α and β and a reduction in MCP-1 and the bacterial load. These results suggested that during differentiation, a derivative of stearic acid, which promotes the process as well as the effector mechanisms of phagocytes against the mycobacterium, accumulates in the cell supernatants.

  3. Effect of the treatment by slightly acidic electrolyzed water on the accumulation of γ-aminobutyric acid in germinated brown millet.

    PubMed

    Li, Xingfeng; Hao, Jianxiong; Liu, Xianggui; Liu, Haijie; Ning, Yawei; Cheng, Ruhong; Tan, Bin; Jia, Yingmin

    2015-11-01

    The accumulation of γ-aminobutyric acid and the microbial decontamination are concerned increasingly in the production of sprouts. In this work, the effect of the treatment by slightly acidic electrolyzed water on the accumulation of γ-aminobutyric acid in the germinated brown millet was evaluated by high performance liquid chromatography during germination. The results showed that slightly acidic electrolyzed water with appropriate available chlorine (15 or 30 mg/L) could promote the accumulation of γ-aminobutyric acid by up to 21% (P < 0.05). However, the treatment with slightly acidic electrolyzed water could not enhance the sprouts growth of the germinated brown millet. The catalase and peroxidase activities of the germinated brown millet during germination were in agreement with the sprouts growth. Our results suggested that the accumulation of γ-aminobutyric acid was independent of the length of sprouts in germinated grains. Moreover, the treatment with slightly acidic electrolyzed water significantly reduced the microbial counts in the germinated millet (P < 0.05) and the treatment with high available chlorine concentration (15 and 30 mg/L) showed stronger anti-infection potential in the germinated brown millet than that of lower available chlorine concentration (5 mg/L). In conclusion, the treatment with slightly acidic electrolyzed water is an available approach to improve the accumulation of γ-aminobutyric acid and anti-infection potential in the germinated brown millet, and it can avoid too long millet sprouts.

  4. [Accumulation of amino acid substitutions promotes irreversible structural changes in the hemagglutinin of human influenza AH3 virus during evolution].

    PubMed

    Nakajima, Katsuhisa; Nobusawa, Eri; Nakajima, Setsuko

    2006-06-01

    During protein evolution the amino acid substitutions accumulate with time. However, the effect of accumulation of the amino acid substitutions to structural changes has not been estimated well. We will propose that the discordance of amino acid substitution on the HA protein of influenza A virus is useful for the assessment of structural changes during evolution. Discordance value can be obtained from the experimental data of tolerance or intolerance by introducing site directed mutagenesis at the homologous positions of two HA proteins holding the same amino acid residues. The value of discordance correlated to the number of amino acid differences among proteins. In the H3HA discordance rate was calculated to be 0.45% per one amino acid change. Furthermore, discordance of amino acid substitutions suggests that tolerable amino acid substitutions in different order have a probability of promoting irreversible divergence of the HA protein to different subtypes.

  5. Accumulation of seleno-amino acids in legume and grass plant species grown in selenium-laden soils

    SciTech Connect

    Wu, L.; Guo, X.; Banuelos, G.S.

    1997-03-01

    Seleno-amino acid accumulation was studied for two legume and two grass species grown in Selenium (Se)-laden soils. An antagonistic relationship was found between the tissue Se-amino acid concentration and the corresponding sulfur-amino acid concentration. This relationship demonstrates a competitive interaction between Se and sulfate at the amino acid synthesis level. The nonsulfur-containing amino acids were not substantially affected by the increase of tissue Se concentration. Sour clover (Melilotus indica L.) was able to accumulate much greater tissue Se concentration than the other three species. Tissue methionine concentration of sour clover, rabbitfoot grass (Polypogon monspeliensis L.), and tall fescue (Festuca arundinacea Schreb.) was not significantly affected by the increase of tissue selenomethionine concentration, but a highly significant negative correlation was found in alfalfa (Medicago sativa L.). This discrepancy suggests that a less antagonistic effect on sulfur-amino acids under the increase of Se-amino acid analogues in the tissue might be able to minimize Se toxicity to the plant. Both Se-methylselenocysteine (nonprotein amino acid) and selenomethionine (protein amino acid) accumulated in the plants when grown in Se-laden soils. Possible effects of these Se-amino acids accumulated by plants on animal health should be tested before the plants are used for forage supplementation.

  6. Accumulation of Flavonols over Hydroxycinnamic Acids Favors Oxidative Damage Protection under Abiotic Stress

    PubMed Central

    Martinez, Vicente; Mestre, Teresa C.; Rubio, Francisco; Girones-Vilaplana, Amadeo; Moreno, Diego A.; Mittler, Ron; Rivero, Rosa M.

    2016-01-01

    Efficient detoxification of reactive oxygen species (ROS) is thought to play a key role in enhancing the tolerance of plants to abiotic stresses. Although multiple pathways, enzymes, and antioxidants are present in plants, their exact roles during different stress responses remain unclear. Here, we report on the characterization of the different antioxidant mechanisms of tomato plants subjected to heat stress, salinity stress, or a combination of both stresses. All the treatments applied induced an increase of oxidative stress, with the salinity treatment being the most aggressive, resulting in plants with the lowest biomass, and the highest levels of H2O2 accumulation, lipid peroxidation, and protein oxidation. However, the results obtained from the transcript expression study and enzymatic activities related to the ascorbate-glutathione pathway did not fully explain the differences in the oxidative damage observed between salinity and the combination of salinity and heat. An exhaustive metabolomics study revealed the differential accumulation of phenolic compounds depending on the type of abiotic stress applied. An analysis at gene and enzyme levels of the phenylpropanoid metabolism concluded that under conditions where flavonols accumulated to a greater degree as compared to hydroxycinnamic acids, the oxidative damage was lower, highlighting the importance of flavonols as powerful antioxidants, and their role in abiotic stress tolerance. PMID:27379130

  7. Atherosclerotic Lesion Progression Changes Lysophosphatidic Acid Homeostasis to Favor its Accumulation

    PubMed Central

    Bot, Martine; Bot, Ilze; Lopez-Vales, Rubén; van de Lest, Chris H.A.; Saulnier-Blache, Jean Sébastien; Helms, J. Bernd; David, Samuel; van Berkel, Theo J.C.; Biessen, Erik A.L.

    2010-01-01

    Lysophosphatidic acid (LPA) accumulates in the central atheroma of human atherosclerotic plaques and is the primary platelet-activating lipid constituent of plaques. Here, we investigated the enzymatic regulation of LPA homeostasis in atherosclerotic lesions at various stages of disease progression. Atherosclerotic lesions were induced in carotid arteries of low-density lipoprotein receptor–deficient mice by semiconstrictive collar placement. At 2-week intervals after collar placement, lipids and RNA were extracted from the vessel segments carrying the plaque. Enzymatic-and liquid chromatography-mass spectrometry–based lipid profiling revealed progressive accumulation of LPA species in atherosclerotic tissue preceded by an increase in lysophosphatidylcholine, a precursor in LPA synthesis. Plaque expression of LPA-generating enzymes cytoplasmic phospholipase A2IVA (cPLA2IVA) and calcium-independent PLA2VIA (iPLA2VIA) was gradually increased, whereas that of the LPA-hydrolyzing enzyme LPA acyltransferase α was quenched. Increased expression of cPLA2IVA and iPLA2VIA in advanced lesions was confirmed by immunohistochemistry. Moreover, LPA receptors 1 and 2 were 50% decreased and sevenfold upregulated, respectively. Therefore, key proteins in LPA homeostasis are increasingly dysregulated in the plaque during atherogenesis, favoring intracellular LPA production. This might at least partly explain the observed progressive accumulation of this thrombogenic proinflammatory lipid in human and mouse plaques. Thus, intervention in the enzymatic LPA production may be an attractive measure to lower intraplaque LPA content, thereby reducing plaque progression and thrombogenicity. PMID:20431029

  8. Accumulation of Flavonols over Hydroxycinnamic Acids Favors Oxidative Damage Protection under Abiotic Stress.

    PubMed

    Martinez, Vicente; Mestre, Teresa C; Rubio, Francisco; Girones-Vilaplana, Amadeo; Moreno, Diego A; Mittler, Ron; Rivero, Rosa M

    2016-01-01

    Efficient detoxification of reactive oxygen species (ROS) is thought to play a key role in enhancing the tolerance of plants to abiotic stresses. Although multiple pathways, enzymes, and antioxidants are present in plants, their exact roles during different stress responses remain unclear. Here, we report on the characterization of the different antioxidant mechanisms of tomato plants subjected to heat stress, salinity stress, or a combination of both stresses. All the treatments applied induced an increase of oxidative stress, with the salinity treatment being the most aggressive, resulting in plants with the lowest biomass, and the highest levels of H2O2 accumulation, lipid peroxidation, and protein oxidation. However, the results obtained from the transcript expression study and enzymatic activities related to the ascorbate-glutathione pathway did not fully explain the differences in the oxidative damage observed between salinity and the combination of salinity and heat. An exhaustive metabolomics study revealed the differential accumulation of phenolic compounds depending on the type of abiotic stress applied. An analysis at gene and enzyme levels of the phenylpropanoid metabolism concluded that under conditions where flavonols accumulated to a greater degree as compared to hydroxycinnamic acids, the oxidative damage was lower, highlighting the importance of flavonols as powerful antioxidants, and their role in abiotic stress tolerance.

  9. Vermicompost humic acids modulate the accumulation and metabolism of ROS in rice plants.

    PubMed

    García, Andrés Calderín; Santos, Leandro Azevedo; de Souza, Luiz Gilberto Ambrósio; Tavares, Orlando Carlos Huertas; Zonta, Everaldo; Gomes, Ernane Tarcisio Martins; García-Mina, José Maria; Berbara, Ricardo Luis Louro

    2016-03-15

    This work aims to determine the reactive oxygen species (ROS) accumulation, gene expression, anti-oxidant enzyme activity, and derived effects on membrane lipid peroxidation and certain stress markers (proline and malondialdehyde-MDA) in the roots of unstressed and PEG-stressed rice plants associated with vermicompost humic acid (VCHA) application. The results show that the application of VCHA to the roots of unstressed rice plants caused a slight but significant increase in root ROS accumulation and the gene expression and activity of the major anti-oxidant enzymes (superoxide dismutase and peroxidase). This action did not have negative effects on root development, and an increase in both root growth and root proliferation occurred. However, the root proline and MDA concentrations and the root permeability results indicate the development of a type of mild stress associated with VCHA application. When VCHA was applied to PEG-stressed plants, a clear alleviation of the inhibition in root development linked to PEG-mediated osmotic stress was observed. This was associated with a reduction in root ROS production and anti-oxidant enzymatic activity caused by osmotic stress. This alleviation of stress caused by VCHA was also reflected as a reduction in the PEG-mediated concentration of MDA in the root as well as root permeability. In summary, the beneficial action of VCHA on the root development of unstressed or PEG-stressed rice plants clearly involves the modulation of ROS accumulation in roots.

  10. Abscisic acid accumulation in spinach leaf slices in the presence of penetrating and nonpenetrating solutes

    SciTech Connect

    Creelman, R.A.; Zeevaart, J.A.D.

    1985-01-01

    Abscisic acid (ABA) accumulated in detached, wilted leaves of spinach (Spinacia oleracea L. cv Savoy Hybrid 612) and reached a maximum level within 3 to 4 hours. The increase in ABA over that found in detached turgid leaves was approximately 10-fold. The effects of water stress could be mimicked by the use of thin slices of spinach leaves incubated in the presence of 0.6 molar mannitol, a compound which causes plasmolysis (loss of turgor). When spinach leaf slices were incubated with ethylene glycol, a compound which rapidly penetrates the cell membrane causing a decrease in the osmotic potential of the tissue and only transient loss of turgor, no ABA accumulated. Spinach leaf slices incubated in both ethylene glycol and mannitol had ABA levels similar to those found when slices were incubated with mannitol alone. Increases similar to those found with mannitol also occurred when Aquacide III, a highly purified form of polyethylene glycol, was used. When spinach leaf slices were incubated with solutes which are supposed to disturb membrane integrity no increase in ABA was observed. These data indicate that, with respect to the accumulation of ABA, mannitol caused a physical stress rather than a chemical stress.

  11. Accumulation of polyhydroxyalkanoate from styrene and phenylacetic acid by Pseudomonas putida CA-3.

    PubMed

    Ward, Patrick G; de Roo, Guy; O'Connor, Kevin E

    2005-04-01

    Pseudomonas putida CA-3 is capable of converting the aromatic hydrocarbon styrene, its metabolite phenylacetic acid, and glucose into polyhydroxyalkanoate (PHA) when a limiting concentration of nitrogen (as sodium ammonium phosphate) is supplied to the growth medium. PHA accumulation occurs to a low level when the nitrogen concentration drops below 26.8 mg/liter and increases rapidly once the nitrogen is no longer detectable in the growth medium. The depletion of nitrogen and the onset of PHA accumulation coincided with a decrease in the rate of substrate utilization and biochemical activity of whole cells grown on styrene, phenylacetic acid, and glucose. However, the efficiency of carbon conversion to PHA dramatically increased once the nitrogen concentration dropped below 26.8 mg/liter in the growth medium. When supplied with 67 mg of nitrogen/liter, the carbon-to-nitrogen (C:N) ratios that result in a maximum yield of PHA (grams of PHA per gram of carbon) for styrene, phenylacetic acid, and glucose are 28:1, 21:1, and 18:1, respectively. In cells grown on styrene and phenylacetic acid, decreasing the carbon-to-nitrogen ratio below 28:1 and 21:1, respectively, by increasing the nitrogen concentration and using a fixed carbon concentration leads to lower levels of PHA per cell and lower levels of PHA per batch of cells. Increasing the carbon-to-nitrogen ratio above 28:1 and 21:1 for cells grown on styrene and phenylacetic acid, respectively, by decreasing the nitrogen concentration and using a fixed carbon concentration increases the level of PHA per cell but results in a lower level of PHA per batch of cells. Increasing the carbon and nitrogen concentrations but maintaining the carbon-to-nitrogen ratio of 28:1 and 21:1 for cells grown on styrene and phenylacetic acid, respectively, results in an increase in the total PHA per batch of cells. The maximum yields for PHA from styrene, phenylacetic acid, and glucose are 0.11, 0.17, and 0.22 g of PHA per g of carbon

  12. Intraneuronal amyloid beta accumulation and oxidative damage to nucleic acids in Alzheimer disease.

    PubMed

    Nunomura, Akihiko; Tamaoki, Toshio; Tanaka, Koich; Motohashi, Nobutaka; Nakamura, Masao; Hayashi, Takaaki; Yamaguchi, Haruyasu; Shimohama, Shun; Lee, Hyoung-gon; Zhu, Xiongwei; Smith, Mark A; Perry, George

    2010-03-01

    In an analysis of amyloid pathology in Alzheimer disease, we used an in situ approach to identify amyloid-beta (Abeta) accumulation and oxidative damage to nucleic acids in postmortem brain tissue of the hippocampal formation from subjects with Alzheimer disease. When carboxyl-terminal-specific antibodies directed against Abeta40 and Abeta42 were used for immunocytochemical analyses, Abeta42 was especially apparent within the neuronal cytoplasm, at sites not detected by the antibody specific to Abeta-oligomer. In comparison to the Abeta42-positive neurons, neurons bearing oxidative damage to nucleic acids were more widely distributed in the hippocampus. Comparative density measurements of the immunoreactivity revealed that levels of intraneuronal Abeta42 were inversely correlated with levels of intraneuronal 8-hydroxyguanosine, an oxidized nucleoside (r=- 0.61, p<0.02). Together with recent evidence that the Abeta peptide can act as an antioxidant, these results suggest that intraneuronal accumulation of non-oligomeric Abeta may be a compensatory response in neurons to oxidative stress in Alzheimer disease.

  13. Transcriptomic analysis for elucidating the physiological effects of 5-aminolevulinic acid accumulation on Corynebacterium glutamicum.

    PubMed

    Yu, Xiaoli; Jin, Haiying; Cheng, Xuelian; Wang, Qian; Qi, Qingsheng

    2016-11-01

    5-Aminolevulinic acid (ALA), the committed intermediate of the heme biosynthetic pathway, attracts close attention among researchers because of its potential applications to cancer treatment and agriculture. Overexpression of heterologous hemA and hemL, which encode glutamyl-tRNA reductase and glutamate-1-semialdehyde aminotransferase, respectively, in Corynebacterium glutamicum produces ALA, although whether ALA accumulation causes unintended effects on the host is unknown. Here we used an integrated systems approach to compare global transcriptional changes induced by the expression of hemA and hemL. Metabolic pathway such as glycolysis was inhibited, but tricarboxylic acid cycle, pentose phosphate pathway, and respiratory metabolism were stimulated. Moreover, the transcriptional levels of certain genes involved in heme biosynthesis were up-regulated, and the data implicate the two-component system (TCS) HrrSA was involved in the regulation of heme synthesis. With these understandings, it is proposed that ALA accumulation stimulates heme synthesis pathway and respiratory metabolism. Our study illuminates the physiological effects of overexpressing hemA and hemL on the phenotype of C. glutamicum and contributes important insights into the regulatory mechanisms of the heme biosynthetic pathways.

  14. Comparative proteomics of Rhizopus delemar ATCC 20344 unravels the role of amino acid catabolism in fumarate accumulation

    PubMed Central

    Sloothaak, Jasper; van Heck, Ruben G.A.; Martins dos Santos, Vitor A.P.; Suarez-Diez, Maria

    2017-01-01

    The filamentous fungus Rhizopus delemar naturally accumulates relatively high amounts of fumarate. Although the culture conditions that increase fumarate yields are well established, the network underlying the accumulation of fumarate is not yet fully understood. We set out to increase the knowledge about fumarate accumulation in R. delemar. To this end, we combined a transcriptomics and proteomics approach to identify key metabolic pathways involved in fumarate production in R. delemar, and propose that a substantial part of the fumarate accumulated in R. delemar during nitrogen starvation results from the urea cycle due to amino acid catabolism. PMID:28382234

  15. Reducing isozyme competition increases target fatty acid accumulation in seed triacylglycerols of transgenic Arabidopsis.

    PubMed

    van Erp, Harrie; Shockey, Jay; Zhang, Meng; Adhikari, Neil D; Browse, John

    2015-05-01

    One goal of green chemistry is the production of industrially useful fatty acids (FAs) in crop plants. We focus on hydroxy fatty acids (HFAs) and conjugated polyenoic FAs (α-eleostearic acids [ESAs]) using Arabidopsis (Arabidopsis thaliana) as a model. These FAs are found naturally in seed oils of castor (Ricinus communis) and tung tree (Vernicia fordii), respectively, and used for the production of lubricants, nylon, and paints. Transgenic oils typically contain less target FA than that produced in the source species. We hypothesized that competition between endogenous and transgenic isozymes for substrates limits accumulation of unique FAs in Arabidopsis seeds. This hypothesis was tested by introducing a mutation in Arabidopsis diacylglycerol acyltransferase1 (AtDGAT1) in a line expressing castor FA hydroxylase and acyl-Coenzyme A:RcDGAT2 in its seeds. This led to a 17% increase in the proportion of HFA in seed oil. Expression of castor phospholipid:diacylglycerol acyltransferase 1A in this line increased the proportion of HFA by an additional 12%. To determine if our observations are more widely applicable, we investigated if isozyme competition influenced production of ESA. Expression of tung tree FA conjugase/desaturase in Arabidopsis produced approximately 7.5% ESA in seed lipids. Coexpression of VfDGAT2 increased ESA levels to approximately 11%. Overexpression of VfDGAT2 combined with suppression of AtDGAT1 increased ESA accumulation to 14% to 15%. Our results indicate that isozyme competition is a limiting factor in the engineering of unusual FAs in heterologous plant systems and that reduction of competition through mutation and RNA suppression may be a useful component of seed metabolic engineering strategies.

  16. Proteolysis of chloroplast proteins is responsible for accumulation of free amino acids in dark-treated tea (Camellia sinensis) leaves.

    PubMed

    Chen, Yiyong; Fu, Xiumin; Mei, Xin; Zhou, Ying; Cheng, Sihua; Zeng, Lanting; Dong, Fang; Yang, Ziyin

    2017-03-22

    Shade management (dark treatment) on tea (Camellia sinensis) plants is a common approach to improve free amino acids in raw materials of tea leaves. However, the reason for amino acid accumulation in dark-treated tea leaves is still unknown. In the present study, dark treatment significantly increased content of free amino acids and reduced content of soluble proteins in tea leaves. Quantitative proteomics analysis showed that most enzymes involved in biosyntheses of amino acids were down-accumulated by dark treatment. Chloroplast numbers reduced in dark-treated leaves and the content of soluble proteins reduced in the chloroplasts isolated from dark-treated leaves compared to control. These suggest that proteolysis of chloroplast proteins contributed to amino acid accumulation in dark-treated leaves. Two chloroplasts proteases, ATP-dependent Clp protease proteolytic subunit 3 and protease Do-like 2, were up-accumulated in dark-treated leaves. This study firstly elucidated the mechanism of accumulation of amino acids in dark-treated tea leaves.

  17. Optimization of a histopathological biomarker for sphingomyelin accumulation in acid sphingomyelinase deficiency.

    PubMed

    Taksir, Tatyana V; Johnson, Jennifer; Maloney, Colleen L; Yandl, Emily; Griffiths, Denise; Thurberg, Beth L; Ryan, Susan

    2012-08-01

    Niemann-Pick disease (types A and B), or acid sphingomyelinase deficiency, is an inherited deficiency of acid sphingomyelinase, resulting in intralysosomal accumulation of sphingomyelin in cells throughout the body, particularly within those of the reticuloendothelial system. These cellular changes result in hepatosplenomegaly and pulmonary infiltrates in humans. A knockout mouse model mimics many elements of human ASMD and is useful for studying disease histopathology. However, traditional formalin-fixation and paraffin embedding of ASMD tissues dissolves sphingomyelin, resulting in tissues with a foamy cell appearance, making quantitative analysis of the substrate difficult. To optimize substrate fixation and staining, a modified osmium tetroxide and potassium dichromate postfixation method was developed to preserve sphingomyelin in epon-araldite embedded tissue and pulmonary cytology specimens. After processing, semi-thin sections were incubated with tannic acid solution followed by staining with toluidine blue/borax. This modified method provides excellent preservation and staining contrast of sphingomyelin with other cell structures. The resulting high-resolution light microscopy sections permit digital quantification of sphingomyelin in light microscopic fields. A lysenin affinity stain for sphingomyelin was also developed for use on these semi-thin epon sections. Finally, ultrathin serial sections can be cut from these same tissue blocks and stained for ultrastructural examination by electron microscopy.

  18. Arsenic accumulation and speciation in rice grown in arsanilic acid-elevated paddy soil.

    PubMed

    Geng, Anjing; Wang, Xu; Wu, Lishu; Wang, Fuhua; Chen, Yan; Yang, Hui; Zhang, Zhan; Zhao, Xiaoli

    2017-03-01

    P-arsanilic acid (AsA) is a emerging but less concerned contaminant used in animal feeding operations, for it can be degraded to more toxic metabolites after being excreted by animals. Rice is the staple food in many parts of the world, and also more efficient in accumulating arsenic (As) compared to other cereals. However, the uptake and transformation of AsA by rice is unclear. This study aimed to evaluate the potential risk of using AsA as a feed additive and using the AsA contaminated animal manure as a fertilizer. Five rice cultivars were grown in soil containing 100mg AsA/kg soil, after harvest, As species and their concentrations in different tissues were determined. Total As concentration of the hybrid rice cultivar was more than conventional rice cultivars for whole rice plant. For rice organs, the highest As concentration was found in roots. AsA could be absorbed by rice, partly degraded and converted to arsenite, monomethylarsonic acid, dimethylarsinic acid, arsenate. The number of As species and their concentrations in each cultivar were related to their genotypes. The soil containing 100mg AsA/kg or more is unsuitable for growing rice. The use of AsA and the disposal of animal manure requires detailed attention.

  19. Expression of the inactive ZmMEK1 induces salicylic acid accumulation and salicylic acid-dependent leaf senescence.

    PubMed

    Li, Yuan; Chang, Ying; Zhao, Chongchong; Yang, Hailian; Ren, Dongtao

    2016-08-01

    Leaf senescence is the final leaf developmental process that is regulated by both intracellular factors and environmental conditions. The mitogen-activated protein kinase (MAPK) signaling cascades have been shown to play important roles in regulating leaf senescence; however, the component(s) downstream of the MAPK cascades in regulating leaf senescence are not fully understood. Here we showed that the transcriptions of ZmMEK1, ZmSIMK1, and ZmMPK3 were induced during dark-induced maize leaf senescence. Furthermore, in-gel kinase analysis revealed the 42 kDa MAPK was activated. ZmMEK1 interacted with ZmSIMK1 in yeast and maize mesophyll protoplasts and ZmSIMK1 was activated by ZmMEK1 in vitro. Expression of a dominant negative mutant of ZmMEK1 in Arabidopsis transgenic plants induced salicylic acid (SA) accumulation and SA-dependent leaf senescence. ZmMEK1 interacted with Arabidopsis MPK4 in yeast and activated MPK4 in vitro. SA treatment accelerated dark-induced maize leaf senescence. Moreover, blockage of MAPK signaling increased endogenous SA accumulation in maize leaves. These findings suggest that ZmMEK1-ZmSIMK1 cascade and its modulating SA levels play important roles in regulating leaf senescence.

  20. Accumulation of the Antibiotic Phenazine-1-Carboxylic Acid in the Rhizosphere of Dryland Cereals

    PubMed Central

    Mavrodi, Dmitri V.; Mavrodi, Olga V.; Parejko, James A.; Bonsall, Robert F.; Kwak, Youn-Sig; Paulitz, Timothy C.; Weller, David M.

    2012-01-01

    Natural antibiotics are thought to function in the defense, fitness, competitiveness, biocontrol activity, communication, and gene regulation of microorganisms. However, the scale and quantitative aspects of antibiotic production in natural settings are poorly understood. We addressed these fundamental questions by assessing the geographic distribution of indigenous phenazine-producing (Phz+) Pseudomonas spp. and the accumulation of the broad-spectrum antibiotic phenazine-1-carboxylic acid (PCA) in the rhizosphere of wheat grown in the low-precipitation zone (<350 mm) of the Columbia Plateau and in adjacent, higher-precipitation areas. Plants were collected from 61 commercial wheat fields located within an area of about 22,000 km2. Phz+ Pseudomonas spp. were detected in all sampled fields, with mean population sizes ranging from log 3.2 to log 7.1 g−1 (fresh weight) of roots. Linear regression analysis demonstrated a significant inverse relationship between annual precipitation and the proportion of plants colonized by Phz+ Pseudomonas spp. (r2 = 0.36, P = 0.0001). PCA was detected at up to nanomolar concentrations in the rhizosphere of plants from 26 of 29 fields that were selected for antibiotic quantitation. There was a direct relationship between the amount of PCA extracted from the rhizosphere and the population density of Phz+ pseudomonads (r2 = 0.46, P = 0.0006). This is the first demonstration of accumulation of significant quantities of a natural antibiotic across a terrestrial ecosystem. Our results strongly suggest that natural antibiotics can transiently accumulate in the plant rhizosphere in amounts sufficient not only for inter- and intraspecies signaling but also for the direct inhibition of sensitive organisms. PMID:22138981

  1. Lipoteichoic acid promotes nuclear accumulation of β-catenin via AKT in human gingival fibroblasts.

    PubMed

    Gutiérrez-Venegas, Gloria; Cardoso-Jiménez, Patricia

    2011-09-01

    Treatment of human gingival fibroblasts (HGFs) with lipoteichoic acid (LTA) results in the activation of multiple signaling pathways. Exposure of HGF to LTA has been shown to result in the activation of phosphatidylinositol 3-kinase (PI3K). The aim of this study was to evaluate the effects of LTA-induced PI3K activation in HGFs. We found that LTA treatment results in the phosphorylation of AKT and glycogen synthase kinase (GSK-3). Inactivation of GSK-3 promotes the nuclear accumulation of β-catenin and expression of connexin43. Treatment with PI3K inhibitors, wortmannin and LY294002, inhibited LTA-induced phosphorylation of AKT and GSK-3, demonstrating that these events require PI3K activation. This report is the first demonstration that LTA treatment activates AKT in HGFs.

  2. Use of a Gluconobacter frateurii mutant to prevent dihydroxyacetone accumulation during glyceric acid production from glycerol.

    PubMed

    Habe, Hiroshi; Shimada, Yuko; Fukuoka, Tokuma; Kitamoto, Dai; Itagaki, Masayuki; Watanabe, Kunihiro; Yanagishita, Hiroshi; Yakushi, Toshiharu; Matsushita, Kazunobu; Sakaki, Keiji

    2010-01-01

    To prevent dihydroxyacetone (DHA) by-production during glyceric acid (GA) production from glycerol using Gluconobacter frateurii, we used a G. frateurii THD32 mutant, ΔsldA, in which the glycerol dehydrogenase subunit-encoding gene (sldA) was disrupted, but ΔsldA grew much more slowly than the wild type, growth starting after a lag of 3 d under the same culture conditions. The addition of 1% w/v D-sorbitol to the medium improved both the growth and the GA productivity of the mutant, and ΔsldA produced 89.1 g/l GA during 4 d of incubation without DHA accumulation.

  3. Ellagic acid suppresses lipid accumulation by suppressing early adipogenic events and cell cycle arrest.

    PubMed

    Woo, Mi-Seon; Choi, Hyeon-Son; Seo, Min-Jung; Jeon, Hui-Jeon; Lee, Boo-Yong

    2015-03-01

    Ellagic acid (EA) is a natural polyphenol found in various fruits and vegetables. In this study, we examined the inhibitory effect of EA on fat accumulation in 3T3-L1 cells during adipogenesis. Our data showed that EA reduced fat accumulation by down-regulating adipogenic markers such as peroxisome proliferator activated receptor γ (PPARγ) and the CCAAT/enhancer binding protein α (C/EBPα) at the mRNA and protein levels in a dose-dependent manner. We found that the decrease in adipogenic markers resulted from reduced expression of some early adipogenic transcription factors such as KLF4, KLF5, Krox20, and C/EBPβ within 24 h. Also, these inhibitions were correlated with down-regulation of TG synthetic enzymes, causing inhibition of triglyceride (TG) levels in 3T3-L1 cells investigated by ORO staining and in zebrafish investigated by TG assay. Additionally, the cell cycle analysis showed that EA inhibited cell cycle progression by arresting cells at the G0/G1 phase.

  4. Supplemental phytic acid and microbial phytase change zinc bioavailability and cadmium accumulation in growing rats.

    PubMed

    Rimbach, G; Brandt, K; Most, E; Pallauf, J

    1995-07-01

    Three groups of individually housed albino rats (n = 6 each, initial average weight = 47 g) were fed diets based on egg white and corn starch over a 4-week period. All diets were supplemented with 15 mg/kg of Zn and 5 mg/kg of Cd. Group I (Control) was fed the basal diet free of phytic acid (PA) and phytase. By replacing corn starch by 0.5% PA (as NaPA) in groups II and III, a molar PA/Zn ratio of 33 was obtained. In group III, 2000 U of microbial phytase per kg diet were added. Addition of PA to diet (group II) resulted in a significant decrease in growth and zinc status. The negative effect of dietary PA on growth and zinc status was considerably counteracted by the supplementation of 2000 U microbial phytase (group III). In group I the highest apparent zinc absorption (58.2%) was measured. The addition of 0.5% PA (group II) significantly decreased apparent zinc absorption to 23.4%. In rats receiving the phytase-enriched diet (group III) 46.5% of ingested zinc was apparently absorbed. Liver cadmium concentration in rats fed the diet containing PA was significantly higher than that in the control group, whereas phytase supplementation lowered liver cadmium accumulation. In tendency similar effects were obtained for kidney cadmium accumulation.

  5. Endogenous salicylic acid accumulation is required for chilling tolerance in cucumber (Cucumis sativus L.) seedlings.

    PubMed

    Dong, Chun-Juan; Li, Liang; Shang, Qing-Mao; Liu, Xin-Yan; Zhang, Zhi-Gang

    2014-10-01

    Salicylic acid (SA) is an important plant hormone, and its exogenous application can induce tolerance to multiple environmental stresses in plants. In this study, we examine the potential involvement of endogenous SA in response to chilling in cucumber (Cucumis sativus L.) seedlings. A low temperature of 8 °C induces a moderate increase in endogenous SA levels. Chilling stimulates the enzymatic activities and the expression of genes for phenylalanine ammonia-lyase (PAL) and benzoic acid-2-hydroxylase rather than isochorismate synthase. This indicates that the PAL enzymatic pathway contributes to chilling-induced SA production. Cucumber seedlings pretreated with SA biosynthesis inhibitors accumulate less endogenous SA and suffer more from chilling damage. The expression of cold-responsive genes is also repressed by SA inhibitors. The reduction in stress tolerance and in gene expression can be restored by the exogenous application of SA, confirming the critical roles of SA in chilling responses in cucumber seedlings. Furthermore, the inhibition of SA biosynthesis under chilling stress results in a prolonged and enhanced hydrogen peroxide (H2O2) accumulation. The application of exogenous SA and the chemical scavenger of H2O2 reduces the excess H2O2 and alleviates chilling injury. In contrast, the protective effects of SA are negated by foliar spraying with high concentrations of H2O2 and an inhibitor of the antioxidant enzyme. These results suggest that endogenous SA is required in response to chilling stress in cucumber seedlings, by modulating the expression of cold-responsive genes and the precise induction of cellular H2O2 levels.

  6. Accumulation of different sulfur fractions in Chinese forest soil under acid deposition.

    PubMed

    Wang, Zhanyi; Zhang, Xiaoshan; Zhang, Yi; Wang, Zhangwei; Mulder, Jan

    2011-09-01

    Atmogenic sulfur (S) deposition loading by acid rain is one of the biggest environmental problems in China. It is important to know the accumulated S stored in soil, because eventually the size (and also the "desorption" rate) determines how rapidly the soil water pH responds to decrease in S deposition. The S fractions and the ratio of total carbon/total sulfur (C/S) of forest soil in 9 catchments were investigated by comparing soils at the rural and urban sites in China. The S fractions included water-soluble sulfate-S (SO(4)-S), adsorbed SO(4)-S, insoluble SO(4)-S and organic S. The ratio of C/S in soil at the rural site was significantly (p < 0.05) greater than that at the urban site. C/S of soil in the A horizon was significantly (p < 0.05) and negatively correlated with the wet S-deposition rate. The ratio of C/S presents a better indicator for atmogenic S loading. Organic S was the dominant form in soils at rural sites; contributing more than 69% of the total S in the uppermost 30 cm soil. Organic S and adsorbed SO(4)-S were the main forms of S in soil at urban sites. High contents of water-soluble SO(4)-S and adsorbed SO(4)-S were found in uppermost 30 cm soils at urban sites but not at rural sites. Decades of acid rain have caused accumulation of inorganic SO(4)-S in Chinese forest soil especially at the urban sites. The soil at urban sites had been firstly acidified, and the impacts on the forest ecosystem in these areas should be noticed.

  7. The toc132toc120 heterozygote mutant of Arabidopsis thaliana accumulates reduced levels of hexadecatrienoic acid.

    PubMed

    Afitlhile, Meshack; Duffield-Duncan, Kayla; Fry, Morgan; Workman, Samantha; Hum-Musser, Sue; Hildebrand, David

    2015-11-01

    A null and heterozygous mutant for the Arabidopsis thaliana TOC132 and TOC120 genes accumulates increased levels of 16:0 and decreased 16:3, suggesting altered homeostasis in fatty acid synthesis. The FAD5 gene encodes a plastid desaturase that catalyzes the first step in the synthesis of 16:3 in monogalactosyldiacylglycerol (MGDG). In non-acclimated toc132toc120+/- mutant plants, the FAD5 gene was repressed and this correlated with decreased levels of 16:3. In cold-acclimated mutant however, the FAD5 gene was upregulated and there was a small increase in 16:3 levels relative to the non-acclimated mutant plants. The MGD1 gene was expressed at control levels and the mutant accumulated levels of MGDG that were similar to the wild type. In the mutant however, MGDG had decreased 16:3 levels, suggesting that the activity of FAD5 desaturase was compromised. In the mutant, the FAD2 and FAD3 genes were downregulated but levels of 18:3-PC were increased, suggesting posttranscriptional regulation for the ER-localized fatty acid desaturases. The Toc120 or Toc159 receptor is likely to compensate for a defective Toc132 receptor. In the cold-acclimated mutant, the TOC159 gene was repressed ca. 300-fold, whereas the TOC120 gene was repressed 7-fold relative to the non-acclimated wild type. Thus, the TOC159 gene is more sensitive to cold-stress and might not compensate for defect in the TOC132 gene under these conditions. Overall, these data show that a mutation in the TOC132 gene results in decreased 16:3 levels, indicating the need for an intact Toc132/Toc120 receptor, presumably to facilitate the import of the FAD5 preprotein into chloroplasts.

  8. Triglyceride accumulation and fatty acid profile changes in Chlorella (Chlorophyta) during high pH-induced cell cycle inhibition

    SciTech Connect

    Guckert, J.B.; Cooksey, K.E. )

    1990-03-01

    Alkaline pH stress resulted in triglyceride (TG) accumulation in Chlorella CHLOR1 and was independent of medium nitrogen or carbon levels. Based on morphological observations, alkaline pH inhibited autospore release, thus increasing the time for cell cycle completion. Autospore release has been postulated to coincide with TG utilization within the microalgal cell division cycle. The alkaline pH stress affected lipid accumulation by inhibiting the cell division cycle prior to autospore release and, therefore, prior to TG utilization. Cells inhibited in this manner showed an increase in TG accumulation but a decrease in both membrane lipid classes (glycolipid and polar lipid). Unlike TG fatty acid profiles, membrane lipid fatty acid profiles were not stable during TG accumulation. The membrane profiles became similar to the TG, i.e. less unsaturated than in the membrane lipids of unstressed control cells.

  9. Defense Priming and Jasmonates: A Role for Free Fatty Acids in Insect Elicitor-Induced Long Distance Signaling

    PubMed Central

    Li, Ting; Cofer, Tristan; Engelberth, Marie; Engelberth, Jurgen

    2016-01-01

    Green leaf volatiles (GLV) prime plants against insect herbivore attack resulting in stronger and faster signaling by jasmonic acid (JA). In maize this response is specifically linked to insect elicitor (IE)-induced signaling processes, which cause JA accumulation not only around the damage site, but also in distant tissues, presumably through the activation of electrical signals. Here, we present additional data further characterizing these distal signaling events in maize. Also, we describe how exposure to GLV increases free fatty acid (fFA) levels in maize seedlings, but also in other plants, and how increased fFA levels affect IE-induced JA accumulation. Increased fFA, in particular α-linolenic acid (LnA), caused a significant increase in JA accumulation after IE treatment, while JA induced by mechanical wounding (MW) alone was not affected. We also identified treatments that significantly decreased certain fFA level including simulated wind and rain. In such treated plants, IE-induced JA accumulation was significantly reduced when compared to un-moved control plants, while MW-induced JA accumulation was not significantly affected. Since only IE-induced JA accumulation was altered by changes in the fFA composition, we conclude that changing levels of fFA affect primarily IE-induced signaling processes rather than serving as a substrate for JA. PMID:27135225

  10. Methamphetamine absorption by skin lipids: accumulated mass, partition coefficients, and the influence of fatty acids.

    PubMed

    Parker, K; Morrison, G

    2016-08-01

    Occupants of former methamphetamine laboratories, often residences, may experience increased exposure through the accumulation of the methamphetamine in the organic films that coat skin and indoor surfaces. The objectives of this study were to determine equilibrium partition coefficients of vapor-phase methamphetamine with artificial sebum (AS-1), artificial sebum without fatty acids (AS-2), and real skin surface films, herein called skin oils. Sebum and skin oil-coated filters were exposed to vapor-phase methamphetamine at concentrations ranging from 8 to 159 ppb, and samples were analyzed for exposure time periods from 2 h to 60 days. For a low vapor-phase methamphetamine concentration range of ~8-22 ppb, the equilibrium partition coefficient for AS-1 was 1500 ± 195 μg/g/ppb. For a high concentration range of 98-112 ppb, the partition coefficient was lower, 459 ± 80 μg/g/ppb, suggesting saturation of the available absorption capacity. The low partition coefficient for AS-2 (33 ± 6 μg/g/ppb) suggests that the fatty acids in AS-1 and skin oil are responsible for much high partition coefficients. We predict that the methamphetamine concentration in skin lipids coating indoor surfaces can exceed recommended surface remediation standards even for air concentrations well below 1 ppb.

  11. Oxalic acid enhances Cr tolerance in the accumulating plant Leersia hexandra Swartz.

    PubMed

    Wang, Dunqiu; Zhang, Xuehong; Liu, Jie; Zhu, Yinian; Zhang, Hui; Zhang, Aili; Jin, Xiaodan

    2012-12-01

    This study examined the relationship between oxalic acid and Cr tolerance in an accumulating plant Leersia hexandra Swartz. The plants grown in hydroponics were exposed to Cr at 0, 5, 30, and 60 mg/L (without oxalate), and 0, 40, and 80 mg/L concentrations of Cr (with 70 mg/L oxalate or without oxalate). The results showed that more than 50% of Cr in shoots was found in HCl-extracted fraction (chromium oxalate) when the plants were exposed to Cr. Cr supply significantly increased oxalate concentration in shoots of L. hexandra (p < 0.05), but did not increase oxalate concentration in roots. Under 80 mg/L Cr stress, electrolyte leakages from roots and shoots with oxalate treatment were both significantly lower than those without oxalate treatment (p < 0.05), indicating exogenous oxalate supply alleviated Cr-induced membrane damage. Oxalate added to growth solution ameliorated reduction of biomass and inhibition of root growth induced by Cr, which demonstrated that application of oxalate helped L. hexandra tolerate Cr stress. However, oxalate supply did not affect the Cr concentrations both in roots and shoots of L. hexandra. These results suggest that oxalic acid may act as an important chelator and takes part in detoxifying chromium in internal process of L. hexandra.

  12. The relation between Acid Volatile Sulfides (AVS) and metal accumulation in aquatic invertebrates: implications of feeding behavior and ecology.

    PubMed

    De Jonge, Maarten; Blust, Ronny; Bervoets, Lieven

    2010-05-01

    The present study evaluates the relationship between Acid Volatile Sulfides (AVS) and metal accumulation in invertebrates with different feeding behavior and ecological preferences. Natural sediments, pore water and surface water, together with benthic and epibenthic invertebrates were sampled at 28 Flemish lowland rivers. Different metals as well as metal binding sediment characteristics including AVS were measured and multiple regression was used to study their relationship with accumulated metals in the invertebrates taxa. Bioaccumulation in the benthic taxa was primarily influenced by total metal concentrations in the sediment. Regarding the epibenthic taxa metal accumulation was mostly explained by the more bioavailable metal fractions in both the sediment and the water. AVS concentrations were generally better correlated with metal accumulation in the epibenthic invertebrates, rather than with the benthic taxa. Our results indicated that the relation between AVS and metal accumulation in aquatic invertebrates is highly dependent on feeding behavior and ecology.

  13. A reconfigured Kennedy pathway which promotes efficient accumulation of medium chain fatty acids in leaf oils.

    PubMed

    Reynolds, Kyle B; Taylor, Matthew C; Cullerne, Darren P; Blanchard, Christopher L; Wood, Craig C; Singh, Surinder P; Petrie, James R

    2017-03-16

    Medium chain fatty acids (MCFA, C6-14 fatty acids) are an ideal feedstock for biodiesel and broader oleochemicals. In recent decades, several studies have used transgenic engineering to produce MCFA in seeds oils, though these modifications result in unbalance membrane lipid profiles that impair oil yields and agronomic performance. Given the ability to engineer non-seed organs to produce oils, we have previously demonstrated that MCFA profiles can be produced in leaves, but this also results in unbalanced membrane lipid profiles and undesirable chlorosis and cell death. Here we demonstrate that the introduction of a diacylglycerol acyltransferase from oil palm, EgDGAT1, was necessary to channel nascent MCFA directly into leaf oils and therefore bypassing MCFA residing in membrane lipids. This pathway resulted in increased flux towards MCFA rich leaf oils, reduced MCFA in leaf membrane lipids and, crucially, the alleviation of chlorosis. Deep sequencing of African oil palm (Elaeis guineensis) and coconut palm (Cocos nucifera) generated candidate genes of interest, which were then tested for their ability to improve oil accumulation. Thioesterases were explored for the production of lauric acid (C12:0) and myristic (C14:0). The thioesterases from Umbellularia californica and Cinnamomum camphora produced a total of 52% C12:0 and 40% C14:0, respectively, in transient leaf assays. This study demonstrated that the introduction of a complete acyl-CoA dependent pathway for the synthesis of MFCA-rich oils avoided disturbing membrane homeostasis and cell death phenotypes. This study outlines a transgenic strategy for the engineering of biomass crops with high levels of MCFA rich leaf oils. This article is protected by copyright. All rights reserved.

  14. EDTA and hydrochloric acid effects on mercury accumulation by Lupinus albus.

    PubMed

    Rodríguez, Luis; Alonso-Azcárate, Jacinto; Villaseñor, José; Rodríguez-Castellanos, Laura

    2016-12-01

    The efficiency of white lupine (Lupinus albus) to uptake and accumulate mercury from a soil polluted by mining activities was assessed in a pot experiment with chemically assisted phytoextraction. The mobilizing agents tested were ethylenediaminetetracetic acid (EDTA) and hydrochloric acid (HCl). Two doses of each amendment were used (0.5 and 1.0 g of amendment per kg of soil), and unamended pots were used as a control. Addition of HCl to the soil did not negatively affect plant biomass, while the use of EDTA led to a significant decrease in plant growth when compared to that found for non-treated pots, with plants visually showing symptoms of toxicity. The addition of hydrochloric acid increased root, shoot and total plant Hg uptake of white lupine by 3.7 times, 3.1 times and 3.5 times, respectively, in relation to non-amended plants. The greatest efficiency was obtained for the highest HCl dose. EDTA led to higher concentrations of total plant Hg than that found with the control, but, due to the aforementioned decrease in plant biomass, the Hg phytoextraction yield was not significantly increased. These results were attributed to the capability of both amendments to form stable Hg complexes. The concentration of Hg in the water of the soil pores after the phytoextraction experiment was very low for all treatments, showing that risks derived from metal leaching could be partially avoided by using doses and chemicals suitable to the concentration of metal in the soil and plant performance.

  15. Anaerobic biodegradation of oleic and palmitic acids: evidence of mass transfer limitations caused by long chain fatty acid accumulation onto the anaerobic sludge.

    PubMed

    Pereira, M A; Pires, O C; Mota, M; Alves, M M

    2005-10-05

    Palmitic acid was the main long chain fatty acids (LCFA) that accumulated onto the anaerobic sludge when oleic acid was fed to an EGSB reactor. The conversion between oleic and palmitic acid was linked to the biological activity. When palmitic acid was fed to an EGSB reactor it represented also the main LCFA that accumulated onto the sludge. The way of palmitic acid accumulation was different in the oleic and in the palmitic acid fed reactors. When oleic acid was fed, the biomass-associated LCFA (83% as palmitic acid) were mainly adsorbed and entrapped in the sludge that became "encapsulated" by an LCFA layer. However, when palmitic acid was fed, the biomass-associated LCFA (the totality as palmitic acid) was mainly precipitated in white spots like precipitates in between the sludge, which remained "non-encapsulated." The two sludges were compared in terms of the specific methanogenic activity (SMA) in the presence of acetate, propionate, butyrate, and H(2)CO(2), before and after the mineralization of similar amounts of biomass-associated LCFA (4.6 and 5.2 g COD-LCFA/g of volatile suspended solids (VSS), for the oleic and palmitic acid fed sludge, respectively). The "non-encapsulated," sludge exhibited a considerable initial methanogenic activity on all the tested substrates, with the single exception of butyrate. However, with the "encapsulated" sludge only methane production from ethanol and H(2)/CO(2) was detected, after a lag phase of about 50 h. After mineralization of the biomass-associated LCFA, both sludges exhibited activities of similar order of magnitude in the presence of the same individual substrates and significantly higher than before. The results evidenced that LCFA accumulation onto the sludge can create a physical barrier and hinder the transfer of substrates and products, inducing a delay on the initial methane production. Whatever the mechanism, metabolic or physical, that is behind this inhibition, it is reversible, being eliminated after the

  16. Accumulation of the mycotoxin patulin in the presence of gluconic acid contributes to pathogenicity of Penicillium expansum.

    PubMed

    Barad, Shiri; Horowitz, Sigal Brown; Kobiler, Ilana; Sherman, Amir; Prusky, Dov

    2014-01-01

    Penicillium expansum, the causal agent of blue mold rot, causes severe postharvest fruit maceration through secretion of D-gluconic acid (GLA) and secondary metabolites such as the mycotoxin patulin in colonized tissue. GLA involvement in pathogenicity has been suggested but the mechanism of patulin accumulation and its contribution to P. expansum pathogenicity remain unclear. The roles of GLA and patulin accumulation in P. expansum pathogenicity were studied using i) glucose oxidase GOX2-RNAi mutants exhibiting decreased GOX2 expression, GLA accumulation, and reduced pathogenicity; ii) IDH-RNAi mutants exhibiting downregulation of IDH (the last gene in patulin biosynthesis), reduced patulin accumulation, and no effect on GLA level; and iii) PACC-RNAi mutants exhibiting downregulation of both GOX2 and IDH that reduced GLA and patulin production. Present results indicate that conditions enhancing the decrease in GLA accumulation by GOX2-RNAi and PACC-RNAi mutants, and not low pH, affected patulin accumulation, suggesting GLA production as the driving force for further patulin accumulation. Thus, it is suggested that GLA accumulation may modulate patulin synthesis as a direct precursor under dynamic pH conditions modulating the activation of the transcription factor PACC and the consequent pathogenicity factors, which contribute to host-tissue colonization by P. expansum.

  17. Ammonia activates pacC and patulin accumulation in an acidic environment during apple colonization by Penicillium expansum.

    PubMed

    Barad, Shiri; Espeso, Eduardo A; Sherman, Amir; Prusky, Dov

    2016-06-01

    Penicillium expansum, the causal agent of blue mould rot, causes severe post-harvest fruit maceration simultaneously with the secretion of d-gluconic acid (GLA) and the mycotoxin patulin in colonized tissue. The factor(s) inducing patulin biosynthesis during colonization of the host acidic environment is unclear. During the colonization of apple fruit in vivo and growth in culture, P. expansum secretes pH-modulating GLA and ammonia. Although patulin and its possible opportunistic precursor GLA accumulate together during fungal development, ammonia is detected on the colonized tissue's leading edge and after extended culture, close to patulin accumulation. Here, we demonstrate ammonia-induced transcript activation of the global pH modulator PacC and patulin accumulation in the presence of GLA by: (i) direct exogenous treatment of P. expansum growing on solid medium; (ii) direct exogenous treatment on colonized apple tissue; (iii) growth under self-ammonia production conditions with limited carbon; and (iv) analysis of the transcriptional response to ammonia of the patulin biosynthesis cluster. Ammonia induced patulin accumulation concurrently with the transcript activation of pacC and patulin biosynthesis cluster genes, indicating the regulatory effect of ammonia on pacC transcript expression under acidic conditions. Electrophoretic mobility shift assays using P. expansum PacC and antibodies to the different cleaved proteins showed that PacC is not protected against proteolytic signalling at pH 4.5 relative to pH 7.0, but NH4 addition did not further enhance its proteolytic cleavage. Ammonia enhanced the activation of palF transcript in the Pal pathway under acidic conditions. Ammonia accumulation in the host environment by the pathogen under acidic pH may be a regulatory cue for pacC activation, towards the accumulation of secondary metabolites, such as patulin.

  18. Short communication: malic acid does not promote vaccenic acid accumulation in mixed ruminal fluid with fractionated fish oil by a rumen-simulation technique.

    PubMed

    Liu, L; Wang, J Q; Bu, D P; Liu, S J; Liang, S; Wei, H Y; Zhou, L Y; Liu, K L

    2008-10-01

    The objective of this study was to determine whether malic acid could promote the accumulation of vaccenic acid in the rumen. The control diet was composed of a 65:35 ratio of forage to concentrate with 1% (dry matter basis) added fractionated fish oil (rich in docosahexaenoic acid), and treatment diets consisted of the control diet with added malic acid to achieve final concentrations of 10 mM (treatment 1) and 20 mM (treatment 2), respectively. The experiment was conducted with rumen-simulation equipment (Rusitec) consisting of 9 fermenters. Each treatment included 3 fermenters as replicates. After 7 d of incubation, concentrations of vaccenic acid from treatment 1 (4.38% fatty acids) and treatment 2 (4.46% fatty acids) were similar to that of the control treatment (4.51% fatty acids). The disappearance of docosahexaenoic acid was not different among the control, treatment 1, or treatment 2. These data indicated that malic acid did not promote the accumulation of vaccenic acid in ruminal fluid.

  19. The Phosphatidylcholine Diacylglycerol Cholinephosphotransferase Is Required for Efficient Hydroxy Fatty Acid Accumulation in Transgenic Arabidopsis1[W][OA

    PubMed Central

    Hu, Zhaohui; Ren, Zhonghai; Lu, Chaofu

    2012-01-01

    We previously identified an enzyme, phosphatidylcholine diacylglycerol cholinephosphotransferase (PDCT), that plays an important role in directing fatty acyl fluxes during triacylglycerol (TAG) biosynthesis. The PDCT mediates a symmetrical interconversion between phosphatidylcholine (PC) and diacylglycerol (DAG), thus enriching PC-modified fatty acids in the DAG pool prior to forming TAG. We show here that PDCT is required for the efficient metabolism of engineered hydroxy fatty acids in Arabidopsis (Arabidopsis thaliana) seeds. When a fatty acid hydroxylase (FAH12) from castor (Ricinus communis) was expressed in Arabidopsis seeds, the PDCT-deficient mutant accumulated only about half the amount of hydroxy fatty acids compared with that in the wild-type seeds. We also isolated a PDCT from castor encoded by the RcROD1 (Reduced Oleate Desaturation1) gene. Seed-specific coexpression of this enzyme significantly increased hydroxy fatty acid accumulation in wild type-FAH12 and in a previously produced transgenic Arabidopsis line coexpressing a castor diacylglycerol acyltransferase 2. Analyzing the TAG molecular species and regiochemistry, along with analysis of fatty acid composition in TAG and PC during seed development, indicate that PDCT acts in planta to enhance the fluxes of fatty acids through PC and enrich the hydroxy fatty acids in DAG, and thus in TAG. In addition, PDCT partially restores the oil content that is decreased in FAH12-expressing seeds. Our results add a new gene in the genetic toolbox for efficiently engineering unusual fatty acids in transgenic oilseeds. PMID:22371508

  20. Overexpression of BAK1 causes salicylic acid accumulation and deregulation of cell death control genes.

    PubMed

    Kim, Sun Young; Shang, Yun; Joo, Se-Hwan; Kim, Seong-Ki; Nam, Kyoung Hee

    2017-03-18

    Since the BRI1-Associated Receptor Kinase 1 (BAK1) was firstly identified as a co-receptor of BRI1 that mediates brassinosteroids (BR) signaling, the functional roles of BAK1, as a versatile co-receptor for various ligand-binding leucine-rich repeat (LRR)-containing receptor-like kinase (RLKs), are being extended to involvement with plant immunity, cell death, stomatal development and ABA signaling in plants. During more than a decade of research on the BAK1, it has been known that transgenic Arabidopsis plants overexpressing BAK1 tagged with various reporters do not fully represent its natural functions. Therefore, in this study, we characterized the transgenic plants in which native BAK1 is overexpressed driven by its own promoter. We found that those transgenic plants were more sensitive to BR signaling but showed reduced growth patterns accompanied with spontaneous cell death features that are different from those seen in BR-related mutants. We demonstrated that more salicylic acid (SA) and hydrogen peroxide were accumulated and that expressions of the genes that are known to regulate cell death, such as BONs, BIRs, and SOBIR, were increased in the BAK1-overexpressing transgenic plants. These results suggest that pleiotropic phenotypic alterations shown in the BAK1- overexpressing transgenic plants result from the constitutive activation of SA-mediated defense responses.

  1. Stress-induced accumulation of wheat germ agglutinin and abscisic acid in roots of wheat seedlings

    SciTech Connect

    Cammue, B.P.A.; Broekaert, W.F.; Kellens, J.T.C.; Peumans, W.J. ); Raikhel, N.V. )

    1989-12-01

    Wheat germ agglutinin (WGA) levels in roots of 2-day-old wheat seedlings increased up to three-fold when stressed by air-drying. Similar results were obtained when seedling roots were incubated either in 0.5 molar mannitol or 180 grams per liter polyethylene glycol 6,000, with a peak level of WGA after 5 hours of stress. Longer periods of osmotic treatment resulted in a gradual decline of WGA in the roots. Since excised wheat roots incorporate more ({sup 35}S)cysteine into WGA under stress conditions, the observed increase of lectin levels is due to de novo synthesis. Measurement of abscisic acid (ABA) levels in roots of control and stressed seedlings indicated a 10-fold increase upon air-drying. Similarly, a five- and seven-fold increase of ABA content of seedling roots was found after 2 hours of osmotic stress by polyethylene glycol 6,000 and mannitol, respectively. Finally, the stress-induced increase of WGA in wheat roots could be inhibited by growing seedlings in the presence of fluridone, an inhibitor of ABA synthesis. These results indicate that roots of water-stressed wheat seedlings (a) contain more WGA as a result of an increased de novo synthesis of this lectin, and (b) exhibit higher ABA levels. The stress-induced increase of lectin accumulation seems to be under control of ABA.

  2. Liver free fatty acid (FFA) accumulation as an indicator of ischemic injury during cold preservation

    SciTech Connect

    Nemoto, E.M.; Kang, Y.; DeWolf, A.M.; Lin, M.R.; Bleyaert, A.L.; Winter, P.M.

    1987-05-01

    Reliable assessment of hepatic viability prior to harvest and transplant could improve graft success and aid in evaluating the efficacy of liver preservation techniques. Hepatic tissue metabolites, protein (Pr) synthesis, and ATP have been studied, but none reliably correlate with hepatic viability. Therefore, they studied changes in liver FFA relative to changes in ATP and Pr synthesis during cold ischemic preservation. Rats mechanically ventilated on 0.5% isoflurane/70% N/sub 2/O/30% O/sub 2/ were heparinized and their livers perfused with air-equilibrated Euro-Collins solution (ECS) at 0-4/sup 0/C and kept on ice. A piece of the liver was removed after 0, 2, 6, 8, 12, 24, 36 and 48 h of preservation for ATP and FFA analysis. A portion of the liver was sliced (250 ..mu..m thick) and incubated in vitro for /sup 14/C-lysine incorporation in albumin. ATP, FFA and Pr synthesis were unchanged in the first 8 h, but markedly decreased between 8 and 12 h with little change thereafter. In contrast, between 8 and 48 h, arachidonic and stearic acids increased by 5 and 2-fold, respectively. Changes in ATP and Pr synthesis correlate with the empirically derived clinical maximum of 8 to 12 h preservation. FFA accumulation appears to reflect hepatic ischemic injury and may be a means of evaluating the quality of a donor liver.

  3. Accumulation of arachidonic acid-containing phosphatidylinositol at the outer edge of colorectal cancer

    PubMed Central

    Hiraide, Takanori; Ikegami, Koji; Sakaguchi, Takanori; Morita, Yoshifumi; Hayasaka, Takahiro; Masaki, Noritaka; Waki, Michihiko; Sugiyama, Eiji; Shinriki, Satoru; Takeda, Makoto; Shibasaki, Yasushi; Miyazaki, Shinichiro; Kikuchi, Hirotoshi; Okuyama, Hiroaki; Inoue, Masahiro; Setou, Mitsutoshi; Konno, Hiroyuki

    2016-01-01

    Accumulating evidence indicates that cancer cells show specific alterations in phospholipid metabolism that contribute to tumour progression in several types of cancer, including colorectal cancer. Questions still remain as to what lipids characterize the outer edge of cancer tissues and whether those cancer outer edge-specific lipid compositions emerge autonomously in cancer cells. Cancer tissue-originated spheroids (CTOSs) that are composed of pure primary cancer cells have been developed. In this study, we aimed to seek out the cancer cell-autonomous acquisition of cancer outer edge-characterizing lipids in colorectal cancer by analysing phospholipids in CTOSs derived from colorectal cancer patients with matrix-assisted laser desorption/ionization (MALDI)-imaging mass spectrometry (IMS). A signal at m/z 885.5 in negative ion mode was detected specifically at the surface regions. The signal was identified as an arachidonic acid (AA)-containing phosphatidylinositol (PI), PI(18:0/20:4), by tandem mass spectrometry analysis. Quantitative analysis revealed that the amount of PI(18:0/20:4) in the surface region of CTOSs was two-fold higher than that in the medial region. Finally, PI(18:0/20:4) was enriched at the cancer cells/stromal interface in colorectal cancer patients. These data imply a possible importance of AA-containing PI for colorectal cancer progression, and suggest cells expressing AA-containing PI as potential targets for anti-cancer therapy. PMID:27435310

  4. BnWRI1 coordinates fatty acid biosynthesis and photosynthesis pathways during oil accumulation in rapeseed.

    PubMed

    Wu, Xue-Long; Liu, Zhi-Hong; Hu, Zhang-Hua; Huang, Rui-Zhi

    2014-06-01

    Photosynthesis in "green" seeds, such as rapeseed, soybean, and Arabidopsis, plays a substantial role in the improved efficiency of oil accumulation. However, the molecular mechanism underpinning the coordinated expression of fatty acid (FA) biosynthesis- and photosynthesis-related genes in such developing seeds remains to be elucidated. Here, we found that seed-specific overexpression of BnWRI1, a WRI1 homolog from rapeseed (Brassica napus cv. ZGY2), results in enhanced chlorophyll content in developing seeds and increased oil content and seed mass in matured seeds. BnWRI1 was co-expressed with BnBCCP and BnCAB, two marker genes of FA biosynthesis and photosynthesis during seed development, respectively. Overexpression of BnWRI1 increased expression of both marker genes. Further, the nuclear-localized BnWRI1 protein was found to act as a transcription activator. It could bind to the GT1-element and/or GCC-box, which are widespread in the upstream regions of genes involved in FA biosynthesis and photosynthesis pathways. Accordingly, BnWRI1 could interact with promoters of BCCP2 and LHB1B2 in vivo. These results suggested that BnWRI1 may coordinate FA biosynthesis and photosynthesis pathways in developing seeds via directly stimulating expression of GT1-element and/or GCC-box containing genes.

  5. Long-term accumulation of diphenylarsinic acid in the central nervous system of cynomolgus monkeys.

    PubMed

    Masuda, Tomoyuki; Ishii, Kazuhiro; Seto, Yasuo; Hosoya, Tomoko; Tanaka, Ryuta; Nakayama, Tomohiro; Iwasaki, Nobuaki; Shibata, Yasuyuki; Tamaoka, Akira

    2017-01-25

    Diphenylarsinic acid (DPAA) is an organic arsenic compound used for the synthesis of chemical weapons. We previously found that the residents of Kamisu city in Ibaraki Prefecture, Japan, were exposed to DPAA through contaminated well water in 2003. Although mounting evidence strongly suggests that their neurological symptoms were caused by DPAA, the dynamics of DPAA distribution and metabolism after ingestion by humans remain to be elucidated. To accurately predict the distribution of DPAA in the human body, we administrated DPAA (1.0 mg/kg/day) to cynomolgus monkeys (n = 28) for 28 days. The whole tissues from these monkeys were collected at 5, 29, 170, and 339 days after the last administration. The concentration of DPAA in these tissues was measured by liquid chromatography-mass spectrometry. We found that DPAA accumulated in the central nervous system tissues for a longer period than in other tissues. This finding would extend our knowledge on the distribution dynamics and metabolism of DPAA in primates, including humans. Furthermore, it may be useful for developing a treatment strategy for patients who are exposed to DPAA.

  6. Accumulation of free amino acids during exposure to drought in three springtail species.

    PubMed

    Holmstrup, Martin; Slotsbo, Stine; Rozsypal, Jan; Henriksen, Per G; Bayley, Mark

    2015-11-01

    Springtails are closely related to insects, but they differ from these with respect to water balance, in particular because springtails are small and have high integumental permeability to water. Here we report a series of experiments addressing the dynamics of osmoregulation, water content and accumulation of free amino acids (FAAs) in three springtail species during exposure to a gradually increasing environmental desiccation simulating conditions in drought exposed soil. Folsomia candida and Protaphorura fimata (both living in the deeper soil layers; euedaphic species) were active throughout the 3week exposure, with the developing drought regime ending at -3.56MPa (the soil water activity at the permanent wilting point of plants is -1.5MPa) and remained hyperosmotic (having an body fluid osmolality higher than the corresponding environment) to their surrounding air. Sinella curviseta (living in upper soil/litter layers; hemiedaphic species) also survived this exposure, but remained hypoosmotic throughout (i.e. with lower osmolality than the environment). The body content of most FAAs increased in response to drought in all three species. Alanine, proline and arginine were the most significantly upregulated FAAs. By combining our results with data in the literature, we could account for 82% of the observed osmolality at -3.56MPa in F. candida and 92% in P. fimata. The osmolality of S. curviseta was only slightly increased under drought, but here FAAs were considerably more important as osmolytes than in the two other species. We propose that FAAs probably have general importance in drought tolerance of springtails.

  7. Engineering alfalfa to accumulate useful caffeic acid derivatives and characterization of hydroxycinnamoyl-CoA transferases from legumes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some forages crops, such as red clover, accumulate high levels of caffeic acid derivatives. Oxidation of these o-diphenols to quinones by endogenous polyphenol oxidases (PPOs) and the subsequent reactions of these quinones (probably with endogenous plant proteases) result in a significant reduction ...

  8. Dynamic changes in the distribution of minerals in relation to phytic acid accumulation during rice seed development.

    PubMed

    Iwai, Toru; Takahashi, Michiko; Oda, Koshiro; Terada, Yasuko; Yoshida, Kaoru T

    2012-12-01

    Phytic acid (inositol hexakisphosphate [InsP(6)]) is the storage compound of phosphorus in seeds. As phytic acid binds strongly to metallic cations, it also acts as a storage compound of metals. To understand the mechanisms underlying metal accumulation and localization in relation to phytic acid storage, we applied synchrotron-based x-ray microfluorescence imaging analysis to characterize the simultaneous subcellular distribution of some mineral elements (phosphorus, calcium, potassium, iron, zinc, and copper) in immature and mature rice (Oryza sativa) seeds. This fine-imaging method can reveal whether these elements colocalize. We also determined their accumulation patterns and the changes in phosphate and InsP(6) contents during seed development. While the InsP(6) content in the outer parts of seeds rapidly increased during seed development, the phosphate contents of both the outer and inner parts of seeds remained low. Phosphorus, calcium, potassium, and iron were most abundant in the aleurone layer, and they colocalized throughout seed development. Zinc was broadly distributed from the aleurone layer to the inner endosperm. Copper localized outside the aleurone layer and did not colocalize with phosphorus. From these results, we suggest that phosphorus translocated from source organs was immediately converted to InsP(6) and accumulated in aleurone layer cells and that calcium, potassium, and iron accumulated as phytic acid salt (phytate) in the aleurone layer, whereas zinc bound loosely to InsP(6) and accumulated not only in phytate but also in another storage form. Copper accumulated in the endosperm and may exhibit a storage form other than phytate.

  9. Metformin reduces lipid accumulation in macrophages by inhibiting FOXO1-mediated transcription of fatty acid-binding protein 4

    SciTech Connect

    Song, Jun; Ren, Pingping; Zhang, Lin; Wang, Xing Li; Chen, Li; Shen, Ying H.

    2010-02-26

    Objective: The accumulation of lipids in macrophages contributes to the development of atherosclerosis. Strategies to reduce lipid accumulation in macrophages may have therapeutic potential for preventing and treating atherosclerosis and cardiovascular complications. The antidiabetic drug metformin has been reported to reduce lipid accumulation in adipocytes. In this study, we examined the effects of metformin on lipid accumulation in macrophages and investigated the mechanisms involved. Methods and results: We observed that metformin significantly reduced palmitic acid (PA)-induced intracellular lipid accumulation in macrophages. Metformin promoted the expression of carnitine palmitoyltransferase I (CPT-1), while reduced the expression of fatty acid-binding protein 4 (FABP4) which was involved in PA-induced lipid accumulation. Quantitative real-time PCR showed that metformin regulates FABP4 expression at the transcriptional level. We identified forkhead transcription factor FOXO1 as a positive regulator of FABP4 expression. Inhibiting FOXO1 expression with FOXO1 siRNA significantly reduced basal and PA-induced FABP4 expression. Overexpression of wild-type FOXO1 and constitutively active FOXO1 significantly increased FABP4 expression, whereas dominant negative FOXO1 dramatically decreased FABP4 expression. Metformin reduced FABP4 expression by promoting FOXO1 nuclear exclusion and subsequently inhibiting its activity. Conclusions: Taken together, these results suggest that metformin reduces lipid accumulation in macrophages by repressing FOXO1-mediated FABP4 transcription. Thus, metformin may have a protective effect against lipid accumulation in macrophages and may serve as a therapeutic agent for preventing and treating atherosclerosis in metabolic syndrome.

  10. Regulation of beta-galactoside transport and accumulation in heterofermentative lactic acid bacteria.

    PubMed Central

    Romano, A H; Brino, G; Peterkofsky, A; Reizer, J

    1987-01-01

    Galactose-grown cells of the heterofermentative lactic acid bacteria Lactobacillus brevis and Lactobacillus buchneri transported methyl-beta-D-thiogalactopyranoside (TMG) by an active transport mechanism and accumulated intracellular free TMG when provided with an exogenous source of energy, such as arginine. The intracellular concentration of TMG resultant under these conditions was approximately 20-fold higher than that in the medium. In contrast, the provision of energy by metabolism of glucose, gluconate, or glucosamine promoted a rapid but transient uptake of TMG followed by efflux that established a low cellular concentration of the galactoside, i.e., only two- to fourfold higher than that in the medium. Furthermore, the addition of glucose to cells preloaded with TMG in the presence of arginine elicited a rapid efflux of the intracellular galactoside. The extent of cellular TMG displacement and the duration of the transient effect of glucose on TMG transport were related to the initial concentration of glucose in the medium. Exhaustion of glucose from the medium restored uptake and accumulation of TMG, providing arginine was available for ATP generation. The nonmetabolizable sugar 2-deoxyglucose elicited efflux of TMG from preloaded cells of L. buchneri but not from those of L. brevis. Phosphorylation of this glucose analog was catalyzed by cell extracts of L. buchneri but not by those of L. brevis. Iodoacetate, at a concentration that inhibits growth and ATP production from glucose, did not prevent efflux of cellular TMG elicited by glucose. The results suggested that a phosphorylated metabolite(s) at or above the level of glyceraldehyde-3-phosphate was required to evoke displacement of intracellular TMG from the cells. Counterflow experiments suggested that glucose converted the active uptake of TMG in L. brevis to a facilitated diffusion mechanism that allowed equilibrium of TMG between the extra- and intracellular milieux. The means by which glucose

  11. Medium-chain fatty acid nanoliposomes suppress body fat accumulation in mice.

    PubMed

    Liu, Wei-Lin; Liu, Wei; Liu, Cheng-Mei; Yang, Shui-Bing; Liu, Jian-Hua; Zheng, Hui-Juan; Su, Kun-Ming

    2011-11-01

    Medium-chain fatty acids (MCFA) are widely used in diets for patients with obesity. To develop a delivery system for suppressing dietary fat accumulation into adipose tissue, MCFA were encapsulated in nanoliposomes (NL), which can overcome the drawbacks of MCFA and keep their properties unchanged. In the present study, crude liposomes were first produced by the thin-layer dispersion method, and then dynamic high-pressure microfluidisation (DHPM) and DHPM combined with freeze-thawing methods were used to prepare MCFA NL (NL-1 and NL-2, respectively). NL-1 exhibited smaller average size (77.6 (SD 4.3) nm), higher zeta potential (- 40.8 (SD 1.7) mV) and entrapment efficiency (73.3 (SD 16.1) %) and better stability, while NL-2 showed narrower distribution (polydispersion index 0.193 (SD 0.016)). The body fat reduction property of NL-1 and NL-2 were evaluated by short-term (2 weeks) and long-term (6 weeks) experiments of mice. In contrast to the MCFA group, the NL groups had overcome the poor palatability of MCFA because the normal diet of mice was maintained. The body fat and total cholesterol (TCH) of NL-1 (1.54 (SD 0.30) g, P = 0.039 and 2.33 (SD 0.44) mmol/l, P = 0.021, respectively) and NL-2 (1.58 (SD 0.69) g, P = 0.041 and 2.29 (SD 0.38) mmol/l, P = 0.015, respectively) significantly decreased when compared with the control group (2.11 (SD 0.82) g and 2.99 (SD 0.48) mmol/l, respectively). The TAG concentration of the NL-1 group (0.55 (SD 0.14) mmol/l) was remarkably lower (P = 0.045) than the control group (0.94 (SD 0.37) mmol/l). No significant difference in weight and fat gain, TCH and TAG was detected between the MCFA NL and MCFA groups. Therefore, MCFA NL could be potential nutritional candidates for obesity to suppress body fat accumulation.

  12. Effects of Fatty Acid Quality and Quantity in the Japanese Diet on the Suppression of Lipid Accumulation.

    PubMed

    Sakamoto, Yu; Yamamoto, Kazushi; Hatakeyama, Yu; Tsuduki, Tsuyoshi

    2016-01-01

    Japan has been known as a healthy country since its life expectancy became among the highest in the world in the 1980s. The influence of the Japanese diet is one of the factors explaining Japan's high life expectancy. Our recent study that fed representative freeze-dried and powdered Japanese diets from 1960, 1975, 1990, and 2005 based on National Health and Nutrition Research to mice showed the 1975 Japanese diet exhibited the strongest visceral fat accumulation suppression and overall health benefits. However, it is unclear why. We investigated the effects of the fatty acid composition in Japanese diets on visceral fat accumulation in mice. ICR mice were fed diets replicating the fatty acid composition and macronutrient ratios of Japanese diets from 1960, 1975, 1990, and 2005 for four weeks. The 1975 diet suppressed visceral fat accumulation and adipocyte hypertrophy. DNA microarray analysis showed the 1975 diet suppressed Acyl-CoA synthetase and prostaglandin D2 synthase mRNA expressions in white adipose tissue. As the effects of the 1975 diet are likely due to differences in fatty acid intake and/or composition, we investigated test diets that replicated only the fatty acid composition of Japanese diets. There were no significant differences in visceral fat mass. Therefore, both the quality and quantity of fatty acids are involved in the anti-obesity effects of the 1975 Japanese diet.

  13. Accumulation of very-long-chain fatty acids in membrane glycerolipids is associated with dramatic alterations in plant morphology.

    PubMed Central

    Millar, A A; Wrischer, M; Kunst, L

    1998-01-01

    Transgenic Arabidopsis plants overexpressing the Arabidopsis FATTY ACID ELONGATION1 gene under the control of the 35S promoter from cauliflower mosaic virus accumulated very-long-chain fatty acids (VLCFAs) throughout the plant. In some transformants, C20 and C22 VLCFAs accounted for >30% of the total fatty acids, accumulating at the expense of C16 and C18 fatty acids. These C20 and C22 fatty acids were incorporated into all of the major membrane glycerolipid classes. Plants with a high VLCFA content displayed a dramatically altered morphology, which included the failure of flowering shoots to elongate, a modified spatial pattern of siliques, an altered floral phenotype, and a large accumulation of anthocyanins. In addition, these plants also exhibited a unique alteration of the chloroplast membrane structure. We discuss a possible role for VLCFAs in establishing the shape/curvature of the membranes, which in turn may affect the shape of the cell and ultimately that of the whole plant. PMID:9811796

  14. Ophthalmic acid accumulation in an Escherichia coli mutant lacking the conserved pyridoxal 5'-phosphate-binding protein YggS.

    PubMed

    Ito, Tomokazu; Yamauchi, Ayako; Hemmi, Hisashi; Yoshimura, Tohru

    2016-12-01

    Escherichia coli YggS is a highly conserved pyridoxal 5'-phosphate (PLP)-binding protein whose biochemical function is currently unknown. A previous study with a yggS-deficient E. coli strain (ΔyggS) demonstrated that YggS controls l-Ile- and l-Val-metabolism by modulating 2-ketobutyrate (2-KB), l-2-aminobutyrate (l-2-AB), and/or coenzyme A (CoA) availability in a PLP-dependent fashion. In this study, we found that ΔyggS accumulates an unknown metabolite as judged by amino acid analyses. LC/MS and MS/MS analyses of the compound with propyl chloroformate derivatization, and co-chromatography analysis identified this compound as γ-l-glutamyl-l-2-aminobutyryl-glycine (ophthalmic acid), a glutathione (GSH) analogue in which the l-Cys moiety is replaced by l-2-AB. We also determine the metabolic consequence of the yggS mutation. Absence of YggS initially increases l-2-AB availability, and then causes ophthalmic acid accumulation and CoA limitation in the cell. The expression of a γ-glutamylcysteine synthetase and a glutathione synthetase in a ΔyggS background causes high-level accumulation of ophthalmic acid in the cells (∼1.2 nmol/mg cells) in a minimal synthetic medium. This opens the possibility of a first fermentative production of ophthalmic acid.

  15. Regulation of Primary Metabolic Pathways in Oyster Mushroom Mycelia Induced by Blue Light Stimulation: Accumulation of Shikimic Acid

    PubMed Central

    Kojima, Masanobu; Kimura, Ninako; Miura, Ryuhei

    2015-01-01

    Shikimic acid is a key intermediate in the aromatic amino acid pathway as well as an important starting material for the synthesis of Tamiflu, a potent and selective inhibitor of the neuraminidase enzyme of influenza viruses A and B. Here we report that in oyster mushroom (Pleurotus ostreatus) mycelia cultivated in the dark, stimulation with blue light-emitting diodes induces the accumulation of shikimic acid. An integrated analysis of primary metabolites, gene expression and protein expression suggests that the accumulation of shikimic acid caused by blue light stimulation is due to an increase in 3-deoxy-D-arabinoheptulosonate 7-phosphate synthase (DAHPS, EC2.5.1.54), the rate-determining enzyme in the shikimic acid pathway, as well as phosphofructokinase (PFK, EC2.7.1.11) and glucose-6-phosphate dehydrogenase (G6PD, EC1.1.1.49), the rate-determining enzymes in the glycolysis and pentose phosphate pathways, respectively. This stimulation results in increased levels of phosphoenolpyruvic acid (PEP) and erythrose-4-phosphate (E4P), the starting materials of shikimic acid biosynthesis. PMID:25721093

  16. Regulation of primary metabolic pathways in oyster mushroom mycelia induced by blue light stimulation: accumulation of shikimic acid.

    PubMed

    Kojima, Masanobu; Kimura, Ninako; Miura, Ryuhei

    2015-02-27

    Shikimic acid is a key intermediate in the aromatic amino acid pathway as well as an important starting material for the synthesis of Tamiflu, a potent and selective inhibitor of the neuraminidase enzyme of influenza viruses A and B. Here we report that in oyster mushroom (Pleurotus ostreatus) mycelia cultivated in the dark, stimulation with blue light-emitting diodes induces the accumulation of shikimic acid. An integrated analysis of primary metabolites, gene expression and protein expression suggests that the accumulation of shikimic acid caused by blue light stimulation is due to an increase in 3-deoxy-D-arabinoheptulosonate 7-phosphate synthase (DAHPS, EC2.5.1.54), the rate-determining enzyme in the shikimic acid pathway, as well as phosphofructokinase (PFK, EC2.7.1.11) and glucose-6-phosphate dehydrogenase (G6PD, EC1.1.1.49), the rate-determining enzymes in the glycolysis and pentose phosphate pathways, respectively. This stimulation results in increased levels of phosphoenolpyruvic acid (PEP) and erythrose-4-phosphate (E4P), the starting materials of shikimic acid biosynthesis.

  17. The expression of the Cuphea palustris thioesterase CpFatB2 in Yarrowia lipolytica triggers oleic acid accumulation.

    PubMed

    Stefan, Alessandra; Hochkoeppler, Alejandro; Ugolini, Luisa; Lazzeri, Luca; Conte, Emanuele

    2016-01-01

    The conversion of industrial by-products into high-value added compounds is a challenging issue. Crude glycerol, a by-product of the biodiesel production chain, could represent an alternative carbon source for the cultivation of oleaginous yeasts. Here, we developed five minimal synthetic glycerol-based media, with different C/N ratios, and we analyzed the production of biomass and fatty acids by Yarrowia lipolytica Po1g strain. We identified two media at the expense of which Y. lipolytica was able to accumulate ∼5 g L(-1) of biomass and 0.8 g L(-1) of fatty acids (0.16 g of fatty acids per g of dry weight). These optimized media contained 0.5 g L(-1) of urea or ammonium sulfate and 20 g L(-1) of glycerol, and were devoid of yeast extract. Moreover, Y. lipolytica was engineered by inserting the FatB2 gene, coding for the CpFatB2 thioesterase from Cuphea palustris, in order to modify the fatty acid composition towards the accumulation of medium-chain fatty acids. Contrary to the expected, the expression of the heterologous gene increased the production of oleic acid, and concomitantly decreased the level of saturated fatty acids.

  18. Metabolism of organic acids, nitrogen and amino acids in chlorotic leaves of 'Honeycrisp' apple (Malus domestica Borkh) with excessive accumulation of carbohydrates.

    PubMed

    Wang, Huicong; Ma, Fangfang; Cheng, Lailiang

    2010-07-01

    Metabolite profiles and activities of key enzymes in the metabolism of organic acids, nitrogen and amino acids were compared between chlorotic leaves and normal leaves of 'Honeycrisp' apple to understand how accumulation of non-structural carbohydrates affects the metabolism of organic acids, nitrogen and amino acids. Excessive accumulation of non-structural carbohydrates and much lower CO(2) assimilation were found in chlorotic leaves than in normal leaves, confirming feedback inhibition of photosynthesis in chlorotic leaves. Dark respiration and activities of several key enzymes in glycolysis and tricarboxylic acid (TCA) cycle, ATP-phosphofructokinase, pyruvate kinase, citrate synthase, aconitase and isocitrate dehydrogenase were significantly higher in chlorotic leaves than in normal leaves. However, concentrations of most organic acids including phosphoenolpyruvate (PEP), pyruvate, oxaloacetate, 2-oxoglutarate, malate and fumarate, and activities of key enzymes involved in the anapleurotic pathway including PEP carboxylase, NAD-malate dehydrogenase and NAD-malic enzyme were significantly lower in chlorotic leaves than in normal leaves. Concentrations of soluble proteins and most free amino acids were significantly lower in chlorotic leaves than in normal leaves. Activities of key enzymes in nitrogen assimilation and amino acid synthesis, including nitrate reductase, glutamine synthetase, ferredoxin and NADH-dependent glutamate synthase, and glutamate pyruvate transaminase were significantly lower in chlorotic leaves than in normal leaves. It was concluded that, in response to excessive accumulation of non-structural carbohydrates, glycolysis and TCA cycle were up-regulated to "consume" the excess carbon available, whereas the anapleurotic pathway, nitrogen assimilation and amino acid synthesis were down-regulated to reduce the overall rate of amino acid and protein synthesis.

  19. Point mutation of the xylose reductase (XR) gene reduces xylitol accumulation and increases citric acid production in Aspergillus carbonarius.

    PubMed

    Weyda, István; Lübeck, Mette; Ahring, Birgitte K; Lübeck, Peter S

    2014-04-01

    Aspergillus carbonarius accumulates xylitol when it grows on D-xylose. In fungi, D-xylose is reduced to xylitol by the NAD(P)H-dependent xylose reductase (XR). Xylitol is then further oxidized by the NAD(+)-dependent xylitol dehydrogenase (XDH). The cofactor impairment between the XR and XDH can lead to the accumulation of xylitol under oxygen-limiting conditions. Most of the XRs are NADPH dependent and contain a conserved Ile-Pro-Lys-Ser motif. The only known naturally occurring NADH-dependent XR (from Candida parapsilosis) carries an arginine residue instead of the lysine in this motif. In order to overcome xylitol accumulation in A. carbonarius a Lys-274 to Arg point mutation was introduced into the XR with the aim of changing the specificity toward NADH. The effect of the genetic engineering was examined in fermentation for citric acid production and xylitol accumulation by using D-xylose as the sole carbon source. Fermentation with the mutant strain showed a 2.8-fold reduction in xylitol accumulation and 4.5-fold increase in citric acid production compared to the wild-type strain. The fact that the mutant strain shows decreased xylitol levels is assumed to be associated with the capability of the mutated XR to use the NADH generated by the XDH, thus preventing the inhibition of XDH by the high levels of NADH and ensuring the flux of xylose through the pathway. This work shows that enhanced production of citric acid can be achieved using xylose as the sole carbon source by reducing accumulation of other by-products, such as xylitol.

  20. Jasmonic Acid and Its Precursor 12-Oxophytodienoic Acid Control Different Aspects of Constitutive and Induced Herbivore Defenses in Tomato1[W][OPEN

    PubMed Central

    Bosch, Marko; Wright, Louwrance P.; Gershenzon, Jonathan; Wasternack, Claus; Hause, Bettina; Schaller, Andreas; Stintzi, Annick

    2014-01-01

    The jasmonate family of growth regulators includes the isoleucine (Ile) conjugate of jasmonic acid (JA-Ile) and its biosynthetic precursor 12-oxophytodienoic acid (OPDA) as signaling molecules. To assess the relative contribution of JA/JA-Ile and OPDA to insect resistance in tomato (Solanum lycopersicum), we silenced the expression of OPDA reductase3 (OPR3) by RNA interference (RNAi). Consistent with a block in the biosynthetic pathway downstream of OPDA, OPR3-RNAi plants contained wild-type levels of OPDA but failed to accumulate JA or JA-Ile after wounding. JA/JA-Ile deficiency in OPR3-RNAi plants resulted in reduced trichome formation and impaired monoterpene and sesquiterpene production. The loss of these JA/JA-Ile -dependent defense traits rendered them more attractive to the specialist herbivore Manduca sexta with respect to feeding and oviposition. Oviposition preference resulted from reduced levels of repellant monoterpenes and sesquiterpenes. Feeding preference, on the other hand, was caused by increased production of cis-3-hexenal acting as a feeding stimulant for M. sexta larvae in OPR3-RNAi plants. Despite impaired constitutive defenses and increased palatability of OPR3-RNAi leaves, larval development was indistinguishable on OPR3-RNAi and wild-type plants, and was much delayed compared with development on the jasmonic acid-insensitive1 (jai1) mutant. Apparently, signaling through JAI1, the tomato ortholog of the ubiquitin ligase CORONATINE INSENSITIVE1 in Arabidopsis (Arabidopsis thaliana), is required for defense, whereas the conversion of OPDA to JA/JA-Ile is not. Comparing the signaling activities of OPDA and JA/JA-Ile, we found that OPDA can substitute for JA/JA-Ile in the local induction of defense gene expression, but the production of JA/JA-Ile is required for a systemic response. PMID:25073705

  1. Jasmonic acid-isoleucine formation in grapevine (Vitis vinifera L.) by two enzymes with distinct transcription profiles.

    PubMed

    Böttcher, Christine; Burbidge, Crista A; di Rienzo, Valentina; Boss, Paul K; Davies, Christopher

    2015-07-01

    The plant hormone jasmonic acid (JA) is essential for stress responses and the formation of reproductive organs, but its role in fruit development and ripening is unclear. Conjugation of JA to isoleucine is a crucial step in the JA signaling pathway since only JA-Ile is recognized by the jasmonate receptor. The conjugation reaction is catalyzed by JA-amido synthetases, belonging to the family of Gretchen Hagen3 (GH3) proteins. Here, in vitro studies of two grapevine (Vitis vinifera L. cv Shiraz) GH3 enzymes, VvGH3-7 and VvGH3-9, demonstrated JA-conjugating activities with an overlapping range of amino acid substrates, including isoleucine. Expression studies of the corresponding genes in grape berries combined with JA and JA-Ile measurements suggested a primary role for JA signaling in fruit set and cell division and did not support an involvement of JA in the ripening process. In response to methyl JA (MeJA) treatment, and in wounded and unwounded (distal) leaves, VvGH3-9 transcripts accumulated, indicating a participation in the JA response. In contrast, VvGH3-7 was unresponsive to MeJA and local wounding, demonstrating a differential transcriptional regulation of VvGH3-7 and VvGH3-9. The transient induction of VvGH3-7 in unwounded, distal leaves was suggestive of the involvement of an unknown mobile wound signal.

  2. A survey of mangiferin and hydroxycinnamic acid ester accumulation in coffee (Coffea) leaves: biological implications and uses

    PubMed Central

    Campa, Claudine; Mondolot, Laurence; Rakotondravao, Arsene; Bidel, Luc P. R.; Gargadennec, Annick; Couturon, Emmanuel; La Fisca, Philippe; Rakotomalala, Jean-Jacques; Jay-Allemand, Christian; Davis, Aaron P.

    2012-01-01

    Background and Aims The phenolic composition of Coffea leaves has barely been studied, and therefore this study conducts the first detailed survey, focusing on mangiferin and hydroxycinnamic acid esters (HCEs). Methods Using HPLC, including a new technique allowing quantification of feruloylquinic acid together with mangiferin, and histochemical methods, mangiferin content and tissue localization were compared in leaves and fruits of C. pseudozanguebariae, C. arabica and C. canephora. The HCE and mangiferin content of leaves was evaluated for 23 species native to Africa or Madagascar. Using various statistical methods, data were assessed in relation to distribution, ecology, phylogeny and use. Key Results Seven of the 23 species accumulated mangiferin in their leaves. Mangiferin leaf-accumulating species also contain mangiferin in the fruits, but only in the outer (sporophytic) parts. In both leaves and fruit, mangiferin accumulation decreases with ageing. A relationship between mangiferin accumulation and UV levels is posited, owing to localization with photosynthetic tissues, and systematic distribution in high altitude clades and species with high altitude representatives. Analyses of mangiferin and HCE content showed that there are significant differences between species, and that samples can be grouped into species, with few exceptions. These data also provide independent support for various Coffea lineages, as proposed by molecular phylogenetic analyses. Sampling of the hybrids C. arabica and C. heterocalyx cf. indicates that mangiferin and HCE accumulation may be under independent parental influence. Conclusions This survey of the phenolic composition in Coffea leaves shows that mangiferin and HCE accumulation corresponds to lineage recognition and species delimitation, respectively. Knowledge of the spectrum of phenolic accumulation within species and populations could be of considerable significance for adaptation to specific environments. The potential

  3. Sweating treatment enhances citrus fruit disease resistance by inducing the accumulation of amino acids and salicylic acid-induced resistance pathway.

    PubMed

    Yun, Ze; Zhu, Feng; Liu, Ping; Zeng, Yunliu; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2015-04-20

    To clarify the mechanism of fruit disease resistance activated by sweating treatment, 'Guoqing NO.1' Satsuma mandarin (Citrus unshiu Marc.) fruits were treated by sweating, which is a traditional prestorage treatment in China. Subsequently, we performed inoculation and physiological characterization, two-dimensional gel electrophoresis (2-DE) proteomics analysis and metabonomics analysis based on gas chromatography coupled to mass spectrometry (GC-MS) and high-performance liquid chromatography/electrospray ionization-time of flight-mass spectrometry (HPLC-qTOF-MS). The results showed that sweating treatment significantly inhibited pathogen infection without negatively affecting the fruit commercial quality. In addition, sweating treatment rapidly promoted the accumulation of amino acids (such as proline and serine). Meanwhile, hydrogen peroxide (H2 O2 ) and salicylic acid (SA) were significantly accumulated in the sweating-treated fruit. Thereafter, some stress-response proteins and metabolites [such as ascorbate peroxidase (APX), β-1,3-glucanase, vanillic acid and rutin] which can be induced by SA were also significantly increased in the sweating-treated fruit. Taken together, the disease resistance induced by sweating treatment might be attributed to: (1) the induction of the accumulation of amino acids; and (2) the accumulation of SA and subsequent activation of SA-induced resistance pathway, which can induce the stress-response proteins and metabolites that can directly inhibit pathogen development.

  4. Oxaloacetate acetylhydrolase gene mutants of Sclerotinia sclerotiorum do not accumulate oxalic acid, but do produce limited lesions on host plants.

    PubMed

    Liang, Xiaofei; Liberti, Daniele; Li, Moyi; Kim, Young-Tae; Hutchens, Andrew; Wilson, Ron; Rollins, Jeffrey A

    2015-08-01

    The oxaloacetate acetylhydrolase (OAH, EC 3.7.1.1)-encoding gene Ss-oah1 was cloned and functionally characterized from Sclerotinia sclerotiorum. Ss-oah1 transcript accumulation mirrored oxalic acid (OA) accumulation with neutral pH induction dependent on the pH-responsive transcriptional regulator Ss-Pac1. Unlike previously characterized ultraviolet (UV)-induced oxalate-deficient mutants ('A' mutants) which retain the capacity to accumulate OA, gene deletion Δss-oah1 mutants did not accumulate OA in culture or during plant infection. This defect in OA accumulation was fully restored on reintroduction of the wild-type (WT) Ss-oah1 gene. The Δss-oah1 mutants were also deficient in compound appressorium and sclerotium development and exhibited a severe radial growth defect on medium buffered at neutral pH. On a variety of plant hosts, the Δss-oah1 mutants established very restricted lesions in which the infectious hyphae gradually lost viability. Cytological comparisons of WT and Δss-oah1 infections revealed low and no OA accumulation, respectively, in subcuticular hyphae. Both WT and mutant hyphae exhibited a transient association with viable host epidermal cells at the infection front. In summary, our experimental data establish a critical requirement for OAH activity in S. sclerotiorum OA biogenesis and pathogenesis, but also suggest that factors independent of OA contribute to the establishment of primary lesions.

  5. Prey-induced changes in the accumulation of amino acids and phenolic metabolites in the leaves of Drosera capensis L.

    PubMed

    Kováčik, Jozef; Klejdus, Bořivoj; Stork, František; Hedbavny, Josef

    2012-04-01

    Effect of prey feeding (ants Formica fusca) on the quantitative changes in the accumulation of free amino acids, soluble proteins, phenolic metabolites and mineral nutrients in the leaves of carnivorous plant Drosera capensis was studied. Arginine was the most abundant compound in Drosera leaves, while proline was abundant in ants. The amount of the majority of amino acids and their sum were elevated in the fed leaves after 3 and 21 days, and the same, but with further enhancement after 21 days, was observed in ants. Accumulation of amino acids also increased in young non-fed leaves of fed plants. Soluble proteins decreased in ants, but were not enhanced in fed leaves. This confirms the effectiveness of sundew's enzymatic machinery in digestion of prey and suggests that amino acids are not in situ deposited, but rather are allocated within the plant. The content of total soluble phenols, flavonoids and two selected flavonols (quercetin and kaempferol) was not affected by feeding in Drosera leaves, indicating that their high basal level was sufficient for the plant's metabolism and prey-induced changes were mainly N based. The prey also showed to be an important source of other nutrients besides N, and a stimulation of root uptake of some mineral nutrients is assumed (Mg, Cu, Zn). Accumulation of Ca and Na was not affected by feeding.

  6. Accumulation of wound-inducible ACC synthase transcript in tomato fruit is inhibited by salicylic acid and polyamines.

    PubMed

    Li, N; Parsons, B L; Liu, D R; Mattoo, A K

    1992-02-01

    Regulation of wound-inducible 1-aminocyclopropane-1-carboxylic acid (ACC) synthase expression was studied in tomato fruit (Lycopersicon esculentum cv. Pik-Red). A 70 base oligonucleotide probe homologous to published ACC synthase cDNA sequences was successfully used to identify and analyze regulation of a wound-inducible transcript. The 1.8 kb ACC synthase transcript increased upon wounding the fruit as well as during fruit ripening. Salicylic acid, an inhibitor of wound-responsive genes in tomato, inhibited the wound-induced accumulation of the ACC synthase transcript. Further, polyamines (putrescine, spermidine and spermine) that have anti-senescence properties and have been shown to inhibit the development of ACC synthase activity, inhibited the accumulation of the wound-inducible ACC synthase transcript. The inhibition by spermine was greater than that caused by putrescine or spermidine. The transcript level of a wound-repressible glycine-rich protein gene and that of the constitutively expressed rRNA were not affected as markedly by either salicylic acid or polyamines. These data suggest that salicylic acid and polyamines may specifically regulate ethylene biosynthesis at the level of ACC synthase transcript accumulation.

  7. Roles of rhizosphere and root-derived organic acids in Cd accumulation by two hot pepper cultivars.

    PubMed

    Xin, Junliang; Huang, Baifei; Dai, Hongwen; Zhou, Wenjing; Yi, Yumei; Peng, Lijing

    2015-04-01

    Cultivars of hot pepper (Capsicum annuum L.) have different abilities to accumulate Cd in their fruits. Previously, we suggested that low-Cd cultivars take up more Cd, but can better prevent the Cd translocation from roots to aerial parts. However, the mechanisms involved in those processes are still unclear. In this study, we explored the roles of rhizosphere soil Cd fractions and root secretions of low molecular weight organic acids in the uptake, translocation, and accumulation of Cd in a low-Cd and high-Cd cultivar. The results showed that there was no significant difference in exchangeable Cd between rhizosphere soils of the two cultivars, which might be related to their similar root's Cd uptake ability. The total content of low molecular weight organic acids released from roots of the low-Cd cultivar was almost equal to that released from roots of the high-Cd cultivar at the same Cd level; however, the composition of low molecular weight organic acids were determined by cultivars and Cd exposure levels. In the higher Cd (10 μM) treatment, the roots of the low-Cd cultivar excreted significantly less tartaric acid and more oxalic and acetic acids than those of the high-Cd cultivar. Additionally, there was no difference in the concentration of citric or succinic acid between the two cultivars. These results indicate that some kinds of low molecular weight organic acids efflux from hot pepper roots played an important role in the difference of Cd accumulation between low- and high-Cd cultivars.

  8. Fatty acid rich effluent from acidogenic biohydrogen reactor as substrate for lipid accumulation in heterotrophic microalgae with simultaneous treatment.

    PubMed

    Venkata Mohan, S; Prathima Devi, M

    2012-11-01

    Acid-rich effluent generated from acidogenic biohydrogen production process was evaluated as substrate for lipid synthesis by integrating with heterotrophic cultivation of mixed microalgae. Experiments were performed both with synthetic volatile fatty acids (SVFA) and fermented fatty acids (FFA) from biohydrogen producing reactor. Fatty acid based platform evidenced significant influence on algal growth as well as lipid accumulation by the formation of triglycerides through fatty acid synthesis. Comparatively FFA documented higher biomass and lipid productivity (1.42mg/ml (wet weight); 26.4%) than SVFAs ((HAc+HBu+HPr), 0.60mg/ml; 23.1%). Lipid profiles varied with substrates and depicted 18 types of saturated and unsaturated fatty acids with wide fuel and food characteristics. The observed higher concentrations of Chl b over Chl a supports the biosynthesis of triacylglycerides. Microalgae diversity visualized the presence of lipid accumulating species viz., Scenedesmus sp. and Chlorella sp. Integration of microalgae cultivation with biohydrogen production showed lipid productivity for biodiesel production along with additional treatment.

  9. [Combined effects of copper and simulated acid rain on copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa].

    PubMed

    He, Shan-Ying; Gao, Yong-Jie; Shentu, Jia-Li; Chen, Kun-Bai

    2011-02-01

    A pot experiment was conducted to study the combined effects of Cu (0-1500 mg x kg(-1)) and simulated acid rain (pH 2.5-5.6) on the copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa. With the increasing concentration of soil Cu, the Cu accumulation in R. acetosa increased, being higher in root than in stem and leaf. The exposure to low pH acid rain promoted the Cu uptake by R. acetosa. With the increase of soil Cu concentration and/or of acid rain acidity, the biomass of R. acetosa decreased, leaf and root MDA contents increased and had good correlation with soil Cu concentration, and the SOD and POD activities in leaf and root displayed a decreasing trend after an initial increase. This study showed that R. acetosa had a strong adaptive ability to Cu and acid rain stress, exhibiting a high application potential in the remediation of Cu-contaminated soil in acid rain areas.

  10. Accumulation fatty acids of in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoA carboxylase, temperature, and co-immobilization with Azospirillum brasilense

    NASA Astrophysics Data System (ADS)

    Leyva, Luis A.; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E.

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.

  11. Reducing isozyme competition increases target fatty acid accumulation in seed triacylglycerols of transgenic Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One goal of green chemistry is the production of industrially useful fatty acids (FAs) in crop plants. We focus on the engineering of industrial FAs, specifically hydroxy fatty acids (HFA) and conjugated polyenoic fatty acids (a-eleostearic acid, ESA), using Arabidopsis (Arabidopsis thaliana) as a m...

  12. Exogenous malic and acetic acids reduce cadmium phytotoxicity and enhance cadmium accumulation in roots of sunflower plants.

    PubMed

    Hawrylak-Nowak, Barbara; Dresler, Sławomir; Matraszek, Renata

    2015-09-01

    There is increasing evidence showing that low molecular weight organic acids (LMWOA) are involved in heavy metal resistance mechanisms in plants. The aim of this study was to investigate the effects of exogenous malic (MA) or acetic (AA) acids on the toxicity and accumulation of cadmium (Cd) in sunflower (Helianthus annuus L.). For this purpose, plants were grown in hydroponics under controlled conditions. Single Cd stress (5 μM Cd for 14 days) induced strong phytotoxic effects, as indicated by a decrease in all growth parameters, concentration of photosynthetic pigments, and root activity, as well as a high level of hydrogen peroxide (H2O2) accumulation. Exogenous MA or AA (250 or 500 μM) applied to the Cd-containing medium enhanced the accumulation of Cd by the roots and limited Cd translocation to the shoots. Moreover, the MA or AA applied more or less reduced Cd phytotoxicity by increasing the growth parameters, photosynthetic pigment concentrations, decreasing accumulation of H2O2, and improving the root activity. Of the studied organic acids, MA was much more efficient in mitigation of Cd toxicity than AA, probably by its antioxidant effects, which were stronger than those of AA. Plant response to Cd involved decreased production of endogenous LMWOA, probably as a consequence of severe Cd toxicity. The addition of MA or AA to the medium increased endogenous accumulation of LMWOA, especially in the roots, which could be beneficial for plant metabolism. These results imply that especially MA may be involved in the processes of Cd uptake, translocation, and tolerance in plants.

  13. Dual effects of slightly acidic electrolyzed water (SAEW) treatment on the accumulation of γ-aminobutyric acid (GABA) and rutin in germinated buckwheat.

    PubMed

    Hao, Jianxiong; Wu, Tongjiao; Li, Huiying; Wang, Wei; Liu, Haijie

    2016-06-15

    In the present study, the dual effects of slightly acidic electrolyzed water (SAEW) treatment on γ-aminobutyric acid (GABA) and rutin accumulation of germinated buckwheat were evaluated during germination. The results showed that SAEW treatment (pH 5.83, ACC of 20.3 mg/L) could promote the accumulation of GABA and rutin in germinated buckwheat. The GABA and rutin contents of SAEW-germinated buckwheat reached 143.20 and 739.9 mg/100 g respectively, which is significantly higher than those of control (P<0.05). Moreover, SAEW treatment could increase the activity of glutamic acid decarboxylase (GAD) and phenylalanine ammonialyase (PAL) and thus result in the GABA and rutin accumulation of germinated buckwheat. The results suggested that SAEW treatment could promote the rutin accumulation of germinated buckwheat by influencing phenylpropanoid secondary metabolic pathway instead of the inhibition of rutin degrading enzyme (RDE) activity. In addition, SAEW treatment had no adverse impact on the sprouts growth and could reduce the microbial populations of germinated buckwheat during germination.

  14. Effects of waste activated sludge and surfactant addition on primary sludge hydrolysis and short-chain fatty acids accumulation.

    PubMed

    Ji, Zhouying; Chen, Guanlan; Chen, Yinguang

    2010-05-01

    This paper focused on the effects of waste activated sludge (WAS) and surfactant sodium dodecylbenzene sulfonate (SDBS) addition on primary sludge (PS) hydrolysis and short-chain fatty acids (SCFA) accumulation in fermentation. The results showed that sludge hydrolysis, SCFA accumulation, NH(4)(+)-N and PO(4)(3-)-P release, and volatile suspended solids (VSS) reduction were increased by WAS addition to PS, which were further increased by the addition of SDBS to the mixture of PS and WAS. Acetic, propionic and valeric acids were the top three SCFA in all experiments. Also, the fermentation liquids of PS, PS+WAS, and PS+WAS+SDBS were added, respectively, to municipal wastewater to examine their effects on biological municipal wastewater treatment, and the enhancement of both wastewater nitrogen and phosphorus removals was observed compared with no fermentation liquid addition.

  15. Mechanism of Arachidonic Acid Accumulation during Aging in Mortierella alpina: A Large-Scale Label-Free Comparative Proteomics Study.

    PubMed

    Yu, Yadong; Li, Tao; Wu, Na; Ren, Lujing; Jiang, Ling; Ji, Xiaojun; Huang, He

    2016-11-30

    Arachidonic acid (ARA) is an important polyunsaturated fatty acid having various beneficial physiological effects on the human body. The aging of Mortierella alpina has long been known to significantly improve ARA yield, but the exact mechanism is still elusive. Herein, multiple approaches including large-scale label-free comparative proteomics were employed to systematically investigate the mechanism mentioned above. Upon ultrastructural observation, abnormal mitochondria were found to aggregate around shrunken lipid droplets. Proteomics analysis revealed a total of 171 proteins with significant alterations of expression during aging. Pathway analysis suggested that reactive oxygen species (ROS) were accumulated and stimulated the activation of the malate/pyruvate cycle and isocitrate dehydrogenase, which might provide additional NADPH for ARA synthesis. EC 4.2.1.17-hydratase might be a key player in ARA accumulation during aging. These findings provide a valuable resource for efforts to further improve the ARA content in the oil produced by aging M. alpina.

  16. Accumulation of Rutin and Betulinic Acid and Expression of Phenylpropanoid and Triterpenoid Biosynthetic Genes in Mulberry (Morus alba L.).

    PubMed

    Zhao, Shicheng; Park, Chang Ha; Li, Xiaohua; Kim, Yeon Bok; Yang, Jingli; Sung, Gyoo Byung; Park, Nam Il; Kim, Soonok; Park, Sang Un

    2015-09-30

    Mulberry (Morus alba L.) is used in traditional Chinese medicine and is the sole food source of the silkworm. Here, 21 cDNAs encoding phenylpropanoid biosynthetic genes and 21 cDNAs encoding triterpene biosynthetic genes were isolated from mulberry. The expression levels of genes involved in these biosynthetic pathways and the accumulation of rutin, betulin, and betulinic acid, important secondary metabolites, were investigated in different plant organs. Most phenylpropanoid and triterpene biosynthetic genes were highly expressed in leaves and/or fruit, and most genes were downregulated during fruit ripening. The accumulation of rutin was more than fivefold higher in leaves than in other organs, and higher levels of betulin and betulinic acid were found in roots and leaves than in fruit. By comparing the contents of these compounds with gene expression levels, we speculate that MaUGT78D1 and MaLUS play important regulatory roles in the rutin and betulin biosynthetic pathways.

  17. Naturally evolved enhanced Cd tolerance of Dianthus carthusianorum L. is not related to accumulation of thiol peptides and organic acids.

    PubMed

    Wójcik, Małgorzata; Dresler, Sławomir; Plak, Andrzej; Tukiendorf, Anna

    2015-05-01

    Two contrasting ecotypes of Dianthus carthusianorum L., metallicolous (M) and nonmetallicolous (NM), were cultivated in hydroponics at 0-50 μM Cd for 14 days to compare their Cd accumulation, sensitivity and tolerance mechanisms. While both ecotypes contained similar concentrations of Cd in the shoots and roots, the M ecotype was more Cd-tolerant (as measured by fresh weight production and root and leaf viability). Both ecotypes accumulated phytochelatins (PCs) in response to Cd with a higher amount thereof found in the NM ecotype. Concentrations of PCs remained unchanged with increasing Cd concentrations in the root tissues, but their content in the shoots increased. The addition of L-buthionine-sulfoximine (BSO) diminished glutathione (GSH) accumulation and arrested PC production, which increased the sensitivity to Cd of the NM, but not M ecotype. Organic acids (malate and citrate) as well as proline accumulation did not change significantly after Cd exposition and was at the same level in both ecotypes. The enhanced Cd tolerance of the M ecotype of D. carthusianorum cannot be explained in terms of restricted Cd uptake and differential production of PCs, organic acids or proline; some other mechanisms must be involved in its adaptation to the high Cd content in the environment.

  18. Swertiamarin ameliorates oleic acid induced lipid accumulation and oxidative stress by attenuating gluconeogenesis and lipogenesis in hepatic steatosis.

    PubMed

    Patel, Tushar P; Rawal, Komal; Soni, Sanket; Gupta, Sarita

    2016-10-01

    Swertiamarin, a bitter secoiridoid glycoside, is an antidiabetic drug with lipid lowering activity meliorates insulin resistance in Type 2 Diabetes condition. Therefore, the study was designed to explore the antioxidant and hypolipidemic activity of swertiamarin in ameliorating NAFLD caused due to hepatic lipid accumulation, inflammation and insulin resistance. Steatosis was induced in HepG2 cells by supplementing 1mM oleic acid (OA) for 24h which was marked by significant accumulation of lipid droplets. This was determined by Oil Red O (ORO) staining and triglyceride accumulation. Swertiamarin (25μg/ml) decreased triglyceride content by 2 folds and effectively reduced LDH release (50%) activity by protecting membrane integrity thus, preventing apoptosis evidenced by reduced cleavage of Caspase 3 and PARP1. We observed that swertiamarin significantly increased the expressions of major insulin signaling proteins like Insulin receptor (IR), PI(3)K, pAkt with concomitant reduction in p307 IRS-1. AMPK was activated by swertiamarin action, thus restoring insulin sensitivity in hepatocytes. In addition, qPCR results confirmed OA up-regulated Sterol Regulatory Element Binding Protein (SREBP)-1c and fatty acid synthase (FAS), resulting in increased fatty acid synthesis. Swertiamarin effectively modulated PPAR-α, a major potential regulator of carbohydrate metabolism which, in turn, decreased the levels of the gluconeogenic enzyme PEPCK, further restricting hepatic glucose production and fatty acid synthesis. Cumulatively, swertiamarin targets potential metabolic regulators AMPK and PPAR-α, through which it regulates hepatic glycemic burden, fat accumulation, insulin resistance and ROS in hepatic steatosis which emphasizes clinical significance of swertiamarin in regulating metabolism and as a suitable candidate for treating NAFLD.

  19. Comparative study of cadmium and lead accumulations in Cambarus bartoni (Fab. ) (Decapoda, Crustacea) from an acidic and a neutral lake

    SciTech Connect

    Keenan, S.; Alikhan, M.A. )

    1991-07-01

    The purpose of the study reported in this paper was to compare concentrations of lead and cadmium in the sediment and water, as well as in the crayfish, Cambarus Bartoni (Fab.) (Decapoda - Crustacea) trapped from an acidic and a neutral lake in the Sudbury district of Northeastern Ontario. Hepatopancreatic, alimentary canal, tail muscles and exoskeletal concentrations in the crayfish are also examined to determine specific tissue sites for these accumulations.

  20. Massive accumulation of gallic acid and unique occurrence of myricetin, quercetin, and kaempferol in preparing old oolong tea.

    PubMed

    Lee, Viola S Y; Dou, Jianpeng; Chen, Ronald J Y; Lin, Ruey-Song; Lee, Maw-Rong; Tzen, Jason T C

    2008-09-10

    Old oolong tea, tasting superior and empirically considered beneficial for human health, is prepared by long-term storage accompanied with periodic drying for refinement. Analyzing infusions of three old and one newly prepared oolong teas showed that significant lower (-)-epigallocatechin gallate (EGCG) but higher gallic acid contents were detected in the old teas compared to the new one. The possibility of releasing gallic acid from EGCG in old tea preparation was supported by an in vitro observation of gallic acid degraded from EGCG under heating conditions mimicking the drying process. Moreover, three minor flavonols, myricetin, quercetin, and kaempferol, that were undetectable in the new tea occurred in all of the three old teas. Converting the new oolong tea into an old one by periodic drying revealed the same characteristic observation, i.e., massive accumulation of gallic acid presumably released from EGCG and unique occurrence of flavonols putatively decomposed from flavonol glycosides.

  1. Cd and Ni transport and accumulation in the halophyte Sesuvium portulacastrum: implication of organic acids in these processes

    PubMed Central

    Mnasri, Mejda; Ghabriche, Rim; Fourati, Emna; Zaier, Hanen; Sabally, Kebba; Barrington, Suzelle; Lutts, Stanley; Abdelly, Chedly; Ghnaya, Tahar

    2015-01-01

    The implication of organic acids in Cd and Ni translocation was studied in the halophyte species Sesuvium portulacastrum. Citric, fumaric, malic, and ascorbic acids were separated and quantified by HPLC technique in shoots, roots and xylem saps of plants grown on nutrient solutions added with 50 μM Cd, 100 μM Ni and the combination of 50 μM Cd + 100 μM Ni. Results showed that Cd had no significant impact on biomass production while Ni and the combination of both metals drastically affected plant development. Cadmium and Ni concentrations in tissues and xylem sap were higher in plants subjected to individual metal application than those subjected to the combined effect of Cd and Ni suggesting a possible competition between these metals for absorption. Both metals applied separately or in combination induced an increase in citrate concentration in shoots and xylem sap but a decrease of this concentration in the roots. However, a minor relationship was observed between metal application and fumaric, malic, and ascorbic acids. Both observations suggest the implication of citric acid in Cd, Ni translocation and shoot accumulation in S. portulacastrum. The relatively high accumulation of citric acid in xylem sap and shoot of S. portulacastrum could be involved in metal chelation and thus contributes to heavy metal tolerance in this species. PMID:25821455

  2. Correlated accumulation of anthocyanins and rosmarinic acid in mechanically stressed red cell suspensions of basil (Ocimum basilicum).

    PubMed

    Strazzer, Pamela; Guzzo, Flavia; Levi, Marisa

    2011-02-15

    A red basil cell line (T2b) rich in rosmarinic acid (RA) was selected for the stable production of anthocyanins (ACs) in the dark. Cell suspension cultures were subjected to mechanical stress through increased agitation (switch from 90 to 150 rpm) to determine the relationship between AC and RA accumulation. Cell extracts were analyzed by HPLC and LC-MS, and the resulting data were processed with multivariate statistical analysis. MS and MS/MS spectra facilitated the putative annotation of several complex cyanidin-based ACs, which were esterified with coumaric acid and, in some cases, also with malonic acid. It was also possible to identify various RA-related molecules, some caffeic and coumaric acid derivatives and some flavanones. Mechanical stress increased the total AC and RA contents, but reduced biomass accumulation. Many metabolites were induced by mechanical stress, including RA and some of its derivatives, most ACs, hydroxycinnamic acids and flavonoids, whereas the abundance of some RA dimers was reduced. Although AC and RA share a common early biosynthetic pathway (from phenylalanine to 4-coumaroyl-CoA) and could have similar or overlapping functions providing antioxidant activity against stress-generated reactive oxygen species, there appeared to be no competition between their individual pathways.

  3. Accumulation of amino acid substitutions promotes irreversible structural changes in the hemagglutinin of human influenza AH3 virus during evolution.

    PubMed

    Nakajima, Katsuhisa; Nobusawa, Eri; Nagy, Alexander; Nakajima, Setsuko

    2005-05-01

    In order to clarify the effect of an accumulation of amino acid substitutions on the hemadsorption character of the influenza AH3 virus hemagglutinin (HA) protein, we introduced single-point amino acid changes into the HA1 domain of the HA proteins of influenza viruses isolated in 1968 (A/Aichi/2/68) and 1997 (A/Sydney/5/97) by using PCR-based random mutation or site-directed mutagenesis. These substitutions were classified as positive or negative according to their effects on the hemadsorption activity. The rate of positive substitutions was about 50% for both strains. Of 44 amino acid changes that were identical in the two strains with regard to both the substituted amino acids and their positions in the HA1 domain, 22% of the changes that were positive in A/Aichi/2/68 were negative in A/Sydney/5/97 and 27% of the changes that were negative in A/Aichi/2/68 were positive in A/Sydney/5/97. A similar discordance rate was also seen for the antigenic sites. These results suggest that the accumulation of amino acid substitutions in the HA protein during evolution promoted irreversible structural changes and therefore that antigenic changes in the H3HA protein may not be limited.

  4. Neurons accumulating [3H]gamma-aminobutyric acid (GABA) in supragranular layers of cat primary auditory cortex (AI)

    PubMed

    Winer, J A

    1986-11-01

    The classes of neurons accumulating exogenously injected, tritiated gamma-aminobutyric acid [( 3H]GABA) were studied in the supragranular layers in the primary auditory field of the adult cat. The size, laminar locus, and somatodendritic profiles of labeled neurons were studied light microscopically in frozen- or Vibratome-sectioned, 30 micron thick material, and in semithin, 1-2 micron thick, plastic-embedded high-resolution autoradiographic preparations. The chief goals of the study were to determine which types of cells could be identified as accumulating [3H]GABA in layers I, II and III, and to establish possible relationships between these cells and neurons described in Golgi studies of these layers, and the neurons found, in parallel investigations of the connections of the primary auditory field, to participate as ipsilateral corticocortical and commissural cells of origin. The principal findings are: that neurons in every layer in the primary auditory field take up tritiated gamma-aminobutyric acid; that their Nissl-counterstained somata have a smaller average area, and a smaller range of areas, than do the unlabeled cells; that more than one type of labeled neuron-as defined by somatic size and shape, height:width ratios, and nuclear membrane morphology-could be identified in each layer; that none of the labeled neurons had a soma with a pyramidal configuration; that the labeled cells are comparable in size, shape, and laminar distribution to some populations of non-pyramidal ipsilateral corticocortical cells of origin in layers II and III, and perhaps to certain classes of commissurally projecting, layer III non-pyramidal neurons; and finally, that only a rather small proportion-perhaps 10% or less, except in layer I-of the supragranular cells appear to accumulate labeled material. With regard to the identity of particular classes of neurons accumulating silver grains above background in the individual layers, in layer I, 2 of the 4 types of neurons

  5. Identification and expression of a stearoyl-ACP desaturase gene responsible for oleic acid accumulation in Xanthoceras sorbifolia seeds.

    PubMed

    Zhao, Na; Zhang, Yuan; Li, Qiuqi; Li, Rufang; Xia, Xinli; Qin, Xiaowei; Guo, Huihong

    2015-02-01

    Xanthoceras sorbifolia Bunge is an oilseed tree that grows well on barren lands in dry climate. Its seeds contain a large amount of oil rich in oleic acid (18:1(Δ9)) and linoleic acid (18:2(Δ9, 12)). However, the molecular regulation of oil biosynthesis in X. sorbifolia seeds is poorly understood. Stearoyl-ACP desaturase (SAD, EC 1.14.99.6) is a plastid-localized soluble desaturase that catalyzes the conversion of stearic acid (18:0) to oleic acid, which plays a key role in determining the ratio of saturated to unsaturated fatty acids. In this study, a full-length cDNA of XsSAD was isolated from developing X. sorbifolia embryos. The XsSAD open reading frame had 1194-bp, encoding a polypeptide of 397 amino acids. XsSAD expression in Escherichia coli cells resulted in increased 18:1(Δ9) level, confirming the biological activity of the enzyme encoded by XsSAD. XsSAD expression in Arabidopsis ssi2 mutants partially restored the morphological phenotype and effectively increased the 18:1(Δ9) level. The levels of other unsaturated fatty acids synthesized with 18:1(Δ9) as the substrate also increased to some degree. XsSAD in X. sorbifolia had a much higher expression in embryos than in leaves and petals. XsSAD expression also correlated well with the oleic acid, unsaturated fatty acid, and total fatty acid levels in developing embryos. These data suggested that XsSAD determined the synthesis of oleic acid and contributed to the accumulation of unsaturated fatty acid and total oil in X. sorbifolia seeds. A preliminary tobacco rattle virus-based virus-induced gene silencing system established in X. sorbifolia can also be helpful for further analyzing the functions of XsSAD and other oil synthesis-related genes in woody plants.

  6. Wound and insect-induced jasmonate accumulation in carnivorous Drosera capensis: two sides of the same coin.

    PubMed

    Mithöfer, A; Reichelt, M; Nakamura, Y

    2014-09-01

    Carnivorous sundew plants catch and digest insect prey for their own nutrition. The sundew species Drosera capensis shows a pronounced leaf bending reaction upon prey capture in order to form an 'outer stomach'. This formation is triggered by jasmonates, phytohormones typically involved in defence reactions against herbivory and wounding. Whether jasmonates still have this function in D. capensis in addition to mediating the leaf bending reaction was investigated here. Wounded, insect prey-fed and insect-derived oral secretion-treated leaves of D. capensis were analysed for jasmonates (jasmonic acid, JA; jasmonic acid-isoleucine conjugate, JA-Ile) using LC-MS/MS. Prey-induced jasmonate accumulation in D. capensis leaves was persistent, and showed high levels of JA and JA-Ile (575 and 55.7 pmol · g · FW(-1) , respectively), whereas wounding induced a transient increase of JA (maximum 500 pmol · g · FW(-1) ) and only low (3.1 pmol · g · FW(-1) ) accumulation of JA-Ile. Herbivory, mimicked with a combined treatment of wounding plus oral secretion (W+OS) obtained from Spodoptera littoralis larvae induced both JA (4000 pmol · g · FW(-1) ) and JA-Ile (25 pmol · g · FW(-1) ) accumulation, with kinetics similar to prey treatment. Only prey and W+OS, but not wounding alone or OS, induced leaf bending. The results indicate that both mechanical and chemical stimuli trigger JA and JA-Ile synthesis. Differences in kinetics and induced jasmonate levels suggest different sensing and signalling events upon injury and insect-dependent challenge. Thus, in Drosera, jasmonates are still part of the response to wounding. Jasmonates are also employed in insect-induced reactions, including responses to herbivory and carnivory.

  7. Fungal biotransformation of chlorogenic and caffeic acids by Fusarium graminearum: New insights in the contribution of phenolic acids to resistance to deoxynivalenol accumulation in cereals.

    PubMed

    Gauthier, Léa; Bonnin-Verdal, Marie-Noelle; Marchegay, Gisèle; Pinson-Gadais, Laetitia; Ducos, Christine; Richard-Forget, Florence; Atanasova-Penichon, Vessela

    2016-03-16

    Fusarium Head Blight and Gibberella Ear Rot, mainly caused by the fungi Fusarium graminearum and Fusarium culmorum, are two of the most devastating diseases of small-grain cereals and maize. In addition to yield loss, these diseases frequently result in contamination of kernels with toxic type B trichothecenes. The potential involvement of chlorogenic acid in cereal resistance to Fusarium Head Blight and Gibberella Ear Rot and to trichothecene accumulation was the focus of this study. The effects of chlorogenic acid and one of its hydrolyzed products, caffeic acid, on fungal growth and type B trichothecenes biosynthesis were studied using concentrations close to physiological amounts quantified in kernels and a set of F. graminearum and F. culmorum strains. Both chlorogenic and caffeic acids negatively impact fungal growth and mycotoxin production, with caffeic acid being significantly more toxic. Inhibitory efficiencies of both phenolic acids were strain-dependent. To further investigate the antifungal and anti "mycotoxin" effect of chlorogenic and caffeic acids, the metabolic fate of these two phenolic acids was characterized in supplemented F. graminearum broths. For the first time, our results demonstrated the ability of F. graminearum to degrade chlorogenic acid into caffeic, hydroxychlorogenic and protocatechuic acids and caffeic acid into protocatechuic and hydroxycaffeic acids. Some of these metabolic products can contribute to the inhibitory efficiency of chlorogenic acid that, therefore, can be compared as a "pro-drug". As a whole, our data corroborate the contribution of chlorogenic acid to the chemical defense that cereals employ to counteract F. graminearum and its production of mycotoxins.

  8. Effect of different postharvest temperatures on the accumulation of sugars, organic acids, and amino acids in the juice sacs of Satsuma mandarin (Citrus unshiu Marc.) fruit.

    PubMed

    Matsumoto, Hikaru; Ikoma, Yoshinori

    2012-10-03

    To elucidate the effect of different postharvest temperatures on the accumulation of sugars, organic acids, and amino acids and to determine the best temperature to minimize their postharvest change, their content after harvest was investigated at 5, 10, 20, and 30 °C for 14 days in the juice sacs of Satsuma mandarin (Citrus unshiu Marc. cv. Aoshima-unshiu) fruit. In all sugars, the changes were negligible at all temperatures. Organic acids decreased slightly at all temperatures, with the exception of malic acid at 30 °C, which increased slightly. Two amino acids, ornithine and glutamine, increased at 5 °C, but they did not increase at other temperatures. In 11 amino acids (phenylalanine, tryptophan, tyrosine, isoleucine, leucine, valine, threonine, lysine, methionine, histidine, and γ-amino butyric acid), the content was higher at 20 and 30 °C than at other temperatures. Thus, the content of amino acids was more variable than that of sugars and organic acids in response to temperatures. Moreover, amino acids responded to temperature differently: two amino acids were cold responsive, and 11 were heat-responsive. The best temperature to minimize the postharvest changes in amino acid profiles in the juice sacs of Aoshima-unshiu was 10 °C. The responsiveness to temperatures in two cold-responsive (ornithine and glutamine) and five heat-responsive (phenylalanine, tryptophan, valine, lysine, and histidine) amino acids was conserved among three different Satsuma mandarin cultivars, Aoshima-unshiu (late-maturing cultivar), Silverhill (midmaturing cultivar), and Miyagawa-wase (early-maturing cultivar). The metabolic responsiveness to temperature stress was discussed on the basis of the changes in the amino acid profile.

  9. Relationships between Photosynthetically Active Radiation, Nocturnal Acid Accumulation, and CO2 Uptake for a Crassulacean Acid Metabolism Plant, Opuntia ficus-indica1

    PubMed Central

    Nobel, Park S.; Hartsock, Terry L.

    1983-01-01

    The influences of photosynthetically active radiation (PAR) and water status on nocturnal Crassulacean acid metabolism (CAM) were quantitatively examined for a widely cultivated cactus, Opuntia ficus-indica (L.) Miller. When the total daily PAR was maintained at 10 moles photons per square meter per day but the instantaneous PAR level varied, the rate of nocturnal H+ accumulation (tissue acidification) became 90% saturated near 700 micromoles per square meter per second, a PAR level typical for similar light saturation of C3 photosynthesis. The total nocturnal H+ accumulation and CO2 uptake reached 90% of maximum for a total daily PAR of about 22 moles per square meter per day. Light compensation occurred near 0 moles per square meter per day for nocturnal H+ accumulation and 4 moles per square meter per day for CO2 uptake. Above a total daily PAR of 36 moles per square meter per day or for an instantaneous PAR of 1150 micromoles per square meter per second for more than 6 hours, the nocturnal H+ accumulation actually decreased. This inhibition, which occurred at PAR levels just above those occurring in the field, was accompanied by a substantial decrease in chlorophyll content over a 1-week period. A minimum ratio of H+ accumulated to CO2 taken up of 2.5 averaged over the night occurred for a total daily PAR of 31 moles per square meter per day under wet conditions. About 2 to 6 hours into the night under such conditions, a minimum H+-to-CO2 ratio of 2.0 was observed. Under progressively drier conditions, both nocturnal H+ accumulation and CO2 uptake decreased, but the H+-to-CO2 ratio increased. A ratio of two H+ per CO2 is consistent with the H+ production accompanying the conversion of starch to malic acid, and it apparently occurs for O. ficus-indica when CAM CO2 uptake is strongly favored over respiratory activity. PMID:16662802

  10. Acidification, heavy metal mobility and nutrient accumulation in the soil-plant system of a revegetated acid mine wasteland.

    PubMed

    Yang, Sheng-Xiang; Liao, Bin; Li, Jin-tian; Guo, Tao; Shu, Wen-Sheng

    2010-08-01

    A revegetation program was established at an extreme acidic and metal-toxic pyrite/copper mine wasteland in Guangdong Province, PR China using a combination of four native grass species and one non-native woody species. It was continued and monitored for 2 y. The emphasis was on acidification, metal mobility and nutrient accumulation in the soil-plant system. Our results showed the following: (i) the acid-forming potential of the mine soils decreased steadily with time, which might be due to plant root-induced changes inhibiting the oxidization of sulphide minerals; (ii) heavy metal extractability (diethylene-triamine-pentaacetic acid-extractable Pb and Zn) in the soils increased with time despite an increase in soil pH, which might be attributed to soil disturbance and plant rhizospheric processes, as well as a consequence of the enhanced metal accumulation in plants over time; and (iii) the vegetation cover increased rapidly with time, and plant development accelerated the accumulation of major nutrients (organic matter, total and ammonium-N, and available P and K). The 2-y field experiment demonstrates that direct seeding/planting of native plant species in combination with lime and manure amelioration is a practical approach to the initial establishment of a self-sustaining vegetation cover on this metalliferous and sulphide-bearing mine wasteland. However, heavy metal accumulation in the soil-plant system should be of great concern, and long-term monitoring of ecological risk must be an integral part of such a restoration scheme.

  11. The activity of HYDROPEROXIDE LYASE 1 regulates accumulation of galactolipids containing 12-oxo-phytodienoic acid in Arabidopsis

    PubMed Central

    Nilsson, Anders K.; Fahlberg, Per; Johansson, Oskar N.; Hamberg, Mats; Andersson, Mats X.; Ellerström, Mats

    2016-01-01

    Arabidopsis produces galactolipids containing esters of 12-oxo-phytodienoic acid (OPDA) and dinor-12-oxo-phytodienoic acid (dnOPDA). These lipids are referred to as arabidopsides and accumulate in response to abiotic and biotic stress. We explored the natural genetic variation found in 14 different Arabidopsis accessions to identify genes involved in the formation of arabidopsides. The accession C24 was identified as a poor accumulator of arabidopsides whereas the commonly used accession Col-0 was found to accumulate comparably large amounts of arabidopsides in response to tissue damage. A quantitative trait loci analysis of an F2 population created from a cross between C24 and Col-0 located a region on chromosome four strongly linked to the capacity to form arabidopsides. Expression analysis of HYDROPEROXIDE LYASE 1 (HPL1) showed large differences in transcript abundance between accessions. Transformation of Col-0 plants with the C24 HPL1 allele under transcriptional regulation of the 35S promoter revealed a strong negative correlation between HPL1 expression and arabidopside accumulation after tissue damage, thereby strengthening the view that HPL1 competes with ALLENE OXIDE SYNTHASE (AOS) for lipid-bound hydroperoxide fatty acids. We further show that the last step in the synthesis of galactolipid-bound OPDA and dnOPDA from unstable allene oxides is exclusively enzyme-catalyzed and not the result of spontaneous cyclization. Thus, the results presented here together with previous studies suggest that all steps in arabidopside biosynthesis are enzyme-dependent and apparently all reactions can take place with substrates being esterified to galactolipids. PMID:27422994

  12. Fatty Acid Transport Protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

    PubMed Central

    Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C.

    2015-01-01

    The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC50 8–11μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC50 58μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of 13C-oleate demonstrating its potential as a therapeutic agent. PMID:26284975

  13. Host-Pathogen interactions. 25. Endopolygalacturonic acid lyase from Erwinia carotovora elicits phytoalexin accumulation by releasing plant cell wall fragments

    SciTech Connect

    Davis, K.R.; Lyon, G.D.; Darvill, A.G.; Albersheim, P.

    1984-01-01

    Heat-labile elicitors of phytoalexin accumulation in soybeans (Glycine max L. Merr. cv Wayne) were detected in culture filtrates of Erwinia carotovora grown on a defined medium containing citrus pectin as the sole carbon source. The heat-labile elicitors were highly purified by cation-exchange chromatography on a CM-Sephadex (C-50) column, followed by agarose-affinity chromatography on a Bio-Gel A-0.5m gel filtration column. The heat-labile elicitor activity co-purified with two ..cap alpha..-1,4-endopolygalacturonic acid lyases (EC 4 x 2 x 2 x 2). Endopolygalacturonic acid lyase activity appeared to be necessary for elicitor activity because heat-inactivated enzyme preparations did not elicit phytoalexins. The purified endopolygalacturonic acid lyases elicited pterocarpan phytoalexins at microbial-inhibitory concentrations in the soybean-cotyledon bioassay when applied at a concentration of 55 nanograms per milliliter (1 x 10/sup -9/ molar). One of these lyases released heat-stable elicitors from soybean cell walls, citrus pectin, and sodium polypectate. The heat-stable elicitor-active material solubilized from soybean cell walls by the lyase was composed of at least 90% (w/v) uronosyl residues. These results demonstrate that endopolygalacturonic acid lyase elicits phytoalexin accumulation by releasing fragments from pectic polysaccharides in plant cell walls.

  14. Long-chain 3-hydroxy fatty acids accumulating in LCHAD and MTP deficiencies induce oxidative stress in rat brain.

    PubMed

    Tonin, Anelise M; Grings, Mateus; Busanello, Estela N B; Moura, Alana P; Ferreira, Gustavo C; Viegas, Carolina M; Fernandes, Carolina G; Schuck, Patrícia F; Wajner, Moacir

    2010-07-01

    Accumulation of long-chain 3-hydroxy fatty acids is the biochemical hallmark of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (MTP) deficiencies. These disorders are clinically characterized by neurological symptoms, such as convulsions and lethargy, as well as by cardiomyopathy and muscle weakness. In the present work we investigated the in vitro effect of 3-hydroxydodecanoic (3HDA), 3-hydroxytetradecanoic (3HTA) and 3-hydroxypalmitic (3HPA) acids, which accumulate in these disorders, on important oxidative stress parameters in cerebral cortex of young rats in the hope to clarify the mechanisms leading to the brain damage found in patients affected by these disorders. It was first verified that these compounds significantly induced lipid peroxidation, as determined by increased thiobarbituric acid-reactive substances levels. In addition, carbonyl formation was significantly increased and sulfhydryl content decreased by 3HTA and 3HPA, which indicates that these fatty acids elicit protein oxidative damage. 3HTA and 3HPA also diminished the reduced glutathione (GSH) levels, without affecting nitrate and nitrite production. Finally, we observed that the addition of the antioxidants and free radical scavengers trolox and deferoxamine (DFO) was able to partially prevent lipid oxidative damage, whereas DFO fully prevented the reduction on GSH levels induced by 3HTA. Our present data showing that 3HDA, 3HTA and 3HPA elicit oxidative stress in rat brain indicate that oxidative damage may represent an important pathomechanism involved in the neurologic symptoms manifested by patients affected by LCHAD and MTP deficiencies.

  15. Light enhanced the accumulation of total fatty acids (TFA) and docosahexaenoic acid (DHA) in a newly isolated heterotrophic microalga Crypthecodinium sp. SUN.

    PubMed

    Sun, Dongzhe; Zhang, Zhao; Mao, Xuemei; Wu, Tao; Jiang, Yue; Liu, Jin; Chen, Feng

    2017-03-01

    In the present study, light illumination was found to be efficient in elevating the total fatty acid content in a newly isolated heterotrophic microalga, Crypthecodinium sp. SUN. Under light illumination, the highest total fatty acid and DHA contents were achieved at 96h as 24.9% of dry weight and 82.8mgg(-1) dry weight, respectively, which were equivalent to 1.46-fold and 1.68-fold of those under the dark conditions. The elevation of total fatty acid content was mainly contributed by an increase of neutral lipids at the expense of starches. Moreover, light was found to alter the cell metabolism and led to a higher specific growth rate, higher glucose consumption rate and lower non-motile cell percentage. This is the first report that light can promote the total fatty acids accumulation in Crypthecodinium without growth inhibition.

  16. Antagonistic effects of abscisic acid and jasmonates on salt stress-inducible transcripts in rice roots.

    PubMed Central

    Moons, A; Prinsen, E; Bauw, G; Van Montagu, M

    1997-01-01

    Abscisic acid (ABA) and jasmonates have been implicated in responses to water deficit and wounding. We compared the molecular and physiological effects of jasmonic acid (JA) (< or = 10 microM), ABA, and salt stress in roots of rice. JA markedly induced a cationic peroxidase, two novel 32- and 28-kD proteins, acidic PR-1 and PR-10 pathogenesis-related proteins, and the salt stress-responsive SalT protein in roots. Most JA-responsive proteins (JIPs) from roots also accumulated when plants were subjected to salt stress. None of the JIPs accumulated when plants were treated with ABA. JA did not induce an ABA-responsive group 3 late-embryogenesis abundant (LEA) protein. Salt stress and ABA but not JA induced oslea3 transcript accumulation. By contrast, JA, ABA, and salt stress induced transcript accumulation of salT and osdrr, which encodes a rice PR-10 protein. However, ABA also negatively affected salT transcript accumulation, whereas JA negatively affected ABA-induced oslea3 transcript levels. Endogenous root ABA and methyl jasmonate levels showed a differential increase with the dose and the duration of salt stress. The results indicate that ABA and jasmonates antagonistically regulated the expression of salt stress-inducible proteins associated with water deficit or defense responses. PMID:9437865

  17. Manganese accumulation in membrane fractions of primary astrocytes is associated with decreased γ-aminobutyric acid (GABA) uptake, and is exacerbated by oleic acid and palmitate.

    PubMed

    Fordahl, Steve C; Erikson, Keith M

    2014-05-01

    Manganese (Mn) exposure interferes with GABA uptake; however, the effects of Mn on GABA transport proteins (GATs) have not been identified. We sought to characterize how Mn impairs GAT function in primary rat astrocytes. Astrocytes exposed to Mn (500 μM) had significantly reduced (3)H-GABA uptake despite no change in membrane or cytosolic GAT3 protein levels. Co-treatment with 100 μM oleic or palmitic acids (both known to be elevated in Mn neurotoxicity), exacerbated the Mn-induced decline in (3)H-GABA uptake. Mn accumulation in the membrane fraction of astrocytes was enhanced with fatty acid administration, and was negatively correlated with (3)H-GABA uptake. Furthermore, control cells exposed to Mn only during the experimental uptake had significantly reduced (3)H-GABA uptake, and the addition of GABA (50 μM) blunted cytosolic Mn accumulation. These data indicate that reduced GAT function in astrocytes is influenced by Mn and fatty acids accumulating at or interacting with the plasma membrane.

  18. Accumulation of boron in malignant and normal cells incubated in vitro with boronophenylalanine, mercaptoborane or boric acid.

    PubMed

    Capala, J; Makar, M S; Coderre, J A

    1996-11-01

    The short (< 10 microns) ranges of alpha and 7Li particles produced during boron neutron capture therapy (BNCT) make the partitioning of the boronated drug within and without the cell of critical importance. The evaluation of the potential usefulness of a boron-containing substance for BNCT requires information about its intracellular accumulation. In the present report, an in vitro method is described for direct measurement of intracellular boron based on rapid centrifugation of cells through a layer of mineral oil and silicon oil to strip away extracellular growth medium. The intracellular concentrations of boronophenylalanine (BPA), mercaptoborane (BSH) and horic acid in malignant cells and in normal cells have been compared. The accumulation ratio is defined as the ratio of the intracellular to the extracellular boron concentration. Boric acid showed an accumulation ratio of 1 while the ratios for BSH and BPA were dependent on cell type and tended to be greater for BPA than for BSH in malignant but not in normal cells.

  19. Abscisic acid promotes accumulation of toxin ODAP in relation to free spermine level in grass pea seedlings (Lathyrus sativus L.).

    PubMed

    Xiong, You-Cai; Xing, Geng-Mei; Li, Feng-Min; Wang, Shao-Ming; Fan, Xian-Wei; Li, Zhi-Xiao; Wang, Ya-Fu

    2006-01-01

    Interrelationship among abscisic acid (ABA) content, accumulation of free polyamines and biosynthesis of beta-N-oxalyl-l-alpha,beta-diaminopropionic acid (ODAP) was studied in grass pea (Lathyrus sativus L.) seedlings under drought stress induced by 10% polyethylene glycol (PEG6000). Increase of ABA content occurred prior to that of ODAP and polyamine contents, and was found significantly positive correlation between ABA content and ODAP content. Addition of exogenous ABA increased ODAP content in leaves. On the other hand, pretreatment with alpha-difluoromethylarginine (DFMA), a polyamine biosynthesis inhibitor, significantly suppressed the accumulation of free putrescine (Put), free spermidine (Spd) and free spermine (Spm), which in turn inhibited biosynthesis of ODAP in well-watered leaves. Meanwhile, addition of exogenous Put alleviated DFMA-induced inhibition on the biosynthesis of Put and Spd, but did not affect the biosynthesis of Spm and ODAP in well-watered leaves. Same result was also achieved in drought-stressed leaves. Increasing accumulation of ODAP was significantly correlated with increasing Spm content (R=0.7957**) but not with that of Spd and Put. Therefore, it can be argued that ABA stimulated the biosynthesis of ODAP simultaneously with increasing the level of free Spm under drought stress condition.

  20. γ-Aminobutyric acid addition alleviates ammonium toxicity by limiting ammonium accumulation in rice (Oryza sativa) seedlings.

    PubMed

    Ma, Xiaoling; Zhu, Changhua; Yang, Na; Gan, Lijun; Xia, Kai

    2016-12-01

    Excessive use of nitrogen (N) fertilizer has increased ammonium (NH4(+) ) accumulation in many paddy soils to levels that reduce rice vegetative biomass and yield. Based on studies of NH4(+) toxicity in rice (Oryza sativa, Nanjing 44) seedlings cultured in agar medium, we found that NH4(+) concentrations above 0.75 mM inhibited the growth of rice and caused NH4(+) accumulation in both shoots and roots. Use of excessive NH4(+) also induced rhizosphere acidification and inhibited the absorption of K, Ca, Mg, Fe and Zn in rice seedlings. Under excessive NH4(+) conditions, exogenous γ-aminobutyric acid (GABA) treatment limited NH4(+) accumulation in rice seedlings, reduced NH4(+) toxicity symptoms and promoted plant growth. GABA addition also reduced rhizosphere acidification and alleviated the inhibition of Ca, Mg, Fe and Zn absorption caused by excessive NH4(+) . Furthermore, we found that the activity of glutamine synthetase/NADH-glutamate synthase (GS; EC 6.3.1.2/NADH-GOGAT; EC1.4.1.14) in root increased gradually as the NH4(+) concentration increased. However, when the concentration of NH4(+) is more than 3 mM, GABA treatment inhibited NH4(+) -induced increases in GS/NADH-GOGAT activity. The inhibition of ammonium assimilation may restore the elongation of seminal rice roots repressed by high NH4(+) . These results suggest that mitigation of ammonium accumulation and assimilation is essential for GABA-dependent alleviation of ammonium toxicity in rice seedlings.

  1. Exogenous malic acid alleviates cadmium toxicity in Miscanthus sacchariflorus through enhancing photosynthetic capacity and restraining ROS accumulation.

    PubMed

    Guo, Haipeng; Chen, Houming; Hong, Chuntao; Jiang, Dean; Zheng, Bingsong

    2017-03-18

    Malic acid (MA) plays an important role in the regulation of plant growth, stomatal aperture, nutrition elements homeostasis and toxic metals tolerance. However, little is known about the effects of exogenous MA on physiological and biochemical responses to toxic metals in plants. To measure the alleviation roles of exogenous MA against cadmium (Cd), we determined the effects of MA on plant growth, net photosynthetic rate (Pn), reactive oxygen species (ROS) accumulation and the activities of anti-oxidant enzymes in the leaves of Miscanthus sacchariflorus (M. sacchariflorus) under Cd stress. The Cd exposure alone significantly inhibited plant growth and Pn, but increased the accumulation of ROS even though the anti-oxidant enzymes were markedly activated in the leaves of M. sacchariflorus. Treatment with MA significantly enhanced plant growth and decreased Cd accumulation accompanied by increasing Pn under Cd stress as compared to Cd stress alone, especially when treatment with high concentration of MA (200μM) was used. In addition, Cd and MA indicated synergistic effects by further increasing the activities and genes expression of partial anti-oxidant enzymes, thus resulting in higher glutathione accumulation and reduction of ROS production. The results showed that application of MA alleviated Cd-induced phytotoxicity and oxidant damage through the regulation of both enzymatic and non-enzymatic anti-oxidants under Cd stress in M. sacchariflorus.

  2. Formation and accumulation of protoporphyrin IX in tumor and nontumor cell lines induced by 5-aminolevulinic acid

    NASA Astrophysics Data System (ADS)

    Fernandez, Sandra R.; Milanetto, Marilia; Bagnato, Vanderlei S.; Imasato, Hidetake; Perussi, Janice R.

    2005-04-01

    The endogenous photosensitizer 5-aminolevulinic acid (ALA) is a haem precursor and induces the synthesis of protoporphyrin IX (PpIX) in mitochondria-containing cells. Due to the slow conversion of porphyrins to haem, high levels of PPIX are found in the tissues, sufficient to produce a photodynamic effect following exposure to light. Since PpIX accumulates effectively in tumor cells, the use of ALA leads to a better photoselectivity than Photofrin. However, this selectivity has not been sufficiently studied. As far as we know there is just one study comparing the amount of accumulated PpIX in non-tumor and tumor cell lines. In this work we attempt to compare not just the production but also the accumulation and cytotoxicity of PpIX in non-tumor (VERO) versus tumor (Hep-2) cells induced by the use of ALA. The results have shown that both non-tumor and tumor cell lines produce the same amount of PpIX but just the tumor cells can accumulate PpIX. So, under illumination, only the tumor cells will be killed.

  3. Early neoplastic and metastatic mammary tumours of transgenic mice detected by 5-aminolevulinic acid-stimulated protoporphyrin IX accumulation

    PubMed Central

    Dorward, A M; Fancher, K S; Duffy, T M; Beamer, W G; Walt, H

    2005-01-01

    A photodynamic technique for human breast cancer detection founded upon the ability of tumour cells to rapidly accumulate the fluorescent product protoporphyrin IX (PpIX) has been applied to transgenic mouse models of mammary tumorigenesis. A major goal of this investigation was to determine whether mouse mammary tumours are reliable models of human disease in terms of PpIX accumulation, for future mechanistic and therapeutic studies. The haeme substrate 5-aminolevulinic acid (5-ALA) (200 mg kg−1) was administered to mouse strains that develop mammary tumours of various histological subtypes upon expression of the transgenic oncogenes HRAS, Polyoma Virus middle T antigen, or Simian Virus 40 large T antigen in the mammary gland. Early neoplastic lesions, primary tumours and metastases showed consistent and rapid PpIX accumulation compared to the normal surrounding tissues, as evidenced by red fluorescence (635 nm) when the tumours were directly illuminated with blue light (380–440 nm). Detection of mouse mammary tumours at the stage of ductal carcinoma in situ by red fluorescence emissions suggests that enhanced PpIX synthesis is a good marker for early tumorigenic processes in the mammary gland. We propose the mouse models provide an ideal experimental system for further investigation of the early diagnostic and therapeutic potential of 5-ALA-stimulated PpIX accumulation in human breast cancer patients. PMID:16251872

  4. Effect of salinity on seed germination, accumulation of proline and free amino acid in Pennisetum glaucum (L.) R. Br.

    PubMed

    Sneha, Sonam; Rishi, Anirudha; Dadhich, Amit; Chandra, Subhash

    2013-09-01

    Salinity is a major threat to agriculture, plants exhibits a variety of responses to salt stress that enable them to tolerate and survive in such conditions. Salinity affects physiological and biochemical processes in plants. A short term salt stress induced physiological and biochemical response were observed in P. glaucum. The experiment was conducted to understand the influence of salinity on seed germination, proline and free amino acid accumulation in P. glaucum. It was observed that as the salt concentration increased the germination percentage decreased as compared to control as well as the root/shoot length also decreased. This suggests that salinity greatly influences the germination as well as the plant growth. The levels ofbiochemical components proline and free amino acid were measured during the salt stressed condition. The 14 days old seedlings were subjected to 4 salt treatments (50, 100, 150 and 200 mM NaCI), free proline and free amino acids was calculated at 0, 12, 24, 48, 72 and 96th hour. Proline and free amino acid content in the salt stressed tissues increased with increase in salt concentration as well as with duration of salt stress. This result suggests that proline and free amino acid acids acts as compatible solutes in P. glaucum to protect the cellular macromolecules, maintain the osmotic balance and also scavenge the free radicals under salt stressed condition.

  5. Salicylic acid and jasmonic acid are essential for systemic resistance against tobacco mosaic virus in Nicotiana benthamiana.

    PubMed

    Zhu, Feng; Xi, De-Hui; Yuan, Shu; Xu, Fei; Zhang, Da-Wei; Lin, Hong-Hui

    2014-06-01

    Systemic resistance is induced by pathogens and confers protection against a broad range of pathogens. Recent studies have indicated that salicylic acid (SA) derivative methyl salicylate (MeSA) serves as a long-distance phloem-mobile systemic resistance signal in tobacco, Arabidopsis, and potato. However, other experiments indicate that jasmonic acid (JA) is a critical mobile signal. Here, we present evidence suggesting both MeSA and methyl jasmonate (MeJA) are essential for systemic resistance against Tobacco mosaic virus (TMV), possibly acting as the initiating signals for systemic resistance. Foliar application of JA followed by SA triggered the strongest systemic resistance against TMV. Furthermore, we use a virus-induced gene-silencing-based genetics approach to investigate the function of JA and SA biosynthesis or signaling genes in systemic response against TMV infection. Silencing of SA or JA biosynthetic and signaling genes in Nicotiana benthamiana plants increased susceptibility to TMV. Genetic experiments also proved the irreplaceable roles of MeSA and MeJA in systemic resistance response. Systemic resistance was compromised when SA methyl transferase or JA carboxyl methyltransferase, which are required for MeSA and MeJA formation, respectively, were silenced. Moreover, high-performance liquid chromatography-mass spectrometry analysis indicated that JA and MeJA accumulated in phloem exudates of leaves at early stages and SA and MeSA accumulated at later stages, after TMV infection. Our data also indicated that JA and MeJA could regulate MeSA and SA production. Taken together, our results demonstrate that (Me)JA and (Me)SA are required for systemic resistance response against TMV.

  6. Perennial peanut (Arachis glabrata Benth.) leaves contain hydroxycinnamoyl-CoA:tartaric acid hydroxycinnamoyl transferase activity and accumulate hydroxycinnamoyl-tartaric acid esters.

    PubMed

    Sullivan, Michael L

    2014-05-01

    Many plants accumulate hydroxycinnamoyl esters to protect against abiotic and biotic stresses. Caffeoyl esters in particular can be substrates for endogenous polyphenol oxidases (PPOs). Recently, we showed that perennial peanut (Arachis glabrata Benth.) leaves contain PPO and identified one PPO substrate, caftaric acid (trans-caffeoyl-tartaric acid). Additional compounds were believed to be cis- and trans-p-coumaroyl tartaric acid and cis- and trans-feruloyl-tartaric acid, but lack of standards prevented definitive identifications. Here we characterize enzymatic activities in peanut leaves to understand how caftaric acid and related hydroxycinnamoyl esters are made in this species. We show that peanut leaves contain a hydroxycinnamoyl-CoA:tartaric acid hydroxycinnamoyl transferase (HTT) activity capable of transferring p-coumaroyl, caffeoyl, and feruloyl moieties from CoA to tartaric acid (specific activities of 11 ± 2.8, 8 ± 1.8, 4 ± 0.8 pkat mg(-1) crude protein, respectively). The HTT activity was used to make cis- and trans-p-coumaroyl- and -feruloyl-tartaric acid in vitro. These products allowed definitive identification of the corresponding cis- and trans-hydroxycinnamoyl esters extracted from leaves. We tentatively identified sinapoyl-tartaric acid as another major phenolic compound in peanut leaves that likely participates in secondary reactions with PPO-generated quinones. These results suggest hydroxycinnamoyl-tartaric acid esters are made by an acyltransferase, possibly a BAHD family member, in perennial peanut. Identification of a gene encoding HTT and further characterization of the enzyme will aid in identifying determinants of donor and acceptor substrate specificity for this important class of biosynthetic enzymes. An HTT gene could also provide a means by genetic engineering for producing caffeoyl- and other hydroxycinnamoyl-tartaric acid esters in forage crops that lack them.

  7. Foliar amino acid accumulation as an indicator of ecosystem stress for first-year sugar maple seedlings

    SciTech Connect

    McLaughlin, J.W.; Reed, D.D.; Jurgensen, M.F.

    1994-01-01

    Accumulation of certain plant foliar amino acids (arginine, glutamine, and proline) can be used as indicators of anthropogenic and natural stressors, such as atmospheric deposition and mineral nutritional imbalances, which result in decreased plant growth. In this study a number of factors were evaluated to assess the use of foliar amino acid accumulation as indicators of sugar maple seedling stress at two sugar maple dominated forests in Michigan. These factors were: (1) first-year sugar maple (Acer saccharum Marshall) seedling growth, (2) N and P nutrition, (3) soluble foliar and root total amino acid concentrations, and (4) concentrations of foliar arginine, glutamine, and proline. The most southern site (Wellston), which was exposed to high atmospheric deposition and had high available soil P and seedling foliar P, had greater seedling growth. Foliar glutamine, arginine, and proline were greater at the most northern site (Alberta), which received lesser amounts of atmospheric deposition, but also had lower levels of available soil phosphorus, seedling foliar phosphorus, less seedling growth, and greater canopy closure. These results suggest that since atmospheric deposition is high in nitrogen, even the low levels of deposition at Alberta may be interacting with ecological variables such as, available soil phosphorus, light, or moisture to result in NIP imbalances and consequently higher arginine and glutamine concentrations in seedling foliage. 37 refs., 4 figs., 3 tabs.

  8. Abscisic Acid Accumulation Maintains Maize Primary Root Elongation at Low Water Potentials by Restricting Ethylene Production1

    PubMed Central

    Spollen, William G.; LeNoble, Mary E.; Samuels, Timmy D.; Bernstein, Nirit; Sharp, Robert E.

    2000-01-01

    Previous work showed that primary root elongation in maize (Zea mays L.) seedlings at low water potentials (ψw) requires the accumulation of abscisic acid (ABA) (R.E. Sharp, Y. Wu, G.S. Voetberg, I.N. Saab, M.E. LeNoble [1994] J Exp Bot 45: 1743–1751). The objective of the present study was to determine whether the inhibition of elongation in ABA-deficient roots is attributable to ethylene. At a ψw of −1.6 MPa, inhibition of root elongation in dark-grown seedlings treated with fluridone to impose ABA deficiency was largely prevented with two inhibitors of ethylene synthesis (aminooxyacetic acid and aminoethoxyvinylglycine) and one inhibitor of ethylene action (silver thiosulfate). The fluridone treatment caused an increase in the rate of ethylene evolution from intact seedlings. This effect was completely prevented with aminooxyacetic acid and also when ABA was supplied at a concentration that restored the ABA content of the root elongation zone and the root elongation rate. Consistent results were obtained when ABA deficiency was imposed using the vp5 mutant. Both fluridone-treated and vp5 roots exhibited additional morphological symptoms of excess ethylene. The results demonstrate that an important role of ABA accumulation in the maintenance of root elongation at low ψw is to restrict ethylene production. PMID:10712561

  9. Evaluation of physicochemical properties, skin permeation and accumulation profiles of salicylic acid amide prodrugs as sunscreen agent.

    PubMed

    Yan, Yi-Dong; Sung, Jun Ho; Lee, Dong Won; Kim, Jung Sun; Jeon, Eun-Mi; Kim, Dae-Duk; Kim, Dong Wuk; Kim, Jong Oh; Piao, Ming Guan; Li, Dong Xun; Yong, Chul Soon; Choi, Han Gon

    2011-10-31

    Various amide prodrugs of salicylic acid were synthesised, and their physicochemical properties including lipophilicity, chemical stability and enzymatic hydrolysis were investigated. In vivo skin permeation and accumulation profiles were also evaluated using a combination of common permeation enhancing techniques such as the use of a supersaturated solution of permeants in an enhancer vehicle, a lipophilic receptor solution, removal of the stratum corneum and delipidisation of skin. Their capacity factor values were proportional to the degree of carbon-carbon saturation in the side chain. All these amides were highly stable in acetonitrile and glycerine. Amide prodrugs were converted to salicylic acid both in hairless mouse liver and skin homogenates. N-dodecyl salicylamide (C12SM) showed the lowest permeation of salicylic acid in skin compared to the other prodrugs, probably due to its low aqueous solubility. It had a high affinity for the stratum corneum and its accumulation was restricted to only the uppermost layer of skin. Thus, this amide prodrug could be a safer topical sunscreen agent with minimum potential for systemic absorption.

  10. The application of medium-chain fatty acids: edible oil with a suppressing effect on body fat accumulation.

    PubMed

    Takeuchi, Hiroyuki; Sekine, Seiji; Kojima, Keiichi; Aoyama, Toshiaki

    2008-01-01

    The bulk of fatty acids found in our diets consists of long-chain fatty acids (LCFA), which are molecules containing 12 or more carbon atoms. In contrast, medium-chain fatty acids (MCFA) are composed of 8-10 carbon atoms, and are found in palm kernel oil, among other types of foods. MCFA have attracted attention as being part of a healthy diet, because they are absorbed directly into the portal vein, transported rapidly to the liver for beta-oxidation, and thus increase diet-induced thermogenesis. In contrast, long-chain triacylglycerols are absorbed via the intestinal lymphatic ducts and transported by chylomicrons through the thoracic duct into the systemic circulation. Because medium-chain triacylglycerols (MCT) containing solely MCFA have a few disadvantages when used for deep frying, we have developed a new kind of triacylglycerol product: medium- and long-chain triacylglycerol (MLCT). MLCT is produced by lipase-catalyzed enzymatic transesterification. Long-term clinical trials have demonstrated that MLCT and MCT result in less body fat accumulation in humans. MLCT oil has been approved as FOSHU (Food for Specified Health Use) for use as cooking oil with a suppressing effect on body fat accumulation.

  11. Gallic acid and tannase accumulation during fungal solid state culture of a tannin-rich desert plant (Larrea tridentata Cov.).

    PubMed

    Treviño-Cueto, B; Luis, M; Contreras-Esquivel, J C; Rodríguez, R; Aguilera, A; Aguilar, C N

    2007-02-01

    Larrea tridentata (Sesse & Mocino ex DC.) Coville, also known as Larrea, gobernadora, chaparral, or creosote bush, is a shrubby plant which dominates some areas of the desert southwest in the United States and Northern Mexico and its use has not been exploited and standardized. In this study, gobernadora was studied to evaluate its potential use for support of solid state culture. Influence of two minimal media added with gobernadora powder as the sole carbon source and inducer of tannin-degrading enzymes was evaluated. Cultures were initially 70% moisture, had a pH of 5.5 and were inoculated with Aspergillus niger Aa-20 at 2 x 10(7) spores per gram of media. Analysis of pH, moisture, tannin uptake, gallic acid accumulation and tannase production were evaluated. Results indicated a high content of condensed (39.4%dm) and hydrolysable (22.8%dm) tannins. Invasion capacity of fungal growth was of 0.15 mmh(-1). Tannase production reached values of 1040 Ul(-1) at 43 h of culture. During the first 48 h of culture, the concentration of gallic acid accumulation was 0.33 gl(-1). Gobernadora is a potential source of gallic acid and tannase production by solid state culture; however, further optimization of the process is needed.

  12. Accumulation of Free Ricinoleic Acid in Germinating Castor Bean Endosperm 1

    PubMed Central

    Donaldson, Robert P.

    1977-01-01

    Lipids from the endosperm of germinating castor bean (Ricinus communis var. Hale) were separated by thin layer chromatography and quantitated by gas chromatography. During the later stages of lipid breakdown (4-6 days germination at 30 C), several lipid classes were found in addition to the storage triglycerides, which are triricinoleins for the most part. One was identified as free ricinoleic acid, the proportion of which increased as germination progressed. After 6 days germination, ricinoleic acid comprised more than 30% of the total lipid. The appearance of this fatty acid implies that lipase activity (lipolysis) is not strictly coordinated with β oxidation in this tissue. Images PMID:16659994

  13. Element accumulation patterns of deciduous and evergreen tree seedlings on acid soils: implications for sensitivity to manganese toxicity.

    PubMed

    St Clair, Samuel B; Lynch, Jonathan P

    2005-01-01

    Foliar nutrient imbalances, including the hyperaccumulation of manganese (Mn), are correlated with symptoms of declining health in sensitive tree species growing on acidic forest soils. The objectives of this study were to: (1) compare foliar nutrient accumulation patterns of six deciduous (sugar maple (Acer saccharum Marsh.), red maple (Acer rubrum L.), red oak (Quercus rubra L.), white oak (Quercus alba L.), black cherry (Prunus serotina Ehrh.) and white ash (Fraxinus americana L.)) and three evergreen (eastern hemlock (Tsuga canadensis L.), white pine (Pinus strobus L.) and white spruce (Picea glauca (Moench) Voss.)) tree species growing on acidic forest soils; and (2) examine how leaf phenology and other traits that distinguish evergreen and deciduous tree species influence foliar Mn accumulation rates and sensitivity to excess Mn. For the first objective, leaf samples of seedlings from five acidic, non-glaciated field sites on Pennsylvania's Allegheny Plateau were collected and analyzed for leaf element concentrations. In a second study, we examined growth and photosynthetic responses of seedlings exposed to excess Mn in sand culture. In field samples, Mn in deciduous foliage hyperaccumulated to concentrations more than twice as high as those found in evergreen needles. Among species, sugar maple was the most sensitive to excess Mn based on growth and photosynthetic measurements. Photosynthesis in red maple and red oak was also sensitive to excess Mn, whereas white oak, black cherry, white ash and the three evergreen species were tolerant of excess Mn. Among the nine species, relative rates of photosynthesis were negatively correlated with foliar Mn concentrations, suggesting that photosynthetic sensitivity to Mn is a function of its rate of accumulation in seedling foliage.

  14. Fatty acid transport protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

    SciTech Connect

    Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C.

    2015-09-25

    The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC{sub 50} 8–11 μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC{sub 50} 58 μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of {sup 13}C-oleate demonstrating its potential as a therapeutic agent. - Highlights: • Grassofermata is a small compound inhibitor of FATP2. • Uptake inhibition is specific for long chain fatty acids. • Uptake kinetics shows low specificity for adipocytes compared to other cell types. • Inhibition is by a non-competitive mechanism. • Atypical antipsychotics do not inhibit FA uptake by comparison with Grassofermata.

  15. Acetate accumulation enhances mixed culture fermentation of biomass to lactic acid.

    PubMed

    Khor, Way Cern; Roume, Hugo; Coma, Marta; Vervaeren, Han; Rabaey, Korneel

    2016-10-01

    Lactic acid is a high-in-demand chemical, which can be produced through fermentation of lignocellulosic feedstock. However, fermentation of complex substrate produces a mixture of products at efficiencies too low to justify a production process. We hypothesized that the background acetic acid concentration plays a critical role in lactic acid yield; therefore, its retention via selective extraction of lactic acid or its addition would improve overall lactic acid production and eliminate net production of acetic acid. To test this hypothesis, we added 10 g/L of acetate to fermentation broth to investigate its effect on products composition and concentration and bacterial community evolution using several substrate-inoculum combinations. With rumen fluid inoculum, lactate concentrations increased by 80 ± 12 % (cornstarch, p < 0.05) and 16.7 ± 0.4 % (extruded grass, p < 0.05) while with pure culture inoculum (Lactobacillus delbrueckii and genetically modified (GM) Escherichia coli), a 4 to 23 % increase was observed. Using rumen fluid inoculum, the bacterial community was enriched within 8 days to >69 % lactic acid bacteria (LAB), predominantly Lactobacillaceae. Higher acetate concentration promoted a more diverse LAB population, especially on non-inoculated bottles. In subsequent tests, acetate was added in a semi-continuous percolation system with grass as substrate. These tests confirmed our findings producing lactate at concentrations 26 ± 5 % (p < 0.05) higher than the control reactor over 20 days operation. Overall, our work shows that recirculating acetate has the potential to boost lactic acid production from waste biomass to levels more attractive for application.

  16. Effect of Tween 80 on the growth, lipid accumulation and fatty acid composition of Thraustochytrium aureum ATCC 34304.

    PubMed

    Taoka, Yousuke; Nagano, Naoki; Okita, Yuji; Izumida, Hitoshi; Sugimoto, Shinichi; Hayashi, Masahiro

    2011-04-01

    Thraustochytrium aureum ATCC 34304 was grown in the presence and absence of polyoxyethylene sorbitan monooleate (Tween 80). The aim of this work was to obtain basic knowledge about the effect of Tween 80 on growth, lipid accumulation and fatty acid composition in T. aureum. The addition of Tween 80 to a culture medium significantly enhanced the growth of T. aureum, and the biomass increased with an increase of Tween 80 content. Total lipid content and total fatty acid content were significantly higher in 1.0% Tween 80 in comparison with the control (absence of Tween 80). The fatty acid profile showed that the content of C18:1n-9 (oleic acid) significantly increased as a result of the addition of Tween 80. These results indicated that part of the Tween 80 added to the medium was utilized as a carbon source or that the oleate included in Tween 80 was directly incorporated into T. aureum cells as a fatty acid. Neither the DHA content nor the percentage of DHA did not change in spite of the addition of Tween 80. However, the DHA yield significantly increased because the biomass increased due to the addition of Tween 80.

  17. Accumulation of p-hydroxybenzoic acid in hairy roots of Daucus carota 2: confirming biosynthetic steps through feeding of inhibitors and precursors.

    PubMed

    Sircar, Debabrata; Mitra, Adinpunya

    2009-09-01

    Biosynthesis of hydroxybenzoates even at enzymatic level is poorly understood. In this report, effect of feeding of putative biosynthetic precursors and pathway-specific enzyme inhibitors of early phenylpropanoid pathway on p-hydroxybenzoic acid accumulation in chitosan-elicited hairy roots of Daucus carota was studied. Three selective metabolic inhibitors of plant phenylpropanoid pathway, namely, aminooxyacetic acid (AOAA), piperonylic acid (PIP) and 3,4-methylenedioxycinnamic acid (MDCA), which are known to inhibit phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H) and 4-coumarate-CoA ligase (4CL) respectively, the three early enzymes of phenylpropanoid metabolism, were chosen with the anticipation that selective inhibition of these enzymes in vivo may provide information on the metabolic route to p-hydroxybenzoic acid formation. Supplementation of AOAA (0.2-1.0 mM) and PIP (0.2-1.0 mM) resulted in the reduced accumulation of p-hydroxybenzoic acid in the wall-bound fraction. However, addition of MDCA (0.2-1.25 mM), did not suppress p-hydroxybenzoic acid accumulation but suppressed lignin and total flavonoid accumulation, suggesting that 4CL enzyme activity is not required for p-hydroxybenzoic acid formation. Feeding of elicited hairy roots with phenylalanine, coumaric acid and p-hydroxybenzaldehyde had a stimulatory effect on p-hydroxybenzoic acid accumulation; however, maximum stimulatory effect was shown by p-hydroxybenzaldehyde. This suggests that p-hydroxybenzaldehyde might be the immediate precursor in p-hydroxybenzoic acid biosynthesis. Finally, in vitro conversion of p-coumaric acid to p-hydroxybenzoic acid with p-hydroxybenzaldehyde as intermediate using cell-free extract provided an unequivocal support for CoA-independent and non-beta-oxidative route of p-hydroxybenzoic acid biosynthesis in Daucus carota.

  18. Graphene oxide induces plasma membrane damage, reactive oxygen species accumulation and fatty acid profiles change in Pichia pastoris.

    PubMed

    Zhang, Meng; Yu, Qilin; Liang, Chen; Liu, Zhe; Zhang, Biao; Li, Mingchun

    2016-10-01

    During the past couple of years, graphene nanomaterials were extremely popular among the scientists due to the promising properties in many aspects. Before the materials being well applied, we should first focus on their biosafety and toxicity. In this study, we investigated the toxicity of synthesized graphene oxide (GO) against the model industrial organism Pichia pastoris. We found that the synthesized GO showed dose-dependent toxicity to P. pastoris, through cell membrane damage and intracellular reactive oxygen species (ROS) accumulation. In response to these cell stresses, cells had normal unsaturated fatty acid (UFA) levels but increased contents of polyunsaturated fatty acid (PUFA) with up-regulation of UFA synthesis-related genes on the transcriptional level, which made it overcome the stress under GO attack. Two UFA defective strains (spt23Δ and fad12Δ) were used to demonstrate the results above. Hence, this study suggested a close connection between PUFAs and cell survival against GO.

  19. Utilization of ammonium as a nitrogen source: effects of ambient acidity on growth and nitrogen accumulation by soybean

    NASA Technical Reports Server (NTRS)

    Tolley-Henry, L.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1986-01-01

    Dry matter accumulation of plants utilizing NH4+ as the sole nitrogen source generally is less than that of plants receiving NO3- unless acidity of the root-zone is controlled at a pH of about 6.0. To test the hypothesis that the reduction in growth is a consequence of nitrogen stress within the plant in response to effects of increased acidity during uptake of NH4+ by roots, nonnodulated soybean plants (Glycine max [L.] Merr. cv Ransom) were grown for 24 days in flowing nutrient culture containing 1.0 millimolar NH4+ as the nitrogen source. Acidities of the culture solutions were controlled at pH 6.1, 5.1, and 4.1 +/- 0.1 by automatic additions of 0.01 N H2SO4 or Ca(OH)2. Plants were sampled at intervals of 3 to 4 days for determination of dry matter and nitrogen accumulation. Rates of NH4+ uptake per gram root dry weight were calculated from these data. Net CO2 exchange rates per unit leaf area were measured on attached leaves by infrared gas analysis. When acidity of the culture solution was increased from pH 6.1 to 5.1, dry matter and nitrogen accumulation were reduced by about 40% within 14 days. Net CO2 exchange rates per unit leaf area, however, were not affected, and the decreased growth was associated with a reduction in rates of appearance and expansion of new leaves. The uptake rates of NH4+ per gram root were about 25% lower throughout the 24 days at pH 5.1 than at 6.1. A further increase in solution acidity from pH 5.1 to 4.1 resulted in cessation of net dry matter production and appearance of new leaves within 10 days. Net CO2 exchange rates per unit leaf area declined rapidly until all viable leaves had abscised by 18 days. Uptake rates of NH4+, which were initially about 50% lower at pH 4.1 than at 6.1 continued to decline with time of exposure until net uptake ceased at 10 days. Since these responses also are characteristic of the sequence of responses that occur during onset and progression of a nitrogen stress, they corroborate our hypothesis.

  20. Decreased Membrane Integrity in Aging Typha latifolia L.Pollen (Accumulation of Lysolipids and Free Fatty Acids).

    PubMed Central

    Van Bilsen, DGJL.; Hoekstra, F. A.

    1993-01-01

    Aging of cattail (Typha latifolia L.) pollen was studied at 24[deg]C under conditions of 40 and 75% relative humidity (RH). The decline of viability coincides with increased leakage at imbibition; both processes develop much faster at the higher humidity condition. During aging phospholipids are deesterified and free fatty acids (FFAs) and lysophospholipids (LPLs) accumulate, again, much more rapidly at 75% RH than at 40% RH. The fatty acid composition of the remaining phospholipids hardly changes during aging, which suggests limited involvement of lipid peroxidation in the degradation process. Tests with phospholipase A2 revealed that the saturated fatty acids occur at the sn-1 position of the glycerol backbone of the phospholipids. The fatty acid composition of the LPLs is similar to that of the phospholipids from which they were formed, indicating that the deesterification occurs at random. This favors involvement of free radicals instead of phospholipases in the deesterification process. Liposome studies were carried out to characterize components in the lipid fraction that might account for the leakage associated with aging. Entrapped carboxyfluorescein leaked much more from liposomes when they were partly made up from total lipids from aged pollen than from nonaged pollen. The components causing the leakage were found in both the polar and the neutral lipid fractions. Further purification and subsequent interchanging of the FFAs and LPLs between extracts from aged and nonaged pollen revealed that in neutral lipid extracts the FFAs are entirely responsible for the leakage, whereas in the phospholipid fraction the LPLs are largely responsible for the leakage. The leakage from the liposomes is not caused by fusion. We suggest that the observed loss of viability and increased leakage during aging are due to the nonenzymic accumulation of FFAs and LPLs in the pollen membranes. PMID:12231723

  1. Dormant cancer cells accumulate high protoporphyrin IX levels and are sensitive to 5-aminolevulinic acid-based photodynamic therapy

    PubMed Central

    Nakayama, Taku; Otsuka, Shimpei; Kobayashi, Tatsuya; Okajima, Hodaka; Matsumoto, Kentaro; Hagiya, Yuichiro; Inoue, Keiji; Shuin, Taro; Nakajima, Motowo; Tanaka, Tohru; Ogura, Shun-ichiro

    2016-01-01

    Photodynamic therapy (PDT) and diagnosis (PDD) using 5-aminolevulinic acid (ALA) to drive the production of an intracellular photosensitizer, protoporphyrin IX (PpIX), are in common clinical use. However, the tendency to accumulate PpIX is not well understood. Patients with cancer can develop recurrent metastatic disease with latency periods. This pause can be explained by cancer dormancy. Here we created uniformly sized PC-3 prostate cancer spheroids using a 3D culture plate (EZSPHERE). We demonstrated that cancer cells exhibited dormancy in a cell density-dependent manner not only in spheroids but also in 2D culture. Dormant cancer cells accumulated high PpIX levels and were sensitive to ALA-PDT. In dormant cancer cells, transporter expressions of PEPT1, ALA importer, and ABCB6, an intermediate porphyrin transporter, were upregulated and that of ABCG2, a PpIX exporter, was downregulated. PpIX accumulation and ALA-PDT cytotoxicity were enhanced by G0/G1-phase arrestors in non-dormant cancer cells. Our results demonstrate that ALA-PDT would be an effective approach for dormant cancer cells and can be enhanced by combining with a cell-growth inhibitor. PMID:27857072

  2. Water stress and accumulation of beta-N-oxalyl-L-alpha,beta-diaminopropionic acid in grass pea (Lathyrus sativus).

    PubMed

    Xing, G; Cui, K; Ji, L; Wang, Y; Li, Z

    2001-01-01

    Grass pea seedlings were grown in an irrigated field. Roots of 15-day-old seedlings were treated with PEG, and leaves were studied. With the duration of PEG treatment, changes in the lipid peroxidation and activities of superoxide dismutase, catalase, peroxidase, and glutathione reductase as well as contents of hydrogen peroxide and beta-N-oxalyl-L-alpha,beta-diaminopropionic acid (ODAP) were assayed. The results indicate that with the duration of PEG treatment, activities of superoxide dismutase, peroxidase, and catalase decreased, whereas contents of hydrogen peroxide and ODAP, extent of lipid peroxidation, and activity of glutathione reductase increased. Both diethyldithiocarbamate and aminotriazole strongly inhibit activities of superoxide dismutase and catalase, respectively. At same time, the extent of lipid peroxidation was obviously increased. However, mannitol decreased the extent of lipid peroxidation. Diethyldithiocarbamate, aminotriazole, and mannitol do not affect the accumulation of ODAP. The observations suggest that there is no direct relationship between the accumulation of ODAP and the metabolism of free radicals. In addition, the relationship between water stress and ODAP accumulation in grass pea is discussed.

  3. Accumulation of ricinoleic, lesquerolic, and densipolic acids in seeds of transgenic Arabidopsis plants that express a fatty acyl hydroxylase cDNA from castor bean.

    PubMed Central

    Broun, P; Somerville, C

    1997-01-01

    A cDNA encoding the oleate 12-hydroxylase from castor bean (Ricinus communis L.) has previously been shown to direct the synthesis of small amounts of ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) in seeds of transgenic tobacco plants. Expression of the cDNA under control of the Brassica napus napin promoter in transgenic Arabidopsis thaliana plants resulted in the accumulation of up to 17% of seed fatty acids as ricinoleate and two novel fatty acids that have been identified by gas chromatography-mass spectrometry as lesquerolic (14-hydroxyeicos-cis-11-enoic acid) and densipolic (12-hydroxyoctadec-cis-9,15-dienoic acid) acids. Traces of auricolic acid were also observed. These results suggest that either the castor hydroxylase can utilize oleic acid and eicosenoic acid as substrates for ricinoleic and lesquerolic acid biosynthesis, respectively, or Arabidopsis contains an elongase that accepts ricinoleic acid as a substrate. These observations are also consistent with indirect biochemical evidence that an n-3 desaturase is capable of converting ricinoleic acid to densipolic acid. Expression of the castor hydroxylase also caused enhanced accumulation of oleic acid and a corresponding decrease in the levels of polyunsaturated fatty acids. Since the steady-state level of mRNA for the oleate-12 desaturase was not affected, it appears that the presence of the hydroxylase, directly or indirectly, causes posttranscriptional inhibition of desaturation. PMID:9085577

  4. The Acute Effect of Humic Acid on Iron Accumulation in Rats.

    PubMed

    Cagin, Yasir Furkan; Sahin, N; Polat, A; Erdogan, M A; Atayan, Y; Eyol, E; Bilgic, Y; Seckin, Y; Colak, C

    2016-05-01

    Free iron leads to the formation of pro-oxidant reactive oxygen species (ROS). Humic acids (HAs) enhance permeability of cellular wall and act as a chelator through electron transferring. This study was designed to test chelator effect of HA on iron as well as its anti-oxidant effect against the iron-induced hepatotoxicity and cardiotoxicity. The rats used were randomly divided into four groups (n = 8/group): group I (the control group); group II (the HA group), humic acid (562 mg/kg) was given over 10 days by oral gavage; group III (the iron group), iron III hydroxide polymaltose (250 mg/kg) was given over 10 days by intraperitoneal route; and group IV (the HA plus iron group), received the iron (similar to group II) plus humic acid (similar to those in groups II and III) group. Blood and two tissue samples both from liver and heart were obtained for biochemical and histopathological evaluations. Iron deposition, the iron-induced hepatotoxicity, and cardiotoxicity were demonstrated by histopathological and biochemical manner. However, no significant differences were observed in the serum biochemical values and the histopathological results among the iron and the HA plus iron groups in the liver tissue but not in the heart tissue. The protective effects of humic acid against iron-induced cardiotoxicity were shown but not against hepatotoxicity in our study.

  5. Combined nitrogen limitation and cadmium stress stimulate total carbohydrates, lipids, protein and amino acid accumulation in Chlorella vulgaris (Trebouxiophyceae).

    PubMed

    Chia, Mathias Ahii; Lombardi, Ana Teresa; da Graça Gama Melão, Maria; Parrish, Christopher C

    2015-03-01

    Metals have interactive effects on the uptake and metabolism of nutrients in microalgae. However, the effect of trace metal toxicity on amino acid composition of Chlorella vulgaris as a function of varying nitrogen concentrations is not known. In this research, C. vulgaris was used to investigate the influence of cadmium (10(-7) and 2.0×10(-8)molL(-1) Cd) under varying nitrogen (2.9×10(-6), 1.1×10(-5) and 1.1×10(-3)molL(-1)N) concentrations on its growth rate, biomass and biochemical composition. Total carbohydrates, total proteins, total lipids, as well as individual amino acid proportions were determined. The combination of Cd stress and N limitation significantly inhibited growth rate and cell density of C. vulgaris. However, increasing N limitation and Cd stress stimulated higher dry weight and chlorophyll a production per cell. Furthermore, biomolecules like total proteins, carbohydrates and lipids increased with increasing N limitation and Cd stress. Ketogenic and glucogenic amino acids were accumulated under the stress conditions investigated in the present study. Amino acids involved in metal chelation like proline, histidine and glutamine were significantly increased after exposure to combined Cd stress and N limitation. We conclude that N limitation and Cd stress affects the physiology of C. vulgaris by not only decreasing its growth but also stimulating biomolecule production.

  6. Amino acid accumulation in frog muscle. II. Are cycloleucine fluxes consistent with an adsorption model for concentrative uptake of amino acid?

    PubMed

    Neville, M C

    1975-03-25

    Cycloleucine accumulation by frog muscle was studied at 0 degrees C and 25 degrees C. At external concentrations less than 5 mM the distribution ratio of cycloleucine is higher at 0 degrees C. At concentrations greater than 5 mM the converse is true due to apparent exclusion of cycloleucine from a larger portion of the cell water at 0 degrees C than at 25 degrees C. The steady state data are consistent with an adsorption model for amino acid accumulation. Flux studies provide a means to rule out this model if all the possible rate-limiting steps in the movement of amino acid into and out of the cell are considered. These steps include intra-cytoplasmic diffusion, desorption from cytoplasmic or membrane sites and passage through the cell membrane. The assumption is made that the rate-limiting step for influx and efflux is the same, allowing the use of either influx or efflux data to examine the model. Diffusion-limited flux is ruled out on the basis of "influx profile analysis" of the time course of cycloleucine entry at both 0 degrees C and 25 degrees C. At least 95% of all intracellular cycloleucine leaves frog muscle cells with a single exponential time course at both 0 degrees C and 25 degrees C. The rate constant of efflux does not vary with cellular concentration. These findings are shown to be incompatible with desorption-limited efflux. They are compatible with membrane-limited efflux only if (i) adsorption sites are located on membranes with direct access to the extracellular space and (ii) the rate constant for desorption is equal to the rate constant of membrane-limited efflux of free amino acid. It is considered unlikely that such a coincidence would occur at both 0 degrees C and 25 degrees C. Therefore, an adsorption model for cycloleucine accumulation in frog muscle appears to be untenable.

  7. Assessing accumulation and biliary excretion of naphthenic acids in yellow perch exposed to oil sands-affected waters.

    PubMed

    van den Heuvel, Michael R; Hogan, Natacha S; MacDonald, Gillian Z; Berrue, Fabrice; Young, Rozlyn F; Arens, Collin J; Kerr, Russell G; Fedorak, Phillip M

    2014-01-01

    Naphthenic acids are known to be the most prevalent group of organic compounds in oil sands tailings-associated waters. Yellow perch (Perca flavescens) were exposed for four months to oil sands-influenced waters in two experimental systems located on an oil sands lease 30 km north of Fort McMurray Alberta: the Demonstration Pond, containing oil sands tailings capped with natural surface water, and the South Bison Pond, integrating lean oil sands. Yellow perch were also sampled from three lakes: Mildred Lake that receives water from the Athabasca River, Sucker Lake, at the edge of oil sands extraction activity, and Kimowin Lake, a distant reference site. Naphthenic acids were measured in perch muscle tissue using gas chromatography-mass spectrometry (GC-MS). Bile metabolites were measured by GC-MS techniques and by high performance liquid chromatography (HPLC) with fluorescence detection at phenanthrene wavelengths. A method was developed using liquid chromatography-high resolution mass spectrometry (LC-HRMS) to evaluate naphthenic acids in bile. Tissue analysis did not show a pattern of naphthenic acids accumulation in muscle tissue consistent with known concentrations in exposed waters. Bile fluorescence and LC-HRMS methods were capable of statistically distinguishing samples originating from oil sands-influenced waters versus reference lakes. Although the GC-MS and HPLC fluorescence methods were correlated, there were no significant correlations of these methods and the LC-HRMS method. In yellow perch, naphthenic acids from oil sands sources do not concentrate in tissue at a measurable amount and are excreted through a biliary route. LC-HRMS was shown to be a highly sensitive, selective and promising technique as an indicator of exposure of biota to oil sands-derived naphthenic acids.

  8. Palmitic Acid Reduces Circulating Bone Formation Markers in Obese Animals and Impairs Osteoblast Activity via C16-Ceramide Accumulation.

    PubMed

    Alsahli, Ahmad; Kiefhaber, Kathryn; Gold, Tziporah; Muluke, Munira; Jiang, Hongfeng; Cremers, Serge; Schulze-Späte, Ulrike

    2016-05-01

    Obesity and impaired lipid metabolism increase circulating and local fatty acid (FA) levels. Our previous studies showed that a high high-saturated -fat diet induced greater bone loss in mice than a high high-unsaturated-fat diet due to increased osteoclast numbers and activity. The impact of elevated FA levels on osteoblasts is not yet clear. We induced obesity in 4 week old male mice using a palmitic acid (PA)- or oleic acid (OA)-enriched high fat high-fat diet (HFD) (20 % of calories from FA), and compared them to mice on a normal (R) caloric diet (10 % of calories from FA). We collected serum to determine FA and bone metabolism marker levels. Primary osteoblasts were isolated; cultured in PA, OA, or control (C) medium; and assessed for mineralization activity, gene expression, and ceramide levels. Obese animals in the PA and OA groups had significantly lower serum levels of bone formation markers P1NP and OC compared to normal weight animals (*p < 0.001), with the lowest marker levels in animals on an PA-enriched HFD (*p < 0.001). Accordingly, elevated levels of PA significantly reduced osteoblast mineralization activity in vitro (*p < 0.05). Elevated PA intake significantly increased C16 ceramide accumulation. This accumulation was preventable through inhibition of SPT2 (serine palmitoyl transferase 2) using myriocin. Elevated levels of PA reduce osteoblast function in vitro and bone formation markers in vivo. Our findings suggest that saturated PA can compromise bone health by affecting osteoblasts, and identify a potential mechanism through which obesity promotes bone loss.

  9. Ca2+ accumulation into acidic organelles mediated by Ca2+- and vacuolar H+-ATPases in human platelets

    PubMed Central

    2005-01-01

    Most physiological agonists increase cytosolic free [Ca2+]c (cytosolic free Ca2+ concentration) to regulate a variety of cellular processes. How different stimuli evoke distinct spatiotemporal Ca2+ responses remains unclear, and the presence of separate intracellular Ca2+ stores might be of great functional relevance. Ca2+ accumulation into intracellular compartments mainly depends on the activity of Ca2+- and H+-ATPases. Platelets present two separate Ca2+ stores differentiated by the distinct sensitivity to thapsigargin and TBHQ [2,5-di-(t-butyl)-1,4-hydroquinone]. Although one store has long been identified as the dense tubular system, the nature of the TBHQ-sensitive store remains uncertain. Treatment of platelets with GPN (glycylphenylalanine-2-naphthylamide) impaired Ca2+ release by TBHQ and reduced that evoked by thrombin. In contrast, GPN did not modify Ca2+ mobilization stimulated by ADP or AVP ([arginine]vasopressin). Treatment with nigericin, a proton carrier, and bafilomycin A1, an inhibitor of the vacuolar H+-ATPase, to dissipate the proton gradient into acidic organelles induces a transient increase in [Ca2+]c that was abolished by previous treatment with the SERCA (sarcoplasmic/endoplasmic-reticulum Ca2+-ATPase) 3 inhibitor TBHQ. Depleted acidic stores after nigericin or bafilomycin A1 were refilled by SERCA 3. Thrombin, but not ADP or AVP, reduces the rise in [Ca2+]c evoked by nigericin and bafilomycin A1. Our results indicate that the TBHQ-sensitive store in human platelets is an acidic organelle whose Ca2+ accumulation is regulated by both Ca2+- and vacuolar H+-ATPases. PMID:15847604

  10. The plant immunity inducer pipecolic acid accumulates in the xylem sap and leaves of soybean seedlings following Fusarium virguliforme infection.

    PubMed

    Abeysekara, Nilwala S; Swaminathan, Sivakumar; Desai, Nalini; Guo, Lining; Bhattacharyya, Madan K

    2016-02-01

    The causal agent of the soybean sudden death syndrome (SDS), Fusarium virguliforme, remains in infected roots and secretes toxins to cause foliar SDS. In this study we investigated the xylem sap, roots, and leaves of F. virguliforme-infected and -uninfected soybean seedlings for any changes in a set of over 3,000 metabolites following pathogen infection by conducting GC/MS and LC/MS/MS, and detected 273 biochemicals. Levels of many intermediates of the TCA cycle were reduced suggesting suppression of this metabolic pathway by the pathogen. There was an increased accumulation of peroxidated lipids in leaves of F. virguliforme-infected plants suggesting possible involvement of free radicals and lipoxygenases in foliar SDS development. Levels of both isoflavone conjugates and isoflavonoid phytoalexins were decreased in infected roots suggesting degradation of these metabolites by the pathogen to promote root necrosis. The levels of the plant immunity inducer pipecolic acid (Pip) and the plant hormone salicylic acid (SA) were significantly increased in xylem sap (in case of Pip) and leaves (in case of both Pip and SA) of F. virguliforme-infected soybean plants compared to the control plants. This suggests a major signaling role of Pip in inducing host defense responses in above ground parts of the F. virguliforme-infected soybean. Increased accumulation of pipecolic acid in foliar tissues was associated with the induction of GmALD1, the soybean homolog of Arabidopsis ALD1. This metabolomics study generated several novel hypotheses for studying the mechanisms of SDS development in soybean.

  11. Acid-tolerant microaerophilic Fe(II)-oxidizing bacteria promote Fe(III)-accumulation in a fen.

    PubMed

    Lüdecke, Claudia; Reiche, Marco; Eusterhues, Karin; Nietzsche, Sandor; Küsel, Kirsten

    2010-10-01

    The ecological importance of Fe(II)-oxidizing bacteria (FeOB) at circumneutral pH is often masked in the presence of O(2) where rapid chemical oxidation of Fe(II) predominates. This study addresses the abundance, diversity and activity of microaerophilic FeOB in an acidic fen (pH ∼ 5) located in northern Bavaria, Germany. Mean O(2) penetration depth reached 16 cm where the highest dissolved Fe(II) concentrations (up to 140 µM) were present in soil water. Acid-tolerant FeOB cultivated in gradient tubes were most abundant (10(6) cells g(-1) peat) at the 10-20 cm depth interval. A stable enrichment culture was active at up to 29% O(2) saturation and Fe(III) accumulated 1.6 times faster than in abiotic controls. An acid-tolerant, microaerophilic isolate (strain CL21) was obtained which was closely related to the neutrophilic, lithoautotrophic FeOB Sideroxydans lithotrophicus strain LD-1. CL21 oxidized Fe(II) between pH 4 and 6.0, and produced nanoscale-goethites with a clearly lower mean coherence length (7 nm) perpendicular to the (110) plane than those formed abiotically (10 nm). Our results suggest that an acid-tolerant population of FeOB is thriving at redox interfaces formed by diffusion-limited O(2) transport in acidic peatlands. Furthermore, this well-adapted population is successfully competing with chemical oxidation and thereby playing an important role in the microbial iron cycle.

  12. 1-FFT amino acids involved in high DP inulin accumulation in Viguiera discolor

    PubMed Central

    De Sadeleer, Emerik; Vergauwen, Rudy; Struyf, Tom; Le Roy, Katrien; Van den Ende, Wim

    2015-01-01

    Fructans are important vacuolar reserve carbohydrates with drought, cold, ROS and general abiotic stress mediating properties. They occur in 15% of all flowering plants and are believed to display health benefits as a prebiotic and dietary fiber. Fructans are synthesized by specific fructosyltransferases and classified based on the linkage type between fructosyl units. Inulins, one of these fructan types with β(2-1) linkages, are elongated by fructan:fructan 1-fructosyltransferases (1-FFT) using a fructosyl unit from a donor inulin to elongate the acceptor inulin molecule. The sequence identity of the 1-FFT of Viguiera discolor (Vd) and Helianthus tuberosus (Ht) is 91% although these enzymes produce distinct fructans. The Vd 1-FFT produces high degree of polymerization (DP) inulins by preferring the elongation of long chain inulins, in contrast to the Ht 1-FFT which prefers small molecules (DP3 or 4) as acceptor. Since higher DP inulins have interesting properties for industrial, food and medical applications, we report here on the influence of two amino acids on the high DP inulin production capacity of the Vd 1-FFT. Introducing the M19F and H308T mutations in the active site of the Vd 1-FFT greatly reduces its capacity to produce high DP inulin molecules. Both amino acids can be considered important to this capacity, although the double mutation had a much higher impact than the single mutations. PMID:26322058

  13. 1-FFT amino acids involved in high DP inulin accumulation in Viguiera discolor.

    PubMed

    De Sadeleer, Emerik; Vergauwen, Rudy; Struyf, Tom; Le Roy, Katrien; Van den Ende, Wim

    2015-01-01

    Fructans are important vacuolar reserve carbohydrates with drought, cold, ROS and general abiotic stress mediating properties. They occur in 15% of all flowering plants and are believed to display health benefits as a prebiotic and dietary fiber. Fructans are synthesized by specific fructosyltransferases and classified based on the linkage type between fructosyl units. Inulins, one of these fructan types with β(2-1) linkages, are elongated by fructan:fructan 1-fructosyltransferases (1-FFT) using a fructosyl unit from a donor inulin to elongate the acceptor inulin molecule. The sequence identity of the 1-FFT of Viguiera discolor (Vd) and Helianthus tuberosus (Ht) is 91% although these enzymes produce distinct fructans. The Vd 1-FFT produces high degree of polymerization (DP) inulins by preferring the elongation of long chain inulins, in contrast to the Ht 1-FFT which prefers small molecules (DP3 or 4) as acceptor. Since higher DP inulins have interesting properties for industrial, food and medical applications, we report here on the influence of two amino acids on the high DP inulin production capacity of the Vd 1-FFT. Introducing the M19F and H308T mutations in the active site of the Vd 1-FFT greatly reduces its capacity to produce high DP inulin molecules. Both amino acids can be considered important to this capacity, although the double mutation had a much higher impact than the single mutations.

  14. Leachate flush strategies for managing volatile fatty acids accumulation in leach-bed reactors.

    PubMed

    Riggio, S; Torrijos, M; Vives, G; Esposito, G; van Hullebusch, E D; Steyer, J P; Escudié, R

    2017-05-01

    In anaerobic leach-bed reactors (LBRs) co-digesting an easily- and a slowly-degradable substrate, the importance of the leachate flush both on extracting volatile fatty acids (VFAs) at the beginning of newly-started batches and on their consumption in mature reactors was tested. Regarding VFA extraction three leachate flush-rate conditions were studied: 0.5, 1 and 2Lkg(-1)TSd(-1). Results showed that increasing the leachate flush-rate during the acidification phase is essential to increase degradation kinetics. After this initial phase, leachate injection is less important and the flush-rate could be reduced. The injection in mature reactors of leachate with an acetic acid concentration of 5 or 10gL(-1) showed that for an optimized VFA consumption in LBRs, VFAs should be provided straight after the methane production peak in order to profit from a higher methanogenic activity, and every 6-7h to maintain a high biogas production rate.

  15. A Method for the Measurement of Nitrous Acid Flux Using Relaxed Eddy Accumulation

    NASA Astrophysics Data System (ADS)

    Bertman, S.; Marchewka, M.; King, J.

    2003-12-01

    HONO has recently received renewed attention as a byproduct of condensed nitrogen photolysis and as a potential atmospheric radical source. In particular, several recent accounts suggesting a photochemical source in forests have lead us to develop a method for assessing nitrous acid flux above a hardwood forest in northern Michigan. The technique was based on nitrous acid in ambient air being scrubbed into a 1mM phosphate buffer that was then derivatized into a light absorbing complex. A separate scrubbing system was used for updrafts and downdrafts after the air had been separated through Teflon valves according to input from a sonic anemometer. The detection of the complex was performed via UV absorption through a capillary flowthrough cell. Detection limit for this analytical method is around 10 pptv. Derivatized solution from each flow system was injected into the capillary cell via an 8-port valve with two sample loops. Each sample loop was injected as soon as it filled, which allowed measurement of all of the scrubbed material in each flow system. Laboratory tests were performed to assess the accuracy and suitability of this method. The field worthiness of the instrument was determined during the summer of 2003 at the University of Michigan Biological Station in northern Michigan where it was placed on top of a 35m tower above a forest canopy.

  16. Exposure to TBT increases accumulation of lipids and alters fatty acid homeostasis in the ramshorn snail Marisa cornuarietis.

    PubMed

    Janer, Gemma; Navarro, Juan Carlos; Porte, Cinta

    2007-09-01

    Recent studies have shown that organotin compounds affect lipid homeostasis in vertebrates, probably through interaction with RXR and/or PPARgamma receptors. Molluscs are sensitive species to the toxic effects of tributyltin (TBT), particularly to masculinization, and TBT has been recently shown to bind to molluscs RXR. Thus, we hypothesized that exposure to TBT could affect lipid homeostasis in the ramshorn snail Marisa cornuarietis. For comparative purposes, the synthetic androgen methyl-testosterone (MT) was included in the study due to its masculinization effects, but its lack of binding to the RXR receptor. M. cornuarietis was exposed to different concentrations of TBT (30, 125, 500 ng/L as Sn) and MT (30, 300 ng/L) for 100 days. Females exposed to 500 ng/L TBT showed increased percentage of lipids and increased levels of fatty acids in the digestive gland/gonad complex (2- to 3-fold). In addition, fatty acid profiles were altered in both males and females exposed to 125 and 500 ng/L TBT. These effects were not observed in females exposed to MT. Overall, this work suggest that TBT acts as a potent inducer of lipid and fatty acid accumulation in M. cornuarietis as shown in vertebrate studies earlier, and that sex differences in sensitivity do exist.

  17. Trichoderma inoculation augments grain amino acids and mineral nutrients by modulating arsenic speciation and accumulation in chickpea (Cicer arietinum L.).

    PubMed

    Tripathi, Pratibha; Singh, Poonam C; Mishra, Aradhana; Tripathi, Rudra D; Nautiyal, Chandra S

    2015-07-01

    Trichoderma reesei is an industrially important fungi which also imparts stress tolerance and plant growth promotion in various crops. Arsenic (As) contamination of field soils is one of the challenging problems in agriculture, posing potential threats for both human health and the environment. Plants in association with microbes are a liable method to improve metal tolerance and enhance crop productivity. Chickpea (Cicer arietinum L.), is an important grain legume providing cheap source of protein in semi-arid regions including As affected areas. In this study we report the role of T. reesei NBRI 0716 (NBRI 0716) in supporting chickpea growth and improving soil quality in As simulated conditions. NBRI 0716 modulated the As speciation and its availability to improve grain yield and quality (amino acids and mineral content) in chickpea (C. arietinum L.) plants grown in As spiked soil (100 mg As kg(-1) soil). Arsenic accumulation and speciation results indicate that arsenate [As(V)] was the dominant species in chickpea seeds and rhizosphere soil. The Trichoderma reduced total grain inorganic As (Asi) by 66% and enhanced dimethylarsonic acid (DMA) and monomethylarsinic acid (MMA) content of seed and rhizosphere soil. The results indicate a probable role of NBRI 0716 in As methylation as the possible mechanism for maneuvering As stress in chickpea. Analysis of functional diversity using carbon source utilization (Biolog) showed significant difference in diversity and evenness indices among the soil microbial rhizosphere communities. Microbial diversity loss caused by As were prevented in the presence of Trichoderma NBRI 0716.

  18. Inactivation of the lys7 gene, encoding saccharopine reductase in Penicillium chrysogenum, leads to accumulation of the secondary metabolite precursors piperideine-6-carboxylic acid and pipecolic acid from alpha-aminoadipic acid.

    PubMed

    Naranjo, Leopoldo; Martín de Valmaseda, Eva; Casqueiro, Javier; Ullán, Ricardo V; Lamas-Maceiras, Mónica; Bañuelos, Oscar; Martín, Juan F

    2004-02-01

    Pipecolic acid serves as a precursor of the biosynthesis of the alkaloids slaframine and swainsonine (an antitumor agent) in some fungi. It is not known whether other fungi are able to synthesize pipecolic acid. Penicillium chrysogenum has a very active alpha-aminoadipic acid pathway that is used for the synthesis of this precursor of penicillin. The lys7 gene, encoding saccharopine reductase in P. chrysogenum, was target inactivated by the double-recombination method. Analysis of a disrupted strain (named P. chrysogenum SR1-) showed the presence of a mutant lys7 gene lacking about 1,000 bp in the 3'-end region. P. chrysogenum SR1- lacked saccharopine reductase activity, which was recovered after transformation of this mutant with the intact lys7 gene in an autonomously replicating plasmid. P. chrysogenum SR1- was a lysine auxotroph and accumulated piperideine-6-carboxylic acid. When mutant P. chrysogenum SR1- was grown with L-lysine as the sole nitrogen source and supplemented with DL-alpha-aminoadipic acid, a high level of pipecolic acid accumulated intracellularly. A comparison of strain SR1- with a lys2-defective mutant provided evidence showing that P. chrysogenum synthesizes pipecolic acid from alpha-aminoadipic acid and not from L-lysine catabolism.

  19. Inhibition of norsolorinic acid accumulation to Aspergillus parasiticus by marine actinomycetes

    NASA Astrophysics Data System (ADS)

    Yan, Peisheng; Shi, Cuijuan; Shen, Jihong; Wang, Kai; Gao, Xiujun; Li, Ping

    2014-11-01

    Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods. Among them, three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp. by 16S rRNA gene sequencing analysis. The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate, and the activities of the extracts were determined by tip culture assay. The assay results show that both extracts inhibited mycelium growth and toxin production, and the inhibitory activities of the extracts increased as their concentrations increased. The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins, and that these bacteria could be used as novel biopesticides against mycotoxins.

  20. The Citrus transcription factor, CitERF13, regulates citric acid accumulation via a protein-protein interaction with the vacuolar proton pump, CitVHA-c4

    PubMed Central

    Li, Shao-jia; Yin, Xue-ren; Xie, Xiu-lan; Allan, Andrew C.; Ge, Hang; Shen, Shu-ling; Chen, Kun-song

    2016-01-01

    Organic acids are essential to fruit flavor. The vacuolar H+ transporting adenosine triphosphatase (V-ATPase) plays an important role in organic acid transport and accumulation. However, less is known of V-ATPase interacting proteins and their relationship with organic acid accumulation. The relationship between V-ATPase and citric acid was investigated, using the citrus tangerine varieties ‘Ordinary Ponkan (OPK)’ and an early maturing mutant ‘Zaoshu Ponkan (ZPK)’. Five V-ATPase genes (CitVHA) were predicted as important to citric acid accumulation. Among the genes, CitVHA-c4 was observed, using a yeast two-hybrid screen, to interact at the protein level with an ethylene response factor, CitERF13. This was verified using bimolecular fluorescence complementation assays. A similar interaction was also observed between Arabidopsis AtERF017 (a CitERF13 homolog) and AtVHA-c4 (a CitVHA-c4 homolog). A synergistic effect on citric acid levels was observed between V-ATPase proteins and interacting ERFs when analyzed using transient over-expression in tobacco and Arabidopsis mutants. Furthermore, the transcript abundance of CitERF13 was concomitant with CitVHA-c4. CitERF13 or AtERF017 over-expression leads to significant citric acid accumulation. This accumulation was abolished in an AtVHA-c4 mutant background. ERF-VHA interactions appear to be involved in citric acid accumulation, which was observed in both citrus and Arabidopsis. PMID:26837571

  1. 5-Aminolevulinic acid-induced protoporphyrin-IX accumulation and associated phototoxicity in macrophages and oral cancer cell lines.

    PubMed

    Sharma, Sulbha; Jajoo, Anjana; Dube, Alok

    2007-09-25

    Studies were carried out on 5-aminolevulinic acid (ALA)-induced protoporphyrin (PpIX) synthesis in mice peritoneal macrophages and two human oral squamous cell carcinoma (OSCC) cell lines NT8e and 4451. Cells were treated with 200 microg/ml ALA for 15 h and PpIX accumulation was monitored by spectrofluorometry and phototoxicity to red light (630+/-20 nm) was measured by MTT assay. PpIX accumulation was higher in macrophages as compared to OSCC cells under both normal serum concentration (10%) and conditions of serum depletion. The results on phototoxicity measurements correlated well with the levels of PpIX accumulation in both macrophages and cancer cells. While red light caused 20% phototoxicity in macrophages, no phototoxicity was seen in 4451 cells at 10% serum. Decrease in serum concentration to 5% and 1% led to higher phototoxicity corresponding to 40% and 70% in macrophages and 10% and 15% in 4451 cells. Similar results were obtained in NT8e cell line. Propidium iodide staining followed by fluorescence microscopic observations on photodynamically treated co-culture of murine or human macrophages and cancer cells showed selective damage to macrophages. These results suggest that in OSCC, macrophages would contribute more to tumor PpIX level than tumor cells themselves and PDT may lead to selective killing of macrophages at the site of treatment. Since macrophages are responsible for production and secretion of various tumor growth mediators, the effect of selective macrophage killing on the outcome of PDT would be significant.

  2. Effects of salicylic acid on thermotolerance and cardenolide accumulation under high temperature stress in Digitalis trojana Ivanina.

    PubMed

    Cingoz, Gunce Sahin; Gurel, Ekrem

    2016-08-01

    Long periods of high temperature or transitory increased temperature, a widespread agricultural problem, may lead to a drastic reduction in economic yield, affecting plant growth and development in many areas of the world. Heat stress causes many anatomical and physiological changes in plants. Its unfavorable effects can be alleviated by thermotolerance induced by exogenous application of plant growth regulators and osmoprotectants or by gradual application of temperature stress. Digitalis trojana Ivanina is an important medicinal plant species well known mainly for its cardenolides. The production of cardenolides via traditional agriculture is commercially inadequate. In this study, elicitation strategies were employed for improving crop thermotolerance and accumulation of cardenolides. For these purposes, the effects of salicylic acid (SA) and/or high temperature treatments in inducing cardenolide accumulation and thermotolerance were tested in callus cultures of D. trojana. Considerable increases in the production of cardenolides (up to 472.28 μg.g(-1) dry weight, dw) and induction of thermotolerance capacity were observed when callus cultures were exposed to high temperature for 2 h after pretreating with SA. High temperature treatments (2 h and 4 h) caused a marked reduction in superoxide dismutase (SOD; EC 1.15.1.1) and catalase (CAT; EC 1.11.1.6) activities, while SA pretreatment increased their activities. High temperature and/or SA appeared to increase the levels of proline, total phenolic, and flavonoid content. Elevated phenolic accumulation could be associated with increased stress protection. These results indicated that SA treatments induced synthesis of antioxidants and cardenolides, which may play a significant role in resistance to high temperature stress.

  3. Brain manganese accumulation is inversely related to gamma-amino butyric acid uptake in male and female rats.

    PubMed

    Anderson, Joel G; Cooney, Paula T; Erikson, Keith M

    2007-01-01

    Iron (Fe) is an essential trace metal involved in numerous cellular processes. Iron deficiency (ID) is reported as the most prevalent nutritional problem worldwide. Increasing evidence suggests that ID is associated with altered neurotransmitter metabolism and a risk factor for manganese (Mn) neurotoxicity. Though recent studies have established differences in which the female brain responds to ID-related neurochemical alterations versus the male brain, little is known about the interactions of dietary ID, Mn exposure, and sex on gamma-amino butyric acid (GABA). Male and female Sprague-Dawley rats were randomly divided into four dietary treatment groups: control (CN), control/Mn supplemented, ID, and ID/Mn supplemented. After 6 weeks of treatment, both ID diets caused a highly significant decrease in Fe concentrations across all brain regions compared to CN in both sexes. Both ID and Mn supplementation led to significant accumulation of Mn across all brain regions in both sexes. There was no main effect of sex on Fe or Mn accumulation. Striatal synaptosomes were utilized to examine the effect of dietary intervention on (3)H-GABA uptake. At 4 weeks, there was a significant correlation between Fe concentration and (3)H-GABA uptake in male rats (p < 0.05). At 6 weeks, there was a significant inverse correlation between Mn concentration and (3)H-GABA uptake in male and female rats and a postitive correlation between Fe concentration and (3)H-GABA uptake in female rats (p < 0.05). In conclusion, ID-associated Mn accumulation is similar in both sexes, with Mn levels affecting GABA uptake in both sexes in a comparable fashion.

  4. Accumulation of Phenolic Compounds and Expression Profiles of Phenolic Acid Biosynthesis-Related Genes in Developing Grains of White, Purple, and Red Wheat.

    PubMed

    Ma, Dongyun; Li, Yaoguang; Zhang, Jian; Wang, Chenyang; Qin, Haixia; Ding, Huina; Xie, Yingxin; Guo, Tiancai

    2016-01-01

    Polyphenols in whole grain wheat have potential health benefits, but little is known about the expression patterns of phenolic acid biosynthesis genes and the accumulation of phenolic acid compounds in different-colored wheat grains. We found that purple wheat varieties had the highest total phenolic content (TPC) and antioxidant activity. Among phenolic acid compounds, bound ferulic acid, vanillic, and caffeic acid levels were significantly higher in purple wheat than in white and red wheat, while total soluble phenolic acid, soluble ferulic acid, and vanillic acid levels were significantly higher in purple and red wheat than in white wheat. Ferulic acid and syringic acid levels peaked at 14 days after anthesis (DAA), whereas p-coumaric acid and caffeic acid levels peaked at 7 DAA, and vanillic acid levels gradually increased during grain filling and peaked near ripeness (35 DAA). Nine phenolic acid biosynthesis pathway genes (TaPAL1, TaPAL2, TaC3H1, TaC3H2, TaC4H, Ta4CL1, Ta4CL2, TaCOMT1, and TaCOMT2) exhibited three distinct expression patterns during grain filling, which may be related to the different phenolic acids levels. White wheat had higher phenolic acid contents and relatively high gene expression at the early stage, while purple wheat had the highest phenolic acid contents and gene expression levels at later stages. These results suggest that the expression of phenolic acid biosynthesis genes may be closely related to phenolic acids accumulation.

  5. Accumulation of Phenolic Compounds and Expression Profiles of Phenolic Acid Biosynthesis-Related Genes in Developing Grains of White, Purple, and Red Wheat

    PubMed Central

    Ma, Dongyun; Li, Yaoguang; Zhang, Jian; Wang, Chenyang; Qin, Haixia; Ding, Huina; Xie, Yingxin; Guo, Tiancai

    2016-01-01

    Polyphenols in whole grain wheat have potential health benefits, but little is known about the expression patterns of phenolic acid biosynthesis genes and the accumulation of phenolic acid compounds in different-colored wheat grains. We found that purple wheat varieties had the highest total phenolic content (TPC) and antioxidant activity. Among phenolic acid compounds, bound ferulic acid, vanillic, and caffeic acid levels were significantly higher in purple wheat than in white and red wheat, while total soluble phenolic acid, soluble ferulic acid, and vanillic acid levels were significantly higher in purple and red wheat than in white wheat. Ferulic acid and syringic acid levels peaked at 14 days after anthesis (DAA), whereas p-coumaric acid and caffeic acid levels peaked at 7 DAA, and vanillic acid levels gradually increased during grain filling and peaked near ripeness (35 DAA). Nine phenolic acid biosynthesis pathway genes (TaPAL1, TaPAL2, TaC3H1, TaC3H2, TaC4H, Ta4CL1, Ta4CL2, TaCOMT1, and TaCOMT2) exhibited three distinct expression patterns during grain filling, which may be related to the different phenolic acids levels. White wheat had higher phenolic acid contents and relatively high gene expression at the early stage, while purple wheat had the highest phenolic acid contents and gene expression levels at later stages. These results suggest that the expression of phenolic acid biosynthesis genes may be closely related to phenolic acids accumulation. PMID:27148345

  6. Effect of humic acid-based amendments with foliar application of Zn and Se on Cd accumulation in tobacco.

    PubMed

    Yu, Yao; Wan, Yanan; Wang, Qi; Li, Huafen

    2017-04-01

    The smoke of tobacco is a major source of exposure to Cd in humans and therefore it is urgent to find a way to a method to reduce Cd accumulation in tobacco. A four-month tobacco pot experiment was conducted to investigate the effects of two base treatments (humic acid-based amendments) and two foliar treatments (Zn and Se) on Cd uptake by tobacco. The results showed that Cd in tobacco was mainly transferred into leaves, which could be significantly reduced by both applied amendments. The Cd contents in leaves were reduced by up to 67%. Foliar Zn alone significantly decreased Cd contents in leaves while foliar Se slightly increased them. When base and foliar treatments were combined, base treatments had dominant effects but those of foliar treatments were not distinct. The applied amendments did reduce Cd contents in all the parts of tobacco and the translocation into leaves and they were more effective than foliar Zn and Se.

  7. Gibberellic acid alleviates cadmium toxicity by reducing nitric oxide accumulation and expression of IRT1 in Arabidopsis thaliana.

    PubMed

    Zhu, Xiao Fang; Jiang, Tao; Wang, Zhi Wei; Lei, Gui Jie; Shi, Yuan Zhi; Li, Gui Xin; Zheng, Shao Jian

    2012-11-15

    Gibberellic acid (GA) is involved in not only plant growth and development but also plant responses to abiotic stresses. Here it was found that treating the plants with GA concentrations from 0.1 to 5 μM for 24 h had no obvious effect on root elongation in the absence of cadmium (Cd), whereas in the presence of Cd2+, GA at 5 μM improved root growth, reduced Cd content and lipid peroxidation in the roots, indicating that GA can partially alleviate Cd toxicity. Cd2+ increased nitric oxide (NO) accumulation in the roots, but GA remarkably reduced it, and suppressed the up-regulation of the expression of IRT1. In contrary, the beneficial effect of GA on alleviating Cd toxicity was not observed in an IRT1 knock-out mutant irt1, suggesting the involvement of IRT1 in Cd2+ absorption. Furthermore, the GA-induced reduction of NO and Cd content can also be partially reversed by the application of a NO donor (S-nitrosoglutathione [GSNO]). Taken all these together, the results showed that GA-alleviated Cd toxicity is mediated through the reduction of the Cd-dependent NO accumulation and expression of Cd2+ uptake related gene-IRT1 in Arabidopsis.

  8. Free mycolic acid accumulation in the cell wall of the mce1 operon mutant strain of Mycobacterium tuberculosis.

    PubMed

    Cantrell, Sally A; Leavell, Michael D; Marjanovic, Olivera; Iavarone, Anthony T; Leary, Julie A; Riley, Lee W

    2013-10-01

    The lipid-rich cell wall of Mycobacterium tuberculosis, the agent of tuberculosis, serves as an effective barrier against many chemotherapeutic agents and toxic host cell effector molecules, and it may contribute to the mechanism of persistence. Mycobacterium tuberculosis strains mutated in a 13-gene operon called mce1, which encodes a putative ABC lipid transporter, induce aberrant granulomatous response in mouse lungs. Because of the postulated role of the mce1 operon in lipid importation, we compared the cell wall lipid composition of wild type and mce1 operon mutant M. tuberculosis H37Rv strains. High resolution mass spectrometric analyses of the mce1 mutant lipid extracts showed unbound mycolic acids to accumulate in the cell wall. Quantitative analysis revealed a 10.7 fold greater amount of free mycolates in the mutant compared to that of the wild type strain. The free mycolates were comprised of alpha, methoxy and keto mycolates in the ratio 1:0.9:0.6, respectively. Since the mce1 operon is regulated in vivo, the free mycolates that accumulate during infection may serve as a barrier for M. tuberculosis against toxic products and contribute to the pathogen's persistence.

  9. Lead accumulation and depression of delta-aminolevulinic acid dehydratase (ALAD) in young birds fed automotive waste oil

    USGS Publications Warehouse

    Eastin, W.C.; Hoffman, D.J.; O'Leary, C.T.

    1983-01-01

    The effects of a 3-week dietary exposure to automotive waste crankcase oil (WCO) were examined in 1-week-old mallard (Anas platyrhynchos) ducklings and pheasant (Phasianus colchicus) chicks. Treatment groups consisted of birds exposed to 0.5, 1.5, or 4.5% WCO, to 4.5% clean crankcase oil (CCO), or untreated controls. In both species, red blood cell ALAD activity was significantly inhibited after one week by 50 to 60% in the 0.5% WCO group and by 85 to 90% in the 4.5% WCO group due to the presence of lead. Growth, hematocrit, and hemoglobin were not significantly affected at the end of three weeks. Plasma aspartate aminotransferase (AST) activity was higher in mallards after three weeks of ingesting either 4.5% WCO or 4.5% CCO, suggesting an oil-related effect due to components other than lead. Treatment had no effect on plasma concentration of uric acid, glucose, triglycerides, total protein, or cholesterol. Lead analysis showed the WCO to contain 4,200 ppm Pb and the CCO to contain 2 ppm. Tissues of mallards were examined for accumulation of lead and the order of accumulation at the end of three weeks was kidney > liver > blood ~ brain.

  10. Elevated Carbon Dioxide Altered Morphological and Anatomical Characteristics, Ascorbic Acid Accumulation, and Related Gene Expression during Taproot Development in Carrots

    PubMed Central

    Wu, Xue-Jun; Sun, Sheng; Xing, Guo-Ming; Wang, Guang-Long; Wang, Feng; Xu, Zhi-Sheng; Tian, Yong-Sheng; Hou, Xi-Lin; Xiong, Ai-Sheng

    2017-01-01

    The CO2 concentration in the atmosphere has increased significantly in recent decades and is projected to rise in the future. The effects of elevated CO2 concentrations on morphological and anatomical characteristics, and nutrient accumulation have been determined in several plant species. Carrot is an important vegetable and the effects of elevated CO2 on carrots remain unclear. To investigate the effects of elevated CO2 on the growth of carrots, two carrot cultivars (‘Kurodagosun’ and ‘Deep purple’) were treated with ambient CO2 (a[CO2], 400 μmol⋅mol-1) and elevated CO2 (e[CO2], 3000 μmol⋅mol-1) concentrations. Under e[CO2] conditions, taproot and shoot fresh weights and the root/shoot ratio of carrot significantly decreased as compared with the control group. Elevated CO2 resulted in obvious changes in anatomy and ascorbic acid accumulation in carrot roots. Moreover, the transcript profiles of 12 genes related to AsA biosynthesis and recycling were altered in response to e[CO2]. The ‘Kurodagosun’ and ‘Deep purple’ carrots differed in sensitivity to e[CO2]. The inhibited carrot taproot and shoot growth treated with e[CO2] could partly lead to changes in xylem development. This study provided novel insights into the effects of e[CO2] on the growth and development of carrots. PMID:28119712

  11. Fatty acid synthase 2 contributes to diapause preparation in a beetle by regulating lipid accumulation and stress tolerance genes expression

    PubMed Central

    Tan, Qian-Qian; Liu, Wen; Zhu, Fen; Lei, Chao-Liang; Wang, Xiao-Ping

    2017-01-01

    Diapause, also known as dormancy, is a state of arrested development that allows insects to survive unfavorable environmental conditions. Diapause-destined insects store large amounts of fat when preparing for diapause. However, the extent to which these accumulated fat reserves influence diapause remains unclear. To address this question, we investigated the function of fatty acid synthase (FAS), which plays a central role in lipid synthesis, in stress tolerance, the duration of diapause preparation, and whether insects enter diapause or not. In diapause-destined adult female cabbage beetles, Colaphellus bowringi, FAS2 was more highly expressed than FAS1 at the peak stage of diapause preparation. FAS2 knockdown suppressed lipid accumulation and subsequently affected stress tolerance genes expression and water content. However, silencing FAS2 had no significant effects on the duration of diapause preparation or the incidence of diapause. FAS2 transcription was suppressed by juvenile hormone (JH) and the JH receptor methoprene-tolerant (Met). These results suggest that the absence of JH-Met induces FAS2 expression, thereby promoting lipid storage in diapause-destined female beetles. These results demonstrate that fat reserves regulate stress tolerance genes expression and water content, but have no significant effect on the duration of diapause preparation or the incidence of diapause. PMID:28071706

  12. Ascorbic Acid Enhances the Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in Roots of Tall Fescue (Festuca arundinacea Schreb.)

    PubMed Central

    Gao, Yanzheng; Li, Hui; Gong, Shuaishuai

    2012-01-01

    Plant contamination by polycyclic aromatic hydrocarbons (PAHs) is crucial to food safety and human health. Enzyme inhibitors are commonly utilized in agriculture to control plant metabolism of organic components. This study revealed that the enzyme inhibitor ascorbic acid (AA) significantly reduced the activities of peroxidase (POD) and polyphenol oxidase (PPO), thus enhancing the potential risks of PAH contamination in tall fescue (Festuca arundinacea Schreb.). POD and PPO enzymes in vitro effectively decomposed naphthalene (NAP), phenanthrene (PHE) and anthracene (ANT). The presence of AA reduced POD and PPO activities in plants, and thus was likely responsible for enhanced PAH accumulation in tall fescue. This conclusion is supported by the significantly enhanced uptake of PHE in plants in the presence of AA, and the positive correlation between enzyme inhibition efficiencies and the rates of metabolism of PHE in tall fescue roots. This study provides a new perspective, that the common application of enzyme inhibitors in agricultural production could increase the accumulation of organic contaminants in plants, hence enhancing risks to food safety and quality. PMID:23185628

  13. Environmental Nitrate Stimulates Abscisic Acid Accumulation in Arabidopsis Root Tips by Releasing It from Inactive Stores[OPEN

    PubMed Central

    2016-01-01

    Abscisic acid (ABA) signaling plays a major role in root system development, regulating growth and root architecture. However, the precise localization of ABA remains undetermined. Here, we present a mechanism in which nitrate signaling stimulates the release of bioactive ABA from the inactive storage form, ABA-glucose ester (ABA-GE). We found that ABA accumulated in the endodermis and quiescent center of Arabidopsis thaliana root tips, mimicking the pattern of SCARECROW expression, and (to lower levels) in the vascular cylinder. Nitrate treatment increased ABA levels in root tips; this stimulation requires the activity of the endoplasmic reticulum-localized, ABA-GE-deconjugating enzyme β-GLUCOSIDASE1, but not de novo ABA biosynthesis. Immunogold labeling demonstrated that ABA is associated with cytoplasmic structures near, but not within, the endoplasmic reticulum. These findings demonstrate a mechanism for nitrate-regulated root growth via regulation of ABA accumulation in the root tip, providing insight into the environmental regulation of root growth. PMID:26887919

  14. Sulfur alleviates arsenic toxicity by reducing its accumulation and modulating proteome, amino acids and thiol metabolism in rice leaves

    PubMed Central

    Dixit, Garima; Singh, Amit Pal; Kumar, Amit; Dwivedi, Sanjay; Deeba, Farah; Kumar, Smita; Suman, Shankar; Adhikari, Bijan; Shukla, Yogeshwar; Trivedi, Prabodh Kumar; Pandey, Vivek; Tripathi, Rudra Deo

    2015-01-01

    Arsenic (As) contamination of water is a global concern and rice consumption is the biggest dietary exposure to human posing carcinogenic risks, predominantly in Asia. Sulfur (S) is involved in di-sulfide linkage in many proteins and plays crucial role in As detoxification. Present study explores role of variable S supply on rice leaf proteome, its inclination towards amino acids (AA) profile and non protein thiols under arsenite exposure. Analysis of 282 detected proteins on 2-DE gel revealed 113 differentially expressed proteins, out of which 80 were identified by MALDI-TOF-TOF. The identified proteins were mostly involved in glycolysis, TCA cycle, AA biosynthesis, photosynthesis, protein metabolism, stress and energy metabolism. Among these, glycolytic enzymes play a major role in AA biosynthesis that leads to change in AAs profiling. Proteins of glycolytic pathway, photosynthesis and energy metabolism were also validated by western blot analysis. Conclusively S supplementation reduced the As accumulation in shoot positively skewed thiol metabolism and glycolysis towards AA accumulation under AsIII stress. PMID:26552588

  15. Sulfur alleviates arsenic toxicity by reducing its accumulation and modulating proteome, amino acids and thiol metabolism in rice leaves

    NASA Astrophysics Data System (ADS)

    Dixit, Garima; Singh, Amit Pal; Kumar, Amit; Dwivedi, Sanjay; Deeba, Farah; Kumar, Smita; Suman, Shankar; Adhikari, Bijan; Shukla, Yogeshwar; Trivedi, Prabodh Kumar; Pandey, Vivek; Tripathi, Rudra Deo

    2015-11-01

    Arsenic (As) contamination of water is a global concern and rice consumption is the biggest dietary exposure to human posing carcinogenic risks, predominantly in Asia. Sulfur (S) is involved in di-sulfide linkage in many proteins and plays crucial role in As detoxification. Present study explores role of variable S supply on rice leaf proteome, its inclination towards amino acids (AA) profile and non protein thiols under arsenite exposure. Analysis of 282 detected proteins on 2-DE gel revealed 113 differentially expressed proteins, out of which 80 were identified by MALDI-TOF-TOF. The identified proteins were mostly involved in glycolysis, TCA cycle, AA biosynthesis, photosynthesis, protein metabolism, stress and energy metabolism. Among these, glycolytic enzymes play a major role in AA biosynthesis that leads to change in AAs profiling. Proteins of glycolytic pathway, photosynthesis and energy metabolism were also validated by western blot analysis. Conclusively S supplementation reduced the As accumulation in shoot positively skewed thiol metabolism and glycolysis towards AA accumulation under AsIII stress.

  16. Control of Diapause by Acidic pH and Ammonium Accumulation in the Hemolymph of Antarctic Copepods

    PubMed Central

    Schründer, Sabine; Schnack-Schiel, Sigrid B.; Auel, Holger; Sartoris, Franz Josef

    2013-01-01

    Life-cycles of polar herbivorous copepods are characterised by seasonal/ontogenetic vertical migrations and diapause to survive periods of food shortage during the long winter season. However, the triggers of vertical migration and diapause are still far from being understood. In this study, we test the hypothesis that acidic pH and the accumulation of ammonium (NH4+) in the hemolymph contribute to the control of diapause in certain Antarctic copepod species. In a recent study, it was already hypothesized that the replacement of heavy ions by ammonium is necessary for diapausing copepods to achieve neutral buoyancy at overwintering depth. The current article extends the hypothesis of ammonium-aided buoyancy by highlighting recent findings of low pH values in the hemolymph of diapausing copepods with elevated ammonium concentrations. Since ammonia (NH3) is toxic to most organisms, a low hemolymph pH is required to maintain ammonium in the less toxic ionized form (NH4+). Recognizing that low pH values are a relevant factor reducing metabolic rate in other marine invertebrates, the low pH values found in overwintering copepods might not only be a precondition for ammonium accumulation, but in addition, it may insure metabolic depression throughout diapause. PMID:24143238

  17. Foliar Abscisic Acid-To-Ethylene Accumulation and Response Regulate Shoot Growth Sensitivity to Mild Drought in Wheat

    PubMed Central

    Valluru, Ravi; Davies, William J.; Reynolds, Matthew P.; Dodd, Ian C.

    2016-01-01

    Although, plant hormones play an important role in adjusting growth in response to environmental perturbation, the relative contributions of abscisic acid (ABA) and ethylene remain elusive. Using six spring wheat genotypes differing for stress tolerance, we show that young seedlings of the drought-tolerant (DT) group maintained or increased shoot dry weight (SDW) while the drought-susceptible (DS) group decreased SDW in response to mild drought. Both the DT and DS groups increased endogenous ABA and ethylene concentrations under mild drought compared to control. The DT and DS groups exhibited different SDW response trends, whereby the DS group decreased while the DT group increased SDW, to increased concentrations of ABA and ethylene under mild drought, although both groups decreased ABA/ethylene ratio under mild drought albeit at different levels. We concluded that SDW of the DT and DS groups might be distinctly regulated by specific ABA:ethylene ratio. Further, a foliar-spray of low concentrations (0.1 μM) of ABA increased shoot relative growth rate (RGR) in the DS group while ACC (1-aminocyclopropane-1-carboxylic acid, ethylene precursor) spray increased RGR in both groups compared to control. Furthermore, the DT group accumulated a significantly higher galactose while a significantly lower maltose in the shoot compared to the DS group. Taken all together, these results suggest an impact of ABA, ethylene, and ABA:ethylene ratio on SDW of wheat seedlings that may partly underlie a genotypic variability of different shoot growth sensitivities to drought among crop species under field conditions. We propose that phenotyping based on hormone accumulation, response and hormonal ratio would be a viable, rapid, and an early–stage selection tool aiding genotype selection for stress tolerance. PMID:27148292

  18. Accumulation of methyl-deficient rat liver messenger ribonucleic acid on ethionine administration

    SciTech Connect

    Goswami, B.B.; Sharma, O.K.

    1980-01-01

    Highly purified poly(adenylic acid)-containing RNA isolated from livers of rats fed 0.25% DL-etionine in the diet for 7 days accepted methyl groups from S-adenosyl(methyl-/sup 3/H)methionine, when incubated in vitro with mRNA methyltransferases from vaccinia virus or Ehrlich ascites cells, whereas RNA from control rats had no such activity. Nuclease digestion followed by chromatographic analyses of mRNA methylated in vitro revealed that the methyl groups were incorporated at the 5' end into cap 1 structures (m/sup 7/GpppNmp...) by the viral enzyme, whereas both cap 0 (m/sup 7/GpppNp...) and cap 1 (m/sup 7/Gpppm/sup 6/Am...) structures were formed by the Ehrlich ascites cell enzymes. the methyl-deficient mRNA isolated from the liver of ethionine-fed rats differed in its translational properties from mRNA isolated from control animals in an in vitro protein synthesizing system from wheat germ.

  19. Accumulating Evidence Supports a Taste Component for Free Fatty Acids in Humans

    PubMed Central

    Mattes, Richard D.

    2011-01-01

    The requisite criteria for what constitutes a taste primary have not been established. Recent advances in understanding of the mechanisms and functions of taste have prompted suggestions for an expanded list of unique taste sensations, including fat, or more specifically, free fatty acids (FFA). A set of criteria are proposed here and the data related to FFA are reviewed on each point. It is concluded that the data are moderate to strong that there are: A) adaptive advantages to FFA detection in the oral cavity; B) adequate concentrations of FFA to serve as taste stimuli; C) multiple complimentary putative FFA receptors on taste cells; D) signals generated by FFA that are conveyed by gustatory nerves; E) sensations generated by FFA that can be detected and scaled by psychophysical methods in humans when non-gustatory cues are masked; and F) physiological responses to oral fat/FFA exposure. On no point is there strong evidence challenging these observations. The reviewed findings are suggestive, albeit not definitive, that there is a taste component for FFA. PMID:21557960

  20. Root jasmonic acid synthesis and perception regulate folivore-induced shoot metabolites and increase Nicotiana attenuata resistance.

    PubMed

    Fragoso, Variluska; Rothe, Eva; Baldwin, Ian T; Kim, Sang-Gyu

    2014-06-01

    While jasmonic acid (JA) signaling is widely accepted as mediating plant resistance to herbivores, and the importance of the roots in plant defenses is recently being recognized, the role of root JA in the defense of above-ground parts remains unstudied. To restrict JA impairment to the roots, we micrografted wildtype Nicotiana attenuata shoots to the roots of transgenic plants impaired in JA signaling and evaluated ecologically relevant traits in the glasshouse and in nature. Root JA synthesis and perception are involved in regulating nicotine production in roots. Strikingly, systemic root JA regulated local leaf JA and abscisic acid (ABA) concentrations, which were associated with differences in nicotine transport from roots to leaves via the transpiration stream. Root JA signaling also regulated the accumulation of other shoot metabolites; together these account for differences in resistance against a generalist, Spodoptera littoralis, and a specialist herbivore, Manduca sexta. In N. attenuata's native habitat, silencing root JA synthesis increased the shoot damage inflicted by Empoasca leafhoppers, which are able to select natural jasmonate mutants. Silencing JA perception in roots also increased damage by Tupiocoris notatus. We conclude that attack from above-ground herbivores recruits root JA signaling to launch the full complement of plant defense responses.

  1. Saxitoxins and okadaic acid group: accumulation and distribution in invertebrate marine vectors from Southern Chile.

    PubMed

    García, Carlos; Pérez, Francisco; Contreras, Cristóbal; Figueroa, Diego; Barriga, Andrés; López-Rivera, Américo; Araneda, Oscar F; Contreras, Héctor R

    2015-01-01

    Harmful algae blooms (HABs) are the main source of marine toxins in the aquatic environment surrounding the austral fjords in Chile. Huichas Island (Aysén) has an history of HABs spanning more than 30 years, but there is limited investigation of the bioaccumulation of marine toxins in the bivalves and gastropods from the Region of Aysén. In this study, bivalves (Mytilus chilenses, Choromytilus chorus, Aulacomya ater, Gari solida, Tagelus dombeii and Venus antiqua) and carnivorous gastropods (Argobuccinum ranelliformes and Concholepas concholepas) were collected from 28 sites. Researchers analysed the accumulation of STX-group toxins using a LC with a derivatisation post column (LC-PCOX), while lipophilic toxins (OA-group, azapiracids, pectenotoxins and yessotoxins) were analysed using LC-MS/MS with electrospray ionisation (+/-) in visceral (hepatopancreas) and non-visceral tissues (mantle, adductor muscle, gills and foot). Levels of STX-group and OA-group toxins varied among individuals from the same site. Among all tissue samples, the highest concentrations of STX-group toxins were noted in the hepatopancreas in V. antiqua (95 ± 0.1 μg STX-eq 100 g(-1)), T. dombeii (148 ± 1.4 μg STX-eq 100 g(-1)) and G. solida (3232 ± 5.2 μg STX-eq 100 g(-1); p < 0.05); in the adductor muscle in M. chilensis (2495 ± 6.4 μg STX-eq 100 g(-1); p < 0.05) and in the foot in C. concholepas (81 ± 0.7 μg STX-eq 100 g(-1)) and T. dombeii (114 ± 1.2 μg STX-eq 100 g(-1)). The highest variability of toxins was detected in G. solida, where high levels of carbamate derivatives were identified (GTXs, neoSTX and STX). In addition to the detected hydrophilic toxins, OA-group toxins were detected (OA and DTX-1) with an average ratio of ≈1:1. The highest levels of OA-group toxins were in the foot of C. concholepas, with levels of 400.3 ± 3.6 μg OA eq kg(-1) (p < 0.05) and with a toxic profile composed of 90% OA. A wide range of OA-group toxins was detected in M. chilensis with a

  2. pH Titratable Superparamagnetic Iron Oxide for Improved Nanoparticle Accumulation in Acidic Tumor Microenvironments

    PubMed Central

    Crayton, Samuel H.; Tsourkas, Andrew

    2011-01-01

    A wide variety of nanoparticle platforms are being developed for the diagnosis and treatment of malignancy. While many of these are passively targeted or rely on receptor-ligand interactions, metabolically directed nanoparticles provide a complementary approach. It is known that both primary and secondary events in tumorigensis alter the metabolic profile of developing and metastatic cancers. One highly conserved metabolic phenotype is a state of up-regulated glycolysis and reduced use of oxidative phosphorylation, even when oxygen tension is not limiting. This metabolic shift, termed the Warburg effect, creates a “hostile” tumor microenvironment with increased levels of lactic acid and low extracellular pH. In order to exploit this phenomenon and improve the delivery of nanoparticle platforms to a wide variety of tumors, a pH-responsive iron oxide nanoparticle was designed. Specifically, glycol chitosan (GC), a water-soluble polymer with pH titratable charge, was conjugated to the surface of superparamagnetic iron oxide nanoparticles (SPIO) to generate a T2*-weighted MR contrast agent that responds to alterations in its surrounding pH. Compared to control nanoparticles that lack pH sensitivity, these GC-SPIO nanoparticles demonstrated potent pH-dependent cellular association and MR contrast in vitro. In murine tumor models GC-SPIO also generated robust T2*-weighted contrast, which correlated with increased delivery of the agent to the tumor site, measured quantitatively by inductively coupled plasma mass spectrometry. Importantly, the increased delivery of GC-SPIO nanoparticles cannot be solely attributed to the commonly observed enhanced permeability and retention effect, since these nanoparticles have similar physical properties and blood circulation times as control agents. PMID:22035454

  3. Induction of a reversible cardiac lipidosis by a dietary long-chain fatty acid (erucic acid). Relationship to lipid accumulation in border zones of myocardial infarcts.

    PubMed Central

    Chien, K. R.; Bellary, A.; Nicar, M.; Mukherjee, A.; Buja, L. M.

    1983-01-01

    Previous studies have demonstrated that cardiac myocytes in the border zone of acute myocardial infarction become markedly overloaded with neutral lipid during the transition from reversible to irreversible injury. To examine directly the role of these changes in neutral lipid metabolism in the development of irreversible cellular injury and associated increases in tissue Ca2+ content, the authors fed rats large amounts of a fatty acid (erucic acid) that is poorly oxidized by the heart and that subsequently accumulates as neutral lipid. Rats fed a high erucic acid (C22:1) diet in the form of 20% rapeseed oil for 3-5 days had a fourfold increase in triglyceride (49.5 +/- 3.8 SEM mg/g wet wt versus 13.6 +/- 13, n = 4) and a 60% increase in long-chain acyl CoA content (166.0 +/- 21.9 versus 91.5 +/- 9.0 nM/g wet wt, n = 4), compared with controls. However, there was no change in long-chain acyl carnitine or total phospholipid content. Histochemical studies showed accumulation of numerous lipid droplets in the myocytes, and electron microscopy revealed localization of lipid vesicles in direct contact with mitochondria, thus mimicking the lipid-laden cells in the border zone regions of acute myocardial infarcts. The acute lipidosis was reversible with either continued feeding of erucic acid for several weeks or conversion to a normal diet. It was not associated with an increased tissue Ca2+ content, nor with cell necrosis. However, continued erucic acid intake for 3 months was associated with focal myocardial degeneration and loss of myocytes. These results suggest that acute increases in neutral lipids, as found in the border zone of acute myocardial infarction, may not be the cause of progression to irreversible damage during acute myocardial injury, but that the persistent presence of similar lipid material over months may result in focal myocardial degeneration. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:6859230

  4. Toxic synergism between quinolinic acid and organic acids accumulating in glutaric acidemia type I and in disorders of propionate metabolism in rat brain synaptosomes: Relevance for metabolic acidemias.

    PubMed

    Colín-González, A L; Paz-Loyola, A L; Serratos, I; Seminotti, B; Ribeiro, C A J; Leipnitz, G; Souza, D O; Wajner, M; Santamaría, A

    2015-11-12

    The brain of children affected by organic acidemias develop acute neurodegeneration linked to accumulation of endogenous toxic metabolites like glutaric (GA), 3-hydroxyglutaric (3-OHGA), methylmalonic (MMA) and propionic (PA) acids. Excitotoxic and oxidative events are involved in the toxic patterns elicited by these organic acids, although their single actions cannot explain the extent of brain damage observed in organic acidemias. The characterization of co-adjuvant factors involved in the magnification of early toxic processes evoked by these metabolites is essential to infer their actions in the human brain. Alterations in the kynurenine pathway (KP) - a metabolic route devoted to degrade tryptophan to form NAD(+) - produce increased levels of the excitotoxic metabolite quinolinic acid (QUIN), which has been involved in neurodegenerative disorders. Herein we investigated the effects of subtoxic concentrations of GA, 3-OHGA, MMA and PA, either alone or in combination with QUIN, on early toxic endpoints in rat brain synaptosomes. To establish specific mechanisms, we pre-incubated synaptosomes with different protective agents, including the endogenous N-methyl-d-aspartate (NMDA) receptor antagonist kynurenic acid (KA), the antioxidant S-allylcysteine (SAC) and the nitric oxide synthase (NOS) inhibitor nitro-l-arginine methyl ester (l-NAME). While the incubation of synaptosomes with toxic metabolites at subtoxic concentrations produced no effects, their co-incubation (QUIN+GA, +3-OHGA, +MMA or +PA) decreased the mitochondrial function and increased reactive oxygen species (ROS) formation and lipid peroxidation. For all cases, this effect was partially prevented by KA and l-NAME, and completely avoided by SAC. These findings suggest that early damaging events elicited by organic acids involved in metabolic acidemias can be magnified by toxic synergism with QUIN, and this process is mostly mediated by oxidative stress, and in a lesser extent by excitotoxicity and

  5. Responses in growth, lipid accumulation, and fatty acid composition of four oleaginous microalgae to different nitrogen sources and concentrations

    NASA Astrophysics Data System (ADS)

    Li, Tao; Wan, Linglin; Li, Aifen; Zhang, Chengwu

    2013-11-01

    Nitrogen deficiency is an effective strategy for enhancing lipid production in microalgae. Close relationships exist among lipid production, microalgal species, and nitrogen sources. We report growth, lipid accumulation, and fatty acid composition in four microalgae ( Chlorococcum ellipsoideum UTEX972, Chlorococcum nivale LB2225, Chlorococcum tatrense UTEX2227, and Scenedesmus deserticola JNU19) under nitrate- and urea-nitrogen deficiencies. We found three patterns of response to nitrogen deficiency: Type-A (decrease in biomass and increase in lipid content), Type-B (reduction in both biomass and lipid content), and Type-C (enhancement of both biomass and lipid content). Type-C microalgae are potential candidates for large-scale oil production. Chlorococcum ellipsoideum, for example, exhibited a neutral lipid production of up to 239.6 mg/(L·d) under urea-nitrogen deficiency. In addition, nitrogen deficiency showed only a slight influence on lipid fractions and fatty acid composition. Our study provides useful information for further screening hyper-lipid microalgal strains for biofuel production.

  6. Topical application of 5-aminolevulinic acid, DMSO and EDTA: protoporphyrin IX accumulation in skin and tumours of mice.

    PubMed

    Malik, Z; Kostenich, G; Roitman, L; Ehrenberg, B; Orenstein, A

    1995-06-01

    Topical 5-aminolevulinic acid (ALA) application in three different creams was carried out on mice bearing subcutaneously transplanted C26 colon carcinoma. The creams contained (a) 20% ALA alone, (b) ALA with 2% dimethylsulphoxide (DMSO) and (c) ALA, DMSO and 2% edetic acid disodium salt (EDTA). Protoporphyrin IX (PP) production in the tumour and in the skin overlying the tumour was studied by two methods: laser-induced fluorescence (LIF) and chemical extraction. The kinetics of PP production in the skin and in the tumour, as studied by the LIF method, was similar for all three cream preparations. The PP fluorescence intensity in the tissues reached its maximum 4-6 h after application of the creams. Quantitative analysis showed that the PP concentration after treatment was more pronounced in the skin than in the tumour. The efficiency of porphyrin production in the skin by the creams used was in the following order: ALA-DMSO-EDTA > ALA-DMSO > ALA. In the tumour the enhancing effect of DMSO and EDTA on PP accumulation induced by ALA was observed mainly in the upper 2 mm section. However, the concentration of PP in the tumour was found to be approximately the same for ALA-DMSO and ALA-DMSO-EDTA cream combinations. The possible mechanisms of the effect of DMSO and EDTA are discussed.

  7. Enhancing the accumulation of omega-3 long chain polyunsaturated fatty acids in transgenic Arabidopsis thaliana via iterative metabolic engineering and genetic crossing.

    PubMed

    Ruiz-López, Noemi; Haslam, Richard P; Venegas-Calerón, Mónica; Li, Tianbi; Bauer, Joerg; Napier, Johnathan A; Sayanova, Olga

    2012-12-01

    The synthesis and accumulation of long chain polyunsaturated fatty acids such as eicosapentaenoic acid has previously been demonstrated in the seeds of transgenic plants. However, the obtained levels are relatively low, indicating the need for further studies and the better definition of the interplay between endogenous lipid synthesis and the non-native transgene-encoded activities. In this study we have systematically compared three different transgenic configurations of the biosynthetic pathway for eicosapentaenoic acid, using lipidomic profiling to identify metabolic bottlenecks. We have also used genetic crossing to stack up to ten transgenes in Arabidopsis. These studies indicate several potential approaches to optimize the accumulation of target fatty acids in transgenic plants. Our data show the unexpected channeling of heterologous C20 polyunsaturated fatty acids into minor phospholipid species, and also the apparent negative metabolic regulation of phospholipid-dependent Δ6-desaturases. Collectively, this study confirms the benefits of iterative approaches to metabolic engineering of plant lipid synthesis.

  8. An Intronless β-amyrin Synthase Gene is More Efficient in Oleanolic Acid Accumulation than its Paralog in Gentiana straminea

    PubMed Central

    Liu, Yanling; Zhao, Zhongjuan; Xue, Zheyong; Wang, Long; Cai, Yunfei; Wang, Peng; Wei, Tiandi; Gong, Jing; Liu, Zhenhua; Li, Juan; Li, Shuo; Xiang, Fengning

    2016-01-01

    Paralogous members of the oxidosqualene cyclase (OSC) family encode a diversity of enzymes that are important in triterpenoid biosynthesis. This report describes the isolation of the Gentiana straminea gene GsAS2 that encodes a β-amyrin synthase (βAS) enzyme. Unlike its previously isolated paralog GsAS1, GsAS2 lacks introns. Its predicted protein product was is a 759 residue polypeptide that shares high homology with other known β-amyrin synthases (βASs). Heterologously expressed GsAS2 generates more β-amyrin in yeast than does GsAS1. Constitutive over-expression of GsAS2 resulted in a 5.7 fold increase in oleanolic acid accumulation, while over-expression of GsAS1 led to a 3 fold increase. Additionally, RNAi-directed suppression of GsAS2 and GsAS1 in G. straminea decreased oleonolic acid levels by 65.9% and 21% respectively, indicating that GsAS2 plays a more important role than GsAS1 in oleanolic acid biosynthesis in G. straminea. We uses a docking model to explore the catalytic mechanism of GsAS1/2 and predicted that GsAS2, with its Y560, have higher efficiency than GsAS1 and mutated versions of GsAS2 in β-amyrin produce. When the key residue in GsAS2 was mutagenized, it produced about 41.29% and 71.15% less β-amyrin than native, while the key residue in GsAS1 was mutagenized to that in GsAS2, the mutant produced 38.02% more β-amyrin than native GsAS1. PMID:27624821

  9. The Unusual Acid-Accumulating Behavior during Ripening of Cherimoya (Annona cherimola Mill.) is Linked to Changes in Transcription and Enzyme Activity Related to Citric and Malic Acid Metabolism.

    PubMed

    González-Agüero, Mauricio; Tejerina Pardo, Luis; Zamudio, María Sofía; Contreras, Carolina; Undurraga, Pedro; Defilippi, Bruno G

    2016-04-25

    Cherimoya (Annona cherimola Mill.) is a subtropical fruit characterized by a significant increase in organic acid levels during ripening, making it an interesting model for studying the relationship between acidity and fruit flavor. In this work, we focused on understanding the balance between the concentration of organic acids and the gene expression and activity of enzymes involved in the synthesis and degradation of these metabolites during the development and ripening of cherimoya cv. "Concha Lisa". Our results showed an early accumulation of citric acid and other changes associated with the accumulation of transcripts encoding citrate catabolism enzymes. During ripening, a 2-fold increase in malic acid and a 6-fold increase in citric acid were detected. By comparing the contents of these compounds with gene expression and enzymatic activity levels, we determined that cytoplasmic NAD-dependent malate dehydrogenase (cyNAD-MDH) and mitochondrial citrate synthase (mCS) play important regulatory roles in the malic and citric acid biosynthetic pathways.

  10. l-Ascorbic Acid Is Accumulated in Source Leaf Phloem and Transported to Sink Tissues in Plants1

    PubMed Central

    Franceschi, Vincent R.; Tarlyn, Nathan M.

    2002-01-01

    l-Ascorbic acid (AsA) was found to be loaded into phloem of source leaves and transported to sink tissues. When l-[14C]AsA was applied to leaves of intact plants of three different species, autoradiographs and HPLC analysis demonstrated that AsA was accumulated into phloem and transported to root tips, shoots, and floral organs, but not to mature leaves. AsA was also directly detected in Arabidopsis sieve tube sap collected from an English green aphid (Sitobion avenae) stylet. Feeding a single leaf of intact Arabidopsis or Medicago sativa with 10 or 20 mm l-galactono-1,4-lactone (GAL-l), the immediate precursor of AsA, lead to a 7- to 8-fold increase in AsA in the treated leaf and a 2- to 3-fold increase of AsA in untreated sink tissues of the same plant. The amount of AsA produced in treated leaves and accumulated in sink tissues was proportional to the amount of GAL-l applied. Studies of the ability of organs to produce AsA from GAL-l showed mature leaves have a 3- to 10-fold higher biosynthetic capacity and much lower AsA turnover rate than sink tissues. The results indicate AsA transporters reside in the phloem, and that AsA translocation is likely required to meet AsA demands of rapidly growing non-photosynthetic tissues. This study also demonstrates that source leaf AsA biosynthesis is limited by substrate availability rather than biosynthetic capacity, and sink AsA levels may be limited to some extent by source production. Phloem translocation of AsA may be one factor regulating sink development because AsA is critical to cell division/growth. PMID:12376632

  11. Endogenous salicylic acid levels correlate with accumulation of pathogenesis-related proteins and virus resistance in tobacco

    SciTech Connect

    Yalpani, N.; Shulaev, V.; Raskin, I. )

    1993-07-01

    Salicylic acid (SA) is hypothesized to be an endogenous regulator of local and systemic disease resistance and an inducer of pathogenesis-related (PR) proteins among plants. High levels of PR proteins have been observed in an uninoculated amphidiploid hybrid of Nicotiana glutinosa [times] N. debneyi, which is highly resistant to tobacco mosaic virus (TMV). Fluoresence, UV, and mass spectral analysis established that the levels of SA in healthy N. glutinosa [times] N. debneyi leaves were 30 times greater than in N. tabacum [open quotes]Xanthi-nc[close quotes] tobacco, which does not constitutively express PR proteins and is less resistant to TMV. Upon TMV-inoculation SA levels increased at least 70-fold leaves of Xanthi-nc but role only slightly in the hybrid. Phloem exudates of N. glutinosa [times] N. debneyi contained at least 500 times more SA than those of Xanthi-nc. SA treatment caused the appearance of PR-1 protein in Xanthi-nc but did not affect constitutively high levels of PR-1 protein in N. glutinosa [times] N. debneyi. In contrast to Xanthi-nc tobacco, TMV-inoculated N. glutinosa [times] N. debneyi kept at 32 C accumulated more than 0.5 [mu]g SA/g fresh weight, maintained high levels of PR proteins, and developed a hypersensitive response to TMV. PR proteins have previously been shown to accumulate in the lower leaves of healthy, flowering Xanthi-nc tobacco, which exhibited increased resistance to TMV. These developmentally induced increases in resistance and PR-1 proteins positively correlated with tissue levels of SA. These results affirm the regulatory role of SA in disease resistance and PR protein production. 31 refs., 9 figs., 1 tab.

  12. Identification of Jasmonic Acid and Jasmonoyl-Isoleucine, and Characterization of AOS, AOC, OPR and JAR1 in the Model Lycophyte Selaginella moellendorffii.

    PubMed

    Pratiwi, Putri; Tanaka, Genta; Takahashi, Tomohiro; Xie, Xiaonan; Yoneyama, Koichi; Matsuura, Hideyuki; Takahashi, Kosaku

    2017-03-13

    Jasmonic acid (JA) is involved in a variety of physiological responses in seed plants. However, the detection and role of JA in lycophytes, a group of seedless vascular plants, have remained elusive until recently. This study provides the first evidence of 12-oxo-phytodienoic acid (OPDA), JA and jasmonoyl-isoleucine (JA-Ile) in the model lycophyte Selaginella moellendorffii. Mechanical wounding stimulated the accumulation of OPDA, JA and JA-Ile. These data were corroborated by the detection of enzymatically active allene oxide synthase (AOS), allene oxide cyclase (AOC), 12-oxo-phytodienoic acid reductase 3 (OPR3) and JA-Ile synthase (JAR1) in S. moellendorffii. SmAOS2 is involved in the first committed step of JA biosynthesis. SmAOC1 is a crucial enzyme for generating the basic structure of jasmonates and is actively involved in the formation of OPDA. SmOPR5, a functionally active OPR3-like enzyme, is also vital for the reduction of (+)-cis-OPDA, the only isomer of the JA precursor. The conjugation of JA to Ile by SmJAR1 demonstrates that S. moellendorffii produces JA-Ile. Thus, the four active enzymes have characteristics similar to those in seed plants. Wounding and JA treatment induced the expression of SmAOC1 and SmOPR5. Furthermore, JA inhibited the growth of shoots in S. moellendorffii, which suggests that JA functions as a signaling molecule in S. moellendorffii. This study proposes that JA evolved as a plant hormone for stress adaptation, beginning with the emergence of vascular plants.

  13. Jasmonic and salicylic acids enhanced phytochemical production and biological activities in cell suspension cultures of spine gourd (Momordica dioica Roxb).

    PubMed

    Chung, Ill-Min; Rekha, Kaliyaperumal; Rajakumar, Govindasamy; Thiruvengadam, Muthu

    2017-03-01

    In vitro cell suspension culture was established for the production of commercially valuable phytochemicals in Momordica dioica. The influence of elicitors in jasmonic acid (JA) and salicylic acid (SA) increased their effect on phytochemical production and biomass accumulation in M. dioica. The results indicate that compared with non-elicited cultures, JA- and SA-elicited cell suspension cultures had significantly enhanced phenolic, flavonoid, and carotenoid production, as well as antioxidant, antimicrobial, and antiproliferative activities. Furthermore, elicited cultures produced 22 phenolic compounds, such as flavonols, hydroxycinnamic acids, and hydroxybenzoic acids. Greater biomass production, phytochemical accumulation, and biological activity occurred in JA- than in SA-elicited cell cultures. This study is the first to successfully establish M. dioica cell suspension cultures for the production of phenolic compounds and carotenoids, as well as for biomass accumulation.

  14. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  15. Specific accumulation of GFP in a non-acidic vacuolar compartment via a C-terminal propeptide-mediated sorting pathway.

    PubMed

    Di Sansebastiano, G P; Paris, N; Marc-Martin, S; Neuhaus, J M

    1998-08-01

    The green fluorescent protein (GFP) from Aequorea victoria can be detected in living plant cells after transient transformation of protoplasts. Expression of the GFP can be used to monitor protein trafficking in a mixed cell population and also to study the different function and importance of organelles in different cell types. We developed a vacuolar form of GFP that was obtained by replacing the C-terminal endoplasmic reticulum (ER)-retention motif of mGFP5-ER by the vacuolar targeting peptide of tobacco chitinase A. The vacuolar GFP was transported and accumulated in the vacuole as expected. However, we found two patterns of GFP accumulation after prolonged incubation (18-24 h) depending on the cell type. Most chloroplast-rich protoplasts had a fluorescent large central vacuole. In contrast, most chloroplast-poor protoplasts accumulated the GFP in one smaller vacuole but not in the large central vacuole, which was visible under a light microscope in the same cell. This differential accumulation reflected the existence of two different vacuolar compartments as described recently by immunolocalization of several vacuolar markers. We were able to characterize the vacuolar compartment to which GFP is specifically targeted as non-acidic, since it did not accumulate neutral red while acidic vacuoles did not accumulate GFP.

  16. Weak effect of trans-10, cis-12-conjugated linoleic acid on body fat accumulation in adult hamsters.

    PubMed

    Miranda, Jonatan; Churruca, Itziar; Fernández-Quintela, Alfredo; Rodríguez, Victor Manuel; Macarulla, María Teresa; Simón, Edurne; Portillo, María Puy

    2009-12-01

    It has been proposed that young animals and subjects are more responsive to conjugated linoleic acid (CLA) than the adults. Nevertheless, there is very little information concerning the effectiveness of CLA in adult animals. In the present study we aimed to explore the effects of trans-10, cis-12-CLA on body fat accumulation in adult hamsters, as well as on some of the molecular mechanisms described in young animals as responsible for the CLA body fat-lowering effect, such as lipogenesis, lipoprotein lipase (LPL)-mediated fat uptake and thermogenesis. The experiment was conducted with sixteen adult male Syrian Golden hamsters (aged 8 months) fed a high-fat diet supplemented or not with 0.5 % trans-10, cis-12-CLA for 6 weeks. Acetyl-CoA carboxylase (ACX), fatty acid synthase (FAS), LPL, PPARgamma, sterol regulatory element-binding protein (SREBP)-1a and SREBP-1c expressions were assessed in subcutaneous and perirenal adipose tissues by real-time RT-PCR. Total and heparin-releasable LPL activities were determined in subcutaneous adipose tissue by fluorimetry and FAS activity by spectrophotometry. Uncoupling protein-1 (UCP1) expression in interscapular brown adipose tissue was assessed by Western blot. Hamsters fed the trans-10, cis-12-CLA diet showed a significant reduction in subcutaneous adipose tissue. No changes were observed in the expression of ACX, FAS, LPL, SREBP-1a, SREBP-1c and PPARgamma, nor in total and heparin-releasable LPL and FAS activities. Trans-10, cis-12-CLA induced a significant increase in the amount of UCP1. These results suggest a low responsiveness to trans-10, cis-12-CLA in adults, lower than that in young hamsters. One of the reasons explaining this difference is the lack of effect on LPL.

  17. Estradiol enhances effects of fructose rich diet on cardiac fatty acid transporter CD36 and triglycerides accumulation.

    PubMed

    Korićanac, Goran; Tepavčević, Snežana; Romić, Snježana; Živković, Maja; Stojiljković, Mojca; Milosavljević, Tijana; Stanković, Aleksandra; Petković, Marijana; Kamčeva, Tina; Žakula, Zorica

    2012-11-05

    Fructose rich diet increases hepatic triglycerides production and has deleterious cardiac effects. Estrogens are involved in regulation of lipid metabolism as well, but their effects are cardio beneficial. In order to study effects of fructose rich diet on the main heart fatty acid transporter CD36 and the role of estrogens, we subjected ovariectomized female rats to the standard diet or fructose rich diet, with or without estradiol (E2) replacement. The following parameters were analyzed: feeding behavior, visceral adipose tissue mass, plasma lipids, cardiac CD36 expression, localization and insulin regulation, as well as the profile of cardiac lipids. Results show that fructose rich diet significantly increased plasma triglycerides and decreased plasma free fatty acid (FFA) concentration, while E2 additionally emphasized FFA decrease. The fructose diet increased cardiac plasma membrane content of CD36 in the basal and insulin-stimulated states, and decreased its low density microsomes content. The E2 in fructose-fed rats raised the total cardiac protein content of CD36, its presence in plasma membranes and low density microsomes, and cardiac deposition of triglycerides, as well. Although E2 counteracts fructose in some aspects of lipid metabolism, and separately they have opposite cardiac effects, in combination with fructose rich diet, E2 additionally enhances CD36 presence in plasma membranes of cardiac cells and triglycerides accumulation, which paradoxically might promote deleterious effects of fructose diet on cardiac lipid metabolism. Taken together, the results presented in this work are of high importance for clinical administration of estrogens in females with a history of type 2 diabetes.

  18. Sugar and organic acid accumulation in guard cells of Vicia faba in response to red and blue light

    SciTech Connect

    Talbott, L.D.; Zeiger, E. )

    1993-08-01

    Changes in neutral sugar and organic acid content of guard cells were quantitated by high-performance liquid chromatography during stomatal opening in different light qualities. Sonicated Vicia faba epidermal peels were irradiated with 10 [mu]mol m[sup [minus]2] s[sup [minus]1] of blue light, a fluence rate insufficient for the activation of guard cell photosynthesis, or 125 [mu]mol m[sup [minus]2] s[sup [minus]1] of red light, in the presence of 1mM KCl, 0.1 mM CaCl[sub 2]. The low-fluence-rate blue light stimulated an average net stomatal opening of 4.7 [mu]m in 2 h, whereas the saturating fluence rate of red light stimulated an average net opening of 3.8 [mu]m in 2 h. Under blue light, the malate content of guard cells increased to 173% of the initial level during the first 30 min of opening and declined as opening continued. Sucrose levels continuously rose throughout the blue light-stimulated opening, reaching 215% of the initial level after 2 h. The starch hydrolysis products maltose and maltotriose remained elevated at all times. Under red light, guard cells showed very little increase in organic acid or maltose levels, whereas sucrose levels increased to 208% of the initial level after 2 h. Total measured organic metabolite concentrations were correlated with stomatal apertures in all cases except where substantial malate increases occurred. These results support the hypothesis that light quality modulates alternative mechanisms of osmotic accumulation guard cells, including potassium uptake, photosynthetic sugar production, and starch breakdown. 29 refs., 5 figs., 2 tab.

  19. Accumulated metabolites of hydroxybutyric acid serve as diagnostic and prognostic biomarkers of ovarian high-grade serous carcinomas

    PubMed Central

    Hilvo, Mika; de Santiago, Ines; Gopalacharyulu, Peddinti; Schmitt, Wolfgang D.; Budczies, Jan; Kuhberg, Marc; Dietel, Manfred; Aittokallio, Tero; Markowetz, Florian; Denkert, Carsten; Sehouli, Jalid; Frezza, Christian

    2016-01-01

    Ovarian cancer is a heterogeneous disease of low prevalence, but poor survival. Early diagnosis is critical for survival, but is often challenging because the symptoms of ovarian cancer are subtle and become apparent only during advanced stages of the disease. Therefore, the identification of robust biomarkers of early disease is a clinical priority. Metabolomic profiling is an emerging diagnostic tool enabling the detection of biomarkers reflecting alterations in tumor metabolism, a hallmark of cancer. In this study, we performed metabolomic profiling of serum and tumor tissue from 158 patients with high-grade serous ovarian cancer (HGSOC) and 100 control patients with benign or non-neoplastic lesions. We report metabolites of hydroxybutyric acid (HBA) as novel diagnostic and prognostic biomarkers associated with tumor burden and patient survival. The accumulation of HBA metabolites caused by HGSOC was also associated with reduced expression of succinic semialdehyde dehydrogenase (encoded by ALDH5A1), and with the presence of an epithelial-to-mesenchymal transition (EMT) gene signature, implying a role for these metabolic alterations in cancer cell migration and invasion. In conclusion, our findings represent the first comprehensive metabolomics analysis in HGSOC and propose a new set of metabolites as biomarkers of disease with diagnostic and prognostic capabilities. PMID:26685161

  20. Induction of salicylic acid (SA) on transcriptional expression of eight carotenoid genes and astaxanthin accumulation in Haematococcus pluvialis.

    PubMed

    Gao, Zhengquan; Meng, Chunxiao; Zhang, Xiaowen; Xu, Dong; Miao, Xuexia; Wang, Yitao; Yang, Liming; Lv, Hongxin; Chen, Lingling; Ye, Naihao

    2012-09-10

    The green alga Haematococcus pluvialis can produce large amounts of pink carotenoid astaxanthin which is a high value ketocarotenoid. In our study, transcriptional expression patterns of eight carotenoid genes in H. pluvialis in response to SA were measured using qRT-PCR. Results indicated that both 25 and 50 mg/L salicylic acid (SA) could increase astaxanthin productivity and enhance transcriptional expression of eight carotenoid genes in H. pluvialis. But these genes exhibited different expression profiles. Moreover, SA25 (25 mg/L SA) induction had a greater effect on the transcriptional expression of ipi-1, psy, pds, crtR-B and lyc (more than 6-fold up-regulation) than on ipi-2, bkt and crtO, but SA50 (50 mg/L SA) treatment had a greater impact on the transcriptional expression of ipi-1, ipi-2, pds, crtR-B and lyc than on psy, bkt and crtO. Furthermore, astaxanthin biosynthesis under SA was up-regulated mainly by ipi-1, ipi-2, psy, crtR-B, bkt and crtO at transcriptional level, lyc at post-transcriptional level and pds at both levels. Summarily, these results suggest that SA constitute molecular signals in the network of astaxanthin biosynthesis. Induction of astaxanthin accumulation by SA without any other stimuli presents an attractive application potential in astaxanthin production with H. pluvialis.

  1. Control of. cap alpha. -amylase mRNA accumulation by gibberellic acid and calcium in barley aleurone layers

    SciTech Connect

    Deikman, J.; Jones, R.L.

    1985-01-01

    Pulse-labeling of barley (Hordeum vulgare L. cv Himalaya) aleurone layers incubated for 13 hours in 2.5 micromolar gibberellic acid (GA/sub 3/) with or without 5 millimolar CaCl/sub 2/ shows that ..cap alpha..-amylase isozymes 3 and 4 are not synthesized in vivo in the absence of Ca/sup 2 +/. No difference was observed in ..cap alpha..-amylase mRNA levels between layers incubated for 12 hours in 2.5 micromolar GA/sub 3/ with 5 millimolar CaCl/sub 2/ and layers incubated in GA/sub 3/ alone. RNA isolated from layers incubated for 12 hours in GA/sub 3/ with and without CA/sup 2 +/. A cDNA clone for ..cap alpha..-amylase was isolated and used to measure ..cap alpha..-amylase mRNA levels in aleurone layers incubated in the presence and absence of Ca/sup 2 +/ was translated in vitro and was found to produce the same complement of translation products regardless of the presence of Ca/sup 2 +/ in the incubation medium. Immunoprecipitation of translation products showed that the RNA for ..cap alpha..-amylase synthesized in Ca/sup 2 +/-deprived aleurone layers was translatable. Ca/sup 2 +/ is required for the synthesis of ..cap alpha..-amylase isozymes 3 and 4 at a step after mRNA accumulation and processing.

  2. Diets enriched in trans-11 vaccenic acid alleviate ectopic lipid accumulation in a rat model of NAFLD and metabolic syndrome.

    PubMed

    Jacome-Sosa, M Miriam; Borthwick, Faye; Mangat, Rabban; Uwiera, Richard; Reaney, Martin J; Shen, Jianheng; Quiroga, Ariel D; Jacobs, René L; Lehner, Richard; Proctor, Spencer D; Nelson, Randal C

    2014-07-01

    Trans11-18:1 (vaccenic acid, VA) is one of the most predominant naturally occurring trans fats in our food chain and has recently been shown to exert hypolipidemic effects in animal models. In this study, we reveal new mechanism(s) by which VA can alter body fat distribution, energy utilization and dysfunctional lipid metabolism in an animal model of obesity displaying features of the metabolic syndrome (MetS). Obese JCR:LA-cp rats were assigned to a control diet that included dairy-derived fat or the control diet supplemented with 1% VA. VA reduced total body fat (-6%), stimulated adipose tissue redistribution [reduced mesenteric fat (-17%) while increasing inguinal fat mass (29%)] and decreased adipocyte size (-44%) versus control rats. VA supplementation also increased metabolic rate (7%) concomitantly with an increased preference for whole-body glucose utilization for oxidation and increased insulin sensitivity [lower HOMA-IR (-59%)]. Further, VA decreased nonalcoholic fatty liver disease activity scores (-34%) and reduced hepatic (-27%) and intestinal (-39%) triglyceride secretion relative to control diet, while exerting differential transcriptional regulation of SREBP1 and FAS amongst other key genes in the liver and the intestine. Adding VA to dairy fat alleviates features of MetS potentially by remodeling adipose tissue and attenuating ectopic lipid accumulation in a rat model of obesity and MetS. Increasing VA content in the diet (naturally or by fortification) may be a useful approach to maximize the health value of dairy-derived fats.

  3. Mitigation effects of silicon rich amendments on heavy metal accumulation in rice (Oryza sativa L.) planted on multi-metal contaminated acidic soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mechanisms of stabilization by silicon-rich amendments of cadmium, zinc, copper and lead in a multi-metal contaminated acidic soil and the mitigation of metal accumulation in rice were investigated in this study. The results from a pot experiment indicated that the application of fly ash (20 and...

  4. Synergistic effects of the SAPK/JNK and the proteasome pathway on glial fibrillary acidic protein (GFAP) accumulation in Alexander disease.

    PubMed

    Tang, Guomei; Xu, Zhiheng; Goldman, James E

    2006-12-15

    Protein aggregates in astrocytes that contain glial fibrillary acidic protein (GFAP), small heat shock proteins, and ubiquitinated proteins are termed Rosenthal fibers and characterize Alexander disease, a leukodystrophy caused by heterozygous mutations in GFAP. The mechanisms responsible for the massive accumulation of GFAP in Alexander disease remain unclear. In this study, we show that overexpression of both wild type and R239C mutant human GFAP led to cytoplasmic inclusions. GFAP accumulation also led to a decrease of proteasome activity and an activation of the MLK2-JNK pathway. In turn, the expression of activated mixed lineage kinases (MLKs) induced JNK activation and increased GFAP accumulation, whereas blocking the JNK pathway decreased GFAP accumulation. Activated MLK also inhibited proteasome function. A direct inhibition of proteasome function pharmacologically further activated JNK. Our data suggest a synergistic interplay between the proteasome and the SAPK/JNK pathway in the context of GFAP accumulation. Feedback interactions among GFAP accumulation, SAPK/JNK activation, and proteasomal hypofunction cooperate to produce further protein accumulation and cellular stress responses.

  5. Metabolic pathways promoting intrahepatic fatty acid accumulation in methionine and choline deficiency: implications for the pathogenesis of steatohepatitis.

    PubMed

    Macfarlane, David P; Zou, Xiantong; Andrew, Ruth; Morton, Nicholas M; Livingstone, Dawn E W; Aucott, Rebecca L; Nyirenda, Moffat J; Iredale, John P; Walker, Brian R

    2011-02-01

    The pathological mechanisms that distinguish simple steatosis from steatohepatitis (or NASH, with consequent risk of cirrhosis and hepatocellular cancer) remain incompletely defined. Whereas both a methionine- and choline-deficient diet (MCDD) and a choline-deficient diet (CDD) lead to hepatic triglyceride accumulation, MCDD alone is associated with hepatic insulin resistance and inflammation (steatohepatitis). We used metabolic tracer techniques, including stable isotope ([¹³C₄]palmitate) dilution and mass isotopomer distribution analysis (MIDA) of [¹³C₂]acetate, to define differences in intrahepatic fatty acid metabolism that could explain the contrasting effect of MCDD and CDD on NASH in C57Bl6 mice. Compared with control-supplemented (CS) diet, liver triglyceride pool sizes were similarly elevated in CDD and MCDD groups (24.37 ± 2.4, 45.94 ± 3.9, and 43.30 ± 3.5 μmol/liver for CS, CDD, and MCDD, respectively), but intrahepatic neutrophil infiltration and plasma alanine aminotransferase (31 ± 3, 48 ± 4, 231 ± 79 U/l, P < 0.05) were elevated only in MCDD mice. However, despite loss of peripheral fat in MCDD mice, neither the rate of appearance of palmitate (27.2 ± 3.5, 26.3 ± 2.3, and 28.3 ± 3.5 μmol·kg⁻¹·min⁻¹) nor the contribution of circulating fatty acids to the liver triglyceride pool differed between groups. Unlike CDD, MCDD had a defect in hepatic triglyceride export that was confirmed using intravenous tyloxapol (142 ± 21, 122 ± 15, and 80 ± 7 mg·kg⁻¹·h⁻¹, P < 0.05). Moreover, hepatic de novo lipogenesis was significantly elevated in the MCDD group only (1.4 ± 0.3, 2.3 ± 0.4, and 3.4 ± 0.4 μmol/day, P < 0.01). These findings suggest that important alterations in hepatic fatty acid metabolism may promote the development of steatohepatitis. Similar mechanisms may predispose to hepatocyte damage in human NASH.

  6. Amino acid substitutions in the poliovirus maturation cleavage site affect assembly and result in accumulation of provirions.

    PubMed Central

    Ansardi, D C; Morrow, C D

    1995-01-01

    The assembly of infectious poliovirus virions requires a proteolytic cleavage between an asparagine-serine amino acid pair (the maturation cleavage site) in VP0 after encapsidation of the genomic RNA. In this study, we have investigated the effects that mutations in the maturation cleavage site have on P1 polyprotein processing, assembly of subviral intermediates, and encapsidation of the viral genomic RNA. We have made mutations in the maturation cleavage site which change the asparagine-serine amino acid pair to either glutamine-glycine or threonine-serine. The mutations were created by site-directed mutagenesis of P1 cDNAs which were recombined into wild-type vaccinia virus to generate recombinant vaccinia viruses. The P1 polyproteins expressed from the recombinant vaccinia viruses were analyzed for proteolytic processing and assembly defects in cells coinfected with a recombinant vaccinia virus (VV-P3) that expresses the poliovirus 3CD protease. A trans complementation system using a defective poliovirus genome was utilized to assess the capacity of the mutant P1 proteins to encapsidate genomic RNA (D. C. Ansardi, D. C. Porter, and C. D. Morrow, J. Virol. 67:3684-3690, 1993). The mutant P1 proteins containing the glutamine-glycine amino acid pair (VP4-QG) and the threonine-serine pair (VP4-TS) were processed by 3CD provided in trans from VV-P3. The processed capsid proteins VP0, VP3, and VP1 derived from the mutant precursor VP4-QG were unstable and failed to assemble into subviral structures in cells coinfected with VV-P3. However, the capsid proteins derived from VP4-QG did assemble into empty-capsid-like structures in the presence of the defective poliovirus genome. In contrast, the capsid proteins derived from processing of the VP4-TS mutant assembled into subviral intermediates both in the presence and in the absence of the defective genome RNA. By a sedimentation analysis, we determined that the capsid proteins derived from the VP4-TS precursor

  7. Jasmonic acid distribution and action in plants: regulation during development and response to biotic and abiotic stress.

    PubMed

    Creelman, R A; Mullet, J E

    1995-05-09

    Jasmonic acid (JA) is a naturally occurring growth regulator found in higher plants. Several physiological roles have been described for this compound (or a related compound, methyl jasmonate) during plant development and in response to biotic and abiotic stress. To accurately determine JA levels in plant tissue, we have synthesized JA containing 13C for use as an internal standard with an isotopic composition of [225]:[224] 0.98:0.02 compared with [225]:[224] 0.15:0.85 for natural material. GC analysis (flame ionization detection and MS) indicate that the internal standard is composed of 92% 2-(+/-)-[13C]JA and 8% 2-(+/-)-7-iso-[13C]JA. In soybean plants, JA levels were highest in young leaves, flowers, and fruit (highest in the pericarp). In soybean seeds and seedlings, JA levels were highest in the youngest organs including the hypocotyl hook, plumule, and 12-h axis. In soybean leaves that had been dehydrated to cause a 15% decrease in fresh weight, JA levels increased approximately 5-fold within 2 h and declined to approximately control levels by 4 h. In contrast, a lag time of 1-2 h occurred before abscisic acid accumulation reached a maximum. These results will be discussed in the context of multiple pathways for JA biosynthesis and the role of JA in plant development and responses to environmental signals.

  8. Nitrite accumulation from simultaneous free-ammonia and free-nitrous-acid inhibition and oxygen limitation in a continuous-flow biofilm reactor.

    PubMed

    Park, Seongjun; Chung, Jinwook; Rittmann, Bruce E; Bae, Wookeun

    2015-01-01

    To achieve nitrite accumulation for shortcut biological nitrogen removal (SBNR) in a biofilm process, we explored the simultaneous effects of oxygen limitation and free ammonia (FA) and free nitrous acid (FNA) inhibition in the nitrifying biofilm. We used the multi-species nitrifying biofilm model (MSNBM) to identify conditions that should or should not lead to nitrite accumulation, and evaluated the effectiveness of those conditions with experiments in continuous flow biofilm reactors (CFBRs). CFBR experiments were organized into four sets with these expected outcomes based on the MSNBM as follows: (i) Control, giving full nitrification; (ii) oxygen limitation, giving modest long-term nitrite build up; (iii) FA inhibition, giving no long-term nitrite accumulation; and (iv) FA inhibition plus oxygen limitation, giving major long-term nitrite accumulation. Consistent with MSNBM predictions, the experimental results showed that nitrite accumulated in sets 2-4 in the short term, but long-term nitrite accumulation was maintained only in sets 2 and 4, which involved oxygen limitation. Furthermore, nitrite accumulation was substantially greater in set 4, which also included FA inhibition. However, FA inhibition (and accompanying FNA inhibition) alone in set 3 did not maintained long-term nitrite accumulation. Nitrite-oxidizing bacteria (NOB) activity batch tests confirmed that little NOB or only a small fraction of NOB were present in the biofilms for sets 4 and 2, respectively. The experimental data supported the previous modeling results that nitrite accumulation could be achieved with a lower ammonium concentration than had been required for a suspended-growth process. Additional findings were that the biofilm exposed to low dissolved oxygen (DO) limitation and FA inhibition was substantially denser and probably had a lower detachment rate.

  9. Chronic administration of palmitoleic acid reduces insulin resistance and hepatic lipid accumulation in KK-Ay Mice with genetic type 2 diabetes

    PubMed Central

    2011-01-01

    Background Studies have demonstrated the beneficial effect of palmitoleic acid (C16:1 n-7) on reducing muscle insulin resistance and preventing beta-cell apoptosis. However, the effect of palmitoleic acid on diabetes remains to be elucidated. The aim of this study was to examine the antidiabetic effect of palmitoleic acid in KK-Ay mice, a spontaneous model for studies of obese type 2 diabetes with low insulin sensitivity. Methods KK-Ay mice were orally administered vehicle, 300 mg/kg of palmitoleic acid, or 300 mg/kg of palmitic acid (C16:0) on a daily basis for 4 weeks. Results Palmitoleic acid reduced body weight increase, ameliorated the development of hyperglycemia and hypertriglyceridemia, and improved insulin sensitivity. In addition, hepatic characteristics were significantly affected, as weight of the liver and hepatic triglyceride levels were lower in the palmitoleic acid group when compared to the control (vehicle and palmitic acid groups). Oil red O staining clearly indicated reduced hepatic lipid accumulation in response to palmitoleic acid. Furthermore, palmitoleic acid down-regulated mRNA expressions of proinflammatory adipocytokine genes (TNFα and resistin) in white adipose tissue and lipogenic genes (SREBP-1, FAS, and SCD-1) in liver. Conclusions These results suggest that palmitoleic acid improves hyperglycemia and hypertriglyceridemia by increasing insulin sensitivity, in part owing to suppressing proinflammatory gene expressions and improving hepatic lipid metabolism in diabetic mice. PMID:21774832

  10. Fish oil omega-3 fatty acids partially prevent lipid-induced insulin resistance in human skeletal muscle without limiting acylcarnitine accumulation.

    PubMed

    Stephens, Francis B; Mendis, Buddhike; Shannon, Chris E; Cooper, Scott; Ortori, Catharine A; Barrett, David A; Mansell, Peter; Tsintzas, Kostas

    2014-09-01

    Acylcarnitine accumulation in skeletal muscle and plasma has been observed in numerous models of mitochondrial lipid overload and insulin resistance. Fish oil n3PUFA (omega-3 polyunsaturated fatty acids) are thought to protect against lipid-induced insulin resistance. The present study tested the hypothesis that the addition of n3PUFA to an intravenous lipid emulsion would limit muscle acylcarnitine accumulation and reduce the inhibitory effect of lipid overload on insulin action. On three occasions, six healthy young men underwent a 6-h euglycaemic-hyperinsulinaemic clamp accompanied by intravenous infusion of saline (Control), 10% Intralipid® [n6PUFA (omega-6 polyunsaturated fatty acids)] or 10% Intralipid®+10% Omegaven® (2:1; n3PUFA). The decline in insulin-stimulated whole-body glucose infusion rate, muscle PDCa (pyruvate dehydrogenase complex activation) and glycogen storage associated with n6PUFA compared with Control was prevented with n3PUFA. Muscle acetyl-CoA accumulation was greater following n6PUFA compared with Control and n3PUFA, suggesting that mitochondrial lipid overload was responsible for the lower insulin action observed. Despite these favourable metabolic effects of n3PUFA, accumulation of total muscle acylcarnitine was not attenuated when compared with n6PUFA. These findings demonstrate that n3PUFA exert beneficial effects on insulin-stimulated skeletal muscle glucose storage and oxidation independently of total acylcarnitine accumulation, which does not always reflect mitochondrial lipid overload.

  11. Successful high-level accumulation of fish oil omega-3 long-chain polyunsaturated fatty acids in a transgenic oilseed crop.

    PubMed

    Ruiz-Lopez, Noemi; Haslam, Richard P; Napier, Johnathan A; Sayanova, Olga

    2014-01-01

    Omega-3 (also called n-3) long-chain polyunsaturated fatty acids (≥C20; LC-PUFAs) are of considerable interest, based on clear evidence of dietary health benefits and the concurrent decline of global sources (fish oils). Generating alternative transgenic plant sources of omega-3 LC-PUFAs, i.e. eicosapentaenoic acid (20:5 n-3, EPA) and docosahexaenoic acid (22:6 n-3, DHA) has previously proved problematic. Here we describe a set of heterologous genes capable of efficiently directing synthesis of these fatty acids in the seed oil of the crop Camelina sativa, while simultaneously avoiding accumulation of undesirable intermediate fatty acids. We describe two iterations: RRes_EPA in which seeds contain EPA levels of up to 31% (mean 24%), and RRes_DHA, in which seeds accumulate up to 12% EPA and 14% DHA (mean 11% EPA and 8% DHA). These omega-3 LC-PUFA levels are equivalent to those in fish oils, and represent a sustainable, terrestrial source of these fatty acids. We also describe the distribution of these non-native fatty acids within C. sativa seed lipids, and consider these data in the context of our current understanding of acyl exchange during seed oil synthesis.

  12. Aspartic Acid Racemization and Collagen Degradation Markers Reveal an Accumulation of Damage in Tendon Collagen That Is Enhanced with Aging*

    PubMed Central

    Thorpe, Chavaunne T.; Streeter, Ian; Pinchbeck, Gina L.; Goodship, Allen E.; Clegg, Peter D.; Birch, Helen L.

    2010-01-01

    Little is known about the rate at which protein turnover occurs in living tendon and whether the rate differs between tendons with different physiological roles. In this study, we have quantified the racemization of aspartic acid to calculate the age of the collagenous and non-collagenous components of the high strain injury-prone superficial digital flexor tendon (SDFT) and low strain rarely injured common digital extensor tendon (CDET) in a group of horses with a wide age range. In addition, the turnover of collagen was assessed indirectly by measuring the levels of collagen degradation markers (collagenase-generated neoepitope and cross-linked telopeptide of type I collagen). The fractional increase in d-Asp was similar (p = 0.7) in the SDFT (5.87 × 10−4/year) and CDET (5.82 × 10−4/year) tissue, and d/l-Asp ratios showed a good correlation with pentosidine levels. We calculated a mean (±S.E.) collagen half-life of 197.53 (±18.23) years for the SDFT, which increased significantly with horse age (p = 0.03) and was significantly (p < 0.001) higher than that for the CDET (34.03 (±3.39) years). Using similar calculations, the half-life of non-collagenous protein was 2.18 (±0.41) years in the SDFT and was significantly (p = 0.04) lower than the value of 3.51 (±0.51) years for the CDET. Collagen degradation markers were higher in the CDET and suggested an accumulation of partially degraded collagen within the matrix with aging in the SDFT. We propose that increased susceptibility to injury in older individuals results from an inability to remove partially degraded collagen from the matrix leading to reduced mechanical competence. PMID:20308077

  13. Dietary saturated fatty acids reduce hepatic lipid accumulation but induce fibrotic change in alcohol-fed rats

    PubMed Central

    Chen, Ya-Ling; Peng, Hsiang-Chi; Wang, Xiang-Dong

    2015-01-01

    Background In this study, we evaluated the influence of an ethanol-containing diet with high saturated fatty acids (SFAs) on alcoholic liver disease (ALD) in rats. Methods Male Wistar rats weighing about 160 g were divided into four groups: an ethanol (E) group fed an ethanol-containing liquid diet with 36% total calories as fat (corn oil, olive oil and safflower oil); a control (C) group pair-fed an isoenergetic diet without ethanol; an ethanol with saturated fat (EHS) group fed an ethanol-containing diet which contained 40% total calories as fat (90% lard); and a control with saturated fat (CHS) group fed an isoenergetic diet without ethanol, which contained 40% total calories as fat. Results After 8 weeks of treatment, the liver weight and plasma aspartate aminotransferase (AST) activities in E and EHS groups were significantly higher than those of C group. Significantly higher scores of inflammation, necrosis, and fatty changes were found in E group, whereas significantly higher scores of necrosis, bile duct hyperplasia, and fibrosis were found in EHS group. Although significantly lower plasma adiponectin concentrations were observed in both E and EHS groups, compared to C group, plasma adiponectin in EHS group was significantly higher than that in E group. There was no change in hepatic peroxisome proliferator activated receptor (PPAR)-α expression between E and C groups, and rats in EHS group showed a significantly elevated level compared to the other groups. A lower hepatic sirtuins (SIRT)-1 level was found in E group, but it did not reach statistical significance. Moreover, the highest plasma TGF-β1 level was found in EHS group. Compared to C group, the hepatic reduced glutathione/oxidized glutathione ratio and thiobarbituric acid (TBA)-reactive substance level were significantly increased in E and EHS groups; however, there was no significant difference between E and EHS groups. Significantly increased hepatic CYP2E1 expression was observed in both E and

  14. MAPK-dependent JA and SA signalling in Nicotiana attenuata affects plant growth and fitness during competition with conspecifics

    PubMed Central

    2012-01-01

    Background Induced defense responses to herbivores are generally believed to have evolved as cost-saving strategies that defer the fitness costs of defense metabolism until these defenses are needed. The fitness costs of jasmonate (JA)-mediated defenses have been well documented. Those of the early signaling units mediating induced resistance to herbivores have yet to be examined. Early signaling components that mediate herbivore-induced defense responses in Nicotiana attenuata, have been well characterized and here we examine their growth and fitness costs during competition with conspecifics. Two mitogen-activated protein kinases (MAPKs), salicylic acid (SA)-induced protein kinase (SIPK) and wound-induced protein kinase (WIPK) are rapidly activated after perception of herbivory and both kinases regulate herbivory-induced JA levels and JA-mediated defense metabolite accumulations. Since JA-induced defenses result in resource-based trade-offs that compromise plant productivity, we evaluated if silencing SIPK (irSIPK) and WIPK (irWIPK) benefits the growth and fitness of plants competiting with wild type (WT) plants, as has been shown for plants silenced in JA-signaling by the reduction of Lipoxygenase 3 (LOX3) levels. Results As expected, irWIPK and LOX3-silenced plants out-performed their competing WT plants. Surprisingly, irSIPK plants, which have the largest reductions in JA signaling, did not. Phytohormone profiling of leaves revealed that irSIPK plants accumulated higher levels of SA compared to WT. To test the hypothesis that these high levels of SA, and their presumed associated fitness costs of pathogen associated defenses in irSIPK plants had nullified the JA-deficiency-mediated growth benefits in these plants, we genetically reduced SA levels in irSIPK plants. Reducing SA levels partially recovered the biomass and fitness deficits of irSIPK plants. We also evaluated whether the increased fitness of plants with reduced SA or JA levels resulted from

  15. Tor-Sch9 deficiency activates catabolism of the ketone body-like acetic acid to promote trehalose accumulation and longevity.

    PubMed

    Hu, Jia; Wei, Min; Mirzaei, Hamed; Madia, Federica; Mirisola, Mario; Amparo, Camille; Chagoury, Shawna; Kennedy, Brian; Longo, Valter D

    2014-06-01

    In mammals, extended periods of fasting leads to the accumulation of blood ketone bodies including acetoacetate. Here we show that similar to the conversion of leucine to acetoacetate in fasting mammals, starvation conditions induced ketone body-like acetic acid generation from leucine in S. cerevisiae. Whereas wild-type and ras2Δ cells accumulated acetic acid, long-lived tor1Δ and sch9Δ mutants rapidly depleted it through a mitochondrial acetate CoA transferase-dependent mechanism, which was essential for lifespan extension. The sch9Δ-dependent utilization of acetic acid also required coenzyme Q biosynthetic genes and promoted the accumulation of intracellular trehalose. These results indicate that Tor-Sch9 deficiency extends longevity by switching cells to an alternative metabolic mode, in which acetic acid can be utilized for the storage of stress resistance carbon sources. These effects are reminiscent of those described for ketone bodies in fasting mammals and raise the possibility that the lifespan extension caused by Tor-S6K inhibition may also involve analogous metabolic changes in higher eukaryotes.

  16. Weak organic acid treatment causes a trehalose accumulation in low-pH cultures of Saccharomyces cerevisiae, not displayed by the more preservative-resistant Zygosaccharomyces bailii.

    PubMed

    Cheng, L; Moghraby, J; Piper, P W

    1999-01-01

    Weak organic acid food preservatives exert pronounced culture pH-dependent effects on both the heat-shock response and the thermotolerance of Saccharomyces cerevisiae. In low-pH cultures, they inhibit this stress response and cause strong induction of respiratory-deficient petites amongst the survivors of lethal heat treatment. In higher pH cultures, 25 degrees C sorbic acid treatment causes a strong induction of thermotolerance without inducing the heat-shock response. In this study we show that trehalose, a major stress protectant, accumulates rapidly in S. cerevisiae exposed to sorbate at low pH. In pH 3.5 cultures, a 25 degrees C sorbate treatment is as effective as a 39 degrees C heat shock in inducing trehalose. This weak-acid-induced trehalose accumulation is enhanced in the pfk1 S. cerevisiae mutant, indicating that it arises through inhibition of glycolysis at the phosphofructokinase step. The more preservative-resistant food spoilage yeast Zygosaccharomyces bailii differs from S. cerevisiae in that: (1) its basal thermotolerance is not strongly affected by culture pH; (2) it does not display trehalose accumulation in response to 25 degrees C sorbate treatment at low pH; and (3) there is no induction of respiratory-deficient petites during lethal heating with sorbate. This probably reflects Z. bailii being both petite-negative and better equipped for maintenance of homeostasis during weak-acid, pH or high-temperature stress.

  17. Effects of MeJA on Arabidopsis metabolome under endogenous JA deficiency

    PubMed Central

    Cao, Jingjing; Li, Mengya; Chen, Jian; Liu, Pei; Li, Zhen

    2016-01-01

    Jasmonates (JAs) play important roles in plant growth, development and defense. Comprehensive metabolomics profiling of plants under JA treatment provides insights into the interaction and regulation network of plant hormones. Here we applied high resolution mass spectrometry based metabolomics approach on Arabidopsis wild type and JA synthesis deficiency mutant opr3. The effects of exogenous MeJA treatment on the metabolites of opr3 were investigated. More than 10000 ion signals were detected and more than 2000 signals showed significant variation in different genotypes and treatment groups. Multivariate statistic analyses (PCA and PLS-DA) were performed and a differential compound library containing 174 metabolites with high resolution precursor ion-product ions pairs was obtained. Classification and pathway analysis of 109 identified compounds in this library showed that glucosinolates and tryptophan metabolism, amino acids and small peptides metabolism, lipid metabolism, especially fatty acyls metabolism, were impacted by endogenous JA deficiency and exogenous MeJA treatment. These results were further verified by quantitative reverse transcription PCR (RT-qPCR) analysis of 21 related genes involved in the metabolism of glucosinolates, tryptophan and α-linolenic acid pathways. The results would greatly enhance our understanding of the biological functions of JA. PMID:27883040

  18. Effects of MeJA on Arabidopsis metabolome under endogenous JA deficiency

    NASA Astrophysics Data System (ADS)

    Cao, Jingjing; Li, Mengya; Chen, Jian; Liu, Pei; Li, Zhen

    2016-11-01

    Jasmonates (JAs) play important roles in plant growth, development and defense. Comprehensive metabolomics profiling of plants under JA treatment provides insights into the interaction and regulation network of plant hormones. Here we applied high resolution mass spectrometry based metabolomics approach on Arabidopsis wild type and JA synthesis deficiency mutant opr3. The effects of exogenous MeJA treatment on the metabolites of opr3 were investigated. More than 10000 ion signals were detected and more than 2000 signals showed significant variation in different genotypes and treatment groups. Multivariate statistic analyses (PCA and PLS-DA) were performed and a differential compound library containing 174 metabolites with high resolution precursor ion-product ions pairs was obtained. Classification and pathway analysis of 109 identified compounds in this library showed that glucosinolates and tryptophan metabolism, amino acids and small peptides metabolism, lipid metabolism, especially fatty acyls metabolism, were impacted by endogenous JA deficiency and exogenous MeJA treatment. These results were further verified by quantitative reverse transcription PCR (RT-qPCR) analysis of 21 related genes involved in the metabolism of glucosinolates, tryptophan and α-linolenic acid pathways. The results would greatly enhance our understanding of the biological functions of JA.

  19. Dietary supplementation with phytosterol and ascorbic acid reduces body mass accumulation and alters food transit time in a diet-induced obesity mouse model

    PubMed Central

    2011-01-01

    Previous research indicates that animals fed a high fat (HF) diet supplemented with disodium ascorbyl phytostanyl phosphate (DAPP) exhibit reduced mass accumulation when compared to HF control. This compound is a water-soluble phytostanol ester and consists of a hydrophobic plant stanol covalently bonded to ascorbic acid (Vitamin C). To provide insight into the mechanism of this response, we examined the in vivo effects of a high fat diet supplemented with ascorbic acid (AA) in the presence and absence of unesterified phytosterols (PS), and set out to establish whether the supplements have a synergistic effect in a diet-induced obesity mouse model. Our data indicate that HF diet supplementation with a combination of 1% w/w phytosterol and 1% w/w ascorbic acid results in reduced mass accumulation, with mean differences in absolute mass between PSAA and HF control of 10.05%; and differences in mass accumulation of 21.6% (i.e. the PSAA group gained on average 21% less mass each week from weeks 7-12 than the HF control group). In our previous study, the absolute mass difference between the 2% DAPP and HF control was 41%, while the mean difference in mass accumulation between the two groups for weeks 7-12 was 67.9%. Mass loss was not observed in animals supplemented with PS or AA alone. These data suggest that the supplements are synergistic with respect to mass accumulation, and the esterification of the compounds further potentiates the response. Our data also indicate that chronic administration of PS, both in the presence and absence of AA, results in changes to fecal output and food transit time, providing insight into the possibility of long-term changes in intestinal function related to PS supplementation. PMID:21711516

  20. SIZ1 deficiency causes reduced stomatal aperture and enhanced drought tolerance via controlling salicylic acid-induced accumulation of reactive oxygen species in Arabidopsis.

    PubMed

    Miura, Kenji; Okamoto, Hiroyuki; Okuma, Eiji; Shiba, Hayato; Kamada, Hiroshi; Hasegawa, Paul M; Murata, Yoshiyuki

    2013-01-01

    Transpiration and gas exchange occur through stomata. Thus, the control of stomatal aperture is important for the efficiency and regulation of water use, and for the response to drought. Here, we demonstrate that SIZ1-mediated endogenous salicylic acid (SA) accumulation plays an important role in stomatal closure and drought tolerance. siz1 reduced stomatal apertures. The reduced stomatal apertures of siz1 were inhibited by the application of peroxidase inhibitors, salicylhydroxamic acid and azide, which inhibits SA-dependent reactive oxygen species (ROS) production, but not by an NADPH oxidase inhibitor, diphenyl iodonium chloride, which inhibits ABA-dependent ROS production. Furthermore, the introduction of nahG into siz1, which reduces SA accumulation, restored stomatal opening. Stomatal closure is generally induced by water deficit. The siz1 mutation caused drought tolerance, whereas nahG siz1 suppressed the tolerant phenotype. Drought stresses also induced expression of SA-responsive genes, such as PR1 and PR2. Furthermore, other SA-accumulating mutants, cpr5 and acd6, exhibited stomatal closure and drought tolerance, and nahG suppressed the phenotype of cpr5 and acd6, as did siz1 and nahG siz1. Together, these results suggest that SIZ1 negatively affects stomatal closure and drought tolerance through the accumulation of SA.

  1. Characterization of major ripening events during softening in grape: turgor, sugar accumulation, abscisic acid metabolism, colour development, and their relationship with growth.

    PubMed

    Castellarin, Simone D; Gambetta, Gregory A; Wada, Hiroshi; Krasnow, Mark N; Cramer, Grant R; Peterlunger, Enrico; Shackel, Kenneth A; Matthews, Mark A

    2016-02-01

    Along with sugar accumulation and colour development, softening is an important physiological change during the onset of ripening in fruits. In this work, we investigated the relationships among major events during softening in grape (Vitis vinifera L.) by quantifying elasticity in individual berries. In addition, we delayed softening and inhibited sugar accumulation using a mechanical growth-preventing treatment in order to identify processes that are sugar and/or growth dependent. Ripening processes commenced on various days after anthesis, but always at similarly low elasticity and turgor. Much of the softening occurred in the absence of other changes in berry physiology investigated here. Several genes encoding key cell wall-modifying enzymes were not up-regulated until softening was largely completed, suggesting softening may result primarily from decreases in turgor. Similarly, there was no decrease in solute potential, increase in sugar concentration, or colour development until elasticity and turgor were near minimum values, and these processes were inhibited when berry growth was prevented. Increases in abscisic acid occurred early during softening and in the absence of significant expression of the V. vinifera 9-cis-epoxycarotenoid dioxygenases. However, these increases were coincident with decreases in the abscisic acid catabolite diphasic acid, indicating that initial increases in abscisic acid may result from decreases in catabolism and/or exogenous import. These data suggest that softening, decreases in turgor, and increases in abscisic acid represent some of the earliest events during the onset of ripening. Later, physical growth, further increases in abscisic acid, and the accumulation of sugar are integral for colour development.

  2. Characterization of major ripening events during softening in grape: turgor, sugar accumulation, abscisic acid metabolism, colour development, and their relationship with growth

    PubMed Central

    Castellarin, Simone D.; Gambetta, Gregory A.; Wada, Hiroshi; Krasnow, Mark N.; Cramer, Grant R.; Peterlunger, Enrico; Shackel, Kenneth A.; Matthews, Mark A.

    2016-01-01

    Along with sugar accumulation and colour development, softening is an important physiological change during the onset of ripening in fruits. In this work, we investigated the relationships among major events during softening in grape (Vitis vinifera L.) by quantifying elasticity in individual berries. In addition, we delayed softening and inhibited sugar accumulation using a mechanical growth-preventing treatment in order to identify processes that are sugar and/or growth dependent. Ripening processes commenced on various days after anthesis, but always at similarly low elasticity and turgor. Much of the softening occurred in the absence of other changes in berry physiology investigated here. Several genes encoding key cell wall-modifying enzymes were not up-regulated until softening was largely completed, suggesting softening may result primarily from decreases in turgor. Similarly, there was no decrease in solute potential, increase in sugar concentration, or colour development until elasticity and turgor were near minimum values, and these processes were inhibited when berry growth was prevented. Increases in abscisic acid occurred early during softening and in the absence of significant expression of the V. vinifera 9-cis-epoxycarotenoid dioxygenases. However, these increases were coincident with decreases in the abscisic acid catabolite diphasic acid, indicating that initial increases in abscisic acid may result from decreases in catabolism and/or exogenous import. These data suggest that softening, decreases in turgor, and increases in abscisic acid represent some of the earliest events during the onset of ripening. Later, physical growth, further increases in abscisic acid, and the accumulation of sugar are integral for colour development. PMID:26590311

  3. Biochemical basis of 5-aminolaevulinic acid-induced protoporphyrin IX accumulation: a study in patients with (pre)malignant lesions of the oesophagus.

    PubMed Central

    Hinnen, P.; de Rooij, F. W.; van Velthuysen, M. L.; Edixhoven, A.; van Hillegersberg, R.; Tilanus, H. W.; Wilson, J. H.; Siersema, P. D.

    1998-01-01

    Administration of 5-aminolaevulinic acid (ALA) leads to porphyrin accumulation in malignant and premalignant tissues, and ALA is used as a prodrug in photodynamic therapy (PDT). To understand the mechanism of porphyrin accumulation after the administration of ALA and to investigate whether ALA-induced protoporphyrin IX might be a suitable photosensitizer in Barrett's oesophagus and adenocarcinoma, we determined the activities of porphobilinogen deaminase (PBG-D) and ferrochelatase (FC) in various malignant and premalignant as well as in normal tissues of the human oesophagus. A PDT power index for ALA-induced porphyrin accumulation, the ratio of PBG-D to FC normalized for the normal squamous epithelium of the oesophagus, was calculated to evaluate intertissue variation in the ability to accumulate porphyrins. In malignant and premalignant tissue a twofold increased PBG-D activity and a marginally increased FC activity was seen compared with normal squamous epithelium. A significantly increased PDT power index in Barrett's epithelium and adenocarcinoma was found. Our results suggest that, after the administration of ALA, porphyrins will accumulate in a greater amount in Barrett's epithelium and adenocarcinoma of the oesophagus because of an imbalance between PBG-D and FC activities. The PDT power index here defined might be a useful indicative parameter for predicting the susceptibility of these tissues to ALA-PDT. PMID:9744510

  4. Effect of light quality on the accumulation of photosynthetic pigments, proteins and mycosporine-like amino acids in the red alga Porphyra leucosticta (Bangiales, Rhodophyta).

    PubMed

    Korbee, Nathalie; Figueroa, Félix L; Aguilera, José

    2005-08-01

    The effect of different light qualities (white, blue, green, yellow and red light) on photosynthesis, measured as chlorophyll fluorescence, and the accumulation of photosynthetic pigments, proteins and the UV-absorbing mycosporine-like amino acids (MAAs) was studied in the red alga Porphyra leucosticta. Blue light promoted the highest accumulation of nitrogen metabolism derived compounds i.e., MAAs, phycoerythrin and proteins in previously N-starved algae after seven days culture in ammonium enriched medium. Similar results were observed in the culture under white light. In contrast, the lowest photosynthetic capacity i.e., lowest electron transport rate and lowest photosynthetic efficiency as well as the growth rate were found under blue light, while higher values were found in red and white lights. Blue light favored the accumulation of the MAAs porphyra-334, palythine and asterina-330 in P. leucosticta. However, white, green, yellow and red lights favored the accumulation of shinorine. The increase of porphyra-334, palythine and asterina-330 occurred in blue light simultaneous to a decrease in shinorine. The accumulation of MAAs and other nitrogenous compounds in P. leucosticta under blue light could not be attributed to photosynthesis and the action of a non-photosynthetic blue light photoreceptor is suggested. A non-photosynthetic photoreceptor could be also involved in the MAAs interconversion pathways in P. leucosticta.

  5. Accumulated SET protein up-regulates and interacts with hnRNPK, increasing its binding to nucleic acids, the Bcl-xS repression, and cellular proliferation

    SciTech Connect

    Almeida, Luciana O.; Garcia, Cristiana B.; Matos-Silva, Flavia A.; Curti, Carlos; Leopoldino, Andréia M.

    2014-02-28

    Highlights: • hnRNPK is a new target of SET. • SET regulates hnRNPK. • SET and hnRNPK accumulation promotes tumorigenesis. • SET accumulation is a potential model to study genes regulated by SET-hnRNPK. - Abstract: SET and hnRNPK are proteins involved in gene expression and regulation of cellular signaling. We previously demonstrated that SET accumulates in head and neck squamous cell carcinoma (HNSCC); hnRNPK is a prognostic marker in cancer. Here, we postulate that SET and hnRNPK proteins interact to promote tumorigenesis. We performed studies in HEK293 and HNSCC (HN6, HN12, and HN13) cell lines with SET/hnRNPK overexpression and knockdown, respectively. We found that SET and/or hnRNPK protein accumulation increased cellular proliferation. SET accumulation up-regulated hnRNPK mRNA and total/phosphorylated protein, promoted hnRNPK nuclear location, and reduced Bcl-x mRNA levels. SET protein directly interacted with hnRNPK, increasing both its binding to nucleic acids and Bcl-xS repression. We propose that hnRNPK should be a new target of SET and that SET–hnRNPK interaction, in turn, has potential implications in cell survival and malignant transformation.

  6. Evolution of the capsid protein genes of foot-and-mouth disease virus: antigenic variation without accumulation of amino acid substitutions over six decades.

    PubMed Central

    Martínez, M A; Dopazo, J; Hernández, J; Mateu, M G; Sobrino, F; Domingo, E; Knowles, N J

    1992-01-01

    The genetic diversification of foot-and-mouth disease virus (FMDV) of serotype C over a 6-decade period was studied by comparing nucleotide sequences of the capsid protein-coding regions of viruses isolated in Europe, South America, and The Philippines. Phylogenetic trees were derived for VP1 and P1 (VP1, VP2, VP3, and VP4) RNAs by using the least-squares method. Confidence intervals of the derived phylogeny (significance levels of nodes and standard deviations of branch lengths) were placed by application of the bootstrap resampling method. These procedures defined six highly significant major evolutionary lineages and a complex network of sublines for the isolates from South America. In contrast, European isolates are considerably more homogeneous, probably because of the vaccine origin of several of them. The phylogenetic analysis suggests that FMDV CGC Ger/26 (one of the earliest FMDV isolates available) belonged to an evolutionary line which is now apparently extinct. Attempts to date the origin (ancestor) of the FMDVs analyzed met with considerable uncertainty, mainly owing to the stasis noted in European viruses. Remarkably, the evolution of the capsid genes of FMDV was essentially associated with linear accumulation of silent mutations but continuous accumulation of amino acid substitutions was not observed. Thus, the antigenic variation attained by FMDV type C over 6 decades was due to fluctuations among limited combinations of amino acid residues without net accumulation of amino acid replacements over time. PMID:1316467

  7. Abscisic acid-induced nitric oxide and proline accumulation in independent pathways under water-deficit stress during seedling establishment in Medicago truncatula.

    PubMed

    Planchet, Elisabeth; Verdu, Isabelle; Delahaie, Julien; Cukier, Caroline; Girard, Clément; Morère-Le Paven, Marie-Christine; Limami, Anis M

    2014-05-01

    Nitric oxide (NO) production and amino acid metabolism modulation, in particular abscisic acid (ABA)-dependent proline accumulation, are stimulated in planta by most abiotic stresses. However, the relationship between NO production and proline accumulation under abiotic stress is still poorly understood, especially in the early phases of plant development. To unravel this question, this work investigated the tight relationship between NO production and proline metabolism under water-deficit stress during seedling establishment. Endogenous nitrate reductase-dependent NO production in Medicago truncatula seedlings increased in a time-dependent manner after short-term water-deficit stress. This water-deficit-induced endogenous NO accumulation was mediated through a ABA-dependent pathway and accompanied by an inhibition of seed germination, a loss of water content, and a decrease in elongation of embryo axes. Interestingly, a treatment with a specific NO scavenger (cPTIO) alleviated these water-deficit detrimental effects. However, the content of total amino acids, in particular glutamate and proline, as well as the expression of genes encoding enzymes of synthesis and degradation of proline were not affected by cPTIO treatment under water-deficit stress. Under normal conditions, exogenous NO donor stimulated neither the expression of P5CS2 nor the proline content, as observed after PEG treatment. These results strongly suggest that the modulation of proline metabolism is independent of NO production under short-term water-deficit stress during seedling establishment.

  8. Accumulation of a Threonine Biosynthetic Intermediate Attenuates General Amino Acid Control by Accelerating Degradation of Gcn4 via Pho85 and Cdk8

    PubMed Central

    Rawal, Yashpal; Qiu, Hongfang; Hinnebusch, Alan G.

    2014-01-01

    Gcn4 is a master transcriptional regulator of amino acid and vitamin biosynthetic enzymes subject to the general amino acid control (GAAC), whose expression is upregulated in response to amino acid starvation in Saccharomyces cerevisiae. We found that accumulation of the threonine pathway intermediate β-aspartate semialdehyde (ASA), substrate of homoserine dehydrogenase (Hom6), attenuates the GAAC transcriptional response by accelerating degradation of Gcn4, already an exceedingly unstable protein, in cells starved for isoleucine and valine. The reduction in Gcn4 abundance on ASA accumulation requires Cdk8/Srb10 and Pho85, cyclin-dependent kinases (CDKs) known to mediate rapid turnover of Gcn4 by the proteasome via phosphorylation of the Gcn4 activation domain under nonstarvation conditions. Interestingly, rescue of Gcn4 abundance in hom6 cells by elimination of SRB10 is not accompanied by recovery of transcriptional activation, while equivalent rescue of UAS-bound Gcn4 in hom6 pho85 cells restores greater than wild-type activation of Gcn4 target genes. These and other findings suggest that the two CDKs target different populations of Gcn4 on ASA accumulation, with Srb10 clearing mostly inactive Gcn4 molecules at the promoter that are enriched for sumoylation of the activation domain, and Pho85 clearing molecules unbound to the UAS that include both fully functional and inactive Gcn4 species. PMID:25079372

  9. EPA, an omega-3 fatty acid, induces apoptosis in human pancreatic cancer cells: role of ROS accumulation, caspase-8 activation, and autophagy induction.

    PubMed

    Fukui, Masayuki; Kang, Ki Sung; Okada, Kazushi; Zhu, Bao Ting

    2013-01-01

    In a recent study, we showed that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two common omega-3 fatty acids, can cause ROS accumulation and subsequently induce caspase-8-dependent apoptosis in human breast cancer cells (Kang et al. [2010], PLoS ONE 5: e10296). In this study, we showed that the pancreas has a unique ability to accumulate EPA at a level markedly higher than several other tissues analyzed. Based on this finding, we sought to further investigate the anticancer actions of EPA and its analog DHA in human pancreatic cancer cells using both in vitro and in vivo models. EPA and DHA were found to induce ROS accumulation and caspase-8-dependent cell death in human pancreatic cancer cells (MIA-PaCa-2 and Capan-2) in vitro. Feeding animals with a diet supplemented with 5% fish oil, which contains high levels of EPA and DHA, also strongly suppresses the growth of MIA-PaCa-2 human pancreatic cancer xenografts in athymic nude mice, by inducing oxidative stress and cell death. In addition, we showed that EPA can concomitantly induce autophagy in these cancer cells, and the induction of autophagy diminishes its ability to induce apoptotic cell death. It is therefore suggested that combination of EPA with an autophagy inhibitor may be a useful strategy in increasing the therapeutic effectiveness in pancreatic cancer.

  10. The Amidohydrolases IAR3 and ILL6 Contribute to Jasmonoyl-Isoleucine Hormone Turnover and Generate 12-Hydroxyjasmonic Acid Upon Wounding in Arabidopsis Leaves*

    PubMed Central

    Widemann, Emilie; Miesch, Laurence; Lugan, Raphaël; Holder, Emilie; Heinrich, Clément; Aubert, Yann; Miesch, Michel; Pinot, Franck; Heitz, Thierry

    2013-01-01

    Jasmonates (JAs) are a class of signaling compounds that mediate complex developmental and adaptative responses in plants. JAs derive from jasmonic acid (JA) through various enzymatic modifications, including conjugation to amino acids or oxidation, yielding an array of derivatives. The main hormonal signal, jasmonoyl-l-isoleucine (JA-Ile), has been found recently to undergo catabolic inactivation by cytochrome P450-mediated oxidation. We characterize here two amidohydrolases, IAR3 and ILL6, that define a second pathway for JA-Ile turnover during the wound response in Arabidopsis leaves. Biochemical and genetic evidence indicates that these two enzymes cleave the JA-Ile signal, but act also on the 12OH-JA-Ile conjugate. We also show that unexpectedly, the abundant accumulation of tuberonic acid (12OH-JA) after wounding originates partly through a sequential pathway involving (i) conjugation of JA to Ile, (ii) oxidation of the JA-Ile conjugate, and (iii) cleavage under the action of the amidohydrolases. The coordinated actions of oxidative and hydrolytic branches in the jasmonate pathway highlight novel mechanisms of JA-Ile hormone turnover and redefine the dynamic metabolic grid of jasmonate conversion in the wound response. PMID:24052260

  11. Jasmonic acid is a crucial signal transducer in heat shock induced sesquiterpene formation in Aquilaria sinensis.

    PubMed

    Xu, Yan-Hong; Liao, Yong-Cui; Zhang, Zheng; Liu, Juan; Sun, Pei-Wen; Gao, Zhi-Hui; Sui, Chun; Wei, Jian-He

    2016-02-23

    Agarwood, a highly valuable resinous and fragrant heartwood of Aquilaria plants, is widely used in traditional medicines, incense and perfume. Only when Aquilaria trees are wounded by external stimuli do they form agarwood sesquiterpene defensive compounds. Therefore, understanding the signaling pathway of wound-induced agarwood formation is important. Jasmonic acid (JA) is a well-characterized molecule that mediates a plant's defense response and secondary metabolism. However, little is known about the function of endogenous JA in agarwood sesquiterpene biosynthesis. Here, we report that heat shock can up-regulate the expression of genes in JA signaling pathway, induce JA production and the accumulation of agarwood sesquiterpene in A. sinensis cell suspension cultures. A specific inhibitor of JA, nordihydroguaiaretic acid (NDGA), could block the JA signaling pathway and reduce the accumulation of sesquiterpene compounds. Additionally, compared to SA and H2O2, exogenously supplied methyl jasmonate has the strongest stimulation effect on the production of sesquiterpene compounds. These results clearly demonstrate the central induction role of JA in heat-shock-induced sesquiterpene production in A. sinensis.

  12. Jasmonic acid is a crucial signal transducer in heat shock induced sesquiterpene formation in Aquilaria sinensis

    PubMed Central

    Xu, Yan-Hong; Liao, Yong-Cui; Zhang, Zheng; Liu, Juan; Sun, Pei-Wen; Gao, Zhi-Hui; Sui, Chun; Wei, Jian-He

    2016-01-01

    Agarwood, a highly valuable resinous and fragrant heartwood of Aquilaria plants, is widely used in traditional medicines, incense and perfume. Only when Aquilaria trees are wounded by external stimuli do they form agarwood sesquiterpene defensive compounds. Therefore, understanding the signaling pathway of wound-induced agarwood formation is important. Jasmonic acid (JA) is a well-characterized molecule that mediates a plant’s defense response and secondary metabolism. However, little is known about the function of endogenous JA in agarwood sesquiterpene biosynthesis. Here, we report that heat shock can up-regulate the expression of genes in JA signaling pathway, induce JA production and the accumulation of agarwood sesquiterpene in A. sinensis cell suspension cultures. A specific inhibitor of JA, nordihydroguaiaretic acid (NDGA), could block the JA signaling pathway and reduce the accumulation of sesquiterpene compounds. Additionally, compared to SA and H2O2, exogenously supplied methyl jasmonate has the strongest stimulation effect on the production of sesquiterpene compounds. These results clearly demonstrate the central induction role of JA in heat-shock-induced sesquiterpene production in A. sinensis. PMID:26902148

  13. Partial Activation of SA- and JA-Defensive Pathways in Strawberry upon Colletotrichum acutatum Interaction

    PubMed Central

    Amil-Ruiz, Francisco; Garrido-Gala, José; Gadea, José; Blanco-Portales, Rosario; Muñoz-Mérida, Antonio; Trelles, Oswaldo; de los Santos, Berta; Arroyo, Francisco T.; Aguado-Puig, Ana; Romero, Fernando; Mercado, José-Ángel; Pliego-Alfaro, Fernando; Muñoz-Blanco, Juan; Caballero, José L.

    2016-01-01

    Understanding the nature of pathogen host interaction may help improve strawberry (Fragaria × ananassa) cultivars. Plant resistance to pathogenic agents usually operates through a complex network of defense mechanisms mediated by a diverse array of signaling molecules. In strawberry, resistance to a variety of pathogens has been reported to be mostly polygenic and quantitatively inherited, making it difficult to associate molecular markers with disease resistance genes. Colletotrichum acutatum spp. is a major strawberry pathogen, and completely resistant cultivars have not been reported. Moreover, strawberry defense network components and mechanisms remain largely unknown and poorly understood. Assessment of the strawberry response to C. acutatum included a global transcript analysis, and acidic hormones SA and JA measurements were analyzed after challenge with the pathogen. Induction of transcripts corresponding to the SA and JA signaling pathways and key genes controlling major steps within these defense pathways was detected. Accordingly, SA and JA accumulated in strawberry after infection. Contrastingly, induction of several important SA, JA, and oxidative stress-responsive defense genes, including FaPR1-1, FaLOX2, FaJAR1, FaPDF1, and FaGST1, was not detected, which suggests that specific branches in these defense pathways (those leading to FaPR1-2, FaPR2-1, FaPR2-2, FaAOS, FaPR5, and FaPR10) were activated. Our results reveal that specific aspects in SA and JA dependent signaling pathways are activated in strawberry upon interaction with C. acutatum. Certain described defense-associated transcripts related to these two known signaling pathways do not increase in abundance following infection. This finding suggests new insight into a specific putative molecular strategy for defense against this pathogen. PMID:27471515

  14. Partial Activation of SA- and JA-Defensive Pathways in Strawberry upon Colletotrichum acutatum Interaction.

    PubMed

    Amil-Ruiz, Francisco; Garrido-Gala, José; Gadea, José; Blanco-Portales, Rosario; Muñoz-Mérida, Antonio; Trelles, Oswaldo; de Los Santos, Berta; Arroyo, Francisco T; Aguado-Puig, Ana; Romero, Fernando; Mercado, José-Ángel; Pliego-Alfaro, Fernando; Muñoz-Blanco, Juan; Caballero, José L

    2016-01-01

    Understanding the nature of pathogen host interaction may help improve strawberry (Fragaria × ananassa) cultivars. Plant resistance to pathogenic agents usually operates through a complex network of defense mechanisms mediated by a diverse array of signaling molecules. In strawberry, resistance to a variety of pathogens has been reported to be mostly polygenic and quantitatively inherited, making it difficult to associate molecular markers with disease resistance genes. Colletotrichum acutatum spp. is a major strawberry pathogen, and completely resistant cultivars have not been reported. Moreover, strawberry defense network components and mechanisms remain largely unknown and poorly understood. Assessment of the strawberry response to C. acutatum included a global transcript analysis, and acidic hormones SA and JA measurements were analyzed after challenge with the pathogen. Induction of transcripts corresponding to the SA and JA signaling pathways and key genes controlling major steps within these defense pathways was detected. Accordingly, SA and JA accumulated in strawberry after infection. Contrastingly, induction of several important SA, JA, and oxidative stress-responsive defense genes, including FaPR1-1, FaLOX2, FaJAR1, FaPDF1, and FaGST1, was not detected, which suggests that specific branches in these defense pathways (those leading to FaPR1-2, FaPR2-1, FaPR2-2, FaAOS, FaPR5, and FaPR10) were activated. Our results reveal that specific aspects in SA and JA dependent signaling pathways are activated in strawberry upon interaction with C. acutatum. Certain described defense-associated transcripts related to these two known signaling pathways do not increase in abundance following infection. This finding suggests new insight into a specific putative molecular strategy for defense against this pathogen.

  15. Aniline is an inducer, and not a precursor, for indole derivatives in Rubrivivax benzoatilyticus JA2.

    PubMed

    Mujahid, Mohammed; Sasikala, Ch; Ramana, Ch V

    2014-01-01

    Rubrivivax benzoatilyticus JA2 and other anoxygenic photosynthetic bacteria produce indole derivatives when exposed to aniline, a xenobiotic compound. Though this phenomenon has been reported previously, the role of aniline in the production of indoles is still a biochemical riddle. The present study aims at understanding the specific role of aniline (as precursor or stimulator) in the production of indoles and elucidating the biochemical pathway of indoles in aniline-exposed cells by using stable isotope approaches. Metabolic profiling revealed tryptophan accumulation only in aniline exposed cells along with indole 3-acetic acid (IAA) and indole 3-aldehyde (IAld), the two major catabolites of tryptophan. Deuterium labelled aniline feeding studies revealed that aniline is not a precursor of indoles in strain JA2. Further, production of indoles only in aniline-exposed cells suggests that aniline is an indoles stimulator. In addition, production of indoles depended on the presence of a carbon source, and production enhanced when carbon sources were added to the culture. Isotope labelled fumarate feeding identified, fumarate as the precursor of indole, indicating de novo synthesis of indoles. Glyphosate (shikimate pathway inhibitor) inhibited the indoles production, accumulation of tryptophan, IAA and IAld indicating that indoles synthesis in strain JA2 occurs via the de novo shikimate pathway. The up-regulation of anthranilate synthase gene and induction of anthranilate synthase activity correlated well with tryptophan production in strain JA2. Induction of tryptophan aminotransferase and tryptophan 2-monooxygenase activities corroborated well with IAA levels, suggesting that tryptophan catabolism occurs simultaneously in aniline exposed cells. Our study demonstrates that aniline (stress) stimulates tryptophan/indoles synthesis via the shikimate pathway by possibly modulating the metabolic pathway.

  16. Aniline Is an Inducer, and Not a Precursor, for Indole Derivatives in Rubrivivax benzoatilyticus JA2

    PubMed Central

    Mohammed, Mujahid; Ch, Sasikala; Ch, Ramana V.

    2014-01-01

    Rubrivivax benzoatilyticus JA2 and other anoxygenic photosynthetic bacteria produce indole derivatives when exposed to aniline, a xenobiotic compound. Though this phenomenon has been reported previously, the role of aniline in the production of indoles is still a biochemical riddle. The present study aims at understanding the specific role of aniline (as precursor or stimulator) in the production of indoles and elucidating the biochemical pathway of indoles in aniline-exposed cells by using stable isotope approaches. Metabolic profiling revealed tryptophan accumulation only in aniline exposed cells along with indole 3-acetic acid (IAA) and indole 3-aldehyde (IAld), the two major catabolites of tryptophan. Deuterium labelled aniline feeding studies revealed that aniline is not a precursor of indoles in strain JA2. Further, production of indoles only in aniline-exposed cells suggests that aniline is an indoles stimulator. In addition, production of indoles depended on the presence of a carbon source, and production enhanced when carbon sources were added to the culture. Isotope labelled fumarate feeding identified, fumarate as the precursor of indole, indicating de novo synthesis of indoles. Glyphosate (shikimate pathway inhibitor) inhibited the indoles production, accumulation of tryptophan, IAA and IAld indicating that indoles synthesis in strain JA2 occurs via the de novo shikimate pathway. The up-regulation of anthranilate synthase gene and induction of anthranilate synthase activity correlated well with tryptophan production in strain JA2. Induction of tryptophan aminotransferase and tryptophan 2-monooxygenase activities corroborated well with IAA levels, suggesting that tryptophan catabolism occurs simultaneously in aniline exposed cells. Our study demonstrates that aniline (stress) stimulates tryptophan/indoles synthesis via the shikimate pathway by possibly modulating the metabolic pathway. PMID:24533057

  17. Leaf and root glucosinolate profiles of Chinese cabbage (Brassica rapa ssp. pekinensis) as a systemic response to methyl jasmonate and salicylic acid elicitation.

    PubMed

    Zang, Yun-xiang; Ge, Jia-li; Huang, Ling-hui; Gao, Fei; Lv, Xi-shan; Zheng, Wei-wei; Hong, Seung-beom; Zhu, Zhu-jun

    2015-08-01

    Glucosinolates (GSs) are an important group of defensive phytochemicals mainly found in Brassicaceae. Plant hormones jasmonic acid (JA) and salicylic acid (SA) are major regulators of plant response to pathogen attack. However, there is little information about the interactive effect of both elicitors on inducing GS biosynthesis in Chinese cabbage (Brassica rapa ssp. pekinensis). In this study, we applied different concentrations of methyl jasmonate (MeJA) and/or SA onto the leaf and root of Chinese cabbage to investigate the time-course interactive profiles of GSs. Regardless of the site of the elicitation and the concentrations of the elicitors, the roots accumulated much more GSs and were more sensitive and more rapidly responsive to the elicitors than leaves. Irrespective of the elicitation site, MeJA had a greater inducing and longer lasting effect on GS accumulation than SA. All three components of indole GS (IGS) were detected along with aliphatic and aromatic GSs. However, IGS was a major component of total GSs that accumulated rapidly in both root and leaf tissues in response to MeJA and SA elicitation. Neoglucobrassicin (neoGBC) did not respond to SA but to MeJA in leaf tissue, while it responded to both SA and MeJA in root tissue. Conversion of glucobrassicin (GBC) to neoGBC occurred at a steady rate over 3 d of elicitation. Increased accumulation of 4-methoxy glucobrassicin (4-MGBC) occurred only in the root irrespective of the type of elicitors and the site of elicitation. Thus, accumulation of IGS is a major metabolic hallmark of SA- and MeJA-mediated systemic response systems. SA exerted an antagonistic effect on the MeJA-induced root GSs irrespective of the site of elicitation. However, SA showed synergistic and antagonistic effects on the MeJA-induced leaf GSs when roots and leaves are elicitated for 3 d, respectively.

  18. Effects of Jasmonic Acid on Embryo-Specific Processes in Brassica and Linum Oilseeds 1

    PubMed Central

    Wilen, Ronald W.; van Rooijen, Gijs J. H.; Pearce, David W.; Pharis, Richard P.; Holbrook, Larry A.; Moloney, Maurice M.

    1991-01-01

    A number of effects on embryogenesis of the putative phytohormone jasmonic acid (JA), and its methyl ester (MeJA), were investigated in two oilseed plants, repeseed (Brassica napus) and flax (Linum usitatissimum). Results from treatments with JA and MeJA were compared with those of a known effector of several aspects of embryogenesis, abscisic acid (ABA). Jasmonic acid was identified by gas chromatography-mass spectrometry as a naturally occurring substance in both plant species during embryo development. Both JA and MeJA can prevent precocious germination of B. napus microspore embryos and of cultured zygotic embryos of both species at an exogenous concentration of >1 micromolar. This dose-response was comparable with results obtained with ABA. Inhibitory effects were also observed on seed germination with all three growth regulators in rapeseed and flax. A number of molecular aspects of embryogenesis were also investigated. Expression of the B. napus storage protein genes (napin and cruciferin) was induced in both microspore embryos and zygotic embryos by the addition of 10 micromolar JA. The level of napin and cruciferin mRNA detected was similar to that observed when 10 micromolar ABA was applied to these embryos. For MeJA only slight increases in napin or cruciferin mRNA were observed at concentrations of 30 micromolar. Several oilbody-associated proteins were found to accumulate when the embryos were incubated with either JA or ABA in both species. The MeJA had little effect on oilbody protein synthesis. The implications of JA acting as a natural regulator of gene expression in zygotic embryogenesis are discussed. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:16667997

  19. High level accumulation of gamma linolenic acid (C18:3Δ6.9,12 cis) in transgenic safflower (Carthamus tinctorius) seeds.

    PubMed

    Nykiforuk, Cory L; Shewmaker, Christine; Harry, Indra; Yurchenko, Olga P; Zhang, Mei; Reed, Catherine; Oinam, Gunamani S; Zaplachinski, Steve; Fidantsef, Ana; Boothe, Joseph G; Moloney, Maurice M

    2012-04-01

    Gamma linolenic acid (GLA; C18:3Δ6,9,12 cis), also known as γ-Linolenic acid, is an important essential fatty acid precursor for the synthesis of very long chain polyunsaturated fatty acids and important pathways involved in human health. GLA is synthesized from linoleic acid (LA; C18:2Δ9,12 cis) by endoplasmic reticulum associated Δ6-desaturase activity. Currently sources of GLA are limited to a small number of plant species with poor agronomic properties, and therefore an economical and abundant commercial source of GLA in an existing crop is highly desirable. To this end, the seed oil of a high LA cultivated species of safflower (Carthamus tinctorius) was modified by transformation with Δ6-desaturase from Saprolegnia diclina resulting in levels exceeding 70% (v/v) of GLA. Levels around 50% (v/v) of GLA in seed oil was achieved when Δ12-/Δ6-desaturases from Mortierella alpina was over-expressed in safflower cultivars with either a high LA or high oleic (OA; C18:1Δ9 cis) background. The differences in the overall levels of GLA suggest the accumulation of the novel fatty acid was not limited by a lack of incorporation into the triacylgylcerol backbone (>66% GLA achieved), or correlated with gene dosage (GLA levels independent of gene copy number), but rather reflected the differences in Δ6-desaturase activity from the two sources. To date, these represent the highest accumulation levels of a newly introduced fatty acid in a transgenic crop. Events from these studies have been propagated and recently received FDA approval for commercialization as Sonova™400.

  20. Enhancement of Ganoderic Acid Accumulation by Overexpression of an N-Terminally Truncated 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Gene in the Basidiomycete Ganoderma lucidum

    PubMed Central

    Xu, Jun-Wei; Xu, Yi-Ning

    2012-01-01

    Ganoderic acids produced by Ganoderma lucidum, a well-known traditional Chinese medicinal mushroom, exhibit antitumor and antimetastasis activities. Genetic modification of G. lucidum is difficult but critical for the enhancement of cellular accumulation of ganoderic acids. In this study, a homologous genetic transformation system for G. lucidum was developed for the first time using mutated sdhB, encoding the iron-sulfur protein subunit of succinate dehydrogenase, as a selection marker. The truncated G. lucidum gene encoding the catalytic domain of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) was overexpressed by using the Agrobacterium tumefaciens-mediated transformation system. The results showed that the mutated sdhB successfully conferred carboxin resistance upon transformation. Most of the integrated transfer DNA (T-DNA) appeared as a single copy in the genome. Moreover, deregulated constitutive overexpression of the HMGR gene led to a 2-fold increase in ganoderic acid content. It also increased the accumulation of intermediates (squalene and lanosterol) and the upregulation of downstream genes such as those of farnesyl pyrophosphate synthase, squalene synthase, and lanosterol synthase. This study demonstrates that transgenic basidiomycete G. lucidum is a promising system to achieve metabolic engineering of the ganoderic acid pathway. PMID:22941092

  1. Uncoupling, metabolic inhibition and induction of mitochondrial permeability transition in rat liver mitochondria caused by the major long-chain hydroxyl monocarboxylic fatty acids accumulating in LCHAD deficiency.

    PubMed

    Hickmann, Fernanda Hermes; Cecatto, Cristiane; Kleemann, Daniele; Monteiro, Wagner Oliveira; Castilho, Roger Frigério; Amaral, Alexandre Umpierrez; Wajner, Moacir

    2015-01-01

    Patients with long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) deficiency commonly present liver dysfunction whose pathogenesis is unknown. We studied the effects of long-chain 3-hydroxylated fatty acids (LCHFA) that accumulate in LCHAD deficiency on liver bioenergetics using mitochondrial preparations from young rats. We provide strong evidence that 3-hydroxytetradecanoic (3HTA) and 3-hydroxypalmitic (3HPA) acids, the monocarboxylic acids that are found at the highest tissue concentrations in this disorder, act as metabolic inhibitors and uncouplers of oxidative phosphorylation. These conclusions are based on the findings that these fatty acids decreased ADP-stimulated (state 3) and uncoupled respiration, mitochondrial membrane potential and NAD(P)H content, and, in contrast, increased resting (state 4) respiration. We also verified that 3HTA and 3HPA markedly reduced Ca2+ retention capacity and induced swelling in Ca2+-loaded mitochondria. These effects were mediated by mitochondrial permeability transition (MPT) induction since they were totally prevented by the classical MPT inhibitors cyclosporin A and ADP, as well as by ruthenium red, a Ca2+ uptake blocker. Taken together, our data demonstrate that the major monocarboxylic LCHFA accumulating in LCHAD deficiency disrupt energy mitochondrial homeostasis in the liver. It is proposed that this pathomechanism may explain at least in part the hepatic alterations characteristic of the affected patients.

  2. Effects of organic acids on the photosynthetic and antioxidant properties and accumulations of heavy metals of Melilotus officinalis grown in Cu tailing.

    PubMed

    Han, Yulin; Wu, Xue; Gu, Jiguang; Zhao, Jiuzhou; Huang, Suzhen; Yuan, Haiyan; Fu, Jiajia

    2016-09-01

    The effect of citric acid (CA), acetic acid (Ac), and ethylene diamine tetraacetic acid (EDTA) on the photosynthetic and antioxidant properties and the accumulation of some heavy metals (HMs) of Melilotus officinalis seedling growing in Cu mine tailings for 25 days were studied. Results showed that the formation of photosynthesizing cells of M. officinalis was inhibited by EDTA at 2 mmol/kg. Photosynthetic pigment contents under EDTA of 2 mmol/kg were reduced by 26, 40, and 19 %, respectively, compared to the control. The proline contents in aboveground and underground parts increased as the level of EDTA was enhanced. CA and Ac enhanced the activities of superoxide dismutase (SOD) and peroxidase (POD) in the aboveground parts and EDTA inhibited the activity of POD in the underground parts. The addition of CA promoted significantly the growth of M. officinalis, while the biomass decreased significantly under 2 mmol/kg EDTA. Cu contents in the aboveground parts treated with 0.5 and 2.0 mmol/kg EDTA reached 175.50 and 265.17 μg/g dry weight, respectively. Ac and EDTA treatments promoted Cd to translocate from root to aboveground parts. The result indicated that M. officinalis was a tolerant species of Cu tailing and can be used to remediate Cu contaminated environment, and rationally utilization of organic acids, especially EDTA, in the phytoremediation can improve the growth and metals accumulation of M. officinalis.

  3. The Synthesis and Accumulation of Resveratrol Are Associated with Veraison and Abscisic Acid Concentration in Beihong (Vitis vinifera × Vitis amurensis) Berry Skin

    PubMed Central

    Wang, Junfang; Wang, Shuqin; Liu, Guotian; Edwards, Everard J.; Duan, Wei; Li, Shaohua; Wang, Lijun

    2016-01-01

    Resveratrols are polyphenolic secondary metabolites that can benefit human health, and only occur in a few plant families including Vitaceae. It has been reported that abscisic acid (ABA) can induce veraison (the onset of grape berry ripening) and may induce the accumulation of resveratrol in berry skin. However, the relationships between ABA, veraison, the accumulation of anthocyanins and the accumulation of resveratrol in the berry are poorly understood. This study attempted to answer this question through an investigation of the effect of applied ABA and fluridone (a synthetic inhibitor of ABA) on the biosynthesis and accumulation of ABA, anthocyanin, and resveratrol in Beihong (Vitis vinifera × Vitis amurensis) berry skin. Under natural conditions, resveratrol concentration was very low before 91 DAA (days after anthesis), i.e., 2 weeks after veraison, however, it increased sharply from this point to 126 DAA (maturity). Exogenous ABA applications all resulted in an increase in berry skin ABA and anthocyanin concentration, irrespective of the developmental stage at which the treatment occurred (20 and 10 days pre-veraison, veraison or 7 days post-veraison), thereby advancing veraison. In contrast, resveratrol concentration increased only when ABA was applied at 10 days pre-veraison or at veraison. As a result, the accumulation of resveratrol was associated with veraison in grape berry skin and this accumulation, together with that of anthocyanins, was associated with ABA concentration. The response of resveratrol biosynthesis in the berry skin to manipulation of ABA varied during berry development and was less sensitive to ABA than the response of anthocyanin biosynthesis. PMID:27857716

  4. Accumulate-Repeat-Accumulate-Accumulate-Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

    2004-01-01

    Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

  5. Increased beta-oxidation in muscle cells enhances insulin-stimulated glucose metabolism and protects against fatty acid-induced insulin resistance despite intramyocellular lipid accumulation.

    PubMed

    Perdomo, German; Commerford, S Renee; Richard, Ann-Marie T; Adams, Sean H; Corkey, Barbara E; O'Doherty, Robert M; Brown, Nicholas F

    2004-06-25

    Skeletal muscle insulin resistance may be aggravated by intramyocellular accumulation of fatty acid-derived metabolites that inhibit insulin signaling. We tested the hypothesis that enhanced fatty acid oxidation in myocytes should protect against fatty acid-induced insulin resistance by limiting lipid accumulation. L6 myotubes were transduced with adenoviruses encoding carnitine palmitoyltransferase I (CPT I) isoforms or beta-galactosidase (control). Two to 3-fold overexpression of L-CPT I, the endogenous isoform in L6 cells, proportionally increased oxidation of the long-chain fatty acids palmitate and oleate and increased insulin stimulation of [(14)C]glucose incorporation into glycogen by 60% while enhancing insulin-stimulated phosphorylation of p38MAPK. Incubation of control cells with 0.2 mm palmitate for 18 h caused accumulation of triacylglycerol, diacylglycerol, and ceramide (but not long-chain acyl-CoA) and decreased insulin-stimulated [(14)C]glucose incorporation into glycogen (60%), [(3)H]deoxyglucose uptake (60%), and protein kinase B phosphorylation (20%). In the context of L-CPT I overexpression, palmitate preincubation produced a relative decrease in insulin-stimulated incorporation of [(14)C]glucose into glycogen (60%) and [(3)H]deoxyglucose uptake (40%) but did not inhibit phosphorylation of protein kinase B. Due to the enhancement of insulin-stimulated glucose metabolism induced by L-CPT I overexpression itself, net insulin-stimulated incorporation of [(14)C]glucose into glycogen and [(3)H]deoxyglucose uptake in L-CPT I-transduced, palmitate-treated cells were significantly greater than in palmitate-treated control cells (71 and 75% greater, respectively). However, L-CPT I overexpression failed to decrease intracellular triacylglycerol, diacylglycerol, ceramide, or long-chain acyl-CoA. We propose that accelerated beta-oxidation in muscle cells exerts an insulin-sensitizing effect independently of changes in intracellular lipid content.

  6. Organic acids on the growth, anatomical structure, biochemical parameters and heavy metal accumulation of Iris lactea var. chinensis seedling growing in Pb mine tailings.

    PubMed

    Han, Yu-Lin; Huang, Su-Zhen; Yuan, Hai-Yan; Zhao, Jiu-Zhou; Gu, Ji-Guang

    2013-08-01

    The effect of citric acid (CA) and ethylene diamine tetraacetic acid (EDTA) on the growth, anatomical structure, physiological responses and lead (Pb) accumulation of Iris lactea var. chinensis seedling growing in Pb mine tailings for 30 days were studied. Results showed that the dry weights (DW) of roots decreased significantly under both levels of CA. The DWs of leaves and roots treated with 2 mmol/kg EDTA decreased significantly and were 23 and 54 %, respectively, lower than those of the control. The tolerant indexes of I. lactea var. chinensis under all treatments of organic acids were lower than control. The root tip anatomical structure was little affected under the treatments of 2 mmol/kg CA and 2 mmol/kg EDTA compared with control. However, the formation of photosynthesizing cells was inhibited by the treatment of 2 mmol/kg EDTA. The concentrations of chlorophyll a, chlorophyll b and total carotenoids in the leaves treated with 2 mmol/kg EDTA significantly decreased. Higher CA level and lower EDTA level could trigger the synthesis of ascorbic acid and higher level of EDTA could trigger the synthesis of glutathione. CA and EDTA could promote Pb accumulation of I. lactea var. chinensis and Pb concentration in the leaves and roots at 2 mmol/kg EDTA treatment increased significantly and reached to 160.44 and 936.08 μg/g DW, respectively, and 1.8 and 1.6 times higher than those of the control. The results indicated that I. lactea var. chinensis could be used to remediate Pb tailing and the role of EDTA in promoting Pb accumulation was better than CA did.

  7. Leaf Abscission Induced by Ethylene in Water-Stressed Intact Seedlings of Cleopatra Mandarin Requires Previous Abscisic Acid Accumulation in Roots.

    PubMed

    Gomez-Cadenas, A.; Tadeo, F. R.; Talon, M.; Primo-Millo, E.

    1996-09-01

    The involvement of abscisic acid (ABA) in the process of leaf abscission induced by 1-aminocyclopropane-1-carboxylic acid (ACC) transported from roots to shoots in Cleopatra mandarin (Citrus reshni Hort. ex Tan.) seedlings grown under water stress was studied using norflurazon (NF). Water stress induced both ABA (24-fold) and ACC (16-fold) accumulation in roots and arrested xylem flow. Leaf bulk ABA also increased (8-fold), although leaf abscission did not occur. Shortly after rehydration, root ABA and ACC returned to their prestress levels, whereas sharp and transitory increases of ACC (17-fold) and ethylene (10-fold) in leaves and high percentages of abscission (up to 47%) were observed. NF suppressed the ABA and ACC accumulation induced by water stress in roots and the sharp increases of ACC and ethylene observed after rewatering in leaves. NF also reduced leaf abscission (7-10%). These results indicate that water stress induces root ABA accumulation and that this is required for the process of leaf abscission to occur. It was also shown that exogenous ABA increases ACC levels in roots but not in leaves. Collectively, the data suggest that ABA, the primary sensitive signal to water stress, modulates the levels of ethylene, which is the hormonal activator of leaf abscission. This assumption implies that root ACC levels are correlated with root ABA amounts in a dependent way, which eventually links water status to an adequate, protective response such as leaf abscission.

  8. meso-Dihydroguaiaretic acid inhibits hepatic lipid accumulation by activating AMP-activated protein kinase in human HepG2 cells.

    PubMed

    Lee, Myoung-Su; Kim, Kyung Jin; Kim, Daeyoung; Lee, Kyung-Eun; Hwang, Jae-Kwan

    2011-01-01

    Hepatic lipid accumulation is a major risk factor for dyslipidemia, nonalcoholic fatty liver disease, and insulin resistance. The present study was conducted to evaluate hypolipidemic effects of meso-dihydroguaiaretic acid (MDA), anti-oxidative and anti-inflammatory compound isolated from the Myristica fragrans HOUTT., by oil red O staining, reverse transcription-polymerase chain reaction (RT-PCR), and Western blot. MDA significantly inhibited insulin-induced hepatic lipid accumulation in a dose-dependent manner. The lipid-lowering effect of MDA was accompanied by increased expression of proteins involved in fatty acid oxidation and decreased expression of lipid synthetic proteins. In addition, MDA activated AMP-activated protein kinase (AMPK) as determined by phosphorylation of acetyl-CoA carboxylase (ACC), a downstream target of AMPK. The effects of MDA on lipogenic protein expression were suppressed by pretreatment with compound C, an AMPK inhibitor. Taken together, these findings show that MDA inhibits insulin-induced lipid accumulation in human HepG2 cells by suppressing expression of lipogenic proteins through AMPK signaling, suggesting a potent lipid-lowering agent.

  9. The potato suberin feruloyl transferase FHT which accumulates in the phellogen is induced by wounding and regulated by abscisic and salicylic acids

    PubMed Central

    Soler, Marçal; Molinas, Marisa; Figueras, Mercè

    2013-01-01

    The present study provides new insights on the role of the potato (Solanum tuberosum) suberin feruloyl transferase FHT in native and wound tissues, leading to conclusions about hitherto unknown properties of the phellogen. In agreement with the enzymatic role of FHT, it is shown that its transcriptional activation and protein accumulation are specific to tissues that undergo suberization such as the root boundary layers of the exodermis and the endodermis, along with the tuber periderm. Remarkably, FHT expression and protein accumulation within the periderm is restricted to the phellogen derivative cells with phellem identity. FHT levels in the periderm are at their peak near harvest during periderm maturation, with the phellogen becoming meristematically inactive and declining thereafter. However, periderm FHT levels remain high for several months after harvest, suggesting that the inactive phellogen retains the capacity to synthesize ferulate esters. Tissue wounding induces FHT expression and the protein accumulates from the first stages of the healing process onwards. FHT is up-regulated by abscisic acid and down-regulated by salicylic acid, emphasizing the complex regulation of suberin synthesis and wound healing. These findings open up new prospects important for the clarification of the suberization process and yield important information with regard to the skin quality of potatoes. PMID:23918964

  10. The potato suberin feruloyl transferase FHT which accumulates in the phellogen is induced by wounding and regulated by abscisic and salicylic acids.

    PubMed

    Boher, Pau; Serra, Olga; Soler, Marçal; Molinas, Marisa; Figueras, Mercè

    2013-08-01

    The present study provides new insights on the role of the potato (Solanum tuberosum) suberin feruloyl transferase FHT in native and wound tissues, leading to conclusions about hitherto unknown properties of the phellogen. In agreement with the enzymatic role of FHT, it is shown that its transcriptional activation and protein accumulation are specific to tissues that undergo suberization such as the root boundary layers of the exodermis and the endodermis, along with the tuber periderm. Remarkably, FHT expression and protein accumulation within the periderm is restricted to the phellogen derivative cells with phellem identity. FHT levels in the periderm are at their peak near harvest during periderm maturation, with the phellogen becoming meristematically inactive and declining thereafter. However, periderm FHT levels remain high for several months after harvest, suggesting that the inactive phellogen retains the capacity to synthesize ferulate esters. Tissue wounding induces FHT expression and the protein accumulates from the first stages of the healing process onwards. FHT is up-regulated by abscisic acid and down-regulated by salicylic acid, emphasizing the complex regulation of suberin synthesis and wound healing. These findings open up new prospects important for the clarification of the suberization process and yield important information with regard to the skin quality of potatoes.

  11. Metabolomics Analysis and Biosynthesis of Rosmarinic Acid in Agastache rugosa Kuntze Treated with Methyl Jasmonate

    PubMed Central

    Uddin, Md. Romij; Xu, Hui; Park, Woo Tae; Tuan, Pham Anh; Li, Xiaohua; Chung, Eunsook; Lee, Jai-Heon; Park, Sang Un

    2013-01-01

    This study investigated the effect of methyl jasmonate (MeJA) on metabolic profiles and rosmarinic acid (RA) biosynthesis in cell cultures of Agastache rugosa Kuntze. Transcript levels of phenylpropanoid biosynthetic genes, i.e., ArPAL, Ar4CL, and ArC4H, maximally increased 4.5-fold, 3.4-fold, and 3.5-fold, respectively, compared with the untreated controls, and the culture contained relatively high amounts of RA after exposure of cells to 50 µM MeJA. RA levels were 2.1-, 4.7-, and 3.9-fold higher after exposure to 10, 50, and 100 µM MeJA, respectively, than those in untreated controls. In addition, the transcript levels of genes attained maximum levels at different time points after the initial exposure. The transcript levels of ArC4H and Ar4CL were transiently induced by MeJA, and reached a maximum of up to 8-fold at 3 hr and 6 hr, respectively. The relationships between primary metabolites and phenolic acids in cell cultures of A. rugosa treated with MeJA were analyzed by gas chromatography coupled with time-of-flight mass spectrometry. In total, 45 metabolites, including 41 primary metabolites and 4 phenolic acids, were identified from A. rugosa. Metabolite profiles were subjected to partial least square-discriminate analysis to evaluate the effects of MeJA. The results indicate that both phenolic acids and precursors for the phenylpropanoid biosynthetic pathway, such as aromatic amino acids and shikimate, were induced as a response to MeJA treatment. Therefore, MeJA appears to have an important impact on RA accumulation, and the increased RA accumulation in the treated cells might be due to activation of the phenylpropanoid genes ArPAL, ArC4H, and Ar4CL. PMID:23724034

  12. Accumulate-Repeat-Accumulate-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel; Thorpe, Jeremy

    2007-01-01

    Accumulate-repeat-accumulate-accumulate (ARAA) codes have been proposed, inspired by the recently proposed accumulate-repeat-accumulate (ARA) codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. ARAA codes can be regarded as serial turbolike codes or as a subclass of low-density parity-check (LDPC) codes, and, like ARA codes they have projected graph or protograph representations; these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The objective in proposing ARAA codes as a subclass of ARA codes was to enhance the error-floor performance of ARA codes while maintaining simple encoding structures and low maximum variable node degree.

  13. The low phytic acid1-241 (lpa1-241) maize mutation alters the accumulation of anthocyanin pigment in the kernel.

    PubMed

    Badone, Francesco Cerino; Cassani, Elena; Landoni, Michela; Doria, Enrico; Panzeri, Dario; Lago, Chiara; Mesiti, Francesca; Nielsen, Erik; Pilu, Roberto

    2010-04-01

    The lpa1 mutations in maize are caused by lesions in the ZmMRP4 (multidrug resistance-associated proteins 4) gene. In previous studies (Raboy et al. in Plant Physiol 124:355-368, 2000; Pilu et al. in Theor Appl Genet 107:980-987, 2003a; Shi et al. Nat Biotechnol 25:930-937, 2007), several mutations have been isolated in this locus causing a reduction of phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate, or InsP(6)) content and an equivalent increasing of free phosphate. In particular, the lpa1-241 mutation causes a reduction of up to 90% of phytic acid, associated with strong pleiotropic effects on the whole plant. In this work, we show, for the first time to our knowledge, an interaction between the accumulation of anthocyanin pigments in the kernel and the lpa mutations. In fact the lpa1-241 mutant accumulates a higher level of anthocyanins as compared to wild type either in the embryo (about 3.8-fold) or in the aleurone layer (about 0.3-fold) in a genotype able to accumulate anthocyanin. Furthermore, we demonstrate that these pigments are mislocalised in the cytoplasm, conferring a blue pigmentation of the scutellum, because of the neutral/basic pH of this cellular compartment. As a matter of fact, the propionate treatment, causing a specific acidification of the cytoplasm, restored the red pigmentation of the scutellum in the mutant and expression analysis showed a reduction of ZmMRP3 anthocyanins' transporter gene expression. On the whole, these data strongly suggest a possible interaction between the lpa mutation and anthocyanin accumulation and compartmentalisation in the kernel.

  14. Mutations in the Hyperosmotic Stress-Responsive Mitochondrial BASIC AMINO ACID CARRIER2 Enhance Proline Accumulation in Arabidopsis1[C][W

    PubMed Central

    Toka, Iman; Planchais, Séverine; Cabassa, Cécile; Justin, Anne-Marie; De Vos, Delphine; Richard, Luc; Savouré, Arnould; Carol, Pierre

    2010-01-01

    Mitochondrial carrier family proteins are diverse in their substrate specificity, organellar location, and gene expression. In Arabidopsis (Arabidopsis thaliana), 58 genes encode these six-transmembrane-domain proteins. We investigated the biological role of the basic amino acid carrier Basic Amino Acid Carrier2 (BAC2) from Arabidopsis that is structurally and functionally similar to ARG11, a yeast ornithine and arginine carrier, and to Arabidopsis BAC1. By studying the expression of BAC2 and the consequences of its mutation in Arabidopsis, we showed that BAC2 is a genuine mitochondrial protein and that Arabidopsis requires expression of the BAC2 gene in order to use arginine. The BAC2 gene is induced by hyperosmotic stress (with either 0.2 m NaCl or 0.4 m mannitol) and dark-induced senescence. The BAC2 promoter contains numerous stress-related cis-regulatory elements, and the transcriptional activity of BAC2:β-glucuronidase is up-regulated by stress and senescence. Under hyperosmotic stress, bac2 mutants express the P5CS1 proline biosynthetic gene more strongly than the wild type, and this correlates with a greater accumulation of Pro. Our data suggest that BAC2 is a hyperosmotic stress-inducible transporter of basic amino acids that contributes to proline accumulation in response to hyperosmotic stress in Arabidopsis. PMID:20172963

  15. High Temperature Induces Expression of Tobacco Transcription Factor NtMYC2a to Regulate Nicotine and JA Biosynthesis

    PubMed Central

    Yang, Liming; Li, Junying; Ji, Jianhui; Li, Ping; Yu, Liangliang; Abd_Allah, Elsayed F.; Luo, Yuming; Hu, Liwei; Hu, Xiangyang

    2016-01-01

    Environmental stress elevates the level of jasmonic acid (JA) and activates the biosynthesis of nicotine and related pyridine alkaloids in tobacco (Nicotiana tabacum L.) by up-regulating the expression of putrescine N-methyltransferase 1 (NtPMT1), which encodes a putrescine N-methyl transferase that catalyzes nicotine formation. The JA signal suppressor JASMONATE ZIM DOMAIN 1 (NtJAZ1) and its target protein, NtMYC2a, also regulate nicotine biosynthesis; however, how these proteins interact to regulate abiotic-induced nicotine biosynthesis is poorly understood. In this study, we found that high-temperature (HT) treatment activated transcription of NtMYC2a, which subsequently stimulated the transcription of genes associated with JA biosynthesis, including Lipoxygenase (LOX), Allene oxide synthase (AOS), Allene oxide cyclase (AOC), and 12-oxophytodienodate reductase (OPR). Overexpression of NtMYC2a increased nicotine biosynthesis by enhancing its binding to the promoter of NtPMT1. Overexpression of either NtJAZ1 or proteasome-resistant NtJAZ1ΔC suppressed nicotine production under normal conditions, but overexpression only of the former resulted in low levels of nicotine under HT treatment. These data suggest that HT induces NtMYC2a accumulation through increased transcription to activate nicotine synthesis; meanwhile, HT-induced NtMYC2a can activate JA synthesis to promote additional NtMYC2a activity by degrading NtJAZ1 at the post-transcriptional level. PMID:27833561

  16. Local root abscisic acid (ABA) accumulation depends on the spatial distribution of soil moisture in potato: implications for ABA signalling under heterogeneous soil drying

    PubMed Central

    Puértolas, Jaime; Conesa, María R.; Ballester, Carlos; Dodd, Ian C.

    2015-01-01

    Patterns of root abscisic acid (ABA) accumulation ([ABA]root), root water potential (Ψroot), and root water uptake (RWU), and their impact on xylem sap ABA concentration ([X-ABA]) were measured under vertical partial root-zone drying (VPRD, upper compartment dry, lower compartment wet) and horizontal partial root-zone drying (HPRD, two lateral compartments: one dry, the other wet) of potato (Solanum tuberosum L.). When water was withheld from the dry compartment for 0–10 d, RWU and Ψroot were similarly lower in the dry compartment when soil volumetric water content dropped below 0.22cm3 cm–3 for both spatial distributions of soil moisture. However, [ABA]root increased in response to decreasing Ψroot in the dry compartment only for HPRD, resulting in much higher ABA accumulation than in VPRD. The position of the sampled roots (~4cm closer to the surface in the dry compartment of VPRD than in HPRD) might account for this difference, since older (upper) roots may accumulate less ABA in response to decreased Ψroot than younger (deeper) roots. This would explain differences in root ABA accumulation patterns under vertical and horizontal soil moisture gradients reported in the literature. In our experiment, these differences in root ABA accumulation did not influence [X-ABA], since the RWU fraction (and thus ABA export to shoots) from the dry compartment dramatically decreased simultaneously with any increase in [ABA]root. Thus, HPRD might better trigger a long-distance ABA signal than VPRD under conditions allowing simultaneous high [ABA]root and relatively high RWU fraction. PMID:25547916

  17. Local root abscisic acid (ABA) accumulation depends on the spatial distribution of soil moisture in potato: implications for ABA signalling under heterogeneous soil drying.

    PubMed

    Puértolas, Jaime; Conesa, María R; Ballester, Carlos; Dodd, Ian C

    2015-04-01

    Patterns of root abscisic acid (ABA) accumulation ([ABA]root), root water potential (Ψroot), and root water uptake (RWU), and their impact on xylem sap ABA concentration ([X-ABA]) were measured under vertical partial root-zone drying (VPRD, upper compartment dry, lower compartment wet) and horizontal partial root-zone drying (HPRD, two lateral compartments: one dry, the other wet) of potato (Solanum tuberosum L.). When water was withheld from the dry compartment for 0-10 d, RWU and Ψroot were similarly lower in the dry compartment when soil volumetric water content dropped below 0.22cm(3) cm(-3) for both spatial distributions of soil moisture. However, [ABA]root increased in response to decreasing Ψroot in the dry compartment only for HPRD, resulting in much higher ABA accumulation than in VPRD. The position of the sampled roots (~4cm closer to the surface in the dry compartment of VPRD than in HPRD) might account for this difference, since older (upper) roots may accumulate less ABA in response to decreased Ψroot than younger (deeper) roots. This would explain differences in root ABA accumulation patterns under vertical and horizontal soil moisture gradients reported in the literature. In our experiment, these differences in root ABA accumulation did not influence [X-ABA], since the RWU fraction (and thus ABA export to shoots) from the dry compartment dramatically decreased simultaneously with any increase in [ABA]root. Thus, HPRD might better trigger a long-distance ABA signal than VPRD under conditions allowing simultaneous high [ABA]root and relatively high RWU fraction.

  18. Induced Protoporphyrin IX Accumulation by the δ-Aminolevulinic Acid in Bacteria and its Potential Use in the Photodynamic Therapy

    NASA Astrophysics Data System (ADS)

    Brígido-Aparicio, Cyntiha; Ramón-Gallegos, Eva; Arenas-Huertero, Francisco Jesús; Uribe-Hernández, Raúl

    2008-08-01

    The increasing incident of resistant strains to antibiotic has encouraged the search of new antibacterial treatments, such as the photodynamic therapy. In recent years, photodynamic therapy has demonstrated being a good technology for the treatment of recurrent bacteria infection. PDT presents a hopeful approach to eliminate Gram positive and negative bacteria in immunological compromised patients. This therapy uses a laser in combination with a photosensibilizer in presence of intracellular molecular oxygen. The process generates an effect of phototoxicity in bacterial cells. The aim of this work was to determine the in vitro conditions to accumulate PpIX in effective concentrations in Staphylococcus aureus ATCC25923 and Streptococcus pyogenes, which are responsible of human cutaneous diseases. A cellular suspension of both strains was prepared in TSB to obtain growth in Log-phase, then, the suspensions were adjusted to a final concentration of 2.61×108 cells/mL. The strains were exposed to increasing concentrations from 0 to 160μg/mL of δ-ALA in order to determinate the concentration that induces the biggest accumulation of PpIX. PpIX was measured using the Piomelli method modified for bacteria. The concentration selected was 40 mg/mL of ALA. It was found that in basal concentration of δ-ALA (0 μg/mL) both strains accumulated similar amount of PpIX. In concentrations of 5 mg/mL of δ-ALA it was observed a significant (p<0.001) increment in PpIX concentration. Finally it was realized a kinetic to determinate the optimal accumulation over the time at 0, 5, 10, 15 and 30 min, and 1, 2, 4, 8, 16 and 32 h. It was found that the ideal time for PDT application, in both strains, was 24 h because in smaller times there was not statistically significant difference. The S. aureus ATCC25923 accumulated significantly the biggest concentration of PpIX with regard to S. pyogenes. In conclusion, it was found that the optimal conditions to apply PDT will be to expose both

  19. Increased placental fatty acid transporter 6 and binding protein 3 expression and fetal liver lipid accumulation in a mouse model of obesity in pregnancy.

    PubMed

    Díaz, Paula; Harris, Jessica; Rosario, Fredrick J; Powell, Theresa L; Jansson, Thomas

    2015-12-15

    Obesity in pregnancy is associated with increased fetal growth and adiposity, which, in part, is determined by transplacental nutrient supply. Trophoblast uptake and intracellular trafficking of lipids are dependent on placental fatty acid transport proteins (FATP), translocase (FAT/CD36), and fatty acid binding proteins (FABP). We hypothesized that maternal obesity in mice leads to increased placental expression of FAT/CD36, FATPs, and FABPs, and lipid accumulation in the fetal liver. C57/BL6J female mice were fed either a control (C; n = 10) or an obesogenic (OB; n = 10) high-fat, high-sugar diet before mating and throughout pregnancy. At E18.5, placentas and fetal livers were collected. Trophoblast plasma membranes (TPM) were isolated from placental homogenates. Expression of FAT/CD36 and FATP (TPM) and FABP (homogenates) was determined by immunoblotting. Gene expression was assessed by RT-quantitative PCR. Sections of fetal livers were stained for Oil Red O, and lipid droplets were quantified. TPM protein expression of FAT/CD36, FATP 2, and FATP 4 was comparable between C and OB groups. Conversely, TPM FATP 6 expression was increased by 35% in OB compared with C placentas without changes in mRNA expression. FABPs 1, 3-5 and PPARγ were expressed in homogenates, and FABP 3 expression increased 27% in OB compared with C placentas; however, no changes were observed in mRNA expression. Lipid droplet accumulation was 10-fold higher in the livers of fetuses from OB compared with C group. We propose that increased lipid transport capacity in obese mice promotes transplacental fatty acid transport and contributes to excess lipid accumulation in the fetal liver.

  20. Endoplasmic reticulum-localized small heat shock protein that accumulates in mulberry tree (Morus bombycis Koidz.) during seasonal cold acclimation is responsive to abscisic acid.

    PubMed

    Ukaji, Norifumi; Kuwabara, Chikako; Kanno, Yuri; Seo, Mitsunori; Takezawa, Daisuke; Arakawa, Keita; Fujikawa, Seizo

    2010-04-01

    With seasonal changes, several proteins accumulate in the endoplasmic reticulum (ER)-enriched fraction in the bark of mulberry tree (Morus bombycis Koidz.). Results of partial amino acid sequence analysis in our previous study suggested that one of these proteins is the ER-localized small heat shock protein (sHSP), designated 20-kD winter-accumulating protein (WAP20). In the present study, molecular and biochemical properties of WAP20 were investigated in detail. The deduced amino acid sequence of the cDNA has the predicted signal sequence to the ER, retention signal to the ER and two consensus regions conserved in sHSPs. Recombinant WAP20 expressed in Escherichia coli also showed typical biochemical features of sHSPs, including the formation of a high-molecular-mass complex between 200 and 300 kD under native conditions, promotion of the renaturation of chemically denaturated citrate synthase and prevention of heat stress-induced aggregation of the enzyme. Transcript levels of WAP20 in the bark tissue were seasonally changed, showing high expression levels from mid-October to mid-December, and the transcript levels were additionally increased and decreased by cold treatment and warm treatment, respectively. WAP20 transcripts were detected abundantly in bark tissue rather than xylem and winter bud tissues during seasonal cold acclimation. The bark tissue specificity of WAP20 accumulation was also observed by exogenous application of phytohormone abscisic acid (ABA) in de-acclimated twigs, whereas WAP20 transcripts were increased in all of these tissues by heat shock treatment at 37 degrees C in summer twigs. The results suggest that ABA may be involved in the expression of the WAP20 gene in bark tissue of the mulberry tree during seasonal cold acclimation.

  1. Folic acid deficiency enhances abeta accumulation in APP/PS1 mice brain and decreases amyloid-associated miRNAs expression.

    PubMed

    Liu, Huan; Tian, Tian; Qin, Shanchun; Li, Wen; Zhang, Xumei; Wang, Xuan; Gao, Yuxia; Huang, Guowei

    2015-12-01

    Recent efforts have revealed the microRNA (miRNA) pathways in the pathogenesis of Alzheimer's disease (AD). Epidemiological studies have revealed an association between folic acid deficiency and AD risk. However, the effects of folic acid deficiency on miRNA expression in AD animals have not been observed. We aimed to find if folic acid deficiency may enhance amyloid-β (Aβ) peptide deposition and regulate amyloid-associated miRNAs and their target genes expression in APP/PS1 mice. APP/PS1 mice and N2a cells were treated with folic acid-deficient diet or medium. Cognitive function of mice was assessed using the Morris water maze. miRNA profile was tested by polymerase chain reaction (PCR) array. Different expressional miRNAs were validated by real-time PCR. The deposition of Aβ plaques was evaluated by immunohistochemistry and enzyme-linked immunosorbent assay. APP and BACE1 proteins in mice brain and N2a cells were determined by Western blot. Folic acid deficiency aggravated amyloid pathology in AD mice. The AD+FD group showed shorter time spent in the target zone during the probe test. Analysis of miRNAs predicted to target these genes revealed several miRNA candidates that were differentially modulated by folic acid deficiency. In APP/PS1 mice brains and N2a cells with folic acid-deficient treatment, miR-106a-5p, miR-200b-3p and miR-339-5p were down-regulated, and their target genes APP and BACE1 were up-regulated. In conclusion, folic acid deficiency can enhance Aβ accumulation in APP/PS1 mice brain and decrease amyloid-associated miRNAs expression.

  2. High temperature stimulates acetic acid accumulation and enhances the growth inhibition and ethanol production by Saccharomyces cerevisiae under fermenting conditions.

    PubMed

    Woo, Ji-Min; Yang, Kyung-Mi; Kim, Sae-Um; Blank, Lars M; Park, Jin-Byung

    2014-07-01

    Cellular responses of Saccharomyces cerevisiae to high temperatures of up to 42 °C during ethanol fermentation at a high glucose concentration (i.e., 100 g/L) were investigated. Increased temperature correlated with stimulated glucose uptake to produce not only the thermal protectant glycerol but also ethanol and acetic acid. Carbon flux into the tricarboxylic acid (TCA) cycle correlated positively with cultivation temperature. These results indicate that the increased demand for energy (in the form of ATP), most likely caused by multiple stressors, including heat, acetic acid, and ethanol, was matched by both the fermentation and respiration pathways. Notably, acetic acid production was substantially stimulated compared to that of other metabolites during growth at increased temperature. The acetic acid produced in addition to ethanol seemed to subsequently result in adverse effects, leading to increased production of reactive oxygen species. This, in turn, appeared to cause the specific growth rate, and glucose uptake rate reduced leading to a decrease of the specific ethanol production rate far before glucose depletion. These results suggest that adverse effects from heat, acetic acid, ethanol, and oxidative stressors are synergistic, resulting in a decrease of the specific growth rate and ethanol production rate and, hence, are major determinants of cell stability and ethanol fermentation performance of S. cerevisiae at high temperatures. The results are discussed in the context of possible applications.

  3. Rice bran oil and oryzanol reduce plasma lipid and lipoprotein cholesterol concentrations and aortic cholesterol ester accumulation to a greater extent than ferulic acid in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Woolfrey, Benjamin; Kritchevsky, David

    2007-02-01

    plasma triglyceride concentrations compared to the control (-53% and -65%, respectively) and ferulic acid (-47% and -60%, respectively) diets. Hamsters fed the control and ferulic acid diets had significantly higher plasma vitamin E concentrations compared to the RBO (201% and 161%, respectively) and oryzanol (548% and 462%, respectively) diets; the ferulic acid and oryzanol diets had significantly lower plasma lipid hydroperoxide levels than the control (-57% and -46%, respectively) diet. The oryzanol-fed hamsters excreted significantly more coprostenol and cholesterol in their feces than the ferulic acid (127% and 120%, respectively) diet. The control diet had significantly greater aortic TC and FC accumulation compared to the RBO (115% and 89%, respectively), ferulic acid (48% and 58%, respectively) and the oryzanol (74% and 70%, respectively) diets. However, only the RBO and oryzanol diets had significantly lower aortic cholesterol ester accumulation compared to the control (-73% and -46%, respectively) diet. The present study suggests that at equal dietary levels, oryzanol has a greater effect on lowering plasma non-HDL-C levels and raising plasma HDL-C than ferulic acid, possibly through a greater extent to increase fecal excretion of cholesterol and its metabolites. However, ferulic acid may have a greater antioxidant capacity via its ability to maintain serum vitamin E levels compared to RBO and oryzanol. Thus, both oryzanol and ferulic acid may exert similar antiatherogenic properties, but through different mechanisms.

  4. Perennial peanut (Arachis glabrata Benth.) leaves contain hydroxycinnamoyl-CoA:tartaric acid hydroxycinnamoyl transferase activity and accumulate hydroxycinnamoyl-tartaric acid esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many plants accumulate hydroxycinnamoyl esters to protect against abiotic and biotic stresses. Caffeoyl esters, in particular, can be substrates for endogenous polyphenol oxidases (PPOs). Recently, we showed that perennial peanut (Arachis glabrata Benth.) leaves contain PPO and identified one PPO su...

  5. Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm.

    PubMed

    Harholt, Jesper; Bach, Inga C; Lind-Bouquin, Solveig; Nunan, Kylie J; Madrid, Susan M; Brinch-Pedersen, Henrik; Holm, Preben B; Scheller, Henrik V

    2010-04-01

    Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm-specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal (Lys-Asp-Glu-Leu) KDEL were used. Transgenic plants were recovered in all four cases but no qualitative differences could be observed whether KDEL was added or not. Endo-xylanase activity in transgenic grains was increased between two and threefold relative to wild type. The grains were shrivelled and had a 25%-33% decrease in mass. Extensive analysis of the cell walls showed a 10%-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water-extractable arabinoxylan, and a shift in the MW of the water-extractable arabinoxylan from being mainly larger than 85 kD to being between 2 and 85 kD. Ferulic acid esterase-expressing grains were also shrivelled, and the seed weight was decreased by 20%-50%. No ferulic acid esterase activity could be detected in wild-type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15%-40% increase in water-unextractable arabinoxylan and a decrease in monomeric ferulic acid between 13% and 34%. In all the plants, the observed changes are consistent with a plant response that serves to minimize the effect of the heterologously expressed enzymes by increasing arabinoxylan biosynthesis and cross-linking.

  6. Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm

    SciTech Connect

    Harholt, Jesper; Bach, Inga C; Lind-Bouquin, Solveig; Nunan, Kylie J.; Madrid, Susan M.; Brinch-Pedersen, Henrik; Holm, Preben B.; Scheller, Henrik V.

    2009-12-08

    Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal KDEL were used. Transgenic plants were recovered in all four cases but no qualitative differences could be observed whether KDEL was added or not. Endo-xylanase activity in transgenic grains was increased between two and three fold relative to wild type. The grains were shriveled and had a 25-33% decrease in mass. Extensive analysis of the cell walls showed a 10-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water extractable arabinoxylan, and a shift in the MW of the water extractable arabinoxylan from being mainly larger than 85 kD to being between 2 kD and 85 kD. Ferulic acid esterase expressing grains were also shriveled and the seed weight was decreased by 20-50%. No ferulic acid esterase activity could be detected in wild type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15-40% increase in water unextractable arabinoxylan and a decrease in monomeric ferulic acid between 13 and 34%. In all the plants the observed changes are consistent with a plant response that serves to minimize the effect of the heterologously expressed enzymes by increasing arabinoxylan biosynthesis and cross-linking.

  7. Regulation of basal and oxidative stress-triggered jasmonic acid-related gene expression by glutathione.

    PubMed

    Han, Yi; Mhamdi, Amna; Chaouch, Sejir; Noctor, Graham

    2013-06-01

    Glutathione is a determinant of cellular redox state with roles in defence and detoxification. Emerging concepts suggest that this compound also has functions in cellular signalling. Here, we report evidence that glutathione plays potentially important roles in setting signalling strength through the jasmonic acid (JA) pathway. Firstly, we show that basal expression of JA-related genes is correlated with leaf glutathione content when the latter is manipulated either genetically or pharmacologically. Secondly, analyses of an oxidative stress signalling mutant, cat2, reveal that up-regulation of the JA pathway triggered by intracellular oxidation requires accompanying glutathione accumulation. Genetically blocking this accumulation in a cat2 cad2 line largely annuls H2 O2 -induced expression of JA-linked genes, and this effect can be rescued by exogenously supplying glutathione. While most attention on glutathione functions in biotic stress responses has been focused on the thiol-regulated protein NPR1, a comparison of JA-linked gene expression in cat2 cad2 and cat2 npr1 double mutants provides evidence that glutathione acts through other components to regulate the response of this pathway to oxidative stress. Our study provides new information implicating glutathione as a factor determining basal JA gene expression and suggests novel glutathione-dependent control points that regulate JA signalling in response to intracellular oxidation.

  8. Effects of tung oilseed FAD2 and DGAT2 genes on unsaturated fatty acid accumulation in Rhodotorula glutinis and Arabidopsis thaliana.

    PubMed

    Chen, Yicun; Cui, Qinqin; Xu, Yongjie; Yang, Susu; Gao, Ming; Wang, Yangdong

    2015-08-01

    Genetic engineering to produce valuable lipids containing unsaturated fatty acids (UFAs) holds great promise for food and industrial applications. Efforts to genetically modify plants to produce desirable UFAs with single enzymes, however, have had modest success. The key enzymes fatty acid desaturase (FAD) and diacylglycerol acyltransferase (DGAT) are responsible for UFA biosynthesis (a push process) and assembling fatty acids into lipids (a pull process) in plants, respectively. To examine their roles in UFA accumulation, VfFAD2 and VfDGAT2 genes cloned from Vernicia fordii (tung tree) oilseeds were conjugated and transformed into Rhodotorula glutinis and Arabidopsis thaliana via Agrobacterium tumefaciens. Real-time quantitative PCR revealed variable gene expression levels in the transformants, with a much higher level of VfDGAT2 than VfFAD2. The relationship between VfFAD2 expression and linoleic acid (C18:2) increases in R. glutinis (R (2) = 0.98) and A. thaliana (R (2) = 0.857) transformants was statistically linear. The VfDGAT2 expression level was statistically correlated with increased total fatty acid content in R. glutinis (R (2) = 0.962) and A. thaliana (R (2) = 0.8157) transformants. With a similar expression level between single- and two-gene transformants, VfFAD2-VfDGAT2 co-transformants showed a higher linolenic acid (C18:3) yield in R. glutinis (174.36 % increase) and A. thaliana (14.61 % increase), and eicosatrienoic acid (C20:3) was enriched (17.10 % increase) in A. thaliana. Our data suggest that VfFAD2-VfDGAT2 had a synergistic effect on UFA metabolism in R. glutinis, and to a lesser extent, A. thaliana. These results show promise for further genetic engineering of plant lipids to produce desirable UFAs.

  9. Accumulated SET protein up-regulates and interacts with hnRNPK, increasing its binding to nucleic acids, the Bcl-xS repression, and cellular proliferation.

    PubMed

    Almeida, Luciana O; Garcia, Cristiana B; Matos-Silva, Flavia A; Curti, Carlos; Leopoldino, Andréia M

    2014-02-28

    SET and hnRNPK are proteins involved in gene expression and regulation of cellular signaling. We previously demonstrated that SET accumulates in head and neck squamous cell carcinoma (HNSCC); hnRNPK is a prognostic marker in cancer. Here, we postulate that SET and hnRNPK proteins interact to promote tumorigenesis. We performed studies in HEK293 and HNSCC (HN6, HN12, and HN13) cell lines with SET/hnRNPK overexpression and knockdown, respectively. We found that SET and/or hnRNPK protein accumulation increased cellular proliferation. SET accumulation up-regulated hnRNPK mRNA and total/phosphorylated protein, promoted hnRNPK nuclear location, and reduced Bcl-x mRNA levels. SET protein directly interacted with hnRNPK, increasing both its binding to nucleic acids and Bcl-xS repression. We propose that hnRNPK should be a new target of SET and that SET-hnRNPK interaction, in turn, has potential implications in cell survival and malignant transformation.

  10. Elevated acetyl-CoA by amino acid recycling fuels microalgal neutral lipid accumulation in exponential growth phase for biofuel production.

    PubMed

    Yao, Lina; Shen, Hui; Wang, Nan; Tatlay, Jaspaul; Li, Liang; Tan, Tin Wee; Lee, Yuan Kun

    2017-04-01

    Microalgal neutral lipids [mainly in the form of triacylglycerols (TAGs)], feasible substrates for biofuel, are typically accumulated during the stationary growth phase. To make microalgal biofuels economically competitive with fossil fuels, generating strains that trigger TAG accumulation from the exponential growth phase is a promising biological approach. The regulatory mechanisms to trigger TAG accumulation from the exponential growth phase (TAEP) are important to be uncovered for advancing economic feasibility. Through the inhibition of pyruvate dehydrogenase kinase by sodium dichloroacetate, acetyl-CoA level increased, resulting in TAEP in microalga Dunaliella tertiolecta. We further reported refilling of acetyl-CoA pool through branched-chain amino acid catabolism contributed to an overall sixfold TAEP with marginal compromise (4%) on growth in a TAG-rich D. tertiolecta mutant from targeted screening. Herein, a three-step α loop-integrated metabolic model is introduced to shed lights on the neutral lipid regulatory mechanism. This article provides novel approaches to compress lipid production phase and heightens lipid productivity and photosynthetic carbon capture via enhancing acetyl-CoA level, which would optimize renewable microalgal biofuel to fulfil the demanding fuel market.

  11. Dual mechanisms regulating glutamate decarboxylases and accumulation of gamma-aminobutyric acid in tea (Camellia sinensis) leaves exposed to multiple stresses

    PubMed Central

    Mei, Xin; Chen, Yiyong; Zhang, Lingyun; Fu, Xiumin; Wei, Qing; Grierson, Don; Zhou, Ying; Huang, Yahui; Dong, Fang; Yang, Ziyin

    2016-01-01

    γ-Aminobutyric acid (GABA) is one of the major inhibitory neurotransmitters in the central nervous system. It has multiple positive effects on mammalian physiology and is an important bioactive component of tea (Camellia sinensis). GABA generally occurs at a very low level in plants but GABA content increases substantially after exposure to a range of stresses, especially oxygen-deficiency. During processing of tea leaves, a combination of anoxic stress and mechanical damage are essential for the high accumulation of GABA. This is believed to be initiated by a change in glutamate decarboxylase activity, but the underlying mechanisms are unclear. In the present study we characterized factors regulating the expression and activity of three tea glutamate decarboxylase genes (CsGAD1, 2, and 3), and their encoded enzymes. The results suggests that, unlike the model plant Arabidopsis thaliana, there are dual mechanisms regulating the accumulation of GABA in tea leaves exposed to multiple stresses, including activation of CsGAD1 enzymatic activity by calmodulin upon the onset of the stress and accumulation of high levels of CsGAD2 mRNA induced by a combination of anoxic stress and mechanical damage. PMID:27021285

  12. Impacts of rapeseed dregs on Cd availability in contaminated acid soil and Cd translocation and accumulation in rice plants.

    PubMed

    Yang, Wen-Tao; Gu, Jiao-Feng; Zou, Jia-Ling; Zhou, Hang; Zeng, Qing-Ru; Liao, Bo-Han

    2016-10-01

    The objective of the present study was to investigate the effects of rapeseed dregs (RSD, a commonly organic fertilizer in rural China) at application rates of 0, 0.75, 1.5, and 3.0 % on Cd availability in soil and its accumulation in rice plants (Oryza sativa L., Xiangwanxian 12(#), and Weiyou 46(#)) by means of a pot experiment. The results showed that application of RSD resulted in a sharp decrease in the soil TCLP-extractable Cd content. However, the soil TCLP-extractable Cd content in amended soil gradually increased during the rice growing period. Application of RSD significantly increased Cd transport from root to shoot and the amount of Cd accumulated in the aerial part. RSD was an effective organic additive for increasing rice grain yield, but total Cd content in rice grain was also increased. At an application rate of 1.5-3.0 % RSD, the total Cd content in Weiyou 46(#) brown rice was 0.27-0.31 mg kg(-1), which exceeded the standard safe limit (0.2 mg kg(-1)) and was also higher than that of Xiangwanxian 12(#) (0.04-0.14 mg kg(-1)). Therefore, Weiyou 46(#) had a higher dietary risk than Xiangwanxian 12(#) with RSD application. We do not recommend planting Weiyou 46(#) and applying more than 0.75 % RSD in Cd-contaminated paddy fields.

  13. Accumulation of Glycoconjugates of 3-Methyl-4-hydroxyoctanoic Acid in Fruits, Leaves, and Shoots of Vitis vinifera cv. Monastrell following Foliar Applications of Oak Extract or Oak Lactone.

    PubMed

    Pardo-Garcia, Ana I; Wilkinson, Kerry L; Culbert, Julie A; Lloyd, Natoiya D R; Alonso, Gonzalo L; Salinas, M Rosario

    2015-05-13

    Grapevines are capable of absorbing volatile compounds present in the vineyard during the growing season, and in some cases, volatiles have been found to accumulate in fruits or leaves in glycoconjugate forms, that is, with one or more sugar moieties attached. The presence of oak lactone in wine is usually attributable to oak maturation, but oak lactone has been detected in wines made with fruit from grapevines treated with oak extract or oak lactone. This study investigated the accumulation of glycoconjugates of 3-methyl-4-hydroxyoctanoic acid (i.e., the ring-opened form of oak lactone) in the fruits, leaves, and shoots of Monastrell grapevines following foliar application of either oak extract or oak lactone at approximately 7 days postveraison. Fruits, leaves, and shoots were collected at three different time points, including at maturity. The oak lactone content of fruit was determined by gas chromatography-mass spectrometry, with declining concentrations observed in fruit from grapevines treated with oak lactone with ripening. The concentrations of a β-d-glucopyranoside of 3-methyl-4-hydroxyoctanoic acid in fruits, leaves, and shoots was determined by liquid chromatography-tandem mass spectrometry, with the highest oak lactone glucoside levels observed in leaves of grapevines treated with oak lactone. A glucose-glucose disaccharide was also tentatively identified. These results demonstrate both ring-opening and glycosylation of oak lactone occurred after experimental treatments were imposed.

  14. Comparative study of putative 9-cis-epoxycarotenoid dioxygenase and abscisic acid accumulation in the responses of Sunki mandarin and Rangpur lime to water deficit.

    PubMed

    Neves, D M; Filho, M A Coelho; Bellete, B S; Silva, M F G F; Souza, D T; Dos S Soares Filho, W; Costa, M G C; Gesteira, A S

    2013-09-01

    Abscisic acid is a plant hormone that participates in essential plant physiological processes, especially during adaptation to many environmental stresses, such as water deficit. The relationship between ABA accumulation and the expression of putative carotenoid cleavage dioxygenase (CCD) genes was investigated in the pot-cultivated leaves and roots of the 'Rangpur' lime and 'Sunki Maravilha' mandarin plants. Transpiration, stomatal resistance and leaf growth were evaluated when these genotypes were subjected to continuous water deficit. Under water deficit conditions, the 'Rangpur' lime extracts used greater amounts of water when compared to the 'Sunki Maravilha' plants, which reached the greatest stomatal resistance 5 days before 'Rangpur' lime. When subjected to water deficit, the roots and leaves of 'Sunki Maravilha' showed a progressive increase in ABA accumulation; however, in 'Rangpur' lime, alternations between high and low ABA concentrations were observed. These results suggest a retroactive feeding regulation by ABA. In 'Rangpur' lime the NCED2, NCED3 and CCD4a genes were expressed at the highest levels in the roots, and NCED5 was highly expressed in the leaves; in 'Sunki Maravilha', the NCED2 and NCED5 genes were most highly expressed in the roots, and NCED2 was most highly expressed in the leaves. However, for both genotypes, the transcription of these genes only correlated with ABA accumulation during the most severe water deficit conditions. The 'Rangpur' lime behaved as a vigorous rootstock; the leaf growth remained unaltered even when water was scarce. However, 'Sunki Maravilha' adaptation was based on the equilibrium of the response between the root and the aerial tissues due to water restriction. The use of the Sunki mandarin in combination with a scion with similar characteristics as its own, which responds to water deficit stress by accumulating ABA in the leaves, may display good drought tolerance under field conditions.

  15. Functional Analysis of Arabidopsis Mutants Points to Novel Roles for Glutathione in Coupling H2O2 to Activation of Salicylic Acid Accumulation and Signaling

    PubMed Central

    Han, Yi; Chaouch, Sejir; Mhamdi, Amna; Queval, Guillaume; Zechmann, Bernd

    2013-01-01

    Abstract Aims: Through its interaction with H2O2, glutathione is a candidate for transmission of signals in plant responses to pathogens, but identification of signaling roles is complicated by its antioxidant function. Using a genetic approach based on a conditional catalase-deficient Arabidopsis mutant, cat2, this study aimed at establishing whether GSH plays an important functional role in the transmission of signals downstream of H2O2. Results: Introducing the cad2 or allelic mutations in the glutathione synthesis pathway into cat2 blocked H2O2-triggered GSH oxidation and accumulation. While no effects on NADP(H) or ascorbate were observed, and H2O2-induced decreases in growth were maintained, blocking GSH modulation antagonized salicylic acid (SA) accumulation and SA-dependent responses. Other novel double and triple mutants were produced and compared with cat2 cad2 at the levels of phenotype, expression of marker genes, nontargeted metabolite profiling, accumulation of SA, and bacterial resistance. Most of the effects of the cad2 mutation on H2O2-triggered responses were distinct from those produced by mutations for GLUTATHIONE REDUCTASE1 (GR1) or NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), and were linked to compromised induction of ISOCHORISMATE SYNTHASE1 (ICS1) and ICS1-dependent SA accumulation. Innovation: A novel genetic approach was used in which GSH content or antioxidative capacity was independently modified in an H2O2 signaling background. Analysis of new double and triple mutants allowed us to infer previously undescribed regulatory roles for GSH. Conclusion: In parallel to its antioxidant role, GSH acts independently of NPR1 to allow increased intracellular H2O2 to activate SA signaling, a key defense response in plants. Antioxid. Redox Signal. 18, 2106–2121. PMID:23148658

  16. STUDIES ON THE DEPLETION AND ACCUMULATION OF MICROVILLI AND CHANGES IN THE TUBULOVESICULAR COMPARTMENT OF MOUSE PARIETAL CELLS IN RELATION TO GASTRIC ACID SECRETION

    PubMed Central

    Ito, S.; Schofield, G. C.

    1974-01-01

    Gastric parietal cells in mice present a spectrum of microscopic appearances due mainly to variations in the abundance of the tubular and vesicular component of the cytoplasm and in the size and number of microvilli lining the intracellular canaliculi. Differences in the range of forms among parietal cells of fasting versus fed mice were not especially striking, but cells with very numerous tubules and vesicles were more common after fasting. However, in mice treated with drugs or hormones that induce acid secretion, parietal cells were more uniform in appearance. There was a marked reduction of these cytoplasmic membranes and a concomitant increase in both the number and size of microvilli. Measurements of acid secretion in control animals and in animals treated with acid secretagogues indicated hydrogen ion secretion contemporaneous with depletion of the cytoplasmic tubulovesicular membranes and with increase of the microvilli. In mice with inhibited acid secretion, parietal cells showed an accumulation of cytoplasmic tubules and vesicles and reduction in the numbers of microvilli. Stereological methods were used to quantitate 10 different parietal cell compartments. Tracer studies with lanthanum did not reveal continuity between the tubules and the plasma membrane. However, there were regions of close apposition between the tubulovesicular membranes and the cell membrane of the canaliculus, and instances where cytoplasmic tubules extended from the cell into the core of enlarged microvilli. PMID:4138520

  17. Effect of solids retention time and temperature on waste activated sludge hydrolysis and short-chain fatty acids accumulation under alkaline conditions in continuous-flow reactors.

    PubMed

    Feng, Leiyu; Wang, Hua; Chen, Yinguang; Wang, Qin

    2009-01-01

    The effects of solids retention time (SRT) and temperature on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation were investigated in a series of continuous-flow reactors at pH 10. The experimental results showed that the increase of either SRT or temperature benefited the hydrolysis of WAS and the production of SCFAs. The changes in SRT gave also impact on the percentage of acetic and propionic acids in the fermentative SCFAs, but little influence on that of the slightly long-chain SCFAs, such as n-butyric, iso-butyric, n-valeric and iso-valeric acids. Compared with the control (pH unadjusted) experiment, at SRT of 12d and temperature of 20 degrees C the concentration of SCFAs produced at pH 10 increased from 261.2 to 933.5mg COD/L, and the propionic acid percentage improved from 11.7 to 16.0%. It can be concluded from this investigation that the efficient continuous production of SCFAs at pH 10 is feasible.

  18. Agonist-induced production of 1,2-diacylglycerol and phosphatidic acid in intact resistance arteries. Evidence that accumulation of diacylglycerol is not a prerequisite for contraction.

    PubMed

    Ohanian, J; Ollerenshaw, J; Collins, P; Heagerty, A

    1990-05-25

    The production of total amounts of 1,2-diacylglycerol as well as those specifically derived from inositol lipid hydrolysis was studied in intact rat resistance arteries stimulated with either noradrenaline, vasopressin, or angiotensin II at 20 s when the onset of contraction would be nearing its maximum, and at 5 min during the sustained phase of contraction. Total amounts of 1,2-diacylglycerol were not altered by any agonist at 20 s, or at 5 min. However, arachidonate-containing species of 1,2-diacylglycerol were differentially influenced being increased at 5 min by noradrenaline, and decreased at 20 s and 5 min by vasopressin. Only angiotensin II produced substantial increases in this class of 1,2-diacylglycerol at both time points. In order to investigate the fate of this second messenger total and inositol lipid derived phosphatidic acids were then measured at both 20 s and 5 min. Noradrenaline induced a rise in both total and arachidonate-containing phosphatidic acid at both times as did vasopressin. Only small increases were induced by angiotensin II at 20 s. These data demonstrate that the accumulation of 1,2-diacylglycerol generated from inositol lipid breakdown is only observed with activation by angiotensin II. Other agonists produced phosphatidic acids with time and the rate of generation of these lipids is agonist-specific. Thus phosphatidic acid may play a more prominent role during the sustained phase of contraction than previously anticipated.

  19. Exogenous γ-aminobutyric acid treatment affects citrate and amino acid accumulation to improve fruit quality and storage performance of postharvest citrus fruit.

    PubMed

    Sheng, Ling; Shen, Dandan; Luo, Yi; Sun, Xiaohua; Wang, Jinqiu; Luo, Tao; Zeng, Yunliu; Xu, Juan; Deng, Xiuxin; Cheng, Yunjiang

    2017-02-01

    The loss of organic acids during postharvest storage is one of the major factors that reduces the fruit quality and economic value of citrus. Citrate is the most important organic acid in citrus fruits. Molecular evidence has proved that γ-aminobutyric acid (GABA) shunt plays a key role in citrate metabolism. Here, we investigated the effects of exogenous GABA treatment on citrate metabolism and storage quality of postharvest citrus fruit. The content of citrate was significantly increased, which was primarily attributed to the inhibition of the expression of glutamate decarboxylase (GAD). Amino acids, including glutamate, alanine, serine, aspartate and proline, were also increased. Moreover, GABA treatment decreased the fruit rot rate. The activities of antioxidant enzymes and the content of energy source ATP were affected by the treatment. Our results indicate that GABA treatment is a very effective approach for postharvest quality maintenance and improvement of storage performance in citrus production.

  20. Expression of the H+-ATPase AHA10 proton pump is associated with citric acid accumulation in lemon juice sac cells.

    PubMed

    Aprile, Alessio; Federici, Claire; Close, Timothy J; De Bellis, Luigi; Cattivelli, Luigi; Roose, Mikeal L

    2011-12-01

    The sour taste of lemons (Citrus limon (L.) Burm.) is determined by the amount of citric acid in vacuoles of juice sac cells. Faris is a "sweet" lemon variety since it accumulates low levels of citric acid. The University of California Riverside Citrus Variety Collection includes a Faris tree that produces sweet (Faris non-acid; FNA) and sour fruit (Faris acid; FA) on different branches; it is apparently a graft chimera with layer L1 derived from Millsweet limetta and layer L2 from a standard lemon. The transcription profiles of Faris sweet lemon were compared with Faris acid lemon and Frost Lisbon (L), which is a standard sour lemon genetically indistinguishable from Faris in prior work with SSR markers. Analysis of microarray data revealed that the transcriptomes of the two sour lemon genotypes were nearly identical. In contrast, the transcriptome of Faris sweet lemon was very different from those of both sour lemons. Among about 1,000 FNA-specific, presumably pH-related genes, the homolog of Arabidopsis H(+)-ATPase proton pump AHA10 was not expressed in FNA, but highly expressed in FA and L. Since Arabidopsis AHA10 is involved in biosynthesis and acidification of vacuoles, the lack of expression of the AHA10 citrus homolog represents a very conspicuous molecular feature of the FNA sweet phenotype. In addition, high expression of several 2-oxoglutarate degradation-related genes in FNA suggests activation of the GABA shunt and degradation of valine and tyrosine as components of the mechanism that reduces the level of citric acid in sweet lemon.

  1. Accumulation, selection and covariation of amino acids in sieve tube sap of tansy (Tanacetum vulgare) and castor bean (Ricinus communis): evidence for the function of a basic amino acid transporter and the absence of a γ-amino butyric acid transporter.

    PubMed

    Bauer, Susanne N; Nowak, Heike; Keller, Frank; Kallarackal, Jose; Hajirezaei, Mohamad-Reza; Komor, Ewald

    2014-09-01

    Sieve tube sap was obtained from Tanacetum by aphid stylectomy and from Ricinus after apical bud decapitation. The amino acids in sieve tube sap were analyzed and compared with those from leaves. Arginine and lysine accumulated in the sieve tube sap of Tanacetum more than 10-fold compared to the leaf extracts and they were, together with asparagine and serine, preferably selected into the sieve tube sap, whereas glycine, methionine/tryptophan and γ-amino butyric acid were partially or completely excluded. The two basic amino acids also showed a close covariation in sieve tube sap. The acidic amino acids also grouped together, but antagonistic to the other amino acids. The accumulation ratios between sieve tube sap and leaf extracts were smaller in Ricinus than in Tanacetum. Arginine, histidine, lysine and glutamine were enriched and preferentially loaded into the phloem, together with isoleucine and valine. In contrast, glycine and methionine/tryptophan were partially and γ-amino butyric acid almost completely excluded from sieve tube sap. The covariation analysis grouped arginine together with several neutral amino acids. The acidic amino acids were loaded under competition with neutral amino acids. It is concluded from comparison with the substrate specificities of already characterized plant amino acid transporters, that an AtCAT1-like transporter functions in phloem loading of basic amino acids, whereas a transporter like AtGAT1 is absent in phloem. Although Tanacetum and Ricinus have different minor vein architecture, their phloem loading specificities for amino acids are relatively similar.

  2. Crystal Structure of Okadaic Acid Binding Protein 2.1: A Sponge Protein Implicated in Cytotoxin Accumulation.

    PubMed

    Ehara, Haruhiko; Makino, Marie; Kodama, Koichiro; Konoki, Keiichi; Ito, Takuhiro; Sekine, Shun-ichi; Fukuzawa, Seketsu; Yokoyama, Shigeyuki; Tachibana, Kazuo

    2015-07-06

    Okadaic acid (OA) is a marine polyether cytotoxin that was first isolated from the marine sponge Halichondria okadai. OA is a potent inhibitor of protein serine/threonine phosphatases (PP) 1 and 2A, and the structural basis of phosphatase inhibition has been well investigated. However, the role and mechanism of OA retention in the marine sponge have remained elusive. We have solved the crystal structure of okadaic acid binding protein 2.1 (OABP2.1) isolated from H. okadai; it has strong affinity for OA and limited sequence homology to other proteins. The structure revealed that OABP2.1 consists of two α-helical domains, with the OA molecule deeply buried inside the protein. In addition, the global fold of OABP2.1 was unexpectedly similar to that of aequorin, a jellyfish photoprotein. The presence of structural homologues suggested that, by using similar protein scaffolds, marine invertebrates have developed diverse survival systems adapted to their living environments.

  3. Recombinant growth hormone enhances muscle myosin heavy-chain mRNA accumulation and amino acid accrual in humans.

    PubMed

    Fong, Y; Rosenbaum, M; Tracey, K J; Raman, G; Hesse, D G; Matthews, D E; Leibel, R L; Gertner, J M; Fischman, D A; Lowry, S F

    1989-05-01

    A potentially lethal complication of trauma, malignancy, and infection is a progressive erosion of muscle protein mass that is not readily reversed by nutritional support. Growth hormone is capable of improving total body nitrogen balance, but its role in myofibrillar protein synthesis in humans is unknown. The acute, in situ muscle protein response to an infusion of methionyl human growth hormone was investigated in the limbs of nutritionally depleted subjects during a period of intravenous refeeding. A 6-hr methionyl growth hormone infusion achieved steady-state serum levels comparable to normal physiologic peaks and was associated with a significant increase in limb amino acid uptake, without a change in body amino acid oxidation. Myosin heavy-chain mRNA levels, measured by quantitative dot blot hybridization, were also significantly elevated after growth hormone administration. The data indicate that methionyl growth hormone can induce intracellular amino acid accrual and increased levels of myofibrillar protein mRNA during hospitalized nutritional support and suggest growth hormone to be a potential therapy of lean body wasting.

  4. Cool-cultivated red leaf lettuce accumulates cyanidin-3-O-(6″-O-malonyl)-glucoside and caffeoylmalic acid.

    PubMed

    Becker, Christine; Klaering, Hans-Peter; Kroh, Lothar W; Krumbein, Angelika

    2014-03-01

    Cultivating lettuce in greenhouses at low temperatures improves its CO2-balance and may increase its content of flavonoid glycosides and phenolic acids. We cultivated 5weeks old red leaf lettuce seedlings at 20/15°C (day/night) or 12/7°C until plants reached comparable growth stages: small heads were harvested after 13 (warm) and 26 (cool)days, while mature heads were harvested after 26 (warm) or 52 (cool)days. Additionally, some plants were cultivated first cool then warm and vice versa (39days). Cool-cultivated small heads had higher concentrations of cyanidin-3-O-(6″-O-malonyl)-glucoside and caffeoylmalic acid than warm-cultivated ones but we detected no differences concerning quercetin and luteolin glycosides or di-O-caffeoyltartaric and 5-O-caffeoylquinic acid. Regarding mature heads, there were only differences concerning cyanidin-3-O-(6″-O-malonyl)-glucoside. We therefore suggest that only cyanidin-3-O-(6″-O-malonyl)-glucoside was truly responsive to temperatures alone. Previously reported contrasting effects may rather be due to comparison of different growth stages or interactive effects with radiation.

  5. Carbon monoxide fermentation to ethanol by Clostridium autoethanogenum in a bioreactor with no accumulation of acetic acid.

    PubMed

    Abubackar, Haris Nalakath; Veiga, María C; Kennes, Christian

    2015-06-01

    Fermentation of CO or syngas offers an attractive route to produce bioethanol. However, during the bioconversion, one of the challenges to overcome is to reduce the production of acetic acid in order to minimize recovery costs. Different experiments were done with Clostridium autoethanogenum. With the addition of 0.75 μM tungsten, ethanol production from carbon monoxide increased by about 128% compared to the control, without such addition, in batch mode. In bioreactors with continuous carbon monoxide supply, the maximum biomass concentration reached at pH 6.0 was 109% higher than the maximum achieved at pH 4.75 but, interestingly, at pH 4.75, no acetic acid was produced and the ethanol titer reached a maximum of 867 mg/L with minor amounts of 2,3-butanediol (46 mg/L). At the higher pH studied (pH 6.0) in the continuous gas-fed bioreactor, almost equal amounts of ethanol and acetic acid were formed, reaching 907.72 mg/L and 910.69 mg/L respectively.

  6. Light intensity and N/P nutrient affect the accumulation of lipid and unsaturated fatty acids by Chlorella sp.

    PubMed

    Guo, Xiaoyi; Su, Gaomin; Li, Zheng; Chang, Jingyu; Zeng, Xianhai; Sun, Yong; Lu, Yinghua; Lin, Lu

    2015-09-01

    In this study, different light intensities (80, 160, 240 and 320 μmol/m(2) s) and various mediums including control medium (CM), N/P rich medium (NPM), N rich medium (NM), and P rich medium (PM) were applied for cultivation of Chlorella sp. It was revealed that cultivation of Chlorella sp. in CM under the light intensity of 320 μmol/m(2) s led to a lipid content up to 30% enhancement, which was higher than the results of other cases. A rather high unsaturated fatty acid (UFA) content of 7.5% and unsaturated fatty acid/total fatty acid (UFA/TFA) ratio of 0.73 were obtained under 320 μmol/m(2) s in CM, indicating that the CM-320 system was applicable for the generation of UFA. Moreover, Chlorella sp. cultivated in PM under 320 μmol/m(2) s provided higher TFA content (7.3%), which was appropriate for biofuel production.

  7. Jasmonic acid-dependent and -independent signaling pathways control wound-induced gene activation in Arabidopsis thaliana.

    PubMed Central

    Titarenko, E; Rojo, E; León, J; Sánchez-Serrano, J J

    1997-01-01

    Plant response to mechanical injury includes gene activation both at the wound site and systemically in nondamaged tissues. The model developed for the wound-induced activation of the proteinase inhibitor II (Pin2) gene in potato (Solanum tuberosum) and tomato (Lycopersicon esculentum) establishes the involvement of the plant hormones abscisic acid and jasmonic acid (JA) as key components of the wound signal transduction pathway. To assess in Arabidopsis thaliana the role of these plant hormones in regulating wound-induced gene expression, we isolated wound- and JA-inducible genes by the differential mRNA display technique. Their patterns of expression upon mechanical wounding and hormonal treatments revealed differences in the spatial distribution of the transcripts and in the responsiveness of the analyzed genes to abscisic acid and JA. A correlation can be established between sensitivity to JA and the accumulation of the transcripts in systemic tissues upon wounding. A comparative study of the wound response in wild-type and JA-insensitive coi1 mutant plants indicated that in A. thaliana wound signals are transmitted via at least two different pathways. One of them does not involve JA as a mediator and is preferentially responsible for gene activation in the vicinity of the wound site, whereas the other requires JA perception and activates gene expression throughout the aerial part of the plant. PMID:9342878

  8. Is it a biological response or chemical process? Chemical and transcriptional regulation experiments probe the cause for the increased accumulation of chlorogenic acid (CGA) in carrot root slices exposed to UV-B light

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We recently demonstrated that wounded carrot roots subjected to a brief UV-B light treatment accumulate large quantities of chlorogenic acid (CGA) in the treated tissues. Chlorogenic acid is an intermediate in the phenylpropanoid pathway and a potent anti-oxidant. Chemical analysis and real-time P...

  9. Accumulation of acidic SK₃ dehydrins in phloem cells of cold- and drought-stressed plants of the Solanaceae.

    PubMed

    Szabala, Bartosz Mieczyslaw; Fudali, Sylwia; Rorat, Tadeusz

    2014-04-01

    The role of acidic SK(n) dehydrins in stress tolerance of important crop and model species of the Solanaceae remains unknown. We have previously shown that the acidic SK₃ dehydrin DHN24 from Solanum sogarandinum is constitutively expressed and its expression is associated with cold acclimation. Here we found that DHN24 is specifically localized to phloem cells of vegetative organs of non-acclimated plants. More precise localization of DHN24 revealed that it is primarily found in sieve elements (SEs) and companion cells (CCs) of roots and stems. In cold-acclimated plants, DHN24 is mainly present in all cell types of the phloem. Dhn24 transcripts are also predominantly localized to phloem cells of cold-acclimated stems. Immunoelectron microscopy localized DHN24 to the cytosol and close to organelle membranes of phloem cells, the lumen with phloem protein filaments, parietal cytoplasm of SEs and the nucleoplasm of some nuclei. Cell fractionation experiments revealed that DHN24 was detected in the cytosolic, nuclear and microsomal fractions. We also determined whether homologous members of the acidic subclass dehydrins from Capsicum annuum and Lycopersicon chilense share the characteristics of DHN24. We showed that they are also constitutively expressed, but their protein level is upregulated preferentially by drought stress. Immunofluorescent localization revealed that they are detected in SEs and CCs of unstressed plants and throughout the phloem in drought-stressed plants. These results suggest that one of the primary roles of DHN24 and its homologs may be the protection of the phloem region from adverse effects of abiotic stresses.

  10. Anaplerotic Accumulation of Tricarboxylic Acid Cycle Intermediates as Well as Changes in Other Key Metabolites During Heterotopic Ossification

    PubMed Central

    Davis, Eleanor L.; Salisbury, Elizabeth A.; Olmsted‐Davis, Elizabeth

    2015-01-01

    ABSTRACT Heterotopic ossification (HO) is the de novo formation of bone that occurs in soft tissue, through recruitment, expansion, and differentiation of multiple cells types including transient brown adipocytes, osteoblasts, chondrocytes, mast cells, and platelets to name a few. Much evidence is accumulating that suggests changes in metabolism may be required to accomplish this bone formation. Recent work using a mouse model of heterotopic bone formation reliant on delivery of adenovirus‐transduced cells expressing low levels of BMP2 showed the immediate expansion of a unique brown adipocyte‐like cell. These cells are undergoing robust uncoupled oxidative phosphorylation to a level such that oxygen in the microenvironment is dramatically lowered creating areas of hypoxia. It is unclear how these oxygen changes ultimately affect metabolism and bone formation. To identify the processes and changes occurring over the course of bone formation, HO was established in the mice, and tissues isolated at early and late times were subjected to a global metabolomic screen. Results show that there are significant changes in both glucose levels, as well as TCA cycle intermediates. Additionally, metabolites necessary for oxidation of stored lipids were also found to be significantly elevated. The complete results of this screen are presented here, and provide a unique picture of the metabolic changes occurring during heterotopic bone formation. J. Cell. Biochem. 117: 1044–1053, 2016. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc. PMID:26627193

  11. Hatching, growth, ion accumulation, and skeletal ossification of brook trout (Salvelinus fontinalis) alevins in acidic soft waters

    USGS Publications Warehouse

    Steingraeber, M.T.; Gingerich, W.H.

    1991-01-01

    Brook trout eyed eggs and subsequent alevins were exposed to pH 5.0, 6.5, and 7.0 in soft reconstituted water and to pH 8.2 in hard well water for up to 72 d. Hatching was delayed and hatching success reduced (p K+ > Cl- during yolk absorption and early exogenous feeding. Whole-body monovalent ion concentrations were reduced for short periods during yolk absorption in alevins exposed to pH 6.5 and throughout most of the experiment for those exposed to pH 5.0. Whole-body Mg2+ concentrations were not affected by treatment pH and remained near their median hatch level throughout the exposure. The whole-body concentration of Ca2+ was reduced in fish exposed to pH 5.0, particularly near the end of the experiment. Calcium accumulation in fish was influenced by the interaction of pH and time at pH 5.0 but not at the other pH levels. Alevins exposed to pH 5.0 experienced delayed ossification of skeletal structures associated with feeding, respiration, and locomotion that usually persisted for up to 10 d. The detection of skeletal abnormalities early in life might aid in identifying fish populations at risk in acidified waters.

  12. Influence of Light and Temperature on Gene Expression Leading to Accumulation of Specific Flavonol Glycosides and Hydroxycinnamic Acid Derivatives in Kale (Brassica oleracea var. sabellica).

    PubMed

    Neugart, Susanne; Krumbein, Angelika; Zrenner, Rita

    2016-01-01

    Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plants were grown either at 400 μmol m(-2) s(-1) or 100 μmol m(-2) s(-1) at 10°C, or at 400 μmol m(-2) s(-1) with 5 or 15°C. The higher light intensity overall increased flavonol content of leaves, favoring the main quercetin glycosides, a caffeic acid monoacylated kaempferol triglycoside, and disinapoyl-gentiobiose. The higher temperature mainly increased the hydroxycinnamic acid derivative disinapoyl-gentiobiose, while at lower temperature synthesis is in favor of very complex sinapic acid acylated flavonol tetraglycosides such as kaempferol-3-O-sinapoyl-sophoroside-7-O-diglucoside. A global analysis of light and temperature dependent alterations of gene expression in B. oleracea var. sabellica leaves was performed with the most comprehensive Brassica microarray. When compared to the light experiment much less genes were differentially expressed in kale leaves grown at 5 or 15°C. A structured evaluation of differentially expressed genes revealed the expected enrichment in the functional categories of e.g. protein degradation at different light intensities or phytohormone metabolism at different temperature. Genes of the secondary metabolism namely phenylpropanoids are significantly enriched with both treatments. Thus, the genome of B. oleracea was screened for predicted genes putatively involved in the biosynthesis of flavonoids and hydroxycinnamic acid derivatives. All identified B. oleracea genes were analyzed for their most specific 60-mer oligonucleotides present on the

  13. Influence of Light and Temperature on Gene Expression Leading to Accumulation of Specific Flavonol Glycosides and Hydroxycinnamic Acid Derivatives in Kale (Brassica oleracea var. sabellica)

    PubMed Central

    Neugart, Susanne; Krumbein, Angelika; Zrenner, Rita

    2016-01-01

    Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plants were grown either at 400 μmol m−2 s−1 or 100 μmol m−2 s−1 at 10°C, or at 400 μmol m−2 s−1 with 5 or 15°C. The higher light intensity overall increased flavonol content of leaves, favoring the main quercetin glycosides, a caffeic acid monoacylated kaempferol triglycoside, and disinapoyl-gentiobiose. The higher temperature mainly increased the hydroxycinnamic acid derivative disinapoyl-gentiobiose, while at lower temperature synthesis is in favor of very complex sinapic acid acylated flavonol tetraglycosides such as kaempferol-3-O-sinapoyl-sophoroside-7-O-diglucoside. A global analysis of light and temperature dependent alterations of gene expression in B. oleracea var. sabellica leaves was performed with the most comprehensive Brassica microarray. When compared to the light experiment much less genes were differentially expressed in kale leaves grown at 5 or 15°C. A structured evaluation of differentially expressed genes revealed the expected enrichment in the functional categories of e.g. protein degradation at different light intensities or phytohormone metabolism at different temperature. Genes of the secondary metabolism namely phenylpropanoids are significantly enriched with both treatments. Thus, the genome of B. oleracea was screened for predicted genes putatively involved in the biosynthesis of flavonoids and hydroxycinnamic acid derivatives. All identified B. oleracea genes were analyzed for their most specific 60-mer oligonucleotides present on the

  14. Fat accumulation, fatty acids and melting point changes in broiler chick abdominal fat as affected by time of dietary fat feeding and slaughter age.

    PubMed

    Carmona, J M; Lopez-Bote, C J; Daza, A; Rey, A I

    2017-03-23

    1. This work aims to quantify changes in fatty acid profile, melting point, abdominal fat accumulation and 2-thiobarbituric acid-reactive substances production depending on dietary fat source and age at slaughter, and to estimate the optimal date for the change from an unsaturated fat to a saturated fat diet or vice versa. 2. Treatments established were (1) birds fed 8% tallow from 21 to 49 d (TTT); (2) birds fed 8% tallow from 21 to 37 d and 8% sunflower oil from d 38 to 49 (TSS); (3) birds fed 8% sunflower oil from 21 to 37 d and 8% tallow from d 38 to 49 (STT); (4) birds fed 8% sunflower oil from 21 to 41 d and 8% tallow from d 42 to 49 (SST); (5) birds fed 8% sunflower oil from 21 to 49 d (SSS). Birds from each group were slaughtered on d 21, 29, 38, 40, 42, 44, 46 and 49. 3. The polyunsaturated fatty acids (PUFAs) proportion in the SSS group reached maximum values at d 40 and fitted a quadratic response. This group also showed a decrease in saturated fatty acids (SATs) and monounsaturated fatty acids (MUFAs) of lower intensity than the PUFA increase. The highest synthesis of SAT + MUFA was found in the SSS and TSS groups, whereas these had the lowest body-to-dietary PUFA ratio. 4. A high and quadratic increase in the MUFA proportion was observed during the first 10 d of feeding with the tallow-enriched diet at the expenses of the proportion of PUFA that quadratically decreased (minimum values at d 38). 5. Lipogenic and desaturation capacity decreased with age. 6. The TSS group increased tissue PUFA content faster that the SST group decreased PUFA content after the change in diet which indicates that the earlier feeding has to be taken into consideration for obtaining higher or lower changes in quality parameters. 7. The melting point of the SSS group showed a lower response to the dietary treatment in the initial period when compared to the TTT treatment. 8. The TTT, STT, SST and TSS groups showed similar fat accumulation, and changes in lipid

  15. Tamoxifen-induced anorexia is associated with fatty acid synthase inhibition in the ventromedial nucleus of the hypothalamus and accumulation of malonyl-CoA.

    PubMed

    López, Miguel; Lelliott, Christopher J; Tovar, Sulay; Kimber, Wendy; Gallego, Rosalía; Virtue, Sam; Blount, Margaret; Vázquez, Maria J; Finer, Nick; Powles, Trevor J; O'Rahilly, Stephen; Saha, Asish K; Diéguez, Carlos; Vidal-Puig, Antonio J

    2006-05-01

    Fatty acid metabolism in the hypothalamus has recently been shown to regulate feeding. The selective estrogen receptor modulator tamoxifen (TMX) exerts a potent anorectic effect. Here, we show that the anorectic effect of TMX is associated with the accumulation of malonyl-CoA in the hypothalamus and inhibition of fatty acid synthase (FAS) expression specifically in the ventromedial nucleus of the hypothalamus (VMN). Furthermore, we demonstrate that FAS mRNA expression is physiologically regulated by fasting and refeeding in the VMN but not in other hypothalamic nuclei. Thus, the VMN appears to be the hypothalamic site where regulation of FAS and feeding converge. Supporting the potential clinical relevance of these observations, reanalysis of a primary breast cancer prevention study showed that obese women treated with TMX gained significantly less body weight over a 6-year period than obese women given placebo. The finding that TMX can modulate appetite through alterations in FAS expression and malonyl-CoA levels suggests a link between hypothalamic sex steroid receptors, fatty acid metabolism, and feeding behavior.

  16. The Combined Effects of Ethylene and MeJA on Metabolic Profiling of Phenolic Compounds in Catharanthus roseus Revealed by Metabolomics Analysis.

    PubMed

    Liu, Jia; Liu, Yang; Wang, Yu; Zhang, Zhong-Hua; Zu, Yuan-Gang; Efferth, Thomas; Tang, Zhong-Hua

    2016-01-01

    Phenolic compounds belong to a class of secondary metabolites and are implicated in a wide range of responsive mechanisms in plants triggered by both biotic and abiotic elicitors. In this study, we approached the combinational effects of ethylene and MeJA (methyl jasmonate) on phenolic compounds profiles and gene expressions in the medicinal plant Catharanthus roseus. In virtue of a widely non-targeted metabolomics method, we identified a total of 34 kinds of phenolic compounds in the leaves, composed by 7 C6C1-, 11 C6C3-, and 16 C6C3C6 compounds. In addition, 7 kinds of intermediates critical for the biosynthesis of phenolic compounds and alkaloids were identified and discussed with phenolic metabolism. The combinational actions of ethylene and MeJA effectively promoted the total phenolic compounds, especially the C6C1 compounds (such as salicylic acid, benzoic acid) and C6C3 ones (such as cinnamic acid, sinapic acid). In contrast, the C6C3C6 compounds displayed a notably inhibitory trend in this case. Subsequently, the gene-to-metabolite networks were drawn up by searching for correlations between the expression profiles of 5 gene tags and the accumulation profiles of 41 metabolite peaks. Generally, we provide an insight into the controlling mode of ethylene-MeJA combination on phenolic metabolism in C. roseus leaves.

  17. The Combined Effects of Ethylene and MeJA on Metabolic Profiling of Phenolic Compounds in Catharanthus roseus Revealed by Metabolomics Analysis

    PubMed Central

    Liu, Jia; Liu, Yang; Wang, Yu; Zhang, Zhong-Hua; Zu, Yuan-Gang; Efferth, Thomas; Tang, Zhong-Hua

    2016-01-01

    Phenolic compounds belong to a class of secondary metabolites and are implicated in a wide range of responsive mechanisms in plants triggered by both biotic and abiotic elicitors. In this study, we approached the combinational effects of ethylene and MeJA (methyl jasmonate) on phenolic compounds profiles and gene expressions in the medicinal plant Catharanthus roseus. In virtue of a widely non-targeted metabolomics method, we identified a total of 34 kinds of phenolic compounds in the leaves, composed by 7 C6C1-, 11 C6C3-, and 16 C6C3C6 compounds. In addition, 7 kinds of intermediates critical for the biosynthesis of phenolic compounds and alkaloids were identified and discussed with phenolic metabolism. The combinational actions of ethylene and MeJA effectively promoted the total phenolic compounds, especially the C6C1 compounds (such as salicylic acid, benzoic acid) and C6C3 ones (such as cinnamic acid, sinapic acid). In contrast, the C6C3C6 compounds displayed a notably inhibitory trend in this case. Subsequently, the gene-to-metabolite networks were drawn up by searching for correlations between the expression profiles of 5 gene tags and the accumulation profiles of 41 metabolite peaks. Generally, we provide an insight into the controlling mode of ethylene-MeJA combination on phenolic metabolism in C. roseus leaves. PMID:27375495

  18. β-Aminobutyric acid increases abscisic acid accumulation and desiccation tolerance and decreases water use but fails to improve grain yield in two spring wheat cultivars under soil drying

    PubMed Central

    Li, Feng-Min

    2012-01-01

    A pot experiment was conducted to investigate the effect of the non-protein amino acid, β-aminobutyric acid (BABA), on the homeostasis between reactive oxygen species (ROS) and antioxidant defence during progressive soil drying, and its relationship with the accumulation of abscisic acid (ABA), water use, grain yield, and desiccation tolerance in two spring wheat (Triticum aestivum L.) cultivars released in different decades and with different yields under drought. Drenching the soil with 100 µM BABA increased drought-induced ABA production, leading to a decrease in the lethal leaf water potential (Ψ) used to measure desiccation tolerance, decreased water use, and increased water use efficiency for grain (WUEG) under moderate water stress. In addition, at severe water stress levels, drenching the soil with BABA reduced ROS production, increased antioxidant enzyme activity, and reduced the oxidative damage to lipid membranes. The data suggest that the addition of BABA triggers ABA accumulation that acts as a non-hydraulic root signal, thereby closing stomata, and reducing water use at moderate stress levels, and also reduces the production of ROS and increases the antioxidant defence enzymes at severe stress levels, thus increasing the desiccation tolerance. However, BABA treatment had no effect on grain yield of wheat when water availability was limited. The results suggest that there are ways of effectively priming the pre-existing defence pathways, in addition to genetic means, to improve the desiccation tolerance and WUEG of wheat. PMID:22859677

  19. Silverleaf Whitefly Induces Salicylic Acid Defenses and Suppresses Effectual Jasmonic Acid Defenses1[W][OA

    PubMed Central

    Zarate, Sonia I.; Kempema, Louisa A.; Walling, Linda L.

    2007-01-01

    The basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (Bemisia tabaci type B; SLWF) on Arabidopsis (Arabidopsis thaliana) were investigated. Sentinel defense gene RNAs were monitored in SLWF-infested and control plants. Salicylic acid (SA)-responsive gene transcripts accumulated locally (PR1, BGL2, PR5, SID2, EDS5, PAD4) and systemically (PR1, BGL2, PR5) during SLWF nymph feeding. In contrast, jasmonic acid (JA)- and ethylene-dependent RNAs (PDF1.2, VSP1, HEL, THI2.1, FAD3, ERS1, ERF1) were repressed or not modulated in SLWF-infested leaves. To test for a role of SA and JA pathways in basal defense, SLWF development on mutant and transgenic lines that constitutively activate or impair defense pathways was determined. By monitoring the percentage of SLWF nymphs in each instar, we show that mutants that activate SA defenses (cim10) or impair JA defenses (coi1) accelerated SLWF nymphal development. Reciprocally, mutants that activate JA defenses (cev1) or impair SA defenses (npr1, NahG) slowed SLWF nymphal development. Furthermore, when npr1 plants, which do not activate downstream SA defenses, were treated with methyl jasmonate, a dramatic delay in nymph development was observed. Collectively, these results showed that SLWF-repressed, JA-regulated defenses were associated with basal defense to the SLWF. PMID:17189328

  20. Silverleaf whitefly induces salicylic acid defenses and suppresses effectual jasmonic acid defenses.

    PubMed

    Zarate, Sonia I; Kempema, Louisa A; Walling, Linda L

    2007-02-01

    The basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (Bemisia tabaci type B; SLWF) on Arabidopsis (Arabidopsis thaliana) were investigated. Sentinel defense gene RNAs were monitored in SLWF-infested and control plants. Salicylic acid (SA)-responsive gene transcripts accumulated locally (PR1, BGL2, PR5, SID2, EDS5, PAD4) and systemically (PR1, BGL2, PR5) during SLWF nymph feeding. In contrast, jasmonic acid (JA)- and ethylene-dependent RNAs (PDF1.2, VSP1, HEL, THI2.1, FAD3, ERS1, ERF1) were repressed or not modulated in SLWF-infested leaves. To test for a role of SA and JA pathways in basal defense, SLWF development on mutant and transgenic lines that constitutively activate or impair defense pathways was determined. By monitoring the percentage of SLWF nymphs in each instar, we show that mutants that activate SA defenses (cim10) or impair JA defenses (coi1) accelerated SLWF nymphal development. Reciprocally, mutants that activate JA defenses (cev1) or impair SA defenses (npr1, NahG) slowed SLWF nymphal development. Furthermore, when npr1 plants, which do not activate downstream SA defenses, were treated with methyl jasmonate, a dramatic delay in nymph development was observed. Collectively, these results showed that SLWF-repressed, JA-regulated defenses were associated with basal defense to the SLWF.

  1. Organic acids, amino acids compositions in the root exudates and Cu-accumulation in castor (Ricinus communis L.) Under Cu stress.

    PubMed

    Huang, Guoyong; Guo, Guangguang; Yao, Shiyuan; Zhang, Na; Hu, Hongqing

    2016-01-01

    Ricinus communis L. is a hyperaccumulation plant newly discovered in an abandoned land of Cu mine in China. A hydroponic experiment was then carried out to determine the root exudates in the Cu-tolerant castor (Ricinus communis L.). Plants were grown in nutrient solution with increasing level of Cu doses (0, 100, 250, 500, and 750 μmol/L Cu) in the form of CuSO4. Cu accumulation in the roots and shoots of castor, and root exudates collected from the castor were measured. The results indicated that the castor had a high Cu accumulation capacity and the Cu concentrations in the shoots and roots of the castor treated with 750 μmol/L Cu were 177.1, 14586.7 mg/kg, respectively. Tartaric was the largest in the root exudates in terms of concentrations, which reached up to 329.13 μmol/g (dry plant) in the level of 750 μmol/L Cu. There was a significantly positive linear relationship between the Cu concentration in root and the concentration of succinic (R = 0.92, P < 0.05), tartaric (R = 0.96, P < 0.01), and citric (R = 0.89, P < 0.05). These results indicated that the difference in root exudation from castor could affect their Cu tolerance. What is more, significant is that the high tartaric and citric, the low oxalic and cysteine in the root exudation of castor contributed to toleration of high Cu concentrations.

  2. The biocide tributyltin reduces the accumulation of testosterone as fatty acid esters in the mud snail (Ilyanassa obsoleta).

    PubMed Central

    Gooding, Meredith P; Wilson, Vickie S; Folmar, Leroy C; Marcovich, Dragoslav T; LeBlanc, Gerald A

    2003-01-01

    Imposex, the development of male sex characteristics by female gonochoristic snails, has been documented globally and is causally associated with exposure to the ubiquitous environmental contaminant tributyltin (TBT). Elevated testosterone levels in snails also are associated with TBT, and direct exposure to testosterone has been shown to cause imposex. We discovered previously that the mud snail (Ilyanassa obsoleta)biotransforms and retains excess testosterone primarily as fatty acid esters. The purpose of this study was to determine whether TBT interferes with the esterification of testosterone, resulting in the elevated free (unesterified) testosterone levels associated with imposex. Exposure of snails to environmentally relevant concentrations of TBT (> or = 1.0 ng/L as tin) significantly increased the incidence of imposex. Total (free + esterified) testosterone levels in snails were not altered by TBT; however, free testosterone levels increased with increasing exposure concentration of TBT. TBT-exposed snails were given [14C

  3. Silencing of ABCC13 transporter in wheat reveals its involvement in grain development, phytic acid accumulation and lateral root formation

    PubMed Central

    Bhati, Kaushal Kumar; Alok, Anshu; Kumar, Anil; Kaur, Jagdeep; Tiwari, Siddharth; Pandey, Ajay Kumar

    2016-01-01

    Low phytic acid is a trait desired in cereal crops and can be achieved by manipulating the genes involved either in its biosynthesis or its transport in the vacuoles. Previously, we have demonstrated that the wheat TaABCC13 protein is a functional transporter, primarily involved in heavy metal tolerance, and a probable candidate gene to achieve low phytate wheat. In the current study, RNA silencing was used to knockdown the expression of TaABCC13 in order to evaluate its functional importance in wheat. Transgenic plants with significantly reduced TaABCC13 transcripts in either seeds or roots were selected for further studies. Homozygous RNAi lines K1B4 and K4G7 exhibited 34–22% reduction of the phytic acid content in the mature grains (T4 seeds). These transgenic lines were defective for spike development, as characterized by reduced grain filling and numbers of spikelets. The seeds of transgenic wheat had delayed germination, but the viability of the seedlings was unaffected. Interestingly, early emergence of lateral roots was observed in TaABCC13-silenced lines as compared to non-transgenic lines. In addition, these lines also had defects in metal uptake and development of lateral roots in the presence of cadmium stress. Our results suggest roles of TaABCC13 in lateral root initiation and enhanced sensitivity towards heavy metals. Taken together, these data demonstrate that wheat ABCC13 is functionally important for grain development and plays an important role during detoxification of heavy metals. PMID:27342224

  4. Silencing of ABCC13 transporter in wheat reveals its involvement in grain development, phytic acid accumulation and lateral root formation.

    PubMed

    Bhati, Kaushal Kumar; Alok, Anshu; Kumar, Anil; Kaur, Jagdeep; Tiwari, Siddharth; Pandey, Ajay Kumar

    2016-07-01

    Low phytic acid is a trait desired in cereal crops and can be achieved by manipulating the genes involved either in its biosynthesis or its transport in the vacuoles. Previously, we have demonstrated that the wheat TaABCC13 protein is a functional transporter, primarily involved in heavy metal tolerance, and a probable candidate gene to achieve low phytate wheat. In the current study, RNA silencing was used to knockdown the expression of TaABCC13 in order to evaluate its functional importance in wheat. Transgenic plants with significantly reduced TaABCC13 transcripts in either seeds or roots were selected for further studies. Homozygous RNAi lines K1B4 and K4G7 exhibited 34-22% reduction of the phytic acid content in the mature grains (T4 seeds). These transgenic lines were defective for spike development, as characterized by reduced grain filling and numbers of spikelets. The seeds of transgenic wheat had delayed germination, but the viability of the seedlings was unaffected. Interestingly, early emergence of lateral roots was observed in TaABCC13-silenced lines as compared to non-transgenic lines. In addition, these lines also had defects in metal uptake and development of lateral roots in the presence of cadmium stress. Our results suggest roles of TaABCC13 in lateral root initiation and enhanced sensitivity towards heavy metals. Taken together, these data demonstrate that wheat ABCC13 is functionally important for grain development and plays an important role during detoxification of heavy metals.

  5. Betaine alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet.

    PubMed

    Xu, Li; Huang, Danping; Hu, Qiaolin; Wu, Jing; Wang, Yizhen; Feng, Jie

    2015-06-28

    To assess the effects of betaine on hepatic lipid accumulation and investigate the underlying mechanism, thirty-two male Sprague-Dawley rats weighing 100 (sd 2·50) g were divided into four groups, and started on one of four treatments: basal diet, basal diet with betaine administration, high-fat diet and high-fat diet with betaine administration. The results showed that no significant difference of body weight was found among experimental groups. Compared with high-fat diet-fed rats, a betaine supplementation decreased (P< 0·05) hepatic TAG accumulation induced by high-fat diet, which was also supported by hepatic histology results. Additionally, hepatic betaine-homocysteine methyltransferase concentration [corrected] as well as its mRNA abundance and lecithin level were found increased (P< 0·05) by betaine supplementation in both basal diet-fed rats and high-fat diet-fed rats. Betaine administration in high-fat diet-fed rats exhibited a higher (P< 0·05) concentration [corrected] of hepatic carnitine palmitoyltransferase 1 (CPT1) compared with high-fat diet-fed rats. High-fat diet inhibited (P< 0·05) the gene expression of hepatic PPARα and CPT1. However, betaine administration in high-fat diet-fed rats elevated (P< 0·05) the gene expression of PPARα and CPT1. Moreover, concentration, gene and protein expressions of hepatic fibroblast growth factor 21 (FGF21) were increased (P< 0·05) in response to betaine administration in high-fat diet group; meanwhile the gene expression of hepatic AMP-activated protein kinase was increased (P< 0·05) as well. The results suggest that betaine administration enhanced hepatic lipid export and fatty acid oxidation in high-fat diet-fed rats, thus effectively alleviating fat accumulation in the liver.

  6. Effects of dietary palmitoleic acid on plasma lipoprotein profile and aortic cholesterol accumulation are similar to those of other unsaturated fatty acids in the F1B golden Syrian hamster.

    PubMed

    Matthan, Nirupa R; Dillard, Alice; Lecker, Jaime L; Ip, Blanche; Lichtenstein, Alice H

    2009-02-01

    The lower susceptibility of palmitoleic acid (16:1) to oxidation compared to PUFA may confer functional advantages with respect to finding acceptable alternatives to partially hydrogenated fats, but limited data are available on its effect on cardiovascular risk factors. This study investigated the effect of diets (10% fat, 0.1% cholesterol, wt:wt) enriched with macadamia [monounsaturated fatty acid (MUFA)16:1], palm (SFA,16:0), canola (MUFA,18:1), or safflower (PUFA,18:2) oils on lipoprotein profiles and aortic cholesterol accumulation in F1B Golden Syrian hamsters (n = 16/group). After 12 wk, 8 hamsters in each group were killed (phase 1). The remaining hamsters fed palm oil were changed to a diet containing coconut oil, while hamsters in the other diet groups continued on their original diets for an additional 6 wk (phase 2). With minor exceptions, the time course and dietary SFA source did not alter the study outcomes. Macadamia oil-fed hamsters had lower non-HDL cholesterol and triglyceride concentrations compared with the palm and coconut oil-fed hamsters and higher HDL-cholesterol compared with the coconut, canola, and safflower oil-fed hamsters. The aortic cholesterol concentration was not affected by dietary fat type. The hepatic cholesterol concentration was higher in the unsaturated compared with the saturated oil-fed hamsters. RBC membrane and aortic cholesteryl ester, triglyceride, and phospholipid fatty acid profiles reflected that of the dietary oil. These data suggest that an oil relatively high in palmitoleic acid does not adversely affect plasma lipoprotein profiles or aortic cholesterol accumulation and was similar to other unsaturated fatty acid-rich oils.

  7. GABA shunt and polyamine degradation pathway on γ-aminobutyric acid accumulation in germinating fava bean (Vicia faba L.) under hypoxia.

    PubMed

    Yang, Runqiang; Guo, Qianghui; Gu, Zhenxin

    2013-01-01

    GABA shunt and polyamine degradation pathway on γ-aminobutyric acid (GABA) accumulation in germinating fava bean under hypoxia was investigated. GABA content, GAD and DAO activity were significantly increased under hypoxia treatment. Glu and polyamine contents enhanced largely and thus supplied as sufficient substrates for GABA formation. In contrast, GABA content decreased, mainly in the embryo, after removing the hypoxia stress. DAO activity, Glu and polyamines contents decreased, while an increment of GAD activity was observed. This indicated that GAD activity can be not only regulated by hypoxia, but by the rapid growth of embryo after the recovery from hypoxia stress. When treated with AG, DAO activity was almost inhibited completely, and the GABA content decreased by 32.96% and 32.07% after treated for 3 and 5 days, respectively. Hence, it can be inferred that about 30% of GABA formed in germinating fava bean under hypoxia was supplied by polyamine degradation pathway.

  8. Accumulation of γ‐aminobutyric acid by E nterococcus avium 9184 in scallop solution in a two‐stage fermentation strategy

    PubMed Central

    Yang, Haoyue; Hu, Linfeng; Liu, Song

    2015-01-01

    Summary In this study, a new bacterial strain having a high ability to produce γ‐aminobutyric acid (GABA) was isolated from naturally fermented scallop solution and was identified as E nterococcus avium. To the best of our knowledge, this is the first study to prove that E . avium possesses glutamate decarboxylase activity. The strain was then mutagenized with UV radiation and was designated as E . avium 9184. Scallop solution was used as the culture medium to produce GABA. A two‐stage fermentation strategy was applied to accumulate GABA. In the first stage, cell growth was regulated. Optimum conditions for cell growth were pH, 6.5; temperature, 37°C; and glucose concentration, 10 g·L−1. This produced a maximum dry cell mass of 2.10 g·L−1. In the second stage, GABA formation was regulated. GABA concentration reached 3.71 g·L−1 at 96 h pH 6.0, 37°C and initial l‐monosodium glutamate concentration of 10 g·L−1. Thus, compared with traditional one‐stage fermentation, the two‐stage fermentation significantly increased GABA accumulation. These results provide preliminary data to produce GABA using E . avium and also provide a new approach to process and utilize shellfish. PMID:26200650

  9. Salicylic acid treatment reduces the rot of postharvest citrus fruit by inducing the accumulation of H2O2, primary metabolites and lipophilic polymethoxylated flavones.

    PubMed

    Zhu, Feng; Chen, Jiajing; Xiao, Xue; Zhang, Mingfei; Yun, Ze; Zeng, Yunliu; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2016-09-15

    To comprehensively analyze the effects of salicylic acid (SA) on the storability of Satsuma mandarin (Citrus unshiu), fruits were treated with 2mM SA. The disease incidence of control/SA-treated fruit at 50d and 120d after treatment was 23.3%/10% and 67.3%/23.3%, respectively, suggesting that SA treatment can significantly reduce the rot rate of postharvest citrus fruit. Fruit quality assays revealed that the treatment can maintain fruit firmness without affecting the inner quality. Furthermore, the contents of H2O2 and some defense-related metabolites, such as ornithine and threonine, in citrus pericarp, were significantly increased by SA treatment. Moreover, it was lipophilic polymethoxylated flavones, rather than flavanone glycosides, that accumulated in SA-treated fruits and these can directly inhibit pathogen development. These results suggest that the effects of SA on postharvest citrus fruit may be attributed to the accumulation of H2O2 and defense-related metabolites.

  10. Impact of Precooling and Controlled-Atmosphere Storage on γ-Aminobutyric Acid (GABA) Accumulation in Longan (Dimocarpus longan Lour.) Fruit.

    PubMed

    Zhou, Molin; Ndeurumio, Kessy H; Zhao, Lei; Hu, Zhuoyan

    2016-08-24

    Longan (Dimocarpus longan Lour.) fruit cultivars 'Chuliang' and 'Shixia' were analyzed for γ-aminobutyric acid (GABA) accumulation after precooling and in controlled-atmosphere storage. Fruit were exposed to 5% O2 plus 3%, 5%, or 10% CO2 at 4 °C, and GABA and associated enzymes, aril firmness, and pericarp color were measured. Aril softening and pericarp browning were delayed by 5% CO2 + 5% O2. GABA concentrations and glutamate decarboxylase (GAD; EC 4.1.1.15) activities declined during storage at the higher-CO2 treatments. However, GABA aminotransferase (GABA-T; EC 2.6.1.19) activities in elevated CO2-treated fruit fluctuated during storage. GABA concentrations increased after precooling treatments. GAD activity and GABA-T activity were different between cultivars after precooling. GABA concentrations in fruit increased after 3 days of 10% CO2 + 5% O2 treatment and then declined as storage time increased. GABA accumulation was associated with stimulation of GAD activity rather than inhibition of GABA-T activity.

  11. Hydrolysis and volatile fatty acids accumulation of waste activated sludge enhanced by the combined use of nitrite and alkaline pH.

    PubMed

    Huang, Cheng; Liu, Congcong; Sun, Xiuyun; Sun, Yinglu; Li, Rui; Li, Jiansheng; Shen, Jinyou; Han, Weiqing; Liu, Xiaodong; Wang, Lianjun

    2015-12-01

    Volatile fatty acids (VFAs) production from anaerobic digestion of waste activated sludge (WAS) is often limited by the slow hydrolysis and/or poor substrate availability. Increased attention has been given to enhance the hydrolysis and acidification of WAS recently. This study presented an efficient and green strategy based on the combined use of nitrite pretreatment and alkaline pH to stimulate hydrolysis and VFA accumulation from WAS. Results showed that both proteins and polysaccharides increased in the presence of nitrite, indicating the enhancement of sludge solubilization and hydrolysis processes. Mechanism investigations showed that nitrite pretreatment could disintegrate the sludge particle and disperse extracellular polymeric substances (EPS). Then, anaerobic digestion tests demonstrated VFA production increased with nitrite treatment. The maximal VFA accumulation was achieved with 0.1 g N/L nitrite dosage and pH 10.0 at a sludge retention time (SRT) of 7 days, which was much higher VFA production in comparison with the blank, sole nitrite pretreatment, or sole pH 10. The potential analysis suggested that the combined nitrite pretreatment and alkaline pH is capable of enhancing WAS digestion with a great benefit for biological nutrient removal (BNR).

  12. Topical glycerol monooleate/propylene glycol formulations enhance 5-aminolevulinic acid in vitro skin delivery and in vivo protophorphyrin IX accumulation in hairless mouse skin.

    PubMed

    Steluti, Regilene; De Rosa, Fernanda Scarmato; Collett, John; Tedesco, Antônio Cláudio; Bentley, Maria Vitória Lopes Badra

    2005-08-01

    Photodynamic therapy (PDT), a potential therapy for cancer treatment, utilizes exogenously applied or endogenously formed photosensitizers, further activated by light in an appropriate wavelength and dose to induce cell death through free radical formation. 5-Aminolevulinic acid (5-ALA) is a pro-drug which can be converted to the effective photosensitizer, protoporphyrin IX (PpIX). However, the use of 5-ALA in PDT is limited by the low penetration capacity of this highly hydrophilic molecule into appropriate skin layers. In the present study, we propose to increase 5-ALA penetration by using formulations containing glycerol monooleate (GMO), an interesting and useful component of pharmaceutical formulations. Propylene glycol solutions containing different concentrations of GMO significantly increased the in vitro skin permeation/retention of 5-ALA in comparison to control solutions. In vivo studies also showed increased PpIX accumulation in mouse hairless skin, after the use of topical 5-ALA formulations containing GMO in a concentration-dependent manner. The results show that skin 5-ALA penetration and PpIX accumulation, important factors for the success of topical 5-ALA-PDT in skin cancer, are optimized by GMO/propylene glycol formulations.

  13. Sediment accumulation, stratigraphic order, and the extent of time-averaging in lagoonal sediments: a comparison of 210Pb and 14C/amino acid racemization chronologies

    NASA Astrophysics Data System (ADS)

    Kosnik, Matthew A.; Hua, Quan; Kaufman, Darrell S.; Zawadzki, Atun

    2015-03-01

    Carbon-14 calibrated amino acid racemization (14C/AAR) data and lead-210 (210Pb) data are used to examine sediment accumulation rates, stratigraphic order, and the extent of time-averaging in sediments collected from the One Tree Reef lagoon (southern Great Barrier Reef, Australia). The top meter of lagoonal sediment preserves a stratigraphically ordered deposit spanning the last 600 yrs. Despite different assumptions, the 210Pb and 14C/AAR chronologies are remarkably similar indicating consistency in sedimentary processes across sediment grain sizes spanning more than three orders of magnitude (0.1-10 mm). Estimates of long-term sediment accumulation rates range from 2.2 to 1.2 mm yr-1. Molluscan time-averaging in the taphonomically active zone is 19 yrs, whereas below the depth of final burial (~15 cm), it is ~110 yrs/5 cm layer. While not a high-resolution paleontological record, this reef lagoon sediment is suitable for paleoecological studies spanning the period of Western colonization and development. This sedimentary deposit, and others like it, should be useful, albeit not ideal, for quantifying anthropogenic impacts on coral reef systems.

  14. Effects of water deficit stress, shade, weed competition, and kaolin particle film on selected foliar free amino acid accumulations in cotton, Gossypium hirsutum (L.).

    PubMed

    Showler, Allan T

    2002-03-01

    Leaves of cotton plants, Gossypium hirsutum L., stressed by water deficit, reduced daylight, and weed competition, or treated with a kaolin wettable powder formulation were analyzed for levels of 17 free amino acids (FAAs) using reversed-phase high-performance liquid chromatography. Water deficit stress resulted in heightened free proline levels (49.9-fold, P < 0.001) that were correlated with diffusive resistance (seconds per centimeter). Five other FAAs increased, and the amounts of total free essential (for insect growth and development) amino acids and total FAAs also increased (P < or = 0.05). Cotton grown in 50% shade accumulated significantly more free arginine than control plants. In a small-plot weed competition assay, four FAAs increased and three FAAs decreased in association with weed competition, but because free proline levels were not altered and free arginine levels increased, other stresses aside from water deficit, possibly including shading by tall weeds, appear to have caused the changes. In a small-plot kaolin particle film assay, five FAAs were lower in cotton foliage sprayed weekly with kaolin. Because free proline was unaffected and free arginine was lower, it is possible that kaolin's reflectivity heightened light reception. The responses of free proline and arginine to the treatments used in these assays demonstrate that types and degrees of some stresses to cotton can be characterized by accumulations of certain FAAs. The study also demonstrates how some FAA levels can indicate degrees of cotton stress resulting from weed competition and from kaolin particle film application. Porometry and leaf water potential measurements assisted in corroborating some findings of the study.

  15. 1α,25-dihydroxyvitamin D inhibits de novo fatty acid synthesis and lipid accumulation in metastatic breast cancer cells through down-regulation of pyruvate carboxylase.

    PubMed

    Wilmanski, Tomasz; Buhman, Kimberly; Donkin, Shawn S; Burgess, John R; Teegarden, Dorothy

    2017-02-01

    Both increased de novo fatty acid synthesis and higher neutral lipid accumulation are a common phenotype observed in aggressive breast cancer cells, making lipid metabolism a promising target for breast cancer prevention. In the present studies, we demonstrate a novel effect of the active metabolite of vitamin D, 1α,25-dihydroxyvitamin D (1,25(OH)₂D) on lipid metabolism in malignant breast epithelial cells. Treatment of MCF10CA1a breast epithelial cells with 1,25(OH)₂D (10 nM) for 5 and 7 days decreased the level of triacylglycerol, the most abundant form of neutral lipids, by 20%(±3.9) and 50%(±5.9), respectively. In addition, 1,25(OH)₂D treatment for 5 days decreased palmitate synthesis from glucose, the major fatty acid synthesized de novo (48%±5.5 relative to vehicle). We have further identified the anaplerotic enzyme pyruvate carboxylase (PC) as a target of 1,25(OH)₂D-mediated regulation and hypothesized that 1,25(OH)₂D regulates breast cancer cell lipid metabolism through inhibition of PC. PC mRNA expression was down-regulated with 1,25(OH)₂D treatment at 2 (73%±6 relative to vehicle) and 5 (56%±8 relative to vehicle) days. Decrease in mRNA abundance corresponded with a decrease in PC protein expression at 5 days of treatment (54%±12 relative to vehicle). Constitutive overexpression of PC in MCF10CA1a cells using a pCMV6-PC plasmid inhibited the effect of 1,25(OH)₂D on both TAG accumulation and de novo palmitate synthesis from glucose. Together, these studies demonstrate a novel mechanism through which 1,25(OH)₂D regulates lipid metabolism in malignant breast epithelial cells.

  16. Effects of microalgal polyunsaturated fatty acid oil on body weight and lipid accumulation in the liver of C57BL/6 mice fed a high fat diet

    PubMed Central

    Go, Ryeo-Eun; Hwang, Kyung-A; Park, Geon-Tae; Lee, Hae-Miru; Lee, Geum-A; Kim, Cho-Won; Jeon, So-Ye; Seo, Jeong-Woo; Hong, Won-Kyung; Choi, Kyung-Chul

    2016-01-01

    Abstract Dietary polyunsaturated fatty acids (PUFAs), which are abundant in marine fish oils, have recently received global attention for their prominent anti-obesogenic effects. Among PUFAs, eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3), which are n-3 long-chain PUFAs widely referred to as omega-3 oils, were reported to prevent the development of obesity in rodents and humans. In the present study, we evaluated the anti-obesity effects of microalgal oil on high-fat induced obese C57BL/6 mice, compared with commercial omega-3 fish oil and vegetable corn oil. Microalgal oil is an inherent mixture of several PUFAs, including EPA, DHA and other fatty acids produced from a marine microalgal strain of Thraustochytriidae sp. derived mutant. It was found to contain more PUFAs (>80%) and more omega-3 oils than commercial omega-3 fish oil (PUFAs >31%) and corn oil (PUFAs 59%). All three types of oils induced weight loss in high-fat-induced obese mice, with the loss induced by microalgal oil being most significant at 9 weeks (10% reduction). However, the oils tested did not improve blood lipid levels, although microalgal oil showed an apparent inhibitory effect on lipid accumulation in the liver. These findings may be attributed to the higher PUFA content, including omega-3 oils of microalgal oil than other oils. Collectively, these findings suggest that microalgal oil, derived from Thraustochytriidae sp. derived mutant, is a prominent candidate for replacement of omega-3 fish oils based on its apparent anti-obesity effect in vivo. PMID:27533934

  17. Identification of target genes and processes involved in erucic acid accumulation during seed development in the biodiesel feedstock Pennycress (Thlaspi arvense L.).

    PubMed

    Claver, Ana; Rey, Raquel; López, M Victoria; Picorel, Rafael; Alfonso, Miguel

    2017-01-01

    We studied erucic acid accumulation in the biodiesel feedstock Pennycress (Thlaspi arvense L.) as a first step towards the development of a sustainable strategy for biofuel production in the EU territory. To that end, two inbred Pennycress lines of European origin, "NASC" and "French," were cultivated in a controlled chamber and in experimental field plots, and their growth, seed production and seed oil characteristics analyzed. Differences in some agronomical traits like vernalization (winter-French versus spring-NASC), flowering time (delayed in the French line) and seed production (higher in the French line) were detected. Both lines showed a high amount (35-39%) of erucic acid (22:1(Δ13)) in their seed oil. Biochemical characterization of the Pennycress seed oil indicated that TAG was the major reservoir of 22:1(Δ13). Incorporation of 22:1(Δ13) to TAG occurred very early during seed maturation, concomitant with a decrease of desaturase activity. This change in the acyl fluxes towards elongation was controlled by different genes at different levels. TaFAE1 gene, encoding the fatty acid elongase, seemed to be controlled at the transcriptional level with high expression at the early stages of seed development. On the contrary, the TaFAD2 gene that encodes the Δ12 fatty acid desaturase or TaDGAT1 that catalyzes TAG biosynthesis were controlled post-transcriptionally. TaWRI1, the master regulator of seed-oil biosynthesis, showed also high expression at the early stages of seed development. Our data identified genes and processes that might improve the biotechnological manipulation of Pennycress seeds for high-quality biodiesel production.

  18. Similar PAH Fate in Anaerobic Digesters Inoculated with Three Microbial Communities Accumulating Either Volatile Fatty Acids or Methane

    PubMed Central

    Braun, Florence; Hamelin, Jérôme; Bonnafous, Anaïs; Delgenès, Nadine; Steyer, Jean-Philippe; Patureau, Dominique

    2015-01-01

    Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH). Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA) production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR), in community structure (SSCP fingerprinting) and in dominant microbial species (454-pyrosequencing). The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10 % to 30 %, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm that PAH

  19. Similar PAH fate in anaerobic digesters inoculated with three microbial communities accumulating either volatile fatty acids or methane.

    PubMed

    Braun, Florence; Hamelin, Jérôme; Bonnafous, Anaïs; Delgenès, Nadine; Steyer, Jean-Philippe; Patureau, Dominique

    2015-01-01

    Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH). Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA) production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR), in community structure (SSCP fingerprinting) and in dominant microbial species (454-pyrosequencing). The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10% to 30%, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm that PAH removal

  20. Nicotiana attenuata SIPK, WIPK, NPR1, and Fatty Acid-Amino Acid Conjugates Participate in the Induction of Jasmonic Acid Biosynthesis by Affecting Early Enzymatic Steps in the Pathway1[W][OA

    PubMed Central

    Kallenbach, Mario; Alagna, Fiammetta; Baldwin, Ian Thomas; Bonaventure, Gustavo

    2010-01-01

    Wounding and herbivore attack elicit the rapid (within minutes) accumulation of jasmonic acid (JA) that results from the activation of previously synthesized biosynthetic enzymes. Recently, several regulatory factors that affect JA production have been identified; however, how these regulators affect JA biosynthesis remains at present unknown. Here we demonstrate that Nicotiana attenuata salicylate-induced protein kinase (SIPK), wound-induced protein kinase (WIPK), nonexpressor of PR-1 (NPR1), and the insect elicitor N-linolenoyl-glucose (18:3-Glu) participate in mechanisms affecting early enzymatic steps of the JA biosynthesis pathway. Plants silenced in the expression of SIPK and NPR1 were affected in the initial accumulation of 13-hydroperoxy-linolenic acid (13-OOH-18:3) after wounding and 18:3-Glu elicitation by mechanisms independent of changes in 13-lipoxygenase activity. Moreover, 18:3-Glu elicited an enhanced and rapid accumulation of 13-OOH-18:3 that depended partially on SIPK and NPR1 but was independent of increased 13-lipoxygenase activity. Together, the results suggested that substrate supply for JA production was altered by 18:3-Glu elicitation and SIPK- and NPR1-mediated mechanisms. Consistent with a regulation at the level of substrate supply, we demonstrated by virus-induced gene silencing that a wound-repressed plastidial glycerolipase (NaGLA1) plays an essential role in the induction of de novo JA biosynthesis. In contrast to SIPK and NPR1, mechanisms mediated by WIPK did not affect the production of 13-OOH-18:3 but were critical to control the conversion of this precursor into 12-oxo-phytodienoic acid. These differences could be partially accounted for by reduced allene oxide synthase activity in WIPK-silenced plants. PMID:19897603

  1. Effect of temperature on short chain fatty acids (SCFAs) accumulation and microbiological transformation in sludge alkaline fermentation with Ca(OH)₂ adjustment.

    PubMed

    Li, XiaoLing; Peng, YongZhen; Ren, NanQi; Li, BaiKun; Chai, TongZhi; Zhang, Liang

    2014-09-15

    The effects of temperatures (15-55 °C) on the alkaline fermentation of sewage sludge were investigated in semi-continuous stirred tank reactors (semi - CSTR) at the pH of 10. The highest soluble chemical oxygen demand (SCOD) yield was obtained at 55 °C (764.2 mg/(gVS L d)), while the highest short chain fatty acids (SCFAs) yield was observed at 35 °C (319.8 mg/(gVS L d)), 1.5 times higher than SCFAs yield at 55 °C (209.5 mg/(gVS L d)). The proportion of the intercellular organic substances being transferred to the slime layer of sludge flocs increased from 29% at 15 °C to 54% at 55 °C. But only a small part of soluble organic substances in the slime layers was converted to SCFAs at 55 °C. The dewaterability of sludge was better at 35 °C than that at 55 °C. Microbiological community analysis showed the acid-producing microorganisms at the medium temperatures (25 °C and 35 °C) were more diverse and abundant than those at the low (15 °C) and high temperatures (55 °C). Clodtridium and Bacillus in Firmicutes and Gamma proteobacterium in Proteobacteria were the dominant functional bacterial species for high SCFA accumulation.

  2. Disturbance of mitochondrial functions provoked by the major long-chain 3-hydroxylated fatty acids accumulating in MTP and LCHAD deficiencies in skeletal muscle.

    PubMed

    Cecatto, Cristiane; Godoy, Kálita Dos Santos; da Silva, Janaína Camacho; Amaral, Alexandre Umpierrez; Wajner, Moacir

    2016-10-01

    The pathogenesis of the muscular symptoms and recurrent rhabdomyolysis that are commonly manifested in patients with mitochondrial trifunctional protein (MTP) and long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) deficiencies is still unknown. In this study we investigated the effects of the major long-chain monocarboxylic 3-hydroxylated fatty acids (LCHFA) accumulating in these disorders, namely 3-hydroxytetradecanoic (3HTA) and 3-hydroxypalmitic (3HPA) acids, on important mitochondrial functions in rat skeletal muscle mitochondria. 3HTA and 3HPA markedly increased resting (state 4) and decreased ADP-stimulated (state 3) and CCCP-stimulated (uncoupled) respiration. 3HPA provoked similar effects in permeabilized skeletal muscle fibers, validating the results obtained in purified mitochondria. Furthermore, 3HTA and 3HPA markedly diminished mitochondrial membrane potential, NAD(P)H content and Ca(2+) retention capacity in Ca(2+)-loaded mitochondria. Mitochondrial permeability transition (mPT) induction probably underlie these effects since they were totally prevented by cyclosporin A and ADP. In contrast, the dicarboxylic analogue of 3HTA did not alter the tested parameters. Our data strongly indicate that 3HTA and 3HPA behave as metabolic inhibitors, uncouplers of oxidative phosphorylation and mPT inducers in skeletal muscle. It is proposed that these pathomechanisms disrupting mitochondrial homeostasis may be involved in the muscle alterations characteristic of MTP and LCHAD deficiencies.

  3. Salicylic Acid Suppresses Jasmonic Acid Signaling Downstream of SCFCOI1-JAZ by Targeting GCC Promoter Motifs via Transcription Factor ORA59[C][W][OA

    PubMed Central

    Van der Does, Dieuwertje; Leon-Reyes, Antonio; Koornneef, Annemart; Van Verk, Marcel C.; Rodenburg, Nicole; Pauwels, Laurens; Goossens, Alain; Körbes, Ana P.; Memelink, Johan; Ritsema, Tita; Van Wees, Saskia C.M.; Pieterse, Corné M.J.

    2013-01-01

    Antagonism between the defense hormones salicylic acid (SA) and jasmonic acid (JA) plays a central role in the modulation of the plant immune signaling network, but the molecular mechanisms underlying this phenomenon are largely unknown. Here, we demonstrate that suppression of the JA pathway by SA functions downstream of the E3 ubiquitin-ligase Skip-Cullin-F-box complex SCFCOI1, which targets JASMONATE ZIM-domain transcriptional repressor proteins (JAZs) for proteasome-mediated degradation. In addition, neither the stability nor the JA-induced degradation of JAZs was affected by SA. In silico promoter analysis of the SA/JA crosstalk transcriptome revealed that the 1-kb promoter regions of JA-responsive genes that are suppressed by SA are significantly enriched in the JA-responsive GCC-box motifs. Using GCC:GUS lines carrying four copies of the GCC-box fused to the β-glucuronidase reporter gene, we showed that the GCC-box motif is sufficient for SA-mediated suppression of JA-responsive gene expression. Using plants overexpressing the GCC-box binding APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factors ERF1 or ORA59, we found that SA strongly reduces the accumulation of ORA59 but not that of ERF1. Collectively, these data indicate that the SA pathway inhibits JA signaling downstream of the SCFCOI1-JAZ complex by targeting GCC-box motifs in JA-responsive promoters via a negative effect on the transcriptional activator ORA59. PMID:23435661

  4. Methyl Jasmonate Regulates Podophyllotoxin Accumulation in Podophyllum hexandrum by Altering the ROS-Responsive Podophyllotoxin Pathway Gene Expression Additionally through the Down Regulation of Few Interfering miRNAs.

    PubMed

    Hazra, Saptarshi; Bhattacharyya, Dipto; Chattopadhyay, Sharmila

    2017-01-01

    Podophylloxin (ptox), primarily obtained from Podophyllum hexandrum, is the precursor for semi-synthetic anticancer drugs viz. etoposide, etopophos, and teniposide. Previous studies established that methyl jasmonate (MeJA) treated cell culture of P. hexandrum accumulate ptox significantly. However, the molecular mechanism of MeJA induced ptox accumulation is yet to be explored. Here, we demonstrate that MeJA induces reactive oxygen species (ROS) production, which stimulates ptox accumulation significantly and up regulates three ROS-responsive ptox biosynthetic genes, namely, PhCAD3, PhCAD4 (cinnamyl alcohol dehydrogenase), and NAC3 by increasing their mRNA stability. Classic uncoupler of oxidative phosphorylation, carbonylcyanide m-chlorophenylhydrazone, as well as H2O2 treatment induced the ROS generation and consequently, enhanced the ptox production. However, when the ROS was inhibited with NADPH oxidase inhibitor diphenylene iodonium and Superoxide dismutase inhibitor diethyldithio-carbamic acid, the ROS inhibiting agent, the ptox production was decreased significantly. We also noted that, MeJA up regulated other ptox biosynthetic pathway genes which are not affected by the MeJA induced ROS. Further, these ROS non-responsive genes were controlled by MeJA through the down regulation of five secondary metabolites biosynthesis specific miRNAs viz. miR172i, miR035, miR1438, miR2275, and miR8291. Finally, this study suggested two possible mechanisms through which MeJA modulates the ptox biosynthesis: primarily by increasing the mRNA stability of ROS-responsive genes and secondly, by the up regulation of ROS non-responsive genes through the down regulation of some ROS non-responsive miRNAs.

  5. Methyl Jasmonate Regulates Podophyllotoxin Accumulation in Podophyllum hexandrum by Altering the ROS-Responsive Podophyllotoxin Pathway Gene Expression Additionally through the Down Regulation of Few Interfering miRNAs

    PubMed Central

    Hazra, Saptarshi; Bhattacharyya, Dipto; Chattopadhyay, Sharmila

    2017-01-01

    Podophylloxin (ptox), primarily obtained from Podophyllum hexandrum, is the precursor for semi-synthetic anticancer drugs viz. etoposide, etopophos, and teniposide. Previous studies established that methyl jasmonate (MeJA) treated cell culture of P. hexandrum accumulate ptox significantly. However, the molecular mechanism of MeJA induced ptox accumulation is yet to be explored. Here, we demonstrate that MeJA induces reactive oxygen species (ROS) production, which stimulates ptox accumulation significantly and up regulates three ROS-responsive ptox biosynthetic genes, namely, PhCAD3, PhCAD4 (cinnamyl alcohol dehydrogenase), and NAC3 by increasing their mRNA stability. Classic uncoupler of oxidative phosphorylation, carbonylcyanide m-chlorophenylhydrazone, as well as H2O2 treatment induced the ROS generation and consequently, enhanced the ptox production. However, when the ROS was inhibited with NADPH oxidase inhibitor diphenylene iodonium and Superoxide dismutase inhibitor diethyldithio-carbamic acid, the ROS inhibiting agent, the ptox production was decreased significantly. We also noted that, MeJA up regulated other ptox biosynthetic pathway genes which are not affected by the MeJA induced ROS. Further, these ROS non-responsive genes were controlled by MeJA through the down regulation of five secondary metabolites biosynthesis specific miRNAs viz. miR172i, miR035, miR1438, miR2275, and miR8291. Finally, this study suggested two possible mechanisms through which MeJA modulates the ptox biosynthesis: primarily by increasing the mRNA stability of ROS-responsive genes and secondly, by the up regulation of ROS non-responsive genes through the down regulation of some ROS non-responsive miRNAs. PMID:28261233

  6. Intake of a Western diet containing cod instead of pork alters fatty acid composition in tissue phospholipids and attenuates obesity and hepatic lipid accumulation in mice.

    PubMed

    Liisberg, Ulrike; Fauske, Kristin Røen; Kuda, Ondrej; Fjære, Even; Myrmel, Lene Secher; Norberg, Nina; Frøyland, Livar; Graff, Ingvild Eide; Liaset, Bjørn; Kristiansen, Karsten; Kopecky, Jan; Madsen, Lise

    2016-07-01

    The content of the marine n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is far lower in lean than in fatty seafood. Cod filets contain less than 2g fat per kg, whereof approximately 50% is EPA and DHA. However, a large fraction of these n-3 PUFAs is present in the phospholipid (PL) fraction and may have high bioavailability and capacity to change the endocannabinoid profile. Here we investigated whether exchanging meat from a lean terrestrial animal with cod in a background Western diet would alter the endocannabinoid tone in mice and thereby attenuate obesity development and hepatic lipid accumulation. Accordingly, we prepared iso-caloric diets with 15.1 energy (e) % protein, 39.1 e% fat and 45.8 e% carbohydrates using freeze-dried meat from cod filets or pork sirloins, and using a combination of soybean oil, corn oil, margarine, milk fat, and lard as the fat source. Compared with mice receiving diets containing pork, mice fed cod gained less adipose tissue mass and had a lower content of hepatic lipids. This was accompanied by a lower n-6 to n-3 ratio in liver PLs and in red blood cells (RBCs) in the mice. Furthermore, mice receiving the cod-containing diet had lower circulating levels of the two major endocannabinoids, N-arachidonoylethanolamine and 2-arachidonoylglycerol. Together, our data demonstrate that despite the relatively low content of n-3 PUFAs in cod fillets, the cod-containing diet could exert beneficial metabolic effects.

  7. Accumulation of trans C18:1 fatty acids in the rumen after dietary algal supplementation is associated with changes in the Butyrivibrio community.

    PubMed

    Boeckaert, Charlotte; Vlaeminck, Bruno; Fievez, Veerle; Maignien, Lois; Dijkstra, Jan; Boon, Nico

    2008-11-01

    Optimization of the fatty acid composition of ruminant milk and meat is desirable. Dietary supplementation of algae was previously shown to inhibit rumen biohydrogenation, resulting in an altered milk fatty acid profile. Bacteria involved in biohydrogenation belong to the Butyrivibrio group. This study was aimed at relating accumulation of biohydrogenation intermediates with shifts in Butyrivibrio spp. in the rumen of dairy cows. Therefore, an experiment was performed with three rumen-fistulated dairy cows receiving a concentrate containing algae (9.35 g/kg total dry matter [DM] intake) for 20 days. Supplementation of the diet with algae inhibited biohydrogenation of C(18:2) omega 6 (n-6) and C(18:3) n-3, resulting in increased concentrations of biohydrogenation intermediates, whereas C(18:0) decreased. Addition of algae increased ruminal C(18:1) trans fatty acid concentrations, mainly due to 6- and 20-fold increases in C(18:1) trans 11 (t11) and C(18:1) t10. The number of ciliates (5.37 log copies/g rumen digesta) and the composition of the ciliate community were unaffected by dietary algae. In contrast, supplementation of the diet with algae changed the composition of the bacterial community. Primers for the Butyrivibrio group, including the genera Butyrivibrio and Pseudobutyrivibrio, were specifically designed. Denaturing gradient gel electrophoresis showed community changes upon addition of algae without affecting the total amount of Butyrivibrio bacteria (7.06 log copies/g rumen DM). Clone libraries showed that algae affected noncultivated species, which cluster taxonomically between the genera Butyrivibrio and Pseudobutyrivibrio and might play a role in biohydrogenation. In addition, 20% of the clones from a randomly selected rumen sample were related to the C(18:0)-producing branch, although the associated C(18:0) concentration decreased through supplementation of the diet with algae.

  8. Suppression of γ-aminobutyric acid (GABA) transaminases induces prominent GABA accumulation, dwarfism and infertility in the tomato (Solanum lycopersicum L.).

    PubMed

    Koike, Satoshi; Matsukura, Chiaki; Takayama, Mariko; Asamizu, Erika; Ezura, Hiroshi

    2013-05-01

    Tomatoes accumulate γ-aminobutyric acid (GABA) at high levels in the immature fruits. GABA is rapidly converted to succinate during fruit ripening through the activities of GABA transaminase (GABA-T) and succinate semialdehyde dehydrogenase (SSADH). Although three genes encoding GABA-T and both pyruvate- and α-ketoglutarate-dependent GABA-T activities have been detected in tomato fruits, the mechanism underlying the GABA-T-mediated conversion of GABA has not been fully understood. In this work, we conducted loss-of-function analyses utilizing RNA interference (RNAi) transgenic plants with suppressed pyruvate- and glyoxylate-dependent GABA-T gene expression to clarify which GABA-T isoforms are essential for its function. The RNAi plants with suppressed SlGABA-T gene expression, particularly SlGABA-T1, showed severe dwarfism and infertility. SlGABA-T1 expression was inversely associated with GABA levels in the fruit at the red ripe stage. The GABA contents in 35S::SlGABA-T1(RNAi) lines were 1.3-2.0 times and 6.8-9.2 times higher in mature green and red ripe fruits, respectively, than the contents in wild-type fruits. In addition, SlGABA-T1 expression was strongly suppressed in the GABA-accumulating lines. These results indicate that pyruvate- and glyoxylate-dependent GABA-T is the essential isoform for GABA metabolism in tomato plants and that GABA-T1 primarily contributes to GABA reduction in the ripening fruits.

  9. Effect of diacylglycerol acyltransferase 2 overexpression in 3T3-L1 is associated to an increase in mono-unsaturated fatty acid accumulation

    PubMed Central

    2014-01-01

    Background Fatty acid (FA) composition is the most important parameter affecting the flavor and nutritional value of the meat. The final and the only committed step in the biosynthesis of triglycerides is catalyzed by diacylglycerol acyltransferase 2 (DGAT2). The role of DGAT2 in lipid accumulation has been demonstrated in adipocytes, However, little is known about the effect of DGAT2 on the FA composition of these cells. Methods To investigate the role of DGAT2 in regulating lipid accumulation, FA composition and the expression of adipogenic genes, we cloned the open reading frame of the porcine DGAT2 gene and established 3T3-L1 cells that overexpressed DGAT2. Cells were then cultured in differentiation medium (DM) without FA, with a mixture of FAs (FA-DM), or containing a 13C stable isotope-labeled FA mixture (IFA-DM). The FA composition of adipocytes was analyzed by gas chromatography–mass spectrometry and gas chromatography-isotope ratio mass spectrometry. Quantitative PCR and western blotting were employed to detect expression of adipogenic genes in 3T3-L1 adipocytes cultured with FA-DM for 12 d. Results The triacylglyceride (TAG) content was significantly higher in 3T3-L1 adipocytes overexpressing DGAT2 than in control cells. When cultured in DM or FA-DM for 12 d, cells overexpressing DGAT2 showed a higher proportion of unsaturated FAs (C16:1 and C18:1). However, when cells overexpressing DGAT2 were cultured with FA-DM for 30 min, the FA composition was almost identical to that of controls. Further, the proportion of stable isotope-labeled FAs were similar in 3T3-L1 adipocytes overexpressing DGAT2 and control cells cultured in IFA-DM for 12 d. These results collectively indicate that the higher proportion of mono-unsaturated FAs, C16:1 and C18:1, may originate from de novo FA synthesis but not from the uptake of specific FAs from the medium. This hypothesis is further supported by evidence that both mRNA and protein expression of genes involved in FA

  10. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  11. Defense activation triggers differential expression of phospholipase-C (PLC) genes and elevated temperature induces phosphatidic acid (PA) accumulation in tomato

    PubMed Central

    Abd-El-Haliem, Ahmed; Meijer, Harold J.G.; Tameling, Wladimir I.L.; Vossen, Jack H.; Joosten, Matthieu H.A.J.

    2012-01-01

    Recently, we provided the first genetic evidence for the requirement of tomato PLC4 and PLC6 genes in defense activation and disease resistance. The encoded enzymes were catalytically active as they were able to degrade phosphatidylinositol (PI), thereby producing diacylglycerol (DG). Here we report differential PLC gene expression following the initiation of defense signaling by the interaction between Cladosporium fulvum resistance (R) protein Cf-4 and its matching effector Avr4 in tomato hybrid seedlings that express both Cf-4 and Avr4. Furthermore, we observed that PLC3 and PLC6 gene expression is upregulated by elevated temperature in the control seedlings. This upregulation coincides with an increase in the levels of phosphatidic acid (PA) and a decrease in the levels of PI and phosphatidylinositol phosphate (PIP). The decrease in PI and PIP levels matches with the activation of PLC. In addition, the levels of the structural phospholipids phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) declined transiently during recovery after the exposure to elevated temperature., Further studies will be required to explain the mechanism causing the sustained accumulation of PA during recovery, combined with a reduction in the levels of structural phospholipids. PMID:22899083

  12. Delayed uric Acid accumulation in plasma provides additional anti-oxidant protection against iron-triggered oxidative stress after a wingate test.

    PubMed

    Souza-Junior, Tp; Lorenço-Lima, L; Ganini, D; Vardaris, Cv; Polotow, Tg; Barros, Mp

    2014-12-01

    Reactive oxygen species are produced during anaerobic exercise mostly by Fe ions released into plasma and endothelial/muscle xanthine oxidase activation that generates uric acid (UA) as the endpoint metabolite. Paradoxically, UA is considered a major antioxidant by virtue of being able to chelate pro-oxidative iron ions. This work aimed to evaluate the relationship between UA and plasma markers of oxidative stress following the exhaustive Wingate test. Plasma samples of 17 male undergraduate students were collected before, 5 and 60 min after maximal anaerobic effort for the measurement of total iron, haem iron, UA, ferric-reducing antioxidant activity in plasma (FRAP), and malondialdehyde (MDA, biomarker of lipoperoxidation). Iron and FRAP showed similar kinetics in plasma, demonstrating an adequate pro-/antioxidant balance immediately after exercise and during the recovery period (5-60 min). Slight variations of haem iron concentrations did not support a relevant contribution of rhabdomyolysis or haemolysis for iron overload following exercise. UA concentration did not vary immediately after exercise but rather increased 29% during the recovery period. Unaltered MDA levels were concomitantly measured. We propose that delayed UA accumulation in plasma is an auxiliary antioxidant response to post-exercise (iron-mediated) oxidative stress, and the high correlation between total UA and FRAP in plasma (R-Square = 0.636; p = 0.00582) supports this hypothesis.

  13. Arachidonic acid alters tomato HMG expression and fruit growth and induces 3-hydroxy-3-methylglutaryl coenzyme A reductase-independent lycopene accumulation

    SciTech Connect

    Rodriguez-Concepcion, M.; Gruissem, W.

    1999-01-01

    Regulation of isoprenoid end-product synthesis required for normal growth and development in plants is not well understood. To investigate the extent to which specific genes for the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) are involved in end-product regulation, the authors manipulated expression of the HMG1 and HMG2 genes in tomato (Lycopersicon esculentum) fruit using arachidonic acid (AA). In developing young fruit AA blocked fruit growth, inhibited HMG1, and activated HMG2 expression. These results are consistent with other reports indicating that HMG1 expression is closely correlated with growth processes requiring phytosterol production. In mature-green fruit AA strongly induced the expression of HMG2, PSY1 (the gene for phytoene synthase), and lycopene accumulation before the normal onset of carotenoid synthesis and ripening. The induction of lycopene synthesis was not blocked by inhibition of HMGR activity using mevinolin, suggesting that cytoplasmic HMGR is not required for carotenoid synthesis. Their results are consistent with the function of an alternative plastid isoprenoid pathway (the Rohmer pathway) that appears to direct the production of carotenoids during tomato fruit ripening.

  14. Enhanced Photosynthesis and Growth in atquac1 Knockout Mutants Are Due to Altered Organic Acid Accumulation and an Increase in Both Stomatal and Mesophyll Conductance1

    PubMed Central

    Martins, Samuel C.V.; Daloso, Danilo M.; Martinoia, Enrico; Nunes-Nesi, Adriano; DaMatta, Fábio M.; Fernie, Alisdair R.; Araújo, Wagner L.

    2016-01-01

    Stomata control the exchange of CO2 and water vapor in land plants. Thus, whereas a constant supply of CO2 is required to maintain adequate rates of photosynthesis, the accompanying water losses must be tightly regulated to prevent dehydration and undesired metabolic changes. Accordingly, the uptake or release of ions and metabolites from guard cells is necessary to achieve normal stomatal function. The AtQUAC1, an R-type anion channel responsible for the release of malate from guard cells, is essential for efficient stomatal closure. Here, we demonstrate that mutant plants lacking AtQUAC1 accumulated higher levels of malate and fumarate. These mutant plants not only display slower stomatal closure in response to increased CO2 concentration and dark but are also characterized by improved mesophyll conductance. These responses were accompanied by increases in both photosynthesis and respiration rates, without affecting the activity of photosynthetic and respiratory enzymes and the expression of other transporter genes in guard cells, which ultimately led to improved growth. Collectively, our results highlight that the transport of organic acids plays a key role in plant cell metabolism and demonstrate that AtQUAC1 reduce diffusive limitations to photosynthesis, which, at least partially, explain the observed increments in growth under well-watered conditions. PMID:26542441

  15. Accumulation of Zeaxanthin in Abscisic Acid-Deficient Mutants of Arabidopsis Does Not Affect Chlorophyll Fluorescence Quenching or Sensitivity to Photoinhibition in Vivo.

    PubMed Central

    Hurry, V.; Anderson, J. M.; Chow, W. S.; Osmond, C. B.

    1997-01-01

    Abscisic acid (ABA)-deficient mutants of Arabidopsis do not synthesize the epoxy-xanthophylls antheraxanthin, violaxanthin, or neoxanthin. However, thylakoid membranes from these mutants contain 3-fold more zeaxanthin than wild-type plants. This increase in zeaxanthin occurs as a stoichiometric replacement of the missing violaxanthin and neoxanthin within the pigment-protein complexes of both photosystem I and photosystem II (PSII). The retention of zeaxanthin in the dark by ABA-deficient mutants sensitizes the leaves to the development of nonphotochemical quenching (NPQ) during the first 2 to 4 min following a dark-light transition. However, the increase in pool size does not result in any increase in steady-state NPQ. When we exposed wild-type and ABA-deficient mutants leaves to twice growth irradiance, the mutants developed lower maximal NPQ but suffered similar photoinhibition to wildtype, measured both as a decline in the ratio of variable to maximal fluorescence and as a loss of functional PSII centers from oxygen flash yield measurements. These results suggest that only a few of the zeaxanthin molecules present within the light-harvesting antenna of PSII may be involved in NPQ and neither the accumulation of a large pool of zeaxanthin within the antenna of PSII nor an increase in conversion of violaxanthin to zeaxanthin will necessarily enhance photoprotective energy dissipation. PMID:12223632

  16. Spontaneously Occurring Formation of Intranuclear and Cytoplasmic Inclusions in Renal Proximal Epithelium Due to Accumulation of D-Amino Acid Oxidase in Wistar Hannover Rats.

    PubMed

    Shimoyama, Natsumi; Nakatsuji, Shunji; Andoh, Rie; Yamaguchi, Yuko; Tamura, Kazutoshi; Hoshiya, Toru

    2015-07-01

    Intranuclear and cytoplasmic inclusions in the renal proximal tubular epithelium were observed in nontreated male and female Wistar Hannover rats in a 26-week study (32 weeks of age) and a 104-week study (110 weeks of age). The incidence rates were less than 5% in these two studies. In affected animals, the inclusions were observed in more than 60% of proximal tubular epithelium as various sized (approximately 1-8 μm in diameter) round and eosinophilic materials, but not in distal tubules, Henle's loop, or collecting ducts. Ultrastructurally, inclusions appeared finely granular, homogenous with middle-electron density, and without a limiting membrane. These inclusions were determined to be protein histochemically stained by Azan-Mallory and immunoreactive with an antibody against D-amino acid oxidase (DAO). There was no abnormality in in-life observations or in clinical test values suggestive of renal dysfunction. There were no associated degenerative or inflammatory changes in the kidneys, and no similar inclusions were observed in the other organs. These inclusions are very similar to propiverine hydrochloride (propiverine) and norepinephreine/serotonin reuptake inhibitor-induced inclusions. This is the first report of accumulation of DAO and formation of inclusions occurring spontaneously in rat kidneys. The data are important for toxicological studies using Wistar Hannover rats.

  17. Ezetimibe markedly attenuates hepatic cholesterol accumulation and improves liver function in the lysosomal acid lipase-deficient mouse, a model for cholesteryl ester storage disease.

    PubMed

    Chuang, Jen-Chieh; Lopez, Adam M; Posey, Kenneth S; Turley, Stephen D

    2014-01-17

    Lysosomal acid lipase (LAL) plays a critical role in the intracellular handling of lipids by hydrolyzing cholesteryl esters (CE) and triacylglycerols (TAG) contained in newly internalized lipoproteins. In humans, mutations in the LAL gene result in cholesteryl ester storage disease (CESD), or in Wolman disease (WD) when the mutations cause complete loss of LAL activity. A rat model for WD and a mouse model for CESD have been described. In these studies we used LAL-deficient mice to investigate how modulating the amount of intestinally-derived cholesterol reaching the liver might impact its mass, cholesterol content, and function in this model. The main experiment tested if ezetimibe, a potent cholesterol absorption inhibitor, had any effect on CE accumulation in mice lacking LAL. In male Lal(-/-) mice given ezetimibe in their diet (20 mg/day/kg bw) for 4 weeks starting at 21 days of age, both liver mass and hepatic cholesterol concentration (mg/g) were reduced to the extent that whole-liver cholesterol content (mg/organ) in the treated mice (74.3±3.4) was only 56% of that in those not given ezetimibe (133.5±6.7). There was also a marked improvement in plasma alanine aminotransferase (ALT) activity. Thus, minimizing cholesterol absorption has a favorable impact on the liver in CESD.

  18. DELAYED URIC ACID ACCUMULATION IN PLASMA PROVIDES ADDITIONAL ANTI-OXIDANT PROTECTION AGAINST IRON-TRIGGERED OXIDATIVE STRESS AFTER A WINGATE TEST

    PubMed Central

    Souza-Junior, TP; Lorenço-Lima, L; Ganini, D; Vardaris, CV; Polotow, TG

    2014-01-01

    Reactive oxygen species are produced during anaerobic exercise mostly by Fe ions released into plasma and endothelial/muscle xanthine oxidase activation that generates uric acid (UA) as the endpoint metabolite. Paradoxically, UA is considered a major antioxidant by virtue of being able to chelate pro-oxidative iron ions. This work aimed to evaluate the relationship between UA and plasma markers of oxidative stress following the exhaustive Wingate test. Plasma samples of 17 male undergraduate students were collected before, 5 and 60 min after maximal anaerobic effort for the measurement of total iron, haem iron, UA, ferric-reducing antioxidant activity in plasma (FRAP), and malondialdehyde (MDA, biomarker of lipoperoxidation). Iron and FRAP showed similar kinetics in plasma, demonstrating an adequate pro-/antioxidant balance immediately after exercise and during the recovery period (5–60 min). Slight variations of haem iron concentrations did not support a relevant contribution of rhabdomyolysis or haemolysis for iron overload following exercise. UA concentration did not vary immediately after exercise but rather increased 29% during the recovery period. Unaltered MDA levels were concomitantly measured. We propose that delayed UA accumulation in plasma is an auxiliary antioxidant response to post-exercise (iron-mediated) oxidative stress, and the high correlation between total UA and FRAP in plasma (R-Square = 0.636; p = 0.00582) supports this hypothesis. PMID:25435669

  19. Lysophosphatidic acid mediates the rapid activation of platelets and endothelial cells by mildly oxidized low density lipoprotein and accumulates in human atherosclerotic lesions.

    PubMed

    Siess, W; Zangl, K J; Essler, M; Bauer, M; Brandl, R; Corrinth, C; Bittman, R; Tigyi, G; Aepfelbacher, M

    1999-06-08

    Oxidized low density lipoprotein (LDL) is a key factor in the pathogenesis of atherosclerosis and its thrombotic complications, such as stroke and myocardial infarction. It activates endothelial cells and platelets through mechanisms that are largely unknown. Here, we show that lysophosphatidic acid (LPA) was formed during mild oxidation of LDL and was the active compound in mildly oxidized LDL and minimally modified LDL, initiating platelet activation and stimulating endothelial cell stress-fiber and gap formation. Antagonists of the LPA receptor prevented platelet and endothelial cell activation by mildly oxidized LDL. We also found that LPA accumulated in and was the primary platelet-activating lipid of atherosclerotic plaques. Notably, the amount of LPA within the human carotid atherosclerotic lesion was highest in the lipid-rich core, the region most thrombogenic and most prone to rupture. Given the potent biological activity of LPA on platelets and on cells of the vessel wall, our study identifies LPA as an atherothrombogenic molecule and suggests a possible strategy to prevent and treat atherosclerosis and cardiocerebrovascular diseases.

  20. Involvement of de Novo Protein Synthesis, Protein Kinase, Extracellular Ca2+, and Lipoxygenase in Arachidonic Acid Induction of 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Genes and Isoprenoid Accumulation in Potato (Solanum tuberosum L.).

    PubMed Central

    Choi, D.; Bostock, R. M.

    1994-01-01

    A series of inhibitors were tested to determine the participation of de novo protein synthesis, protein kinase activity, extracellular Ca2+, and lipoxygenase activity in arachidonic acid elicitation of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) gene expression and sesquiterpene phytoalexin biosynthesis in potato (Solanum tuberosum L. cv Kennebec). Gene-specific probes were used to discriminate effects on the expression of two HMGR genes (hmg1 and hmg2) that respond differentially in tuber tissue following wounding or elicitor treatment. Inhibition of protein synthesis with cycloheximide completely blocked arachidonate-induced hypersensitive necrosis and browning, including HMGR gene induction and phytoalexin accumulation. This suggests that proteins necessary for coupling arachidonic acid reception to HMGR mRNA accumulation are either rapidly turned over or not present constitutively and are induced following elicitor treatment. Staurosporin, a potent inhibitor of protein kinases, and ethyleneglycol-bis([beta]-aminoethyl ether)-N,N[prime]-tetraacetic acid, a Ca2+ chelator, inhibited arachidonate-induction of hmg2 gene expression and phytoalexin accumulation but did not inhibit the wound-induced expression of hmg1. However, staurosporin inhibited arachidonate's suppression of hmg1 gene expression. Eicosatetraynoic acid, a lipoxygenase inhibitor that suppresses elicitor-induced phytoalexin accumulation, also inhibited arachidonate's suppression of hmg1 and induction of hmg2. The results indicate that arachidonate's suppression of hmg1 and activation of hmg2 depend on a common intermediate or set of intermediates whose generation is sensitive to the inhibitors tested. PMID:12232162

  1. Long-chain 3-hydroxy fatty acids accumulating in long-chain 3-hydroxyacyl-CoA dehydrogenase and mitochondrial trifunctional protein deficiencies uncouple oxidative phosphorylation in heart mitochondria.

    PubMed

    Tonin, Anelise M; Amaral, Alexandre U; Busanello, Estela N B; Grings, Mateus; Castilho, Roger F; Wajner, Moacir

    2013-02-01

    Cardiomyopathy is a common clinical feature of some inherited disorders of mitochondrial fatty acid β-oxidation including mitochondrial trifunctional protein (MTP) and isolated long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiencies. Since individuals affected by these disorders present tissue accumulation of various fatty acids, including long-chain 3-hydroxy fatty acids, in the present study we investigated the effect of 3-hydroxydecanoic (3 HDCA), 3-hydroxydodecanoic (3 HDDA), 3-hydroxytetradecanoic (3 HTA) and 3-hydroxypalmitic (3 HPA) acids on mitochondrial oxidative metabolism, estimated by oximetry, NAD(P)H content, hydrogen peroxide production, membrane potential (ΔΨ) and swelling in rat heart mitochondrial preparations. We observed that 3 HTA and 3 HPA increased resting respiration and diminished the respiratory control and ADP/O ratios using glutamate/malate or succinate as substrates. Furthermore, 3 HDDA, 3 HTA and 3 HPA decreased ΔΨ, the matrix NAD(P)H pool and hydrogen peroxide production. These data indicate that these fatty acids behave as uncouplers of oxidative phosphorylation. We also verified that 3 HTA-induced uncoupling-effect was not mediated by the adenine nucleotide translocator and that this fatty acid induced the mitochondrial permeability transition pore opening in calcium-loaded organelles since cyclosporin A prevented the reduction of mitochondrial ΔΨ and swelling provoked by 3 HTA. The present data indicate that major 3-hydroxylated fatty acids accumulating in MTP and LCHAD deficiencies behave as strong uncouplers of oxidative phosphorylation potentially impairing heart energy homeostasis.

  2. Exogenous abscisic acid application decreases cadmium accumulation in Arabidopsis plants, which is associated with the inhibition of IRT1-mediated cadmium uptake.

    PubMed

    Fan, Shi Kai; Fang, Xian Zhi; Guan, Mei Yan; Ye, Yi Quan; Lin, Xian Yong; Du, Shao Ting; Jin, Chong Wei

    2014-01-01

    Cadmium (Cd) contamination of agricultural soils is an increasingly serious problem. Measures need to be developed to minimize Cd entering the human food chain from contaminated soils. We report here that, under Cd exposure condition, application with low doses of (0.1-0.5 μM) abscisic acid (ABA) clearly inhibited Cd uptake by roots and decreased Cd level in Arabidopsis wild-type plants (Col-0). Expression of IRT1 in roots was also strongly inhibited by ABA treatment. Decrease in Cd uptake and the inhibition of IRT1 expression were clearly lesser pronounced in an ABA-insensitive double mutant snrk2.2/2.3 than in the Col-0 in response to ABA application. The ABA-decreased Cd uptake was found to correlate with the ABA-inhibited IRT1 expression in the roots of Col-0 plants fed two different levels of iron. Furthermore, the Cd uptake of irt1 mutants was barely affected by ABA application. These results indicated that inhibition of IRT1 expression is involved in the decrease of Cd uptake in response to exogenous ABA application. Interestingly, ABA application increased the iron level in both Col-0 plants and irt1 mutants, suggesting that ABA-increased Fe acquisition does not depend on the IRT1 function, but on the contrary, the ABA-mediated inhibition of IRT1 expression may be due to the elevation of iron level in plants. From our results, we concluded that ABA application might increase iron acquisition, followed by the decrease in Cd uptake by inhibition of IRT1 activity. Thus, for crop production in Cd contaminated soils, developing techniques based on ABA application potentially is a promising approach for reducing Cd accumulation in edible organs in plants.

  3. The Arabidopsis Mitochondrial Protease FtSH4 Is Involved in Leaf Senescence via Regulation of WRKY-Dependent Salicylic Acid Accumulation and Signaling.

    PubMed

    Zhang, Shengchun; Li, Cui; Wang, Rui; Chen, Yaxue; Shu, Si; Huang, Ruihua; Zhang, Daowei; Li, Jian; Xiao, Shi; Yao, Nan; Yang, Chengwei

    2017-04-01

    Mitochondria and autophagy play important roles in the networks that regulate plant leaf senescence and cell death. However, the molecular mechanisms underlying the interactions between mitochondrial signaling and autophagy are currently not well understood. This study characterized the function of the Arabidopsis (Arabidopsis thaliana) mitochondrial AAA-protease gene FtSH4 in regulating autophagy and senescence, finding that FtSH4 mediates WRKY-dependent salicylic acid (SA) accumulation and signaling. Knockout of FtSH4 in the ftsh4-4 mutant resulted in severe leaf senescence, cell death, and high autophagy levels. The level of SA increased dramatically in the ftsh4-4 mutant. Expression of nahG in the ftsh4-4 mutant led to decreased SA levels and suppressed the leaf senescence and cell death phenotypes. The transcript levels of several SA synthesis and signaling genes, including SALICYLIC ACIDINDUCTION DEFICIENT2 (SID2), NON-RACE-SPECIFIC DISEASE RESISTANCE1 (NDR1), and NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1), increased significantly in the ftsh4-4 mutants compared with the wild type. Loss of function of SID2, NDR1, or NPR1 in the ftsh4-4 mutant reversed the ftsh4-4 senescence and autophagy phenotypes. Furthermore, ftsh4-4 mutants had elevated levels of transcripts of several WRKY genes, including WRKY40, WRKY46, WRKY51, WRKY60, WRKY63, and WRKY75; all of these WRKY proteins can bind to the promoter of SID2 Loss of function of WRKY75 in the ftsh4-4 mutants decreased the levels of SA and reversed the senescence phenotype. Taken together, these results suggest that the mitochondrial ATP-dependent protease FtSH4 may regulate the expression of WRKY genes by modifying the level of reactive oxygen species and the WRKY transcription factors that control SA synthesis and signaling in autophagy and senescence.

  4. Fenretinide mediated retinoic acid receptor signalling and inhibition of ceramide biosynthesis regulates adipogenesis, lipid accumulation, mitochondrial function and nutrient stress signalling in adipocytes and adipose tissue

    PubMed Central

    Mcilroy, George D.; Tammireddy, Seshu R.; Maskrey, Benjamin H.; Grant, Louise; Doherty, Mary K.; Watson, David G.; Delibegović, Mirela; Whitfield, Phillip D.; Mody, Nimesh

    2016-01-01

    Fenretinide (FEN) is a synthetic retinoid that inhibits obesity and insulin resistance in high-fat diet (HFD)-fed mice and completely prevents 3T3-L1 pre-adipocyte differentiation. The aim of this study was to determine the mechanism(s) of FEN action in 3T3-L1 adipocytes and in mice. We used the 3T3-L1 model of adipogenesis, fully differentiated 3T3-L1 adipocytes and adipose tissue from HFD-induced obese mice to investigate the mechanisms of FEN action. We measured expression of adipogenic and retinoid genes by qPCR and activation of nutrient-signalling pathways by western blotting. Global lipid and metabolite analysis was performed and specific ceramide lipid species measured by liquid chromatography-mass spectrometry. We provide direct evidence that FEN inhibits 3T3-L1 adipogenesis via RA-receptor (RAR)-dependent signaling. However, RARα antagonism did not prevent FEN-induced decreases in lipid levels in mature 3T3-L1 adipocytes, suggesting an RAR-independent mechanism. Lipidomics analysis revealed that FEN increased dihydroceramide lipid species 5- to 16-fold in adipocytes, indicating an inhibition of the final step of ceramide biosynthesis. A similar blockade in adipose tissue from FEN-treated obese mice was associated with a complete normalisation of impaired mitochondrial β-oxidation and tricarboxylic acid cycle flux. The FEN catabolite, 4-oxo-N-(4-hydroxyphenyl)retinamide (4-OXO), also decreased lipid accumulation without affecting adipogenesis. FEN and 4-OXO (but not RA) treatment additionally led to the activation of p38-MAPK, peIF2α and autophagy markers in adipocytes. Overall our data reveals FEN utilises both RAR-dependent and -independent pathways to regulate adipocyte biology, both of which may be required for FEN to prevent obesity and insulin resistance in vivo. PMID:26592777

  5. Mice deficient in mitochondrial glycerol-3-phosphate acyltransferase-1 have diminished myocardial triacylglycerol accumulation during lipogenic diet and altered phospholipid fatty acid composition

    PubMed Central

    Lewin, Tal M.; de Jong, Hendrik; Schwerbrock, Nicole J. M.; Hammond, Linda E.; Watkins, Steven M.; Combs, Terry P.; Coleman, Rosalind A.

    2008-01-01

    Glycerol-3-phosphate acyltransferase-1 (GPAT1), which is located on the outer mitochondrial membrane comprises up to 30% of total GPAT activity in the heart. It is one of at least four mammalian GPAT isoforms known to catalyze the initial, committed, and rate limiting step of glycerolipid synthesis. Because excess triacylglycerol (TAG) accumulates in cardiomyocytes in obesity and type 2 diabetes, we determined whether lack of GPAT1 would alter the synthesis of heart TAG and phospholipids after a 2-week high sucrose diet or a 3-month high fat diet. Even in the absence of hypertriglyceridemia, TAG increased 2-fold with both diets in hearts from wildtype mice. In contrast, hearts from Gpat1−/− mice contained 20–80% less TAG than the wildtype controls. In addition, hearts from Gpat1−/− mice fed the high-sucrose diet incorporate 60% less [14C]palmitate into heart TAG as compared to wildtype mice. Because GPAT1 prefers 16:0-CoA to other long chain acyl-CoA substrates, we determined the fatty acid composition of heart phospholipids. Compared to wildtype littermate controls, hearts from Gpat1−/− mice contained a lower amount of 16:0 in phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine/phosphatidylinositol and significantly more C20:4n6. Phosphatidylcholine and phosphatidylethanolamine from Gpat1−/− hearts also contained higher amounts of 18:0 and 18:1. Although at least three other GPAT isoforms are expressed in the heart, our data suggest that GPAT1 contributes significantly to cardiomyocyte TAG synthesis during lipogenic or high fat diets and influences the incorporation of 20:4n6 into heart phospholipids. PMID:18522808

  6. The Maize Viviparous8 Locus, Encoding a Putative ALTERED MERISTEM PROGRAM1-Like Peptidase, Regulates Abscisic Acid Accumulation and Coordinates Embryo and Endosperm Development1[W

    PubMed Central

    Suzuki, Masaharu; Latshaw, Susan; Sato, Yutaka; Settles, A. Mark; Koch, Karen E.; Hannah, L. Curtis; Kojima, Mikiko; Sakakibara, Hitoshi; McCarty, Donald R.

    2008-01-01

    We describe a mutant of Zea mays isolated from a W22 inbred transposon population, widow's peak mutant1 (wpk1), with an altered pattern of anthocyanin synthesis and aleurone cell differentiation in endosperm. In addition, a failure of the developing mutant embryo to form leaf initials is associated with decreased expression of a subset of meristem regulatory genes that includes Abphyl1 and Td1. We show that the viviparous8 (vp8) mutant has a similar pleiotropic phenotype in the W22 inbred background in contrast to the viviparous embryo phenotype exhibited in the standard genetic background, and we confirmed that wpk1 is allelic to vp8. Further genetic analysis revealed that the standard vp8 stock contains an unlinked, partially dominant suppressor of the vp8 mutation that is not present in W22. Consistent with the early-onset viviparous phenotype of vp8, expression of several embryonic regulators, including LEC1/B3 domain transcription factors, was reduced in the mutant embryo. Moreover, reduced abscisic acid (ABA) content of vp8/wpk1 embryos was correlated with altered regulation of ABA biosynthesis, as well as ABA catabolic pathways. The ABA biosynthetic gene Vp14 was down-regulated in the nonsuppressed background, whereas the ZmABA8′oxA1a ABA 8′-hydroxylase gene was strongly up-regulated in both genetic backgrounds. Molecular analysis revealed that Vp8 encodes a putative peptidase closely related to Arabidopsis thaliana ALTERED MERISTEM PROGRAM1. Because the Vp8 regulates meristem development as well as seed maturation processes, including ABA accumulation, we propose that VP8 is required for synthesis of an unidentified signal that integrates meristem and embryo formation in seeds. PMID:18203869

  7. The Maize Viviparous8 locus, encoding a putative ALTERED MERISTEM PROGRAM1-like peptidase, regulates abscisic acid accumulation and coordinates embryo and endosperm development.

    PubMed

    Suzuki, Masaharu; Latshaw, Susan; Sato, Yutaka; Settles, A Mark; Koch, Karen E; Hannah, L Curtis; Kojima, Mikiko; Sakakibara, Hitoshi; McCarty, Donald R

    2008-03-01

    We describe a mutant of Zea mays isolated from a W22 inbred transposon population, widow's peak mutant1 (wpk1), with an altered pattern of anthocyanin synthesis and aleurone cell differentiation in endosperm. In addition, a failure of the developing mutant embryo to form leaf initials is associated with decreased expression of a subset of meristem regulatory genes that includes Abphyl1 and Td1. We show that the viviparous8 (vp8) mutant has a similar pleiotropic phenotype in the W22 inbred background in contrast to the viviparous embryo phenotype exhibited in the standard genetic background, and we confirmed that wpk1 is allelic to vp8. Further genetic analysis revealed that the standard vp8 stock contains an unlinked, partially dominant suppressor of the vp8 mutation that is not present in W22. Consistent with the early-onset viviparous phenotype of vp8, expression of several embryonic regulators, including LEC1/B3 domain transcription factors, was reduced in the mutant embryo. Moreover, reduced abscisic acid (ABA) content of vp8/wpk1 embryos was correlated with altered regulation of ABA biosynthesis, as well as ABA catabolic pathways. The ABA biosynthetic gene Vp14 was down-regulated in the nonsuppressed background, whereas the ZmABA8'oxA1a ABA 8'-hydroxylase gene was strongly up-regulated in both genetic backgrounds. Molecular analysis revealed that Vp8 encodes a putative peptidase closely related to Arabidopsis thaliana ALTERED MERISTEM PROGRAM1. Because the Vp8 regulates meristem development as well as seed maturation processes, including ABA accumulation, we propose that VP8 is required for synthesis of an unidentified signal that integrates meristem and embryo formation in seeds.

  8. Lithocholic bile acid accumulated in yeast mitochondria orchestrates a development of an anti-aging cellular pattern by causing age-related changes in cellular proteome.

    PubMed

    Beach, Adam; Richard, Vincent R; Bourque, Simon; Boukh-Viner, Tatiana; Kyryakov, Pavlo; Gomez-Perez, Alejandra; Arlia-Ciommo, Anthony; Feldman, Rachel; Leonov, Anna; Piano, Amanda; Svistkova, Veronika; Titorenko, Vladimir I

    2015-01-01

    We have previously revealed that exogenously added lithocholic bile acid (LCA) extends the chronological lifespan of the yeast Saccharomyces cerevisiae, accumulates in mitochondria and alters mitochondrial membrane lipidome. Here, we use quantitative mass spectrometry to show that LCA alters the age-related dynamics of changes in levels of many mitochondrial proteins, as well as numerous proteins in cellular locations outside of mitochondria. These proteins belong to 2 regulons, each modulated by a different mitochondrial dysfunction; we call them a partial mitochondrial dysfunction regulon and an oxidative stress regulon. We found that proteins constituting these regulons (1) can be divided into several "clusters", each of which denotes a distinct type of partial mitochondrial dysfunction that elicits a different signaling pathway mediated by a discrete set of transcription factors; (2) exhibit 3 different patterns of the age-related dynamics of changes in their cellular levels; and (3) are encoded by genes whose expression is regulated by the transcription factors Rtg1p/Rtg2p/Rtg3p, Sfp1p, Aft1p, Yap1p, Msn2p/Msn4p, Skn7p and Hog1p, each of which is essential for longevity extension by LCA. Our findings suggest that LCA-driven changes in mitochondrial lipidome alter mitochondrial proteome and functionality, thereby enabling mitochondria to operate as signaling organelles that orchestrate an establishment of an anti-aging transcriptional program for many longevity-defining nuclear genes. Based on these findings, we propose a model for how such LCA-driven changes early and late in life of chronologically aging yeast cause a stepwise development of an anti-aging cellular pattern and its maintenance throughout lifespan.

  9. Tricarboxylic acid cycle intermediates accumulate at the onset of intense exercise in man but are not essential for the increase in muscle oxygen uptake.

    PubMed

    Bangsbo, Jens; Gibala, Martin J; Howarth, Krista R; Krustrup, Peter

    2006-09-01

    It was proposed that a contraction-induced increase in tricarboxylic acid cycle intermediates (TCAI) is obligatory for the increase in muscle oxygen uptake at the start of exercise. To test this hypothesis, we measured changes in muscle TCAI during the initial seconds of intense exercise and used dichloroacetate (DCA) in an attempt to alter the level of TCAI. Five men performed strenuous leg kicking exercise (64+/-8 W) under noninfused control (CON) and DCA-supplemented conditions; biopsies (vastus lateralis) were obtained at rest and after 5, 15, and 180 s of exercise. In CON, the total concentration of three measured TCAI (SigmaTCAI: citrate, malate, and fumarate) increased (p<0.05) by 71% during the first 15 s of exercise. The SigmaTCAI was lower (p<0.05) in DCA than in CON at rest [0.18+/-0.02 vs 0.64+/-0.09 mmol kg(-1) dry weight (d.w.)], after 5 s (0.30+/-0.07 vs 0.85+/-0.14 mmol kg(-1) d.w.), and 15 s of exercise (0.60+/-0.07 vs 1.09+/-0.16 mmol kg(-1) d.w.), but not different after 3 min (3.12+/-0.53 vs 3.23+/-0.55 mmol kg(-1) d.w.). Despite differences in the level of muscle TCAI, muscle phosphocreatine degradation was similar in DCA and CON during the first 15 s of exercise (17.5+/-3.3 vs 25.6+/-4.1 mmol kg(-1) d.w.). Taken together with our previous observation that DCA does not alter muscle oxygen uptake during the initial phase of intense leg kicking exercise (Bangsbo et al. Am J Physiol 282:R273-R280, 2002), the present data suggest that muscle TCAI accumulate during the initial seconds of exercise; however, this increase is not essential for the contraction-induced increase in mitochondrial respiration.

  10. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings : Analysis of Growth, Sugar Accumulation, and Gene Expression.

    PubMed

    Creelman, R A; Mason, H S; Bensen, R J; Boyer, J S; Mullet, J E

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite.

  11. Lithocholic bile acid accumulated in yeast mitochondria orchestrates a development of an anti-aging cellular pattern by causing age-related changes in cellular proteome

    PubMed Central

    Beach, Adam; Richard, Vincent R; Bourque, Simon; Boukh-Viner, Tatiana; Kyryakov, Pavlo; Gomez-Perez, Alejandra; Arlia-Ciommo, Anthony; Feldman, Rachel; Leonov, Anna; Piano, Amanda; Svistkova, Veronika; Titorenko, Vladimir I

    2015-01-01

    We have previously revealed that exogenously added lithocholic bile acid (LCA) extends the chronological lifespan of the yeast Saccharomyces cerevisiae, accumulates in mitochondria and alters mitochondrial membrane lipidome. Here, we use quantitative mass spectrometry to show that LCA alters the age-related dynamics of changes in levels of many mitochondrial proteins, as well as numerous proteins in cellular locations outside of mitochondria. These proteins belong to 2 regulons, each modulated by a different mitochondrial dysfunction; we call them a partial mitochondrial dysfunction regulon and an oxidative stress regulon. We found that proteins constituting these regulons (1) can be divided into several “clusters”, each of which denotes a distinct type of partial mitochondrial dysfunction that elicits a different signaling pathway mediated by a discrete set of transcription factors; (2) exhibit 3 different patterns of the age-related dynamics of changes in their cellular levels; and (3) are encoded by genes whose expression is regulated by the transcription factors Rtg1p/Rtg2p/Rtg3p, Sfp1p, Aft1p, Yap1p, Msn2p/Msn4p, Skn7p and Hog1p, each of which is essential for longevity extension by LCA. Our findings suggest that LCA-driven changes in mitochondrial lipidome alter mitochondrial proteome and functionality, thereby enabling mitochondria to operate as signaling organelles that orchestrate an establishment of an anti-aging transcriptional program for many longevity-defining nuclear genes. Based on these findings, we propose a model for how such LCA-driven changes early and late in life of chronologically aging yeast cause a stepwise development of an anti-aging cellular pattern and its maintenance throughout lifespan. PMID:25839782

  12. Hexanoic acid is a resistance inducer that protects tomato plants against Pseudomonas syringae by priming the jasmonic acid and salicylic acid pathways.

    PubMed

    Scalschi, Loredana; Vicedo, Begonya; Camañes, Gemma; Fernandez-Crespo, Emma; Lapeña, Leonor; González-Bosch, Carmen; García-Agustín, Pilar

    2013-05-01

    Hexanoic acid-induced resistance (Hx-IR) is effective against several pathogens in tomato plants. Our study of the mechanisms implicated in Hx-IR against Pseudomonas syringae pv. tomato DC3000 suggests that hexanoic acid (Hx) treatment counteracts the negative effect of coronatine (COR) and jasmonyl-isoleucine (JA-Ile) on the salicylic acid (SA) pathway. In Hx-treated plants, an increase in the expression of jasmonic acid carboxyl methyltransferase (JMT) and the SA marker genes PR1 and PR5 indicates a boost in this signalling pathway at the expense of a decrease in JA-Ile. Moreover, Hx treatment potentiates 12-oxo-phytodienoic acid accumulation, which suggests that this molecule might play a role per se in Hx-IR. These results support a positive relationship between the SA and JA pathways in Hx-primed plants. Furthermore, one of the mechanisms of virulence mediated by COR is stomatal re-opening on infection with P. syringae. In this work, we observed that Hx seems to inhibit stomatal opening in planta in the presence of COR, which suggests that, on infection in tomato, this treatment suppresses effector action to prevent bacterial entry into the mesophyll.

  13. A single amino acid in the helicase domain of PMMoV-S is responsible for its enhanced accumulation in C. chinense (L(3)L(3)) plants at 32°C.

    PubMed

    Tena, Fátima; Molina-Galdeano, Myriam; Serra, Maria Teresa; García-Luque, Isabel

    2012-05-25

    In Capsicum chinense (L(3)L(3)) plants a higher accumulation of the tobamovirus Pepper mild mottle virus strain S (PMMoV-S) as compared to the Italian strain PMMoV-I is detected when plants are grown at 32°C. By using a reverse genetic approach, we have established that a single amino acid at position 898 in the helicase domain of the polymerase protein, outside of the conserved regions of the helicase, is critical for the higher accumulation of PMMoV-S observed. It also is necessary for both increased accumulation of viral RNA of both polarities in pepper protoplasts and enhanced cell-to-cell movement in C. chinense plants. The influence of thermoresistance of PMMoV-S, a P(1,2) pathotype, and its prevalence on pepper cultivars over PMMoV-I, a P(1,2,3), pathotype, is discussed.

  14. Comparative study of two routes of administration of 5-aminolevulinic acid (oral and intratumoral via) and their effect on the accumulation of PpIX in tissues in murine model of breast cancer

    NASA Astrophysics Data System (ADS)

    González-Agüero, G.; Ramón-Gallegos, E.

    2012-10-01

    Protoporphyrin IX (PpIX) is a photosensitizer synthesized from 5-aminolevulinic acid (ALA) that has been used in photodynamic therapy (PDT) as a promising treatment for many types of cancer. In this work it was quantified the accumulation of PpIX in tumors and in different tissues of female mice (nu/nu) inoculated with breast cancer cells. Two routes of administration of ALA: gastric probe and intratumoral injection were used to find optimum time of accumulation and the via that induce the higher quantity of PpIX to improve the efficiency of PDT. The results show that the accumulation of PpIX using the intratumoral via is two times bigger than the oral via in tumors at 8 h of treatment. The concentrations obtained in the different tissues are not physiologically significant.

  15. Chemical Elicitor-Induced Modulation of Antioxidant Metabolism and Enhancement of Secondary Metabolite Accumulation in Cell Suspension Cultures of Scrophularia kakudensis Franch

    PubMed Central

    Manivannan, Abinaya; Soundararajan, Prabhakaran; Park, Yoo Gyeong; Jeong, Byoung Ryong

    2016-01-01

    Scrophularia kakudensis is an important medicinal plant with pharmaceutically valuable secondary metabolites. To develop a sustainable source of naturaceuticals with vital therapeutic importance, a cell suspension culture was established in S. kakudensis for the first time. Friable calli were induced from the leaf explants cultured on a Murashige and Skoog (MS) medium containing 3.0 mg·L−1 6-benzyladenine (BA) in a combination with 2 mg·L−1 2,4-dichlorophenoxy acetic acid (2,4-D). From the callus cultures, a cell suspension culture was initiated and the cellular differentiation was investigated. In addition, the effect of biotic elicitors such as methyl jasmonate (MeJa), salicylic acid (SA), and sodium nitroprusside (SNP) on the accumulation of secondary metabolites and antioxidant properties was demonstrated. Among the elicitors, the MeJa elicited the accumulation of total phenols, flavonoids, and acacetin, a flavonoid compound with multiple pharmaceutical values. Similarly, the higher concentrations of the MeJa significantly modulated the activities of antioxidant enzymes and enhanced the scavenging potentials of free radicals of cell suspension extracts. Overall, the outcomes of this study can be utilized for the large scale production of pharmaceutically important secondary metabolites from S. kakudensis through cell suspension cultures. PMID:26999126

  16. Growth and elemental accumulation of plants grown in acidic soil amended with coal fly ash-sewage sludge co-compost.

    PubMed

    Wong, Jonathan W C; Selvam, Ammaiyappan

    2009-10-01

    A greenhouse experiment was conducted to evaluate the growth and heavy-metal accumulation of Brassica chinensis and Agropyron elongatum in 10 and 25% ash-sludge co-compost (ASC)--amended loamy acidic soil (pH 4.51) at two different application rates: 20% and 40% (v/v). Soil pH increased, whereas electrical conductivity decreased with the amendment of ASC to soil. Bioavailable Cu, Zn, and Mn contents of ASC-amended soil decreased, whereas Ni, Pb, and B contents increased. Concentrations of bioavailable Cu, Zn, and Mn in sludge compost (SC)-amended soils were 5.57, 20.8, and 8.19 mg kg(-1), respectively. These concentrations were significantly lower than those in soil receiving an application rate of 20 or 25% ASC as 2.64, 8.48, and 5.26 mg kg(-1), respectively. Heavy metals and B contents of the composting mass significantly increased with an increase in ASC application rate from 20 to 40% (6.2 to 16.6 mg kg(-1) for 10% ASC- and 9.4 to 18.6 mg kg(-1) for 25% ASC-amended soil. However, when the ash content in co-compost increased from 10 to 25% during composting, bioavailable heavy-metal contents decreased. However, B contents increased with an increase in ash content. Addition of co-composts increased the dry-weight yield of the plants, and this increase was more obvious as the ash amendment rate in the co-composts and the ASC application rate increased. In case of B. chinensis, the biomass of 2.84 g/plant for 40% application of 25% ASC was significantly higher than SC (0.352 g/plant), which was 40% application of 10% ASC (0.434 g/plant) treatments. However, in A. elongatum, the differences between biomass of plants grown with 10% (1.34-1.94 g/ plant) and 25% ASC (2.12-2.21 g/plant) were not significantly different. Furthermore, there were fewer plant-available heavy metals in 25% ASC, which decreased the uptake of heavy metals by plants. ASC was favorable in increasing the growth of B. chinensis and A. elongatum. The optimal ash amendment to the sludge composting

  17. Growth and elemental accumulation of plants grown in acidic soil amended with coal fly ash-sewage sludge co-compost

    SciTech Connect

    Wong, J.W.C.; Selvam, A.

    2009-10-15

    A greenhouse experiment was conducted to evaluate the growth and heavy-metal accumulation of Brassica chinensis and Agropyron elongatum in 10 and 25% ash-sludge co-compost (ASC)-amended loamy acidic soil (pH 4.51) at two different application rates: 20% and 40% (v/v). Soil pH increased, whereas electrical conductivity decreased with the amendment of ASC to soil. Bioavailable Cu, Zn, and Mn contents of ASC-amended soil decreased, whereas Ni, Pb, and B contents increased. Concentrations of bioavailable Cu, Zn, and Mn in sludge compost (SC)-amended soils were 5.57, 20.8, and 8.19 mg kg{sup -1}, respectively. These concentrations were significantly lower than those in soil receiving an application rate of 20 or 25% ASC as 2.64, 8.48, and 5.26 mg kg(-1), respectively. Heavy metals and B contents of the composting mass significantly increased with an increase in ASC application rate from 20 to 40% (6.2 to 16.6 mg kg{sup -1} for 10% ASC- and 9.4 to 18.6 mg kg{sup -1} for 25% ASC-amended soil. However, when the ash content in co-compost increased from 10 to 25% during composting, bioavailable heavy-metal contents decreased. However, B contents increased with an increase in ash content. Addition of co-composts increased the dry-weight yield of the plants, and this increase was more obvious as the ash amendment rate in the co-composts and the ASC application rate increased. In case of B. chinensis, the biomass of 2.84 g/plant for 40% application of 25% ASC was significantly higher than SC (0.352 g/plant), which was 40% application of 10% ASC (0.434 g/plant) treatments. However, in A. elongatum, the differences between biomass of plants grown with 10% (1.34-1.94 g/ plant) and 25% ASC (2.12-2.21 g/plant) were not significantly different. ASC was favorable in increasing the growth of B. chinensis and A. elongatum. The optimal ash amendment to the sludge composting and ASC application rates were at 25 and 20%, respectively.

  18. Jasmonic acid is a downstream component in the modulation of somatic embryogenesis by Arabidopsis Class 2 phytoglobin

    PubMed Central

    Mira, Mohamed M.; Wally, Owen S. D.; Elhiti, Mohamed; El-Shanshory, Adel; Reddy, Dhadi S.; Hill, Robert D.; Stasolla, Claudio

    2016-01-01

    Previous studies have shown that the beneficial effect of suppression of the Arabidopsis phytoglobin 2 gene, PGB2, on somatic embryogenesis occurs through the accumulation of nitric oxide (NO) within the embryogenic cells originating from the cultured explant. NO activates the expression of Allene oxide synthase (AOS) and Lipoxygenase 2 (LOX2), genes encoding two key enzymes of the jasmonic acid (JA) biosynthetic pathway, elevating JA content within the embryogenic tissue. The number of embryos in the single aos1-1 mutant and pgb2-aos1-1 double mutant declined, and was not rescued by increasing levels of NO stimulating embryogenesis in wild-type tissue. NO also influenced JA responses by up-regulating PLANT DEFENSIN 1 (PDF1) and JASMONATE-ZIM-PROTEIN (JAZ1), as well as down-regulating MYC2. The NO and JA modulation of MYC2 and JAZ1 controlled embryogenesis. Ectopic expression of JAZ1 or suppression of MYC2 promoted the formation of somatic embryos, while repression of JAZ1 and up-regulation of MYC2 reduced the embryogenic performance. Sustained expression of JAZ1 induced the transcription of several indole acetic acid (IAA) biosynthetic genes, resulting in higher IAA levels in the embryogenic cells. Collectively these data fit a model integrating JA in the PGB2 regulation of Arabidopsis embryogenesis. Suppression of PGB2 increases JA through NO. Elevated levels of JA repress MYC2 and induce JAZ1, favoring the accumulation of IAA in the explants and the subsequent production of somatic embryos. PMID:26962208

  19. Sucrose phosphate synthase activity and the co-ordination of carbon partitioning during sucrose and amino acid accumulation in desiccation-tolerant leaf material of the C4 resurrection plant Sporobolus stapfianus during dehydration.

    PubMed

    Whittaker, Anne; Martinelli, Tommaso; Farrant, Jill M; Bochicchio, Adriana; Vazzana, Concetta

    2007-01-01

    Both sucrose and amino acids accumulate in desiccation-tolerant leaf material of the C(4) resurrection plant, Sporobolus stapfianus Gandoger (Poaceae). The present investigation was aimed at examining sucrose phosphate synthase (SPS) activity and various metabolic checkpoints involved in the co-ordination of carbon partitioning between these competing pathways during dehydration. In the initial phase of dehydration, photosynthesis and starch content declined to immeasurable levels, whilst significant increases in hexose sugars, sucrose, and amino acids were associated with concomitant significant increases in SPS and pyruvate kinase (PK) activities, and maximal activity levels of phosphoenolpyruvate carboxylase (PEPCase), NADP-dependent isocitrate dehydrogenase (NADP-ICDH), and NADH-dependent glutamate synthase (NADH-GOGAT). The next phase of dehydration was characterized by changes in metabolism coinciding with net hexose sugar phosphorylation. This phase was characterized by a further significant increase in sucrose accumulation, with increased rates of net sucrose accumulation and maximum rates of SPS activity measured under both saturating and limiting (inhibitory) conditions. SPS protein was also increased. The stronger competitive edge of SPS for carbon entering glycolysis during hexose phosphorylation was also demonstrated by the further decrease in respiration and the simultaneous, significant decline in both PEPCase and PK activities. A decreased anabolic demand for 2-oxoglutarate (2OG), which remained constant, was shown by the co-ordinated decrease in GOGAT. It is proposed that the further increase in amino acids in this phase of dehydration may be in part attributable to the breakdown of insoluble proteins.

  20. Allantoin, a stress-related purine metabolite, can activate jasmonate signaling in a MYC2-regulated and abscisic acid-dependent manner

    PubMed Central

    Takagi, Hiroshi; Ishiga, Yasuhiro; Watanabe, Shunsuke; Konishi, Tomokazu; Egusa, Mayumi; Akiyoshi, Nobuhiro; Matsuura, Takakazu; Mori, Izumi C.; Hirayama, Takashi; Kaminaka, Hironori; Shimada, Hiroshi; Sakamoto, Atsushi

    2016-01-01

    Allantoin is a metabolic intermediate of purine catabolism that often accumulates in stressed plants. Recently, we used Arabidopsis knockout mutants (aln) of ALLANTOINASE to show that this purine metabolite activates abscisic acid (ABA) production, thereby stimulating stress-related gene expression and enhancing seedling tolerance to abiotic stress. A detailed re-examination of the microarray data of an aln mutant (aln-1) confirmed the increased expression of ABA-related genes and also revealed altered expression of genes involved in jasmonic acid (JA) responses, probably under the control of MYC2, a master switch in the JA signaling pathway. Consistent with the transcriptome profiles, the aln-1 mutant displayed increased JA levels and enhanced responses to mechanical wounding and exogenous JA. Moreover, aln mutants demonstrated modestly increased susceptibility to Pseudomonas syringae and Pectobacterium carotovorum, probably reflecting the antagonistic action of MYC2 on the defense against these bacterial phytopathogens. Exogenously administered allantoin elicited the expression of JA-responsive genes, including MYC2, in wild-type plants, supporting the idea that allantoin might be responsible for the observed JA-related phenotypes of aln mutants. However, mutants deficient in bioactive JA (jar1-1), insensitive to JA (myc2-3), or deficient in ABA (aba2-1 and bglu18) suppressed the effect of exogenous allantoin. The suppression was further confirmed in aln-1 jar1-1 and aln-1 bglu18 double mutants. These results indicate that allantoin can activate the MYC2-regulated JA signaling pathway through ABA production. Overall, this study suggests a possible connection of purine catabolism with stress hormone homeostasis and signaling, and highlights the potential importance of allantoin in these interactions. PMID:26931169

  1. Jasmonic acid and salicylic acid activate a common defense system in rice

    PubMed Central

    Tamaoki, Daisuke; Seo, Shigemi; Yamada, Shoko; Kano, Akihito; Miyamoto, Ayumi; Shishido, Hodaka; Miyoshi, Seika; Taniguchi, Shiduku; Akimitsu, Kazuya; Gomi, Kenji

    2013-01-01

    Jasmonic acid (JA) and salicylic acid (SA) play important roles in plant defense systems. JA and SA signaling pathways interact antagonistically in dicotyledonous plants, but, the status of crosstalk between JA and SA signaling is unknown in monocots. Our rice microarray analysis showed that more than half of the genes upregulated by the SA analog BTH are also upregulated by JA, suggesting that a major portion of the SA-upregulated genes are regulated by JA-dependent signaling in rice. A common defense system that is activated by both JA and SA is thus proposed which plays an important role in pathogen defense responses in rice. PMID:23518581

  2. Neurotransmitter transporter family including SLC6A6 and SLC6A13 contributes to the 5-aminolevulinic acid (ALA)-induced accumulation of protoporphyrin IX and photodamage, through uptake of ALA by cancerous cells.

    PubMed

    Tran, Tai Tien; Mu, Anfeng; Adachi, Yuka; Adachi, Yasushi; Taketani, Shigeru

    2014-01-01

    δ-Aminolevulinic acid (ALA)-induced protoporphyrin accumulation is widely used in the treatment of cancer, as photodynamic therapy (PDT). To clarify the mechanisms of ALA uptake by tumor cells, we have examined the ALA-induced accumulation of protoporphyrin by the treatment of colon cancer DLD-1 and epithelial cancer HeLa cells with γ-aminobutyric acid (GABA)-related compounds. When the cells were treated with GABA, taurine and β-alanine, the level of protoporphyrin was decreased, suggesting that plasma membrane transporters involved in the transport of neurotransmitters contribute to the uptake of ALA. By transfection with neurotransmitter transporters SLC6A6, SLC6A8 and SLC6A13 cDNA, the ALA- and ALA methylester-dependent accumulation of protoporphyrin markedly increased in HEK293T cells, dependent on an increase in the uptake of ALA. When ALA-treated cells were exposed to white light, the extent of photodamage increased in SLC6A6- and SLC6A13-expressing cells. Conversely, knockdown of SLC6A6 or SLC6A13 with siRNAs in DLD-1 and HeLa cells decreased the ALA-induced accumulation. The expression of SLC6A6 and SLC6A13 was found in some cancer cell lines. Immunohistochemical studies revealed that the presence of these transporters was elevated in colon cancerous cells. These results indicated that neurotransmitter transporters including SLC6A6 and SLC6A13 mediate the uptake of ALA and can play roles in the enhancement of ALA-induced accumulation of protoporphyrin in cancerous cells.

  3. Genetic enhancement of palmitic acid accumulation in cotton seed oil through RNAi down-regulation of ghKAS2 encoding β-ketoacyl-ACP synthase II (KASII).

    PubMed

    Liu, Qing; Wu, Man; Zhang, Baolong; Shrestha, Pushkar; Petrie, James; Green, Allan G; Singh, Surinder P

    2017-01-01

    Palmitic acid (C16:0) already makes up approximately 25% of the total fatty acids in the conventional cotton seed oil. However, further enhancements in palmitic acid content at the expense of the predominant unsaturated fatty acids would provide increased oxidative stability of cotton seed oil and also impart the high melting point required for making margarine, shortening and confectionary products free of trans fatty acids. Seed-specific RNAi-mediated down-regulation of β-ketoacyl-ACP synthase II (KASII) catalysing the elongation of palmitoyl-ACP to stearoyl-ACP has succeeded in dramatically increasing the C16 fatty acid content of cotton seed oil to well beyond its natural limits, reaching up to 65% of total fatty acids. The elevated C16 levels were comprised of predominantly palmitic acid (C16:0, 51%) and to a lesser extent palmitoleic acid (C16:1, 11%) and hexadecadienoic acid (C16:2, 3%), and were stably inherited. Despite of the dramatic alteration of fatty acid composition and a slight yet significant reduction in oil content in these high-palmitic (HP) lines, seed germination remained unaffected. Regiochemical analysis of triacylglycerols (TAG) showed that the increased levels of palmitic acid mainly occurred at the outer positions, while C16:1 and C16:2 were predominantly found in the sn-2 position in both TAG and phosphatidylcholine. Crossing the HP line with previously created high-oleic (HO) and high-stearic (HS) genotypes demonstrated that HP and HO traits could be achieved simultaneously; however, elevation of stearic acid was hindered in the presence of high level of palmitic acid.

  4. Expression of a borage desaturase cDNA containing an N-terminal cytochrome b5 domain results in the accumulation of high levels of delta6-desaturated fatty acids in transgenic tobacco.

    PubMed

    Sayanova, O; Smith, M A; Lapinskas, P; Stobart, A K; Dobson, G; Christie, W W; Shewry, P R; Napier, J A

    1997-04-15

    gamma-Linolenic acid (GLA; C18:3 delta(6,9,12)) is a component of the seed oils of evening primrose (Oenothera spp.), borage (Borago officinalis L.), and some other plants. It is widely used as a dietary supplement and for treatment of various medical conditions. GLA is synthesized by a delta6-fatty acid desaturase using linoleic acid (C18:2 delta(9,12)) as a substrate. To enable the production of GLA in conventional oilseeds, we have isolated a cDNA encoding the delta6-fatty acid desaturase from developing seeds of borage and confirmed its function by expression in transgenic tobacco plants. Analysis of leaf lipids from a transformed plant demonstrated the accumulation of GLA and octadecatetraenoic acid (C18:4 delta(6,9,12,15)) to levels of 13.2% and 9.6% of the total fatty acids, respectively. The borage delta6-fatty acid desaturase differs from other desaturase enzymes, characterized from higher plants previously, by the presence of an N-terminal domain related to cytochrome b5.

  5. Co-expression of the borage Delta 6 desaturase and the Arabidopsis Delta 15 desaturase results in high accumulation of stearidonic acid in the seeds of transgenic soybean.

    PubMed

    Eckert, Helene; La Vallee, Brad; Schweiger, Bruce J; Kinney, Anthony J; Cahoon, Edgar B; Clemente, Tom

    2006-10-01

    Two relatively rare fatty acids, gamma-linolenic acid (GLA) and stearidonic acid (STA), have attracted much interest due to their nutraceutical and pharmaceutical potential. STA, in particular, has been considered a valuable alternative source for omega-3 fatty acids due to its enhanced conversion efficiency in animals to eicosapentaenoic acid when compared with the more widely consumed omega-3 fatty acid, alpha-linolenic acid (ALA), present in most vegetable oils. Exploiting the wealth of information currently available on in planta oil biosynthesis and coupling this information with the tool of genetic engineering it is now feasible to deliberately perturb fatty acid pools to generate unique oils in commodity crops. In an attempt to maximize the STA content of soybean oil, a borage Delta(6) desaturase and an Arabidopsis Delta(15) desaturase were pyramided by either sexual crossing of transgenic events, re-transformation of a Delta(6) desaturase event with the Delta(15) desaturase or co-transformation of both desaturases. Expression of both desaturases in this study was under the control of the seed-specific soybean beta-conglycinin promoter. Soybean events that carried only the Delta(15 )desaturase possessed a significant elevation of ALA content, while events with both desaturases displayed a relative STA abundance greater than 29%, creating a soybean with omega-3 fatty acids representing over 60% of the fatty acid profile. Analyses of the membrane lipids in a subset of the transgenic events suggest that soybean seeds compensate for enhanced production of polyunsaturated fatty acids by increasing the relative content of palmitic acid in phosphatidylcholine and other phospholipids.

  6. Dietary gamma-linolenic acid in the form of borage oil causes less body fat accumulation accompanying an increase in uncoupling protein 1 mRNA level in brown adipose tissue.

    PubMed

    Takahashi, Y; Ide, T; Fujita, H

    2000-10-01

    Rats were fed a low-fat diet containing 2% safflower oil or 20% fat diets containing either safflower oil rich in linoleic acid, borage oil containing 25% gamma (gamma)-linolenic acid or enzymatically prepared gamma-linolenic acid enriched borage oil containing 47% gamma-linolenic acid for 14 days. Energy intake and growth of animals were the same among groups. A high safflower oil diet compared with a low-fat diet caused significant increases in both epididymal and perirenal white adipose tissue weights. However, high-fat diets rich in gamma-linolenic acid failed to do so. Compared with a low-fat diet, all the high-fat diets increased mRNA levels of uncoupling protein 1 and lipoprotein lipase in brown adipose tissue. The extents of the increase were greater with high-fat diets rich in gamma-linolenic acid. Various high-fat diets, compared with a low-fat diet, decreased glucose transporter 4 mRNA in white adipose tissue to the same levels. The amount and types of dietary fat did not affect the leptin mRNA level in epididymal white adipose tissue. However, a high safflower oil diet, but not high-fat diets rich in gamma-linolenic acid relative to a low-fat diet, increased perirenal white adipose tissue leptin mRNA levels. All high-fat diets, relative to a low-fat diet, increased the hepatic mitochondrial fatty acid oxidation rate and fatty acid oxidation enzyme mRNA abundances to the same levels. High-fat diets also increased these parameters in the peroxisomal pathway, and the increases were greater with high-fat diets rich in gamma-linolenic acid. The physiological activity in increasing brown adipose tissue gene expression and peroxisomal fatty acid oxidation was similar between the two types of borage oil differing in gamma-linolenic acid content. It was suggested that dietary gamma-linolenic acid attenuates body fat accumulation through the increase in gene expressions of uncoupling protein 1 in brown adipose tissue. An increase in hepatic peroxisomal fatty acid

  7. Curcumin and Ellagic acid synergistically induce ROS generation, DNA damage, p53 accumulation and apoptosis in HeLa cervical carcinoma cells.

    PubMed

    Kumar, Devbrat; Basu, Soumya; Parija, Lucy; Rout, Deeptimayee; Manna, Sanjeet; Dandapat, Jagneshwar; Debata, Priya Ranjan

    2016-07-01

    Cervical cancer and precancerous lesions of the cervix continue to be a global health issue, and the medication for the treatment for chronic HPV infection so far has not been effective. Potential anticancer and anti HPV activities of two known phytochemicals, Curcumin and Ellagic acid were evaluated in HeLa cervical cancer cells. Curcumin is a natural compound found in the root of Curcuma longa plant and Ellagic acid a polyphenol found in fruits of strawberries, raspberries and walnuts. The combination of Curcumin and Ellagic acid at various concentrations showed better anticancer properties than either of the drug when used alone as evidenced by MTT assay. Besides this, Curcumin and Ellagic acid also restore p53, induce ROS formation and DNA damage. Mechanistic study further indicated that Curcumin and Ellagic acid show anti-HPV activity as evidenced by decrease in the HPV E6 oncoprotein on HeLa cells.

  8. Excessive reactive oxygen species induces apoptosis in fibroblasts: Role of mitochondrially accumulated hyaluronic acid binding protein 1 (HABP1/p32/gC1qR)

    SciTech Connect

    Chowdhury, Anindya Roy; Ghosh, Ilora Datta, Kasturi

    2008-02-01

    Constitutively expressed HABP1 in normal murine fibroblast cell line induces growth perturbation, morphological abnormalities alongwith initiation of apoptosis. Here, we demonstrate that though HABP1 accumulation started in mitochondria from 48 hr of growth, induction of apoptosis with the release of cytochrome c and apoptosome complex formation occurred only after 60 hr. This mitochondrial dysfunction was due to gradual increase in ROS generation in HABP1 overexpressing cells. Along with ROS generation, increased Ca{sup