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Sample records for abscisic acid salicylic

  1. Lipoxygenase in Caragana jubata responds to low temperature, abscisic acid, methyl jasmonate and salicylic acid.

    PubMed

    Bhardwaj, Pardeep Kumar; Kaur, Jagdeep; Sobti, Ranbir Chander; Ahuja, Paramvir Singh; Kumar, Sanjay

    2011-09-01

    Lipoxygenase (LOX) catalyses oxygenation of free polyunsaturated fatty acids into oxylipins, and is a critical enzyme of the jasmonate signaling pathway. LOX has been shown to be associated with biotic and abiotic stress responses in diverse plant species, though limited data is available with respect to low temperature and the associated cues. Using rapid amplification of cDNA ends, a full-length cDNA (CjLOX) encoding lipoxygenase was cloned from apical buds of Caragana jubata, a temperate plant species that grows under extreme cold. The cDNA obtained was 2952bp long consisting of an open reading frame of 2610bp encoding 869 amino acids protein. Multiple alignment of the deduced amino acid sequence with those of other plants demonstrated putative LH2/ PLAT domain, lipoxygenase iron binding catalytic domain and lipoxygenase_2 signature sequences. CjLOX exhibited up- and down-regulation of gene expression pattern in response to low temperature (LT), abscisic acid (ABA), methyl jasmonate (MJ) and salicylic acid (SA). Among all the treatments, a strong up-regulation was observed in response to MJ. Data suggests an important role of jasmonate signaling pathway in response to LT in C. jubata.

  2. Salicylic acid antagonizes abscisic acid inhibition of shoot growth and cell cycle progression in rice

    NASA Astrophysics Data System (ADS)

    Meguro, Ayano; Sato, Yutaka

    2014-04-01

    We analysed effects of abscisic acid (ABA, a negative regulatory hormone), alone and in combination with positive or neutral hormones, including salicylic acid (SA), on rice growth and expression of cell cycle-related genes. ABA significantly inhibited shoot growth and induced expression of OsKRP4, OsKRP5, and OsKRP6. A yeast two-hybrid assay showed that OsKRP4, OsKRP5, and OsKRP6 interacted with OsCDKA;1 and/or OsCDKA;2. When SA was simultaneously supplied with ABA, the antagonistic effect of SA completely blocked ABA inhibition. SA also blocked ABA inhibition of DNA replication and thymidine incorporation in the shoot apical meristem. These results suggest that ABA arrests cell cycle progression by inducing expression of OsKRP4, OsKRP5, and OsKRP6, which inhibit the G1/S transition, and that SA antagonizes ABA by blocking expression of OsKRP genes.

  3. Abscisic acid interacts antagonistically with salicylic acid signaling pathway in rice-Magnaporthe grisea interaction.

    PubMed

    Jiang, Chang-Jie; Shimono, Masaki; Sugano, Shoji; Kojima, Mikiko; Yazawa, Katsumi; Yoshida, Riichiro; Inoue, Haruhiko; Hayashi, Nagao; Sakakibara, Hitoshi; Takatsuji, Hiroshi

    2010-06-01

    Plant hormones play pivotal signaling roles in plant-pathogen interactions. Here, we report characterization of an antagonistic interaction of abscisic acid (ABA) with salicylic acid (SA) signaling pathways in the rice-Magnaporthe grisea interaction. Exogenous application of ABA drastically compromised the rice resistance to both compatible and incompatible M. grisea strains, indicating that ABA negatively regulates both basal and resistance gene-mediated blast resistance. ABA markedly suppressed the transcriptional upregulation of WRKY45 and OsNPR1, the two key components of the SA signaling pathway in rice, induced by SA or benzothiadiazole or by blast infection. Overexpression of OsNPR1 or WRKY45 largely negated the enhancement of blast susceptibility by ABA, suggesting that ABA acts upstream of WRKY45 and OsNPR1 in the rice SA pathway. ABA-responsive genes were induced during blast infection in a pattern reciprocal to those of WRKY45 and OsPR1b in the compatible rice-blast interaction but only marginally in the incompatible one. These results suggest that the balance of SA and ABA signaling is an important determinant for the outcome of the rice-M. grisea interaction. ABA was detected in hyphae and conidia of M. grisea as well as in culture media, implying that blast-fungus-derived ABA could play a role in triggering ABA signaling at host infection sites.

  4. Alleviation of Osmotic Stress Effects by Exogenous Application of Salicylic or Abscisic Acid on Wheat Seedlings

    PubMed Central

    Marcińska, Izabela; Czyczyło-Mysza, Ilona; Skrzypek, Edyta; Grzesiak, Maciej T.; Janowiak, Franciszek; Filek, Maria; Dziurka, Michał; Dziurka, Kinga; Waligórski, Piotr; Juzoń, Katarzyna; Cyganek, Katarzyna; Grzesiak, Stanisław

    2013-01-01

    The aim of the study was to assess the role of salicylic acid (SA) and abscisic acid (ABA) in osmotic stress tolerance of wheat seedlings. This was accomplished by determining the impact of the acids applied exogenously on seedlings grown under osmotic stress in hydroponics. The investigation was unique in its comprehensiveness, examining changes under osmotic stress and other conditions, and testing a number of parameters simultaneously. In both drought susceptible (SQ1) and drought resistant (CS) wheat cultivars, significant physiological and biochemical changes were observed upon the addition of SA (0.05 mM) or ABA (0.1 μM) to solutions containing half-strength Hoagland medium and PEG 6000 (−0.75 MPa). The most noticeable result of supplementing SA or ABA to the medium (PEG + SA and PEG + ABA) was a decrease in the length of leaves and roots in both cultivars. While PEG treatment reduced gas exchange parameters, chlorophyll content in CS, and osmotic potential, and conversely, increased lipid peroxidation, soluble carbohydrates in SQ1, proline content in both cultivars and total antioxidants activity in SQ1, PEG + SA or PEG + ABA did not change the values of these parameters. Furthermore, PEG caused a two-fold increase of endogenous ABA content in SQ1 and a four-fold increase in CS. PEG + ABA increased endogenous ABA only in SQ1, whereas PEG + SA caused a greater increase of ABA content in both cultivars compared to PEG. In PEG-treated plants growing until the harvest, a greater decrease of yield components was observed in SQ1 than in CS. PEG + SA, and particularly PEG + ABA, caused a greater increase of these yield parameters in CS compared to SQ1. In conclusion, SA and ABA ameliorate, particularly in the tolerant wheat cultivar, the harmful effects and after effects of osmotic stress induced by PEG in hydroponics through better osmotic adjustment achieved by an increase in proline and carbohydrate content as well as by an increase in antioxidant activity

  5. Antagonism between salicylic and abscisic acid reflects early host-pathogen conflict and moulds plant defence responses.

    PubMed

    de Torres Zabala, Marta; Bennett, Mark H; Truman, William H; Grant, Murray R

    2009-08-01

    The importance of phytohormone balance is increasingly recognized as central to the outcome of plant-pathogen interactions. Recently it has been demonstrated that abscisic acid signalling pathways are utilized by the bacterial phytopathogen Pseudomonas syringae to promote pathogenesis. In this study, we examined the dynamics, inter-relationship and impact of three key acidic phytohormones, salicylic acid, abscisic acid and jasmonic acid, and the bacterial virulence factor, coronatine, during progression of P. syringae infection of Arabidopsis thaliana. We show that levels of SA and ABA, but not JA, appear to play important early roles in determining the outcome of the infection process. SA is required in order to mount a full innate immune responses, while bacterial effectors act rapidly to activate ABA biosynthesis. ABA suppresses inducible innate immune responses by down-regulating SA biosynthesis and SA-mediated defences. Mutant analyses indicated that endogenous ABA levels represent an important reservoir that is necessary for effector suppression of plant-inducible innate defence responses and SA synthesis prior to subsequent pathogen-induced increases in ABA. Enhanced susceptibility due to loss of SA-mediated basal resistance is epistatically dominant over acquired resistance due to ABA deficiency, although ABA also contributes to symptom development. We conclude that pathogen-modulated ABA signalling rapidly antagonizes SA-mediated defences. We predict that hormonal perturbations, either induced or as a result of environmental stress, have a marked impact on pathological outcomes, and we provide a mechanistic basis for understanding priming events in plant defence.

  6. Hardening with salicylic acid induces concentration-dependent changes in abscisic acid biosynthesis of tomato under salt stress.

    PubMed

    Horváth, Edit; Csiszár, Jolán; Gallé, Ágnes; Poór, Péter; Szepesi, Ágnes; Tari, Irma

    2015-07-01

    The role of salicylic acid (SA) in the control of abscisic acid (ABA) biosynthesis is controversial although both plant growth regulators may accumulate in tissues under abiotic and biotic stress conditions. Hardening of tomato plants to salinity stress with 10(-4)M SA ("high SA") resulted in an up-regulation of ABA biosynthesis genes, zeaxanthin epoxidase (SlZEP1), 9-cis-epoxycarotenoid dioxygenase (SlNCED1) and aldehyde oxidases (SlAO1 and SlAO2) in the roots and led to ABA accumulation both in root and leaf tissues. In plants pre-treated with lower concentration of SA (10(-7)M, "low SA"), the up-regulation of SlNCED1 in the roots promoted ABA accumulation in the root tissues but the hormone concentration remained at control level in the leaves. Salt stress induced by 100mM NaCl reduced the transcript abundance of ABA biosynthetic genes and inhibited SlAO activity in plants hardened with "high SA", but the tissues maintained root ABA level over the untreated control. The combined effect of "high SA" and ABA under salt stress led to partially recovered photosynthetic activity, reduced ethylene production in root apices, and restored root growth, which is one of the main features of salt tolerance. Unlike "high SA", hardening with "low SA" had no influence on ethylene production, and led to reduced elongation of roots in plants exposed to 100mM NaCl. The up-regulation of carotenoid cleavage dioxygenases SlCCD1A and SlCCD1B by SA, which produce apocarotenoids, may open new pathways in SA sensing and signalling processes.

  7. Thermotolerance and antioxidant systems in Agrostis stolonifera: involvement of salicylic acid, abscisic acid, calcium, hydrogen peroxide, and ethylene.

    PubMed

    Larkindale, Jane; Huang, Bingru

    2004-04-01

    This study investigated whether pre-treating plants with specific putative signaling components and heat acclimation would induce tolerance of a cool-season grass, creeping bentgrass (Agrostis stolonifera var. palustris), to subsequent heat stress and whether thermotolerance induction of those pretreatments was associated with the regulation of antioxidant regenerating enzymes. The treatments included foliar application of salicylic acid (SA), abscisic acid (ABA), calcium chloride (CaCl2), hydrogen peroxide (H2O2), 1-aminocyclopropane-1-carboxylic acid (ACC, a precursor of ethylene prior to the exposure of plants to heat stress (35 degrees C) in a growth chamber. Physiological measurements including turf quality, leaf photosynthetic rate, and levels of oxidative damage demonstrated that all treatments increased heat tolerance. The better heat tolerance for pre-treated plants as compared to controls was related to the protection of oxidative damage under heat stress. APX activity increased over the first 2 days and 5 days of heating for ACC and CaCl2 respectively, but for only 12 h for H2O2. SA and ABA pre-treatments had no effects on APX activity earlier, but maintained APX activity at a significantly higher level than in controls after 24 h of heating. SA and ABA pre-treatments had no effects on POX activity. ACC treatment significantly increased POX activity. Pre-treatment with CaCl2, H2O2, and HA reduced POX activity, particularly during the later phase of heating. Plants treated with SA, CaCl2, H2O2 and HA had lower CAT activity than their control plants prior to heating and within 48 h of heat stress. ABA and ACC pre-treatments maintained higher CAT activity than the controls after 48 h of heating. ACC, CaCl2, or HA pre-treatments increased SOD activity only before 5 days of heat stress. SA and ABA pre-treatments had less effect on APX activity earlier under heat stress. These results suggest that specific groups of potential signaling molecules may induce

  8. Metabolic pathways regulated by abscisic acid, salicylic acid and γ-aminobutyric acid in association with improved drought tolerance in creeping bentgrass (Agrostis stolonifera).

    PubMed

    Li, Zhou; Yu, Jingjin; Peng, Yan; Huang, Bingru

    2017-01-01

    Abscisic acid (ABA), salicylic acid (SA) and γ-aminobutyric acid (GABA) are known to play roles in regulating plant stress responses. This study was conducted to determine metabolites and associated pathways regulated by ABA, SA and GABA that could contribute to drought tolerance in creeping bentgrass (Agrostis stolonifera). Plants were foliar sprayed with ABA (5 μM), GABA (0.5 mM) and SA (10 μM) or water (untreated control) prior to 25 days drought stress in controlled growth chambers. Application of ABA, GABA or SA had similar positive effects on alleviating drought damages, as manifested by the maintenance of lower electrolyte leakage and greater relative water content in leaves of treated plants relative to the untreated control. Metabolic profiling showed that ABA, GABA and SA induced differential metabolic changes under drought stress. ABA mainly promoted the accumulation of organic acids associated with tricarboxylic acid cycle (aconitic acid, succinic acid, lactic acid and malic acid). SA strongly stimulated the accumulation of amino acids (proline, serine, threonine and alanine) and carbohydrates (glucose, mannose, fructose and cellobiose). GABA enhanced the accumulation of amino acids (GABA, glycine, valine, proline, 5-oxoproline, serine, threonine, aspartic acid and glutamic acid) and organic acids (malic acid, lactic acid, gluconic acid, malonic acid and ribonic acid). The enhanced drought tolerance could be mainly due to the enhanced respiration metabolism by ABA, amino acids and carbohydrates involved in osmotic adjustment (OA) and energy metabolism by SA, and amino acid metabolism related to OA and stress-defense secondary metabolism by GABA.

  9. Development of an ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry method for the simultaneous determination of salicylic acid, jasmonic acid, and abscisic acid in rose leaves.

    PubMed

    Bosco, Renato; Daeseleire, Els; Van Pamel, Els; Scariot, Valentina; Leus, Leen

    2014-07-09

    This paper describes a method to detect and quantitate the endogenous plant hormones (±)-2-cis-4-trans-abscisic acid, (-)-jasmonic acid, and salicylic acid by means of ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in hybrid rose leaf matrices. Deuterium-labeled [(2)H6] (+)-2-cis-4-trans-abscisic acid, [(2)H6] (±)-jasmonic acid, and [(2)H4]-salicylic acid were used as internal standards. Rose samples (10 mg) were extracted with methanol/water/acetic acid (10:89:1) and subsequently purified on an Oasis MCX 1 cm(3) Vac SPE cartridge. Performance characteristics were validated according to Commission Decision 2002/657/EC. Recovery, repeatability, and within-laboratory reproducibility were acceptable for all phytohormones tested at three different concentrations. The decision limit and detection capability for (±)-2-cis-4-trans-abscisic acid, (-)-jasmonic acid, and salicylic acid were 0.0075 and 0.015 μg/g, 0.00015 and 0.00030 μg/g, and 0.0089 and 0.018 μg/g, respectively. Matrix effects (signal suppression or enhancement) appeared to be high for all substances considered, implying the need for quantitation based on matrix-matched calibration curves.

  10. Salicylic acids

    PubMed Central

    Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

    2012-01-01

    Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. PMID:22301975

  11. Novel interrelationship between salicylic acid, abscisic acid, and PIP2-specific phospholipase C in heat acclimation-induced thermotolerance in pea leaves.

    PubMed

    Liu, Hong-Tao; Liu, Yan-Yan; Pan, Qiu-Hong; Yang, Hao-Ru; Zhan, Ji-Cheng; Huang, Wei-Dong

    2006-01-01

    Increasing evidence suggests that heat acclimation and exogenous salicylic acid (SA) and abscisic acid (ABA) may lead to the enhancement of thermotolerance in plants. In this study, the roles that free SA, conjugated SA, ABA, and phosphatidylinositol-4,5-bisphosphate (PIP(2))-specific phospholipase C (PLC) play in thermotolerance development induced by heat acclimation (38 degrees C) were investigated. To evaluate their potential functions, three inhibitors of synthesis or activity were infiltrated into pea leaves prior to heat acclimation treatment. The results showed that the burst of free SA in response to heat acclimation could be attributed to the conversion of SA 2-O-D-glucose, the main conjugated form of SA, to free SA. Inhibition of ABA biosynthesis also resulted in a defect in the free SA peak during heat acclimation. In acquired thermotolerance assessment, the greatest weakness of antioxidant enzyme activity and the most severe heat injury (malondialdehyde content and degree of wilting) were found in pea leaves pre-treated with neomycin, a well-known inhibitor of PIP(2)-PLC activity. PsPLC gene expression was activated by exogenous ABA, SA treatments, and heat acclimation after pre-treatments with a SA biosynthesis inhibitor. From these results, PIP(2)-PLC appears to play a key role in free SA- and ABA-associated reinforcement of thermotolerance resulting from heat acclimation.

  12. 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

  13. 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.

  14. Jasmonic Acid, Abscisic Acid, and Salicylic Acid Are Involved in the Phytoalexin Responses of Rice to Fusarium fujikuroi, a High Gibberellin Producer Pathogen.

    PubMed

    Siciliano, Ilenia; Amaral Carneiro, Greice; Spadaro, Davide; Garibaldi, Angelo; Gullino, Maria Lodovica

    2015-09-23

    Fusarium fujikuroi, the causal agent of bakanae disease, is the main seedborne pathogen on rice. To understand the basis of rice resistance, a quantitative method to simultaneously detect phytohormones and phytoalexins was developed by using HPLC-MS/MS. With this method dynamic profiles and possible interactions of defense-related phytohormones and phytoalexins were investigated on two rice cultivars, inoculated or not with F. fujikuroi. In the resistant cultivar Selenio, the presence of pathogen induced high production of phytoalexins, mainly sakuranetin, and symptoms of bakanae were not observed. On the contrary, in the susceptible genotype Dorella, the pathogen induced the production of gibberellin and abscisic acid and inhibited jasmonic acid production, phytoalexins were very low, and bakanae symptoms were observed. The results suggested that a wide range of secondary metabolites are involved in plant defense against pathogens and phytoalexin synthesis could be an important factor for rice resistance against bakanae disease.

  15. Salicylic Acid Topical

    MedlinePlus

    Propa pH® Peel-Off Acne Mask ... pimples and skin blemishes in people who have acne. Topical salicylic acid is also used to treat ... medications called keratolytic agents. Topical salicylic acid treats acne by reducing swelling and redness and unplugging blocked ...

  16. Abscission: Role of Abscisic Acid

    PubMed Central

    Cracker, L. E.; Abeles, F. B.

    1969-01-01

    The effect of abscisic acid on cotton (Gossypium hirsutum L. cv. Acala 4-42) and bean (Phaseolus vulgaris L. cv. Red Kidney) explants was 2-fold. It increased ethylene production from the explants, which was found to account for some of its ability to accelerate abscission. Absci is acid also increased the activity of cellulase. Increased synthesis of cellulase was not du to an increase in aging of the explants but rather was an effect of abscisic acid on the processes that lead to cellulase synthesis or activity. PMID:16657181

  17. Phosphorus derivatives of salicylic acid

    NASA Astrophysics Data System (ADS)

    Chvertkina, L. V.; Khoklov, P. S.; Mironov, Vladimir F.

    1992-10-01

    The present state of work on the methods of synthesis, chemical properties, and practical applications of phosphorus-containing derivatives of salicylic acid has been reviewed. The characteristics of the chemical transformations of cyclic and acyclic phosphorus derivatives of salicylic acid related to the coordination state of the phosphorus atom have been examined. The bibliography includes 158 references.

  18. Abscisic Acid Synthesis and Response

    PubMed Central

    Finkelstein, Ruth

    2013-01-01

    Abscisic acid (ABA) is one of the “classical” plant hormones, i.e. discovered at least 50 years ago, that regulates many aspects of plant growth and development. This chapter reviews our current understanding of ABA synthesis, metabolism, transport, and signal transduction, emphasizing knowledge gained from studies of Arabidopsis. A combination of genetic, molecular and biochemical studies has identified nearly all of the enzymes involved in ABA metabolism, almost 200 loci regulating ABA response, and thousands of genes regulated by ABA in various contexts. Some of these regulators are implicated in cross-talk with other developmental, environmental or hormonal signals. Specific details of the ABA signaling mechanisms vary among tissues or developmental stages; these are discussed in the context of ABA effects on seed maturation, germination, seedling growth, vegetative stress responses, stomatal regulation, pathogen response, flowering, and senescence. PMID:24273463

  19. 21 CFR 556.590 - Salicylic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Salicylic acid. 556.590 Section 556.590 Food and... Residues of New Animal Drugs § 556.590 Salicylic acid. A tolerance of zero is established for residues of salicylic acid in milk from dairy animals....

  20. A review of toxicity from topical salicylic acid preparations.

    PubMed

    Madan, Raman K; Levitt, Jacob

    2014-04-01

    Topical salicylic acid is often used in dermatologic conditions because of its keratolytic, bacteriostatic, fungicidal, and photoprotective properties. The bioavailability of salicylic acid differs depending on the vehicle used and pH of transcellular fluids. Although rare, salicylic acid toxicity (salicylism) can occur from topical application. Physicians should be mindful of the potential for salicylism or even death from topically applied salicylic acid.

  1. Wet oxidation of salicylic acid solutions.

    PubMed

    Collado, Sergio; Garrido, Laura; Laca, Adriana; Diaz, Mario

    2010-11-15

    Salicylic acid is a frequent pollutant in several industrial wastewaters. Uncatalyzed wet air oxidation, which is a promising technique for the treatment of phenolic effluents, has not been analyzed yet for the removal of salicylic acid. The effect of different conditions of pH (1.3-12.3), pressure (1.0-4.1 MPa), temperature (413-443 K), and initial concentrations (1.45-14.50 mM) on the wet oxidation of salicylate/salicylic acid solutions have here been investigated. The pH value of the reaction media was found to be a key parameter for the rate of the oxidation process with an optimum at pH 3.1, when the concentrations of salicylic acid and salicylate were similar. The oxidation reaction followed pseudofirst-order kinetics with respect to salicylic acid and 0.82 order with respect to dissolved oxygen. Additionally, the evolution of the color during the wet oxidation was analyzed and discussed in relation with the formation of intermediate compounds. Then, a reaction pathway for the noncatalytic wet oxidation of the salicylic acid was proposed.

  2. Cross-talk in abscisic acid signaling

    NASA Technical Reports Server (NTRS)

    Fedoroff, Nina V.

    2002-01-01

    "Cross-talk" in hormone signaling reflects an organism's ability to integrate different inputs and respond appropriately, a crucial function at the heart of signaling network operation. Abscisic acid (ABA) is a plant hormone involved in bud and seed dormancy, growth regulation, leaf senescence and abscission, stomatal opening, and a variety of plant stress responses. This review summarizes what is known about ABA signaling in the control of stomatal opening and seed dormancy and provides an overview of emerging knowledge about connections between ABA, ethylene, sugar, and auxin synthesis and signaling.

  3. FCA does not bind abscisic acid.

    PubMed

    Risk, Joanna M; Macknight, Richard C; Day, Catherine L

    2008-12-11

    The RNA-binding protein FCA promotes flowering in Arabidopsis. Razem et al. reported that FCA is also a receptor for the phytohormone abscisic acid (ABA). However, we find that FCA does not bind ABA, suggesting that the quality of the proteins assayed and the sensitivity of the ABA-binding assay have led Razem et al. to erroneous conclusions. Because similar assays have been used to characterize other ABA receptors, our results indicate that the ABA-binding properties of these proteins should be carefully re-evaluated and that alternative ABA receptors are likely to be discovered.

  4. Infrared spectra of hydrogen-bonded salicylic acid and its derivatives : Salicylic acid and acetylsalicylic acid

    NASA Astrophysics Data System (ADS)

    Wójcik, Marek J.

    1981-11-01

    Infrared spectra of hydrogen-bonded salicylic acid, O-deutero-salicylic acid and acetylsalicylic acid crystals have been studied experimentally and theoretically. Interpretation of these spectra was based on the Witkowski-Maréchal model. Semi-quantitative agreement between experimental and theoretical spectra can be achieved with the simplest form of this model, with values of interaction parameters transferable for equivalent intermolecular hydrogen bonds.

  5. Salicylic Acid Biosynthesis and Metabolism

    PubMed Central

    Dempsey, D'Maris Amick; Vlot, A. Corina; Wildermuth, Mary C.; Klessig, Daniel F.

    2011-01-01

    Salicylic acid (SA) has been shown to regulate various aspects of growth and development; it also serves as a critical signal for activating disease resistance in Arabidopsis thaliana and other plant species. This review surveys the mechanisms involved in the biosynthesis and metabolism of this critical plant hormone. While a complete biosynthetic route has yet to be established, stressed Arabidopsis appear to synthesize SA primarily via an isochorismate-utilizing pathway in the chloroplast. A distinct pathway utilizing phenylalanine as the substrate also may contribute to SA accumulation, although to a much lesser extent. Once synthesized, free SA levels can be regulated by a variety of chemical modifications. Many of these modifications inactivate SA; however, some confer novel properties that may aid in long distance SA transport or the activation of stress responses complementary to those induced by free SA. In addition, a number of factors that directly or indirectly regulate the expression of SA biosynthetic genes or that influence the rate of SA catabolism have been identified. An integrated model, encompassing current knowledge of SA metabolism in Arabidopsis, as well as the influence other plant hormones exert on SA metabolism, is presented. PMID:22303280

  6. Abscisic acid: biosynthesis, inactivation, homoeostasis and signalling.

    PubMed

    Dong, Ting; Park, Youngmin; Hwang, Inhwan

    2015-01-01

    The phytohormone abscisic acid (ABA) plays crucial roles in numerous physiological processes during plant growth and abiotic stress responses. The endogenous ABA level is controlled by complex regulatory mechanisms involving biosynthesis, catabolism, transport and signal transduction pathways. This complex regulatory network may target multiple levels, including transcription, translation and post-translational regulation of genes involved in ABA responses. Most of the genes involved in ABA biosynthesis, catabolism and transport have been characterized. The local ABA concentration is critical for initiating ABA-mediated signalling during plant development and in response to environmental changes. In this chapter we discuss the mechanisms that regulate ABA biosynthesis, catabolism, transport and homoeostasis. We also present the findings of recent research on ABA perception by cellular receptors, and ABA signalling in response to cellular and environmental conditions.

  7. The second acidic constant of salicylic acid.

    PubMed

    Porto, Raffaella; De Tommaso, Gaetano; Furia, Emilia

    2005-01-01

    The second dissociation constant of salicylic acid (H2L) has been determined, at 25 degrees C, in NaCl ionic media by UV spectrophotometric measurements. The investigated ionic strength values were 0.16, 0.25, 0.50, 1.0, 2.0 and 3.0 M. The protolysis constants calculated at the different ionic strengths yielded, with the Specific Interaction Theory, the infinite dilution constant, log beta1(0) = 13.62 +/- 0.03, for the equilibrium L2- + H+ <==> HL-. The interaction coefficient between Na+ and L2-, b(Na+, L2-) = 0.02 +/- 0.07, has been also calculated.

  8. Abscisic Acid Transport in Human Erythrocytes*

    PubMed Central

    Vigliarolo, Tiziana; Guida, Lucrezia; Millo, Enrico; Fresia, Chiara; Turco, Emilia; De Flora, Antonio; Zocchi, Elena

    2015-01-01

    Abscisic acid (ABA) is a plant hormone involved in the response to environmental stress. Recently, ABA has been shown to be present and active also in mammals, where it stimulates the functional activity of innate immune cells, of mesenchymal and hemopoietic stem cells, and insulin-releasing pancreatic β-cells. LANCL2, the ABA receptor in mammalian cells, is a peripheral membrane protein that localizes at the intracellular side of the plasma membrane. Here we investigated the mechanism enabling ABA transport across the plasmamembrane of human red blood cells (RBC). Both influx and efflux of [3H]ABA occur across intact RBC, as detected by radiometric and chromatographic methods. ABA binds specifically to Band 3 (the RBC anion transporter), as determined by labeling of RBC membranes with biotinylated ABA. Proteoliposomes reconstituted with human purified Band 3 transport [3H]ABA and [35S]sulfate, and ABA transport is sensitive to the specific Band 3 inhibitor 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid. Once inside RBC, ABA stimulates ATP release through the LANCL2-mediated activation of adenylate cyclase. As ATP released from RBC is known to exert a vasodilator response, these results suggest a role for plasma ABA in the regulation of vascular tone. PMID:25847240

  9. GENETIC ANALYSIS OF ABSCISIC ACID BIOSYNTHESIS

    SciTech Connect

    MCCARTY D R

    2012-01-10

    The carotenoid cleavage dioxygenases (CCD) catalyze synthesis of a variety of apo-carotenoid secondary metabolites in plants, animals and bacteria. In plants, the reaction catalyzed by the 11, 12, 9-cis-epoxy carotenoid dioxygenase (NCED) is the first committed and key regulated step in synthesis of the plant hormone, abscisic acid (ABA). ABA is a key regulator of plant stress responses and has critical functions in normal root and seed development. The molecular mechanisms responsible for developmental control of ABA synthesis in plant tissues are poorly understood. Five of the nine CCD genes present in the Arabidopsis genome encode NCED's involved in control of ABA synthesis in the plant. This project is focused on functional analysis of these five AtNCED genes as a key to understanding developmental regulation of ABA synthesis and dissecting the role of ABA in plant development. For this purpose, the project developed a comprehensive set of gene knockouts in the AtNCED genes that facilitate genetic dissection of ABA synthesis. These mutants were used in combination with key molecular tools to address the following specific objectives: (1) the role of ABA synthesis in root development; (2) developmental control of ABA synthesis in seeds; (3) analysis of ATNCED over-expressers; (4) preliminary crystallography of the maize VP14 protein.

  10. Inhibitors of abscisic acid 8'-hydroxylase.

    PubMed

    Cutler, A J; Rose, P A; Squires, T M; Loewen, M K; Shaw, A C; Quail, J W; Krochko, J E; Abrams, S R

    2000-11-07

    Structural analogues of the phytohormone (+)-abscisic acid (ABA) have been synthesized and tested as inhibitors of the catabolic enzyme (+)-ABA 8'-hydroxylase. Assays employed microsomes from suspension-cultured corn cells. Four of the analogues [(+)-8'-acetylene-ABA, (+)-9'-propargyl-ABA, (-)-9'-propargyl-ABA, and (+)-9'-allyl-ABA] proved to be suicide substrates of ABA 8'-hydroxylase. For each suicide substrate, inactivation required NADPH, increased with time, and was blocked by addition of the natural substrate, (+)-ABA. The most effective suicide substrate was (+)-9'-propargyl-ABA (K(I) = 0.27 microM). Several analogues were competitive inhibitors of ABA 8'-hydroxylase, of which the most effective was (+)-8'-propargyl-ABA (K(i) = 1.1 microM). Enzymes in the microsomal extracts also hydroxylated (-)-ABA at the 7'-position at a low rate. This activity was not inhibited by the suicide substrates, showing that the 7'-hydroxylation of (-)-ABA was catalyzed by a different enzyme from that which catalyzed 8'-hydroxylation of (+)-ABA. Based on the results described, a simple model for the positioning of substrates in the active site of ABA 8'-hydroxylase is proposed. In a representative physiological assay, inhibition of Arabidopsis thaliana seed germination, (+)-9'-propargyl-ABA and (+)-8'-acetylene-ABA exhibited substantially stronger hormonal activity than (+)-ABA itself.

  11. Incorporation of oxygen into abscisic acid and phaseic acid for molecular oxygen

    SciTech Connect

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

    1984-05-01

    Abscisic acid accumulates in detached, wilted leaves of Xanthium strumariu. When these leaves are subsequently rehydrated, phaseic acid, a catabolite of abscisic acid, accumulates. Analysis by gas chromatography-mass spectrometry of phaseic acid isolated from stressed and subsequently rehydrated leaves placed in an atmosphere containing 20% /sup 18/O/sub 2/ and 80% N/sub 2/ indicates that one atom of /sup 18/O is incorporated in the 6'-hydroxymethyl group of phaseic acid. This suggests that the enzyme that converts abscisic acid to phaseic acid is an oxygenase. Analysis by gas chromatography-mass spectrometry of abscisic acid isolated from stressed leaves kept in an atmosphere containing /sup 18/O/sub 2/ indicates that one atom of /sup 18/O is presented in the carboxyl group of abscisic acid. Thus, when abscisic acid accumulates in water-streesed leaves, only one of the four oxygens present in the abscisic acid molecule is derived from molecular oxygen. This suggest that either (a) the oxygen present in the 1'-, 4'-, and one of the two oxygens at the 1-position of abscisic acid arise from water, or (b) there exists a stored precursor with oxygen atoms already present in the 1'- and 4'-positions of abscisic acid which is converted to abscisic acid under conditions of water stress. 17 references, 2 figures, 1 tables.

  12. Incorporation of oxygen into abscisic Acid and phaseic Acid from molecular oxygen.

    PubMed

    Creelman, R A; Zeevaart, J A

    1984-05-01

    Abscisic acid accumulates in detached, wilted leaves of Xanthium strumarium. When these leaves are subsequently rehydrated, phaseic acid, a catabolite of abscisic acid, accumulates. Analysis by gas chromatography-mass spectrometry of phaseic acid isolated from stressed and subsequently rehydrated leaves placed in an atmosphere containing 20% (18)O(2) and 80% N(2) indicates that one atom of (18)O is incorporated in the 6'-hydroxymethyl group of phaseic acid. This suggests that the enzyme that converts abscisic acid to phaseic acid is an oxygenase.Analysis by gas chromatography-mass spectrometry of abscisic acid isolated from stressed leaves kept in an atmosphere containing (18)O(2) indicates that one atom of (18)O is present in the carboxyl group of abscisic acid. Thus, when abscisic acid accumulates in water-stressed leaves, only one of the four oxygens present in the abscisic acid molecule is derived from molecular oxygen. This suggests that either (a) the oxygen present in the 1'-, 4'-, and one of the two oxygens at the 1-position of abscisic acid arise from water, or (b) there exists a stored precursor with oxygen atoms already present in the 1'- and 4'-positions of abscisic acid which is converted to abscisic acid under conditions of water stress.

  13. Abscisic acid uridine diphosphate glucosyltransferases play a crucial role in abscisic acid homeostasis in Arabidopsis.

    PubMed

    Dong, Ting; Xu, Zheng-Yi; Park, Youngmin; Kim, Dae Heon; Lee, Yongjik; Hwang, Inhwan

    2014-05-01

    The phytohormone abscisic acid (ABA) is crucial for plant growth and adaptive responses to various stress conditions. Plants continuously adjust the ABA level to meet physiological needs, but how ABA homeostasis occurs is not fully understood. This study provides evidence that UGT71B6, an ABA uridine diphosphate glucosyltransferase (UGT), and its two closely related homologs, UGT71B7 and UGT71B8, play crucial roles in ABA homeostasis and in adaptation to dehydration, osmotic stress, and high-salinity stresses in Arabidopsis (Arabidopsis thaliana). UGT RNA interference plants that had low levels of these three UGT transcripts displayed hypersensitivity to exogenous ABA and high-salt conditions during germination and exhibited a defect in plant growth. However, the ectopic expression of UGT71B6 in the atbg1 (for β-glucosidase) mutant background aggravated the ABA-deficient phenotype of atbg1 mutant plants. In addition, modulation of the expression of the three UGTs affects the expression of CYP707A1 to CYP707A4, which encode ABA 8'-hydroxylases; four CYP707As were expressed at higher levels in the UGT RNA interference plants but at lower levels in the UGT71B6:GFP-overexpressing plants. Based on these data, this study proposes that UGT71B6 and its two homologs play a critical role in ABA homeostasis by converting active ABA to an inactive form (abscisic acid-glucose ester) depending on intrinsic cellular and environmental conditions in plants.

  14. Biosynthesis and metabolism of salicylic acid.

    PubMed Central

    Lee, H I; León, J; Raskin, I

    1995-01-01

    Pathways of salicylic acid (SA) biosynthesis and metabolism in tobacco have been recently identified. SA, an endogenous regulator of disease resistance, is a product of phenylpropanoid metabolism formed via decarboxylation of trans-cinnamic acid to benzoic acid and its subsequent 2-hydroxylation to SA. In tobacco mosaic virus-inoculated tobacco leaves, newly synthesized SA is rapidly metabolized to SA O-beta-D-glucoside and methyl salicylate. Two key enzymes involved in SA biosynthesis and metabolism: benzoic acid 2-hydroxylase, which converts benzoic acid to SA, and UDPglucose:SA glucosyltransferase (EC 2.4.1.35), which catalyzes conversion of SA to SA glucoside have been partially purified and characterized. Progress in enzymology and molecular biology of SA biosynthesis and metabolism will provide a better understanding of signal transduction pathway involved in plant disease resistance. PMID:11607533

  15. Biosynthesis and metabolism of salicylic acid

    SciTech Connect

    Lee, H.; Leon, J.; Raskin, I.

    1995-05-09

    Pathways of salicylic acid (SA) biosynthesis and metabolism in tobacco have been recently identified. SA, an endogenous regulator of disease resistance, is a product of phenylpropanoid metabolism formed via decarboxylation of trans-cinnamic acid to benzoic acid and its subsequent 2-hydroxylation to SA. In tobacco mosaic virus-inoculated tobacco leaves, newly synthesized SA is rapidly metabolized to SA O-{beta}-D-glucoside and methyl salicylate. Two key enzymes involved in SA biosynthesis and metabolism: benzoic acid 2-hydroxylase, which converts benzoic acid to SA, and UDPglucose:SA glucosyltransferase (EC 2.4.1.35), which catalyzes conversion of SA to SA glucoside have been partially purified and characterized. Progress in enzymology and molecular biology of SA biosynthesis and metabolism will provide a better understanding of signal transduction pathway involved in plant disease resistance. 62 refs., 1 fig.

  16. E3 ubiquitin ligases and abscisic acid signaling

    PubMed Central

    Liu, Hongxia

    2011-01-01

    The ubiquitin proteasome system is involved in the regulation of nearly every aspect of plant growth and development. Protein ubiquitination involves the covalent attachment of ubiquitin to target proteins through a cascade catalyzed by three enzymes known as E1, E2 and E3. E3s are of particular interest as they confer substrate specificity during ubiquitination through their diverse substrate recognition domains. Recently, a number of E3s have been identified that actively participate in abscisic acid hormone biology, including regulation of biosynthesis, de-repression or activation of abscisic acid response and degradation of signaling components. In this review, we summarize recent exciting studies of the different types of E3s that target specific mediators of abscisic acid signaling or affect the plants response to the hormone. PMID:21364320

  17. Plant Hormone Salicylic Acid Produced by a Malaria Parasite Controls Host Immunity and Cerebral Malaria Outcome.

    PubMed

    Matsubara, Ryuma; Aonuma, Hiroka; Kojima, Mikiko; Tahara, Michiru; Andrabi, Syed Bilal Ahmad; Sakakibara, Hitoshi; Nagamune, Kisaburo

    2015-01-01

    The apicomplexan parasite Toxoplasma gondii produces the plant hormone abscisic acid, but it is unclear if phytohormones are produced by the malaria parasite Plasmodium spp., the most important parasite of this phylum. Here, we report detection of salicylic acid, an immune-related phytohormone of land plants, in P. berghei ANKA and T. gondii cell lysates. However, addition of salicylic acid to P. falciparum and T. gondii culture had no effect. We transfected P. falciparum 3D7 with the nahG gene, which encodes a salicylic acid-degrading enzyme isolated from plant-infecting Pseudomonas sp., and established a salicylic acid-deficient mutant. The mutant had a significantly decreased concentration of parasite-synthesized prostaglandin E2, which potentially modulates host immunity as an adaptive evolution of Plasmodium spp. To investigate the function of salicylic acid and prostaglandin E2 on host immunity, we established P. berghei ANKA mutants expressing nahG. C57BL/6 mice infected with nahG transfectants developed enhanced cerebral malaria, as assessed by Evans blue leakage and brain histological observation. The nahG-transfectant also significantly increased the mortality rate of mice. Prostaglandin E2 reduced the brain symptoms by induction of T helper-2 cytokines. As expected, T helper-1 cytokines including interferon-γ and interleukin-2 were significantly elevated by infection with the nahG transfectant. Thus, salicylic acid of Plasmodium spp. may be a new pathogenic factor of this threatening parasite and may modulate immune function via parasite-produced prostaglandin E2.

  18. [Tissue culture of medicinal plant and abscisic acid].

    PubMed

    Fang, Hui-Yong; Zhu, Hong; Yao, Jian-Xun; Jia, Cai-Feng; Shan, Gao-Wei; Li, Min-Hui

    2013-01-01

    Abscisic acid (ABA) plays a key role in many physiological processes of plants, and it was also applied to fields of medicinal plant biotechnology. The article presents a review of some recent application of ABA in enhancing the production of secondary metabolites of medicinal plants, improving the in vitro conservation in medicinal plant tissue culture system.

  19. Overexpression of a soybean salicylic acid methyltransferase gene confers resistance to soybean cyst nematode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salicylic acid plays a critical role in activating plant defence responses after pathogen attack. Salicylic acid methyltransferase (SAMT) modulates the level of salicylic acid by converting salicylic acid to methyl salicylate. Here, we report that a SAMT gene from soybean (GmSAMT1) plays a role in s...

  20. Abscisic acid has a key role in modulating diverse plant-pathogen interactions.

    PubMed

    Fan, Jun; Hill, Lionel; Crooks, Casey; Doerner, Peter; Lamb, Chris

    2009-08-01

    We isolated an activation-tagged Arabidopsis (Arabidopsis thaliana) line, constitutive disease susceptibility2-1D (cds2-1D), that showed enhanced bacterial growth when challenged with various Pseudomonas syringae strains. Systemic acquired resistance and systemic PATHOGENESIS-RELATED GENE1 induction were also compromised in cds2-1D. The T-DNA insertion adjacent to NINE-CIS-EPOXYCAROTENOID DIOXYGENASE5 (NCED5), one of six genes encoding the abscisic acid (ABA) biosynthetic enzyme NCED, caused a massive increase in transcript level and enhanced ABA levels >2-fold. Overexpression of NCED genes recreated the enhanced disease susceptibility phenotype. NCED2, NCED3, and NCED5 were induced, and ABA accumulated strongly following compatible P. syringae infection. The ABA biosynthetic mutant aba3-1 showed reduced susceptibility to virulent P. syringae, and ABA, whether through exogenous application or endogenous accumulation in response to mild water stress, resulted in increased bacterial growth following challenge with virulent P. syringae, indicating that ABA suppresses resistance to P. syringae. Likewise ABA accumulation also compromised resistance to the biotrophic oomycete Hyaloperonospora arabidopsis, whereas resistance to the fungus Alternaria brassicicola was enhanced in cds2-1D plants and compromised in aba3-1 plants, indicating that ABA promotes resistance to this necrotroph. Comparison of the accumulation of salicylic acid and jasmonic acid in the wild type, cds2-1D, and aba3-1 plants challenged with P. syringae showed that ABA promotes jasmonic acid accumulation and exhibits a complex antagonistic relationship with salicylic acid. Our findings provide genetic evidence that the abiotic stress signal ABA also has profound roles in modulating diverse plant-pathogen interactions mediated at least in part by cross talk with the jasmonic acid and salicylic acid biotic stress signal pathways.

  1. Response of Cultured Maize Cells to (+)-Abscisic Acid, (-)-Abscisic Acid, and Their Metabolites.

    PubMed Central

    Balsevich, J. J.; Cutler, A. J.; Lamb, N.; Friesen, L. J.; Kurz, E. U.; Perras, M. R.; Abrams, S. R.

    1994-01-01

    The metabolism and effects of (+)-S- and (-)-R-abscisic acid (ABA) and some metabolites were studied in maize (Zea mays L. cv Black Mexican Sweet) suspension-cultured cells. Time-course studies of metabolite formation were performed in both cells and medium via analytical high-performance liquid chromatography. Metabolites were isolated and identified using physical and chemical methods. At 10 [mu]M concentration and 28[deg] C, (+)-ABA was metabolized within 24 h, yielding natural (-)-phaseic acid [(-)-PA] as the major product. The unnatural enantiomer (-)-ABA was less than 50% metabolized within 24 h and gave primarily (-)-7[prime]-hydroxyABA [(-)-7[prime]-HOABA], together with (+)-PA and ABA glucose ester. The distribution of metabolites in cells and medium was different, reflecting different sites of metabolism and membrane permeabilities of conjugated and nonconjugated metabolites. The results imply that (+)-ABA was oxidized to (-)-PA inside the cell, whereas (-)-ABA was converted to (-)-7[prime]-HOABA at the cell surface. Growth of maize cells was inhibited by both (+)- and (-)-ABA, with only weak contributions from their metabolites. The concentration of (+)-ABA that caused a 50% inhibition of growth of maize cells was approximately 1 [mu]M, whereas that for its metabolite (-)-PA was approximately 50 [mu]M. (-)-ABA was less active than (+)-ABA, with 50% growth inhibition observed at about 10 [mu]M. (-)-7[prime]-HOABA was only weakly active, with 50% inhibition caused by approximately 500 [mu]M. Time-course studies of medium pH indicated that (+)-ABA caused a transient pH increase (+0.3 units) at 6 h after addition that was not observed in controls or in samples treated with (-)-PA. The effect of (-)-ABA on medium Ph was marginal. No racemization at C-1[prime] of (+)-ABA, (-)-ABA, or metabolites was observed during the studies. PMID:12232311

  2. Salicylic Acid and Sodium Salicylate Alleviate Cadmium Toxicity to Different Extents in Maize (Zea mays L.).

    PubMed

    Gondor, Orsolya Kinga; Pál, Magda; Darkó, Éva; Janda, Tibor; Szalai, Gabriella

    2016-01-01

    The role of salicylic acid in Cd tolerance has attracted more attention recently but no information is available on the efficiency of different forms of salicylic acid. The aim was thus to investigate whether both the acid and salt forms of salicylic acid provide protection against Cd stress and to compare their mode of action. Young maize plants were grown under controlled environmental conditions. One group of 10-day-old seedlings were treated with 0.5 mM SA or NaSA for 1 day then half of the pants were treated with 0.5 mM Cd for 1 day. Another group of seedlings was treated with 0.5 mM CdSO4 for 1 day without pre-treatment with SA or NaSA, while a third group was treated simultaneously with Cd and either SA or NaSA. Both salicylic acid forms reduced the Cd accumulation in the roots. Treatment with the acidic form meliorated the Cd accumulation in the leaves, while Na-salicylate increased the phytochelatin level in the roots and the amount of salicylic acid in the leaves. Furthermore, increased antioxidant enzyme activity was mainly induced by the acid form, while glutathione-related redox changes were influenced mostly by the salt form. The acidic and salt forms of salicylic acid affected the two antioxidant systems in different ways, and the influence of these two forms on the distribution and detoxification of Cd also differed. The present results also draw attention to the fact that generalisations about the stress protective mechanisms induced by salicylic acid are misleading since different forms of SA may exert different effects on the plants via separate mechanisms.

  3. Salicylic Acid and Sodium Salicylate Alleviate Cadmium Toxicity to Different Extents in Maize (Zea mays L.)

    PubMed Central

    Gondor, Orsolya Kinga; Pál, Magda; Darkó, Éva; Janda, Tibor; Szalai, Gabriella

    2016-01-01

    The role of salicylic acid in Cd tolerance has attracted more attention recently but no information is available on the efficiency of different forms of salicylic acid. The aim was thus to investigate whether both the acid and salt forms of salicylic acid provide protection against Cd stress and to compare their mode of action. Young maize plants were grown under controlled environmental conditions. One group of 10-day-old seedlings were treated with 0.5 mM SA or NaSA for 1 day then half of the pants were treated with 0.5 mM Cd for 1 day. Another group of seedlings was treated with 0.5 mM CdSO4 for 1 day without pre-treatment with SA or NaSA, while a third group was treated simultaneously with Cd and either SA or NaSA. Both salicylic acid forms reduced the Cd accumulation in the roots. Treatment with the acidic form meliorated the Cd accumulation in the leaves, while Na-salicylate increased the phytochelatin level in the roots and the amount of salicylic acid in the leaves. Furthermore, increased antioxidant enzyme activity was mainly induced by the acid form, while glutathione-related redox changes were influenced mostly by the salt form. The acidic and salt forms of salicylic acid affected the two antioxidant systems in different ways, and the influence of these two forms on the distribution and detoxification of Cd also differed. The present results also draw attention to the fact that generalisations about the stress protective mechanisms induced by salicylic acid are misleading since different forms of SA may exert different effects on the plants via separate mechanisms. PMID:27490102

  4. Salicylic acid content of spices and its implications.

    PubMed

    Paterson, John R; Srivastava, Rajeev; Baxter, Gwen J; Graham, Alan B; Lawrence, James R

    2006-04-19

    This work was done to determine the salicylate content of a variety of commonly used spices and to assess whether this potential dietary source of salicylate was bioavailable. Spices, Indian cooked dishes, and blood and urine samples taken after ingestion of a test meal were investigated for their salicylate content using high-performance liquid chromatography with electrochemical detection. The serum salicylic acid concentrations in samples from villagers in southern India were also measured and have been compared with typical European values. Salicylic acid was determined in all spices (up to 1.5 wt %) and cooked dishes. The salicylate content of blood and urine was shown to increase following consumption of the meal, indicating that this dietary source of salicylic acid was bioavailable. Salicylic acid levels in the serum from rural Indians were significantly (median almost 3-fold) higher than values previously measured in Western vegetarians. Chemoprotective aspirin is rapidly hydrolyzed to salicylic acid, and this phytochemical may contribute to the low cancer incidence in rural India.

  5. Overexpression of salicylic acid carboxyl methyltransferase reduces salicylic acid-mediated pathogen resistance in Arabidopsis thaliana.

    PubMed

    Koo, Yeon Jong; Kim, Myeong Ae; Kim, Eun Hye; Song, Jong Tae; Jung, Choonkyun; Moon, Joon-Kwan; Kim, Jeong-Han; Seo, Hak Soo; Song, Sang Ik; Kim, Ju-Kon; Lee, Jong Seob; Cheong, Jong-Joo; Choi, Yang Do

    2007-05-01

    We cloned a salicylic acid/benzoic acid carboxyl methyltransferase gene, OsBSMT1, from Oryza sativa. A recombinant OsBSMT1 protein obtained by expressing the gene in Escherichia coli exhibited carboxyl methyltransferase activity in reactions with salicylic acid (SA), benzoic acid (BA), and de-S-methyl benzo(1,2,3)thiadiazole-7-carbothioic acid (dSM-BTH), producing methyl salicylate (MeSA), methyl benzoate (MeBA), and methyl dSM-BTH (MeBTH), respectively. Compared to wild-type plants, transgenic Arabidopsis overexpressing OsBSMT1 accumulated considerably higher levels of MeSA and MeBA, some of which were vaporized into the environment. Upon infection with the bacterial pathogen Pseudomonas syringae or the fungal pathogen Golovinomyces orontii, transgenic plants failed to accumulate SA and its glucoside (SAG), becoming more susceptible to disease than wild-type plants. OsBSMT1-overexpressing Arabidopsis showed little induction of PR-1 when treated with SA or G. orontii. Notably, incubation with the transgenic plant was sufficient to trigger PR-1 induction in neighboring wild-type plants. Together, our results indicate that in the absence of SA, MeSA alone cannot induce a defense response, yet it serves as an airborne signal for plant-to-plant communication. We also found that jasmonic acid (JA) induced AtBSMT1, which may contribute to an antagonistic effect on SA signaling pathways by depleting the SA pool in plants.

  6. Salicylic acid as a peeling agent: a comprehensive review.

    PubMed

    Arif, Tasleem

    2015-01-01

    Salicylic acid has been used to treat various skin disorders for more than 2,000 years. The ability of salicylic acid to exfoliate the stratum corneum makes it a good agent for peeling. In particular, the comedolytic property of salicylic acid makes it a useful peeling agent for patients with acne. Once considered as a keratolytic agent, the role of salicylic acid as a desmolytic agent, because of its ability to disrupt cellular junctions rather than breaking or lysing intercellular keratin filaments, is now recognized and is discussed here. Salicylic acid as a peeling agent has a number of indications, including acne vulgaris, melasma, photodamage, freckles, and lentigines. The efficacy and safety of salicylic acid peeling in Fitzpatrick skin types I-III as well as in skin types V and VI have been well documented in the literature. This paper reviews the available data and literature on salicylic acid as a peeling agent and its possible indications. Its properties, efficacy and safety, the peeling procedure, and possible side effects are discussed in detail. An account of salicylism is also included.

  7. Salicylic acid as a peeling agent: a comprehensive review

    PubMed Central

    Arif, Tasleem

    2015-01-01

    Salicylic acid has been used to treat various skin disorders for more than 2,000 years. The ability of salicylic acid to exfoliate the stratum corneum makes it a good agent for peeling. In particular, the comedolytic property of salicylic acid makes it a useful peeling agent for patients with acne. Once considered as a keratolytic agent, the role of salicylic acid as a desmolytic agent, because of its ability to disrupt cellular junctions rather than breaking or lysing intercellular keratin filaments, is now recognized and is discussed here. Salicylic acid as a peeling agent has a number of indications, including acne vulgaris, melasma, photodamage, freckles, and lentigines. The efficacy and safety of salicylic acid peeling in Fitzpatrick skin types I–III as well as in skin types V and VI have been well documented in the literature. This paper reviews the available data and literature on salicylic acid as a peeling agent and its possible indications. Its properties, efficacy and safety, the peeling procedure, and possible side effects are discussed in detail. An account of salicylism is also included. PMID:26347269

  8. Salicylic acid deficiency in NahG transgenic lines and sid2 mutants increases seed yield in the annual plant Arabidopsis thaliana.

    PubMed

    Abreu, Maria Elizabeth; Munné-Bosch, Sergi

    2009-01-01

    Salicylic acid-deficient NahG transgenic lines and sid2 mutants were used to evaluate the role of this compound in the development of the short-lived, annual plant Arabidopsis thaliana, with a particular focus on the interplay between salicylic acid and other phytohormones. Low salicylic acid levels led to increased growth, as well as to smaller abscisic acid levels and reduced damage to PSII (as indicated by F(v)/F(m) ratios) during the reproductive stages in rosette leaves of NahG transgenic lines and sid2 mutants, compared with wild-type plants. Furthermore, salicylic acid deficiency highly influenced seed yield and composition. Seed production increased by 4.4-fold and 3.5-fold in NahG transgenic lines and sid2 mutants, respectively, compared to the wild type. Salicylic acid deficiency also improved seed composition in terms of antioxidant vitamin concentrations, seeds of salicylic acid-deficient plants showing higher levels of alpha- and gamma-tocopherol (vitamin E) and beta-carotene (pro-vitamin A) than seeds of wild-type plants. Seeds of salicylic acid-deficient plants also showed higher nitrogen concentrations than seeds of wild-type plants. It is concluded that (i) the sid2 gene, which encodes for isochorismate synthase, plays a central role in salicylic acid biosynthesis during plant development in A. thaliana, (ii) salicylic acid plays a role in the regulation of growth, senescence, and seed production, (iii) there is a cross-talk between salicylic acid and other phytohormones during plant development, and (iv) the concentrations of antioxidant vitamins in seeds may be influenced by the endogenous levels of salicylic acid in plants.

  9. Development of Inhibitors of Salicylic Acid Signaling.

    PubMed

    Jiang, Kai; Kurimoto, Tetsuya; Seo, Eun-kyung; Miyazaki, Sho; Nakajima, Masatoshi; Nakamura, Hidemitsu; Asami, Tadao

    2015-08-19

    Salicylic acid (SA) plays important roles in the induction of systemic acquired resistance (SAR) in plants. Determining the mechanism of SAR will extend our understanding of plant defenses against pathogens. We recently reported that PAMD is an inhibitor of SA signaling, which suppresses the expression of the pathogenesis-related PR genes and is expected to facilitate the understanding of SA signaling. However, PAMD strongly inhibits plant growth. To minimize the side effects of PAMD, we synthesized a number of PAMD derivatives, and identified compound 4 that strongly suppresses the expression of the PR genes with fewer adverse effects on plant growth than PAMD. We further showed that the adverse effects on plant growth were partially caused the stabilization of DELLA, which is also related to the pathogen responses. These results indicate that compound 4 would facilitate our understanding of SA signaling and its cross talk with other plant hormones.

  10. Interactions of salicylic acid derivatives with calcite crystals.

    PubMed

    Ukrainczyk, Marko; Gredičak, Matija; Jerić, Ivanka; Kralj, Damir

    2012-01-01

    Investigation of basic interactions between the active pharmaceutical compounds and calcium carbonates is of great importance because of the possibility to use the carbonates as a mineral carrier in drug delivery systems. In this study the mode and extent of interactions of salicylic acid and its amino acid derivates, chosen as pharmaceutically relevant model compounds, with calcite crystals are described. Therefore, the crystal growth kinetics of well defined rhombohedral calcite seed crystals in the systems containing salicylic acid (SA), 5-amino salicylic acid (5-ASA), N-salicyloil-l-aspartic acid (N-Sal-Asp) or N-salicyloil-l-glutamic acid (N-Sal-Glu), were investigated. The precipitation systems were of relatively low initial supersaturation and of apparently neutral pH. The data on the crystal growth rate reductions in the presence of the applied salicylate molecules were analyzed by means of Cabrera & Vermileya's, and Kubota & Mullin's models of interactions of the dissolved additives and crystal surfaces. The crystal growth kinetic experiments were additionally supported with the appropriate electrokinetic, spectroscopic and adsorption measurements. The Langmuir adsorption constants were determined and they were found to be in a good correlation with values obtained from crystal growth kinetic analyses. The results indicated that salicylate molecules preferentially adsorb along the steps on the growing calcite surfaces. The values of average spacing between the adjacent salicylate adsorption active sites and the average distance between the neighboring adsorbed salicylate molecules were also estimated.

  11. Mechanisms of abscisic acid-mediated control of stomatal aperture.

    PubMed

    Munemasa, Shintaro; Hauser, Felix; Park, Jiyoung; Waadt, Rainer; Brandt, Benjamin; Schroeder, Julian I

    2015-12-01

    Drought stress triggers an increase in the level of the plant hormone abscisic acid (ABA), which initiates a signaling cascade to close stomata and reduce water loss. Recent studies have revealed that guard cells control cytosolic ABA concentration through the concerted actions of biosynthesis, catabolism as well as transport across membranes. Substantial progress has been made at understanding the molecular mechanisms of how the ABA signaling core module controls the activity of anion channels and thereby stomatal aperture. In this review, we focus on our current mechanistic understanding of ABA signaling in guard cells including the role of the second messenger Ca(2+) as well as crosstalk with biotic stress responses.

  12. Uprooting an abscisic acid paradigm: Shoots are the primary source.

    PubMed

    McAdam, Scott A M; Manzi, Matías; Ross, John J; Brodribb, Timothy J; Gómez-Cadenas, Aurelio

    2016-06-02

    In the past, a conventional wisdom has been that abscisic acid (ABA) is a xylem-transported hormone that is synthesized in the roots, while acting in the shoot to close stomata in response to a decrease in plant water status. Now, however, evidence from two studies, which we have conducted independently, challenges this root-sourced ABA paradigm. We show that foliage-derived ABA has a major influence over root development and that leaves are the predominant location for ABA biosynthesis during drought stress.

  13. Signalling of abscisic acid to regulate plant growth.

    PubMed Central

    Himmelbach, A; Iten, M; Grill, E

    1998-01-01

    Abscisic acid (ABA) mediated growth control is a fundamental response of plants to adverse environmental cues. The linkage between ABA perception and growth control is currently being unravelled by using different experimental approaches such as mutant analysis and microinjection experiments. So far, two protein phosphatases, ABI1 and ABI2, cADPR, pH, and Ca2+ have been identified as main components of the ABA signalling pathway. Here, the ABA signal transduction pathway is compared to signalling cascades from yeast and mammalian cells. A model for a bifurcated ABA signal transduction pathway exerting a positive and negative control mechanism is proposed. PMID:9800207

  14. Salicylic acid induces mitochondrial injury by inhibiting ferrochelatase heme biosynthesis activity.

    PubMed

    Gupta, Vipul; Liu, Shujie; Ando, Hideki; Ishii, Ryohei; Tateno, Shumpei; Kaneko, Yuki; Yugami, Masato; Sakamoto, Satoshi; Yamaguchi, Yuki; Nureki, Osamu; Handa, Hiroshi

    2013-12-01

    Salicylic acid is a classic nonsteroidal anti-inflammatory drug. Although salicylic acid also induces mitochondrial injury, the mechanism of its antimitochondrial activity is not well understood. In this study, by using a one-step affinity purification scheme with salicylic acid-immobilized beads, ferrochelatase (FECH), a homodimeric enzyme involved in heme biosynthesis in mitochondria, was identified as a new molecular target of salicylic acid. Moreover, the cocrystal structure of the FECH-salicylic acid complex was determined. Structural and biochemical studies showed that salicylic acid binds to the dimer interface of FECH in two possible orientations and inhibits its enzymatic activity. Mutational analysis confirmed that Trp301 and Leu311, hydrophobic amino acid residues located at the dimer interface, are directly involved in salicylic acid binding. On a gel filtration column, salicylic acid caused a shift in the elution profile of FECH, indicating that its conformational change is induced by salicylic acid binding. In cultured human cells, salicylic acid treatment or FECH knockdown inhibited heme synthesis, whereas salicylic acid did not exert its inhibitory effect in FECH knockdown cells. Concordantly, salicylic acid treatment or FECH knockdown inhibited heme synthesis in zebrafish embryos. Strikingly, the salicylic acid-induced effect in zebrafish was partially rescued by FECH overexpression. Taken together, these findings illustrate that FECH is responsible for salicylic acid-induced inhibition of heme synthesis, which may contribute to its antimitochondrial and anti-inflammatory function. This study establishes a novel aspect of the complex pharmacological effects of salicylic acid.

  15. An Abscisic Acid-Independent Oxylipin Pathway Controls Stomatal Closure and Immune Defense in Arabidopsis

    PubMed Central

    Mondy, Samuel; Tranchimand, Sylvain; Rumeau, Dominique; Boudsocq, Marie; Garcia, Ana Victoria; Douki, Thierry; Bigeard, Jean; Laurière, Christiane; Chevalier, Anne; Castresana, Carmen; Hirt, Heribert

    2013-01-01

    Plant stomata function in innate immunity against bacterial invasion and abscisic acid (ABA) has been suggested to regulate this process. Using genetic, biochemical, and pharmacological approaches, we demonstrate that (i) the Arabidopsis thaliana nine-specific-lipoxygenase encoding gene, LOX1, which is expressed in guard cells, is required to trigger stomatal closure in response to both bacteria and the pathogen-associated molecular pattern flagellin peptide flg22; (ii) LOX1 participates in stomatal defense; (iii) polyunsaturated fatty acids, the LOX substrates, trigger stomatal closure; (iv) the LOX products, fatty acid hydroperoxides, or reactive electrophile oxylipins induce stomatal closure; and (v) the flg22-mediated stomatal closure is conveyed by both LOX1 and the mitogen-activated protein kinases MPK3 and MPK6 and involves salicylic acid whereas the ABA-induced process depends on the protein kinases OST1, MPK9, or MPK12. Finally, we show that the oxylipin and the ABA pathways converge at the level of the anion channel SLAC1 to regulate stomatal closure. Collectively, our results demonstrate that early biotic signaling in guard cells is an ABA-independent process revealing a novel function of LOX1-dependent stomatal pathway in plant immunity. PMID:23526882

  16. Tomato ABSCISIC ACID STRESS RIPENING (ASR) gene family revisited.

    PubMed

    Golan, Ido; Dominguez, Pia Guadalupe; Konrad, Zvia; Shkolnik-Inbar, Doron; Carrari, Fernando; Bar-Zvi, Dudy

    2014-01-01

    Tomato ABSCISIC ACID RIPENING 1 (ASR1) was the first cloned plant ASR gene. ASR orthologs were then cloned from a large number of monocot, dicot and gymnosperm plants, where they are mostly involved in response to abiotic (drought and salinity) stress and fruit ripening. The tomato genome encodes five ASR genes: ASR1, 2, 3 and 5 encode low-molecular-weight proteins (ca. 110 amino acid residues each), whereas ASR4 encodes a 297-residue polypeptide. Information on the expression of the tomato ASR gene family is scarce. We used quantitative RT-PCR to assay the expression of this gene family in plant development and in response to salt and osmotic stresses. ASR1 and ASR4 were the main expressed genes in all tested organs and conditions, whereas ASR2 and ASR3/5 expression was two to three orders of magnitude lower (with the exception of cotyledons). ASR1 is expressed in all plant tissues tested whereas ASR4 expression is limited to photosynthetic organs and stamens. Essentially, ASR1 accounted for most of ASR gene expression in roots, stems and fruits at all developmental stages, whereas ASR4 was the major gene expressed in cotyledons and young and fully developed leaves. Both ASR1 and ASR4 were expressed in flower organs, with ASR1 expression dominating in stamens and pistils, ASR4 in sepals and petals. Steady-state levels of ASR1 and ASR4 were upregulated in plant vegetative organs following exposure to salt stress, osmotic stress or the plant abiotic stress hormone abscisic acid (ABA). Tomato plants overexpressing ASR1 displayed enhanced survival rates under conditions of water stress, whereas ASR1-antisense plants displayed marginal hypersensitivity to water withholding.

  17. Chemical genetics reveals negative regulation of abscisic acid signaling by a plant immune response pathway.

    PubMed

    Kim, Tae-Houn; Hauser, Felix; Ha, Tracy; Xue, Shaowu; Böhmer, Maik; Nishimura, Noriyuki; Munemasa, Shintaro; Hubbard, Katharine; Peine, Nora; Lee, Byeong-Ha; Lee, Stephen; Robert, Nadia; Parker, Jane E; Schroeder, Julian I

    2011-06-07

    Coordinated regulation of protection mechanisms against environmental abiotic stress and pathogen attack is essential for plant adaptation and survival. Initial abiotic stress can interfere with disease-resistance signaling [1-6]. Conversely, initial plant immune signaling may interrupt subsequent abscisic acid (ABA) signal transduction [7, 8]. However, the processes involved in this crosstalk between these signaling networks have not been determined. By screening a 9600-compound chemical library, we identified a small molecule [5-(3,4-dichlorophenyl)furan-2-yl]-piperidine-1-ylmethanethione (DFPM) that rapidly downregulates ABA-dependent gene expression and also inhibits ABA-induced stomatal closure. Transcriptome analyses show that DFPM also stimulates expression of plant defense-related genes. Major early regulators of pathogen-resistance responses, including EDS1, PAD4, RAR1, and SGT1b, are required for DFPM-and notably also for Pseudomonas-interference with ABA signal transduction, whereas salicylic acid, EDS16, and NPR1 are not necessary. Although DFPM does not interfere with early ABA perception by PYR/RCAR receptors or ABA activation of SnRK2 kinases, it disrupts cytosolic Ca(2+) signaling and downstream anion channel activation in a PAD4-dependent manner. Our findings provide evidence that activation of EDS1/PAD4-dependent plant immune responses rapidly disrupts ABA signal transduction and that this occurs at the level of Ca(2+) signaling, illuminating how the initial biotic stress pathway interferes with ABA signaling.

  18. Abscisic Acid: a versatile phytohormone in plant signaling and beyond.

    PubMed

    Gomez-Cadenas, Aurelio; Vives, Vicente; Zandalinas, Sara I; Manzi, Matias; Sanchez-Perez, Ana M; Perez-Clemente, Rosa M; Arbona, Vicent

    2015-01-01

    As sessile organisms, plants cannot escape from adverse conditions and, therefore, they have developed complex responses to the changing environment. Plant responses to abiotic cues involve changes in metabolism, photosynthesis, gene expression, ion levels, etc., and must be perfectly coordinated by phytohormones. The abscisic acid (ABA) is the main phytohormone involved in abiotic stress responses although it is nowadays clear that its signaling pathways are not isolated but interconnected with other hormone signals in complex networks. This article revises molecular mechanisms involved in the crosstalks of ABA with other phytohormones in response to different physiological processes. Moreover, ABA is not a molecule exclusive from plants but it can be found in many other organisms including bacteria, algae, fungi, animals, etc. Interestingly, it can be synthesized and secreted by a variety of human cells. These aspects that confer to the ABA a range of ubiquitous molecule will be also revised in this article.

  19. The role of brassinosteroids and abscisic acid in stomatal development.

    PubMed

    Serna, Laura

    2014-08-01

    Gas exchange with the atmosphere is regulated through the stomata. This process relies on both the degree and duration of stomatal opening, and the number and patterning of these structures in the plant surface. Recent work has revealed that brassinosteroids and abscisic acid (ABA), which control stomatal opening, also repress stomatal development in cotyledons and leaves of at least some plants. It is speculated that, in Arabidopsis, these phytohormones control the same steps of this developmental process, most probably, through the regulation of the same mitogen-activated protein (MAP) kinase module. The conservation, in seeds plants, of components downstream of this module with MAP kinase target domains, suggests that these proteins are also regulated by these cascades, which, in turn, may be regulated by brassinosteroids and/or ABA.

  20. Abscisic acid and pyrabactin improve vitamin C contents in raspberries.

    PubMed

    Miret, Javier A; Munné-Bosch, Sergi

    2016-07-15

    Abscisic acid (ABA) is a plant growth regulator with roles in senescence, fruit ripening and environmental stress responses. ABA and pyrabactin (a non-photosensitive ABA agonist) effects on red raspberry (Rubus idaeus L.) fruit development (including ripening) were studied, with a focus on vitamin and antioxidant composition. Application of ABA and/or pyrabactin just after fruit set did not affect the temporal pattern of fruit development and ripening; neither provitamin A (carotenoids) nor vitamin E contents were modified. In contrast, ABA and pyrabactin altered the vitamin C redox state at early stages of fruit development and more than doubled vitamin C contents at the end of fruit ripening. These were partially explained by changes in ascorbate oxidation and recycling. Therefore, ABA and pyrabactin applications may be used to increase vitamin C content of ripe fruits, increasing fruit quality and value. However, treatments containing pyrabactin-combined with ABA or alone-diminished protein content, thus partially limiting its potential applicability.

  1. Regulation of hormone metabolism in Arabidopsis seeds: phytochrome regulation of abscisic acid metabolism and abscisic acid regulation of gibberellin metabolism.

    PubMed

    Seo, Mitsunori; Hanada, Atsushi; Kuwahara, Ayuko; Endo, Akira; Okamoto, Masanori; Yamauchi, Yukika; North, Helen; Marion-Poll, Annie; Sun, Tai-Ping; Koshiba, Tomokazu; Kamiya, Yuji; Yamaguchi, Shinjiro; Nambara, Eiji

    2006-11-01

    In a wide range of plant species, seed germination is regulated antagonistically by two plant hormones, abscisic acid (ABA) and gibberellin (GA). In the present study, we have revealed that ABA metabolism (both biosynthesis and inactivation) was phytochrome-regulated in an opposite fashion to GA metabolism during photoreversible seed germination in Arabidopsis. Endogenous ABA levels were decreased by irradiation with a red (R) light pulse in dark-imbibed seeds pre-treated with a far-red (FR) light pulse, and the reduction in ABA levels in response to R light was inhibited in a phytochrome B (PHYB)-deficient mutant. Expression of an ABA biosynthesis gene, AtNCED6, and the inactivation gene, CYP707A2, was regulated in a photoreversible manner, suggesting a key role for the genes in PHYB-mediated regulation of ABA metabolism. Abscisic acid-deficient mutants such as nced6-1, aba2-2 and aao3-4 exhibited an enhanced ability to germinate relative to wild type when imbibed in the dark after irradiation with an FR light pulse. In addition, the ability to synthesize GA was improved in the aba2-2 mutant compared with wild type during dark-imbibition after an FR light pulse. Activation of GA biosynthesis in the aba2-2 mutant was also observed during seed development. These data indicate that ABA is involved in the suppression of GA biosynthesis in both imbibed and developing seeds. Spatial expression patterns of the AtABA2 and AAO3 genes, responsible for last two steps of ABA biosynthesis, were distinct from that of the GA biosynthesis gene, AtGA3ox2, in both imbibed and developing seeds, suggesting that biosynthesis of ABA and GA in seeds occurs in different cell types.

  2. Hormonal control of somatic embryo development from cultured cells of caraway: interactions of abscisic Acid, zeatin, and gibberellic Acid.

    PubMed

    Ammirato, P V

    1977-04-01

    The effects of abscisic acid, zeatin, and gibberellic acid on the development of somatic embryos from cultured cells of caraway (Carum carvi L.) were observed.Somatic embryos complete development on a basal medium without exogenous hormones, but some are subject to developmental abnormalities including malformed cotyledons and accessory embryos. Both zeatin and gibberellic acid, especially in combination, stimulate growth and increase the frequency of aberrant forms. Zeatin causes the formation of multiple shoots, leafy and abnormal cotyledons, and in the dark, enlarged hypocotyls; gibberellic acid effects root elongation, polycotyledony, and some callus formation. In contrast, abscisic acid, at concentrations which do not inhibit embryo maturation, selectively suppresses abnormal proliferations. With abscisic acid, and especially in the dark, a high percentage of embryos complete development with two fleshy cotyledons on unelongated axes free of accessory embryos.In the light, zeatin eliminates abscisic acid inhibition while gibberellic acid only partially counters its effect, promoting elongated radicles and green rather than white cotyledons. In the dark, zeatin in combination with abscisic acid stimulates extensive callusing. Gibberellic acid does not reverse the effects of abscisic acid but rather enhances them and can counter the disruptive effects of zeatin.The results demonstrate that the balance between abscisic acid on the one hand and zeatin and gibberellic acid on the other can effectively control somatic embryo development and either disrupt or ensure normal maturation.

  3. Enzymatic Kolbe-Schmitt reaction to form salicylic acid from phenol: enzymatic characterization and gene identification of a novel enzyme, Trichosporon moniliiforme salicylic acid decarboxylase.

    PubMed

    Kirimura, Kohtaro; Gunji, Hiroaki; Wakayama, Rumiko; Hattori, Takasumi; Ishii, Yoshitaka

    2010-04-02

    Salicylic acid decarboxylase (Sdc) can produce salicylic acid from phenol; it was found in the yeast Trichosporon moniliiforme WU-0401 and was for the first time enzymatically characterized, with the sdc gene heterologously expressed. Sdc catalyzed both reactions: decarboxylation of salicylic acid to phenol and the carboxylation of phenol to form salicylic acid without any byproducts. Both reactions were detected without the addition of any cofactors and occurred even in the presence of oxygen, suggesting that this Sdc is reversible, nonoxidative, and oxygen insensitive. Therefore, it is readily applicable in the selective production of salicylic acid from phenol, the enzymatic Kolbe-Schmitt reaction. The deduced amino acid sequence of the gene, sdc, encoding Sdc comprises 350 amino acid residues corresponding to a 40-kDa protein. The recombinant Escherichia coli BL21(DE3) expressing sdc converted phenol to salicylic acid with a 27% (mol/mol) yield at 30 degrees C for 9h.

  4. Functional analysis of a tomato salicylic acid methyl transferase and its role in synthesis of the flavor volatile methyl salicylate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl salicylate (MeSA) is a volatile plant secondary metabolite that is an important contributor to taste and scent of many fruits and flowers. It is synthesized from salicylic acid (SA), a phytohormone that contributes to plant pathogen defense. MeSA is synthesized by members of a family of O-met...

  5. 40 CFR 721.10089 - Modified salicylic acid, zirconium complex (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified salicylic acid, zirconium... Specific Chemical Substances § 721.10089 Modified salicylic acid, zirconium complex (generic). (a) Chemical... as modified salicylic acid, zirconium complex (PMN P-00-552) is subject to reporting under...

  6. 40 CFR 721.10089 - Modified salicylic acid, zirconium complex (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified salicylic acid, zirconium... Specific Chemical Substances § 721.10089 Modified salicylic acid, zirconium complex (generic). (a) Chemical... as modified salicylic acid, zirconium complex (PMN P-00-552) is subject to reporting under...

  7. 40 CFR 721.10089 - Modified salicylic acid, zirconium complex (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified salicylic acid, zirconium... Specific Chemical Substances § 721.10089 Modified salicylic acid, zirconium complex (generic). (a) Chemical... as modified salicylic acid, zirconium complex (PMN P-00-552) is subject to reporting under...

  8. 40 CFR 721.10089 - Modified salicylic acid, zirconium complex (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Modified salicylic acid, zirconium... Specific Chemical Substances § 721.10089 Modified salicylic acid, zirconium complex (generic). (a) Chemical... as modified salicylic acid, zirconium complex (PMN P-00-552) is subject to reporting under...

  9. 40 CFR 721.10089 - Modified salicylic acid, zirconium complex (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified salicylic acid, zirconium... Specific Chemical Substances § 721.10089 Modified salicylic acid, zirconium complex (generic). (a) Chemical... as modified salicylic acid, zirconium complex (PMN P-00-552) is subject to reporting under...

  10. Effects of Abscisic Acid and of Hydrostatic Pressure Gradient on Water Movement through Excised Sunflower Roots.

    PubMed

    Glinka, Z

    1977-05-01

    The effect of abscisic acid on the exudation rate from decapitated roots of sunflower plants (Helianthus annuus L.) was investigated in the presence and absence of an imposed hydrostatic pressure gradient. The magnitude of the abscisic acid effect was constant even when suctions up to 60 cm Hg were applied to the cut stumps.When roots were bathed in a THO-labeled nutrient solution, the course of the appearance of radioactivity in the exudate, expressed as a function of exudate volume, was not affected by abscisic acid treatment but was strongly speeded up by applying suction.The implications of those findings with regard to the water pathway through the root and the location of the abscisic acid effect are discussed.

  11. Disruption of abscisic acid signaling constitutively activates Arabidopsis resistance to the necrotrophic fungus Plectosphaerella cucumerina.

    PubMed

    Sánchez-Vallet, Andrea; López, Gemma; Ramos, Brisa; Delgado-Cerezo, Magdalena; Riviere, Marie-Pierre; Llorente, Francisco; Fernández, Paula Virginia; Miedes, Eva; Estevez, José Manuel; Grant, Murray; Molina, Antonio

    2012-12-01

    Plant resistance to necrotrophic fungi is regulated by a complex set of signaling pathways that includes those mediated by the hormones salicylic acid (SA), ethylene (ET), jasmonic acid (JA), and abscisic acid (ABA). The role of ABA in plant resistance remains controversial, as positive and negative regulatory functions have been described depending on the plant-pathogen interaction analyzed. Here, we show that ABA signaling negatively regulates Arabidopsis (Arabidopsis thaliana) resistance to the necrotrophic fungus Plectosphaerella cucumerina. Arabidopsis plants impaired in ABA biosynthesis, such as the aba1-6 mutant, or in ABA signaling, like the quadruple pyr/pyl mutant (pyr1pyl1pyl2pyl4), were more resistant to P. cucumerina than wild-type plants. In contrast, the hab1-1abi1-2abi2-2 mutant impaired in three phosphatases that negatively regulate ABA signaling displayed an enhanced susceptibility phenotype to this fungus. Comparative transcriptomic analyses of aba1-6 and wild-type plants revealed that the ABA pathway negatively regulates defense genes, many of which are controlled by the SA, JA, or ET pathway. In line with these data, we found that aba1-6 resistance to P. cucumerina was partially compromised when the SA, JA, or ET pathway was disrupted in this mutant. Additionally, in the aba1-6 plants, some genes encoding cell wall-related proteins were misregulated. Fourier transform infrared spectroscopy and biochemical analyses of cell walls from aba1-6 and wild-type plants revealed significant differences in their Fourier transform infrared spectratypes and uronic acid and cellulose contents. All these data suggest that ABA signaling has a complex function in Arabidopsis basal resistance, negatively regulating SA/JA/ET-mediated resistance to necrotrophic fungi.

  12. Abscisic acid-lipid interactions: a phospholipid monolayer study.

    PubMed

    Bürner, H; Benz, R; Gimmler, H; Hartung, W; Stillwell, W

    1993-08-15

    Lipid monolayer studies were performed on a Langmuir trough in the absence and in the presence of the plant hormone abscisic acid (ABA). The ABA-induced effects on the lipid monolayers can be summarized as follows: (i) ABA as the free acid (pH below 5.3) increased the molecular area and slightly decreased the surface pressure in the collapse points of monolayers made of saturated, unsaturated and of mixed lipids; ABA as the anion showed only minor effects. (ii) The ABA-induced area increase of the lipid monolayers decreased when the surface pressure increased, but some ABA remained in the monolayers made of unsaturated phospholipids even at collapse pressure. (iii) The incorporation of ABA into the monolayers could be inhibited by adding the plant sterol beta-sitosterol to the monolayer forming phospholipids. (iv) There was no substantial difference of ABA action on plant phospholipids as compared with other phospholipids. (v) ABA had a much stronger influence on unsaturated phospholipids than on saturated ones. (vi) ABA decreased the phase-transition temperature of saturated phospholipids. These results, which agree with those obtained from phospholipid vesicle studies, indicate that the physical state of the lipid is important for the ability of ABA penetrating into the lipid monolayer. Finally, a possible relevance of these results is discussed in terms of the action of ABA on guard cell membranes of plants.

  13. Salicylic acid 3-hydroxylase regulates Arabidopsis leaf longevity by mediating salicylic acid catabolism

    PubMed Central

    Zhang, Kewei; Halitschke, Rayko; Yin, Changxi; Liu, Chang-Jun; Gan, Su-Sheng

    2013-01-01

    The plant hormone salicylic acid (SA) plays critical roles in plant defense, stress responses, and senescence. Although SA biosynthesis is well understood, the pathways by which SA is catabolized remain elusive. Here we report the identification and characterization of an SA 3-hydroxylase (S3H) involved in SA catabolism during leaf senescence. S3H is associated with senescence and is inducible by SA and is thus a key part of a negative feedback regulation system of SA levels during senescence. The enzyme converts SA (with a Km of 58.29 µM) to both 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,5-DHBA in vitro but only 2,3-DHBA in vivo. The s3h knockout mutants fail to produce 2,3-DHBA sugar conjugates, accumulate very high levels of SA and its sugar conjugates, and exhibit a precocious senescence phenotype. Conversely, the gain-of-function lines contain high levels of 2,3-DHBA sugar conjugates and extremely low levels of SA and its sugar conjugates and display a significantly extended leaf longevity. This research reveals an elegant SA catabolic mechanism by which plants regulate SA levels by converting it to 2,3-DHBA to prevent SA overaccumulation. The research also provides strong molecular genetic evidence for an important role of SA in regulating the onset and rate of leaf senescence. PMID:23959884

  14. Salicylic acid 3-hydroxylase regulates Arabidopsis leaf longevity by mediating salicylic acid catabolism.

    PubMed

    Zhang, Kewei; Halitschke, Rayko; Yin, Changxi; Liu, Chang-Jun; Gan, Su-Sheng

    2013-09-03

    The plant hormone salicylic acid (SA) plays critical roles in plant defense, stress responses, and senescence. Although SA biosynthesis is well understood, the pathways by which SA is catabolized remain elusive. Here we report the identification and characterization of an SA 3-hydroxylase (S3H) involved in SA catabolism during leaf senescence. S3H is associated with senescence and is inducible by SA and is thus a key part of a negative feedback regulation system of SA levels during senescence. The enzyme converts SA (with a Km of 58.29 µM) to both 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,5-DHBA in vitro but only 2,3-DHBA in vivo. The s3h knockout mutants fail to produce 2,3-DHBA sugar conjugates, accumulate very high levels of SA and its sugar conjugates, and exhibit a precocious senescence phenotype. Conversely, the gain-of-function lines contain high levels of 2,3-DHBA sugar conjugates and extremely low levels of SA and its sugar conjugates and display a significantly extended leaf longevity. This research reveals an elegant SA catabolic mechanism by which plants regulate SA levels by converting it to 2,3-DHBA to prevent SA overaccumulation. The research also provides strong molecular genetic evidence for an important role of SA in regulating the onset and rate of leaf senescence.

  15. The role of cis-carotenoids in abscisic acid biosynthesis.

    PubMed

    Parry, A D; Babiano, M J; Horgan, R

    1990-08-01

    Evidence has been obtained which is consistent with 9'-cis-neoxanthin being a major precursor of abscisic acid (ABA) in higher plants. A mild, rapid procedure was developed for the extraction and analysis of carotenoids from a range of tissues. Once purified the carotenoids were identified from their light-absorbance properties, reactions with dilute acid, high-performance liquid chromatography Rts, mass spectra and the quasiequilibria resulting from iodine-catalysed or chlorophyllsensitised photoisomerisation. Two possible ABA precursors, 9'-cis-neoxanthin and 9-cis-violaxanthin, were identified in extracts of light-grown and etiolated leaves (of Lycopersicon esculentum, Phaseolus vulgaris, Vicia faba, Pisum sativum, Cicer arietinum, Zea mays, Nicotiana plumbaginifolia, Plantago lanceolata and Digitalis purpurea), and roots of light-grown and etiolated plants (Lycopersicon, Phaseolus and Zea). The 9,9'-di-cisisomer of violaxanthin was synthesised but its presence was not detected in any extracts. Levels of 9'-cis-neoxanthin and all-trans-violaxanthin were between 20- to 100-fold greater than those of ABA in light-grown leaves. The levels of 9-cis-violaxanthin were similar to those of ABA but unaffected by water stress. Etiolated Phaseolus leaves contained reduced amounts of carotenoids (15-20% compared with light-grown leaves) but retained the ability to synthesise large amounts of ABA. The amounts of ABA synthesised, measured as increases in ABA and its metabolites phaseic acid and dihydrophaseic acid, were closely matched by decreases in the levels of 9'-cis-neoxanthin and all-trans-violaxanthin. In etiolated seedlings grown on 50% D2O, deuterium incorporation into ABA was similar to that into the xanthophylls. Relative levels of carotenoids in roots and light-grown and etiolated leaves of the ABA-deficient mutants, notabilis, flacca and sitiens were the same as those found in wild-type tomato tissues.

  16. The protective effect of salicylic acid on lysozyme against riboflavin-mediated photooxidation

    NASA Astrophysics Data System (ADS)

    Li, Kun; Wang, Hongbao; Cheng, Lingli; Zhu, Hui; Wang, Mei; Wang, Shi-Long

    2011-06-01

    As a metabolite of aspirin in vivo, salicylic acid was proved to protect lysozyme from riboflavin-mediated photooxidation in this study. The antioxidative properties of salicylic acid were further studied by using time-resolved laser flash photolysis of 355 nm. It can quench the triplet state of riboflavin via electron transfer from salicylic acid to the triplet state of riboflavin with a reaction constant of 2.25 × 10 9 M -1 s -1. Mechanism of antioxidant activities of salicylic acid on lysozyme oxidation was discussed. Salicylic acid can serve as a potential antioxidant to quench the triplet state of riboflavin and reduce oxidative pressure.

  17. Design and Functional Characterization of a Novel Abscisic Acid Analog

    PubMed Central

    Han, Xiaoqiang; Jiang, Lun; Che, Chuanliang; Wan, Chuan; Lu, Huizhe; Xiao, Yumei; Xu, Yanjun; Chen, Zhongzhou; Qin, Zhaohai

    2017-01-01

    The phytohormone abscisic acid (ABA) plays a crucial role in mediating plant growth and development by recruiting genetically redundant ABA receptors. To overcome its oxidation inactivation, we developed a novel ABA analog named 2′,3′-benzo-iso-ABA (iso-PhABA) and studied its function and structural characterization with A. thaliana ABA receptors. The (+)-iso-PhABA form showed much higher ABA-like activities than (+)-ABA including inhibitory effects on the seed germination of lettuce and A. thaliana, wheat embryo germination and rice seedling elongation. The PP2C (protein phosphatases 2C) activity assay showed that (+)-iso-PhABA acted as a potent and selective ABA receptor agonist, which is preferred to PYL10. In some cases, (−)-iso-PhABA showed moderate to high activity for the PYL protein inhibiting PP2C activity, suggesting different mechanisms of action of iso-PhABA and ABA. The complex crystal structure of iso-PhABA with PYL10 was determined and elucidated successfully, revealing that (+)-iso-PhABA was better coordinated in the same binding pocket compared to (+)-ABA. Moreover, the detailed interaction network of iso-PhABA/PYL10 was disclosed and involves hydrogen bonds and multiple hydrophobic interactions that provide a robust framework for the design of novel ABA receptor agonists/antagonists. PMID:28272449

  18. Structural basis and functions of abscisic acid receptors PYLs

    PubMed Central

    Zhang, Xing L.; Jiang, Lun; Xin, Qi; Liu, Yang; Tan, Jian X.; Chen, Zhong Z.

    2015-01-01

    Abscisic acid (ABA) plays a key role in many developmental processes and responses to adaptive stresses in plants. Recently, a new family of nucleocytoplasmic PYR/PYL/RCAR (PYLs) has been identified as bona fide ABA receptors. PYLs together with protein phosphatases type-2C (PP2Cs), Snf1 (Sucrose-non-fermentation 1)-related kinases subfamily 2 (SnRK2s) and downstream substrates constitute the core ABA signaling network. Generally, PP2Cs inactivate SnRK2s kinases by physical interaction and direct dephosphorylation. Upon ABA binding, PYLs change their conformations and then contact and inhibit PP2Cs, thus activating SnRK2s. Here, we reviewed the recent progress in research regarding the structures of the core signaling pathways of ABA, including the (+)-ABA, (−)-ABA and ABA analogs pyrabactin as well as 6AS perception by PYLs, SnRK2s mimicking PYLs in binding PP2Cs. PYLs inhibited PP2Cs in both the presence and absence of ABA and activated SnRK2s. The present review elucidates multiple ABA signal perception and transduction by PYLs, which might shed light on how to design small chemical compounds for improving plant performance in the future. PMID:25745428

  19. Abscisic Acid and Abiotic Stress Tolerance in Crop Plants

    PubMed Central

    Sah, Saroj K.; Reddy, Kambham R.; Li, Jiaxu

    2016-01-01

    Abiotic stress is a primary threat to fulfill the demand of agricultural production to feed the world in coming decades. Plants reduce growth and development process during stress conditions, which ultimately affect the yield. In stress conditions, plants develop various stress mechanism to face the magnitude of stress challenges, although that is not enough to protect them. Therefore, many strategies have been used to produce abiotic stress tolerance crop plants, among them, abscisic acid (ABA) phytohormone engineering could be one of the methods of choice. ABA is an isoprenoid phytohormone, which regulates various physiological processes ranging from stomatal opening to protein storage and provides adaptation to many stresses like drought, salt, and cold stresses. ABA is also called an important messenger that acts as the signaling mediator for regulating the adaptive response of plants to different environmental stress conditions. In this review, we will discuss the role of ABA in response to abiotic stress at the molecular level and ABA signaling. The review also deals with the effect of ABA in respect to gene expression. PMID:27200044

  20. Evolution of Abscisic Acid Synthesis and Signaling Mechanisms

    PubMed Central

    Hauser, Felix; Waadt, Rainer; Schroeder, Julian I.

    2011-01-01

    The plant hormone abscisic acid (ABA) mediates seed dormancy, controls seedling development and triggers tolerance to abiotic stresses, including drought. Core ABA signaling components consist of a recently identified group of ABA receptor proteins of the PYRABACTIN RESISTANCE (PYR)/REGULATORY COMPONENT OF ABA RECEPTOR (RCAR) family that act as negative regulators of members of the PROTEIN PHOSPHATASE 2C (PP2C) family. Inhibition of PP2C activity enables activation of SNF1-RELATED KINASE 2 (SnRK2) protein kinases, which target downstream components, including transcription factors, ion channels and NADPH oxidases. These and other components form a complex ABA signaling network. Here, an in depth analysis of the evolution of components in this ABA signaling network shows that (i) PYR/RCAR ABA receptor and ABF-type transcription factor families arose during land colonization of plants and are not found in algae and other species, (ii) ABA biosynthesis enzymes have evolved to plant- and fungal-specific forms, leading to different ABA synthesis pathways, (iii) existing stress signaling components, including PP2C phosphatases and SnRK kinases, were adapted for novel roles in this plant-specific network to respond to water limitation. In addition, evolutionarily conserved secondary structures in the PYR/RCAR ABA receptor family are visualized. PMID:21549957

  1. Evolution of abscisic acid synthesis and signaling mechanisms.

    PubMed

    Hauser, Felix; Waadt, Rainer; Schroeder, Julian I

    2011-05-10

    The plant hormone abscisic acid (ABA) mediates seed dormancy, controls seedling development and triggers tolerance to abiotic stresses, including drought. Core ABA signaling components consist of a recently identified group of ABA receptor proteins of the PYRABACTIN RESISTANCE (PYR)/REGULATORY COMPONENT OF ABA RECEPTOR (RCAR) family that act as negative regulators of members of the PROTEIN PHOSPHATASE 2C (PP2C) family. Inhibition of PP2C activity enables activation of SNF1-RELATED KINASE 2 (SnRK2) protein kinases, which target downstream components, including transcription factors, ion channels and NADPH oxidases. These and other components form a complex ABA signaling network. Here, an in depth analysis of the evolution of components in this ABA signaling network shows that (i) PYR/RCAR ABA receptor and ABF-type transcription factor families arose during land colonization of plants and are not found in algae and other species, (ii) ABA biosynthesis enzymes have evolved to plant- and fungal-specific forms, leading to different ABA synthesis pathways, (iii) existing stress signaling components, including PP2C phosphatases and SnRK kinases, were adapted for novel roles in this plant-specific network to respond to water limitation. In addition, evolutionarily conserved secondary structures in the PYR/RCAR ABA receptor family are visualized.

  2. Interactions between red light, abscisic acid, and calcium in gravitropism

    NASA Technical Reports Server (NTRS)

    Leopold, A. C.; LaFavre, A. K.

    1989-01-01

    The effect of red light on orthogravitropism of Merit corn (Zea mays L.) roots has been attributed to its effects on the transduction phase of gravitropism (AC Leopold, SH Wettlaufer [1988] Plant Physiol 87:803-805). In an effort to characterize the orthogravitropic transduction system, comparative experiments have been carried out on the effects of red light, calcium, and abscisic acid (ABA). The red light effect can be completely satisfied with added ABA (100 micromolar) or with osmotic shock, which is presumed to increase endogenous ABA. The decay of the red light effect is closely paralleled by the decay of the ABA effect. ABA and exogenous calcium show strong additive effects when applied to either Merit or a line of corn which does not require red light for orthogravitropism. Measurements of the ABA content show marked increases in endogenous ABA in the growing region of the roots after red light. The interpretation is offered that red light or ABA may serve to increase the cytoplasmic concentrations of calcium, and that this may be an integral part of orthogravitropic transduction.

  3. Abscisic acid enhances resistance to Alternaria solani in tomato seedlings.

    PubMed

    Song, Weiwei; Ma, Xinrong; Tan, Hong; Zhou, Jinyan

    2011-07-01

    The plant hormone abscisic acid (ABA) is an important regulator in many aspects of plant growth and development, as well as stress resistance. Here, we investigated the effects of exogenous ABA application on the interaction between tomato (Solanum lycopersicon L.) and Alternaria solani (early blight). Foliar spraying of 7.58 μM ABA was effective in reducing disease severity in tomato plants. Previously, increased activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) were observed in exogenous ABA-treated tomato leaves. Moreover, these enzyme activities were maintained at higher levels in ABA-pretreated and A. solani challenged tomato plants. Tomato defense genes, such as PR1, β-1, 3-glucanase (GLU), PPO, POD, and superoxide dismutase (SOD), were rapidly and significantly up-regulated by exogenous ABA treatment. Furthermore, a subsequent challenge of ABA-pretreated plants with the pathogen A. solani resulted in higher expression of defense genes, compared to water-treated or A. solani inoculated plants. Therefore, our results suggest that exogenous ABA could enhance disease resistance against A. solani infection in tomato through the activation of defense genes and via the enhancement of defense-related enzymatic activities.

  4. Shoot-derived abscisic acid promotes root growth.

    PubMed

    McAdam, Scott A M; Brodribb, Timothy J; Ross, John J

    2016-03-01

    The phytohormone abscisic acid (ABA) plays a major role in regulating root growth. Most work to date has investigated the influence of root-sourced ABA on root growth during water stress. Here, we tested whether foliage-derived ABA could be transported to the roots, and whether this foliage-derived ABA had an influence on root growth under well-watered conditions. Using both application studies of deuterium-labelled ABA and reciprocal grafting between wild-type and ABA-biosynthetic mutant plants, we show that both ABA levels in the roots and root growth in representative angiosperms are controlled by ABA synthesized in the leaves rather than sourced from the roots. Foliage-derived ABA was found to promote root growth relative to shoot growth but to inhibit the development of lateral roots. Increased root auxin (IAA) levels in plants with ABA-deficient scions suggest that foliage-derived ABA inhibits root growth through the root growth-inhibitor IAA. These results highlight the physiological and morphological importance, beyond the control of stomata, of foliage-derived ABA. The use of foliar ABA as a signal for root growth has important implications for regulating root to shoot growth under normal conditions and suggests that leaf rather than root hydration is the main signal for regulating plant responses to moisture.

  5. Abscisic acid controlled sex before transpiration in vascular plants.

    PubMed

    McAdam, Scott A M; Brodribb, Timothy J; Banks, Jo Ann; Hedrich, Rainer; Atallah, Nadia M; Cai, Chao; Geringer, Michael A; Lind, Christof; Nichols, David S; Stachowski, Kye; Geiger, Dietmar; Sussmilch, Frances C

    2016-10-26

    Sexual reproduction in animals and plants shares common elements, including sperm and egg production, but unlike animals, little is known about the regulatory pathways that determine the sex of plants. Here we use mutants and gene silencing in a fern species to identify a core regulatory mechanism in plant sexual differentiation. A key player in fern sex differentiation is the phytohormone abscisic acid (ABA), which regulates the sex ratio of male to hermaphrodite tissues during the reproductive cycle. Our analysis shows that in the fern Ceratopteris richardii, a gene homologous to core ABA transduction genes in flowering plants [SNF1-related kinase2s (SnRK2s)] is primarily responsible for the hormonal control of sex determination. Furthermore, we provide evidence that this ABA-SnRK2 signaling pathway has transitioned from determining the sex of ferns to controlling seed dormancy in the earliest seed plants before being co-opted to control transpiration and CO2 exchange in derived seed plants. By tracing the evolutionary history of this ABA signaling pathway from plant reproduction through to its role in the global regulation of plant-atmosphere gas exchange during the last 450 million years, we highlight the extraordinary effect of the ABA-SnRK2 signaling pathway in plant evolution and vegetation function.

  6. Dissecting Abscisic Acid Signaling Pathways Involved in Cuticle Formation.

    PubMed

    Cui, Fuqiang; Brosché, Mikael; Lehtonen, Mikko T; Amiryousefi, Ali; Xu, Enjun; Punkkinen, Matleena; Valkonen, Jari P T; Fujii, Hiroaki; Overmyer, Kirk

    2016-06-06

    The cuticle is the outer physical barrier of aerial plant surfaces and an important interaction point between plants and the environment. Many environmental stresses affect cuticle formation, yet the regulatory pathways involved remain undefined. We used a genetics and gene expression analysis in Arabidopsis thaliana to define an abscisic acid (ABA) signaling loop that positively regulates cuticle formation via the core ABA signaling pathway, including the PYR/PYL receptors, PP2C phosphatase, and SNF1-Related Protein Kinase (SnRK) 2.2/SnRK2.3/SnRK2.6. Downstream of the SnRK2 kinases, cuticle formation was not regulated by the ABA-responsive element-binding transcription factors but rather by DEWAX, MYB16, MYB94, and MYB96. Additionally, low air humidity increased cuticle formation independent of the core ABA pathway and cell death/reactive oxygen species signaling attenuated expression of cuticle-biosynthesis genes. In Physcomitrella patens, exogenous ABA suppressed expression of cuticle-related genes, whose Arabidopsis orthologs were ABA-induced. Hence, the mechanisms regulating cuticle formation are conserved but sophisticated in land plants. Signaling specifically related to cuticle deficiency was identified to play a major role in the adaptation of ABA signaling pathway mutants to increased humidity and in modulating their immunity to Botrytis cinerea in Arabidopsis. These results define a cuticle-specific downstream branch in the ABA signaling pathway that regulates responses to the external environment.

  7. Abscisic Acid Biosynthesis in Leaves and Roots of Xanthium strumarium.

    PubMed

    Creelman, R A; Gage, D A; Stults, J T; Zeevaart, J A

    1987-11-01

    RESEARCH ON THE BIOSYNTHESIS OF ABSCISIC ACID (ABA) HAS FOCUSED PRIMARILY ON TWO PATHWAYS: (a) the direct pathway from farnesyl pyrophosphate, and (b) the indirect pathway involving a carotenoid precursor. We have investigated which biosynthetic pathway is operating in turgid and stressed Xanthium leaves, and in stressed Xanthium roots using long-term incubations in (18)O(2). It was found that in stressed leaves three atoms of (18)O from (18)O(2) are incorporated into the ABA molecule, and that the amount of (18)O incorporated increases with time. One (18)O atom is incorporated rapidly into the carboxyl group of ABA, whereas the other two atoms are very slowly incorporated into the ring oxygens. The fourth oxygen atom in the carboxyl group of ABA is derived from water. ABA from stressed roots of Xanthium incubated in (18)O(2) shows a labeling pattern similar to that of ABA in stressed leaves, but with incorporation of more (18)O into the tertiary hydroxyl group at C-1' after 6 and 12 hours than found in ABA from stressed leaves. It is proposed that the precursors to stress-induced ABA are xanthophylls, and that a xanthophyll lacking an oxygen function at C-6 (carotenoid numbering scheme) plays a crucial role in ABA biosynthesis in Xanthium roots. In turgid Xanthium leaves, (18)O is incorporated into ABA to a much lesser extent than it is in stressed leaves, whereas exogenously applied (14)C-ABA is completely catabolized within 48 hours. This suggests that ABA in turgid leaves is either (a) made via a biosynthetic pathway which is different from the one in stressed leaves, or (b) has a half-life on the order of days as compared with a half-life of 15.5 hours in water-stressed Xanthium leaves. Phaseic acid showed a labeling pattern similar to that of ABA, but with an additional (18)O incorporated during 8'-hydroxylation of ABA to phaseic acid.

  8. 1-Acetylpyrene-salicylic acid: photoresponsive fluorescent organic nanoparticles for the regulated release of a natural antimicrobial compound, salicylic acid.

    PubMed

    Barman, Shrabani; Mukhopadhyay, Sourav K; Behara, Krishna Kalyani; Dey, Satyahari; Singh, N D Pradeep

    2014-05-28

    Photoresponsive 1-acetylpyrene-salicylic acid (AcPy-SA) nanoparticles (NPs) were developed for the regulated release of a natural antimicrobial compound, salicylic acid. The strong fluorescent properties of AcPy-SA NPs have been extensively used for potential in vitro cell imaging. The phototrigger capability of our newly prepared AcPy-SA NPs was utilized for the efficient release of an antimicrobial compound, salicylic acid. The photoregulated drug release of AcPy-SA NPs has been shown by the subsequent switching off and on of a visible-light source. In vitro biological studies reveal that AcPy-SA NPs of ∼68 nm size deliver the antimicrobial drug salicylic acid into the bacteria cells (Pseudomonas aeruginosa) and efficiently kill the cells upon exposure to visible light (≥410 nm). Such photoresponsive fluorescent organic NPs will be highly beneficial for targeted and regulated antimicrobial drug release because of their biocompatible nature, efficient cellular uptake, and light-induced drug release ability.

  9. Salicylic acid induces apoptosis in colon carcinoma cells grown in-vitro: Influence of oxygen and salicylic acid concentration

    SciTech Connect

    Zitta, Karina; Meybohm, Patrick; Bein, Berthold; Huang, Ying; Heinrich, Christin; Scholz, Jens; Steinfath, Markus; Albrecht, Martin

    2012-04-15

    In solid tumors the hypoxic environment can promote tumor progression and resistance to therapy. Recently, acetylsalicylic acid a major component of analgesic drugs and its metabolite salicylic acid (SA) have been shown to reduce the risk of colon cancer, but the mechanisms of action remain still unclear. Here we elucidate the effects of physiologically relevant concentrations of SA on colon carcinoma cells (CaCo-2) grown under normoxic and hypoxic conditions. Western blotting, caspase-3/7 apoptosis assays, MTS cell-proliferation assays, LDH cytotoxicity assays and hydrogen peroxide measurements were performed to investigate the effects of 1 and 10 {mu}M SA on CaCo-2 cells grown under normoxic conditions and cells exposed to hypoxia. Under normoxic conditions, SA did not influence cell proliferation or LDH release of CaCo-2 cells. However, caspase-3/7 activity was significantly increased. Under hypoxia, cell proliferation was reduced and LDH release and caspase-3/7 activities were increased. None of these parameters was altered by the addition of SA under hypoxic conditions. Hypoxia increased hydrogen peroxide concentrations 300-fold and SA significantly augmented the release of hydrogen peroxide under normoxic, but not under hypoxic conditions. Phosphorylation of the pro-survival kinases akt and erk1/2 was not changed by SA under hypoxic conditions, whereas under normoxia SA reduced phosphorylation of erk1/2 after 2 hours. We conclude that in colon carcinoma cells effects of SA on apoptosis and cellular signaling are dependent on the availability of oxygen. -- Highlights: Black-Right-Pointing-Pointer Effects of salicylic acid on colon carcinoma cells grown under normoxic and hypoxic conditions Black-Right-Pointing-Pointer Salicylic acid increases caspase-3/7 activity and hydrogen peroxide release under normoxia Black-Right-Pointing-Pointer Salicylic acid decreases pro-survival erk-1/2 phosphorylation under normoxia Black-Right-Pointing-Pointer Salicylic acid does

  10. Effects of mechanical stress or abscisic acid on growth, water status and leaf abscisic acid content of eggplant seedlings

    NASA Technical Reports Server (NTRS)

    Latimer, J. G.; Mitchell, C. A.

    1988-01-01

    Container-grown eggplant (Solanum melongena L. var esculentum Nees. 'Burpee's Black Beauty') seedlings were conditioned with brief, periodic mechanical stress or abscisic acid (ABA) in a greenhouse prior to outdoor exposure. Mechanical stress consisted of seismic (shaking) or thigmic (stem flexing) treatment. Exogenous ABA (10(-3) or 10(-4)M) was applied as a soil drench 3 days prior to outdoor transfer. During conditioning, only thigmic stress reduced stem elongation and only 10(-3) M ABA reduced relative growth rate (RGR). Both conditioning treatments increased leaf specific chlorophyll content, but mechanical stress did not affect leaf ABA content. Outdoor exposure of unconditioned eggplant seedlings decreased RGR and leaf-specific chlorophyll content, but tended to increase leaf ABA content relative to that of plants maintained in the greenhouse. Conditioning did not affect RGR of plants subsequently transferred outdoors, but did reduce stem growth. Seismic stress applied in the greenhouse reduced dry weight gain by plants subsequently transferred outdoors. Mechanical stress treatments increased leaf water potential by 18-25% relative to that of untreated plants.

  11. Overexpression of Poplar Pyrabactin Resistance-Like Abscisic Acid Receptors Promotes Abscisic Acid Sensitivity and Drought Resistance in Transgenic Arabidopsis.

    PubMed

    Yu, Jingling; Yang, Lei; Liu, Xiaobing; Tang, Renjie; Wang, Yuan; Ge, Haiman; Wu, Mengting; Zhang, Jiang; Zhao, Fugeng; Luan, Sheng; Lan, Wenzhi

    2016-01-01

    Drought stress is an important environmental factor limiting productivity of plants, especially fast growing species with high water consumption like poplar. Abscisic acid (ABA) is a phytohormone that positively regulates seed dormancy and drought resistance. The PYR1 (Pyrabactin Resistance 1)/ PYRL (PYR-Like)/ RCAR (Regulatory Component of ABA Receptor) (PYR/PYL/RCAR) ABA receptor family has been identified and widely characterized in Arabidopsis thaliana. However, their functions in poplars remain unknown. Here, we report that 2 of 14 PYR/PYL/RCAR orthologues in poplar (Populus trichocarpa) (PtPYRLs) function as a positive regulator of the ABA signal transduction pathway. The Arabidopsis transient expression and yeast two-hybrid assays showed the interaction among PtPYRL1 and PtPYRL5, a clade A protein phosphatase 2C, and a SnRK2, suggesting that a core signalling complex for ABA signaling pathway exists in poplars. Phenotypic analysis of PtPYRL1 and PtPYRL5 transgenic Arabidopsis showed that these two genes positively regulated the ABA responses during the seed germination. More importantly, the overexpression of PtPYRL1 and PtPYRL5 substantially improved ABA sensitivity and drought stress tolerance in transgenic plants. In summary, we comprehensively uncovered the properties of PtPYRL1 and PtPYRL5, which might be good target genes to genetically engineer drought-Resistant plants.

  12. Overexpression of Poplar Pyrabactin Resistance-Like Abscisic Acid Receptors Promotes Abscisic Acid Sensitivity and Drought Resistance in Transgenic Arabidopsis

    PubMed Central

    Liu, Xiaobing; Tang, Renjie; Wang, Yuan; Ge, Haiman; Wu, Mengting; Zhang, Jiang; Zhao, Fugeng; Luan, Sheng; Lan, Wenzhi

    2016-01-01

    Drought stress is an important environmental factor limiting productivity of plants, especially fast growing species with high water consumption like poplar. Abscisic acid (ABA) is a phytohormone that positively regulates seed dormancy and drought resistance. The PYR1 (Pyrabactin Resistance 1)/ PYRL (PYR-Like)/ RCAR (Regulatory Component of ABA Receptor) (PYR/PYL/RCAR) ABA receptor family has been identified and widely characterized in Arabidopsis thaliana. However, their functions in poplars remain unknown. Here, we report that 2 of 14 PYR/PYL/RCAR orthologues in poplar (Populus trichocarpa) (PtPYRLs) function as a positive regulator of the ABA signal transduction pathway. The Arabidopsis transient expression and yeast two-hybrid assays showed the interaction among PtPYRL1 and PtPYRL5, a clade A protein phosphatase 2C, and a SnRK2, suggesting that a core signalling complex for ABA signaling pathway exists in poplars. Phenotypic analysis of PtPYRL1 and PtPYRL5 transgenic Arabidopsis showed that these two genes positively regulated the ABA responses during the seed germination. More importantly, the overexpression of PtPYRL1 and PtPYRL5 substantially improved ABA sensitivity and drought stress tolerance in transgenic plants. In summary, we comprehensively uncovered the properties of PtPYRL1 and PtPYRL5, which might be good target genes to genetically engineer drought-Resistant plants. PMID:27992471

  13. Up-regulation of abscisic acid signaling pathway facilitates aphid xylem absorption and osmoregulation under drought stress

    PubMed Central

    Guo, Huijuan; Sun, Yucheng; Peng, Xinhong; Wang, Qinyang; Harris, Marvin; Ge, Feng

    2016-01-01

    The activation of the abscisic acid (ABA) signaling pathway reduces water loss from plants challenged by drought stress. The effect of drought-induced ABA signaling on the defense and nutrition allocation of plants is largely unknown. We postulated that these changes can affect herbivorous insects. We studied the effects of drought on different feeding stages of pea aphids in the wild-type A17 of Medicago truncatula and ABA signaling pathway mutant sta-1. We examined the impact of drought on plant water status, induced plant defense signaling via the abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA) pathways, and on the host nutritional quality in terms of leaf free amino acid content. During the penetration phase of aphid feeding, drought decreased epidermis/mesophyll resistance but increased mesophyll/phloem resistance of A17 but not sta-1 plants. Quantification of transcripts associated with ABA, JA and SA signaling indicated that the drought-induced up-regulation of ABA signaling decreased the SA-dependent defense but increased the JA-dependent defense in A17 plants. During the phloem-feeding phase, drought had little effect on the amino acid concentrations and the associated aphid phloem-feeding parameters in both plant genotypes. In the xylem absorption stage, drought decreased xylem absorption time of aphids in both genotypes because of decreased water potential. Nevertheless, the activation of the ABA signaling pathway increased water-use efficiency of A17 plants by decreasing the stomatal aperture and transpiration rate. In contrast, the water potential of sta-1 plants (unable to close stomata) was too low to support xylem absorption activity of aphids; the aphids on sta-1 plants had the highest hemolymph osmolarity and lowest abundance under drought conditions. Taken together this study illustrates the significance of cross-talk between biotic-abiotic signaling pathways in plant-aphid interaction, and reveals the mechanisms leading to alter

  14. Up-regulation of abscisic acid signaling pathway facilitates aphid xylem absorption and osmoregulation under drought stress.

    PubMed

    Guo, Huijuan; Sun, Yucheng; Peng, Xinhong; Wang, Qinyang; Harris, Marvin; Ge, Feng

    2016-02-01

    The activation of the abscisic acid (ABA) signaling pathway reduces water loss from plants challenged by drought stress. The effect of drought-induced ABA signaling on the defense and nutrition allocation of plants is largely unknown. We postulated that these changes can affect herbivorous insects. We studied the effects of drought on different feeding stages of pea aphids in the wild-type A17 of Medicago truncatula and ABA signaling pathway mutant sta-1. We examined the impact of drought on plant water status, induced plant defense signaling via the abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA) pathways, and on the host nutritional quality in terms of leaf free amino acid content. During the penetration phase of aphid feeding, drought decreased epidermis/mesophyll resistance but increased mesophyll/phloem resistance of A17 but not sta-1 plants. Quantification of transcripts associated with ABA, JA and SA signaling indicated that the drought-induced up-regulation of ABA signaling decreased the SA-dependent defense but increased the JA-dependent defense in A17 plants. During the phloem-feeding phase, drought had little effect on the amino acid concentrations and the associated aphid phloem-feeding parameters in both plant genotypes. In the xylem absorption stage, drought decreased xylem absorption time of aphids in both genotypes because of decreased water potential. Nevertheless, the activation of the ABA signaling pathway increased water-use efficiency of A17 plants by decreasing the stomatal aperture and transpiration rate. In contrast, the water potential of sta-1 plants (unable to close stomata) was too low to support xylem absorption activity of aphids; the aphids on sta-1 plants had the highest hemolymph osmolarity and lowest abundance under drought conditions. Taken together this study illustrates the significance of cross-talk between biotic-abiotic signaling pathways in plant-aphid interaction, and reveals the mechanisms leading to alter

  15. Abscisic acid and sucrose regulate tomato and strawberry fruit ripening through the abscisic acid-stress-ripening transcription factor.

    PubMed

    Jia, Haifeng; Jiu, Songtao; Zhang, Cheng; Wang, Chen; Tariq, Pervaiz; Liu, Zhongjie; Wang, Baoju; Cui, Liwen; Fang, Jinggui

    2016-10-01

    Although great progress has been made towards understanding the role of abscisic acid (ABA) and sucrose in fruit ripening, the mechanisms underlying the ABA and sucrose signalling pathways remain elusive. In this study, transcription factor ABA-stress-ripening (ASR), which is involved in the transduction of ABA and sucrose signalling pathways, was isolated and analysed in the nonclimacteric fruit, strawberry and the climacteric fruit, tomato. We have identified four ASR isoforms in tomato and one in strawberry. All ASR sequences contained the ABA stress- and ripening-induced proteins and water-deficit stress-induced proteins (ABA/WDS) domain and all ASR transcripts showed increased expression during fruit development. The expression of the ASR gene was influenced not only by sucrose and ABA, but also by jasmonic acid (JA) and indole-3-acetic acid (IAA), and these four factors were correlated with each other during fruit development. ASR bound the hexose transporter (HT) promoter, which contained a sugar box that activated downstream gene expression. Overexpression of the ASR gene promoted fruit softening and ripening, whereas RNA interference delayed fruit ripening, as well as affected fruit physiological changes. Change in ASR gene expression influenced the expression of several ripening-related genes such as CHS, CHI, F3H, DFR, ANS, UFGT, PG, PL, EXP1/2, XET16, Cel1/2 and PME. Taken together, this study may provide new evidence on the important role of ASR in cross-signalling between ABA and sucrose to regulate tomato and strawberry fruit ripening. The findings of this study also provide new insights into the regulatory mechanism underlying fruit development.

  16. Leveraging abscisic acid receptors for efficient water use in Arabidopsis

    PubMed Central

    Yang, Zhenyu; Liu, Jinghui; Tischer, Stefanie V.; Christmann, Alexander; Windisch, Wilhelm; Schnyder, Hans; Grill, Erwin

    2016-01-01

    Plant growth requires the influx of atmospheric CO2 through stomatal pores, and this carbon uptake for photosynthesis is inherently associated with a large efflux of water vapor. Under water deficit, plants reduce transpiration and are able to improve carbon for water exchange leading to higher water use efficiency (WUE). Whether increased WUE can be achieved without trade-offs in plant growth is debated. The signals mediating the WUE response under water deficit are not fully elucidated but involve the phytohormone abscisic acid (ABA). ABA is perceived by a family of related receptors known to mediate acclimation responses and to reduce transpiration. We now show that enhanced stimulation of ABA signaling via distinct ABA receptors can result in plants constitutively growing at high WUE in the model species Arabidopsis. WUE was assessed by three independent approaches involving gravimetric analyses, 13C discrimination studies of shoots and derived cellulose fractions, and by gas exchange measurements of whole plants and individual leaves. Plants expressing the ABA receptors RCAR6/PYL12 combined up to 40% increased WUE with high growth rates, i.e., are water productive. Water productivity was associated with maintenance of net carbon assimilation by compensatory increases of leaf CO2 gradients, thereby sustaining biomass acquisition. Leaf surface temperatures and growth potentials of plants growing under well-watered conditions were found to be reliable indicators for water productivity. The study shows that ABA receptors can be explored to generate more plant biomass per water transpired, which is a prime goal for a more sustainable water use in agriculture. PMID:27247417

  17. Formulation of salicylate-based poly(anhydride-ester) microspheres for short- and long-term salicylic acid delivery

    PubMed Central

    Rosario-Meléndez, Roselin; Ouimet, Michelle A.; Uhrich, Kathryn E.

    2013-01-01

    The formulation of salicylate-based poly(anhydride-ester) (PAE) microspheres was optimized by altering polymer concentration and homogenization speed to improve the overall morphology. The microspheres were prepared using three salicylate-based PAEs with different chemical compositions comprised of either a heteroatomic, linear aliphatic, or branched aliphatic moiety. These PAEs broadened the range of complete salicylic acid release to now include days, weeks and months. The molecular weight (Mw), polydispersity index (PDI) and glass transition temperature (Tg) of the formulated polymers were compared to the unformulated polymers. In general, the Mw and PDI exhibited decreased and increased values, respectively, after formulation, whereas the Tg changes did not follow a specific trend. Microsphere size and morphology were determined using scanning electron microscopy. These microspheres exhibited smooth surfaces, no aggregation, and size distributions ranging from 2-34 m in diameter. In vitro release studies of the chemically incorporated salicylic acid displayed widely tunable release profiles. PMID:23420391

  18. Cross-linked, biodegradable, cytocompatible salicylic acid based polyesters for localized, sustained delivery of salicylic acid: an in vitro study.

    PubMed

    Chandorkar, Yashoda; Bhagat, Rajesh K; Madras, Giridhar; Basu, Bikramjit

    2014-03-10

    In order to suppress chronic inflammation while supporting cell proliferation, there has been a continuous surge toward development of polymers with the intention of delivering anti-inflammatory molecules in a sustained manner. In the above backdrop, we report the synthesis of a novel, stable, cross-linked polyester with salicylic acid (SA) incorporated in the polymeric backbone and propose a simple synthesis route by melt condensation. The as-synthesized polymer was hydrophobic with a glass transition temperature of 1 °C, which increases to 17 °C upon curing. The combination of NMR and FT-IR spectral techniques established the ester linkages in the as-synthesized SA-based polyester. The pH-dependent degradation rate and the rate of release of salicylic acid from the as-synthesized SA-based polymer were studied at physiological conditions in vitro. The polyester underwent surface erosion and exhibited linear degradation kinetics in which a change in degradation rate is observed after 4-10 days and 24% mass loss was recorded after 4 months at 37 °C and pH 7.4. The delivery of salicylic acid also showed a similar change in slopes, with a sustained release rate of 3.5% in 4 months. The cytocompatibility studies of these polyesters were carried out with C2C12 murine myoblast cells using techniques like MTT assay and flow cytometry. Our results strongly suggest that SA-based polyester supports cell proliferation for 3 days in culture and do not cause cell death (<7%), as quantified by propidium iodide (PI) stained cells. Hence, these polyesters can be used as implant materials for localized, sustained delivery of salicylic acid and have applications in adjuvant cancer therapy, chronic wound healing, and as an alternative to commercially available polymers like poly(lactic acid) and poly(glycolic acid) or their copolymers.

  19. Boron removal from aqueous solutions by activated carbon impregnated with salicylic acid.

    PubMed

    Celik, Z Ceylan; Can, B Z; Kocakerim, M Muhtar

    2008-03-21

    In this study, the removal of boric acid from aqueous solution by activated carbon impregnated with salicylic acid was studied in batch system. pH, adsorbent amount, initial boron concentration, temperature, shaking rate and salicylic acid film thickness were chosen as parameters. Boron removal efficiencies increased with increasing adsorbent amount, temperature and pH, decreasing initial boron concentration. As thickness of salicylic acid film on activated carbon becomes thin up to 0.088nm, the efficiency increased, and then, the efficiency decreased with becoming thinner than 0.088nm of salicylic acid film. Shaking rate was no effect on removal efficiency. In result, it was determined that the use of salicylic acid as an impregnant for activated carbon led to the increase of the amount of boron adsorbed. A lactone ring, being the most appropriate conformation, forms between boric acid and -COOH and -OH groups of salicylic acid.

  20. Simultaneous determination of salicylic acid and salicylamide in biological fluids

    NASA Astrophysics Data System (ADS)

    Murillo Pulgarín, J. A.; Alañón Molina, A.; Sánchez-Ferrer Robles, I.

    2011-09-01

    A new methodology for the simultaneous determination of salicylic acid and salicylamide in biological fluids is proposed. The strong overlapping of the fluorescence spectra of both analytes makes impossible the conventional fluorimetric determination. For that reason, the use of fluorescence decay curves to resolve mixtures of analytes is proposed; this is a novel technique that provides the benefits in selectivity and sensitivity of the fluorescence decay curves. In order to assess the goodness of the proposed method, a prediction set of synthetic samples were analyzed obtaining recuperation percentages between 98.2 and 104.6%. Finally, a study of the detection limits was done using a new criterion resulting in values for the detection limits of 8.2 and 11.6 μg L -1 for salicylic acid and salicylamide respectively. The validity of the method was tested in human serum and human urine spiked with aliquots of the analytes. Recoveries obtained were 96.2 and 94.5% for salicylic acid and salicylamide respectively.

  1. Endogenous Levels of Abscisic Acid and Decanoic Acid in Dutch Iris Bulbs and the Influence of Abscisic Acid and Decanoic Acid on Iris Meristems Cultured In Vitro1

    PubMed Central

    Doss, Robert P.; Kimura, Yosh; Christian, James K.

    1983-01-01

    Abscisic acid (ABA) and decanoic acid inhibited shoot elongation and floral development of Dutch iris (Iris hollandica Hoog. cv Ideal) meristems cultured in vitro. No synergism with respect to inhibition of leaf growth between ABA and decanoic acid was observed. With monthly harvest dates, from July 10, 1981 to October 10, 1981, there was a progressive decrease in endogenous level of free ABA in `Ideal' iris bulbs. Bulbs subjected to a full set of the usual preplanting storage conditions flowered, on average, 46 days after planting versus 194 days after planting for bulbs planted directly after harvest. ABA levels at harvest were 4- to 5-fold those after the preplanting storage treatment. In general, ABA levels did not correlate well with the length of time from planting until flowering of iris bulbs. Endogenous decanoic acid levels did not follow any pattern with respect to harvest date or postharvest treatment. After the postharvest high temperature treatment, there was about a 3-fold increase in nonscale decanoic acid concentration. Decanoic acid levels, in nonscale tissue, remained high after each of the other postharvest treatments. It is concluded that there is no good evidence to support the contention that either ABA or decanoic acid is directly involved in iris bulb dormancy. PMID:16663072

  2. Radiation chemistry of salicylic and methyl substituted salicylic acids: Models for the radiation chemistry of pharmaceutical compounds

    NASA Astrophysics Data System (ADS)

    Ayatollahi, Shakiba; Kalnina, Daina; Song, Weihua; Turks, Maris; Cooper, William J.

    2013-11-01

    Salicylic acid and its derivatives are components of many medications and moieties found in numerous pharmaceutical compounds. They have been used as models for various pharmaceutical compounds in pharmacological studies, for the treatment of pharmaceuticals and personal care products (PPCPs), and, reactions with natural organic matter (NOM). In this study, the radiation chemistry of benzoic acid, salicylic acid and four methyl substituted salicylic acids (MSA) is reported. The absolute bimolecular reaction rate constants for hydroxyl radical reaction with benzoic and salicylic acids as well as 3-methyl-, 4-methyl-, 5-methyl-, and 6-methyl-salicylic acid were determined (5.86±0.54)×109, (1.07±0.07)×1010, (7.48±0.17)×109, (7.31±0.29)×109, (5.47±0.25)×109, (6.94±0.10)×109 (M-1 s-1), respectively. The hydrated electron reaction rate constants were measured (3.02±0.10)×109, (8.98±0.27)×109, (5.39±0.21)×109, (4.33±0.17)×109, (4.72±0.15)×109, (1.42±0.02)×109 (M-1 s-1), respectively. The transient absorption spectra for the six model compounds were examined and their role as model compounds for the radiation chemistry of pharmaceuticals investigated.

  3. Salicylic Acid, a Plant Defense Hormone, Is Specifically Secreted by a Molluscan Herbivore

    PubMed Central

    Kästner, Julia; von Knorre, Dietrich; Himanshu, Himanshu; Erb, Matthias; Baldwin, Ian T.; Meldau, Stefan

    2014-01-01

    Slugs and snails are important herbivores in many ecosystems. They differ from other herbivores by their characteristic mucus trail. As the mucus is secreted at the interface between the plants and the herbivores, its chemical composition may play an essential role in plant responses to slug and snail attack. Based on our current knowledge about host-manipulation strategies employed by pathogens and insects, we hypothesized that mollusks may excrete phytohormone-like substances into their mucus. We therefore screened locomotion mucus from thirteen molluscan herbivores for the presence of the plant defense hormones jasmonic acid (JA), salicylic acid (SA) and abscisic acid (ABA). We found that the locomotion mucus of one slug, Deroceras reticulatum, contained significant amounts of SA, a plant hormone that is known to induce resistance to pathogens and to suppress plant immunity against herbivores. None of the other slugs and snails contained SA or any other hormone in their locomotion mucus. When the mucus of D. reticulatum was applied to wounded leaves of A. thaliana, the promotor of the SA-responsive gene pathogenesis related 1 (PR1) was activated, demonstrating the potential of the mucus to regulate plant defenses. We discuss the potential ecological, agricultural and medical implications of this finding. PMID:24466122

  4. Abscisic Acid and Ethylene Increase in Heterodera avenae-infected Tolerant or Intolerant Oat Cultivars

    PubMed Central

    Volkmar, K. M.

    1991-01-01

    The relationship between root stunting caused by the cereal cyst nematode and levels of two root growth inhibiting hormones, abscisic acid and ethylene, was investigated in aseptically cultured root segments and in intact roots of two oat cultivars differing in tolerance to the nematode. Cultured root segments of oat cultivars New Zealand Cape (tolerant) and Sual (intolerant) were inoculated with sterilized Heterodera avenae second-stage juveniles. Suppressed growth of root axes and emerged laterals following nematode penetration corresponded to an increase in abscisic acid and ethylene in roots of both intolerant and tolerant cultivars. When the experiment was repeated on intact root systems, nematodes retarded root growth of Sual more than New Zealand Cape despite an increase in ABA and ethylene in both cultivars. Abscisic acid and (or) ethylene may be involved in growth inhibition of H. avenae-infected roots but appear to play no direct role in determining tolerance. PMID:19283149

  5. Synthetic nanoparticles of bovine serum albumin with entrapped salicylic acid

    PubMed Central

    Bronze-Uhle, ES; Costa, BC; Ximenes, VF; Lisboa-Filho, PN

    2017-01-01

    Bovine serum albumin (BSA) is highly water soluble and binds drugs or inorganic substances noncovalently for their effective delivery to various affected areas of the body. Due to the well-defined structure of the protein, containing charged amino acids, albumin nanoparticles (NPs) may allow electrostatic adsorption of negatively or positively charged molecules, such that substantial amounts of drug can be incorporated within the particle, due to different albumin-binding sites. During the synthesis procedure, pH changes significantly. This variation modifies the net charge on the surface of the protein, varying the size and behavior of NPs as the drug delivery system. In this study, the synthesis of BSA NPs, by a desolvation process, was studied with salicylic acid (SA) as the active agent. SA and salicylates are components of various plants and have been used for medication with anti-inflammatory, antibacterial, and antifungal properties. However, when administered orally to adults (usual dose provided by the manufacturer), there is 50% decomposition of salicylates. Thus, there has been a search for some time to develop new systems to improve the bioavailability of SA and salicylates in the human body. Taking this into account, during synthesis, the pH was varied (5.4, 7.4, and 9) to evaluate its influence on the size and release of SA of the formed NPs. The samples were analyzed using field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, zeta potential, and dynamic light scattering. Through fluorescence, it was possible to analyze the release of SA in vitro in phosphate-buffered saline solution. The results of chemical morphology characterization and in vitro release studies indicated the potential use of these NPs as drug carriers in biological systems requiring a fast release of SA. PMID:28096662

  6. Water Deficit-Induced Changes in Abscisic Acid, Growth, Polysomes, and Translatable RNA in Soybean Hypocotyls

    PubMed Central

    Bensen, Robert J.; Boyer, John S.; Mullet, John E.

    1988-01-01

    Soybean seedlings (Glycine max L.) were germinated and dark-grown in water-saturated vermiculite (water potential = −0.01 megapascal) for 48 hours, then transferred either to water-saturated vermiculite or to low water potential vermiculite (water potential = −0.30 megapascal). A decrease in growth rate was detectable within 0.8 hour post-transfer to low water potential vermiculite. A fourfold increase in the abscisic acid content of the elongating region was observed within 0.5 hour. At 24 hours post-transfer, hypocotyl elongation was severely arrested and abscisic acid reached its highest measured level: 3.7 nanograms per milligram dry weight (74-fold increase). A comparison of the polyA+ RNA populations isolated at 24 hours post-transfer from the elongating region of water-saturated and low water potential vermiculite-grown seedlings was made by two-dimensional (isoelectric focusing-sodium dodecyl sulfate) polyacrylamide gel analysis of in vitro translation products. It revealed both increases and decreases in the relative amounts of a number of translation products. Rewatering seedlings grown in low water potential vermiculite at 24 hours post-transfer led to a total recovery in growth rate within 0.5 hour, while abscisic acid in the elongating hypocotyl region required 1 to 2 hours to return to uninduced levels. Application of 1.0 millimolar (±) abscisic acid to well-watered seedlings resulted in a 48% reduction in hypocotyl growth rate during the first 2 hours after treatment. Plants treated with abscisic acid for 24 hours had a lower polysome content than control plants. However, hypocotyl growth inhibition in abscisic acid-treated seedlings preceded the decline in polysome content. Images Fig. 4 PMID:16666297

  7. Salicylic acid-induced resistance to Fusarium oxysporum f. sp. lycopersici in tomato.

    PubMed

    Mandal, Sudhamoy; Mallick, Nirupama; Mitra, Adinpunya

    2009-07-01

    We demonstrated that exogenous application of 200 microM salicylic acid through root feeding and foliar spray could induce resistance against Fusarium oxysporum f. sp. Lycopersici (Fol) in tomato. Endogenous accumulation of free salicylic acid in tomato roots was detected by HPLC and identification was confirmed by LC-MS/MS analysis. At 168h of salicylic acid treatment through roots, the endogenous salicylic acid level in the roots increased to 1477ngg(-1) FW which was 10 times higher than control plants. Similarly, the salicylic acid content was 1001ngg(-1) FW at 168h of treatment by foliar spray, which was 8.7 times higher than control plants. The activities of phenylalanine ammonia lyase (PAL, EC 4.3.1.5) and peroxidase (POD, EC 1.11.1.7) were 5.9 and 4.7 times higher, respectively than the control plants at 168h of salicylic acid feeding through the roots. The increase in PAL and POD activities was 3.7 and 3.3 times higher, respectively at 168h of salicylic acid treatments through foliar spray than control plants. The salicylic acid-treated tomato plants challenged with Fol exhibited significantly reduced vascular browning and leaf yellowing wilting. The mycelial growth of Fol was not significantly affected by salicylic acid. Significant increase in basal level of salicylic acid in noninoculated plants indicated that tomato root system might have the capacity to assimilate and distribute salicylic acid throughout the plant. The results indicated that the induced resistance observed in tomato against Fol might be a case of salicylic acid-dependent systemic acquired resistance.

  8. Pericarp browning and quality management of litchi fruit by antioxidants and salicylic acid during ambient storage.

    PubMed

    Kumar, Deepak; Mishra, Daya Shankar; Chakraborty, Binayak; Kumar, Prabhat

    2013-08-01

    Different antioxidants and salicylic acid were tested to overcome pericarp browning and to maintain the postharvest quality of the litchi fruits at ambient storage. It was found that 0.5% salicylic acid, 1% isoascorbic acid and 1% N-acetyl cysteine performed better over sulphur dioxide (SO2) fumigation for most of the parameters under study. Application of 0.5% salicylic acid found superior to reduce the pericarp browning, relative leakage rate, and decay percentage. It was effective in reduction of polyphenol oxidase activity and improvement of anthocyanin pigments of the fruit pericarp over other treatments. Total soluble solid, titratable acidity and ascorbic acid of the litchi fruits were recorded highest with the application of 1% isoascorbic acid followed by 0.5% salicylic acid treatment. Therefore, 0.5% salicylic acid and 1% isoascorbic could be used as an alternative of SO2 fumigation for quality retention of litchi fruits.

  9. P-HYDROXYPHENYLPYRUVATE DIOXYGENASE from Medicago sativa is involved in vitamin E biosynthesis and abscisic acid-mediated seed germination

    PubMed Central

    Jiang, Jishan; Chen, Zhihong; Ban, Liping; Wu, Yudi; Huang, Jianping; Chu, Jinfang; Fang, Shuang; Wang, Zan; Gao, Hongwen; Wang, Xuemin

    2017-01-01

    P-HYDROXYPHENYLPYRUVATE DIOXYGENASE (HPPD) is the first committed enzyme involved in the biosynthesis of vitamin E, and is characterized by catalyzing the conversion of p-hydroxyphenyl pyruvate (HPP) to homogentisic acid (HGA). Here, an HPPD gene was cloned from Medicago sativa L. and designated MsHPPD, which was expressed at high levels in alfalfa leaves. PEG 6000 (polyethylene glycol), NaCl, abscisic acid and salicylic acid were shown to significantly induce MsHPPD expression, especially in the cotyledons and root tissues. Overexpression of MsHPPD was found to significantly increase the level of β-tocotrienol and the total vitamin E content in Arabidopsis seeds. Furthermore, these transgenic Arabidopsis seeds exhibited an accelerated germination time, compared with wild-type seeds under normal conditions, as well as under NaCl and ABA treatments. Meanwhile, the expression level of several genes associated with ABA biosynthesis (NCED3, NCED5 and NCED9) and the ABA signaling pathway (RAB18, ABI3 and ABI5) were significantly down-regulated in MsHPPD-overexpressing transgenic lines, as well as the total free ABA content. Taken together, these results demonstrate that MsHPPD functions not only in the vitamin E biosynthetic pathway, but also plays a critical role in seed germination via affecting ABA biosynthesis and signaling. PMID:28084442

  10. Analysis of Valproic Acid, Salicylic Acid and Ibuprofen in Whole Blood by GC-MS.

    PubMed

    Stephenson, Jon B; Flater, Melanie L; Bain, Lisa T

    2016-10-01

    The Georgia Bureau of Investigation utilized a silylation method of analysis for low molecular weight carboxylic acids in the past. Due to the negative impact such derivatizations can have on gas chromatography-mass spectrometry (GC-MS) systems an alternative means of analysis was investigated. The described method is a whole blood solid phase extraction of valproic acid, salicylic acid and ibuprofen utilizing butylation for sensitivity and improved chromatography by GC-MS. The method produced a limit of detection and limit of quantitation at 1 mg/L for valproic acid, 2 mg/L for salicylic acid and 0.25 mg/L for ibuprofen. The variability based upon the middle of the calibration curve estimated to be 7% for valproic acid, 8% for salicylic acid and 11% for ibuprofen established upon a 95% confidence interval, with the highest percent coefficient of variation being 5.3% for ibuprofen.

  11. Synthesis and Characterization of Fatty Acid Conjugates of Niacin and Salicylic Acid.

    PubMed

    Vu, Chi B; Bemis, Jean E; Benson, Ericka; Bista, Pradeep; Carney, David; Fahrner, Richard; Lee, Diana; Liu, Feng; Lonkar, Pallavi; Milne, Jill C; Nichols, Andrew J; Picarella, Dominic; Shoelson, Adam; Smith, Jesse; Ting, Amal; Wensley, Allison; Yeager, Maisy; Zimmer, Michael; Jirousek, Michael R

    2016-02-11

    This report describes the synthesis and preliminary biological characterization of novel fatty acid niacin conjugates and fatty acid salicylate conjugates. These molecular entities were created by covalently linking two bioactive molecules, either niacin or salicylic acid, to an omega-3 fatty acid. This methodology allows the simultaneous intracellular delivery of two bioactives in order to elicit a pharmacological response that could not be replicated by administering the bioactives individually or in combination. The fatty acid niacin conjugate 5 has been shown to be an inhibitor of the sterol regulatory element binding protein (SREBP), a key regulator of cholesterol metabolism proteins such as PCSK9, HMG-CoA reductase, ATP citrate lyase, and NPC1L1. On the other hand, the fatty acid salicylate conjugate 11 has been shown to have a unique anti-inflammatory profile based on its ability to modulate the NF-κB pathway through the intracellular release of the two bioactives.

  12. Abscisic acid form, concentration, and application timing influence phenology and bud cold hardiness in Merlot grapevines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of abscisic acid (ABA) form, concentration and application timing on bud cold hardiness, phenology and fruiting performance on ‘Merlot’ grapevines (Vitis vinifera) were evaluated in a three year field trial with site locations in British Columbia Canada, Ontario Canada, Washington U.S. ...

  13. Abscisic acid (ABA) receptors: light at the end of the tunnel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plant hormone abscisic acid (ABA) plays a role in several aspects of plant growth and development. Understanding how this hormonal stimulus is sensed and transduced turned out to be one of the major tasks in the field of plant signaling. A series of recent papers proposed several different prote...

  14. Effects of high night temperature and abscisic acid (ABA) on rice (Oryza sativa L.) physiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High night temperature (HNT) is known to decrease rice yields. The impact of abscisic acid (ABA) on plants has been the subject of many studies. However, little or no work has been carried out on rice response to ABA under HNT-stress conditions. This study determined the effects of ABA on rice leaf ...

  15. Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tea [Camellia sinensis (L.) O. Kuntze] is an important economic crop, and drought is the most important abiotic stress affecting yield and quality. Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance. Increased understanding of ABA effects on tea plant unde...

  16. Postharvest chitosan-g-salicylic acid application alleviates chilling injury and preserves cucumber fruit quality during cold storage.

    PubMed

    Zhang, Youzuo; Zhang, Meiling; Yang, Huqing

    2015-05-01

    The effect of salicylic acid with and without chitosan, or a chitosan-g-salicylic acid complex, on chilling injury and post-harvest quality of cucumber stored at 2 °C for 12 days plus 2 days at 20 °C was investigated. The results showed the chitosan-g-salicylic acid coating inhibited chilling injury better than salicylic acid alone or with chitosan. Chitosan-g-salicylic acid also reduced weight loss and respiration rate, limited increases in malondialdehyde content and electrolyte leakage, and maintained higher total soluble solids, chlorophyll and ascorbic acid content. Furthermore, this coating increased the endogenous salicylic acid concentrations and antioxidant enzyme activities including superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase in cucumber during storage. Our study suggests that chitosan-g-salicylic acid alleviated chilling injury in cucumber through sustained-release of salicylic acid and the higher antioxidant enzymes concentrations.

  17. Involvement of phospholipase D and NADPH-oxidase in salicylic acid signaling cascade.

    PubMed

    Kalachova, Tetiana; Iakovenko, Oksana; Kretinin, Sergii; Kravets, Volodymyr

    2013-05-01

    Salicylic acid is associated with the primary defense responses to biotic stress and formation of systemic acquired resistance. However, molecular mechanisms of early cell reactions to phytohormone application are currently undisclosed. The present study investigates the participation of phospholipase D and NADPH-oxidase in salicylic acid signal transduction cascade. The activation of lipid signaling enzymes within 15 min of salicylic acid application was shown in Arabidopsis thaliana plants by measuring the phosphatidic acid accumulation. Adding of primary alcohol (1-butanol) to the incubation medium led to phosphatidylbutanol accumulation as a result of phospholipase D (PLD) action in wild-type and NADPH-oxidase RbohD deficient plants. Salicylic acid induced rapid increase in NADPH-oxidase activity in histochemical assay with nitroblue tetrazolium but the reaction was not observed in presence of 1-butanol and NADPH-oxidase inhibitor diphenylene iodide (DPI). The further physiological effect of salicylic acid and inhibitory analysis of the signaling cascade were made in the guard cell model. Stomatal closure induced by salicylic acid was inhibited by 1-butanol and DPI treatment. rbohD transgenic plants showed impaired stomatal reaction upon phytohormone effect, while the reaction to H2O2 did not differ from that of wild-type plants. Thus a key role of NADPH-oxidase D-isoform in the process of stomatal closure in response to salicylic acid has been postulated. It has enabled to predict a cascade implication of PLD and NADPH oxidase to salicylic acid signaling pathway.

  18. Salicylic acid is important for basal defense of Solanum tuberosum against Phytophthora infestans.

    PubMed

    Halim, Vincentius A; Eschen-Lippold, Lennart; Altmann, Simone; Birschwilks, Mandy; Scheel, Dierk; Rosahl, Sabine

    2007-11-01

    The importance of the signaling compound salicylic acid for basal defense of potato (Solanum tuberosum L. cv. Désirée) against Phytophthora infestans, the causal agent of late blight disease, was assessed using transgenic NahG potato plants which are unable to accumulate salicylic acid. Although the size of lesions caused by P. infestans was not significantly different in wild-type and transgenic NahG plants, real-time polymerase chain reaction analyses revealed a drastic enhancement of pathogen growth in potato plants depleted of salicylic acid. Increased susceptibility of NahG plants correlated with compromised callose formation and reduced early defense gene expression. NahG plants pretreated with the salicylic acid analog 2,6-dichloro-isonicotinic acid allowed pathogen growth to a similar extent as did wild-type plants, indicating that salicylic acid is an important compound required for basal defense of potato against P. infestans.

  19. A rapid biosensor-based method for quantification of free and glucose-conjugated salicylic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salicylic acid (SA) is an important signalling molecule in plant defenses against biotrophic pathogens. It is also involved in several other processes such as heat production, flowering, and germination. SA exists in the plant as free SA and as an inert glucose conjugate (salicylic acid 2-O-ß-D-...

  20. Identification of genes regulated by UV/salicylic acid.

    SciTech Connect

    Paunesku, T.; Chang-Liu, C.-M.; Shearin-Jones, P.; Watson, C.; Milton, J.; Oryhon, J.; Salbego, D.; Milosavljevic, A.; Woloschak, G. E.; CuraGen Corp.

    2000-02-01

    Purpose : Previous work from the authors' group and others has demonstrated that some of the effects of UV irradiation on gene expression are modulated in response to the addition of salicylic acid to irradiated cells. The presumed effector molecule responsible for this modulation is NF-kappaB. In the experiments described here, differential-display RT-PCR was used to identify those cDNAs that are differentially modulated by UV radiation with and without the addition of salicylic acid. Materials and methods : Differential-display RT-PCR was used to identify differentially expressed genes. Results : Eight such cDNAs are presented: lactate dehydrogenase (LDH-beta), nuclear encoded mitochondrial NADH ubiquinone reductase 24kDa (NDUFV2), elongation initiation factor 4B (eIF4B), nuclear dots protein SP100, nuclear encoded mitochondrial ATPase inhibitor (IF1), a cDNA similar to a subunit of yeast CCAAT transcription factor HAP5, and two expressed sequence tags (AA187906 and AA513156). Conclusions : Sequences of four of these genes contained NF-kappaB DNA binding sites of the type that may attract transrepressor p55/p55 NF-kappaB homodimers. Down-regulation of these genes upon UV irradiation may contribute to increased cell survival via suppression of p53 independent apoptosis.

  1. Aluminum Chloride Hexahydrate in a Salicylic Acid Gel

    PubMed Central

    Valins, Whitney

    2009-01-01

    Hyperhidrosis is a common dermatological condition that has a tremendous impact on the quality of life of affected patients. Aluminum chloride hexahydrate is considered first-line therapy for patients with mild-to-moderate hyperhidrosis. This treatment has been proven to be effective in the treatment of hyperhidrosis; however, its use has been limited by significant irritation. In many patients, the irritant dermatitis is so severe that, despite clinical efficacy, this therapy must be discontinued. There are many topical aluminum chloride therapies available. Observations from a busy hyperhidrosis practice revealed decreased irritation and increased efficacy with a novel therapy that combines 15% aluminum chloride hexahydrate with 2% salicylic acid in a gel base. This combination of 15% aluminum chloride hexahydrate with 2% salicylic acid offers patients who have failed aluminum chloride hexahydrate in the past excellent efficacy with minimal irritation. We report seven cases of patients with a history of severe irritation from aluminum chloride who maintained excellent results with this new topical without any significant irritation. PMID:20729946

  2. Simultaneous determination of salicylic, 3-methyl salicylic, 4-methyl salicylic, acetylsalicylic and benzoic acids in fruit, vegetables and derived beverages by SPME-LC-UV/DAD.

    PubMed

    Aresta, Antonella; Zambonin, Carlo

    2016-03-20

    Salicylic and benzoic acid are phenolic acids occurring in plant cells, thus they can be present in fruit and vegetables at various levels. They possess anti-inflammatory and antimicrobial properties, however they may induce symptoms and health problems in a small percentage of the population. Therefore, a low phenolic acid diet may be of clinical benefit to such individuals. In order to achieve this goal, the concentration of these substances in different food and beverages should be assessed. The present work describes for the first time a new method, based on solid phase microextraction (polydimethylsiloxane-divinylbenzene fiber) coupled to liquid chromatography with UV diode array detection, for the simultaneous determination of salicylic acid, 3-methyl salicylic acid, 4-methyl salicylic acid, acetylsalicylic acid and benzoic acid in selected fruit, vegetables and beverages. All the aspects influencing fiber adsorption (time, temperature, pH, salt addition) and desorption (desorption and injection time, desorption solvent mixture composition) of the analytes have been investigated. An isocratic separation was performed using an acetonitrile-phosphate buffer (pH 2.8; 2 mM) mixture (70:30, v/v) as the mobile phase. The estimated LOD and LOQ values (μg/mL) were in the range 0.002-0.028 and 0.007-0.095. The within-day and day-to-day precision values (RSD%) were between 4.7-6.1 and 6.6-9.4, respectively. The method has been successfully applied to the analysis of fava beans, blueberries, kiwi, tangerines, lemons, oranges and fruit juice (lemon and blueberry) samples. The major advantage of the method is that it only requires simple homogenization and/or centrifugation and dilution steps prior to SPME and injection in the LC system.

  3. Two glucosylated abscisic acid derivates from avocado seeds (Persea americana Mill. Lauraceae cv. Hass).

    PubMed

    del Refugio Ramos, María; Jerz, Gerold; Villanueva, Socorro; López-Dellamary, Fernando; Waibel, Reiner; Winterhalter, Peter

    2004-04-01

    Phytochemical investigation of avocado seed material (Persea americana Mill., Lauraceae) resulted in the isolation of two glucosylated abscisic acid derivates. One of these was not known as a natural product and can be regarded as a potential 'missing link' in abscisic acid metabolism in plants. After fractionation by high-speed countercurrent chromatography, and multiple steps of column chromatography, structures were elucidated by 1D-, 2D-NMR, electrospray-MS to be the novel beta-d-glucoside of (1'S,6'R)-8'-hydroxyabscisic acid, and (1'R,3'R,5'R,8'S)-epi-dihydrophaseic acid beta-d-glucoside. Absolute configuration was determined by circulardichroism, optical rotation, and by NOE experiments.

  4. Use of jasmonic acid and salicylic acid to inhibit growth of sugarbeet storage rot pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Jasmonic acid (JA) and salicylic acid (SA) are endogenous plant hormones that induce native plant defense responses and provide protection against a wide range of diseases. Previously, JA, applied after harvest, was shown to protect sugarbeet roots against the storage pathogens, Botrytis cinerea, P...

  5. Determination of salicylic acid by HPLC in plasma and saliva from children with juvenile chronic arthritis.

    PubMed

    Legaz, M E; Acitores, E; Valverde, F

    1992-12-01

    A high performance liquid chromatography (HPLC) method has been developed for measuring salicylic acid in the plasma and saliva of children with juvenile chronic arthritis (JCA). Samples were extracted with diethyl ether and, after drying, redissolved in methanol to be chromatographed. Quantitation of salicylic acid was performed by reverse phase HPLC on a spherisorb ODS-2 column, using methanol: water: acetic acid as mobile phase. Phenolic was monitored by absorbance at 237 nm. Linearity between the amount of mass injected and the response in the detector was determined. This method was applied to compare concentrations of salivary and plasma salicylic acid. The method also permitted the quantitation of salivary salicylate as a non-invasive, indirect method for monitoring the concentration of plasma salicylate in patients with JCA.

  6. Salicylic Acid Induction of Flavonoid Biosynthesis Pathways in Wheat Varies by Treatment

    PubMed Central

    Gondor, Orsolya K.; Janda, Tibor; Soós, Vilmos; Pál, Magda; Majláth, Imre; Adak, Malay K.; Balázs, Ervin; Szalai, Gabriella

    2016-01-01

    Salicylic acid is a promising compound for the reduction of stress sensitivity in plants. Although several biochemical and physiological changes have been described in plants treated with salicylic acid, the mode of action of the various treatments has not yet been clarified. The present work reports a detailed comparative study on the effects of different modes of salicylic acid application at the physiological, metabolomic, and transcriptomic levels. Seed soaking and hydroponic treatments were found to induce various changes in the protective mechanisms of wheat plants. The possible involvement of the flavonoid metabolism in salicylic acid-related stress signaling was also demonstrated. Different salicylic acid treatments were shown to induce different physiological and biochemical processes, with varying responses in the leaves and roots. Hydroponic treatment enhanced the level of oxidative stress, the expression of genes involved in the flavonoid metabolism and the amount of non-enzymatic antioxidant compounds, namely ortho-hydroxycinnamic acid and the flavonol quercetin in the leaves, while it decreased the ortho-hydroxycinnamic acid and flavonol contents and enhanced ascorbate peroxidase activity in the roots. In contrast, seed soaking only elevated the gene expression level of phenylalanine ammonia lyase in the roots and caused a slight increase in the amount of flavonols. These results draw attention to the fact that the effects of exogenous salicylic acid application cannot be generalized in different experimental systems and that the flavonoid metabolism may be an important part of the action mechanisms induced by salicylic acid. PMID:27733857

  7. Salicylic Acid Induction of Flavonoid Biosynthesis Pathways in Wheat Varies by Treatment.

    PubMed

    Gondor, Orsolya K; Janda, Tibor; Soós, Vilmos; Pál, Magda; Majláth, Imre; Adak, Malay K; Balázs, Ervin; Szalai, Gabriella

    2016-01-01

    Salicylic acid is a promising compound for the reduction of stress sensitivity in plants. Although several biochemical and physiological changes have been described in plants treated with salicylic acid, the mode of action of the various treatments has not yet been clarified. The present work reports a detailed comparative study on the effects of different modes of salicylic acid application at the physiological, metabolomic, and transcriptomic levels. Seed soaking and hydroponic treatments were found to induce various changes in the protective mechanisms of wheat plants. The possible involvement of the flavonoid metabolism in salicylic acid-related stress signaling was also demonstrated. Different salicylic acid treatments were shown to induce different physiological and biochemical processes, with varying responses in the leaves and roots. Hydroponic treatment enhanced the level of oxidative stress, the expression of genes involved in the flavonoid metabolism and the amount of non-enzymatic antioxidant compounds, namely ortho-hydroxycinnamic acid and the flavonol quercetin in the leaves, while it decreased the ortho-hydroxycinnamic acid and flavonol contents and enhanced ascorbate peroxidase activity in the roots. In contrast, seed soaking only elevated the gene expression level of phenylalanine ammonia lyase in the roots and caused a slight increase in the amount of flavonols. These results draw attention to the fact that the effects of exogenous salicylic acid application cannot be generalized in different experimental systems and that the flavonoid metabolism may be an important part of the action mechanisms induced by salicylic acid.

  8. A GC-ECD method for estimation of free and bound amino acids, gamma-aminobutyric acid, salicylic acid, and acetyl salicylic acid from Solanum lycopersicum (L.).

    PubMed

    Meher, Hari Charan; Gajbhiye, Vijay T; Singh, Ghanendra

    2011-01-01

    A gas chromatograph with electron capture detection method for estimation of selected metabolites--amino acids (free and bound), gamma-aminobutyric acid (GABA), salicylic acid (SA), and acetyl salicylic acid (ASA) from tomato--is reported. The method is based on nitrophenylation of the metabolites by 1-fluoro-2, 4-dinitrobenzene under aqueous alkaline conditions to form dinitophenyl derivatives. The derivatives were stable under the operating conditions of GC. Analysis of bound amino acids comprised perchloric acid precipitation of protein, alkylation (carboxymethylation) with iodoacetic acid, vapor-phase hydrolysis, and derivatization with 1-fluoro-2,4-dinitrobenzene in that order. The metabolites were resolved in 35 min, using a temperature-programmed run. The method is rapid, sensitive, and precise. It easily measured the typical amino acids (aspartate, asparagine, glutamate, glutamine, alanine, leucine, lysine, and phenylalanine) used for identification and quantification of a protein, resolved amino acids of the same mass (leucine and isoleucine), satisfactorily measured sulfur amino acid (methionine, cystine, and cysteine), and quantified GABA, SA, and ASA, as well. The developed method was validated for specificity, linearity, and precision. It has been applied and recommended for estimation of 25 metabolites from Solanum lycopersicum (L.).

  9. Disruption of Abscisic Acid Signaling Constitutively Activates Arabidopsis Resistance to the Necrotrophic Fungus Plectosphaerella cucumerina1[W

    PubMed Central

    Sánchez-Vallet, Andrea; López, Gemma; Ramos, Brisa; Delgado-Cerezo, Magdalena; Riviere, Marie-Pierre; Llorente, Francisco; Fernández, Paula Virginia; Miedes, Eva; Estevez, José Manuel; Grant, Murray; Molina, Antonio

    2012-01-01

    Plant resistance to necrotrophic fungi is regulated by a complex set of signaling pathways that includes those mediated by the hormones salicylic acid (SA), ethylene (ET), jasmonic acid (JA), and abscisic acid (ABA). The role of ABA in plant resistance remains controversial, as positive and negative regulatory functions have been described depending on the plant-pathogen interaction analyzed. Here, we show that ABA signaling negatively regulates Arabidopsis (Arabidopsis thaliana) resistance to the necrotrophic fungus Plectosphaerella cucumerina. Arabidopsis plants impaired in ABA biosynthesis, such as the aba1-6 mutant, or in ABA signaling, like the quadruple pyr/pyl mutant (pyr1pyl1pyl2pyl4), were more resistant to P. cucumerina than wild-type plants. In contrast, the hab1-1abi1-2abi2-2 mutant impaired in three phosphatases that negatively regulate ABA signaling displayed an enhanced susceptibility phenotype to this fungus. Comparative transcriptomic analyses of aba1-6 and wild-type plants revealed that the ABA pathway negatively regulates defense genes, many of which are controlled by the SA, JA, or ET pathway. In line with these data, we found that aba1-6 resistance to P. cucumerina was partially compromised when the SA, JA, or ET pathway was disrupted in this mutant. Additionally, in the aba1-6 plants, some genes encoding cell wall-related proteins were misregulated. Fourier transform infrared spectroscopy and biochemical analyses of cell walls from aba1-6 and wild-type plants revealed significant differences in their Fourier transform infrared spectratypes and uronic acid and cellulose contents. All these data suggest that ABA signaling has a complex function in Arabidopsis basal resistance, negatively regulating SA/JA/ET-mediated resistance to necrotrophic fungi. PMID:23037505

  10. Paper-based electroanalytical devices for in situ determination of salicylic acid in living tomato leaves.

    PubMed

    Sun, Li-Jun; Feng, Qiu-Mei; Yan, Yong-Feng; Pan, Zhong-Qin; Li, Xiao-Hui; Song, Feng-Ming; Yang, Haibing; Xu, Jing-Juan; Bao, Ning; Gu, Hai-Ying

    2014-10-15

    Detection of phytohormones in situ has gained significant attention due to their critical roles in regulating developmental processes and signaling for defenses in plants at low concentration. As one type of plant hormones, salicylic acid has recently been found to be one of pivotal signal molecules for physiological behaviors of plants. Here we report the application of paper-based electroanalytical devices for sensitively in situ detection of salicylic acid in tomato leaves with the sample volume of several microliters. Specifically, disposable working electrodes were fabricated by coating carbon tape with the mixture of multiwall carbon nanotubes and nafion. We observed that the treatment of the modified carbon tape electrodes with oxygen plasma could significantly improve electrochemical responses of salicylic acid. The tomato leaves had a punched hole of 1.5mm diameter to release salicylic acid with minor influence on continuous growth of tomatoes. By incorporating the tomato leaf with the paper-based analytical device, we were able to perform in situ determination of salicylic acid based on its electrocatalytic oxidation. Our experimental results demonstrated that the amounts of salicylic acid differed statistically in normal, phytoene desaturase (PDS) gene silent and diseased (infected by Botrytis cinerea) tomato leaves. By quantifying salicylic acid at the level of several nanograms in situ, the simple paper-based electroanalytical devices could potentially facilitate the study of defense mechanism of plants under biotic and abiotic stresses. This study might also provide a sensitive method with spatiotemporal resolution for mapping of chemicals released from living organisms.

  11. Alleviation of salt stress in lemongrass by salicylic acid.

    PubMed

    Idrees, Mohd; Naeem, M; Khan, M Nasir; Aftab, Tariq; Khan, M Masroor A; Moinuddin

    2012-07-01

    Soil salinity is one of the key factors adversely affecting the growth, yield, and quality of crops. A pot study was conducted to find out whether exogenous application of salicylic acid could ameliorate the adverse effect of salinity in lemongrass (Cymbopogon flexuosus Steud. Wats.). Two Cymbopogon varieties, Krishna and Neema, were used in the study. Three salinity levels, viz, 50, 100, and 150 mM of NaCl, were applied to 30-day-old plants. Salicylic acid (SA) was applied as foliar spray at 10(-5) M concentration. Totally, six SA-sprays were carried out at 10-day intervals, following the first spray at 30 days after sowing. The growth parameters were progressively reduced with the increase in salinity level; however, growth inhibition was significantly reduced by the foliar application of SA. With the increase in salt stress, a gradual decrease in the activities of carbonic anhydrase and nitrate reductase was observed in both the varieties. SA-treatment not only ameliorated the adverse effects of NaCl but also showed a significant improvement in the activities of these enzymes compared with the untreated stressed-plants. The plants supplemented with NaCl exhibited a significant increase in electrolyte leakage, proline content, and phosphoenol pyruvate carboxylase activity. Content and yield of essential oil was also significantly decreased in plants that received salinity levels; however, SA overcame the unfavorable effects of salinity stress to a considerable extent. Lemongrass variety Krishna was found to be more adapted to salt stress than Neema, as indicated by the overall performance of the two varieties under salt conditions.

  12. Abscisic acid (ABA) receptors: light at the end of the tunnel

    PubMed Central

    McCormick, Sheila

    2010-01-01

    The plant hormone abscisic acid (ABA) plays a role in several aspects of plant growth and development. Understanding how this hormonal stimulus is sensed and transduced turned out to be one of the major tasks in the field of plant signaling. A series of recent papers proposed several different proteins that could receive the ABA signal and initiate the signaling cascade. The winner appears to be PYR/PYL/RCAR (PYrabactin Resistance/PYrabactin Resistance-Like/Regulatory Component of Abscisic acid Receptor) proteins, as crystal structures were recently published. The crystal structures support the idea that upon ABA binding to a PYR/PYL/RCAR protein, the activity of a phosphatase 2C, with known repressive activity on ABA signaling, is inhibited. PMID:20948817

  13. Abscisic Acid Levels during Early Seed Development in Sechium edule Sw

    PubMed Central

    Vernieri, Paolo; Perata, Pierdomenico; Lorenzi, Roberto; Ceccarelli, Nello

    1989-01-01

    The time-course growth of single tissues in pollinated and unpollinated ovules of Sechium edule Sw. is described in relation to the endogenous levels of abscisic acid. Quantitation of abscisic acid (ABA) in the minute amounts of material obtained after ovule dissection has been performed by using a highly specific and sensitive solid-phase radioimmunoassay based on a monoclonal antibody raised against free (S)-ABA. While the absolute amount of ABA rises in both types of ovules, only in unpollinated ones does this leads to an increase in the hormone concentration. Infact in pollinated ovules the rapid growth following pollination prevents, through a dilution effect, the increase in ABA concentration. Growth patterns and endogenous ABA levels are similar for integuments and nucellus tissues either in pollinated or unpollinated ovules. It is suggested that the growth inhibition induced by the increase in ABA concentration after anthesis could be counteracted by the pollination triggered fast ovule growth. PMID:16667185

  14. Potentiometric membrane electrode for salicylate based on an organotin complex with a salicylal Schiff base of amino acid.

    PubMed

    Xu, Lan; Yuan, Ruo; Fu, Ying-Zi; Chai, Ya-Qin

    2005-03-01

    A novel salicylate-selective electrode based on an organotin complex with a salicylal Schiff base of amino acid salicylaldehydeaminoacid-di-n-butyl-Sn(IV) [Sn(IV)-SAADB] as ionophore is described, which exhibits high selectivity for salicylate over many other common anions with an anti-Hofmeister selectivity sequence: Sal- > PhCOO- > SCN- > Cl04- > I- > NO3- > NO2- > Br- > Cl- > CH3COO-. The electrode, based on Sn(IV)-SAADB, with a 30.44 wt% PVC, a 65.45 wt% plasticizer (dioctyl phthalate, DOP), a 3.81 wt% ionophore and a 0.3 wt% anionic additive is linear in 6.0 x 10(-6) - 1.0 x 10(-1) mol l(-1) with a detection limit of 2.0 x 10(-6) mol l(-1) and a slope of 62.0 +/- 1.2 mV/decade of salicylate concentration in a phosphate buffer solution of pH 5.5 at 25 degrees C. The influence on the electrode performances by lipophilic charged additives was studied, and the possible response mechanism was investigated by UV spectra. The electrode was applied to medicine analysis and the result obtained has been satisfactory.

  15. Salicylic acid and some of its derivatives as antibacterial agents for viscose fabric.

    PubMed

    Kantouch, A; El-Sayed, A Atef; Salama, M; El-Kheir, A Abou; Mowafi, S

    2013-11-01

    Salicylic acid and three of its derivatives were used to provide antibacterial properties to viscose fabrics. The four bactericides used were bonded to the viscose fabrics using epichlorohydrin or polymer binders. Optimization of the salicylic acid and its derivatives as well as the concentration of polymers was reported. The ability of the polymer binders to attract and bind the four bactericides was observed. The overall results show that the antibacterial reactivity of salicylic acid and its derivatives are in the following order 5-bromosalicylic acid>salicylic acid>5-chlorosalicylic acid>4-chlorosalicylic acid. Using epichlorohydrin as a binding agent, unfortunately, inhibits the bactericidal activity of the four bactericides. The FTIR study concludes that the reaction between salicylic acid as well as its derivatives with epichlorohydrin takes place through the phenolic group of the acids. The unexpected deterioration in the bactericidal properties of salicylic acid and its derivatives as a result of the treatment with epichlorohydrin could be due to the nature of interaction between the epichlorohydrin molecule and the acids molecules. PVP and PU show superior ability to sustain the four bactericides used even after 10 washing cycles.

  16. Rapid adjustment of guard-cell abscisic acid levels to current leaf-water status

    SciTech Connect

    Harris, M.J.; Outlaw, W.H. Jr. )

    1991-01-01

    Detached broad bean (Vicia faba L.) leaflets were water stressed; within 15 minutes, guard-cell abscisic acid (ABA) concentration increased ninefold. This result eliminates the apparent discrepancy raised by reports of no correlation between initial water-stress effects on stomata and leaf ABA concentration. Six hours after stress relief, guard-cell ABA concentration was near the prestress value, which would seem to implicate other factors in stress after-effects on stomata.

  17. Abscisic acid is not necessary for gravitropism in primary roots of Zea mays

    NASA Technical Reports Server (NTRS)

    Moore, R.

    1990-01-01

    Primary roots of Zea mays L. cv. Tx 5855 treated with fluridone are strongly graviresponsive, but have undetectable levels of abscisic acid (ABA). Primary roots of the carotenoid-deficient w-3, vp-5, and vp-7 mutants of Z. mays are also graviresponsive despite having undetectable amounts of ABA. Graviresponsive roots of untreated and wild-type seedlings contain 286 to 317 ng ABA g-1 f. wt, respectively. These results indicate that ABA is not necessary for root gravicurvature.

  18. Simultaneous determination of acetylsalicylic and salicylic acids by first derivative spectrometry in pharmaceutical preparations

    NASA Astrophysics Data System (ADS)

    Rogić, Dunja

    1993-03-01

    A multicomponent first derivative UV spectrometric procedure for determination of acetylsalicylic acid (aspirin) and salicylic acid in the solution containing 1 % (w/v) of citric acid in some pharmaceutical preparations is presented. The method is based on the use of the first derivative minimum spectrometric measurements at 286 nm for aspirin and at 318 nm for salicylic acid. Four kinds of cmmercial Aspirin tablets were assayed without a long pretreatment of the pharmaceuticals from the tablet additives. Beer's law is obeyed from 13.62-68.1 μg ml -1 of aspirin and from 2.723-13.616 μg ml -1 of salicylic acid. Detection limits at the 0.05 level of significance were calculated to be 1.24 and 0.25 μg ml -1 with relative standard deviations of 1.09 % and 1.2 % of aspirin and salicylic acid, respectively.

  19. Effects of copper on chlorophyll, proline, protein and abscisic acid level of sunflower (Helianthus annuus L.) seedlings.

    PubMed

    Zengin, Fikriye Kirbag; Kirbag, Sevda

    2007-07-01

    The effect of copperchloride (CuCl2) on the level of chlorophyll (a+b), proline, protein and abscisic acid in sunflower (Helianthus annuus L.) seedlings were investigated Control and copper treated (0.4, 0.5 and 0.6 mM) seedlings were grown for ten days in Hoagland solution. Abscisic acid content was determined in root, shoot and leaf tissues of seedlings by HPLC. Copper stress caused significant increase of the abscisic acid contents in roots, shoots and leaves of seedlings. The increase was dependent on the copper salt concentration. Enhanced accumulation of proline in the leaves of seedlings exposed to copper was determined, as well as a decrease of chlorophyll (a+b) and total protein (p < 0.05 or p < 0.01). It was observed that the level of chlorophyll (a+b) and total protein (p < 0.05 or p < 0.01) remarkably decreased as copper concentration increased to 0.6 mM, although the levels of proline and abscisic acid in the leaves of plants were increased--a dose-depended behavior The same trends were also observed with the level of abscisic acid of stems and roots. Copper has dose- depended effects on chlorophyll, proline, protein and abscisic acid level of sunflower (Helianthus annuus L.) seedlings. Thus, we assumed that copper levels increase above some critical points seedling growth get negative effects. This assumption is in line with previous findings.

  20. Overexpression of a soybean salicylic acid methyltransferase gene confers resistance to soybean cyst nematode.

    PubMed

    Lin, Jingyu; Mazarei, Mitra; Zhao, Nan; Zhu, Junwei J; Zhuang, Xiaofeng; Liu, Wusheng; Pantalone, Vincent R; Arelli, Prakash R; Stewart, Charles N; Chen, Feng

    2013-12-01

    Salicylic acid plays a critical role in activating plant defence responses after pathogen attack. Salicylic acid methyltransferase (SAMT) modulates the level of salicylic acid by converting salicylic acid to methyl salicylate. Here, we report that a SAMT gene from soybean (GmSAMT1) plays a role in soybean defence against soybean cyst nematode (Heterodera glycines Ichinohe, SCN). GmSAMT1 was identified as a candidate SCN defence-related gene in our previous analysis of soybean defence against SCN using GeneChip microarray experiments. The current study started with the isolation of the full-length cDNAs of GmSAMT1 from a SCN-resistant soybean line and from a SCN-susceptible soybean line. The two cDNAs encode proteins of identical sequences. The GmSAMT1 cDNA was expressed in Escherichia coli. Using in vitro enzyme assays, E. coli-expressed GmSAMT1 was confirmed to function as salicylic acid methyltransferase. The apparent Km value of GmSAMT1 for salicylic acid was approximately 46 μM. To determine the role of GmSAMT1 in soybean defence against SCN, transgenic hairy roots overexpressing GmSAMT1 were produced and tested for SCN resistance. Overexpression of GmSAMT1 in SCN-susceptible backgrounds significantly reduced the development of SCN, indicating that overexpression of GmSAMT1 in the transgenic hairy root system could confer resistance to SCN. Overexpression of GmSAMT1 in transgenic hairy roots was also found to affect the expression of selected genes involved in salicylic acid biosynthesis and salicylic acid signal transduction.

  1. Abscisic acid and blue light signaling pathways in chloroplast movements in Arabidopsis mesophyll.

    PubMed

    Eckstein, Aleksandra; Krzeszowiec, Weronika; Banaś, Agnieszka Katarzyna; Janowiak, Franciszek; Gabryś, Halina

    2016-01-01

    Abscisic acid (ABA) and phototropins act antagonistically to control stomatal movements. Here, we investigated the role of ABA in phototropin-directed chloroplast movements in mesophyll cells of Arabidopsis thaliana. We analyzed the expression of phototropins at mRNA and protein level under the influence of ABA. PHOT1 mRNA level was decreased by ABA in the dark while it was insensitive to ABA in light. PHOT2 mRNA level was independent of the hormone treatment. The levels of phototropin proteins were down-regulated by ABA, both in darkness and light. No impact of exogenous ABA on amplitudes and kinetics of chloroplast movements was detected. Chloroplast responses in wild type Arabidopsis and three mutants, abi4, abi2 (abscisic acid insensitive4, 2) and aba1 (abscisic acid1), were measured to account for endogenous ABA signaling. The chloroplast responses were slightly reduced in abi2 and aba1 mutants in strong light. To further investigate the effect, abi2 and aba1 mutants were supplemented with exogenous ABA. In the aba1 mutant, the reaction was rescued but in abi2 it was unaffected. Our results show that ABA is not directly involved in phototropin-controlled chloroplast responses in mature leaves of Arabidopsis. However, the disturbance of ABA biosynthesis and signaling in mutants affects some elements of the chloroplast movement mechanism. In line with its role as a stress hormone, ABA appears to enhance plant sensitivity to light and promote the chloroplast avoidance response.

  2. Study on the kinetics and transformation products of salicylic acid in water via ozonation.

    PubMed

    Hu, Ruikang; Zhang, Lifeng; Hu, Jiangyong

    2016-06-01

    As salicylic acid is one of widely used pharmaceuticals, its residue has been found in various environmental water systems e.g. wastewater, surface water, treated water and drinking water. It has been reported that salicylic acid can be efficiently removed by advanced oxidation processes, but there are few studies on its transformation products and ozonation mechanisms during ozonation process. The objective of this study is to characterize the transformation products, investigate the degradation mechanisms at different pH, and propose the ozonation pathways of salicylic acid. The results showed that the rate of degradation was about 10 times higher at acidic condition than that at alkaline condition in the first 1 min when 1 mg L(-1) of ozone solution was added into 1 mg L(-1) of salicylic acid solution. It was proposed that ozone direct oxidation mechanism dominates at acidic condition, while indirect OH radical mechanism dominates at alkaline condition. A two stages pseudo-first order reaction was proposed at different pH conditions. Various hydroxylation products, carbonyl compounds and carboxylic acids, such as 2,5-dihydroxylbenzoic acid, 2,3-dihydroxylbenzoic acid, catechol, formaldehyde, glyoxal, acetaldehyde, maleic acid, acetic acid and oxalic acid etc. were identified as ozonation transformation products. In addition, acrylic acid was identified, for the first time, as ozonation transformation products through high resolution liquid chromatography-time of flight mass spectrometer. The information demonstrated in this study will help us to better understand the possible effects of ozonation products on the water quality. The degradation pathways of salicylic acid by ozonation in water sample were proposed. As both O3 and OH radical were important in the reactions, the degradation pathways of salicylic acid by ozonation in water sample were proposed at acidic and basic conditions. To our knowledge, there was no integrated study reported on the ozonation of

  3. HPLC analysis of in vivo intestinal absorption and oxidative metabolism of salicylic acid in the rat.

    PubMed

    Kuzma, Mónika; Nyúl, Eszter; Mayer, Mátyás; Fischer, Emil; Perjési, Pál

    2016-12-01

    In vivo absorption and oxidative metabolism of salicylic acid in rat small intestine was studied by luminal perfusion experiment. Perfusion through the lumen of proximal jejunum with isotonic medium containing 250 μm sodium salicylate was carried out. Absorption of salicylate was measured by a validated HPLC-DAD method which was evaluated for a number of validation characteristics (specificity, repeatability and intermediate precision, limit of detection, limit of quantification, linearity and accuracy). The method was linear over the concentration range 0.5-50 μg/mL. After liquid-liquid extraction of the perfusion samples oxidative biotransformation of salicylate was also investigated by HPLC-MS. The method was linear over the concentration range 0.25-5.0 μg/mL. Two hydroxylated metabolites of salicylic acid (2,5-dihydroxybenzoic acid and 2,3-dihydroxybenzoic acid) were detected and identified. The mean recovery of extraction was 72.4% for 2,3-DHB, 72.5% for 2,5-DHB and 50.1% for salicylic acid, respectively. The methods were successfully applied to investigate jejunal absorption and oxidative metabolism of sodium salicylate in experimental animals. The methods provide analytical background for further metabolic studies of salycilates under modified physiological conditions.

  4. Induction of phytic acid synthesis by abscisic acid in suspension-cultured cells of rice.

    PubMed

    Matsuno, Koya; Fujimura, Tatsuhito

    2014-03-01

    A pathway of phytic acid (PA) synthesis in plants has been revealed via investigations of low phytic acid mutants. However, the regulation of this pathway is not well understood because it is difficult to control the environments of cells in the seeds, where PA is mainly synthesized. We modified a rice suspension culture system in order to study the regulation of PA synthesis. Rice cells cultured with abscisic acid (ABA) accumulate PA at higher levels than cells cultured without ABA, and PA accumulation levels increase with ABA concentration. On the other hand, higher concentrations of sucrose or inorganic phosphorus do not affect PA accumulation. Mutations in the genes RINO1, OsMIK, OsIPK1 and OsLPA1 have each been reported to confer low phytic acid phenotypes in seeds. Each of these genes is upregulated in cells cultured with ABA. OsITPK4 and OsITPK6 are upregulated in cells cultured with ABA and in developing seeds. These results suggest that the regulation of PA synthesis is similar between developing seeds and cells in this suspension culture system. This system will be a powerful tool for elucidating the regulation of PA synthesis.

  5. Effects of Abscisic Acid and Ethylene on the Gibberellic Acid-Induced Synthesis of α-Amylase by Isolated Wheat Aleurone Layers 1

    PubMed Central

    Varty, Keith; Arreguín, Barbarín L.; Gómez, Miguel T.; López, Pablo Jaime T.; Gómez, Miguel Angel L.

    1983-01-01

    Gibberellic acid-induced α-amylase synthesis in wheat aleurone layers (Triticum aestivum L. var Potam S-70) escaped from transcriptional control 30 h after addition of the hormone, as evidenced by the tissue's loss of susceptibility to cordycepin. Abscisic acid inhibited the accumulation of α-amylase activity when added to the tissue during this cordycepin-insensitive phase of enzyme induction. α-Amylase synthesis was not restored by the addition of cordycepin, indicating that the response to abscisic acid was not dependent upon the continuous synthesis of a short lived RNA. When ethylene was added simultaneously or some time after abscisic acid, the accumulation of α-amylase activity was sustained or quickly restored. The loss of susceptibility to cordycepin was completely prevented when aleurone layers were incubated with a combination of gibberellic and abscisic acids from the start of the induction period. This effect of abscisic acid was not reversed by ethylene. On the basis of these observations, it is suggested that abscisic acid inhibits both the transcription and translation of α-amylase mRNA, and that only the latter site of action is susceptible to reversal by ethylene. The rate of incorporation of [methyl-14C]choline into phospholipids was also inhibited by abscisic acid. Ethylene reversed this effect. The effects of abscisic acid and ethylene on phospholipid synthesis were not dependent upon the presence of gibberellic acid. No direct relationship was found between the control of α-amylase synthesis and membrane formation by abscisic acid and ethylene. PMID:16663284

  6. Thermodynamics of the complexation of arabinogalactan with salicylic and p-aminobenzoic acids in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Mudarisova, R. Kh.; Badykova, L. A.

    2016-03-01

    The thermodynamics of complexation of arabinogalactan with salicylic and p-aminobenzoic acids in aqueous solutions is studied by means spectroscopy. The standard thermodynamic characteristics (Δ H°; Δ G°; Δ S°) of complexation are calculated.

  7. Alleviation of postharvest chilling injury of tomato fruit by salicylic acid treatment.

    PubMed

    Aghdam, Morteza Soleimani; Asghari, Mohammadreza; Khorsandi, Orojali; Mohayeji, Mehdi

    2014-10-01

    Tomato fruit at the mature green stage were treated with salicylic acid at different concentration (0, 1 and 2 mM) and analyzed for chilling injury (CI), electrolyte leakage (EL), malondialdehyde (MDA) and proline contents and phospholipase D (PLD) and lipoxygenase (LOX) activities during cold storage. PLD and LOX activities were significantly reduced by salicylic acid treatment. Compared with the control fruit, salicylic acid treatment alleviated chilling injury, reduced electrolyte leakage, malondialdehyde content and increased proline content. Our result suggest that the reduce activity of PLD and LOX, by salicylic acid may be a chilling tolerance strategy in tomato fruit. Inhibition of PLD and LOX activity during low temperature storage could ameliorate chilling injury and oxidation damage and enhance membrane integrity in tomato fruit.

  8. Salicylic acid signaling inhibits apoplastic reactive oxygen species signaling

    PubMed Central

    2014-01-01

    Background Reactive oxygen species (ROS) are used by plants as signaling molecules during stress and development. Given the amount of possible challenges a plant face from their environment, plants need to activate and prioritize between potentially conflicting defense signaling pathways. Until recently, most studies on signal interactions have focused on phytohormone interaction, such as the antagonistic relationship between salicylic acid (SA)-jasmonic acid and cytokinin-auxin. Results In this study, we report an antagonistic interaction between SA signaling and apoplastic ROS signaling. Treatment with ozone (O3) leads to a ROS burst in the apoplast and induces extensive changes in gene expression and elevation of defense hormones. However, Arabidopsis thaliana dnd1 (defense no death1) exhibited an attenuated response to O3. In addition, the dnd1 mutant displayed constitutive expression of defense genes and spontaneous cell death. To determine the exact process which blocks the apoplastic ROS signaling, double and triple mutants involved in various signaling pathway were generated in dnd1 background. Simultaneous elimination of SA-dependent and SA-independent signaling components from dnd1 restored its responsiveness to O3. Conversely, pre-treatment of plants with SA or using mutants that constitutively activate SA signaling led to an attenuation of changes in gene expression elicited by O3. Conclusions Based upon these findings, we conclude that plants are able to prioritize the response between ROS and SA via an antagonistic action of SA and SA signaling on apoplastic ROS signaling. PMID:24898702

  9. Quantification of jasmonic and salicylic acids in rice seedling leaves.

    PubMed

    Cho, Kyoungwon; Han, Oksoo; Tamogami, Shigeru; Shibato, Junko; Kubo, Akihiro; Agrawal, Ganesh Kumar; Rakwal, Randeep

    2013-01-01

    Jasmonic acid (JA) and salicylic acid (SA) are critical signaling components involved in various aspects of plant growth, development, and defense. Their constitutive levels vary from plant to plant and also from tissue to tissue within the same plant. Moreover, their quantitative levels change when plant is exposed to biotic and abiotic stresses. To better understand the JA- and SA-mediated signaling and metabolic pathways, it is important to precisely quantify their levels in plants/tissues/organs. However, their extraction and quantification are not trivial and still technically challenging. An effort has been made in various laboratories to develop a simple and standard procedure that can be utilized for quantification of JA and SA. Here, we present the experimental procedure and our decade of experience on extracting and quantifying them in an absolute manner in leaves of rice seedlings. We must mention that this method has been applied to both monocotyledonous and dicotyledonous plants for absolute quantification of JA and SA. As collaboration is the key towards rapid progress in science and technology, we are always open to sharing our experience in this field with any active research group with an aim to improve the procedure further and eventually to connect the importance of their (JA and SA) quantitative levels with networks of signaling and metabolic pathways in plants.

  10. Evolutionarily conserved regulatory mechanisms of abscisic acid signaling in land plants: characterization of ABSCISIC ACID INSENSITIVE1-like type 2C protein phosphatase in the liverwort Marchantia polymorpha.

    PubMed

    Tougane, Ken; Komatsu, Kenji; Bhyan, Salma Begum; Sakata, Yoichi; Ishizaki, Kimitsune; Yamato, Katsuyuki T; Kohchi, Takayuki; Takezawa, Daisuke

    2010-03-01

    Abscisic acid (ABA) is postulated to be a ubiquitous hormone that plays a central role in seed development and responses to environmental stresses of vascular plants. However, in liverworts (Marchantiophyta), which represent the oldest extant lineage of land plants, the role of ABA has been least emphasized; thus, very little information is available on the molecular mechanisms underlying ABA responses. In this study, we isolated and characterized MpABI1, an ortholog of ABSCISIC ACID INSENSITIVE1 (ABI1), from the liverwort Marchantia polymorpha. The MpABI1 cDNA encoded a 568-amino acid protein consisting of the carboxy-terminal protein phosphatase 2C (PP2C) domain and a novel amino-terminal regulatory domain. The MpABI1 transcript was detected in the gametophyte, and its expression level was increased by exogenous ABA treatment in the gemma, whose growth was strongly inhibited by ABA. Experiments using green fluorescent protein fusion constructs indicated that MpABI1 was mainly localized in the nucleus and that its nuclear localization was directed by the amino-terminal domain. Transient overexpression of MpABI1 in M. polymorpha and Physcomitrella patens cells resulted in suppression of ABA-induced expression of the wheat Em promoter fused to the beta -glucuronidase gene. Transgenic P. patens expressing MpABI1 and its mutant construct, MpABI1-d2, lacking the amino-terminal domain, had reduced freezing and osmotic stress tolerance, and associated with reduced accumulation of ABA-induced late embryogenesis abundant-like boiling-soluble proteins. Furthermore, ABA-induced morphological changes leading to brood cells were not prominent in these transgenic plants. These results suggest that MpABI1 is a negative regulator of ABA signaling, providing unequivocal molecular evidence of PP2C-mediated ABA response mechanisms functioning in liverworts.

  11. [Effect of calcium on medium alkalinization induced by salicylic acid in Salvia miltiorrhiza suspension cultures].

    PubMed

    Liu, Liancheng; Wang, Cong; Dong, Juan'e; Su, Hui; Zhuo, Zequn; Xue, Yaxin

    2013-07-01

    We studied medium alkalinization in Salvia miltiorrhiza suspension cultures treated with salicylic acid and the effect of Ca2+ in this process through application of calcium channel antagonists (Verapamil, LaCl3, LiCl, 2-APB) and ionophore A23187. The results show that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture. Verapamil and LaCl3 or LiCl and 2-APB, two different groups of calcium channel antagonist, significantly inhibited the medium alkalinization induced by salicylic acid. However, the suppression effect of verapamil or LaCl3 on medium alkalinization induced by salicylic acid was higher than that of LiCl or 2-APB. When two types of calcium channel inhibitor (LaCl3 and 2-APB) were used together, the medium alkalinization induced by salicylic acid was completely suppressed and even reduced the pH in medium. On the other hand, A23187 could promote the medium alkalinization. Based on the results above, we speculated that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture, depending on the calcium from both extracell and intracell. Moreover, calcium from extracell plays a more dominant role in this process. Reveal of relationship in this research between Ca2+ and medium alkalinization can provide theory evidence for mechanism of the plant secondary metabolism.

  12. The chromatin remodeler DDM1 promotes hybrid vigor by regulating salicylic acid metabolism.

    PubMed

    Zhang, Qingzhu; Li, Yanqiang; Xu, Tao; Srivastava, Ashish Kumar; Wang, Dong; Zeng, Liang; Yang, Lan; He, Li; Zhang, Heng; Zheng, Zhimin; Yang, Dong-Lei; Zhao, Cheng; Dong, Juan; Gong, Zhizhong; Liu, Renyi; Zhu, Jian-Kang

    2016-01-01

    In plants, hybrid vigor is influenced by genetic and epigenetic mechanisms; however, the molecular pathways are poorly understood. We investigated the potential contributions of epigenetic regulators to heterosis in Arabidposis and found that the chromatin remodeler DECREASED DNA METHYLATION 1 (DDM1) affects early seedling growth heterosis in Col/C24 hybrids. ddm1 mutants showed impaired heterosis and increased expression of non-additively expressed genes related to salicylic acid metabolism. Interestingly, our data suggest that salicylic acid is a hormetic regulator of seedling growth heterosis, and that hybrid vigor arises from crosses that produce optimal salicylic acid levels. Although DNA methylation failed to correlate with differential non-additively expressed gene expression, we uncovered DDM1 as an epigenetic link between salicylic acid metabolism and heterosis, and propose that the endogenous salicylic acid levels of parental plants can be used to predict the heterotic outcome. Salicylic acid protects plants from pathogens and abiotic stress. Thus, our findings suggest that stress-induced hormesis, which has been associated with increased longevity in other organisms, may underlie specific hybrid vigor traits.

  13. The chromatin remodeler DDM1 promotes hybrid vigor by regulating salicylic acid metabolism

    PubMed Central

    Zhang, Qingzhu; Li, Yanqiang; Xu, Tao; Srivastava, Ashish Kumar; Wang, Dong; Zeng, Liang; Yang, Lan; He, Li; Zhang, Heng; Zheng, Zhimin; Yang, Dong-Lei; Zhao, Cheng; Dong, Juan; Gong, Zhizhong; Liu, Renyi; Zhu, Jian-Kang

    2016-01-01

    In plants, hybrid vigor is influenced by genetic and epigenetic mechanisms; however, the molecular pathways are poorly understood. We investigated the potential contributions of epigenetic regulators to heterosis in Arabidposis and found that the chromatin remodeler DECREASED DNA METHYLATION 1 (DDM1) affects early seedling growth heterosis in Col/C24 hybrids. ddm1 mutants showed impaired heterosis and increased expression of non-additively expressed genes related to salicylic acid metabolism. Interestingly, our data suggest that salicylic acid is a hormetic regulator of seedling growth heterosis, and that hybrid vigor arises from crosses that produce optimal salicylic acid levels. Although DNA methylation failed to correlate with differential non-additively expressed gene expression, we uncovered DDM1 as an epigenetic link between salicylic acid metabolism and heterosis, and propose that the endogenous salicylic acid levels of parental plants can be used to predict the heterotic outcome. Salicylic acid protects plants from pathogens and abiotic stress. Thus, our findings suggest that stress-induced hormesis, which has been associated with increased longevity in other organisms, may underlie specific hybrid vigor traits. PMID:27551435

  14. Enhancing tolerance of rice (Oryza sativa) to simulated acid rain by exogenous abscisic acid.

    PubMed

    Wu, Xi; Liang, Chanjuan

    2017-02-01

    Abscisic acid (ABA) regulates much important plant physiological and biochemical processes and induces tolerance to different stresses. Here, we studied the regulation of exogenous ABA on adaptation of rice seedlings to simulated acid rain (SAR) stress by measuring biomass dry weight, stomatal conductance, net photosynthesis rate, nutrient elements, and endogenous hormones. The application of 10 μM ABA alleviated the SAR-induced inhibition on growth, stomatal conductance, net photosynthesis rate, and decreases in contents of nutrient (K, Mg, N, and P) and hormone (auxin, gibberellins, and zeatin). Moreover, 10 μM ABA could stimulate the Ca content as signaling molecules under SAR stress. Contrarily, the application of 100 μM ABA aggravated the SAR-induced inhibition on growth, stomatal conductance, net photosynthesis rate, and contents of nutrient and hormone. The results got after a 5-day recovery (without SAR) show that exogenous 10 μM ABA can promote self-restoration process in rice whereas 100 μM ABA hindered the restoration by increasing deficiency of nutrients and disturbing the balance of hormones. These results confirmed that exogenous ABA at proper concentration could enhance the tolerance of rice to SAR stress.

  15. Comparison the effectiveness of pyruvic acid 50% and salicylic acid 30% in the treatment of acne

    PubMed Central

    Jaffary, Fariba; Faghihi, Gita; Saraeian, Sara; Hosseini, Sayed Mohsen

    2016-01-01

    Background: Acne vulgaris is a chronic inflammatory disease of the pilosebaceous follicles and one of the most common skin diseases. The peeling method has been recently found to be effective for acne treatment. This study aimed to compare the efficacy of pyruvic acid 50% and salicylic acid 30% peeling in the treatment of mild to moderate acne. Materials and Methods: In a prospective single-blinded clinical trial, 86 patients with acne were randomly assigned into two groups. In both groups, the routine treatment of acne (topical solution of erythromycin 4%, triclorocarban soap, and sunscreen) were used twice a day for 8 weeks. In addition, salicylic acid 30% for the control group and pyruvic acid 50% for the case group were used. In both groups, acne severity index (ASI) was calculated before and at week 2, 4, 6, and 8 of the treatment. Patient satisfaction was assessed at the end of the treatment. Side effects were recorded using a checklist. Results: In both groups, the reduction in the number of comedones, papules, and ASI were statistically significant (P < 0.001) in the course of treatment. However, it was not significant regarding the number of pustules (P = 0.09). None of the number of comedone, papules, pustules, and ASI was statistically different between study groups. Both treatment groups had similar side effects except for scaling in the fifth session, which was significantly lower in salicylic acid – treated patients (P = 0.015). Conclusion: Both pyruvic acid 50% and salicylic acid 30% are effective in the improvement of mild to moderate acne with no significant difference in efficacy and side effects. PMID:27904577

  16. Comparison of clindamycin 1% and benzoyl peroxide 5% gel to a novel composition containing salicylic acid, capryloyl salicylic acid, HEPES, glycolic acid, citric acid, and dioic acid in the treatment of acne vulgaris.

    PubMed

    Baumann, Leslie S; Oresajo, Christian; Yatskayer, Margarita; Dahl, Amanda; Figueras, Kristian

    2013-03-01

    This study evaluated the tolerance and efficacy of 2 facial skin products in subjects with acne using the following acne treatments: 1) treatment A, a combination of salicylic acid, capryloyl salicylic acid, HEPES, glycolic acid, citric acid, and dioic acid, and 2) treatment B (BenzaClin®, clindamycin 1% and benzoyl peroxide 5% gel). The treatment design included the split-face application of treatment A and treatment B and the full-face application of the cleanser, moisturizer, and sunscreen. Data were collected through physician visual assessments, subject irritation questionnaires and assessments, along with clinical photography. Results showed similar tolerance and efficacy for both treatments.

  17. Salicylic acid-releasing polyurethane acrylate polymers as anti-biofilm urological catheter coatings.

    PubMed

    Nowatzki, Paul J; Koepsel, Richard R; Stoodley, Paul; Min, Ke; Harper, Alan; Murata, Hironobu; Donfack, Joseph; Hortelano, Edwin R; Ehrlich, Garth D; Russell, Alan J

    2012-05-01

    Biofilm-associated infections are a major complication of implanted and indwelling medical devices like urological and venous catheters. They commonly persist even in the presence of an oral or intravenous antibiotic regimen, often resulting in chronic illness. We have developed a new approach to inhibiting biofilm growth on synthetic materials through controlled release of salicylic acid from a polymeric coating. Herein we report the synthesis and testing of a ultraviolet-cured polyurethane acrylate polymer composed, in part, of salicyl acrylate, which hydrolyzes upon exposure to aqueous conditions, releasing salicylic acid while leaving the polymer backbone intact. The salicylic acid release rate was tuned by adjusting the polymer composition. Anti-biofilm performance of the coatings was assessed under several biofilm forming conditions using a novel combination of the MBEC Assay™ biofilm multi-peg growth system and bioluminescence monitoring for live cell quantification. Films of the salicylic acid-releasing polymers were found to inhibit biofilm formation, as shown by bioluminescent and GFP reporter strains of Pseudomonas aeruginosa and Escherichia coli. Urinary catheters coated on their inner lumens with the salicylic acid-releasing polymer significantly reduced biofilm formation by E. coli for up to 5 days under conditions that simulated physiological urine flow.

  18. AHL-priming functions via oxylipin and salicylic acid

    PubMed Central

    Schenk, Sebastian T.; Schikora, Adam

    2015-01-01

    Collaborative action between the host plant and associated bacteria is crucial for the establishment of an efficient interaction. In bacteria, the synchronized behavior of a population is often achieved by a density-dependent communication called quorum sensing. This behavior is based on signaling molecules, which influence bacterial gene expression. N-acyl homoserine lactones (AHLs) are such molecules in many Gram-negative bacteria. Moreover, some AHLs are responsible for the beneficial effect of bacteria on plants, for example the long chain N-3-oxo-tetradecanoyl-L-homoserine lactone (oxo-C14-HSL) can prime Arabidopsis and barley plants for an enhanced defense. This AHL-induced resistance phenomenon, named AHL-priming, was observed in several independent laboratories during the last two decades. Very recently, the mechanism of priming with oxo-C14-HSL was shown to depend on an oxylipin and salicylic acid (SA). SA is a key element in plant defense, it accumulates during different plant resistance responses and is the base of systemic acquired resistance. In addition, SA itself can prime plants for an enhanced resistance against pathogen attack. On the other side, oxylipins, including jasmonic acid (JA) and related metabolites, are lipid-derived signaling compounds. Especially the oxidized fatty acid derivative cis-OPDA, which is the precursor of JA, is a newly described player in plant defense. Unlike the antagonistic effect of SA and JA in plant–microbe interactions, the recently described pathway functions through a synergistic effect of oxylipins and SA, and is independent of the JA signaling cascade. Interestingly, the oxo-C14-HSL-induced oxylipin/SA signaling pathway induces stomata defense responses and cell wall strengthening thus prevents pathogen invasion. In this review, we summarize the findings on AHL-priming and the related signaling cascade. In addition, we discuss the potential of AHL-induced resistance in new strategies of plant protection. PMID

  19. Perception of the plant immune signal salicylic acid.

    PubMed

    Yan, Shunping; Dong, Xinnian

    2014-08-01

    Salicylic acid (SA) plays a central role in plant innate immunity. The diverse functions of this simple phenolic compound suggest that plants may have multiple SA receptors. Several SA-binding proteins have been identified using biochemical approaches. However, genetic evidence supporting that they are the bona fide SA receptors has not been forthcoming. Mutant screens revealed that NPR1 is a master regulator of SA-mediated responses. Although NPR1 cannot bind SA in a conventional ligand-binding assay, its homologs NPR3 and NPR4 bind SA and function as SA receptors. During pathogen challenge, the SA gradient generated at the infection site is sensed by NPR3 and NPR4, which serve as the adaptors for the Cullin 3-based E3 ubiquitin ligase to regulate NPR1 degradation. Consequently, NPR1 is degraded at the infection site to remove its inhibition on effector-triggered cell death and defense, whereas NPR1 accumulates in neighboring cells to promote cell survival and SA-mediated resistance.

  20. Transcriptome Sequencing in Response to Salicylic Acid in Salvia miltiorrhiza

    PubMed Central

    Zhang, Xiaoru; Dong, Juane; Liu, Hailong; Wang, Jiao; Qi, Yuexin; Liang, Zongsuo

    2016-01-01

    Salvia miltiorrhiza is a traditional Chinese herbal medicine, whose quality and yield are often affected by diseases and environmental stresses during its growing season. Salicylic acid (SA) plays a significant role in plants responding to biotic and abiotic stresses, but the involved regulatory factors and their signaling mechanisms are largely unknown. In order to identify the genes involved in SA signaling, the RNA sequencing (RNA-seq) strategy was employed to evaluate the transcriptional profiles in S. miltiorrhiza cell cultures. A total of 50,778 unigenes were assembled, in which 5,316 unigenes were differentially expressed among 0-, 2-, and 8-h SA induction. The up-regulated genes were mainly involved in stimulus response and multi-organism process. A core set of candidate novel genes coding SA signaling component proteins was identified. Many transcription factors (e.g., WRKY, bHLH and GRAS) and genes involved in hormone signal transduction were differentially expressed in response to SA induction. Detailed analysis revealed that genes associated with defense signaling, such as antioxidant system genes, cytochrome P450s and ATP-binding cassette transporters, were significantly overexpressed, which can be used as genetic tools to investigate disease resistance. Our transcriptome analysis will help understand SA signaling and its mechanism of defense systems in S. miltiorrhiza. PMID:26808150

  1. Salicylic acid attenuates gentamicin-induced nephrotoxicity in rats.

    PubMed

    Randjelovic, Pavle; Veljkovic, Slavimir; Stojiljkovic, Nenad; Jankovic-Velickovic, Ljubinka; Sokolovic, Dusan; Stoiljkovic, Milan; Ilic, Ivan

    2012-01-01

    Gentamicin (GM) is a widely used antibiotic against serious and life-threatening infections, but its usefulness is limited by the development of nephrotoxicity. The present study was designed to determine the protective effect of salicylic acid (SA) in gentamicin-induced nephrotoxicity in rats. Quantitative evaluation of gentamicin-induced structural alterations and degree of functional alterations in the kidneys were performed by histopathological and biochemical analyses in order to determine potential beneficial effects of SA coadministration with gentamicin. Gentamicin was observed to cause a severe nephrotoxicity which was evidenced by an elevation of serum urea and creatinine levels. The significant increases in malondialdehyde (MDA) levels and protein carbonyl groups indicated that GM-induced tissue injury was mediated through oxidative reactions. On the other hand, simultaneous SA administration protected kidney tissue against the oxidative damage and the nephrotoxic effect caused by GM treatment. Exposure to GM caused necrosis of tubular epithelial cells. Necrosis of tubules was found to be prevented by SA pretreatment. The results from our study indicate that SA supplement attenuates oxidative-stress associated renal injury by reducing oxygen free radicals and lipid peroxidation in gentamicin-treated rats.

  2. Salicylic acid enhances Staphylococcus aureus extracellular adhesin protein expression.

    PubMed

    Alvarez, Lucía P; Barbagelata, María S; Cheung, Ambrose L; Sordelli, Daniel O; Buzzola, Fernanda R

    2011-11-01

    One of the virulence factors required by Staphylococcus aureus at the early stages of infection is Eap, a secreted adhesin that binds many host proteins and is upregulated by the two-component regulatory system saeRS. The S. aureus Newman strain harbors a mutation in saeS that is thought to be responsible for the high level of Eap expression in this strain. This study was designed to ascertain whether salicylic acid (SAL) affects the expression of Eap and the internalization of S. aureus into epithelial cells. The strain Newman treated with SAL exhibited increased levels of eap transcription and protein expression. Furthermore, SAL treatment increased the eap promoter activity. SAL treatment enhanced Eap expression in the Newman and in other S. aureus strains that do not carry the mutation in saeS. Internalization of S. aureus eap and sae mutants into the MAC-T epithelial cells was significantly decreased compared with the wild-type counterparts. In conclusion, we demonstrated that a low concentration of SAL increased S. aureus Eap expression possibly due to enhancement of sae. SAL may create the conditions for S. aureus persistence in the host, not only by decreasing the capsular polysaccharide expression as shown before, but also by enhancing Eap expression.

  3. Salicylic acid interferes with GFP fluorescence in vivo.

    PubMed

    de Jonge, Jennifer; Hofius, Daniel; Hennig, Lars

    2017-03-29

    Fluorescent proteins have become essential tools for cell biologists. They are routinely used by plant biologists for protein and promoter fusions to infer protein localization, tissue-specific expression and protein abundance. When studying the effects of biotic stress on chromatin, we unexpectedly observed a decrease in GFP signal intensity upon salicylic acid (SA) treatment in Arabidopsis lines expressing histone H1-GFP fusions. This GFP signal decrease was dependent on SA concentration. The effect was not specific to the linker histone H1-GFP fusion but was also observed for the nucleosomal histone H2A-GFP fusion. This result prompted us to investigate a collection of fusion proteins, which included different promoters, subcellular localizations and fluorophores. In all cases, fluorescence signals declined strongly or disappeared after SA application. No changes were detected in GFP-fusion protein abundance when fluorescence signals were lost indicating that SA does not interfere with protein stability but GFP fluorescence. In vitro experiments showed that SA caused GFP fluorescence reduction only in vivo but not in vitro, suggesting that SA requires cellular components to cause fluorescence reduction. Together, we conclude that SA can interfere with the fluorescence of various GFP-derived reporter constructs in vivo. Assays that measure relocation or turnover of GFP-tagged proteins upon SA treatment should therefore be evaluated with caution.

  4. ATP binding cassette modulators control abscisic acid-regulated slow anion channels in guard cells

    PubMed Central

    Leonhardt, N; Vavasseur, A; Forestier, C

    1999-01-01

    In animal cells, ATP binding cassette (ABC) proteins are a large family of transporters that includes the sulfonylurea receptor and the cystic fibrosis transmembrane conductance regulator (CFTR). These two ABC proteins possess an ion channel activity and bind specific sulfonylureas, such as glibenclamide, but homologs have not been identified in plant cells. We recently have shown that there is an ABC protein in guard cells that is involved in the control of stomatal movements and guard cell outward K+ current. Because the CFTR, a chloride channel, is sensitive to glibenclamide and able to interact with K+ channels, we investigated its presence in guard cells. Potent CFTR inhibitors, such as glibenclamide and diphenylamine-2-carboxylic acid, triggered stomatal opening in darkness. The guard cell protoplast slow anion current that was recorded using the whole-cell patch-clamp technique was inhibited rapidly by glibenclamide in a dose-dependent manner; the concentration producing half-maximum inhibition was at 3 &mgr;M. Potassium channel openers, which bind to and act through the sulfonylurea receptor in animal cells, completely suppressed the stomatal opening induced by glibenclamide and recovered the glibenclamide-inhibited slow anion current. Abscisic acid is known to regulate slow anion channels and in our study was able to relieve glibenclamide inhibition of slow anion current. Moreover, in epidermal strip bioassays, the stomatal closure triggered by Ca2+ or abscisic acid was reversed by glibenclamide. These results suggest that the slow anion channel is an ABC protein or is tightly controlled by such a protein that interacts with the abscisic acid signal transduction pathway in guard cells. PMID:10368184

  5. An ultrahigh-performance liquid chromatography method with electrospray ionization tandem mass spectrometry for simultaneous quantification of five phytohormones in medicinal plant Glycyrrhiza uralensis under abscisic acid stress.

    PubMed

    Xiang, Yu; Song, Xiaona; Qiao, Jing; Zang, Yimei; Li, Yanpeng; Liu, Yong; Liu, Chunsheng

    2015-07-01

    An efficient simplified method was developed to determine multiple classes of phytohormones simultaneously in the medicinal plant Glycyrrhiza uralensis. Ultrahigh-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC/ESI-MS/MS) with multiple reaction monitoring (MRM) in negative mode was used for quantification. The five studied phytohormones are gibberellic acid (GA3), abscisic acid (ABA), jasmonic acid (JA), indole-3-acetic acid, and salicylic acid (SA). Only 100 mg of fresh leaves was needed, with one purification step based on C18 solid-phase extraction. Cinnamic acid was chosen as the internal standard instead of isotope-labeled internal standards. Under the optimized conditions, the five phytohormones with internal standard were separated within 4 min, with good linearities and high sensitivity. The validated method was applied to monitor the spatial and temporal changes of the five phytohormones in G. uralensis under ABA stress. The levels of GA3, ABA, JA, and SA in leaves of G. uralensis were increased at different times and with different tendencies in the reported stress mode. These changes in phytohormone levels are discussed in the context of a possible feedback regulation mechanism. Understanding this mechanism will provide a good chance of revealing the mutual interplay between different biosynthetic routes, which could further help elucidate the mechanisms of effective composition accumulation in medicinal plants.

  6. The Magnesium-Chelatase H Subunit Binds Abscisic Acid and Functions in Abscisic Acid Signaling: New Evidence in Arabidopsis1[W][OA

    PubMed Central

    Wu, Fu-Qing; Xin, Qi; Cao, Zheng; Liu, Zhi-Qiang; Du, Shu-Yuan; Mei, Chao; Zhao, Chen-Xi; Wang, Xiao-Fang; Shang, Yi; Jiang, Tao; Zhang, Xiao-Feng; Yan, Lu; Zhao, Rui; Cui, Zi-Ning; Liu, Rui; Sun, Hai-Li; Yang, Xin-Ling; Su, Zhen; Zhang, Da-Peng

    2009-01-01

    Using a newly developed abscisic acid (ABA)-affinity chromatography technique, we showed that the magnesium-chelatase H subunit ABAR/CHLH (for putative abscisic acid receptor/chelatase H subunit) specifically binds ABA through the C-terminal half but not the N-terminal half. A set of potential agonists/antagonists to ABA, including 2-trans,4-trans-ABA, gibberellin, cytokinin-like regulator 6-benzylaminopurine, auxin indole-3-acetic acid, auxin-like substance naphthalene acetic acid, and jasmonic acid methyl ester, did not bind ABAR/CHLH. A C-terminal C370 truncated ABAR with 369 amino acid residues (631–999) was shown to bind ABA, which may be a core of the ABA-binding domain in the C-terminal half. Consistently, expression of the ABAR/CHLH C-terminal half truncated proteins fused with green fluorescent protein (GFP) in wild-type plants conferred ABA hypersensitivity in all major ABA responses, including seed germination, postgermination growth, and stomatal movement, and the expression of the same truncated proteins fused with GFP in an ABA-insensitive cch mutant of the ABAR/CHLH gene restored the ABA sensitivity of the mutant in all of the ABA responses. However, the effect of expression of the ABAR N-terminal half fused with GFP in the wild-type plants was limited to seedling growth, and the restoring effect of the ABA sensitivity of the cch mutant was limited to seed germination. In addition, we identified two new mutant alleles of ABAR/CHLH from the mutant pool in the Arabidopsis Biological Resource Center via Arabidopsis (Arabidopsis thaliana) Targeting-Induced Local Lesions in Genomes. The abar-2 mutant has a point mutation resulting in the N-terminal Leu-348→Phe, and the abar-3 mutant has a point mutation resulting in the N-terminal Ser-183→Phe. The two mutants show altered ABA-related phenotypes in seed germination and postgermination growth but not in stomatal movement. These findings support the idea that ABAR/CHLH is an ABA receptor and reveal

  7. Radiation- and photo-induced formation of salicylic acid from phenol and CO{sub 2} in aqueous solution

    SciTech Connect

    Krapfenbauer, K.; Getoff, N.

    1996-12-31

    The concentration of CO{sub 2} in the atmosphere is steady increasing because of the combustion of fossil fuels and the industrial pollution. As a result, global warming has occurred. In the present study the formation of the salicylic acid and other products, originating from the carboxylation of phenol is investigated. It has been found that the formation of salicylic acid strongly depend on several experimental conditions: pH of the solution, concentration of phenol and CO{sub 2}, and absorbed dose. The formation of salicylic acid was also studied in the presence of catalysts. Photo-induced carboxylation of phenol to salicylic acid will be also reported. Probable reaction mechanisms for the salicylic acid formation are suggested. Finally, a comparison is made between the well known industrial Kolbe-Schmitt process for salicylic acid production and the aspects of the present new method for CO{sub 2} utilization.

  8. Salicylic acid retention impairs aspirin reactivity in type 2 diabetes.

    PubMed

    Zhang, Haowen; Xie, Hao; Zheng, Xiao; Chai, Yingying; Tang, Zhiyuan; Chen, Hanyu; Li, Feiyan; Christoph, Heier; Chen, Jiandong; Sun, Weixin; Ye, Hui; Wang, Shiguang; Hao, Haiping; Chen, Xiaohu

    2017-01-05

    High on-aspirin platelet reactivity (HAPR) has been associated with compromised aspirin efficacy in patients with diabetes suffering from acute cardiovascular events, but the key mechanisms remain elusive. The objective of this study was to uncover the potential link between pathogenic accumulation of salicylic acid (SA), the major metabolite of aspirin, and HAPR in diabetic state. Aspirin failed to inhibit platelet CD62P expression and thromboxane (TX) B2/6-keto-prostaglandin(PG)F1α ratio in a type 2 diabetes mellitus (T2DM) mice model, particularly in the female, which were unanimously accompanied by significantly higher plasma SA concentrations. Pre-administration with SA increased both platelet CD62P expression and TXB2/6-keto-PGF1α ratio in female T2DM mice, while pretreatment with NaHCO3 caused the opposite effect. On the in vitro human umbilical vein endothelial cells (HUVECs)-platelet interaction assay, SA suppressed inflammation-induced cyclooxygenase-2 upregulation on HUVECs and attenuated their inhibitory effect on platelet aggregation in a dose-dependent manner. The prolonged retention of SA in diabetes may be partially explained by the downregulation of various SA efflux transporters in the kidney and the decreased urine pH. Importantly, in female aspirin non-responsive patients, the trough plasma concentration of SA are markedly increased with T2DM treated with long-term aspirin, and TXB2/6-keto-PGF1α ratio and uric acid level in plasma are positively correlated with SA concentration. Our findings support that the accumulation of SA represents an important factor in causing HAPR in diabetes, and that targeting impaired SA excretion may become a novel intervention strategy to diabetes-associated HAPR.

  9. Aromatic hydroxylation of salicylic acid and aspirin by human cytochromes P450.

    PubMed

    Bojić, Mirza; Sedgeman, Carl A; Nagy, Leslie D; Guengerich, F Peter

    2015-06-20

    Aspirin (acetylsalicylic acid) is a well-known and widely-used analgesic. It is rapidly deacetylated to salicylic acid, which forms two hippuric acids-salicyluric acid and gentisuric acid-and two glucuronides. The oxidation of aspirin and salicylic acid has been reported with human liver microsomes, but data on individual cytochromes P450 involved in oxidation is lacking. In this study we monitored oxidation of these compounds by human liver microsomes and cytochrome P450 (P450) using UPLC with fluorescence detection. Microsomal oxidation of salicylic acid was much faster than aspirin. The two oxidation products were 2,5-dihydroxybenzoic acid (gentisic acid, documented by its UV and mass spectrum) and 2,3-dihydroxybenzoic acid. Formation of neither product was inhibited by desferrioxamine, suggesting a lack of contribution of oxygen radicals under these conditions. Although more liphophilic, aspirin was oxidized less efficiently, primarily to the 2,5-dihydroxy product. Recombinant human P450s 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4 all catalyzed the 5-hydroxylation of salicylic acid. Inhibitor studies with human liver microsomes indicated that all six of the previously mentioned P450s could contribute to both the 5- and 3-hydroxylation of salicylic acid and that P450s 2A6 and 2B6 have contributions to 5-hydroxylation. Inhibitor studies indicated that the major human P450 involved in both 3- and 5-hydroxylation of salicylic acid is P450 2E1.

  10. Abscisic acid and other plant hormones: Methods to visualize distribution and signaling.

    PubMed

    Waadt, Rainer; Hsu, Po-Kai; Schroeder, Julian I

    2015-12-01

    The exploration of plant behavior on a cellular scale in a minimal invasive manner is key to understanding plant adaptations to their environment. Plant hormones regulate multiple aspects of growth and development and mediate environmental responses to ensure a successful life cycle. To monitor the dynamics of plant hormone actions in intact tissue, we need qualitative and quantitative tools with high temporal and spatial resolution. Here, we describe a set of biological instruments (reporters) for the analysis of the distribution and signaling of various plant hormones. Furthermore, we provide examples of their utility for gaining novel insights into plant hormone action with a deeper focus on the drought hormone abscisic acid.

  11. 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.

  12. Anacardic Acid, Salicylic Acid, and Oleic Acid Differentially Alter Cellular Bioenergetic Function in Breast Cancer Cells.

    PubMed

    Radde, Brandie N; Alizadeh-Rad, Negin; Price, Stephanie M; Schultz, David J; Klinge, Carolyn M

    2016-11-01

    Anacardic acid is a dietary and medicinal phytochemical that inhibits breast cancer cell proliferation and uncouples oxidative phosphorylation (OXPHOS) in isolated rat liver mitochondria. Since mitochondrial-targeted anticancer therapy (mitocans) may be useful in breast cancer, we examined the effect of anacardic acid on cellular bioenergetics and OXPHOS pathway proteins in breast cancer cells modeling progression to endocrine-independence: MCF-7 estrogen receptor α (ERα)+ endocrine-sensitive; LCC9 and LY2 ERα+, endocrine-resistant, and MDA-MB-231 triple negative breast cancer (TNBC) cells. At concentrations similar to cell proliferation IC50 s, anacardic acid reduced ATP-linked oxygen consumption rate (OCR), mitochondrial reserve capacity, and coupling efficiency while increasing proton leak, reflecting mitochondrial toxicity which was greater in MCF-7 compared to endocrine-resistant and TNBC cells. These results suggest tolerance in endocrine-resistant and TNBC cells to mitochondrial stress induced by anacardic acid. Since anacardic acid is an alkylated 2-hydroxybenzoic acid, the effects of salicylic acid (SA, 2-hydroxybenzoic acid moiety) and oleic acid (OA, monounsaturated alkyl moiety) were tested. SA inhibited whereas OA stimulated cell viability. In contrast to stimulation of basal OCR by anacardic acid (uncoupling effect), neither SA nor OA altered basal OCR- except OA inhibited basal and ATP-linked OCR, and increased ECAR, in MDA-MB-231 cells. Changes in OXPHOS proteins correlated with changes in OCR. Overall, neither the 2-hydroxybenzoic acid moiety nor the monounsaturated alky moiety of anacardic acid is solely responsible for the observed mitochondria-targeted anticancer activity in breast cancer cells and hence both moieties are required in the same molecule for the observed effects. J. Cell. Biochem. 117: 2521-2532, 2016. © 2016 Wiley Periodicals, Inc.

  13. C2-Domain Abscisic Acid-Related Proteins Mediate the Interaction of PYR/PYL/RCAR Abscisic Acid Receptors with the Plasma Membrane and Regulate Abscisic Acid Sensitivity in Arabidopsis[C][W

    PubMed Central

    Rodriguez, Lesia; Diaz, Maira; Rodrigues, Americo; Izquierdo-Garcia, Ana C.; Peirats-Llobet, Marta; Fernandez, Maria A.; Antoni, Regina; Fernandez, Daniel; Marquez, Jose A.; Mulet, Jose M.; Albert, Armando; Rodriguez, Pedro L.

    2014-01-01

    Membrane-delimited abscisic acid (ABA) signal transduction plays a critical role in early ABA signaling, but the molecular mechanisms linking core signaling components to the plasma membrane are unclear. We show that transient calcium-dependent interactions of PYR/PYL ABA receptors with membranes are mediated through a 10-member family of C2-domain ABA-related (CAR) proteins in Arabidopsis thaliana. Specifically, we found that PYL4 interacted in an ABA-independent manner with CAR1 in both the plasma membrane and nucleus of plant cells. CAR1 belongs to a plant-specific gene family encoding CAR1 to CAR10 proteins, and bimolecular fluorescence complementation and coimmunoprecipitation assays showed that PYL4-CAR1 as well as other PYR/PYL-CAR pairs interacted in plant cells. The crystal structure of CAR4 was solved, which revealed that, in addition to a classical calcium-dependent lipid binding C2 domain, a specific CAR signature is likely responsible for the interaction with PYR/PYL receptors and their recruitment to phospholipid vesicles. This interaction is relevant for PYR/PYL function and ABA signaling, since different car triple mutants affected in CAR1, CAR4, CAR5, and CAR9 genes showed reduced sensitivity to ABA in seedling establishment and root growth assays. In summary, we identified PYR/PYL-interacting partners that mediate a transient Ca2+-dependent interaction with phospholipid vesicles, which affects PYR/PYL subcellular localization and positively regulates ABA signaling. PMID:25465408

  14. C2-domain abscisic acid-related proteins mediate the interaction of PYR/PYL/RCAR abscisic acid receptors with the plasma membrane and regulate abscisic acid sensitivity in Arabidopsis.

    PubMed

    Rodriguez, Lesia; Gonzalez-Guzman, Miguel; Diaz, Maira; Rodrigues, Americo; Izquierdo-Garcia, Ana C; Peirats-Llobet, Marta; Fernandez, Maria A; Antoni, Regina; Fernandez, Daniel; Marquez, Jose A; Mulet, Jose M; Albert, Armando; Rodriguez, Pedro L

    2014-12-01

    Membrane-delimited abscisic acid (ABA) signal transduction plays a critical role in early ABA signaling, but the molecular mechanisms linking core signaling components to the plasma membrane are unclear. We show that transient calcium-dependent interactions of PYR/PYL ABA receptors with membranes are mediated through a 10-member family of C2-domain ABA-related (CAR) proteins in Arabidopsis thaliana. Specifically, we found that PYL4 interacted in an ABA-independent manner with CAR1 in both the plasma membrane and nucleus of plant cells. CAR1 belongs to a plant-specific gene family encoding CAR1 to CAR10 proteins, and bimolecular fluorescence complementation and coimmunoprecipitation assays showed that PYL4-CAR1 as well as other PYR/PYL-CAR pairs interacted in plant cells. The crystal structure of CAR4 was solved, which revealed that, in addition to a classical calcium-dependent lipid binding C2 domain, a specific CAR signature is likely responsible for the interaction with PYR/PYL receptors and their recruitment to phospholipid vesicles. This interaction is relevant for PYR/PYL function and ABA signaling, since different car triple mutants affected in CAR1, CAR4, CAR5, and CAR9 genes showed reduced sensitivity to ABA in seedling establishment and root growth assays. In summary, we identified PYR/PYL-interacting partners that mediate a transient Ca(2+)-dependent interaction with phospholipid vesicles, which affects PYR/PYL subcellular localization and positively regulates ABA signaling.

  15. New approach in the treatment of refractory vitiligo: CO2 laser combined with betamethasone and salicylic acid solution.

    PubMed

    Cunha, Paulo Rowilson; Scabine Pessotti, Nabila; Bonati Mattos, Camila; Salai, Ana Flavia

    2017-01-01

    The aim of this study is to evaluate the use of fractional carbon dioxide laser (CO2 ) with betamethasone and salicylic acid solution in the treatment of patients with refractory vitiligo in hands. Each hand of the patient was randomly assigned to one of two groups: lesion treated with fractional carbon dioxide laser associated with betamethasone and salicylic acid solution administration or lesion treated only with betamethasone and salicylic acid solution. We conclude that combined treatment with fractional carbon dioxide laser and betamethasone associated with salicylic acid solution could effectively and safely be used in the treatment of refractory vitiligo.

  16. Formation of molecular complexes of salicylic acid, acetylsalicylic acid, and methyl salicylate in a mixture of supercritical carbon dioxide with a polar cosolvent

    NASA Astrophysics Data System (ADS)

    Petrenko, V. E.; Antipova, M. L.; Gurina, D. L.; Odintsova, E. G.

    2015-08-01

    The solvate structures formed by salicylic acid, acetylsalicylic acid, and methyl salicylate in supercritical (SC) carbon dioxide with a polar cosolvent (methanol, 0.03 mole fractions) at a density of 0.7 g/cm3 and a temperature of 318 K were studied by the molecular dynamics method. Salicylic and acetylsalicylic acids were found to form highly stable hydrogen-bonded complexes with methanol via the hydrogen atom of the carboxyl group. For methyl salicylate in which the carboxyl hydrogen is substituted by a methyl radical, the formation of stable hydrogen bonds with methanol was not revealed. The contribution of other functional groups of the solute to the interactions with the cosolvent was much smaller. An analysis of correlations between the obtained data and the literature data on the cosolvent effect on the solubility of the compounds in SC CO2 showed that the dissolving ability of SC CO2 with respect to a polar organic substance in the presence of a cosolvent increased only when stable hydrogen-bonded complexes are formed between this substance and the cosolvent.

  17. Water deficit-induced changes in abscisic acid, growth polysomes, and translatable RNA in soybean hypocotyls. [Glycine max L

    SciTech Connect

    Bensen, R.J.; Boyer, J.S.; Mullet, J.E. )

    1988-01-01

    Soybean seedlings (Glycine max L.) were germinated and dark-grown in water-saturated vermiculite for 48 hours, then transferred either to water-saturated vermiculite or to low water potential vermiculite. A decrease in growth rate was detectable within 0.8 hour post-transfer to low water potential vermiculite. A fourfold increase in the abscisic acid content of the elongating region was observed within 0.5 hour. At 24 hours post-transfer, hypocotyl elongation was severely arrested and abscisic acid reached its highest measured level. A comparison of the polyA{sup +} RNA populations isolated at 24 hours post-transfer from the elongating region of water-saturated and low water potential vermiculite-grown seedlings was made by two-dimensional polyacrylamide gel analysis of in vitro translation products. It revealed both increases and decreases in the relative amounts of a number of translation products. Rewatering seedlings grown in low water potential vermiculite at 24 hours post-transfer led to a total recovery in growth rate within 0.5 hour, while abscisic acid in the elongating hypocotyl region required 1 to 2 hours to return to uninduced levels. Application of 1.0 millimolar {+-} abscisic acid to well-watered seedlings resulted in a 48% reduction in hypocotyl growth rate during the first 2 hours after treatment. Plants treated with abscisic acid for 24 hours had a lower polysome content than control plants. However, hypocotyl growth inhibition in abscisic acid-treated seedlings preceded the decline in polysome content.

  18. UDP-glucosyltransferase71c5, a major glucosyltransferase, mediates abscisic acid homeostasis in Arabidopsis.

    PubMed

    Liu, Zhen; Yan, Jin-Ping; Li, De-Kuan; Luo, Qin; Yan, Qiujie; Liu, Zhi-Bin; Ye, Li-Ming; Wang, Jian-Mei; Li, Xu-Feng; Yang, Yi

    2015-04-01

    Abscisic acid (ABA) plays a key role in plant growth and development. The effect of ABA in plants mainly depends on its concentration, which is determined by a balance between biosynthesis and catabolism of ABA. In this study, we characterize a unique UDP-glucosyltransferase (UGT), UGT71C5, which plays an important role in ABA homeostasis by glucosylating ABA to abscisic acid -: glucose ester (GE) in Arabidopsis (Arabidopsis thaliana). Biochemical analyses show that UGT71C5 glucosylates ABA in vitro and in vivo. Mutation of UGT71C5 and down-expression of UGT71C5 in Arabidopsis cause delay in seed germination and enhanced drought tolerance. In contrast, overexpression of UGT71C5 accelerates seed germination and reduces drought tolerance. Determination of the content of ABA and ABA-GE in Arabidopsis revealed that mutation in UGT71C5 and down-expression of UGT71C5 resulted in increased level of ABA and reduced level of ABA-GE, whereas overexpression of UGT71C5 resulted in reduced level of ABA and increased level of ABA-GE. Furthermore, altered levels of ABA in plants lead to changes in transcript abundance of ABA-responsive genes, correlating with the concentration of ABA regulated by UGT71C5 in Arabidopsis. Our work shows that UGT71C5 plays a major role in ABA glucosylation for ABA homeostasis.

  19. Selection and characterization of single stranded DNA aptamers for the hormone abscisic Acid.

    PubMed

    Grozio, Alessia; Gonzalez, Victor M; Millo, Enrico; Sturla, Laura; Vigliarolo, Tiziana; Bagnasco, Luca; Guida, Lucrezia; D'Arrigo, Cristina; De Flora, Antonio; Salis, Annalisa; Martin, Elena M; Bellotti, Marta; Zocchi, Elena

    2013-10-01

    The hormone abscisic acid (ABA) is a small molecule involved in pivotal physiological functions in higher plants. Recently, ABA has been also identified as an endogenous hormone in mammals, regulating different cell functions including inflammatory processes, stem cell expansion, insulin release, and glucose uptake. Aptamers are short, single-stranded (ss) oligonucleotidesable to recognize target molecules with high affinity. The small size of the ABA molecule represented a challenge for aptamer development and the aim of this study was to develop specific anti-ABA DNA aptamers. Biotinylated abscisic acid (bio-ABA) was immobilized on streptavidin-coated magnetic beads. DNA aptamers against bio-ABA were selected with 7 iterative rounds of the systematic evolution of ligands by exponential enrichment method (SELEX), each round comprising incubation of the ABA-binding beads with the ssDNA sequences, DNA elution, electrophoresis, and polymerase chain reaction (PCR) amplification. The PCR product was cloned and sequenced. The binding affinity of several clones was determined using bio-ABA immobilized on streptavidin-coated plates. Aptamer 2 and aptamer 9 showed the highest binding affinity, with dissociation constants values of 0.98 ± 0.14 μM and 0.80 ± 0.07 μM, respectively. Aptamers 2 and 9 were also able to bind free, unmodified ABA and to discriminate between different ABA enantiomers and isomers. Our findings indicate that ssDNA aptamers can selectively bind ABA and could be used for the development of ABA quantitation assays.

  20. Effect of salicylic acid on early life stages of common carp (Cyprinus carpio).

    PubMed

    Zivna, Dana; Sehonova, Pavla; Plhalova, Lucie; Marsalek, Petr; Blahova, Jana; Prokes, Miroslav; Divisova, Lenka; Stancova, Vlasta; Dobsikova, Radka; Tichy, Frantisek; Siroka, Zuzana; Svobodova, Zdenka

    2015-07-01

    Environmental concentrations of pharmaceutical residues are often low; nevertheless, they are designed to have biological effects at low doses. The aim of this study was to assess the effects of salicylic acid on the growth and development of common carp (Cyprinus carpio) early life stages with respect to antioxidant defence enzymes. An embryo-larval toxicity test lasting 34 days was performed according to OECD guidelines 210 (Fish, Early-life Stage Toxicity Test). The tested concentrations were 0.004, 0.04, 0.4, 4 and 20mg/l of salicylic acid. Hatching, early ontogeny, and both morphometric and condition characteristics were significantly influenced by subchronic exposure to salicylic acid. Also, changes in antioxidant enzyme activity and an increase in lipid peroxidation were observed. The LOEC value was found to be 0.004 mg/l salicylic acid. The results of our study confirm the suggestion that subchronic exposure to salicylic acid at environmental concentrations can have significant effects on aquatic vertebrates.

  1. Electrochemical assisted photocatalytic degradation of salicylic acid with highly ordered TiO2 nanotube electrodes

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Zhu, Jinwei; Wang, Ying; Feng, Jiangtao; Yan, Wei; Xu, Hao

    2014-07-01

    To explore the kinetics of photoelectrocatalytic degradation of salicylic acid, one of the important PPCPs, highly ordered TiO2 nanotube arrays (NTs) were prepared by the electrochemical anodization and characterized with scanning electron microscopy and X-ray diffraction techniques. The effect of TiO2 NTs properties, bias potential, initial salicylic acid concentration and solution pH on the degradation efficiency was studied and carefully analyzed. The results revealed that the salicylic acid degradation follows quasi-first order kinetics in the photoelectrocatalytic process, and the fastest decay kinetics was achieved in acidic environment (pH 2). The result was further interpreted through the electrochemical impedance spectroscopy. It is confirmed that the electrochemical assisted photocatalysis is a synergetic approach to combat stable organic substances with improved efficiency.

  2. 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

  3. Controlled Release of Salicylic Acid from Biodegradable Cross-Linked Polyesters.

    PubMed

    Dasgupta, Queeny; Chatterjee, Kaushik; Madras, Giridhar

    2015-09-08

    The purpose of this work was to develop a family of cross-linked poly(xylitol adipate salicylate)s with a wide range of tunable release properties for delivering pharmacologically active salicylic acid. The synthesis parameters and release conditions were varied to modulate polyester properties and to understand the mechanism of release. Varying release rates were obtained upon longer curing (35% in the noncured polymer to 10% in the cured polymer in 7 days). Differential salicylic acid loading led to the synthesis of polymers with variable cross-linking and the release could be tuned (100% release for the lowest loading to 30% in the highest loading). Controlled release was monitored by changing various factors, and the release profiles were dependent on the stoichiometric composition, pH, curing time, and presence of enzyme. The polymer released a combination of salicylic acid and disalicylic acid, and the released products were found to be nontoxic. Minimal hemolysis and platelet activation indicated good blood compatibility. These polymers qualify as "bioactive" and "resorbable" and can, therefore, find applications as immunomodulatory resorbable biomaterials with tunable release properties.

  4. Proteomic investigation of the effect of salicylic acid on Arabidopsis seed germination and establishment of early defense mechanisms.

    PubMed

    Rajjou, Loïc; Belghazi, Maya; Huguet, Romain; Robin, Caroline; Moreau, Adrien; Job, Claudette; Job, Dominique

    2006-07-01

    The influence of salicylic acid (SA) on elicitation of defense mechanisms in Arabidopsis (Arabidopsis thaliana) seeds and seedlings was assessed by physiological measurements combined with global expression profiling (proteomics). Parallel experiments were carried out using the NahG transgenic plants expressing the bacterial gene encoding SA hydroxylase, which cannot accumulate the active form of this plant defense elicitor. SA markedly improved germination under salt stress. Proteomic analyses disclosed a specific accumulation of protein spots regulated by SA as inferred by silver-nitrate staining of two-dimensional gels, detection of carbonylated (oxidized) proteins, and neosynthesized proteins with [35S]-methionine. The combined results revealed several processes potentially affected by SA. This molecule enhanced the reinduction of the late maturation program during early stages of germination, thereby allowing the germinating seeds to reinforce their capacity to mount adaptive responses in environmental water stress. Other processes affected by SA concerned the quality of protein translation, the priming of seed metabolism, the synthesis of antioxidant enzymes, and the mobilization of seed storage proteins. All the observed effects are likely to improve seed vigor. Another aspect revealed by this study concerned the oxidative stress entailed by SA in germinating seeds, as inferred from a characterization of the carbonylated (oxidized) proteome. Finally, the proteomic data revealed a close interplay between abscisic signaling and SA elicitation of seed vigor.

  5. Cytotoxic Activity of Salicylic Acid-Containing Drug Models with Ionic and Covalent Binding.

    PubMed

    Egorova, Ksenia S; Seitkalieva, Marina M; Posvyatenko, Alexandra V; Khrustalev, Victor N; Ananikov, Valentine P

    2015-11-12

    Three different types of drug delivery platforms based on imidazolium ionic liquids (ILs) were synthesized in high preparative yields, namely, the models involving (i) ionic binding of drug and IL; (ii) covalent binding of drug and IL; and (iii) dual binding using both ionic and covalent approaches. Seven ionic liquids containing salicylic acid (SA-ILs) in the cation or/and in the anion were prepared, and their cytotoxicity toward the human cell lines CaCo-2 (colorectal adenocarcinoma) and 3215 LS (normal fibroblasts) was evaluated. Cytotoxicity of SA-ILs was significantly higher than that of conventional imidazolium-based ILs and was comparable to the pure salicylic acid. It is important to note that the obtained SA-ILs dissolved in water more readily than salicylic acid, suggesting benefits of possible usage of traditional nonsoluble active pharmaceutical ingredients in an ionic liquid form.

  6. Differential response of maize catalases to abscisic acid: Vp1 transcriptional activator is not required for abscisic acid-regulated Cat1 expression.

    PubMed Central

    Williamson, J D; Scandalios, J G

    1992-01-01

    In this paper we describe the distinctive responses of the maize catalases to the plant growth regulator abscisic acid (ABA). We analyzed RNA and enzyme accumulation in excised maize embryos and found that each catalase responded differently to exogenously applied ABA. Levels of Cat1 transcript and enzyme activity rapidly increased. In contrast, levels of Cat2 transcript and protein decreased, while Cat3 transcript levels were not affected. In developing kernels of the ABA-deficient/biosynthetic viviparous mutant vp5, lower levels of Cat1 RNA correlated with lower endogenous ABA levels when compared to measured levels in comparably aged wild-type siblings from the same ear. The maize vp1 mutant line is morphologically insensitive to normal endogenous levels of ABA. Analysis of the response of Cat1 to exogenously applied ABA in mutant and wild-type vp1 sibling embryos suggests that, unlike other ABA-responsive genes analyzed to date, the Vp1 gene product is not essential for the ABA-mediated regulation of Cat1. The significance of these responses to ABA in defining the roles of the various CATs in maize is discussed. Images PMID:1388272

  7. Abscisic acid signalling when soil moisture is heterogeneous: decreased photoperiod sap flow from drying roots limits abscisic acid export to the shoots.

    PubMed

    Dodd, Ian C; Egea, Gregorio; Davies, William J

    2008-09-01

    To investigate the contribution of different parts of the root system to total sap flow and leaf xylem abscisic acid (ABA) concentration ([X-ABA](leaf)), individual sunflower (Helianthus annuus L.) shoots were grafted onto the root systems of two plants grown in separate pots and sap flow through each hypocotyl measured below the graft union. During deficit irrigation (DI), both pots received the same irrigation volumes, while during partial root zone drying (PRD) one pot ('wet') was watered and another ('dry') was not. During PRD, once soil water content (theta) decreased below a threshold, the fraction of sap flow from drying roots declined. As theta declined, root xylem ABA concentration increased in both irrigation treatments, and [X-ABA](leaf) increased in DI plants, but [X-ABA](leaf) of PRD plants actually decreased within a certain theta range. A simple model that weighted ABA contributions of wet and dry root systems to [X-ABA](leaf) according to the sap flow from each, better predicted [X-ABA](leaf) of PRD plants than either [X-ABA](dry), [X-ABA](wet) or their mean. Model simulations revealed that [X-ABA](leaf) during PRD exceeded that of DI with moderate soil drying, but continued soil drying (such that sap flow from roots in drying soil ceased) resulted in the opposite effect.

  8. Characterization of Abscisic Acid-Induced Ethylene Production in Citrus Leaf and Tomato Fruit Tissues 1

    PubMed Central

    Riov, Joseph; Dagan, Eliahu; Goren, Raphael; Yang, Shang Fa

    1990-01-01

    Abscisic acid (ABA) significantly stimulated ethylene production in citrus (Citrus sinensis [L.] Osbeck, cv Shamouti orange) leaf discs. The extent of stimulation was dependent upon the concentration of ABA (0.1-1 milimolar) and the duration of treatment (15-300 minutes). Aging the discs before applying ABA increased ABA-induced ethylene production due to enhancement of both ethylene-forming enzyme activity and the responsiveness of ABA. Discs excised from mature leaves were much more responsive to ABA than discs excised from young or senescing leaves. ABA stimulated ethylene production shortly after application, suggesting that ABA does not enhance ethylene production via the acceleration of senescence. The stimulating effect of ABA on ethylene production resulted mainly from the enhancement of 1-aminocylopropane-1-carboxylic acid synthesis. Stimulation of ethylene production by ABA in intact citrus leaves and tomato (Lycopersicon esculentum Mill., cv Castlemart) fruit was small but could be increased by various forms of wounding. PMID:16667264

  9. Solid-state 17O NMR of pharmaceutical compounds: salicylic acid and aspirin.

    PubMed

    Kong, Xianqi; Shan, Melissa; Terskikh, Victor; Hung, Ivan; Gan, Zhehong; Wu, Gang

    2013-08-22

    We report solid-state NMR characterization of the (17)O quadrupole coupling (QC) and chemical shift (CS) tensors in five site-specifically (17)O-labeled samples of salicylic acid and o-acetylsalicylic acid (Aspirin). High-quality (17)O NMR spectra were obtained for these important pharmaceutical compounds under both static and magic angle spinning (MAS) conditions at two magnetic fields, 14.0 and 21.1 T. A total of 14 (17)O QC and CS tensors were experimentally determined for the seven oxygen sites in salicylic acid and Aspirin. Although both salicylic acid and Aspirin form hydrogen bonded cyclic dimers in the solid state, we found that the potential curves for the concerted double proton transfer in these two compounds are significantly different. In particular, while the double-well potential curve in Aspirin is nearly symmetrical, it is highly asymmetrical in salicylic acid. This difference results in quite different temperature dependencies in (17)O MAS spectra of the two compounds. A careful analysis of variable-temperature (17)O MAS NMR spectra of Aspirin allowed us to obtain the energy asymmetry (ΔE) of the double-well potential, ΔE = 3.0 ± 0.5 kJ/mol. We were also able to determine a lower limit of ΔE for salicylic acid, ΔE > 10 kJ/mol. These asymmetrical features in potential energy curves were confirmed by plane-wave DFT computations, which yielded ΔE = 3.7 and 17.8 kJ/mol for Aspirin and salicylic acid, respectively. To complement the solid-state (17)O NMR data, we also obtained solid-state (1)H and (13)C NMR spectra for salicylic acid and Aspirin. Using experimental NMR parameters obtained for all magnetic nuclei present in salicylic acid and Aspirin, we found that plane-wave DFT computations can produce highly accurate NMR parameters in well-defined crystalline organic compounds.

  10. Salicylic Acid-Based Polymers for Guided Bone Regeneration Using Bone Morphogenetic Protein-2

    PubMed Central

    Subramanian, Sangeeta; Mitchell, Ashley; Yu, Weiling; Snyder, Sabrina; Uhrich, Kathryn

    2015-01-01

    Bone morphogenetic protein-2 (BMP-2) is used clinically to promote spinal fusion, treat complex tibia fractures, and to promote bone formation in craniomaxillofacial surgery. Excessive bone formation at sites where BMP-2 has been applied is an established complication and one that could be corrected by guided tissue regeneration methods. In this study, anti-inflammatory polymers containing salicylic acid [salicylic acid-based poly(anhydride-ester), SAPAE] were electrospun with polycaprolactone (PCL) to create thin flexible matrices for use as guided bone regeneration membranes. SAPAE polymers hydrolyze to release salicylic acid, which is a nonsteroidal anti-inflammatory drug. PCL was used to enhance the mechanical integrity of the matrices. Two different SAPAE-containing membranes were produced and compared: fast-degrading (FD-SAPAE) and slow-degrading (SD-SAPAE) membranes that release salicylic acid at a faster and slower rate, respectively. Rat femur defects were treated with BMP-2 and wrapped with FD-SAPAE, SD-SAPAE, or PCL membrane or were left unwrapped. The effects of different membranes on bone formation within and outside of the femur defects were measured by histomorphometry and microcomputed tomography. Bone formation within the defect was not affected by membrane wrapping at BMP-2 doses of 12 μg or more. In contrast, the FD-SAPAE membrane significantly reduced bone formation outside the defect compared with all other treatments. The rapid release of salicylic acid from the FD-SAPAE membrane suggests that localized salicylic acid treatment during the first few days of BMP-2 treatment can limit ectopic bone formation. The data support development of SAPAE polymer membranes for guided bone regeneration applications as well as barriers to excessive bone formation. PMID:25813520

  11. Salicylic Acid-Based Polymers for Guided Bone Regeneration Using Bone Morphogenetic Protein-2.

    PubMed

    Subramanian, Sangeeta; Mitchell, Ashley; Yu, Weiling; Snyder, Sabrina; Uhrich, Kathryn; O'Connor, J Patrick

    2015-07-01

    Bone morphogenetic protein-2 (BMP-2) is used clinically to promote spinal fusion, treat complex tibia fractures, and to promote bone formation in craniomaxillofacial surgery. Excessive bone formation at sites where BMP-2 has been applied is an established complication and one that could be corrected by guided tissue regeneration methods. In this study, anti-inflammatory polymers containing salicylic acid [salicylic acid-based poly(anhydride-ester), SAPAE] were electrospun with polycaprolactone (PCL) to create thin flexible matrices for use as guided bone regeneration membranes. SAPAE polymers hydrolyze to release salicylic acid, which is a nonsteroidal anti-inflammatory drug. PCL was used to enhance the mechanical integrity of the matrices. Two different SAPAE-containing membranes were produced and compared: fast-degrading (FD-SAPAE) and slow-degrading (SD-SAPAE) membranes that release salicylic acid at a faster and slower rate, respectively. Rat femur defects were treated with BMP-2 and wrapped with FD-SAPAE, SD-SAPAE, or PCL membrane or were left unwrapped. The effects of different membranes on bone formation within and outside of the femur defects were measured by histomorphometry and microcomputed tomography. Bone formation within the defect was not affected by membrane wrapping at BMP-2 doses of 12 μg or more. In contrast, the FD-SAPAE membrane significantly reduced bone formation outside the defect compared with all other treatments. The rapid release of salicylic acid from the FD-SAPAE membrane suggests that localized salicylic acid treatment during the first few days of BMP-2 treatment can limit ectopic bone formation. The data support development of SAPAE polymer membranes for guided bone regeneration applications as well as barriers to excessive bone formation.

  12. Salicylic acid sans aspirin in animals and man: persistence in fasting and biosynthesis from benzoic acid.

    PubMed

    Paterson, John R; Baxter, Gwendoline; Dreyer, Jacob S; Halket, John M; Flynn, Robert; Lawrence, James R

    2008-12-24

    Salicylic acid (SA), which is central to defense mechanisms in plants and the principal metabolite of aspirin, occurs naturally in man with higher levels of SA and its urinary metabolite salicyluric acid (SU) in vegetarians overlapping with levels in patients on low-dose aspirin regimens. SA is widely distributed in animal blood. Fasting for major colorectal surgery did not cause disappearance of SA from plasma, even in patients following total proctocolectomy. A (13)C(6) benzoic acid load ingested by six volunteers led, between 8 and 16 h, to a median 33.9% labeling of urinary salicyluric acid. The overall contribution of benzoic acid (and its salts) to the turnover of circulating SA thus requires further assessment. However, that SA appears to be, at least partially, an endogenous compound should lead to reassessment of its role in human (and animal) pathophysiology.

  13. Ascorbic acid and salicylic acid mitigate nacl stress in Caralluma tuberculata Calli.

    PubMed

    Rehman, Riaz Ur; Zia, Muhammad; Abbasi, Bilal Haider; Lu, Gang; Chaudhary, Muhammad Fayyaz

    2014-06-01

    Plants exposed to salt stress undergo biochemical and morphological changes even at cellular level. Such changes also include activation of antioxidant enzymes to scavenge reactive oxygen species, while morphological changes are determined as deformation of membranes and organelles. Present investigation substantiates this phenomenon for Caralluma tuberculata calli when exposed to NaCl stress at different concentrations. Elevated levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) in NaCl-stressed calli dwindled upon application of non-enzymatic antioxidants; ascorbic acid (AA) and salicylic acid (SA). Many fold increased enzymes concentrations trimmed down even below as present in the control calli. Electron microscopic images accentuated several cellular changes upon NaCl stress such as plasmolysed plasma membrane, disruption of nuclear membrane, increased numbers of nucleoli, alteration in shape and lamellar membrane system in plastid, and increased number of plastoglobuli. The cells retrieved their normal structure upon exposure to non-enzymatic antioxidants. The results of the present experiments conclude that NaCl aggravate oxidative molecules that eventually alleviate antioxidant enzymatic system. Furthermore, the salt stress knocked down by applying ascorbic acid and salicylic acid manifested by normal enzyme level and restoration of cellular structure.

  14. Effects of norflurazon, an inhibitor of carotenogenesis, on abscisic acid and xanthoxin in the caps of gravistimulated maize roots

    NASA Technical Reports Server (NTRS)

    Feldman, L. J.; Sun, P. S.

    1986-01-01

    Maize seeds were germinated in the dark in the presence of the carotenoid synthesis inhibitor norflurazon and the levels of abscisic acid, xanthoxin and total carotenoids were measured in the root cap and in the adjacent 1.5 mm segment. In norflurazon-treated roots abscisic acid levels were markedly reduced, but an increase occurred in the levels of xanthoxin, a compound structurally and physiologically similar to abscisic acid. In the cultivar of maize (Zea mays L. cv. Merit) used for this work, brief illumination of the root is required for gravitropic curving. Following illumination both control and norflurazon-treated roots showed normal gravitropic curvature; however, the rate of curvature was delayed in norflurazon-treated roots. Our data from norflurazon-treated roots are consistent with a role for xanthoxin in maize root gravitropism. The increase in xanthoxin in the presence of an inhibitor of carotenoid synthesis suggests that xanthoxin and abscisic acid originate, at least in part, via different metabolic pathways.

  15. Genetic Association Mapping Identifies Single Nucleotide Polymorphisms in Genes that Affect Abscisic Acid Levels in Maize Floral Tissues During Drought

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In maize, development of the female inflorescence and its floral parts is vulnerable to water stress at flowering, which causes loss of kernel set and productivity. While changes in the levels of sugars and abscisic acid (ABA) are thought to play a role in this stress response, the mechanistic basi...

  16. Overexpression of cotton GhMKK4 enhances disease susceptibility and affects abscisic acid, gibberellin and hydrogen peroxide signalling in transgenic Nicotiana benthamiana.

    PubMed

    Li, Yuzhen; Zhang, Liang; Lu, Wenjing; Wang, Xiuling; Wu, Chang-Ai; Guo, Xingqi

    2014-01-01

    Mitogen-activated protein kinase (MAPK) cascades are involved in plant development, stress responses and hormonal signal transduction. MAPK kinases (MAPKKs), as the key nodes in these cascades, link MAPKs and MAPKK kinases (MAPKKKs). In this study, GhMKK4, a novel group C MAPKK gene from cotton (Gossypium hirsutum), was isolated and identified. Its expression can be induced by various stresses and signalling molecules. The overexpression of GhMKK4 in Nicotiana benthamiana enhanced its susceptibility to bacterial and fungal pathogens, but had no significant effects on salt or drought tolerance. Notably, the overexpressing plants showed increased sensitivity to abscisic acid (ABA) and gibberellin A3 (GA3), and ABA and gibberellin (GA) signalling were affected on infection with Ralstonia solanacearum bacteria. Furthermore, the overexpressing plants showed more reactive oxygen species (ROS) accumulation and stronger inhibition of catalase (CAT), a ROS-scavenging enzyme, than control plants after salicylic acid (SA) treatment. Interestingly, two genes encoding ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC), the key enzymes in polyamine synthesis, exhibited reduced R. solanacearum-induced expression in overexpressing plants. These findings broaden our knowledge about the functions of MAPKKs in diverse signalling pathways and the negative regulation of disease resistance in the cotton crop.

  17. Glutathione and abscisic acid supplementation influences somatic embryo maturation and hormone endogenous levels during somatic embryogenesis in Podocarpus lambertii Klotzsch ex Endl.

    PubMed

    Fraga, Hugo Pacheco de Freitas; Vieira, Leila do Nascimento; Puttkammer, Catarina Corrêa; Dos Santos, Henrique Pessoa; Garighan, Julio de Andrade; Guerra, Miguel Pedro

    2016-12-01

    Here we propose a protocol for embryogenic cultures induction, proliferation and maturation for the Brazilian conifer Podocarpus lambertii, and investigated the effect of abscisic acid (ABA) and glutathione (GSH) supplementation on the maturation phase. ABA, zeatin (Z) and salicylic acid (SA) endogenous levels were quantified. Number of somatic embryos obtained in ABA-supplemented treatment was significant higher than in ABA-free treatment, showing the relevance of ABA supplementation during somatic embryos maturation. Histological analysis showed the stereotyped sequence of developmental stages in conifer somatic embryos, reaching the late torpedo-staged embryo. GSH supplementation in maturation culture medium improved the somatic embryos number and morphological features. GSH 0mM and GSH 0.1mM treatments correlated with a decreased ABA endogenous level during maturation, while GSH 0.5mM treatment showed constant levels. All treatments resulted in decreased Z endogenous levels, supporting the concept that cytokinins are important during the initial cell division but not for the later stages of embryo development. The lowest SA levels found in GSH 0.5mM treatment were coincident with early embryonic development, and this treatment resulted in the highest development of somatic embryos. Thus, a correlation between lower SA levels and improved somatic embryo formation can be hypothesized.

  18. Incorporation of salicylic acid derivatives to hydrophilic copolymer systems with biomedical applications.

    PubMed

    Elvira, C; Gallardo, A; Lacroix, N; Schacht, E; San Román, J

    2001-06-01

    Hydrogels based on polymeric derivatives of salicylic acid have been prepared for biomedical applications by free radical copolymerization of 2-hydroxy-4-methacrylamidobenzoic acid, 4HMA, and 2-hydroxy-5-methacrylamidobenzoic acid, 5HMA, with 2- hydroxyethylmethacrylate, HEMA, in a wide range of compositions. The reactivity ratios of 4HMA and 5HMA with HEMA in radical copolymerization processes have been determined from their 1H NMR spectra by applying linearization methods and non-linear least square treatments. Tgs of the corresponding copolymers were analyzed by DSC. The swelling behavior in water of the prepared copolymers was studied in comparison to poly-(HEMA), poly-(4HMA) and poly-(5HMA) hydration degrees, being in all cases superior to 35%. The hydrolytical behavior of the synthesized copolymers was studied at three different pHs (2, 7.4 and 10) determining the release percentage of the salicylic acid derivatives, 4-amino salicylic acid, 4ASA, and 5-amino salicylic acid, 5ASA, analyzed by high performance liquid chromatography (HPLC). The release analysis was followed during 230 days and a pH dependence was observed obtaining the highest release percentages at pH=10, whereas at physiological pH (7.4) the release percentages were in range from 2 to 5% at that time for all copolymer systems. The hydrolytical stability is enough for long-term applications like bone cements, ionomers, etc.

  19. Effects of mixing procedure itself on the structure, viscosity, and spreadability of white petrolatum and salicylic acid ointment and the skin permeation of salicylic acid.

    PubMed

    Kitagawa, Shuji; Fujiwara, Megumi; Okinaka, Yuta; Yutani, Reiko; Teraoka, Reiko

    2015-01-01

    White petrolatum is a mixture of solid and liquid hydrocarbons and its structure can be affected by shear stress. Thus, it might also induce changes in its rheological properties. In this study, we used polarization microscopy to investigate how different mixing methods affect the structure of white petrolatum. We used two different mixing methods, mixing using a rotation/revolution mixer and mixing using an ointment slab and an ointment spatula. The extent of the fragmentation and dispersal of the solid portion of white petrolatum depended on the mixing conditions. Next, we examined the changes in the structure of a salicylic acid ointment, in which white petrolatum was used as a base, induced by mixing and found that the salicylic acid solids within the ointment were also dispersed. In addition to these structural changes, the viscosity and thixotropic behavior of both test substances also decreased in a mixing condition-dependent manner. The reductions in these parameters were most marked after mixing with a rotation/revolution mixer, and similar results were obtained for spreadability. We also investigated the effects of mixing procedure on the skin accumulation and permeation of salicylic acid. They were increased by approximately three-fold after mixing. Little difference in skin accumulation or permeation was detected between the two mixing methods. These findings indicate that mixing procedures themselves affect the utility and physiological effects of white petrolatum-based ointments. Therefore, these effects should be considered when mixing is required for the clinical use of petrolatum-based ointments.

  20. Antitranspirant associated abscisic Acid effects on the water relations and yield of transplanted bell peppers.

    PubMed

    Berkowitz, G A; Rabin, J

    1988-02-01

    Greenhouse and field experiments were performed to determine if increased leaf resistance induced by exogenous application of abscisic acid (ABA) could enhance the water status of transplanted bell pepper seedlings. Seedling survival and yield were also monitored in the field experiment. When seedlings were transplanted into either wet or dry potting mix in the greenhouse, ABA increased leaf resistance and leaf water potential. In the field, plots were irrigated either immediately after, or 1 day after transplanting. Under both treatments, ABA application resulted in increased leaf resistance and water potential, but seedling survival and yield were enhanced due to ABA only in plots which were irrigated 1 day after transplanting. It is concluded that antitranspirant application can reduce transplant shock and increase yield of bell pepper.

  1. Postharvest Exogenous Application of Abscisic Acid Reduces Internal Browning in Pineapple.

    PubMed

    Zhang, Qin; Liu, Yulong; He, Congcong; Zhu, Shijiang

    2015-06-10

    Internal browning (IB) is a postharvest physiological disorder causing economic losses in pineapple, but there is no effective control measure. In this study, postharvest application of 380 μM abscisic acid (ABA) reduced IB incidence by 23.4-86.3% and maintained quality in pineapple fruit. ABA reduced phenolic contents and polyphenol oxidase and phenylalanine ammonia lyase activities; increased catalase and peroxidase activities; and decreased O2(·-), H2O2, and malondialdehyde levels. This suggests ABA could control IB through inhibiting phenolics biosynthesis and oxidation and enhancing antioxidant capability. Furthermore, the efficacy of IB control by ABA was not obviously affected by tungstate, ABA biosynthesis inhibitor, nor by diphenylene iodonium, NADPH oxidase inhibitor, nor by lanthanum chloride, calcium channel blocker, suggesting that ABA is sufficient for controlling IB. This process might not involve H2O2 generation, but could involve the Ca(2+) channels activation. These results provide potential for developing effective measures for controlling IB in pineapple.

  2. Developmental priming of stomatal sensitivity to abscisic acid by leaf microclimate.

    PubMed

    Pantin, Florent; Renaud, Jeanne; Barbier, François; Vavasseur, Alain; Le Thiec, Didier; Rose, Christophe; Bariac, Thierry; Casson, Stuart; McLachlan, Deirdre H; Hetherington, Alistair M; Muller, Bertrand; Simonneau, Thierry

    2013-09-23

    Plant water loss and CO2 uptake are controlled by valve-like structures on the leaf surface known as stomata. Stomatal aperture is regulated by hormonal and environmental signals. We show here that stomatal sensitivity to the drought hormone abscisic acid (ABA) is acquired during leaf development by exposure to an increasingly dryer atmosphere in the rosette plant Arabidopsis. Young leaves, which develop in the center of the rosette, do not close in response to ABA. As the leaves increase in size, they are naturally exposed to increasingly dry air as a consequence of the spatial arrangement of the leaves, and this triggers the acquisition of ABA sensitivity. Interestingly, stomatal ABA sensitivity in young leaves is rapidly restored upon water stress. These findings shed new light on how plant architecture and stomatal physiology have coevolved to optimize carbon gain against water loss in stressing environments.

  3. Movement of abscisic acid into the apoplast in response to water stress in Xanthium strumarium L

    SciTech Connect

    Cornish, K.; Zeevaart, J.A.D.

    1985-07-01

    The effect of water stress on the redistribution of abscisic acid (ABA) in mature leaves of Xanthium strumarium L. was investigated using a pressure dehydration technique. In both turgid and stressed leaves, the ABA in the xylem exudate, the apoplastic ABA, increased before bulk leaf stress-induced ABA accumulation began. In the initially turgid leaves, the ABA level remained constant in both the apoplast and the leaf as a whole until wilting symptoms appeared. Following turgor loss, sufficient quantities of ABA moved into the apoplast to stimulate stomatal closure. Thus, the initial increase of apoplastic ABA may be relevant to the rapid stomatal closure seen in stressed leaves before their bulk leaf ABA levels rise. Following recovery from water stress, elevated levels of ABA remained in the apoplast after the bulk leaf contents had returned to their prestress values. This apoplastic ABA may retard stomatal reopening during the initial recovery period. 32 references, 5 figures.

  4. Regulators of PP2C phosphatase activity function as abscisic acid sensors.

    PubMed

    Ma, Yue; Szostkiewicz, Izabela; Korte, Arthur; Moes, Danièle; Yang, Yi; Christmann, Alexander; Grill, Erwin

    2009-05-22

    The plant hormone abscisic acid (ABA) acts as a developmental signal and as an integrator of environmental cues such as drought and cold. Key players in ABA signal transduction include the type 2C protein phosphatases (PP2Cs) ABI1 and ABI2, which act by negatively regulating ABA responses. In this study, we identify interactors of ABI1 and ABI2 which we have named regulatory components of ABA receptor (RCARs). In Arabidopsis, RCARs belong to a family with 14 members that share structural similarity with class 10 pathogen-related proteins. RCAR1 was shown to bind ABA, to mediate ABA-dependent inactivation of ABI1 or ABI2 in vitro, and to antagonize PP2C action in planta. Other RCARs also mediated ABA-dependent regulation of ABI1 and ABI2, consistent with a combinatorial assembly of receptor complexes.

  5. Mechanistic Basis for Plant Responses to Drought Stress : Regulatory Mechanism of Abscisic Acid Signaling

    NASA Astrophysics Data System (ADS)

    Miyakawa, Takuya; Tanokura, Masaru

    The phytohormone abscisic acid (ABA) plays a key role in the rapid adaptation of plants to environmental stresses such as drought and high salinity. Accumulated ABA in plant cells promotes stomatal closure in guard cells and transcription of stress-tolerant genes. Our understanding of ABA responses dramatically improved by the discovery of both PYR/PYL/RCAR as a soluble ABA receptor and inhibitory complex of a protein phospatase PP2C and a protein kinase SnRK2. Moreover, several structural analyses of PYR/PYL/RCAR revealed the mechanistic basis for the regulatory mechanism of ABA signaling, which provides a rational framework for the design of alternative agonists in future.

  6. Emerging roles of protein kinase CK2 in abscisic acid signaling

    PubMed Central

    Vilela, Belmiro; Pagès, Montserrat; Riera, Marta

    2015-01-01

    The phytohormone abscisic acid (ABA) regulates many aspects of plant growth and development as well as responses to multiple stresses. Post-translational modifications such as phosphorylation or ubiquitination have pivotal roles in the regulation of ABA signaling. In addition to the positive regulator sucrose non-fermenting-1 related protein kinase 2 (SnRK2), the relevance of the role of other protein kinases, such as CK2, has been recently highlighted. We have recently established that CK2 phosphorylates the maize ortholog of open stomata 1 OST1, ZmOST1, suggesting a role of CK2 phosphorylation in the control of ZmOST1 protein degradation (Vilela et al., 2015). CK2 is a pleiotropic enzyme involved in multiple developmental and stress-responsive pathways. This review summarizes recent advances that taken together suggest a prominent role of protein kinase CK2 in ABA signaling and related processes. PMID:26579189

  7. The abscisic acid induction of a novel peroxidase is antagonized by cytokinin in Spirodela polyrrhiza L.

    PubMed Central

    Chaloupková, K; Smart, C C

    1994-01-01

    The growth regulator abscisic acid (ABA) can be used to induce dormant bud structures (turions) in the duckweed Spirodela polyrrhiza L. In this paper we show that during this process, ABA rapidly induces elevated levels of mRNA transcripts encoding a novel basic peroxidase. In addition, we show that in the presence of the cytokinin kinetin the maintained increase is attenuated. Kinetin not only totally inhibits the induction of turions by ABA but also alleviates ABA-induced growth inhibition. This antagonism of an ABA-induced gene by a cytokinin correlates with an easily observable antagonistic effect of these two hormones on plant morphogenesis. These data contribute to a growing body of evidence linking growth regulators with changes in peroxidase gene expression and to the concept of pairs of hormones playing antagonistic roles during plant development. Finally, we discuss the possible functions that peroxidases could have during ABA-induced turion formation and growth inhibition. PMID:8066130

  8. G-protein coupling and nuclear translocation of the human abscisic acid receptor LANCL2

    PubMed Central

    Fresia, Chiara; Vigliarolo, Tiziana; Guida, Lucrezia; Booz, Valeria; Bruzzone, Santina; Sturla, Laura; Di Bona, Melody; Pesce, Mattia; Usai, Cesare; De Flora, Antonio; Zocchi, Elena

    2016-01-01

    Abscisic acid (ABA), a long known phytohormone, has been recently demonstrated to be present also in humans, where it targets cells of the innate immune response, mesenchymal and hemopoietic stem cells and cells involved in the regulation of systemic glucose homeostasis. LANCL2, a peripheral membrane protein, is the mammalian ABA receptor. We show that N-terminal glycine myristoylation causes LANCL2 localization to the plasmamembrane and to cytoplasmic membrane vesicles, where it interacts with the α subunit of a Gi protein and starts the ABA signaling pathway via activation of adenylate cyclase. Demyristoylation of LANCL2 by chemical or genetic means triggers its nuclear translocation. Nuclear enrichment of native LANCL2 is also induced by ABA treatment. Therefore human LANCL2 is a non-transmembrane G protein-coupled receptor susceptible to hormone-induced nuclear translocation. PMID:27222287

  9. Effect of abscisic acid and hydrogen peroxide on antioxidant enzymes in Syzygium cumini plant.

    PubMed

    Choudhary, Ramkishan; Saroha, Ajaya Eesha; Swarnkar, P L

    2012-10-01

    The present study was undertaken to study the effect of abscisic acid and hydrogen peroxide on the activities of antioxidant enzymes namely superoxide dismutase (SOD; E.C. 1.15.1.1), catalase (CAT; E.C. 1.11.1.6) and ascorbate peroxidase (APX; E.C. 1.11.1.11) in Syzygium cumini plant. The varying concentrations of ABA (2-8 mM/l) and H2O2 (2-8 mM/l) modulated enzyme activities differently. In general, some concentrations of the ABA and H2O2 stimulated the activities of all the three enzymes except that there was a dose dependent reduction in catalase activity in the plants treated with ABA.

  10. Abscisic Acid Elicits the Water-Stress Response in Root Hairs of Arabidopsis thaliana1

    PubMed Central

    Schnall, Jennifer A.; Quatrano, Ralph S.

    1992-01-01

    Water stress has been shown to cause root hairs to become short and bulbous. Because abscisic acid (ABA) mediates a variety of water-stress responses, we investigated the response of Arabidopsis thaliana root hairs to ABA. When wild-type root hairs were treated with ABA, they exhibited the water-stress response. The Arabidopsis mutants abi1 and abi2, which are insensitive to ABA at the seedling stage, did not display the root hair response. These data suggest that ABA may mediate the response of root hairs to water stress. The drought response of root hairs resulting in an inhibition of tip growth will provide an easy screen to select mutations that are insensitive to ABA and/or involved in tip growth. Images Figure 1 PMID:16652949

  11. Polymeric prodrug-functionalized polypropylene films for sustained release of salicylic acid.

    PubMed

    Magaña, Hector; Palomino, Kenia; Cornejo-Bravo, Jose M; Díaz-Gómez, Luis; Concheiro, Angel; Zavala-Lagunes, Edgar; Alvarez-Lorenzo, Carmen; Bucio, Emilio

    2016-09-10

    Medical devices decorated with salicylic acid-based polymer chains (polymeric prodrug) that slowly release this anti-inflammatory and anti-biofilm drug at the implantation site were designed. A "grafting from" method was implemented to directly grow chains of a polymerizable derivative of salicylic acid (2-methacryloyloxy-benzoic acid, 2MBA) onto polypropylene (PP). PP was modified both at bulk and on the surface with poly(2MBA) by means of an oxidative pre-irradiation method ((60)Co source), in order to obtain a grafted polymer in which salicylic acid units were linked by means of labile ester bonds. The grafting percent depended on absorbed dose, reaction time, temperature and monomer concentration. The functionalized films were analyzed regarding structure (FTIR-ATR, SEM-EDX, fluorescence microscopy), temperature stability (TGA), interaction with aqueous medium (water contact angle and swelling), pH-responsive release and cytocompatibility (fibroblasts). In the obtained poly(2MBA)-grafted biomaterial, poly(2MBA) behaved as a polymeric prodrug that regulates salicylic acid release once in contact with aqueous medium, showing pH-dependent release rate.

  12. Salicylic Acid Treatment Increases the Levels of Triterpene Glycosides in Black Cohosh (Actaea Racemosa) Rhizomes.

    PubMed

    De Capite, Annette; Lancaster, Tyler; Puthoff, David

    2016-01-01

    Black cohosh (Actaea racemosa) serves as the host plant for the Appalachian azure butterfly, Celastrina neglectamajor. Overharvesting of Black cohosh for the dietary supplement industry may result in its extirpation, and may also cause the elimination of the dependent butterfly. One way to increase or maintain the number of host plants in forested environments would be to reduce the number harvested, for example by increasing the levels of the desired metabolites in Black cohosh rhizomes. The secondary metabolites actein and deoxyactein are triterpene glycosides and are among the compounds associated with the putative activity of Black cohosh extracts. Acetein and deoxyacetein are used to standardize Black cohosh supplements. To gain an understanding of mechanisms that may control actein and deoxyactein accumulation, Black cohosh rhizomes were treated with exogenous salicylic acid, jasmonic acid, or ethylene, or were mechanically wounded. Salicylic acid treatment significantly increased the levels of actein and deoxyactein in the rhizome of Black cohosh, suggesting that the synthesis of triterpene glycosides is controlled in part by salicylic acid. Using salicylic acid or related chemicals to increase the levels of actein and deoxyactein in rhizomes may help supply the supplement industry and, simultaneously, help conserve Black cohosh and species dependent upon it.

  13. Dynamics of Responses in Compatible Potato - Potato virus Y Interaction Are Modulated by Salicylic Acid

    PubMed Central

    Baebler, Špela; Stare, Katja; Kovač, Maja; Blejec, Andrej; Prezelj, Nina; Stare, Tjaša; Kogovšek, Polona; Pompe-Novak, Maruša; Rosahl, Sabine; Ravnikar, Maja; Gruden, Kristina

    2011-01-01

    To investigate the dynamics of the potato – Potato virus Y (PVY) compatible interaction in relation to salicylic acid - controlled pathways we performed experiments using non-transgenic potato cv. Désirée, transgenic NahG-Désirée, cv. Igor and PVYNTN, the most aggressive strain of PVY. The importance of salicylic acid in viral multiplication and symptom development was confirmed by pronounced symptom development in NahG-Désirée, depleted in salicylic acid, and reversion of the effect after spraying with 2,6-dichloroisonicotinic acid (a salicylic acid - analogue). We have employed quantitative PCR for monitoring virus multiplication, as well as plant responses through expression of selected marker genes of photosynthetic activity, carbohydrate metabolism and the defence response. Viral multiplication was the slowest in inoculated potato of cv. Désirée, the only asymptomatic genotype in the study. The intensity of defence-related gene expression was much stronger in both sensitive genotypes (NahG-Désirée and cv. Igor) at the site of inoculation than in asymptomatic plants (cv. Désirée). Photosynthesis and carbohydrate metabolism gene expression differed between the symptomatic and asymptomatic phenotypes. The differential gene expression pattern of the two sensitive genotypes indicates that the outcome of the interaction does not rely simply on one regulatory component, but similar phenotypical features can result from distinct responses at the molecular level. PMID:22194976

  14. Abscisic-acid-dependent basic leucine zipper (bZIP) transcription factors in plant abiotic stress.

    PubMed

    Banerjee, Aditya; Roychoudhury, Aryadeep

    2017-01-01

    One of the major causes of significant crop loss throughout the world is the myriad of environmental stresses including drought, salinity, cold, heavy metal toxicity, and ultraviolet-B (UV-B) rays. Plants as sessile organisms have evolved various effective mechanism which enable them to withstand this plethora of stresses. Most of such regulatory mechanisms usually follow the abscisic-acid (ABA)-dependent pathway. In this review, we have primarily focussed on the basic leucine zipper (bZIP) transcription factors (TFs) activated by the ABA-mediated signalosome. Upon perception of ABA by specialized receptors, the signal is transduced via various groups of Ser/Thr kinases, which phosphorylate the bZIP TFs. Following such post-translational modification of TFs, they are activated so that they bind to specific cis-acting sequences called abscisic-acid-responsive elements (ABREs) or GC-rich coupling elements (CE), thereby influencing the expression of their target downstream genes. Several in silico techniques have been adopted so far to predict the structural features, recognize the regulatory modification sites, undergo phylogenetic analyses, and facilitate genome-wide survey of TF under multiple stresses. Current investigations on the epigenetic regulation that controls greater accessibility of the inducible regions of DNA of the target gene to the bZIP TFs exclusively under stress situations, along with the evolved stress memory responses via genomic imprinting mechanism, have been highlighted. The potentiality of overexpression of bZIP TFs, either in a homologous or in a heterologous background, in generating transgenic plants tolerant to various abiotic stressors have also been addressed by various groups. The present review will provide a coherent documentation on the functional characterization and regulation of bZIP TFs under multiple environmental stresses, with the major goal of generating multiple-stress-tolerant plant cultivars in near future.

  15. Abscisic Acid Flux Alterations Result in Differential Abscisic Acid Signaling Responses and Impact Assimilation Efficiency in Barley under Terminal Drought Stress1[C][W][OPEN

    PubMed Central

    Seiler, Christiane; Harshavardhan, Vokkaliga T.; Reddy, Palakolanu S.; Hensel, Götz; Kumlehn, Jochen; Eschen-Lippold, Lennart; Rajesh, Kalladan; Korzun, Viktor; Wobus, Ulrich; Lee, Justin; Selvaraj, Gopalan; Sreenivasulu, Nese

    2014-01-01

    Abscisic acid (ABA) is a central player in plant responses to drought stress. How variable levels of ABA under short-term versus long-term drought stress impact assimilation and growth in crops is unclear. We addressed this through comparative analysis, using two elite breeding lines of barley (Hordeum vulgare) that show senescence or stay-green phenotype under terminal drought stress and by making use of transgenic barley lines that express Arabidopsis (Arabidopsis thaliana) 9-cis-epoxycarotenoid dioxygenase (AtNCED6) coding sequence or an RNA interference (RNAi) sequence of ABA 8′-hydroxylase under the control of a drought-inducible barley promoter. The high levels of ABA and its catabolites in the senescing breeding line under long-term stress were detrimental for assimilate productivity, whereas these levels were not perturbed in the stay-green type that performed better. In transgenic barley, drought-inducible AtNCED expression afforded temporal control in ABA levels such that the ABA levels rose sooner than in wild-type plants but also subsided, unlike as in the wild type , to near-basal levels upon prolonged stress treatment due to down-regulation of endogenous HvNCED genes. Suppressing of ABA catabolism with the RNA interference approach of ABA 8′-hydroxylase caused ABA flux during the entire period of stress. These transgenic plants performed better than the wild type under stress to maintain a favorable instantaneous water use efficiency and better assimilation. Gene expression analysis, protein structural modeling, and protein-protein interaction analyses of the members of the PYRABACTIN RESISTANCE1/PYRABACTIN RESISTANCE1-LIKE/REGULATORY COMPONENT OF ABA RECEPTORS, TYPE 2C PROTEIN PHOSPHATASE Sucrose non-fermenting1-related protein kinase2, and ABA-INSENSITIVE5/ABA-responsive element binding factor family identified specific members that could potentially impact ABA metabolism and stress adaptation in barley. PMID:24610749

  16. Abscisic acid-regulated responses of aba2-1 under osmotic stress: the abscisic acid-inducible antioxidant defence system and reactive oxygen species production.

    PubMed

    Ozfidan, C; Turkan, I; Sekmen, A H; Seckin, B

    2012-03-01

    We investigated the interaction among abscisic acid (ABA), reactive oxygen species (ROS) and antioxidant defence system in the transduction of osmotic stress signalling using Arabidopsis thaliana WT (Columbia ecotype, WT) and an ABA-deficient mutant (aba2-1). For this, 50 μm ABA and osmotic stress, induced with 40% (w/v) polyethylene glycol (PEG8000; -0.7 MPa), were applied to WT and aba2-1 for 6, 12 or 24 h. Time course analysis was undertaken for determination of total/isoenzyme activity of the antioxidant enzymes, superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APX; EC 1.11.1.11), NADPH oxidase (NOX; EC 1.6.3.1) activity; scavenging activity of the hydroxyl radical (OH˙), hydrogen peroxide (H(2) O(2) ); endogenous ABA and malondialdehyde (MDA). The highest H(2) O(2) and MDA content was found in PEG-treated groups of both genotypes, but with more in aba2-1. ABA treatment under stress reduced the accumulation of H(2) O(2) and MDA, while it promoted activity of SOD, CAT and APX. APX activity was higher than CAT activity in ABA-treated WT and aba2-1, indicating a protective role of APX rather than CAT during osmotic stress-induced oxidative damage. Treatment with ABA also significantly induced increased NOX activity. Oxidative damage was lower in ABA-treated seedlings of both genotypes, which was associated with greater activity of SOD (Mn-SOD1 and 2 and Fe-SOD isoenzymes), CAT and APX in these seedlings after 24 h of stress. These results suggest that osmotic stress effects were overcome by ABA treatment because of increased SOD, CAT, APX and NOX.

  17. [Effects of abscisic acid on chemical components content and color of Glycyrrhiza uralensis].

    PubMed

    Xiang, Yu; Liu, Chun-sheng; Liu, Yong; Song, Xiao-na; Gu, Xuan

    2015-05-01

    An experiment was conducted using cultivated Glycyrrhiza uralensis in age of one year to study the effects of abscisic acid (ABA) on chemical components content and color of G. uralensis. By using different concentrations of ABA spraying on leaves, the change of the chemical component content was analyzed within 45 d after ABA stimulation, and the effects on quality were studied combined with colorimetric analysis data. It turned out that in some sense the content of glycyrrhizic acid and liquiritin had increased within 45 d, especially for liquiritin. After high concentrations of ABA (3.96 mg · L(-1)) stimulating, the content of glycyrrhizic acid rose 52% while liquiritin up 392% within 30 d. Then they both showed a decline in the content of glycyrrhizic acid and liquiritin on 45 d. Color index values of a* and b* were all significantly higher than that of the control group within 45 d, which meant the color of powders turned toward red and yellow. The conclusion was that ABA (3.96 mg · L(-1)) stimulating could not only improve the quality in the traditional sense through the color of G. uralensis, but also in the modern sense by improving the content of glycyrrhizic acid and liquiritin.

  18. Pear 14-3-3a gene (Pp14-3-3a) is regulated during fruit ripening and senescense, and involved in response to salicylic acid and ethylene signalling.

    PubMed

    Shi, Haiyan; Zhang, Yuxing

    2014-12-01

    14-3-3 proteins play important roles in regulating plant development and phytohormone (abscisic acid, gibberellin and brassinosteroids) signalling. However, their regulation in fruit ripening and senescense, and response to salicylic acid and ethylene signalling are yet to be illustrated. One cDNA encoding putative 14-3-3 protein was isolated from pear (Pyrus pyrifolia) and designated Pp14-3-3a. Phylogenetic analysis clearly demonstrated that Pp14-3-3a belonged to ε-like group of 14-3-3 superfamilies. Real-time quantitative PCR analysis indicated that the expression of Pp14-3-3a gene was developmentally regulated in the fruit. Further study demonstrated that Pp14-3-3a expression was inhibited by salicylic acid and induced by ethylene precursor 1-aminocyclopropane-1-carboxylic acid in pear fruit. These data suggested that Pp14-3-3a might be involved in response to salicylic acid and ethylene signalling during fruit ripening and senescence of pear.

  19. Effect of methyl jasmonate, salicylic acid, Headline and Stadium on sucrose yield and storage properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl jasmonate (MeJA) and salicylic acid (SA) have been reported to enhance yield and protect crop plants and products against abiotic stresses and diseases. The effect of these compounds on sugarbeets, however, is unknown. Research was conducted in 2015 and 2016 to investigate the effects of an e...

  20. Salicylic Acid Improved In Viro Meristem Regeneration and Salt Tolerance in Two Hibiscus Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salicylic acid (SA) has been reported to induce abiotic stress, including salt tolerance in plants. The objective of this study was to determine whether application of various exogenous SA concentrations to in vitro grown meristem shoots could induce salt tolerance in two Hibiscus species. The effec...

  1. ENHANCED DISEASE SUSCEPTIBILITY 1 and SALICYLIC ACID act redundantly to regulate resistance gene-mediated signaling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance (R) protein–associated pathways are well known to participate in defense against a variety of microbial pathogens. Salicylic acid (SA) and its associated proteinaceous signaling components, including enhanced disease susceptibility 1 (EDS1), non–race-specific disease resistance 1 (NDR1), ...

  2. Effect of Salicylic Acid on Somatic Embryogenesis and Plant Regeneration in Hedychium bousigonianum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to induce somatic embryogenesis in Hedychium bousigonianum Pierre ex Gagnepain and assess the influence of salicylic acid (S) on somatic embryogenesis. Somatic embryos and subsequently regenerated plants were successfully obtained 30 days after transfer of embryogenic...

  3. Postharvest salicylic acid treatment reduces storage rots in water-stressed but no unstressed sugarbeet roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exogenous application of salicylic acid (SA) reduces storage rots in a number of postharvest crops. SA’s ability to protect sugarbeet (Beta vulgaris L.) taproots from common storage rot pathogens, however, is unknown. To determine the potential of SA to reduce storage losses caused by three common...

  4. Salicylic acid and heat acclimation pretreatment protects Laminaria japonica sporophyte (Phaeophyceae) from heat stress

    NASA Astrophysics Data System (ADS)

    Zhou, Bin; Tang, Xuexi; Wang, You

    2010-07-01

    Possible mediatory roles of heat acclimation and salicylic acid in protecting the sporophyte of marine macroalga Laminaria japonica (Phaeophyceae) from heat stress were studied. Heat stress resulted in oxidative injury in the kelp blades. Under heat stress significant accumulation of hydrogen peroxide (H2O2) and malonaldehyde (MDA), a membrane lipid peroxidation product, and a drastic decrease in chlorophyll a content were recorded. Activity of the enzymatic antioxidant system was drastically affected by heat stress. The activity of superoxide dismutase (SOD) was significantly increased while peroxidase (POD), catalase (CAT) and glutathione peroxidase (GPX) were greatly inhibited and, simultaneously, phenylalanine ammonia-lyase was activated while polyphenol oxidase (PPO) was inhibited. Both heat acclimation pretreatment and exogenous application of salicylic acid alleviated oxidative damage in kelp blades. Blades receiving heat acclimation pretreatment and exogenous salicylic acid prior to heat stress exhibited a reduced increase in H2O2 and MDA content, and a lower reduction in chlorophyll a content. Pretreatment with heat acclimation and salicylic acid elevated activities of SOD, POD, CAT, GPX and PPO. Considering these results collectively, we speculate that the inhibition of antioxidant enzymes is a possible cause of the heat-stress-induced oxidative stress in L. japonica, and enhanced thermotolerance may be associated, at least in part, with the elevated activity of the enzymatic antioxidant system.

  5. Low irradiances affect abscisic acid, indole-3-acidic acid, and cytokinin levels of wheat (Triticum aestivum L.) tissues

    NASA Technical Reports Server (NTRS)

    Nan, R.; Carman, J. G.; Salisbury, F. B.

    1999-01-01

    Wheat (Triticum aestivum L.) plants were grown under four irradiance levels: 1,400, 400, 200, and 100 micromol m-2 s-1. Leaves and roots were sampled before, during, and after the boot stage, and levels of abscisic acid (ABA), indole-3-acetic acid (IAA), zeatin, zeatin riboside, dihydrozeatin, dihydrozeatin riboside, isopentenyl adenine, and isopentenyl adenosine were quantified using noncompetitive indirect ELISA systems. Levels of IAA in leaves and roots of plants exposed to 100 micromol m-2 s-1 of irradiance were 0.7 and 2.9 micromol kg-1 dry mass (DM), respectively. These levels were 0.2 and 1.0 micromol kg-1 DM, respectively, when plants were exposed to 1,400 micromol m-2 s-1. Levels of ABA in leaves and roots of plants exposed to 100 micromol m-2 s-1 were 0.65 and 0.55 micromol kg-1 DM, respectively. They were 0.24 micromol kg-1 DM (both leaves and roots) when plants were exposed to 1,400 micromol m-2 s-1. Levels of isopentenyl adenosine in leaves (24.3 nmol kg-1 DM) and roots (29.9 nmol kg-1 DM) were not affected by differences in the irradiance regime. Similar values were obtained in a second experiment. Other cytokinins could not be detected (<10 nmol kg 1 DM) in either experiment with the sample sizes used (150-600 mg DM for roots and shoots, respectively).

  6. Involvement of a lipoxygenase-like enzyme in abscisic Acid biosynthesis.

    PubMed

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

    1992-07-01

    Several lines of evidence indicate that abscisic acid (ABA) is derived from 9'-cis-neoxanthin or 9'-cis-violaxanthin with xanthoxin as an intermediate. (18)O-labeling experiments show incorporation primarily into the side chain carboxyl group of ABA, suggesting that oxidative cleavage occurs at the 11, 12 (11', 12') double bond of xanthophylls. Carbon monoxide, a strong inhibitor of heme-containing P-450 monooxygenases, did not inhibit ABA accumulation, suggesting that the oxygenase catalyzing the carotenoid cleavage step did not contain heme. This observation, plus the ability of lipoxygenase to make xanthoxin from violaxanthin, suggested that a lipoxygenase-like enzyme is involved in ABA biosynthesis. To test this idea, the ability of several soybean (Glycine max L.) lipoxygenase inhibitors (5,8,11-eicosatriynoic acid, 5,8,11,14-eicosatetraynoic acid, nordihydroguaiaretic acid, and naproxen) to inhibit stress-induced ABA accumulation in soybean cell culture and soybean seedlings was determined. All lipoxygenase inhibitors significantly inhibited ABA accumulation in response to stress. These results suggest that the in vivo oxidative cleavage reaction involved in ABA biosynthesis requires activity of a nonheme oxygenase having lipoxygenase-like properties.

  7. Chlorogenic Acids Biosynthesis in Centella asiatica Cells Is not Stimulated by Salicylic Acid Manipulation.

    PubMed

    Ncube, E N; Steenkamp, P A; Madala, N E; Dubery, I A

    2016-07-01

    Exogenous application of synthetic and natural elicitors of plant defence has been shown to result in mass production of secondary metabolites with nutraceuticals properties in cultured cells. In particular, salicylic acid (SA) treatment has been reported to induce the production of phenylpropanoids, including cinnamic acid derivatives bound to quinic acid (chlorogenic acids). Centella asiatica is an important medicinal plant with several therapeutic properties owing to its wide spectrum of secondary metabolites. We investigated the effect of SA on C. asiatica cells by monitoring perturbation of chlorogenic acids in particular. Different concentrations of SA were used to treat C. asiatica cells, and extracts from both treated and untreated cells were analysed using an optimised UHPLC-QTOF-MS/MS method. Semi-targeted multivariate data analyses with the aid of principal component analysis (PCA) and orthogonal projection to latent structures-discriminant analysis (OPLS-DA) revealed a concentration-dependent metabolic response. Surprisingly, a range of chlorogenic acid derivatives were found to be downregulated as a consequence of SA treatment. Moreover, irbic acid (3,5-O-dicaffeoyl-4-O-malonilquinic acid) was found to be a dominant CGA in C. asiatica cells, although the SA treatment also had a negative effect on its concentration. Overall SA treatment was found to be an ineffective elicitor of CGA production in cultured C. asiatica cells.

  8. Abscisic acid related compounds and lignans in prunes (Prunus domestica L.) and their oxygen radical absorbance capacity (ORAC).

    PubMed

    Kikuzaki, Hiroe; Kayano, Shin-ichi; Fukutsuka, Naoko; Aoki, Asuka; Kasamatsu, Kumi; Yamasaki, Yuka; Mitani, Takahiko; Nakatani, Nobuji

    2004-01-28

    Four new abscisic acid related compounds (1-4), together with (+)-abscisic acid (5), (+)-beta-D-glucopyranosyl abscisate (6), (6S,9R)-roseoside (7), and two lignan glucosides ((+)-pinoresinol mono-beta-D-glucopyranoside (8) and 3-(beta-D-glucopyranosyloxymethyl)-2- (4-hydroxy-3-methoxyphenyl)-5-(3-hydroxypropyl)-7-methoxy-(2R,3S)-dihydrobenzofuran (9)) were isolated from the antioxidative ethanol extract of prunes (Prunus domestica L.). The structures of 1-4 were elucidated on the basis of NMR and MS spectrometric data to be rel-5-(3S,8S-dihydroxy-1R,5S-dimethyl-7-oxa-6-oxobicyclo[3,2,1]oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid (1), rel-5-(3S,8S-dihydroxy-1R,5S-dimethyl-7-oxa-6-oxobicyclo[3,2,1]oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid 3'-O-beta-d-glucopyranoside (2), rel-5-(1R,5S-dimethyl-3R,4R,8S-trihydroxy-7-oxa-6-oxobicyclo[3,2,1]oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid (3), and rel-5-(1R,5S-dimethyl-3R,4R,8S-trihydroxy-7-oxabicyclo[3,2,1]- oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid (4). The antioxidant activities of these isolated compounds were evaluated on the basis of oxygen radical absorbance capacity (ORAC). The ORAC values of abscisic acid related compounds (1-7) were very low. Two lignans (8 and 9) were more effective antioxidants whose ORAC values were 1.09 and 2.33 micromol of Trolox equiv/micromol, respectively.

  9. 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

  10. Nitric oxide production occurs after cytosolic alkalinization during stomatal closure induced by abscisic acid.

    PubMed

    Gonugunta, Vijay K; Srivastava, Nupur; Puli, Mallikarjuna R; Raghavendra, Agepati S

    2008-11-01

    Abscisic acid (ABA) raised the cytosolic pH and nitric oxide (NO) levels in guard cells while inducing stomatal closure in epidermis of Pisum sativum. Butyrate (a weak acid) reduced the cytosolic pH/NO production and prevented stomatal closure by ABA. Methylamine (a weak base) enhanced the cytosolic alkalinization and aggravated stomatal closure by ABA. The rise in guard cell pH because of ABA became noticeable after 6 min and peaked at 12 min, while NO production started at 9 min and peaked at 18 min. These results suggested that NO production was downstream of the rise in cytosolic pH. The ABA-induced increase in NO of guard cells and stomatal closure was prevented by 2-phenyl-4,4,5,5-tetramethyl imidazoline-1-oxyl 3-oxide (cPTIO, a NO scavenger) and partially by N-nitro-L-Arg-methyl ester (L-NAME, an inhibitor of NO synthase). In contrast, cPTIO or L-NAME had only a marginal effect on the pH rise induced by ABA. Ethylene glycol tetraacetic acid (EGTA, a calcium chelator) prevented ABA-induced stomatal closure while restricting cytosolic pH rise and NO production. We suggest that during ABA-induced stomatal closure, a rise in cytosolic pH is necessary for NO production. Calcium may act upstream of cytosolic alkalinization and NO production, besides its known function as a downstream component.

  11. Involvement of Abscisic Acid in Ethylene-Induced Cotyledon Abscission in Cotton Seedlings.

    PubMed Central

    Suttle, J. C.; Hultstrand, J. F.

    1993-01-01

    Cotton (Gossypium hirsutum L. cv LG102) seedlings raised from seeds exposed to 100 [mu]M norflurazon (NFZ) during imbibition contained reduced levels of free abscisic acid (ABA) and were visibly achlorophyllous. Exposure of untreated cotton seedlings to ethylene concentrations >1 [mu]L/L for 24 h resulted in cotyledon abscission. In contrast, exposure of NFZ-treated seedlings to concentrations of ethylene [less than or equal to]50 [mu]L/L elicited no cotyledon abscission. Application of ABA, an ABA analog, or jasmonic acid to NFZ-treated seedlings restored ethylene-induced abscission. Isolated cotyledonary node explants prepared from NFZ-treated seedlings exhibited an altered dose-response pattern of ethylene-induced petiole abscission. Endogenous levels of free IAA were unaltered in NFZ-treated seedlings. Ethylene treatment (50 [mu]L/L, 24 h) had no effect on free indoleacetic acid (IAA) levels in either control or NFZ-treated seedlings. Levels of conjugated (ester plus amide) IAA were substantially increased in NFZ-treated seedlings regardless of ethylene treatment. These results indicate that endogenous ABA plays an essential, but physiologically undefined, role in ethylene-induced cotyledon abscission in cotton. PMID:12231720

  12. Violaxanthin is an abscisic acid precursor in water-stressed dark-grown bean leaves

    SciTech Connect

    Li, Yi; Walton, D.C. )

    1990-03-01

    The leaves a dark-grown bean (Phaseolus vulgaris L.) seedlings accumulate considerably lower quantities of xanthophylls and carotenes than do leaves of light-grown seedlings, but they synthesize at least comparable amounts of abscisic acid (ABA) and its metabolites when water stressed. We observed a 1:1 relationship on a molar basis between the reduction in levels of ciolaxanthin, 9{prime}-cis-neoxanthin, and 9-cis-violaxanthin and the accumulation of ABA, phaseic acid, and dihydrophaseic acid, when leaves from dark-grown plants were stressed for 7 hours. Early in the stress period, reductions in xanthophylls were greater than the accumulation of ABA and its metabolites, suggesting the accumulation of an intermediate which was subsequently converted to ABA. Leaves which were detached, but no stressed, did not accumulate ABA nor were their xanthophyll levels reduced. Leaves from plants that had been sprayed with cycloheximido did not accumulate ABA when stressed, nor were their xanthophyll levels reduced significantly. Incubation of dark-grown stressed leaves in an {sup 18}O{sub 2}-containing atmosphere resulted in the synthesis of ABA with levels of {sup 18}O in the carboxyl group that were virtually identical to those observed in light-grown leaves. The results of these experiments indicate that violaxanthin is an ABA precursor in stressed dark-grown leaves, and they are used to suggest several possible pathways from violaxanthin to ABA.

  13. Control of macaw palm seed germination by the gibberellin/abscisic acid balance.

    PubMed

    Bicalho, E M; Pintó-Marijuan, M; Morales, M; Müller, M; Munné-Bosch, S; Garcia, Q S

    2015-09-01

    The hormonal mechanisms involved in palm seed germination are not fully understood. To better understand how germination is regulated in Arecaceae, we used macaw palm (Acrocomia aculeata (Jacq.) Lodd. Ex Mart.) seed as a model. Endogenous hormone concentrations, tocopherol and tocotrienol and lipid peroxidation during germination were studied separately in the embryo and endosperm. Evaluations were performed in dry (D), imbibed (I), germinated (G) and non-germinated (NG) seeds treated (+GA3 ) or not treated (control) with gibberellins (GA). With GA3 treatment, seeds germinated faster and to a higher percentage than control seeds. The +GA3 treatment increased total bioactive GA in the embryo during germination relative to the control. Abscisic acid (ABA) concentrations decreased gradually from D to G in both tissues. Embryos of G seeds had a lower ABA content than NG seeds in both treatments. The GA/ABA ratio in the embryo was significantly higher in G than NG seeds. The +GA3 treatment did not significantly affect the GA/ABA ratio in either treatment. Cytokinin content increased from dry to germinated seeds. Jasmonic acid (JA) increased and 1-aminocyclopropane-1-carboylic acid (ACC) decreased after imbibition. In addition, α-tocopherol and α-tocotrienol decreased, while lipid peroxidation increased in the embryo during germination. We conclude that germination in macaw palm seed involves reductions in ABA content and, consequently, increased GA/ABA in the embryo. Furthermore, the imbibition process generates oxidative stress (as observed by changes in vitamin E and MDA).

  14. Biodegradation of phenol, salicylic acid, benzenesulfonic acid, and iomeprol by Pseudomonas fluorescens in the capillary fringe

    NASA Astrophysics Data System (ADS)

    Hack, Norman; Reinwand, Christian; Abbt-Braun, Gudrun; Horn, Harald; Frimmel, Fritz H.

    2015-12-01

    Mass transfer and biological transformation phenomena in the capillary fringe were studied using phenol, salicylic acid, benzenesulfonic acid, and the iodinated X-ray contrast agent iomeprol as model organic compounds and the microorganism strain Pseudomonas fluorescens. Three experimental approaches were used: Batch experiments (uniform water saturation and transport by diffusion), in static columns (with a gradient of water saturation and advective transport in the capillaries) and in a flow-through cell (with a gradient of water saturation and transport by horizontal and vertical flow: 2-dimension flow-through microcosm). The reactors employed for the experiments were filled with quartz sand of defined particle size distribution (dp = 200…600 μm, porosity ε = 0.42). Batch experiments showed that phenol and salicylic acid have a high, whereas benzenesulfonic acid and iomeprol have a quite low potential for biodegradation under aerobic conditions and in a matrix nearly close to water saturation. Batch experiments under anoxic conditions with nitrate as electron acceptor revealed that the biodegradation of the model compounds was lower than under aerobic conditions. Nevertheless, the experiments showed that the moisture content was also responsible for an optimized transport in the liquid phase of a porous medium. Biodegradation in the capillary fringe was found to be influenced by both the moisture content and availability of the dissolved substrate, as seen in static column experiments. The gas-liquid mass transfer of oxygen also played an important role for the biological activity. In static column experiments under aerobic conditions, the highest biodegradation was found in the capillary fringe (e.g. βt/β0 (phenol) = 0 after t = 6 d) relative to the zone below the water table and unsaturated zone. The highest biodegradation occurred in the flow-through cell experiment where the height of the capillary fringe was largest.

  15. Biodegradation of phenol, salicylic acid, benzenesulfonic acid, and iomeprol by Pseudomonas fluorescens in the capillary fringe.

    PubMed

    Hack, Norman; Reinwand, Christian; Abbt-Braun, Gudrun; Horn, Harald; Frimmel, Fritz H

    2015-12-01

    Mass transfer and biological transformation phenomena in the capillary fringe were studied using phenol, salicylic acid, benzenesulfonic acid, and the iodinated X-ray contrast agent iomeprol as model organic compounds and the microorganism strain Pseudomonas fluorescens. Three experimental approaches were used: Batch experiments (uniform water saturation and transport by diffusion), in static columns (with a gradient of water saturation and advective transport in the capillaries) and in a flow-through cell (with a gradient of water saturation and transport by horizontal and vertical flow: 2-dimension flow-through microcosm). The reactors employed for the experiments were filled with quartz sand of defined particle size distribution (dp=200...600 μm, porosity ε=0.42). Batch experiments showed that phenol and salicylic acid have a high, whereas benzenesulfonic acid and iomeprol have a quite low potential for biodegradation under aerobic conditions and in a matrix nearly close to water saturation. Batch experiments under anoxic conditions with nitrate as electron acceptor revealed that the biodegradation of the model compounds was lower than under aerobic conditions. Nevertheless, the experiments showed that the moisture content was also responsible for an optimized transport in the liquid phase of a porous medium. Biodegradation in the capillary fringe was found to be influenced by both the moisture content and availability of the dissolved substrate, as seen in static column experiments. The gas-liquid mass transfer of oxygen also played an important role for the biological activity. In static column experiments under aerobic conditions, the highest biodegradation was found in the capillary fringe (e.g. βt/β0 (phenol)=0 after t=6 d) relative to the zone below the water table and unsaturated zone. The highest biodegradation occurred in the flow-through cell experiment where the height of the capillary fringe was largest.

  16. 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.

  17. Effects of exogenous abscisic acid on yield, antioxidant capacities, and phytochemical contents of greenhouse grown lettuces.

    PubMed

    Li, Zheng; Zhao, Xin; Sandhu, Amandeep K; Gu, Liwei

    2010-05-26

    Antioxidants and phytochemicals in vegetables are known to provide health benefits. Strategies that enhance these properties are expected to increase the nutritional values of vegetables. The objective of this research is to assess the effects of exogenous abscisic acid (ABA) on yield, antioxidant capacities, and phytochemical content of lettuces grown in a greenhouse. Red loose leaf lettuce (cv. Galactic) and green loose leaf lettuce (cv. Simpson Elite) were cultivated using a randomized complete block design. Three concentrations of ABA in water [0 (control), 150, 300 ppm] were sprayed on the 30th and 39th days after sowing, and lettuces were harvested on the 46th day. Exogenous ABA significantly decreased yield of green and red lettuces. Total phenolic and total anthocyanin contents in red lettuce treated with ABA were significantly higher than in controls, whereas no significant differences were observed in green lettuce. ABA significantly induced the accumulation of chlorophyll b and total carotenoids in lettuces. The phenolic compounds identified and quantified in red and green lettuces included caffeoyltartaric acid, 5-O-caffeoylquinic acid, dicaffeoyltartaric acid, 3,5-dicaffeoylquinic acid, and quercetin 3-(6''-malonyl)-glucoside. Additionally, cyanidin 3-glucoside, cyanidin 3-(3''-malonoyl)-glucoside, and cyanidin 3-(6''-malonoyl)-glucoside in red lettuces were quantified. No significant effects of ABA on these individual phytochemicals were observed in green lettuces, whereas ABA significantly elevated the content of individual phytochemicals in red lettuces except for 5-O-caffeoylquinic acid. Differences among red lettuces with or without exogenous ABA were visualized on the score plots of principal component analyses. Loading plot indicated that multiple phenolic compounds contributed to the observed differences in red lettuces.

  18. Benzoic acid 2-hydroxylase, a soluble oxygenase from tobacco, catalyzes salicylic acid biosynthesis

    SciTech Connect

    Leon, J.; Shulaev, V.; Yalpani, N.

    1995-10-24

    Benzoic acid 2-hydroxylase (BA2H) catalyzes the biosynthesis of salicylic acid from benzoic acid. The enzyme has been partially purified and characterized as a soluble protein of 160 kDa. High-efficiency in vivo labeling of salicyclic acid with {sup 18}O{sub 2} suggested that BA2H is an oxygenase that specifically hydroxylates the ortho position of benzoic acid. The enzyme was strongly induced by either tobacco mosaic virus inoculation of benzoic acid infiltration of tobacco leaves and it was inhibited by CO and other inhibitors of cytochrome P450 hydroxylases. The BA2H activity was immunodepleted by antibodies raised against SU2, a soluble cytochrome P450 from Streptomyces griseolus. The anti-SU2 antibodies immunoprecipitated a radiolabeled polypeptide of around 160 kDa from the soluble protein extracts of L-[{sup 35}S]-methionine-fed tobacco leaves. Purified BA2H showed CO-difference spectra with a maximum at 457 nm. These data suggest that BA2H belongs to a novel class of soluble, high molecular weight cytochrome P450 enzymes. 21 refs., 6 figs., 1 tab.

  19. Relative quantification of phosphoproteomic changes in grapevine (Vitis vinifera L.) leaves in response to abscisic acid

    PubMed Central

    Rattanakan, Supakan; George, Iniga; Haynes, Paul A; Cramer, Grant R

    2016-01-01

    In a previous transcriptomic analysis, abscisic acid (ABA) was found to affect the abundance of a number of transcripts in leaves of Cabernet Sauvignon grapevines with roots that had been exposed to 10 μm ABA for 2 h. Other work has indicated that ABA affects protein abundance and protein phosphorylation as well. In this study we investigated changes in protein abundance and phosphorylation of Cabernet Sauvignon grapevine leaves. Protein abundance was assessed by both label-free and isobaric-label quantitive proteomic methods. Each identified common proteins, but also additional proteins not found with the other method. Overall, several thousand proteins were identified and several hundred were quantified. In addition, hundreds of phosphoproteins were identified. Tens of proteins were found to be affected in the leaf after the roots had been exposed to ABA for 2 h, more than half of them were phosphorylated proteins. Many phosphosites were confirmed and several new ones were identified. ABA increased the abundance of some proteins, but the majority of the proteins had their protein abundance decreased. Many of these proteins were involved in growth and plant organ development, including proteins involved in protein synthesis, photosynthesis, sugar and amino-acid metabolism. This study provides new insights into how ABA regulates plant responses and acclimation to water deficits. PMID:27366326

  20. Ethylene limits abscisic acid- or soil drying-induced stomatal closure in aged wheat leaves.

    PubMed

    Chen, Lin; Dodd, Ian C; Davies, William J; Wilkinson, Sally

    2013-10-01

    The mechanism of age-induced decreased stomatal sensitivity to abscisic acid (ABA) and soil drying has been explored here. Older, fully expanded leaves partly lost their ability to close stomata in response to foliar ABA sprays, and soil drying which stimulated endogenous ABA production, while young fully expanded leaves closed their stomata more fully. However, ABA- or soil drying-induced stomatal closure of older leaves was partly restored by pretreating plants with 1-methylcyclopropene (1-MCP), which can antagonize ethylene receptors, or by inoculating soil around the roots with the rhizobacterium Variovorax paradoxus 5C-2, which contains 1-aminocyclopropane-1-carboxylic acid (ACC)-deaminase. ACC (the immediate biosynthetic precursor of ethylene) sprays revealed higher sensitivity of stomata to ethylene in older leaves than younger leaves, despite no differences in endogenous ACC concentrations or ethylene emission. Taken together, these results indicate that the relative insensitivity of stomatal closure to ABA and soil drying in older leaves is likely due to altered stomatal sensitivity to ethylene, rather than ethylene production. To our knowledge, this is the first study to mechanistically explain diminished stomatal responses to soil moisture deficit in older leaves, and the associated reduction in leaf water-use efficiency.

  1. Functional convergence of oxylipin and abscisic acid pathways controls stomatal closure in response to drought.

    PubMed

    Savchenko, Tatyana; Kolla, Venkat A; Wang, Chang-Quan; Nasafi, Zainab; Hicks, Derrick R; Phadungchob, Bpantamars; Chehab, Wassim E; Brandizzi, Federica; Froehlich, John; Dehesh, Katayoon

    2014-03-01

    Membranes are primary sites of perception of environmental stimuli. Polyunsaturated fatty acids are major structural constituents of membranes that also function as modulators of a multitude of signal transduction pathways evoked by environmental stimuli. Different stresses induce production of a distinct blend of oxygenated polyunsaturated fatty acids, "oxylipins." We employed three Arabidopsis (Arabidopsis thaliana) ecotypes to examine the oxylipin signature in response to specific stresses and determined that wounding and drought differentially alter oxylipin profiles, particularly the allene oxide synthase branch of the oxylipin pathway, responsible for production of jasmonic acid (JA) and its precursor 12-oxo-phytodienoic acid (12-OPDA). Specifically, wounding induced both 12-OPDA and JA levels, whereas drought induced only the precursor 12-OPDA. Levels of the classical stress phytohormone abscisic acid (ABA) were also mainly enhanced by drought and little by wounding. To explore the role of 12-OPDA in plant drought responses, we generated a range of transgenic lines and exploited the existing mutant plants that differ in their levels of stress-inducible 12-OPDA but display similar ABA levels. The plants producing higher 12-OPDA levels exhibited enhanced drought tolerance and reduced stomatal aperture. Furthermore, exogenously applied ABA and 12-OPDA, individually or combined, promote stomatal closure of ABA and allene oxide synthase biosynthetic mutants, albeit most effectively when combined. Using tomato (Solanum lycopersicum) and Brassica napus verified the potency of this combination in inducing stomatal closure in plants other than Arabidopsis. These data have identified drought as a stress signal that uncouples the conversion of 12-OPDA to JA and have revealed 12-OPDA as a drought-responsive regulator of stomatal closure functioning most effectively together with ABA.

  2. Development of a Controlled Release of Salicylic Acid Loaded Stearic Acid-Oleic Acid Nanoparticles in Cream for Topical Delivery

    PubMed Central

    Woo, J. O.; Misran, M.; Lee, P. F.; Tan, L. P.

    2014-01-01

    Lipid nanoparticles are colloidal carrier systems that have extensively been investigated for controlled drug delivery, cosmetic and pharmaceutical applications. In this work, a cost effective stearic acid-oleic acid nanoparticles (SONs) with high loading of salicylic acid, was prepared by melt emulsification method combined with ultrasonication technique. The physicochemical properties, thermal analysis and encapsulation efficiency of SONs were studied. TEM micrographs revealed that incorporation of oleic acid induces the formation of elongated spherical particles. This observation is in agreement with particle size analysis which also showed that the mean particle size of SONs varied with the amount of OA in the mixture but with no effect on their zeta potential values. Differential scanning calorimetry analysis showed that the SONs prepared in this method have lower crystallinity as compared to pure stearic acid. Different amount of oleic acid incorporated gave different degree of perturbation to the crystalline matrix of SONs and hence resulted in lower degrees of crystallinity, thereby improving their encapsulation efficiencies. The optimized SON was further incorporated in cream and its in vitro release study showed a gradual release for 24 hours, denoting the incorporation of salicylic acid in solid matrix of SON and prolonging the in vitro release. PMID:24578624

  3. Detection of phytohormones in temperate forest fungi predicts consistent abscisic acid production and a common pathway for cytokinin biosynthesis.

    PubMed

    Morrison, Erin N; Knowles, Sarah; Hayward, Allison; Thorn, R Greg; Saville, Barry J; Emery, R J N

    2015-01-01

    The phytohormones, abscisic acid and cytokinin, once were thought to be present uniquely in plants, but increasing evidence suggests that these hormones are present in a wide variety of organisms. Few studies have examined fungi for the presence of these "plant" hormones or addressed whether their levels differ based on the nutrition mode of the fungus. This study examined 20 temperate forest fungi of differing nutritional modes (ectomycorrhizal, wood-rotting, saprotrophic). Abscisic acid and cytokinin were present in all fungi sampled; this indicated that the sampled fungi have the capacity to synthesize these two classes of phytohormones. Of the 27 cytokinins analyzed by HPLC-ESI MS/MS, seven were present in all fungi sampled. This suggested the existence of a common cytokinin metabolic pathway in fungi that does not vary among different nutritional modes. Predictions regarding the source of isopentenyl, cis-zeatin and methylthiol CK production stemming from the tRNA degradation pathway among fungi are discussed.

  4. Changes in actin dynamics are involved in salicylic acid signaling pathway.

    PubMed

    Matoušková, Jindřiška; Janda, Martin; Fišer, Radovan; Sašek, Vladimír; Kocourková, Daniela; Burketová, Lenka; Dušková, Jiřina; Martinec, Jan; Valentová, Olga

    2014-06-01

    Changes in actin cytoskeleton dynamics are one of the crucial players in many physiological as well as non-physiological processes in plant cells. Positioning of actin filament arrays is necessary for successful establishment of primary lines of defense toward pathogen attack, depolymerization leads very often to the enhanced susceptibility to the invading pathogen. On the other hand it was also shown that the disruption of actin cytoskeleton leads to the induction of defense response leading to the expression of PATHOGENESIS RELATED proteins (PR). In this study we show that pharmacological actin depolymerization leads to the specific induction of genes in salicylic acid pathway but not that involved in jasmonic acid signaling. Life imaging of leafs of Arabidopsis thaliana with GFP-tagged fimbrin (GFP-fABD2) treated with 1 mM salicylic acid revealed rapid disruption of actin filaments resembling the pattern viewed after treatment with 200 nM latrunculin B. The effect of salicylic acid on actin filament fragmentation was prevented by exogenous addition of phosphatidic acid, which binds to the capping protein and thus promotes actin polymerization. The quantitative evaluation of actin filament dynamics is also presented.

  5. Folic acid induces salicylic acid-dependent immunity in Arabidopsis and enhances susceptibility to Alternaria brassicicola.

    PubMed

    Wittek, Finni; Kanawati, Basem; Wenig, Marion; Hoffmann, Thomas; Franz-Oberdorf, Katrin; Schwab, Wilfried; Schmitt-Kopplin, Philippe; Vlot, A Corina

    2015-08-01

    Folates are essential for one-carbon transfer reactions in all organisms and contribute, for example, to de novo DNA synthesis. Here, we detected the folate precursors 7,8-dihydropteroate (DHP) and 4-amino-4-deoxychorismate (ADC) in extracts from Arabidopsis thaliana plants by Fourier transform ion cyclotron resonance-mass spectrometry. The accumulation of DHP, but not ADC, was induced after infection of plants with Pseudomonas syringae delivering the effector protein AvrRpm1. Application of folic acid or the DHP precursor 7,8-dihydroneopterin (DHN) enhanced resistance in Arabidopsis to P. syringae and elevated the transcript accumulation of the salicylic acid (SA) marker gene pathogenesis-related1 in both the treated and systemic untreated leaves. DHN- and folic acid-induced systemic resistance was dependent on SA biosynthesis and signalling. Similar to SA, folic acid application locally enhanced Arabidopsis susceptibility to the necrotrophic fungus Alternaria brassicicola. Together, the data associate the folic acid pathway with innate immunity in Arabidopsis, simultaneously activating local and systemic SA-dependent resistance to P. syringae and suppressing local resistance to A. brassicicola.

  6. Nucleotide sequence and spatial expression pattern of a drought- and abscisic Acid-induced gene of tomato.

    PubMed

    Plant, A L; Cohen, A; Moses, M S; Bray, E A

    1991-11-01

    The nucleotide sequence of le16, a tomato (Lycopersicon esculentum Mill.) gene induced by drought stress and regulated by abscisic acid specifically in aerial vegetative tissue, is presented. The single open reading frame contained within the gene has the capacity to encode a polypeptide of 12.7 kilodaltons and is interrupted by a small intron. The predicted polypeptide is rich in leucine, glycine, and alanine and has an isoelectric point of 8.7. The amino terminus is hydrophobic and characteristic of signal sequences that target polypeptides for export from the cytoplasm. There is homology (47.2% identity) between the amino terminus of the LE 16 polypeptide and the corresponding amino terminal domain of the maize phospholipid transfer protein. le16 was expressed in drought-stressed leaf, petiole, and stem tissue and to a much lower extent in the pericarp of mature green tomato fruit and developing seeds. No expression was detected in the pericarp of red fruit or in drought-stressed roots. Expression of le16 was also induced in leaf tissue by a variety of other abiotic stresses including polyethylene glycol-mediated water deficit, salinity, cold stress, and heat stress. None of these stresses or direct applications of abscisic acid induced the expression of le16 in the roots of the same plants. The unique expression characteristics of this gene indicates that novel regulatory mechanisms, in addition to endogenous abscisic acid, are involved in controlling gene expression.

  7. Stimulation of the Salicylic Acid Pathway Aboveground Recruits Entomopathogenic Nematodes Belowground

    PubMed Central

    Filgueiras, Camila Cramer; Willett, Denis S.; Junior, Alcides Moino; Pareja, Martin; Borai, Fahiem El; Dickson, Donald W.; Stelinski, Lukasz L.; Duncan, Larry W.

    2016-01-01

    Plant defense pathways play a critical role in mediating tritrophic interactions between plants, herbivores, and natural enemies. While the impact of plant defense pathway stimulation on natural enemies has been extensively explored aboveground, belowground ramifications of plant defense pathway stimulation are equally important in regulating subterranean pests and still require more attention. Here we investigate the effect of aboveground stimulation of the salicylic acid pathway through foliar application of the elicitor methyl salicylate on belowground recruitment of the entomopathogenic nematode, Steinernema diaprepesi. Also, we implicate a specific root-derived volatile that attracts S. diaprepesi belowground following aboveground plant stimulation by an elicitor. In four-choice olfactometer assays, citrus plants treated with foliar applications of methyl salicylate recruited S. diaprepesi in the absence of weevil feeding as compared with negative controls. Additionally, analysis of root volatile profiles of citrus plants receiving foliar application of methyl salicylate revealed production of d-limonene, which was absent in negative controls. The entomopathogenic nematode S. diaprepesi was recruited to d-limonene in two-choice olfactometer trials. These results reinforce the critical role of plant defense pathways in mediating tritrophic interactions, suggest a broad role for plant defense pathway signaling belowground, and hint at sophisticated plant responses to pest complexes. PMID:27136916

  8. Abscisic Acid-Induced Resistance against the Brown Spot Pathogen Cochliobolus miyabeanus in Rice Involves MAP Kinase-Mediated Repression of Ethylene Signaling1[C][W][OA

    PubMed Central

    De Vleesschauwer, David; Yang, Yinong; Vera Cruz, Casiana; Höfte, Monica

    2010-01-01

    The plant hormone abscisic acid (ABA) is involved in an array of plant processes, including the regulation of gene expression during adaptive responses to various environmental cues. Apart from its well-established role in abiotic stress adaptation, emerging evidence indicates that ABA is also prominently involved in the regulation and integration of pathogen defense responses. Here, we demonstrate that exogenously administered ABA enhances basal resistance of rice (Oryza sativa) against the brown spot-causing ascomycete Cochliobolus miyabeanus. Microscopic analysis of early infection events in control and ABA-treated plants revealed that this ABA-inducible resistance (ABA-IR) is based on restriction of fungal progression in the mesophyll. We also show that ABA-IR does not rely on boosted expression of salicylic acid-, jasmonic acid -, or callose-dependent resistance mechanisms but, instead, requires a functional Gα-protein. In addition, several lines of evidence are presented suggesting that ABA steers its positive effect on brown spot resistance through antagonistic cross talk with the ethylene (ET) response pathway. Exogenous ethephon application enhances susceptibility, whereas genetic disruption of ET signaling renders plants less vulnerable to C. miyabeanus attack, thereby inducing a level of resistance similar to that observed on ABA-treated wild-type plants. Moreover, ABA treatment alleviates C. miyabeanus-induced activation of the ET reporter gene EBP89, while derepression of pathogen-triggered EBP89 transcription via RNA interference-mediated knockdown of OsMPK5, an ABA-primed mitogen-activated protein kinase gene, compromises ABA-IR. Collectively, these data favor a model whereby exogenous ABA enhances resistance against C. miyabeanus at least in part by suppressing pathogen-induced ET action in an OsMPK5-dependent manner. PMID:20130100

  9. The Effects of Salicylic Acid on Juvenile Zebrafish Danio rerio Under Flow-Through Conditions.

    PubMed

    Zivna, Dana; Blahova, Jana; Siroka, Zuzana; Plhalova, Lucie; Marsalek, Petr; Doubkova, Veronika; Zelinska, Gabriela; Vecerek, Vladimir; Tichy, Frantisek; Sehonova, Pavla; Svobodova, Zdenka

    2016-09-01

    The aquatic environment is becoming increasingly contaminated with pharmaceuticals. Salicylic acid (SA), which can be used individually or appear as a degradation product of the widely used acetylsalicylic acid was chosen for testing. Juvenile zebrafish Danio rerio were subjected to OECD test No. 215 (fish, juvenile growth test) with salicylic acid concentrations of 0.004; 0.04; 0.4; 4 and 40 mg/L. Specific growth rate (SGR), histological changes, and parameters of oxidative stress were evaluated. SA had no effects on histological changes, SGR, glutathione reductase, and lipid peroxidation. Increased catalytic activity of GPx was found at 0.04 mg/L compared to control, increased catalytic activity of catalase was found at 0.04 and 4 mg/L compared to control, and increased catalytic activity of glutathione-S-transferase was found at 0.004 and 0.04 mg/L compared to control (P < 0.05). Juvenile zebrafish turned out to be relatively insensitive to both environmentally relevant (0.004 mg/L) and higher concentrations of salicylic acid.

  10. Osmotic stress, endogenous abscisic acid and the control of leaf morphology in Hippuris vulgaris L

    NASA Technical Reports Server (NTRS)

    Goliber, T. E.; Feldman, L. J.

    1989-01-01

    Previous reports indicate that heterophyllous aquatic plants can be induced to form aerial-type leaves on submerged shoots when they are grown in exogenous abscisic acid (ABA). This study reports on the relationship between osmotic stress (e.g. the situation encountered by a shoot tip when it grows above the water surface), endogenous ABA (as measured by gas chromatography-electron capture detector) and leaf morphology in the heterophyllous aquatic plant, Hippuris vulgaris. Free ABA could not be detected in submerged shoots of H. vulgaris but in aerial shoots ABA occurred at ca. 40 ng (g fr wt)-1. When submerged shoots were osmotically stressed ABA appeared at levels of 26 to 40 ng (g fr wt)-1. These and other data support two main conclusions: (1) Osmotically stressing a submerged shoot causes the appearance of detectable levels of ABA. (2) The rise of ABA in osmotically stressed submerged shoots in turn induces a change in leaf morphology from the submerged to the aerial form. This corroborates the hypothesis that, in the natural environment, ABA levels rise in response to the osmotic stress encountered when a submerged shoot grows up through the water/air interface and that the increased ABA leads to the production of aerial-type leaves.

  11. A gate-latch-lock mechanism for hormone signalling by abscisic acid receptors

    SciTech Connect

    Melcher, Karsten; Ng, Ley-Moy; Zhou, X Edward; Soon, Fen-Fen; Xu, Yong; Suino-Powell, Kelly M; Park, Sang-Youl; Weiner, Joshua J; Fujii, Hiroaki; Chinnusamy, Viswanathan; Kovach, Amanda; Li, Jun; Wang, Yonghong; Li, Jiayang; Peterson, Francis C; Jensen, Davin R; Yong, Eu-Leong; Volkman, Brian F; Cutler, Sean R; Zhu, Jian-Kang; Xu, H Eric

    2010-01-12

    Abscisic acid (ABA) is a ubiquitous hormone that regulates plant growth, development and responses to environmental stresses. Its action is mediated by the PYR/PYL/RCAR family of START proteins, but it remains unclear how these receptors bind ABA and, in turn, how hormone binding leads to inhibition of the downstream type 2C protein phosphatase (PP2C) effectors. Here we report crystal structures of apo and ABA-bound receptors as well as a ternary PYL2-ABA-PP2C complex. The apo receptors contain an open ligand-binding pocket flanked by a gate that closes in response to ABA by way of conformational changes in two highly conserved β-loops that serve as a gate and latch. Moreover, ABA-induced closure of the gate creates a surface that enables the receptor to dock into and competitively inhibit the PP2C active site. A conserved tryptophan in the PP2C inserts directly between the gate and latch, which functions to further lock the receptor in a closed conformation. Together, our results identify a conserved gate-latch-lock mechanism underlying ABA signalling.

  12. Quantitative Proteomics Reveals the Flooding-Tolerance Mechanism in Mutant and Abscisic Acid-Treated Soybean.

    PubMed

    Yin, Xiaojian; Nishimura, Minoru; Hajika, Makita; Komatsu, Setsuko

    2016-06-03

    Flooding negatively affects the growth of soybean, and several flooding-specific stress responses have been identified; however, the mechanisms underlying flooding tolerance in soybean remain unclear. To explore the initial flooding tolerance mechanisms in soybean, flooding-tolerant mutant and abscisic acid (ABA)-treated plants were analyzed. In the mutant and ABA-treated soybeans, 146 proteins were commonly changed at the initial flooding stress. Among the identified proteins, protein synthesis-related proteins, including nascent polypeptide-associated complex and chaperonin 20, and RNA regulation-related proteins were increased in abundance both at protein and mRNA expression. However, these proteins identified at the initial flooding stress were not significantly changed during survival stages under continuous flooding. Cluster analysis indicated that glycolysis- and cell wall-related proteins, such as enolase and polygalacturonase inhibiting protein, were increased in abundance during survival stages. Furthermore, lignification of root tissue was improved even under flooding stress. Taken together, these results suggest that protein synthesis- and RNA regulation-related proteins play a key role in triggering tolerance to the initial flooding stress in soybean. Furthermore, the integrity of cell wall and balance of glycolysis might be important factors for promoting tolerance of soybean root to flooding stress during survival stages.

  13. Priming effect of abscisic acid on alkaline stress tolerance in rice (Oryza sativa L.) seedlings.

    PubMed

    Wei, Li-Xing; Lv, Bing-Sheng; Wang, Ming-Ming; Ma, Hong-Yuan; Yang, Hao-Yu; Liu, Xiao-Long; Jiang, Chang-Jie; Liang, Zheng-Wei

    2015-05-01

    Saline-alkaline stress is characterized by high salinity and high alkalinity (high pH); alkaline stress has been shown to be the primary factor inhibiting rice seedling growth. In this study, we investigated the potential priming effect of abscisic acid (ABA) on tolerance of rice seedlings to alkaline stress simulated by Na2CO3. Seedlings were pretreated with ABA at concentrations of 0 (control), 10, and 50 μM by root-drench for 24 h and then transferred to a Na2CO3 solution that did not contain ABA. Compared to control treatment, pretreatment with ABA substantially improved the survival rate of rice seedlings and increased biomass accumulation after 7 days under the alkaline condition. ABA application at 10 μM also alleviated the inhibitory effects of alkaline stress on the total root length and root surface area. Physiologically, ABA increased relative water content (RWC) and decreased cell membrane injury degree (MI) and Na(+)/K(+) ratios. In contrast, fluridone (an ABA biosynthesis inhibitor) decreased the RWC and increased MI in shoots under the alkaline conditions. These data suggest that ABA has a potent priming effect on the adaptive response to alkaline stress in rice and may be useful for improving rice growth in saline-alkaline paddy fields.

  14. 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.

  15. The Dynamics of Embolism Refilling in Abscisic Acid (ABA)-Deficient Tomato Plants

    PubMed Central

    Secchi, Francesca; Perrone, Irene; Chitarra, Walter; Zwieniecka, Anna K.; Lovisolo, Claudio; Zwieniecki, Maciej A.

    2013-01-01

    Plants are in danger of embolism formation in xylem vessels when the balance between water transport capacity and transpirational demand is compromised. To maintain this delicate balance, plants must regulate the rate of transpiration and, if necessary, restore water transport in embolized vessels. Abscisic acid (ABA) is the dominant long-distance signal responsible for plant response to stress, and it is possible that it plays a role in the embolism/refilling cycle. To test this idea, a temporal analysis of embolism and refilling dynamics, transpiration rate and starch content was performed on ABA-deficient mutant tomato plants. ABA-deficient mutants were more vulnerable to embolism formation than wild-type plants, and application of exogenous ABA had no effect on vulnerability. However, mutant plants treated with exogenous ABA had lower stomatal conductance and reduced starch content in the xylem parenchyma cells. The lower starch content could have an indirect effect on the plant’s refilling activity. The results confirm that plants with high starch content (moderately stressed mutant plants) were more likely to recover from loss of water transport capacity than plants with low starch content (mutant plants with application of exogenous ABA) or plants experiencing severe water stress. This study demonstrates that ABA most likely does not play any direct role in embolism refilling, but through the modulation of carbohydrate content, it could influence the plant’s capacity for refilling. PMID:23263667

  16. Dissection of the transcriptional regulation of grape ASR and response to glucose and abscisic acid.

    PubMed

    Saumonneau, Amélie; Laloi, Maryse; Lallemand, Magali; Rabot, Amélie; Atanassova, Rossitza

    2012-02-01

    Despite the fact that the precise physiological function of ASRs [abscisic acid (ABA), stress, ripening] remains unknown, they have been suggested to play a dual role in the plant response to environmental cues, as highly hydrophilic proteins for direct protection, as well as transcription factors involved in the regulation of gene expression. To investigate further the biological positioning of grape ASR in the hormonal and metabolic signal network, three promoters corresponding to its cDNA were isolated and submited to a detailed in silico and functional analysis. The results obtained provided evidence for the allelic polymorphism of the grape ASR gene, the organ-preferential expression conferred on the GUS reporter gene, and the specific phloem tissue localization revealed by in situ hybridization. The study of glucose and ABA signalling in its transcriptional control, by transfection of grape protoplasts using the dual luciferase system, revealed the complexity of ASR gene expression regulation. A model was proposed allowing a discussion of the place of ASR in the fine tuning of hormonal and metabolic signalling involved in the integration of environmental cues by the plant organism.

  17. Abscisic acid regulation of DC8, a carrot embryonic gene. [Daucus carota

    SciTech Connect

    Hatzopoulos, P.; Fong, F.; Sung, Z.R. Texas A M Univ., College Station )

    1990-10-01

    DC8 encodes a hydrophylic 66 kilodalton protein located in the cytoplasm and cell walls of carrot (Daucus carota) embryo and endosperm. During somatic embryogenesis, the levels of DC8 mRNA and protein begin to increase 5 days after removal of auxin. To study the role of abscisic acid (ABA) in the regulation of DC8 gene, fluridone, 1-methyl-3-phenyl,-5(3-trifluoro-methyl-phenyl)-4(1H)-pyridinone, was used to inhibit the endogenous ABA content of the embryos. Fluridone, 50 micrograms per milliliter, effectively inhibits the accumulation of ABA in globular-tage embryos. Western and Northern analysis show that when fluridone is added to the culture medium DC8 protein and mRNA decrease to very low levels. ABA added to fluridone supplemented culture media restores the DC8 protein and mRNA to control levels. Globular-stage embryos contain 0.9 to 1.4 {times} 10{sup {minus}7} molar ABA while 10{sup {minus}6} molar exogenously supplied ABA is the optimal concentration for restoration of DC8 protein accumulation in fluridone-treated embryos. The mRNA level is increased after 15 minutes of ABA addition and reaches maximal levels by 60 minutes. Evidence is presented that, unlike other ABA-regulated genes, DC8 is not induced in nonembryonic tissues via desiccation nor addition of ABA.

  18. Drought-Induced Increases in Abscisic Acid Levels in the Root Apex of Sunflower 1

    PubMed Central

    Robertson, J. Mason; Pharis, Richard P.; Huang, Yan Y.; Reid, David M.; Yeung, Edward C.

    1985-01-01

    Abscisic acid (ABA) levels in 3-mm apical root segments of slowly droughted sunflower plants (Helianthus annuus L. cv Russian Giant) were analyzed as the methyl ester by selected ion monitoring gas chromatography-mass spectrometry using characteristic ions. An internal standard, hexadeuterated ABA (d6ABA) was used for quantitative analysis. Sunflower seedlings, grown in aeroponic chambers, were slowly droughted over a 7-day period. Drought stress increased ABA levels in the root tips at 24, 72, and 168 hour sample times. Control plants had 57 to 106 nanograms per gram ABA dry weight in the root tips (leaf water potential, −0.35 to −0.42 megapascals). The greatest increase in ABA, about 20-fold, was found after 72 hours of drought (leaf water potential, −1.34 to −1.47 megapascals). Levels of ABA also increased (about 7− to 54-fold) in 3-mm apical root segments which were excised and then allowed to dessicate for 1 hour at room temperature. PMID:16664535

  19. Influence of cadmium on water relations, stomatal resistance, and abscisic acid content in expanding bean leaves

    SciTech Connect

    Poschenrieder, C.; Gunse, B.; Barcelo, J. )

    1989-08-01

    Ten day old bush bean plants (Phaseolus vulgaris L. cv Contender) were used to analyze the effects of 3 micromolar Cd on the time courses of expansion growth, dry weight, leaf water relations, stomatal resistance, and abscisic acid (ABA) levels in roots and leaves. Control and Cd-treated plants were grown for 144 hours in nutrient solution. Samples were taken at 24 hour intervals. At the 96 and 144 hour harvests, additional measurements were made on excised leaves which were allowed to dry for 2 hours. From the 48 hour harvest, Cd-treated plants showed lower leaf relative water contents and higher stomatal resistances than controls. At the same time, root and leaf expansion growth, but not dry weight, was significantly reduced. The turgor potentials of leaves from Cd-treated plants were nonsignificantly higher than those of control leaves. A significant increase (almost 400%) of the leaf ABA concentration was detected after 120 hours exposure to Cd. But Cd was found to inhibit ABA accumulation during drying of excised leaves. It is concluded that Cd-induced decrease of expansion growth is not due to turgor decrease. The possible mechanisms of Cd-induced stomatal closure are discussed.

  20. Putting the brakes on: abscisic acid as a central environmental regulator of stomatal development.

    PubMed

    Chater, Caspar C C; Oliver, James; Casson, Stuart; Gray, Julie E

    2014-04-01

    Stomata are produced by a controlled series of epidermal cell divisions. The molecular underpinnings of this process are becoming well understood, but mechanisms that determine plasticity of stomatal patterning to many exogenous and environmental cues remain less clear. Light quantity and quality, vapour pressure deficit, soil water content, and CO2 concentration are detected by the plant, and new leaves adapt their stomatal densities accordingly. Mature leaves detect these environmental signals and relay messages to immature leaves to tell them how to adapt and grow. Stomata on mature leaves may act as stress signal-sensing and transduction centres, locally by aperture adjustment, and at long distance by optimizing stomatal density to maximize future carbon gain while minimizing water loss. Although mechanisms of stomatal aperture responses are well characterized, the pathways by which mature stomata integrate environmental signals to control immature epidermal cell fate, and ultimately stomatal density, are not. Here we evaluate current understanding of the latter through the influence of the former. We argue that mature stomata, as key portals by which plants coordinate their carbon and water relations, are controlled by abscisic acid (ABA), both metabolically and hydraulically, and that ABA is also a core regulator of environmentally determined stomatal development.

  1. Abscisic acid in soil facilitates community succession in three forests in China.

    PubMed

    Zhao, Houben; Peng, Shaolin; Chen, Zhuoquan; Wu, Zhongmin; Zhou, Guangyi; Wang, Xu; Qiu, Zhijun

    2011-07-01

    Plants release secondary metabolites into the soil that change the chemical environment around them. Exogenous abscisic acid (ABA) is an important allelochemical whose role in successional trajectories has not been examined. We hypothesized that ABA can accumulate in the soil through successional processes and have an influence on forest dynamics. To this end, we investigated the distribution of ABA in forest communities from early to late successional stages and the response of dominant species to the gradient of ABA concentrations in three types of forests from northern to southern China. Concentrations of ABA in the soils of three forest types increased from early to late successional stages. Pioneer species' litters had the lowest ABA content, and their seed germination and seedling early growth were the most sensitive to the inhibitory effect of ABA. Mid- and late-successional species had a much higher ABA content in fallen leaves than pioneer species, and their seed germination and seedling early growth were inhibited by higher concentrations of ABA than pioneers. Late-successional species showed little response to the highest ABA concentration, possibly due to their large seed size. The results suggest that ABA accumulates in the soil as community succession proceeds. Sensitivity to ABA in the early stages, associated with other characteristics, may result in pioneer species losing their advantage in competition with late-successional species in an increasingly high ABA concentration environment, and being replaced by ABA-tolerant, late-successional species.

  2. Autocrine abscisic acid plays a key role in quartz-induced macrophage activation.

    PubMed

    Magnone, Mirko; Sturla, Laura; Jacchetti, Emanuela; Scarfì, Sonia; Bruzzone, Santina; Usai, Cesare; Guida, Lucrezia; Salis, Annalisa; Damonte, Gianluca; De Flora, Antonio; Zocchi, Elena

    2012-03-01

    Inhalation of quartz induces silicosis, a lung disease where alveolar macrophages release inflammatory mediators, including prostaglandin-E(2) (PGE(2)) and tumor necrosis factor α (TNF-α). Here we report the pivotal role of abscisic acid (ABA), a recently discovered human inflammatory hormone, in silica-induced activation of murine RAW264.7 macrophages and of rat alveolar macrophages (AMs). Stimulation of both RAW264.7 cells and AMs with quartz induced a significant increase of ABA release (5- and 10-fold, respectively), compared to untreated cells. In RAW264.7 cells, autocrine ABA released after quartz stimulation sequentially activates the plasma membrane receptor LANCL2 and NADPH oxidase, generating a Ca(2+) influx resulting in NFκ B nuclear translocation and PGE(2) and TNF-α release (3-, 2-, and 3.5-fold increase, respectively, compared to control, unstimulated cells). Quartz-stimulated RAW264.7 cells silenced for LANCL2 or preincubated with a monoclonal antibody against ABA show an almost complete inhibition of NFκ B nuclear translocation and PGE(2) and TNF-α release compared to controls electroporated with a scramble oligonucleotide or preincubated with an unrelated antibody. AMs showed similar early and late ABA-induced responses as RAW264.7 cells. These findings identify ABA and LANCL2 as key mediators in quartz-induced inflammation, providing possible new targets for antisilicotic therapy.

  3. Abscisic acid substantially inhibits senescence of cucumber plants (Cucumis sativus) grown under low nitrogen conditions.

    PubMed

    Oka, Mariko; Shimoda, Yousuke; Sato, Naoko; Inoue, Junya; Yamazaki, Teru; Shimomura, Norihiro; Fujiyama, Hideyasu

    2012-05-15

    Low nitrogen (N) availability such as that found in both dry land and tropical regions limits plant growth and development. The relationship between the level of abscisic acid (ABA) in a plant and its growth under low-N conditions was investigated. The level of ABA in cucumber (Cucumis sativus) plants under low-N conditions was significantly higher at 10 and 20 d after transplantation compared with that under sufficient-N conditions. Chlorophyll was preserved in the aerial parts of cucumber plants grown under low-N conditions in the presence of ABA, while there was no significant difference between control plants and ABA-applied plants under sufficient-N conditions. ABA suppressed the reduction of chlorophyll biosynthesis under low-N conditions but not under sufficient-N conditions. On the other hand, ABA decreased the expression of the chlorophyll degradation gene in older cucumber plants grown under both conditions. In addition, transcript and protein levels of a gene encoding a chlorophyll a/b binding protein were positively correlated with ABA concentration under low-N conditions. The chloroplasts in control plants were round, and the stack of thylakoid membranes was reduced compared with that of plants treated with ABA 10(-5) M. These results strongly suggest that ABA is accumulated in cucumber plants grown under low-N conditions and that accumulated ABA promotes chlorophyll biosynthesis and inhibits its degradation in those plants.

  4. Calcium specificity signaling mechanisms in abscisic acid signal transduction in Arabidopsis guard cells

    PubMed Central

    Brandt, Benjamin; Munemasa, Shintaro; Wang, Cun; Nguyen, Desiree; Yong, Taiming; Yang, Paul G; Poretsky, Elly; Belknap, Thomas F; Waadt, Rainer; Alemán, Fernando; Schroeder, Julian I

    2015-01-01

    A central question is how specificity in cellular responses to the eukaryotic second messenger Ca2+ is achieved. Plant guard cells, that form stomatal pores for gas exchange, provide a powerful system for in depth investigation of Ca2+-signaling specificity in plants. In intact guard cells, abscisic acid (ABA) enhances (primes) the Ca2+-sensitivity of downstream signaling events that result in activation of S-type anion channels during stomatal closure, providing a specificity mechanism in Ca2+-signaling. However, the underlying genetic and biochemical mechanisms remain unknown. Here we show impairment of ABA signal transduction in stomata of calcium-dependent protein kinase quadruple mutant plants. Interestingly, protein phosphatase 2Cs prevent non-specific Ca2+-signaling. Moreover, we demonstrate an unexpected interdependence of the Ca2+-dependent and Ca2+-independent ABA-signaling branches and the in planta requirement of simultaneous phosphorylation at two key phosphorylation sites in SLAC1. We identify novel mechanisms ensuring specificity and robustness within stomatal Ca2+-signaling on a cellular, genetic, and biochemical level. DOI: http://dx.doi.org/10.7554/eLife.03599.001 PMID:26192964

  5. The pivotal role of abscisic acid signaling during transition from seed maturation to germination.

    PubMed

    Yan, An; Chen, Zhong

    2016-11-23

    Seed maturation and germination are two continuous developmental processes that link two distinct generations in spermatophytes; the precise genetic control of these two processes is, therefore, crucially important for the survival of the next generation. Pieces of experimental evidence accumulated so far indicate that a concerted action of endogenous signals and environmental cues is required to govern these processes. Plant hormone abscisic acid (ABA) has been suggested to play a predominant role in directing seed maturation and maintaining seed dormancy under unfavorable environmental conditions until antagonized by gibberellins (GA) and certain environmental cues to allow the commencement of seed germination when environmental conditions are favorable; therefore, the balance of ABA and GA is a major determinant of the timing of seed germination. Due to the advent of new technologies and system biology approaches, molecular studies are beginning to draw a picture of the sophisticated genetic network that drives seed maturation during the past decade, though the picture is still incomplete and many details are missing. In this review, we summarize recent advances in ABA signaling pathway in the regulation of seed maturation as well as the transition from seed maturation to germination, and highlight the importance of system biology approaches in the study of seed maturation.

  6. The Effect of Abscisic Acid on the Freezing Tolerance of Callus Cultures of Lotus corniculatus L.

    PubMed

    Keith, C N; McKersie, B D

    1986-03-01

    The effects of growth temperature (2 degrees C and 24 degrees C), abscisic acid (ABA) concentration, duration of exposure to ABA, and light were assessed for their ability to induce acclimation to freezing temperatures in callus cultures of Lotus corniculatus L. cv Leo, a perennial forage legume. The maximal expression of freezing tolerance was achieved on B(5) media containing 10(-5) molar ABA, at 24 degrees C for 7 or 14 days. Under these culture conditions, the freezing tolerance of the callus approximated that observed in field grown plants. In contrast, low temperatures (2 degrees C) induced only a limited degree of freezing tolerance in these cultures. Viability was assessed by tetrazolium reduction and by regrowth of the callus. The two assays often differed in their estimates of absolute freezing tolerance. Regression analysis of the temperature profile suggested that there may be two or more distinct populations of cells differing in freezing tolerance, which may have contributed to the variability between viability assays.

  7. Designed abscisic acid analogs as antagonists of PYL-PP2C receptor interactions.

    PubMed

    Takeuchi, Jun; Okamoto, Masanori; Akiyama, Tomonori; Muto, Takuya; Yajima, Shunsuke; Sue, Masayuki; Seo, Mitsunori; Kanno, Yuri; Kamo, Tsunashi; Endo, Akira; Nambara, Eiji; Hirai, Nobuhiro; Ohnishi, Toshiyuki; Cutler, Sean R; Todoroki, Yasushi

    2014-06-01

    The plant stress hormone abscisic acid (ABA) is critical for several abiotic stress responses. ABA signaling is normally repressed by group-A protein phosphatases 2C (PP2Cs), but stress-induced ABA binds Arabidopsis PYR/PYL/RCAR (PYL) receptors, which then bind and inhibit PP2Cs. X-ray structures of several receptor-ABA complexes revealed a tunnel above ABA's 3' ring CH that opens at the PP2C binding interface. Here, ABA analogs with sufficiently long 3' alkyl chains were predicted to traverse this tunnel and block PYL-PP2C interactions. To test this, a series of 3'-alkylsulfanyl ABAs were synthesized with different alkyl chain lengths. Physiological, biochemical and structural analyses revealed that a six-carbon alkyl substitution produced a potent ABA antagonist that was sufficiently active to block multiple stress-induced ABA responses in vivo. This study provides a new approach for the design of ABA analogs, and the results validated structure-based design for this target class.

  8. Karrikins delay soybean seed germination by mediating abscisic acid and gibberellin biogenesis under shaded conditions

    PubMed Central

    Meng, Yongjie; Chen, Feng; Shuai, Haiwei; Luo, Xiaofeng; Ding, Jun; Tang, Shengwen; Xu, Shuanshuan; Liu, Jianwei; Liu, Weiguo; Du, Junbo; Liu, Jiang; Yang, Feng; Sun, Xin; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Shu, Kai; Yang, Wenyu

    2016-01-01

    Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interestingly, KAR only retarded soybean seed germination under shaded conditions, rather than under dark and white light conditions, which differs from in Arabidopsis. Phytohormone quantification showed that KAR enhanced ABA biogenesis while impairing GA biosynthesis during the seed imbibition process, and subsequently, the ratio of active GA4 to ABA was significantly reduced. Further qRT-PCR analysis showed that the transcription pattern of genes involved in ABA and GA metabolic pathways are consistent with the hormonal measurements. Finally, fluridone, an ABA biogenesis inhibitor, remarkably rescued the delayed-germination phenotype of KAR-treatment; and paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Taken together, these evidences suggest that KAR inhibit soybean seed germination by mediating the ratio between GA and ABA biogenesis. PMID:26902640

  9. Influence of abscisic acid and sucrose on somatic embryogenesis in Cactus Copiapoa tenuissima Ritt. forma mostruosa.

    PubMed

    Lema-Rumińska, J; Goncerzewicz, K; Gabriel, M

    2013-01-01

    Having produced the embryos of cactus Copiapoa tenuissima Ritt. forma monstruosa at the globular stage and callus, we investigated the effect of abscisic acid (ABA) in the following concentrations: 0, 0.1, 1, 10, and 100  μ M on successive stages of direct (DSE) and indirect somatic embryogenesis (ISE). In the indirect somatic embryogenesis process we also investigated a combined effect of ABA (0, 0.1, 1  μ M) and sucrose (1, 3, 5%). The results showed that a low concentration of ABA (0-1  μ M) stimulates the elongation of embryos at the globular stage and the number of correct embryos in direct somatic embryogenesis, while a high ABA concentration (10-100  μ M) results in growth inhibition and turgor pressure loss of somatic embryos. The indirect somatic embryogenesis study in this cactus suggests that lower ABA concentrations enhance the increase in calli fresh weight, while a high concentration of 10  μ M ABA or more changes calli color and decreases its proliferation rate. However, in the case of indirect somatic embryogenesis, ABA had no effect on the number of somatic embryos and their maturation. Nevertheless, we found a positive effect of sucrose concentration for both the number of somatic embryos and the increase in calli fresh weight.

  10. Abscisic acid, xanthoxin and violaxanthin in the caps of gravistimulated maize roots

    NASA Technical Reports Server (NTRS)

    Feldman, L. J.; Arroyave, N. J.; Sun, P. S.

    1985-01-01

    The occurrence and distribution of abscisic acid (ABA), xanthoxin (Xa) and the carotenoid violaxanthin (Va) were investigated in root tips of maize (Zea mays L. cv. Merit). In roots grown in the dark, Va and ABA were present in relatively high amounts in the root cap and in low amounts in the adjacent terminal 1.5 mm of the root. Xanthoxin was present in equal concentrations in both regions. In roots exposed to light, the ABA distribution was reversed, with relatively low levels in the root cap and high levels in the adjacent 1.5-mm segment. Light also caused a decrease in Va in both regions of the root and an increase in Xa, especially in the cap. In the maize cultivar used for this work, light is necessary for gravitropic curving. This response occurs within the same time frame as the light-induced ABA redistribution as well as the changes in the levels of Va and Xa. These data are consistent with a role for ABA in root gravitropism and support the proposal that Xa may arise from the turnover of Va.

  11. Diverse functional interactions between nitric oxide and abscisic acid in plant development and responses to stress.

    PubMed

    León, José; Castillo, Mari Cruz; Coego, Alberto; Lozano-Juste, Jorge; Mir, Ricardo

    2014-03-01

    The extensive support for abscisic acid (ABA) involvement in the complex regulatory networks controlling stress responses and development in plants contrasts with the relatively recent role assigned to nitric oxide (NO). Because treatment with exogenous ABA leads to enhanced production of NO, it has been widely considered that NO participates downstream of ABA in controlling processes such as stomata movement, seed dormancy, and germination. However, data on leaf senescence and responses to stress suggest that the functional interaction between ABA and NO is more complex than previously thought, including not only cooperation but also antagonism. The functional relationship is probably determined by several factors including the time- and place-dependent pattern of accumulation of both molecules, the threshold levels, and the regulatory factors important for perception. These factors will determine the actions exerted by each regulator. Here, several examples of well-documented functional interactions between NO and ABA are analysed in light of the most recent reported data on seed dormancy and germination, stomata movements, leaf senescence, and responses to abiotic and biotic stresses.

  12. Tetraploid Rangpur lime rootstock increases drought tolerance via enhanced constitutive root abscisic acid production.

    PubMed

    Allario, Thierry; Brumos, Javier; Colmenero-Flores, Jose M; Iglesias, Domingo J; Pina, Jose A; Navarro, Luis; Talon, Manuel; Ollitrault, Patrick; Morillon, Raphaël

    2013-04-01

    Whole-genome duplication, or polyploidy, is common in many plant species and often leads to better adaptation to adverse environmental condition. However, little is known about the physiological and molecular determinants underlying adaptation. We examined the drought tolerance in diploid (2x) and autotetraploid (4x) clones of Rangpur lime (Citrus limonia) rootstocks grafted with 2x Valencia Delta sweet orange (Citrus sinensis) scions, named V/2xRL and V/4xRL, respectively. Physiological experiments to study root-shoot communication associated with gene expression studies in roots and leaves were performed. V/4xRL was much more tolerant to water deficit than V/2xRL. Gene expression analysis in leaves and roots showed that more genes related to the response to water stress were differentially expressed in V/2xRL than in V/4xRL. Prior to the stress, when comparing V/4xRL to V/2xRL, V/4xRL leaves had lower stomatal conductance and greater abscisic acid (ABA) content. In roots, ABA content was higher in V/4xRL and was associated to a greater expression of drought responsive genes, including CsNCED1, a pivotal regulatory gene of ABA biosynthesis. We conclude that tetraploidy modifies the expression of genes in Rangpur lime citrus roots to regulate long-distance ABA signalling and adaptation to stress.

  13. Dynamic changes in the transcriptome of Populus hopeiensis in response to abscisic acid

    PubMed Central

    Chen, Zhong; Ji, Lexiang; Wang, Jia; Jin, Jinpu; Yang, Xiaoyu; Rao, Pian; Gao, Kai; Liao, Weihua; Ye, Meixia; An, Xinmin

    2017-01-01

    Abscisic acid (ABA) plays a fundamental role in plant response and adaptation to abiotic stresses, such as drought, high salinity and low temperature. Populus hopeiensis exhibits exceptional tolerance to water-deficit environments and is therefore an excellent choice for studying drought tolerance in trees. This study provides a global view of transcriptome dynamics in P. hopeiensis in response to exogenous ABA using Illumina RNA-sequencing. Endogenous ABA content increased and reached a peak at 8 h after ABA treatment and then significantly decreased at latter time points. Differential expression analysis and Gene ontology enrichment revealed that the number of transcripts exhibited significant increase during the first 8 hours after ABA treatment, which then significantly decreased at 12 and 24 h. Transcription factors (TFs) analysis showed that six different patterns were observed based on the expression of the six TFs families (AP2/ERF, NAC, MYB, MYB-related, bZIP and WRKY) and the majority of differentially expressed TFs increased rapidly after ABA treatment. This study provides a robust resource for investigating the functions of genes induced by ABA and will help to develop a better understanding of the molecular regulatory mechanism in response to drought in poplar. PMID:28198429

  14. Thiol-based Redox Proteins in Brassica napus Guard Cell Abscisic Acid and Methyl Jasmonate Signaling

    PubMed Central

    Zhu, Mengmeng; Zhu, Ning; Song, Wen-yuan; Harmon, Alice C.; Assmann, Sarah M.; Chen, Sixue

    2014-01-01

    SUMMARY Reversibly oxidized cysteine sulfhydryl groups serve as redox sensors or targets of redox sensing that are important in different physiological processes. Little is known, however, about redox sensitive proteins in guard cells and how they function in stomatal signaling. In this study, Brassica napus guard cell proteins altered by redox in response to abscisic acid (ABA) or methyl jasmonate (MeJA) were identified by complementary proteomics approaches, saturation differential in-gel electrophoresis (DIGE) and isotope-coded affinity tag (ICAT). In total, 65 and 118 potential redox responsive proteins were identified in ABA and MeJA treated guard cells, respectively. All the proteins contain at least one cysteine, and over half of them are predicted to form intra-molecular disulfide bonds. Most of the proteins fall into the functional groups of energy, stress and defense, and metabolism. Based on the peptide sequences identified by mass spectrometry, 30 proteins were common to ABA and MeJA treated samples. A total of 44 cysteines was mapped in all the identified proteins, and their levels of redox sensitivity were quantified. Two of the proteins, a SNRK2 kinase and an isopropylmalate dehydrogenase were confirmed to be redox regulated and involved in stomatal movement. This study creates an inventory of potential redox switches, and highlights a protein redox regulatory mechanism in guard cell ABA and MeJA signal transduction. PMID:24580573

  15. The role of abscisic acid and water stress in root herbivore-induced leaf resistance.

    PubMed

    Erb, Matthias; Köllner, Tobias G; Degenhardt, Jörg; Zwahlen, Claudia; Hibbard, Bruce E; Turlings, Ted C J

    2011-01-01

    • Herbivore-induced systemic resistance occurs in many plants and is commonly assumed to be adaptive. The mechanisms triggered by leaf-herbivores that lead to systemic resistance are largely understood, but it remains unknown how and why root herbivory also increases resistance in leaves. • To resolve this, we investigated the mechanism by which the root herbivore Diabrotica virgifera induces resistance against lepidopteran herbivores in the leaves of Zea mays. • Diabrotica virgifera infested plants suffered less aboveground herbivory in the field and showed reduced growth of Spodoptera littoralis caterpillars in the laboratory. Root herbivory did not lead to a jasmonate-dependent response in the leaves, but specifically triggered water loss and abscisic acid (ABA) accumulation. The induction of ABA by itself was partly responsible for the induction of leaf defenses, but not for the resistance against S. littoralis. Root-herbivore induced hydraulic changes in the leaves, however, were crucial for the increase in insect resistance. • We conclude that the induced leaf resistance after root feeding is the result of hydraulic changes, which reduce the quality of the leaves for chewing herbivores. This finding calls into question whether root-herbivore induced leaf-resistance is an evolved response.

  16. Fern and Lycophyte Guard Cells Do Not Respond to Endogenous Abscisic Acid

    PubMed Central

    McAdam, Scott A.M.; Brodribb, Timothy J.

    2012-01-01

    Stomatal guard cells regulate plant photosynthesis and transpiration. Central to the control of seed plant stomatal movement is the phytohormone abscisic acid (ABA); however, differences in the sensitivity of guard cells to this ubiquitous chemical have been reported across land plant lineages. Using a phylogenetic approach to investigate guard cell control, we examined the diversity of stomatal responses to endogenous ABA and leaf water potential during water stress. We show that although all species respond similarly to leaf water deficit in terms of enhanced levels of ABA and closed stomata, the function of fern and lycophyte stomata diverged strongly from seed plant species upon rehydration. When instantaneously rehydrated from a water-stressed state, fern and lycophyte stomata rapidly reopened to predrought levels despite the high levels of endogenous ABA in the leaf. In seed plants under the same conditions, high levels of ABA in the leaf prevented rapid reopening of stomata. We conclude that endogenous ABA synthesized by ferns and lycophytes plays little role in the regulation of transpiration, with stomata passively responsive to leaf water potential. These results support a gradualistic model of stomatal control evolution, offering opportunities for molecular and guard cell biochemical studies to gain further insights into stomatal control. PMID:22517320

  17. Agrochemical control of plant water use using engineered abscisic acid receptors.

    PubMed

    Park, Sang-Youl; Peterson, Francis C; Mosquna, Assaf; Yao, Jin; Volkman, Brian F; Cutler, Sean R

    2015-04-23

    Rising temperatures and lessening fresh water supplies are threatening agricultural productivity and have motivated efforts to improve plant water use and drought tolerance. During water deficit, plants produce elevated levels of abscisic acid (ABA), which improves water consumption and stress tolerance by controlling guard cell aperture and other protective responses. One attractive strategy for controlling water use is to develop compounds that activate ABA receptors, but agonists approved for use have yet to be developed. In principle, an engineered ABA receptor that can be activated by an existing agrochemical could achieve this goal. Here we describe a variant of the ABA receptor PYRABACTIN RESISTANCE 1 (PYR1) that possesses nanomolar sensitivity to the agrochemical mandipropamid and demonstrate its efficacy for controlling ABA responses and drought tolerance in transgenic plants. Furthermore, crystallographic studies provide a mechanistic basis for its activity and demonstrate the relative ease with which the PYR1 ligand-binding pocket can be altered to accommodate new ligands. Thus, we have successfully repurposed an agrochemical for a new application using receptor engineering. We anticipate that this strategy will be applied to other plant receptors and represents a new avenue for crop improvement.

  18. The dynamics of embolism refilling in abscisic acid (ABA)-deficient tomato plants.

    PubMed

    Secchi, Francesca; Perrone, Irene; Chitarra, Walter; Zwieniecka, Anna K; Lovisolo, Claudio; Zwieniecki, Maciej A

    2012-12-24

    Plants are in danger of embolism formation in xylem vessels when the balance between water transport capacity and transpirational demand is compromised. To maintain this delicate balance, plants must regulate the rate of transpiration and, if necessary, restore water transport in embolized vessels. Abscisic acid (ABA) is the dominant long-distance signal responsible for plant response to stress, and it is possible that it plays a role in the embolism/refilling cycle. To test this idea, a temporal analysis of embolism and refilling dynamics, transpiration rate and starch content was performed on ABA-deficient mutant tomato plants. ABA-deficient mutants were more vulnerable to embolism formation than wild-type plants, and application of exogenous ABA had no effect on vulnerability. However, mutant plants treated with exogenous ABA had lower stomatal conductance and reduced starch content in the xylem parenchyma cells. The lower starch content could have an indirect effect on the plant's refilling activity. The results confirm that plants with high starch content (moderately stressed mutant plants) were more likely to recover from loss of water transport capacity than plants with low starch content (mutant plants with application of exogenous ABA) or plants experiencing severe water stress. This study demonstrates that ABA most likely does not play any direct role in embolism refilling, but through the modulation of carbohydrate content, it could influence the plant's capacity for refilling.

  19. Abscisic acid mediates a divergence in the drought response of two conifers.

    PubMed

    Brodribb, Timothy J; McAdam, Scott A M

    2013-07-01

    During water stress, stomatal closure occurs as water tension and levels of abscisic acid (ABA) increase in the leaf, but the interaction between these two drivers of stomatal aperture is poorly understood. We investigate the dynamics of water potential, ABA, and stomatal conductance during the imposition of water stress on two drought-tolerant conifer species with contrasting stomatal behavior. Rapid rehydration of excised shoots was used as a means of differentiating the direct influences of ABA and water potential on stomatal closure. Pinus radiata (Pinaceae) was found to exhibit ABA-driven stomatal closure during water stress, resulting in strongly isohydric regulation of water loss. By contrast, stomatal closure in Callitris rhomboidea (Cupressaceae) was initiated by elevated foliar ABA, but sustained water stress saw a marked decline in ABA levels and a shift to water potential-driven stomatal closure. The transition from ABA to water potential as the primary driver of stomatal aperture allowed C. rhomboidea to rapidly recover gas exchange after water-stressed plants were rewatered, and was associated with a strongly anisohydric regulation of water loss. These two contrasting mechanisms of stomatal regulation function in combination with xylem vulnerability to produce highly divergent strategies of water management. Species-specific ABA dynamics are proposed as a central component of drought survival and ecology.

  20. Abscisic Acid Mediates a Divergence in the Drought Response of Two Conifers1[W][OA

    PubMed Central

    Brodribb, Timothy J.; McAdam, Scott A.M.

    2013-01-01

    During water stress, stomatal closure occurs as water tension and levels of abscisic acid (ABA) increase in the leaf, but the interaction between these two drivers of stomatal aperture is poorly understood. We investigate the dynamics of water potential, ABA, and stomatal conductance during the imposition of water stress on two drought-tolerant conifer species with contrasting stomatal behavior. Rapid rehydration of excised shoots was used as a means of differentiating the direct influences of ABA and water potential on stomatal closure. Pinus radiata (Pinaceae) was found to exhibit ABA-driven stomatal closure during water stress, resulting in strongly isohydric regulation of water loss. By contrast, stomatal closure in Callitris rhomboidea (Cupressaceae) was initiated by elevated foliar ABA, but sustained water stress saw a marked decline in ABA levels and a shift to water potential-driven stomatal closure. The transition from ABA to water potential as the primary driver of stomatal aperture allowed C. rhomboidea to rapidly recover gas exchange after water-stressed plants were rewatered, and was associated with a strongly anisohydric regulation of water loss. These two contrasting mechanisms of stomatal regulation function in combination with xylem vulnerability to produce highly divergent strategies of water management. Species-specific ABA dynamics are proposed as a central component of drought survival and ecology. PMID:23709665

  1. A Nuclear Factor Regulates Abscisic Acid Responses in Arabidopsis1[W][OA

    PubMed Central

    Kim, Min Jung; Shin, Ryoung; Schachtman, Daniel P.

    2009-01-01

    Abscisic acid (ABA) is a plant hormone that regulates plant growth as well as stress responses. In this study, we identified and characterized a new Arabidopsis (Arabidopsis thaliana) protein, Nuclear Protein X1 (NPX1), which was up-regulated by stress and treatment with exogenous ABA. Stomatal closure, seed germination, and primary root growth are well-known ABA responses that were less sensitive to ABA in NPX1-overexpressing plants. NPX1-overexpressing plants were more drought sensitive, and the changes in response to drought were due to the altered guard cell sensitivity to ABA in transgenic plants and not to a lack of ABA production. The nuclear localization of NPX1 correlated with changes in the expression of genes involved in ABA biosynthesis and ABA signal transduction. To understand the function of NPX1, we searched for interacting proteins and found that an ABA-inducible NAC transcription factor, TIP, interacted with NPX1. Based on the whole plant phenotypes, we hypothesized that NPX1 acts as a transcriptional repressor, and this was demonstrated in yeast, where we showed that TIP was repressed by NPX1. Our results indicate that the previously unknown protein NPX1 acts as a negative regulator in plant response to changes in environmental conditions through the control of ABA-regulated gene expression. The characterization of this factor enhances our understanding of guard cell function and the mechanisms that plants use to modulate water loss from leaves under drought conditions. PMID:19759343

  2. 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.

  3. Karrikins delay soybean seed germination by mediating abscisic acid and gibberellin biogenesis under shaded conditions.

    PubMed

    Meng, Yongjie; Chen, Feng; Shuai, Haiwei; Luo, Xiaofeng; Ding, Jun; Tang, Shengwen; Xu, Shuanshuan; Liu, Jianwei; Liu, Weiguo; Du, Junbo; Liu, Jiang; Yang, Feng; Sun, Xin; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Shu, Kai; Yang, Wenyu

    2016-02-23

    Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interestingly, KAR only retarded soybean seed germination under shaded conditions, rather than under dark and white light conditions, which differs from in Arabidopsis. Phytohormone quantification showed that KAR enhanced ABA biogenesis while impairing GA biosynthesis during the seed imbibition process, and subsequently, the ratio of active GA4 to ABA was significantly reduced. Further qRT-PCR analysis showed that the transcription pattern of genes involved in ABA and GA metabolic pathways are consistent with the hormonal measurements. Finally, fluridone, an ABA biogenesis inhibitor, remarkably rescued the delayed-germination phenotype of KAR-treatment; and paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Taken together, these evidences suggest that KAR inhibit soybean seed germination by mediating the ratio between GA and ABA biogenesis.

  4. Abscisic acid stimulated ripening and gene expression in berry skins of the Cabernet Sauvignon grape.

    PubMed

    Koyama, Kazuya; Sadamatsu, Keiko; Goto-Yamamoto, Nami

    2010-08-01

    We investigated the effect of exogenous abscisic acid (ABA) application on the transcriptome as well as the phenolic profiles in the skins of Vitis vinifera cv. Cabernet Sauvignon grape berries grown on the vine and cultured in vitro. ABA application rapidly induced the accumulation of anthocyanin and flavonol. Correlatively, the structural genes in the phenylpropanoid and flavonoid pathways, their transcriptional regulators, as well as genes considered to be involved in the acylation and transport of anthocyanin into the vacuole, were upregulated by ABA treatment. The Genechip analysis showed that the ABA treatment significantly up- or downregulated a total of 345 and 1,482 transcripts in the skins of berries grown on the vine and cultured in vitro, respectively. Exogenous ABA modulated the transcripts associated with osmotic responses, stress responses, cell wall modification, auxin and ethylene metabolism and responses, in addition to the induction of anthocyanin biosynthetic genes, and reduced those associated with photosynthesis; approximately half of these transcripts were identical to the previously reported ripening-specific genes.

  5. Fern and lycophyte guard cells do not respond to endogenous abscisic acid.

    PubMed

    McAdam, Scott A M; Brodribb, Timothy J

    2012-04-01

    Stomatal guard cells regulate plant photosynthesis and transpiration. Central to the control of seed plant stomatal movement is the phytohormone abscisic acid (ABA); however, differences in the sensitivity of guard cells to this ubiquitous chemical have been reported across land plant lineages. Using a phylogenetic approach to investigate guard cell control, we examined the diversity of stomatal responses to endogenous ABA and leaf water potential during water stress. We show that although all species respond similarly to leaf water deficit in terms of enhanced levels of ABA and closed stomata, the function of fern and lycophyte stomata diverged strongly from seed plant species upon rehydration. When instantaneously rehydrated from a water-stressed state, fern and lycophyte stomata rapidly reopened to predrought levels despite the high levels of endogenous ABA in the leaf. In seed plants under the same conditions, high levels of ABA in the leaf prevented rapid reopening of stomata. We conclude that endogenous ABA synthesized by ferns and lycophytes plays little role in the regulation of transpiration, with stomata passively responsive to leaf water potential. These results support a gradualistic model of stomatal control evolution, offering opportunities for molecular and guard cell biochemical studies to gain further insights into stomatal control.

  6. Two Transduction Pathways Mediate Rapid Effects of Abscisic Acid in Commelina Guard Cells.

    PubMed Central

    Allan, A. C.; Fricker, M. D.; Ward, J. L.; Beale, M. H.; Trewavas, A. J.

    1994-01-01

    Commelina guard cells can be rapidly closed by abscisic acid (ABA), and it is thought that this signal is always transduced through increases in cytosolic calcium. However, when Commelina plants were grown at 10 to 17[deg]C, most guard cells failed to exhibit any ABA-induced increase in cytosolic calcium even though all of these cells closed. At growth temperatures of 25[deg]C or above, ABA-induced closure was always associated with an increase in cytosolic calcium. This suggests that there may be two transduction routes for ABA in guard cells; only one involves increases in cytosolic calcium. Activation of either pathway on its own appears to be sufficient to cause closure. Because the rates of ABA accumulation and transport in plants grown at different temperatures are likely to be different, we synthesized and microinjected caged ABA directly into guard cells. ABA was released internally by UV photolysis and subsequently caused stomatal closure. This result suggests a possible intracellular locale for the hypothesized ABA receptor. PMID:12244274

  7. [Effects of peeling agents (resorcinol, crystalline sulfur, salicylic acid) on the epidermis of guinea pig (author's transl)].

    PubMed

    Windhager, K; Plewig, G

    1977-08-22

    The mode of action of "classical peeling agents" such as resorcinol, crystalline sulfur, and salicylic acid on the epidermis is almost unknown. There are only a few experimental data available. Therefore the effects of resorcinol, crystalline sulfur, and salicylic acid were studied. A 1% and 3% concentration of these chemicals in vaselinum flavum or Unguentum Cordes was applied to the ears and flanks of adult male guinea pigs up to 14 days. Prior to biopsies at various time intervals, 3H-thymidine was injected intradermally. Specimens were paraffin embedded and routinely processed for autoradiographical analysis. The following parameters were assessed: Labelling index (L.I. in %); number of labelled basal cells per unit length of basement membrane; papillomatosis-index; and acanthosis-factor (projection histoplanimetry). The data were statistically analysed. The peeling agents induced a concentration-dependent increase of the L.I., acanthosis, and papillomatosis. Crystalline sulfur caused the most pronounced effect, followed by resorcinol. In contrast salicylic acid caused only a minute acanthosis factor and a slight increase in labelling. The correlation coefficient r of epidermal thickness to the L.I. for all concentrations and peeling agents used reaches the high figure of 0.978 for the ear. The 1% and 3% salicylic acid has a lower acanthosis factor than vaselinum flavum by itself. Preliminary autoradiographical studies in humans with 1% and 10% salicylic acid confirm these data. Salicylic acid counteracts acanthosis. These experiments show that crystalline sulfur and resorcinol have a potent effect on cell proliferation and acanthosis. They peel via proliferation hyperkeratosis. The mode of peeling by salicylic acid must be different, as cell proliferation and acanthosis are barely enhanced. The clinically known "keratolytic" effect of salicylic acid may be due to a direct action on the intercellular cement substance of the horny cells.

  8. Abscisic acid sensor RCAR7/PYL13, specific regulator of protein phosphatase coreceptors.

    PubMed

    Fuchs, Stefan; Tischer, Stefanie V; Wunschel, Christian; Christmann, Alexander; Grill, Erwin

    2014-04-15

    The plant hormone abscisic acid (ABA) acts both as a developmental signal and as an integrator of environmental cues such as drought and cold. ABA perception recruits an ABA-binding regulatory component [regulatory component of ABA receptor (RCAR)/PYR1/PYL] and an associated protein phosphatase 2C (PP2C). Phytohormone binding inactivates the phosphatase activity of the coreceptor, permitting phosphorelay of the ABA signal via downstream protein kinases. RCARs and PP2C coreceptors are represented by small protein families comprising 14 and 9 members in Arabidopsis, respectively. The specificity of the RCAR-PP2C interaction and the constraints contributing to specific combinations are poorly understood. In this contribution, we analyzed RCAR7/PYL13, which is characterized by three variant amino acid residues in the conserved ABA-binding pocket. RCAR7 regulated the phosphatase activity of the PP2Cs ABI1, ABI2, and PP2CA in vitro at nanomolar ABA levels; however, it was unable to regulate the structurally related hypersensitive to ABA 1 (HAB1). Site-directed mutagenesis of HAB1 established ABA-dependent regulation by RCAR7. Conversion of the noncanonical amino acid residues of RCAR7 into the consensus ABA-binding pocket did not perceptibly change receptor function. Ectopic expression of RCAR7 in Arabidopsis resulted in ABA hypersensitivity affecting gene regulation, seed germination, and stomatal closure. The RCAR7 loss-of-function mutant revealed no changes in ABA responses, similar to the RCAR9 knockout line, whereas the combined deficiency of RCAR7 and RCAR9 resulted in ABA-insensitive seed germination. The study shows a role of RCAR7 in early plant development, proves its ABA receptor function, and identifies structural constraints of RCAR7-PP2C interaction.

  9. Salicylic acid enhances Jaceosidin and Syringin production in cell cultures of Saussurea medusa.

    PubMed

    Yu, Zhen-Zhen; Fu, Chun-Xiang; Han, Ying-Shan; Li, Yong-Xing; Zhao, De-Xiu

    2006-07-01

    Addition of 20 muM salicylic acid to Saussurea medusa cell cultures at day 6 resulted in jaceosidin and syringin productions up to 95 mg l(-1 )and 631 mg l(-1) which were, respectively, about 2.5- and 2.7-fold higher than in the control. The biomass was increased from 8 to 12 g l(-1). Expression of chalcone synthase gene (chs) increased sharply after 12 h treatment and was sustained up to 48 h; chalcone isomerase gene (chi) expression reached a peak at 24 h and decreased after 48 h; and phenylalanine ammonia-lyase activity increased by 7.5-fold (96 U mg(-1) protein) higher than in the control after 24 h. These results indicate that salicylic acid enhances the production of jaceosidin and syringin which is accompanied by induction of the related phenylpropanoid biosynthetic enzymes.

  10. Salicylic Acid Conjugated Dendrimers Are a Tunable, High Performance CEST MRI NanoPlatform.

    PubMed

    Lesniak, Wojciech G; Oskolkov, Nikita; Song, Xiaolei; Lal, Bachchu; Yang, Xing; Pomper, Martin; Laterra, John; Nimmagadda, Sridhar; McMahon, Michael T

    2016-04-13

    Chemical exchange saturation transfer (CEST) is a novel MRI contrast mechanism that is well suited for imaging, however, existing small molecule CEST agents suffer from low sensitivity. We have developed salicylic acid conjugated dendrimers as a versatile, high performance nanoplatform. In particular, we have prepared nanocarriers based on generation 5-poly(amidoamine) (PAMAM) dendrimers with salicylic acid covalently attached to their surface. The resulting conjugates produce strong CEST contrast 9.4 ppm from water with the proton exchange tunable from ∼1000 s(-1) to ∼4500 s(-1) making these dendrimers well suited for sensitive detection. Furthermore, we demonstrate that these conjugates can be used for monitoring convection enhanced delivery into U87 glioblastoma bearing mice, with the contrast produced by these nanoparticles persisting for over 1.5 h and distributed over ∼50% of the tumors. Our results demonstrate that SA modified dendrimers present a promising new nanoplatform for medical applications.

  11. Salicylic Acid-Based Organic Dyes Acting as the Photosensitizer for Solar Cells.

    PubMed

    Hong, Sungjun; Park, Jae-Hyeong; Han, Ah-Reum; Ko, Kwan-Woo; Eom, Jin Hee; Namgoong, Sung Keon; Lo, Alvie S V; Gordon, Keith C; Yoon, Sungho; Han, Chi-Hwan

    2016-05-01

    A D-π-A metal-free organic dye, featuring salicylic acid as a novel acceptor/anchoring unit, has been designed, synthesized and applied to dye-sensitized solar cell. The detailed photophysical, electrochemical, photovoltaic and sensitizing properties of the organic dye were investigated, in addition to the computational studies of the dye and dye-(TiO2)6 system. A solar cell device using this new organic dye as a sensitizer produced a solar to electric power conversion efficiency (PCE) of 3.49% (J(sc) = 6.69 mAcm-2, V(oc) = 0.74 V and ff = 0.70) under 100 mWcm(-2) simulated AM 1.5 G solar irradiation, demonstrating that the salicylic acid-based organic dye is a suitable alternative to currently used organometallic dyes.

  12. Passive permeability of salicylic acid in renal proximal S2 and S3 tubules

    SciTech Connect

    Chatton, J.Y.; Roch-Ramel, F. )

    1991-03-01

    The role of nonionic diffusion in the transport of salicylic acid across rabbit proximal S2 and S3 segments was investigated using the in vitro isolated perfused tubule technique. The ({sup 14}C) salicylic acid apparent reabsorptive permeability (P'I-b, 10(-5) cm/s) was measured at 19 degrees C with luminal solutions kept at different pH and bath maintained at pH 7.4. In S2 tubules, P'I-b was 25.0 +/- 3.5 when luminal pH was 6.0; P'I-b decreased to 8.1 +/- 1.4 and to 4.4 +/- 1.2 at a luminal pH of 6.5 and 7.0, respectively. In S3 tubules, P'I-b was 17.6 +/- 2.4, 5.3 +/- 1.1 and 3.4 +/- 1.1 at a luminal pH of 6.0, 6.5 and 7.0, respectively. There was a close correlation between P'I-b and the calculated proportion of nonionized salicylic acid present at each pH, indicating that only the nonionized molecule could diffuse in our conditions. We calculated the apparent permeability of nonionic salicylic acid and found 0.248 +/- 0.032 cm/s for S2 and 0.176 +/- 0.022 cm/s for S3 tubules. These calculated permeabilities were independent of pH.

  13. ESR study of irradiated single crystals of the cocrystalline complex of cytidine: Salicylic acid

    SciTech Connect

    Close, D.M.; Sagstuen, E.

    1983-12-01

    Irradiation at 77 K of single crystals of the 1:1 complex of cytidine and salicylic acid produces a phenoxyl radical formed by oxidation of the salicylic acid. Anisotropic hyperfine coupling tensors have been determined for this radical which are associated with the para and ortho hydrogens. No cytidine oxidation products (alkoxy or hydroxyalkyl radicals) were observed at 77 K. Following the decay of the phenoxyl radical at room temperature, four radicals were detected. These include the cytosine 5--yl and 6--yl radicals, formed by H addition to the cytosine ring, and an anisotropic doublet. By UV irradiation at room temperature, it is possible to convert a significant fraction of 6-yl radicals into 5-yl radicals. Hyperfine coupling and g tensors determined for the anisotropic doublet indicate that this radical is formed in the C/sub 1'/-C/sub 2'/ region of the sugar moiety. These results indicate a shift in radiation damage away from the salicylic acid upon warming, and show that the radiation chemistry of the cocrystalline complex is different from that of the isolated bases.

  14. Hydrothermal synthesis spherical TiO2 and its photo-degradation property on salicylic acid

    NASA Astrophysics Data System (ADS)

    Guo, Wenlu; Liu, Xiaolin; Huo, Pengwei; Gao, Xun; Wu, Di; Lu, Ziyang; Yan, Yongsheng

    2012-07-01

    Anatase TiO2 spheres have been prepared using hydrothermal synthesis. The prepared spheres were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and UV-vis diffuse reflectance spectra (UV-vis DRS). The TiO2 consisted of well-defined spheres with size of 3-5 μm. The photocatalytic activity of spherical TiO2 was determined by degradation of salicylic acid under visible light irradiation. It was revealed that the degradation rate of the spherical TiO2 which was processed at 150 °C for 48 h could reach 81.758%. And the kinetics of photocatalytic degradation obeyed first-order kinetic, which the rate constant value was 0.01716 S-1 of the salicylic acid onto TiO2 (temperature: 150, time: 48 h). The kinetics of adsorption followed the pseudo-second-order model and the rate constant was 1.2695 g mg-1 of the salicylic acid onto TiO2 (temperature: 150, time: 48 h).

  15. DFT computational study on decarboxylation mechanism of salicylic acid and its derivatives in the anionic state

    NASA Astrophysics Data System (ADS)

    Gao, Lu; Hu, Yanying; Zhang, Huitu; Liu, Yanchun; Song, Zhidan; Dai, Yujie

    2016-07-01

    The mechanisms of the decarboxylation of salicylic acid anion and its ortho substituted derivatives in gas phase and aqueous solution have been investigated by B3LYP method of DFT theory using the 6-31++G (d,p) basis set. The decarboxylation process includes hydrogen transfers from hydroxyl to carboxyl group and from carboxyl to the α-C of the aryl ring. The mechanism suggested is a pseudo-unimolecular decomposition of the salicylic acid anion and the hydrogen transfer from carboxyl to the α-C of the aryl ring is the rate determining step. Compared with the decarboxylation process in gas phase, the energy barriers in aqueous solution approximately declined by 25%-31%with the water mediation of the hydrogen transfer from carboxyl to the α-C of the aryl ring. The effects of substituents at the ortho position on the decarboxylation process were also investigated. Both the electron donating CH3 and withdrawing group NO2 at the ortho position of carboxyl group can further reduce the reaction energy barriers of the decarboxylation of salicylic acid anions.

  16. Effect of salicylic acid on morphological and biochemical attributes in cowpea.

    PubMed

    Chandra, A; Anand, A; Dubey, A

    2007-04-01

    Effects of salicylic acid (SA) on seed germination, seedling growth, flowering and biochemical activities were studied out in four cowpea (Vigna unguiculata) genotypes in control environments. The results revealed that both germination and seedling growth were negatively affected by 0.02%. SA application, however did not affect the size of full expanded buds, time of 50% flowering and date of flower initiation. A maximum increase in peroxidase (EC1.11.1.7) activity was observed in UPC 4200 over other genotypes. No significant change in the content of total soluble and intercellular fluid proteins was observed except in UPC 4200 genotype. SA induced accumulation of total soluble sugars more at flowering stage than at seed setting stage. It is evident from the present study that UPC 4200 genotype was more responsive to salicylic acid both in terms of increased peroxidase activity and less negative effect on morphological attributes, thus suggesting its wider use without negative impact on environment as salicylic acid has been reported in plants.

  17. Altered cultivar resistance of kimchi cabbage seedlings mediated by salicylic Acid, jasmonic Acid and ethylene.

    PubMed

    Lee, Young Hee; Kim, Sang Hee; Yun, Byung-Wook; Hong, Jeum Kyu

    2014-09-01

    Two cultivars Buram-3-ho (susceptible) and CR-Hagwang (moderate resistant) of kimchi cabbage seedlings showed differential defense responses to anthracnose (Colletotrichum higginsianum), black spot (Alternaria brassicicola) and black rot (Xanthomonas campestris pv. campestris, Xcc) diseases in our previous study. Defense-related hormones salicylic acid (SA), jasmonic acid (JA) and ethylene led to different transcriptional regulation of pathogenesis-related (PR) gene expression in both cultivars. In this study, exogenous application of SA suppressed basal defenses to C. higginsianum in the 1st leaves of the susceptible cultivar and cultivar resistance of the 2nd leaves of the resistant cultivar. SA also enhanced susceptibility of the susceptible cultivar to A. brassicicola. By contrast, SA elevated disease resistance to Xcc in the resistant cultivar, but not in the susceptible cultivar. Methyl jasmonate (MJ) treatment did not affect the disease resistance to C. higginsianum and Xcc in either cultivar, but it compromised the disease resistance to A. brassicicola in the resistant cultivar. Treatment with 1-aminocyclopropane-1-carboxylic acid (ACC) ethylene precursor did not change resistance of the either cultivar to C. higginsianum and Xcc. Effect of ACC pretreatment on the resistance to A. brassicicola was not distinguished between susceptible and resistant cultivars, because cultivar resistance of the resistant cultivar was lost by prolonged moist dark conditions. Taken together, exogenously applied SA, JA and ethylene altered defense signaling crosstalk to three diseases of anthracnose, black spot and black rot in a cultivar-dependent manner.

  18. Salicylic acid and ascorbic acid retrieve activity of antioxidative enzymes and structure of Caralluma tuberculata calli on PEG stress.

    PubMed

    Rehman, Riaz U; Zia, Muhammad; Chaudhary, Muhammad F

    2017-02-02

    Biochemical adaptations and morphological changes are cellular aptitude originated on biotic and abiotic stresses. Polyethylene glycol (PEG) induces drought stress in the nutrient solution. In the present investigation, Caralluma tuberculata calli is exposed to PEG and antioxidative molecules. By increasing the level of antioxidative enzymes (SOD, POD, CAT, APX, and GR), the PEG-stressed calli falls off upon exposure to non-enzymatic antioxidants (ascorbic acid and salicylic acid). Under PEG-stress, several cellular and sub-cellular changes such as alteration in plasma membrane thickness, change in nucleus shape, increase in nucleoli, deformation of thylakoid membranes, and increase in plastoglobuli are observed through electron microscopic images. From our results we conclude that application of PEG (a drought causative agent) leads to an increase in the level of antioxidative enzymes and also deformation of cellular organelles. However, application of ascorbic acid and salicylic acid eradicate drought effect induced by PEG.

  19. Photoprotectant improves photostability and bioactivity of abscisic acid under UV radiation.

    PubMed

    Gao, Fei; Hu, Tanglu; Tan, Weiming; Yu, Chunxin; Li, Zhaohu; Zhang, Lizhen; Duan, Liusheng

    2016-05-01

    Photosensitivity causes serious drawback for abscisic acid (ABA) application, but preferable methods to stabilize the compound were not found yet. To select an efficient photoprotectant for the improvement of photostability and bioactivity of ABA when exposed to UV light, we tested the effects of a photostabilizer bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (HS-770) and two UV absorbers 2-hydroxy-4-n-octoxy-benzophenone (UV-531) and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (BP-4) with or without HS-770 on the photodegradation of ABA. Water soluble UV absorber BP-4 and oil soluble UV absorber UV-531 showed significant photo-stabilizing capability on ABA, possibly due to competitive energy absorption of UVB by the UV absorbers. The two absorbers showed no significant difference. Photostabilizer HS-770 accelerated the photodegradation of ABA and did not improve the photo-stabilizing capability of BP-4, likely due to no absorption in UVB region and salt formation with ABA and BP-4. Approximately 26% more ABA was kept when 280mg/l ABA aqueous solution was irradiated by UV light for 2h in the presence of 200mg/l BP-4. What's more, its left bioactivity on wheat seed (JIMAI 22) germination was greatly kept by BP-4, comparing to that of ABA alone. The 300 times diluent of 280mg/l ABA plus 200mg/l BP-4 after 2h irradiation showed more than 13% inhibition on shoot and root growth of wheat seed than that of ABA diluent alone. We concluded that water soluble UV absorber BP-4 was an efficient agent to keep ABA activity under UV radiation. The results could be used to produce photostable products of ABA compound or other water soluble agrichemicals which are sensitive to UV radiation. The frequencies and amounts of the agrichemicals application could be thereafter reduced.

  20. The role of abscisic acid in regulating cucumber fruit development and ripening and its transcriptional regulation.

    PubMed

    Wang, Yanping; Wang, Ya; Ji, Kai; Dai, Shengjie; Hu, Ying; Sun, Liang; Li, Qian; Chen, Pei; Sun, Yufei; Duan, Chaorui; Wu, Yan; Luo, Hao; Zhang, Dian; Guo, Yangdong; Leng, Ping

    2013-03-01

    Cucumber (Cucumis sativus L.), a kind of fruit usually harvested at the immature green stage, belongs to non-climacteric fruit. To investigate the contribution of abscisic acid (ABA) to cucumber fruit development and ripening, variation in ABA level was investigated and a peak in ABA level was found in pulp before fruit get fully ripe. To clarify this point further, exogenous ABA was applied to cucumber fruits at two different development stages. Results showed that ABA application at the turning stage promotes cucumber fruit ripening, while application at the immature green stage had inconspicuous effects. In addition, with the purpose of understanding the transcriptional regulation of ABA, two partial cDNAs of CsNCED1 and CsNCED2 encoding 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthetic pathway; one partial cDNA of CsCYP707A1 for 8'-hydroxylase, a key enzyme in the oxidative catabolism of ABA and two partial cDNAs of CsBG1 and CsBG2 for β-glucosidase (BG) that hydrolyzes ABA glucose ester (ABA-GE) to release active ABA were cloned from cucumber. The DNA and deduced amino acid sequences of these obtained genes respectively showed high similarities to their homologous genes in other plants. Real-time PCR analysis revealed that ABA content may be regulated by its biosynthesis (CsNCEDs), catabolism (CsCYP707A1) and reactivation genes (CsBGs) at the transcriptional level during cucumber fruit development and ripening, in response to ABA application, dehydration and pollination, among which CsNCED1, CsCYP707A1 and CsBG1 were highly expressed in pulp and may play more important roles in regulating ABA metabolism.

  1. Sensitivity of Stomata to Abscisic Acid (An Effect of the Mesophyll).

    PubMed Central

    Trejo, C. L.; Davies, W. J.; Ruiz, LdMP.

    1993-01-01

    The effects of added abscisic acid (ABA) on the stomatal behavior of Commelina communis L. were tested using three different systems. ABA was applied to isolated epidermis or to leaf pieces incubated in the light in bathing solutions perfused with CO2-free air. ABA was also fed to detached leaves in a transpiration bioassay. The apparent sensitivity of stomata to ABA was highly dependent on the method used to feed ABA. Stomata of isolated epidermis were apparently most sensitive to ABA, such that a concentration of 1 [mu]M caused almost complete stomatal closure. When pieces of whole leaves were floated on solutions of ABA of the same concentration, the stomata were almost completely open. The same concentration of ABA fed through the midrib of transpiring detached leaves caused an intermediate response. These differences in stomatal sensitivity to added ABA were found to be a function of differences in the ABA concentration in the epidermes. Comparison of the three application systems suggested that, when leaf pieces were incubated in ABA or fed with ABA through the midrib, accumulation of ABA in the epidermes was limited by the presence of the mesophyll. Even bare mesophyll incubated in ABA solution did not accumulate ABA. Accumulation of radioactivity by leaf pieces floated on [3H]ABA confirmed ABA uptake in this system. Experiments with tetcyclacis, an inhibitor of phaseic acid formation, suggested that rapid metabolism of ABA in mesophyll can have a controlling influence on ABA concentration in both the mesophyll and the epidermis. Inhibition of ABA catabolism with tetcyclacis allows ABA accumulation and increases the apparent sensitivity of stomata to applied ABA. The results are discussed in the context of an important role for ABA metabolism in the regulation of stomatal behavior. PMID:12231838

  2. Effects of abscisic acid and xanthoxin on elongation and gravitropism in primary roots of Zea mays

    NASA Technical Reports Server (NTRS)

    Lee, J. S.; Hasenstein, K. H.; Mulkey, T. J.; Yang, R. L.; Evans, M. L.

    1990-01-01

    We examined the involvement of abscisic acid (ABA) and xanthoxin (Xan) in maize root gravitropism by (1) testing the ability of ABA to allow positive gravitropism in dark-grown seedlings of the maize cultivar LG11, a cultivar known to require light for positive gravitropism of the primary root, (2) comparing curvature in roots in which half of the cap had been excised and replaced with agar containing either ABA or indole-3-acetic acid (IAA), (3) measuring gravitropism in roots of seedlings submerged in oxygenated solutions of ABA or IAA and (4) testing the effect of Xan on root elongation. Using a variety of methods of applying ABA to the root, we found that ABA did not cause horizontally-oriented primary roots of dark-grown seedlings to become positively gravitropic. Replacing half of the root cap of vertically oriented roots with an agar block containing ABA had little or no effect on curvature relative to that of controls in which the half cap was replaced by a plain agar block. Replacement of the removed half cap with IAA either canceled or reversed the curvature displayed by controls. When light-grown seedlings were submerged in ABA they responded strongly to gravistimulation while those in IAA did not. Xan (up to 0.1 mM) did not affect root elongation. The results indicate that ABA is not a likely mediator of root gravitropism and that the putative ABA precursor, Xan, lacks the appropriate growth-inhibiting properties to serve as a mediator of root gravitropism.

  3. Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress.

    PubMed

    Zhou, Lin; Xu, Hui; Mischke, Sue; Meinhardt, Lyndel W; Zhang, Dapeng; Zhu, Xujun; Li, Xinghui; Fang, Wanping

    2014-01-01

    Tea [Camellia sinensis (L.) O. Kuntze] is an important economic crop, and drought is the most important abiotic stress affecting yield and quality. Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance. Increased understanding of ABA effects on tea plant under drought stress is essential to develop drought-tolerant tea genotypes, along with crop management practices that can mitigate drought stress. The objective of the present investigation is evaluation of effects of exogenous ABA on the leaf proteome in tea plant exposed to drought stress. Leaf protein patterns of tea plants under simulated drought stress [(polyethylene glycol (PEG)-treated] and exogenous ABA treatment were analyzed in a time-course experiment using two-dimensional electrophoresis (2-DE), followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Among the 72 protein spots identified by MALDI-TOF MS, 16 proteins were downregulated and two were upregulated by exogenous ABA. The upregulated proteins have roles in glycolysis and photosystem II stabilization. Twenty-one protein spots were responsive to drought stress and most participate in carbohydrate and nitrogen metabolism, control of reactive oxygen species (ROS), defense, signaling or nucleic acid metabolism. The combined treatments of exogenous ABA and drought showed upregulation of 10 protein spots at 12 h and upregulation of 11 proteins at 72 h after initiation of drought stress. The results support the importance of the role that ABA plays in the tea plant during drought stress, by improving protein transport, carbon metabolism and expression of resistance proteins.

  4. Histidine Regulates Seed Oil Deposition through Abscisic Acid Biosynthesis and β-Oxidation.

    PubMed

    Ma, Huimin; Wang, Shui

    2016-10-01

    The storage compounds are deposited into plant seeds during maturation. As the model oilseed species, Arabidopsis (Arabidopsis thaliana) has long been studied for seed oil deposition. However, the regulation of this process remains unclear. Through genetic screen with a seed oil body-specific reporter, we isolated low oil1 (loo1) mutant. LOO1 was mapped to HISTIDINE BIOSYNTHESIS NUMBER 1A (HISN1A). HISN1A catalyzes the first step of His biosynthesis. Oil significantly decreased, and conversely proteins markedly increased in hisn1a mutants, indicating that HISN1A regulates both oil accumulation and the oil-protein balance. HISN1A was predominantly expressed in embryos and root tips. Accordingly, the hisn1a mutants exhibited developmental phenotype especially of seeds and roots. Transcriptional profiling displayed that β-oxidation was the major metabolic pathway downstream of HISN1A β-Oxidation was induced in hisn1a mutants, whereas it was reduced in 35S:HISN1A-transgenic plants. In plants, seed storage oil is broken-down by β-oxidation, which is controlled by abscisic acid (ABA). We found that His activated genes of ABA biosynthesis and correspondingly advanced ABA accumulation. Exogenous ABA rescued the defects of hisn1a mutants, whereas mutation of ABA DEFICIENT2, a key enzyme in ABA biosynthesis, blocked the effect of His on β-oxidation, indicating that ABA mediates His regulation in β-oxidation. Intriguingly, structural analysis showed that a potential His-binding domain was present in the general amino acid sensors GENERAL CONTROL NON-DEREPRESSIBLE2 and PII, suggesting that His may serve as a signal molecule. Taken together, our study reveals that His promotes plant seed oil deposition through ABA biosynthesis and β-oxidation.

  5. Transport of two naphthoic acids and salicylic acid in soil: experimental study and empirical modeling.

    PubMed

    Hanna, K; Lassabatere, L; Bechet, B

    2012-09-15

    In contrast to the parent compounds, the mechanisms responsible for the transport of natural metabolites of polycyclic aromatic hydrocarbons (PAH) in contaminated soils have been scarcely investigated. In this study, the sorption of three aromatic acids (1-naphthoic acid (NA), 1-hydroxy-2-naphthoic acid (HNA) and salicylic acid (SA)) was examined on soil, in a batch equilibrium single-system, with varying pH and acid concentrations. Continuous flow experiments were also carried out under steady-state water flow. The adsorption behavior of naphthoic and benzoic acids was affected by ligand functionality and molecular structure. All modeling options (equilibrium, chemical nonequilibrium, i.e. chemical kinetics, physical nonequilibrium, i.e. surface sites in the immobile water fraction, and both chemical and physical nonequilibrium) were tested in order to describe the breakthrough behavior of organic compounds in homogeneously packed soil columns. Tracer experiments showed a small fractionation of flow into mobile and immobile compartments, and the related hydrodynamic parameters were used for the modeling of reactive transport. In all cases, the isotherm parameters obtained from column tests differed from those derived from the batch experiments. The best accurate modeling was obtained considering nonequilibrium for the three organic compounds. Both chemical and physical nonequilibrium led to appropriate modeling for HNA and NA, while chemical nonequilibrium was the sole option for SA. SA sorption occurs mainly in mobile water and results from the concomitancy of instantaneous and kinetically limited sites. For all organic compounds, retention is contact condition dependent and differs between batch and column experiments. Such results show that preponderant mechanisms are solute dependent and kinetically limited, which has important implications for the fate and transport of carboxylated aromatic compounds in contaminated soils.

  6. Fermentation products of solvent tolerant marine bacterium Moraxella spp. MB1 and its biotechnological applications in salicylic acid bioconversion.

    PubMed

    Wahidullah, Solimabi; Naik, Deepak N; Devi, Prabha

    2013-01-01

    As part of a proactive approach to environmental protection, emerging issues with potential impact on the environment is the subject of ongoing investigation. One emerging area of environmental research concerns pharmaceuticals like salicylic acid, which is the main metabolite of various analgesics including aspirin. It is a common component of sewage effluent and also an intermediate in the degradation pathway of various aromatic compounds which are introduced in the marine environment as pollutants. In this study, biotransformation products of salicylic acid by seaweed, Bryopsis plumosa, associated marine bacterium, Moraxella spp. MB1, have been investigated. Phenol, conjugates of phenol and hydroxy cinnamic acid derivatives (coumaroyl, caffeoyl, feruloyl and trihydroxy cinnamyl) with salicylic acid (3-8) were identified as the bioconversion products by electrospray ionization mass spectrometry. These results show that the microorganism do not degrade phenolic acid but catalyses oxygen dependent transformations without ring cleavage. The degradation of salicylic acid is known to proceed either via gentisic acid pathway or catechol pathway but this is the first report of biotransformation of salicylic acid into cinnamates, without ring cleavage. Besides cinnamic acid derivatives (9-12), metabolites produced by the bacterium include antimicrobial indole (13) and β-carbolines, norharman (14), harman (15) and methyl derivative (16), which are beneficial to the host and the environment.

  7. Lipid metabolism is differentially modulated by salicylic acid and heptanoyl salicylic acid during the induction of resistance in wheat against powdery mildew.

    PubMed

    Tayeh, Christine; Randoux, Béatrice; Bourdon, Natacha; Reignault, Philippe

    2013-12-15

    Heptanoyl salicylic acid (HSA) is a salicylic acid (SA) derivative obtained by esterification of 2-OH benzoic acid with heptanoic acid. In wheat, the protection levels obtained against Blumeria graminis f. sp. tritici (Bgt) increased from 50% with SA to 95% with HSA. Using molecular, biochemical and cytological approaches, we investigated here how wheat lipid metabolism is differentially activated by SA and HSA in both infectious and non-infectious conditions, and how Bgt infectious process is altered by both inducers. First, in the absence of Bgt, continuous lipoxygenase (LOX)-encoding gene expression and corresponding activity were specifically induced by HSA. Moreover, compared to SA, HSA treatment resulted in earlier up-regulations of the phospholipase C2-encoding gene expression and it specifically affected the expression of a lipid transfer protein-encoding gene. In infectious context, both HSA and SA sprayings impaired penetration events and therefore haustorium formation, leading to less frequent fungal colonies. While this alteration only slowed down the evolution of Bgt infectious process in SA-sprayed leaves, it completely impaired the establishment of successful infectious events in HSA-sprayed leaves. In addition, HSA induced continuous increases of a LOX-encoding gene expression and of the corresponding LOX activity when compared to SA-sprayed leaves. Lipid metabolism is therefore overall highly responsive to HSA spraying and could represent effective defence mechanism triggered during the induction of resistance in wheat toward Bgt. The concepts of priming and energy costs of the defences induced by SA and HSA are also discussed.

  8. Binding of diazepam, salicylic acid and digitoxin to albumin isolated from fetal and adult serum.

    PubMed

    Viani, A; Cappiello, M; Pacifici, G M

    1991-01-01

    Albumin was isolated from pooled fetal serum obtained at normal delivery at term and from pooled adult plasma. Albumin isolation was carried out by means of PEG precipitation followed by ion exchange chromatography on DEAE-Sephadex A 50 and then on SP-Sephadex C 50. The binding of diazepam (1 microM), salicylic acid (2 mM) and digitoxin (6 nM) to albumin (40 g/l) was measured by equilibrium dialysis at 37 degrees C. The unbound fraction (mean +/- SD) for fetal and adult albumin of diazepam was 1.86 +/- 0.24 and 1.82 +/- 0.15% (NS), that of digitoxin was 3.18 +/- 0.27 and 3.36 +/- 0.04% (NS) and that of salicylic acid was 11.65 +/- 0.99 and 9.47 +/- 0.75% (p less than 0.05), respectively. With both fetal and adult albumin, a single class of binding sites was observed for diazepam and digitoxin, whereas two classes of binding sites were observed for salicylic acid. The number of binding sites (n, moles of drug per mole of albumin) for fetal and adult albumin was 0.83 and 1.02 for diazepam and 0.014 and 0.018 for digitoxin, respectively. For salicylic acid, n was 1.45 (fetal albumin) and 1.55 (adult albumin) for the higher affinity site, and 3.06 (fetal albumin) and 3.27 (adult albumin) for the lower affinity site. The association constant (Ka, M-1) for diazepam was 1.36 x 10(5) (fetal albumin) and 1.00 x 10(5) (adult albumin) and that for digitoxin was 4.12 x 10(6) (fetal albumin) and 2.7 x 10(6) (adult albumin). For salicylic acid, Ka was 38.4 x 10(3) (fetal albumin) and 35.8 x 10(3) (adult albumin) for the higher affinity site, and 2.7 x 10(3) (fetal albumin) and 4.3 x 10(3) (adult albumin) for the lower affinity site. This work shows that fetal and adult albumin have similar binding properties and corroborates our previous findings with furosemide.

  9. Salicylic acid promotes seed germination under high salinity by modulating antioxidant activity in Arabidopsis.

    PubMed

    Lee, Sangmin; Kim, Sang-Gyu; Park, Chung-Mo

    2010-10-01

    • Findings regarding the role of salicylic acid (SA) in seed germination are somewhat variable, depending on the plant genotypes and experimental conditions used, and thus the molecular mechanisms underlying SA regulation of germination are still unclear. Here, we report that physiological concentrations of SA promote germination under high salinity by modulating antioxidant activity in Arabidopsis. • Germination of SA induction deficient 2 (sid2) seeds was hypersensitive to high salinity. While the inhibitory effect of high salinity was exaggerated in the presence of higher concentrations of SA (> 100 μM), it was significantly reduced in the presence of lower concentrations of SA (< 50 μM). Under high salinity, the endogenous contents of H(2) O(2) were elevated in wild-type and sid2 seeds but reduced to original concentrations after treatment with 1 μM SA. • Germination of NahG transgenic plants was influenced to a lesser degree by high salinity (NahG is a bacterial gene encoding salicylate hydroxylase that converts salicylic acid to catechol). We found that catechol, an SA degradation product accumulated in the transgenic plants, acts as an antioxidant that compromises the inhibitory effects of high salinity. • Our observations indicate that, although SA is not essential for germination under normal growth conditions, it plays a promotive role in seed germination under high salinity by reducing oxidative damage.

  10. Integrating nitric oxide into salicylic acid and jasmonic acid/ ethylene plant defense pathways.

    PubMed

    Mur, Luis A J; Prats, Elena; Pierre, Sandra; Hall, Michael A; Hebelstrup, Kim H

    2013-01-01

    Plant defense against pests and pathogens is known to be conferred by either salicylic acid (SA) or jasmonic acid (JA)/ethylene (ET) pathways, depending on infection or herbivore-grazing strategy. It is well attested that SA and JA/ET pathways are mutually antagonistic allowing defense responses to be tailored to particular biotic stresses. Nitric oxide (NO) has emerged as a major signal influencing resistance mediated by both signaling pathways but no attempt has been made to integrate NO into established SA/JA/ET interactions. NO has been shown to act as an inducer or suppressor of signaling along each pathway. NO will initiate SA biosynthesis and nitrosylate key cysteines on TGA-class transcription factors to aid in the initiation of SA-dependent gene expression. Against this, S-nitrosylation of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1) will promote the NPR1 oligomerization within the cytoplasm to reduce TGA activation. In JA biosynthesis, NO will initiate the expression of JA biosynthetic enzymes, presumably to over-come any antagonistic effects of SA on JA-mediated transcription. NO will also initiate the expression of ET biosynthetic genes but a suppressive role is also observed in the S-nitrosylation and inhibition of S-adenosylmethionine transferases which provides methyl groups for ET production. Based on these data a model for NO action is proposed but we have also highlighted the need to understand when and how inductive and suppressive steps are used.

  11. Integrating nitric oxide into salicylic acid and jasmonic acid/ ethylene plant defense pathways

    PubMed Central

    Mur, Luis A. J.; Prats, Elena; Pierre, Sandra; Hall, Michael A.; Hebelstrup, Kim H.

    2013-01-01

    Plant defense against pests and pathogens is known to be conferred by either salicylic acid (SA) or jasmonic acid (JA)/ethylene (ET) pathways, depending on infection or herbivore-grazing strategy. It is well attested that SA and JA/ET pathways are mutually antagonistic allowing defense responses to be tailored to particular biotic stresses. Nitric oxide (NO) has emerged as a major signal influencing resistance mediated by both signaling pathways but no attempt has been made to integrate NO into established SA/JA/ET interactions. NO has been shown to act as an inducer or suppressor of signaling along each pathway. NO will initiate SA biosynthesis and nitrosylate key cysteines on TGA-class transcription factors to aid in the initiation of SA-dependent gene expression. Against this, S-nitrosylation of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1) will promote the NPR1 oligomerization within the cytoplasm to reduce TGA activation. In JA biosynthesis, NO will initiate the expression of JA biosynthetic enzymes, presumably to over-come any antagonistic effects of SA on JA-mediated transcription. NO will also initiate the expression of ET biosynthetic genes but a suppressive role is also observed in the S-nitrosylation and inhibition of S-adenosylmethionine transferases which provides methyl groups for ET production. Based on these data a model for NO action is proposed but we have also highlighted the need to understand when and how inductive and suppressive steps are used. PMID:23818890

  12. Modulation of human stratum corneum properties by salicylic acid and all-trans-retinoic acid.

    PubMed

    Piérard-Franchimont, C; Goffin, V; Piérard, G E

    1998-01-01

    Topical all-trans-retinoic acid (RA) has been reported to decrease the in vivo skin response to sodium lauryl sulfate (SLS). The converse was also shown with a synergistic effect of RA following prior applications of SLS. The reason for such effects is not clear. We employed measures of transepidermal water loss (TEWL), squamometry and sequential corneosurfametry to explore the protective activity of a 0.05% RA cream at the level of the stratum corneum. Nonionic oil-in-water emulsions with or without 5% salicylic acid (SA) served as test product references. Data indicated that the RA formulation was responsible for a stochastic impairment in the TEWL and for an increased intercorneocyte cohesion. SA and the unmedicated emulsion did not lead to similar TEWL changes. The squamometry test proved to be very sensitive to disclose the effects of SA and RA without, however, allowing to distinguish the difference in the physiological processes involved. The corneosurfametry bioassay did not show any protection or synergistic effect between RA or SA and SLS challenge on the stratum corneum. This is in contrast to a previous work showing a positive protective effect afforded by retinol against SLS. The combined effects of irritant compounds affecting the stratum corneum are complex. The precise reason for some of their biological consequences remains a conundrum. On balance, products such as SA and RA do not appear to afford protection or impairment to a surfactant challenge at the level of the stratum corneum.

  13. AtWRKY22 promotes susceptibility to aphids and modulates salicylic acid and jasmonic acid signalling

    PubMed Central

    Kloth, Karen J.; Wiegers, Gerrie L.; Busscher-Lange, Jacqueline; van Haarst, Jan C.; Kruijer, Willem; Bouwmeester, Harro J.; Dicke, Marcel; Jongsma, Maarten A.

    2016-01-01

    Aphids induce many transcriptional perturbations in their host plants, but the signalling cascades responsible and the effects on plant resistance are largely unknown. Through a genome-wide association (GWA) mapping study in Arabidopsis thaliana, we identified WRKY22 as a candidate gene associated with feeding behaviour of the green peach aphid, Myzus persicae. The transcription factor WRKY22 is known to be involved in pathogen-triggered immunity, and WRKY22 gene expression has been shown to be induced by aphids. Assessment of aphid population development and feeding behaviour on knockout mutants and overexpression lines showed that WRKY22 increases susceptibility to M. persicae via a mesophyll-located mechanism. mRNA sequencing analysis of aphid-infested wrky22 knockout plants revealed the up-regulation of genes involved in salicylic acid (SA) signalling and down-regulation of genes involved in plant growth and cell-wall loosening. In addition, mechanostimulation of knockout plants by clip cages up-regulated jasmonic acid (JA)-responsive genes, resulting in substantial negative JA–SA crosstalk. Based on this and previous studies, WRKY22 is considered to modulate the interplay between the SA and JA pathways in response to a wide range of biotic and abiotic stimuli. Its induction by aphids and its role in suppressing SA and JA signalling make WRKY22 a potential target for aphids to manipulate host plant defences. PMID:27107291

  14. 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.

  15. 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

  16. 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.

  17. The Pepper CaOSR1 Protein Regulates the Osmotic Stress Response via Abscisic Acid Signaling

    PubMed Central

    Park, Chanmi; Lim, Chae Woo; Lee, Sung Chul

    2016-01-01

    Plants are sessile organisms, and their growth and development is detrimentally affected by environmental stresses such as drought and high salinity. Defense mechanisms are tightly regulated and complex processes, which respond to changing environmental conditions; however, the precise mechanisms that function under adverse conditions remain unclear. Here, we report the identification and functional characterization of the CaOSR1 gene, which functions in the adaptive response to abiotic stress. We found that CaOSR1 gene expression in pepper leaves was up-regulated after exposure to abscisic acid (ABA), drought, and high salinity. In addition, we demonstrated that the fusion protein of CaOSR1 with green fluorescent protein (GFP) is localized in the nucleus. We used CaOSR1-silenced pepper plants and CaOSR1-OX-overexpressing (OX) transgenic Arabidopsis plants to show that the CaOSR1 protein regulates the osmotic stress response. CaOSR1-silenced pepper plants showed increased drought susceptibility, and this was accompanied by a high transpiration rate. CaOSR1-OX plants displayed phenotypes that were hypersensitive to ABA and hyposensitive to osmotic stress, during the seed germination and seedling growth stages; furthermore, these plants exhibited enhanced drought tolerance at the adult stage, and this was characterized by higher leaf temperatures and smaller stomatal apertures because of ABA hypersensitivity. Taken together, our data indicate that CaOSR1 positively regulates osmotic stress tolerance via ABA-mediated cell signaling. These findings suggest an involvement of a novel protein in ABA and osmotic stress signalings in plants. PMID:27446121

  18. Abscisic acid and 14-3-3 proteins control K channel activity in barley embryonic root.

    PubMed

    van den Wijngaard, Paul W J; Sinnige, Mark P; Roobeek, Ilja; Reumer, Annet; Schoonheim, Peter J; Mol, Jos N M; Wang, Mei; De Boer, Albertus H

    2005-01-01

    Germination of seeds proceeds in general in two phases, an initial imbibition phase and a subsequent growth phase. In grasses like barley, the latter phase is evident as the emergence of the embryonic root (radicle). The hormone abscisic acid (ABA) inhibits germination because it prevents the embryo from entering and completing the growth phase. Genetic and physiological studies have identified many steps in the ABA signal transduction cascade, but how it prevents radicle elongation is still not clear. For elongation growth to proceed, uptake of osmotically active substances (mainly K(+)) is essential. Therefore, we have addressed the question of how the activity of K(+) permeable ion channels in the plasma membrane of radicle cells is regulated under conditions of slow (+ABA) and rapid germination (+fusicoccin). We found that ABA arrests radicle growth, inhibits net K(+) uptake and reduces the activity of K(+) (in) channels as measured with the patch-clamp technique. In contrast, fusicoccin (FC), a well-known stimulator of germination, stimulates radicle growth, net K(+) uptake and reduces the activity of K(+) (out) channels. Both types of channels are under the control of 14-3-3 proteins, known as integral components of signal transduction pathways and instrumental in FC action. Intriguingly, 14-3-3 affected both channels in an opposite fashion: whereas K(+) (in) channel activity was fully dependent upon 14-3-3 proteins, K(+) (out) channel activity was reduced by 14-3-3 proteins by 60%. Together with previous data showing that 14-3-3 proteins control the activity of the plasma membrane H(+)-ATPase, this makes 14-3-3 a prime candidate for molecular master regulator of the cellular osmo-pump. Regulation of the osmo-pump activity by ABA and FC is an important mechanism in controlling the growth of the embryonic root during seed germination.

  19. Abscisic acid-deficient sit tomato mutant responses to cadmium-induced stress.

    PubMed

    Pompeu, Georgia B; Vilhena, Milca B; Gratão, Priscila L; Carvalho, Rogério F; Rossi, Mônica L; Martinelli, Adriana P; Azevedo, Ricardo A

    2017-03-01

    There is a very effective cross-talk between signals triggered by reactive oxygen species and hormonal responses in plants, activating proteins/enzymes likely to be involved in stress tolerance. Abscisic acid (ABA) is known as a stress hormone that takes part in the integration of signals. This work aimed to characterize the biochemical response and ultrastructural changes induced by cadmium (Cd) in the Micro-Tom (MT) sitiens ABA-deficient mutant (sit) and its wild-type (MT) counterpart. MT and sit plants were grown over a 96-h period in the presence of Cd (0, 10, and 100 μM CdCl2). The overall results indicated increases in lipid peroxidation, hydrogen peroxide content and in the activities of the key antioxidant enzymes such as catalase, glutathione reductase, and ascorbate peroxidase in both genotypes. On the other hand, no alteration was observed in chlorophyll content, while the activity of another antioxidant enzyme, superoxide dismutase, remained constant or even decreased in the presence of Cd. Roots and shoots of the sit mutant and MT were analyzed by light and transmission electron microscopy in order to characterize the structural changes caused by the exposure to this metal. Cd caused a decrease in intercellular spaces in shoots and a decrease in cell size in roots of both genotypes. In leaves, Cd affected organelle shape and internal organization of the thylakoid membranes, whereas noticeable increase in the number of mitochondria and vacuoles in MT and sit roots were observed. These results add new information that should help unravel the relative importance of ABA in regulating the cell responses to stressful conditions induced by Cd apart from providing the first characterization of this mutant to oxidative stress.

  20. Exogenous Abscisic Acid Mimics Cold Acclimation for Cacti Differing in Freezing Tolerance.

    PubMed Central

    Loik, M. E.; Nobel, P. S.

    1993-01-01

    The responses to low temperature were determined for two species of cacti sensitive to freezing, Ferocactus viridescens and Opuntia ficus-indica, and a cold hardy species, Opuntia fragilis. Fourteen days after shifting the plants from day/night air temperatures of 30/20[deg]C to 10/0[deg]C, the chlorenchyma water content decreased only for O. fragilis. This temperature shift caused the freezing tolerance (measured by vital stain uptake) of chlorenchyma cells to be enhanced only by about 2.0[deg]C for F. viridescens and O. ficus-indica but by 14.6[deg]C for O. fragilis. Also, maintenance of high water content by injection of water into plants at 10/0[deg]C reversed the acclimation. The endogenous abscisic acid (ABA) concentration was below 0.4 pmol g-1 fresh weight at 30/20[deg]C, but after 14 d at 10/0[deg]C it increased to 84 pmol g-1 fresh weight for O. ficus-indica and to 49 pmol g-1 fresh weight for O. fragilis. Four days after plants were sprayed with 7.5 x 10-5 M ABA at 30/20[deg]C, freezing tolerance was enhanced by 0.5[deg]C for F. viridescens, 4.1[deg]C for O. ficus-indica, and 23.4[deg]C for O. fragilis. Moreover, the time course for the change in freezing tolerance over 14 d was similar for plants shifted to low temperatures as for plants treated with exogenous ABA at moderate temperatures. Decreases in plant water content and increases in ABA concentration may be important for low-temperature acclimation by cacti, especially O. fragilis, which is widely distributed in Canada and the United States. PMID:12231985

  1. Threshold response of stomatal closing ability to leaf abscisic acid concentration during growth.

    PubMed

    Giday, Habtamu; Fanourakis, Dimitrios; Kjaer, Katrine H; Fomsgaard, Inge S; Ottosen, Carl-Otto

    2014-08-01

    Leaf abscisic acid concentration ([ABA]) during growth influences morpho-physiological traits associated with the plant's ability to cope with stress. A dose-response curve between [ABA] during growth and the leaf's ability to regulate water loss during desiccation or rehydrate upon re-watering was obtained. Rosa hybrida plants were grown at two relative air humidities (RHs, 60% or 90%) under different soil water potentials (-0.01, -0.06, or -0.08MPa) or upon grafting onto the rootstock of a cultivar sustaining [ABA] at elevated RH. Measurements included [ABA], stomatal anatomical features, stomatal responsiveness to desiccation, and the ability of leaves, desiccated to varying degrees, to recover their weight (rehydrate) following re-watering. Transpiration efficiency (plant mass per transpired water) was also determined. Soil water deficit resulted in a lower transpiration rate and higher transpiration efficiency at both RHs. The lowest [ABA] was observed in well-watered plants grown at high RH. [ABA] was increased by soil water deficit or grafting, at both RHs. The growth environment-induced changes in stomatal size were mediated by [ABA]. When [ABA] was increased from the level of (well-watered) high RH-grown plants to the value of (well-watered) plants grown at moderate RH, stomatal responsiveness was proportionally improved. A further increase in [ABA] did not affect stomatal responsiveness to desiccation. [ABA] was positively related to the ability of dehydrated leaves to rehydrate. The data indicate a growth [ABA]-related threshold for stomatal sensitivity to desiccation, which was not apparent either for stomatal size or for recovery (rehydration) upon re-watering.

  2. Abscisic acid metabolism in relation to water stress and leaf age in Xanthium strumarium

    SciTech Connect

    Cornish, K.; Zeevaart, J.A.D.

    1984-12-01

    Intact plants of Xanthium strumarium L. were subjected to a water stress-recovery cycle. As the stress took effect, leaf growth ceased and stomatal resistance increased. The mature leaves then wilted, followed by the half expanded ones. Water, solute, and pressure potentials fell steadily in all leaves during the rest of the stress period. After 3 days, the young leaves lost turgor and the plants were rewatered. All the leaves rapidly regained turgor and the younger ones recommenced elongation. Stomatal resistance declined, but several days elapsed before pre-stress values were attained. Abscisic aid (ABA) and phaseic acid (PA) levels rose in all the leaves after the mature ones wilted. ABA-glucose ester (ABA-GE) levels increased to a lesser extent, and the young leaves contained little of this conjugate. PA leveled off in the older leaves during the last 24 hours of stress, and ABA levels declined slightly. The young leaves accumulated ABA and PA throughout the stress period and during the 14-hour period immediately following rewatering. The ABA and PA contents, expressed per unit dry weight, were highest in the young leaves. Upon rewatering, large quantities of PA appeared in the mature leaves as ABA levels fell to the pre-stress level within 14 hours. In the half expanded and young leaves, it took several days to reach pre-stress ABA values. ABA-GE synthesis ceased in the mature leaves, once the stress was relieved, but continued in the half expanded and young leaves for 2 days. Mature leaves, when detached and stressed, accumulated an amount of ABA similar to that in leaves on the intact plant. In contrast, detached and stressed young leaves produced little ABA. Studies with radioactive (+/-)-ABA indicated that in young leaves the conversion of ABA to PA took place at a much lower rate than in mature ones. 25 references, 10 figures, 2 tables.

  3. Abscisic Acid Induces Rapid Reductions in Mesophyll Conductance to Carbon Dioxide

    PubMed Central

    Sorrentino, Giuseppe; Haworth, Matthew; Wahbi, Said; Mahmood, Tariq; Zuomin, Shi; Centritto, Mauro

    2016-01-01

    The rate of photosynthesis (A) of plants exposed to water deficit is a function of stomatal (gs) and mesophyll (gm) conductance determining the availability of CO2 at the site of carboxylation within the chloroplast. Mesophyll conductance often represents the greatest impediment to photosynthetic uptake of CO2, and a crucial determinant of the photosynthetic effects of drought. Abscisic acid (ABA) plays a fundamental role in signalling and co-ordination of plant responses to drought; however, the effect of ABA on gm is not well-defined. Rose, cherry, olive and poplar were exposed to exogenous ABA and their leaf gas exchange parameters recorded over a four hour period. Application with ABA induced reductions in values of A, gs and gm in all four species. Reduced gm occurred within one hour of ABA treatment in three of the four analysed species; indicating that the effect of ABA on gm occurs on a shorter timescale than previously considered. These declines in gm values associated with ABA were not the result of physical changes in leaf properties due to altered turgor affecting movement of CO2, or caused by a reduction in the sub-stomatal concentration of CO2 (Ci). Increased [ABA] likely induces biochemical changes in the properties of the interface between the sub-stomatal air-space and mesophyll layer through the actions of cooporins to regulate the transport of CO2. The results of this study provide further evidence that gm is highly responsive to fluctuations in the external environment, and stress signals such as ABA induce co-ordinated modifications of both gs and gm in the regulation of photosynthesis. PMID:26862904

  4. Abscisic acid- and stress-induced highly proline-rich glycoproteins regulate root growth in rice.

    PubMed

    Tseng, I-Chieh; Hong, Chwan-Yang; Yu, Su-May; Ho, Tuan-Hua David

    2013-09-01

    In the root of rice (Oryza sativa), abscisic acid (ABA) treatment, salinity, or water deficit stress induces the expression of a family of four genes, REPETITIVE PROLINE-RICH PROTEIN (RePRP). These genes encode two subclasses of novel proline-rich glycoproteins with highly repetitive PX₁PX₂ motifs, RePRP1 and RePRP2. RePRP orthologs exist only in monocotyledonous plants, and their functions are virtually unknown. Rice RePRPs are heavily glycosylated with arabinose and glucose on multiple hydroxyproline residues. They are significantly different from arabinogalactan proteins that have glycan chains composed of arabinose and galactose. Transient and stable expressions of RePRP-green fluorescent protein reveal that a fraction of this protein is localized to the plasma membrane. In rice roots, ABA treatment increases RePRP expression preferentially in the elongation zone. Overexpression of RePRP in transgenic rice reduces root cell elongation in the absence of ABA, similar to the effect of ABA on wild-type roots. Conversely, simultaneous knockdown of the expression of RePRP1 and RePRP2 reduces the root sensitivity to ABA, indicating that RePRP proteins play an essential role in ABA/stress regulation of root growth and development. Moreover, rice RePRPs specifically interact with a polysaccharide, arabinogalactan, in a dosage-dependent manner. It is suggested that RePRP1 and RePRP2 are functionally redundant suppressors of root cell expansion and probably act through interactions with cell wall components near the plasma membrane.

  5. Exogenous Abscisic Acid Mimics Cold Acclimation for Cacti Differing in Freezing Tolerance.

    PubMed

    Loik, M. E.; Nobel, P. S.

    1993-11-01

    The responses to low temperature were determined for two species of cacti sensitive to freezing, Ferocactus viridescens and Opuntia ficus-indica, and a cold hardy species, Opuntia fragilis. Fourteen days after shifting the plants from day/night air temperatures of 30/20[deg]C to 10/0[deg]C, the chlorenchyma water content decreased only for O. fragilis. This temperature shift caused the freezing tolerance (measured by vital stain uptake) of chlorenchyma cells to be enhanced only by about 2.0[deg]C for F. viridescens and O. ficus-indica but by 14.6[deg]C for O. fragilis. Also, maintenance of high water content by injection of water into plants at 10/0[deg]C reversed the acclimation. The endogenous abscisic acid (ABA) concentration was below 0.4 pmol g-1 fresh weight at 30/20[deg]C, but after 14 d at 10/0[deg]C it increased to 84 pmol g-1 fresh weight for O. ficus-indica and to 49 pmol g-1 fresh weight for O. fragilis. Four days after plants were sprayed with 7.5 x 10-5 M ABA at 30/20[deg]C, freezing tolerance was enhanced by 0.5[deg]C for F. viridescens, 4.1[deg]C for O. ficus-indica, and 23.4[deg]C for O. fragilis. Moreover, the time course for the change in freezing tolerance over 14 d was similar for plants shifted to low temperatures as for plants treated with exogenous ABA at moderate temperatures. Decreases in plant water content and increases in ABA concentration may be important for low-temperature acclimation by cacti, especially O. fragilis, which is widely distributed in Canada and the United States.

  6. An Ancestral Role for CONSTITUTIVE TRIPLE RESPONSE1 Proteins in Both Ethylene and Abscisic Acid Signaling.

    PubMed

    Yasumura, Yuki; Pierik, Ronald; Kelly, Steven; Sakuta, Masaaki; Voesenek, Laurentius A C J; Harberd, Nicholas P

    2015-09-01

    Land plants have evolved adaptive regulatory mechanisms enabling the survival of environmental stresses associated with terrestrial life. Here, we focus on the evolution of the regulatory CONSTITUTIVE TRIPLE RESPONSE1 (CTR1) component of the ethylene signaling pathway that modulates stress-related changes in plant growth and development. First, we compare CTR1-like proteins from a bryophyte, Physcomitrella patens (representative of early divergent land plants), with those of more recently diverged lycophyte and angiosperm species (including Arabidopsis [Arabidopsis thaliana]) and identify a monophyletic CTR1 family. The fully sequenced P. patens genome encodes only a single member of this family (PpCTR1L). Next, we compare the functions of PpCTR1L with that of related angiosperm proteins. We show that, like angiosperm CTR1 proteins (e.g. AtCTR1 of Arabidopsis), PpCTR1L modulates downstream ethylene signaling via direct interaction with ethylene receptors. These functions, therefore, likely predate the divergence of the bryophytes from the land-plant lineage. However, we also show that PpCTR1L unexpectedly has dual functions and additionally modulates abscisic acid (ABA) signaling. In contrast, while AtCTR1 lacks detectable ABA signaling functions, Arabidopsis has during evolution acquired another homolog that is functionally distinct from AtCTR1. In conclusion, the roles of CTR1-related proteins appear to have functionally diversified during land-plant evolution, and angiosperm CTR1-related proteins appear to have lost an ancestral ABA signaling function. Our study provides new insights into how molecular events such as gene duplication and functional differentiation may have contributed to the adaptive evolution of regulatory mechanisms in plants.

  7. The Pepper CaOSR1 Protein Regulates the Osmotic Stress Response via Abscisic Acid Signaling.

    PubMed

    Park, Chanmi; Lim, Chae Woo; Lee, Sung Chul

    2016-01-01

    Plants are sessile organisms, and their growth and development is detrimentally affected by environmental stresses such as drought and high salinity. Defense mechanisms are tightly regulated and complex processes, which respond to changing environmental conditions; however, the precise mechanisms that function under adverse conditions remain unclear. Here, we report the identification and functional characterization of the CaOSR1 gene, which functions in the adaptive response to abiotic stress. We found that CaOSR1 gene expression in pepper leaves was up-regulated after exposure to abscisic acid (ABA), drought, and high salinity. In addition, we demonstrated that the fusion protein of CaOSR1 with green fluorescent protein (GFP) is localized in the nucleus. We used CaOSR1-silenced pepper plants and CaOSR1-OX-overexpressing (OX) transgenic Arabidopsis plants to show that the CaOSR1 protein regulates the osmotic stress response. CaOSR1-silenced pepper plants showed increased drought susceptibility, and this was accompanied by a high transpiration rate. CaOSR1-OX plants displayed phenotypes that were hypersensitive to ABA and hyposensitive to osmotic stress, during the seed germination and seedling growth stages; furthermore, these plants exhibited enhanced drought tolerance at the adult stage, and this was characterized by higher leaf temperatures and smaller stomatal apertures because of ABA hypersensitivity. Taken together, our data indicate that CaOSR1 positively regulates osmotic stress tolerance via ABA-mediated cell signaling. These findings suggest an involvement of a novel protein in ABA and osmotic stress signalings in plants.

  8. Molecular cloning, nucleotide sequence, and abscisic acid induction of a suberization-associated highly anionic peroxidase.

    PubMed

    Roberts, E; Kolattukudy, P E

    1989-06-01

    A highly anionic peroxidase induced in suberizing cells was suggested to be the key enzyme involved in polymerization of phenolic monomers to generate the aromatic matrix of suberin. The enzyme encoded by a potato cDNA was found to be highly homologous to the anionic peroxidase induced in suberizing tomato fruit. A tomato genomic library was screened using the potato anionic peroxidase cDNA and one genomic clone was isolated that contained two tandemly oriented anionic peroxidase genes. These genes were sequenced and were 96% and 87% identical to the mRNA for potato anionic peroxidase. Both genes consist of three exons with the relative positions of their two introns being conserved between the two genes. Primer extension analysis showed that only one of the genes is expressed in the periderm of 3 day wound-healed tomato fruits. Southern blot analyses suggested that there are two copies each of the two highly homologous genes per haploid genome in both potato and tomato. Abscisic acid (ABA) induced the accumulation of the anionic peroxidase transcripts in potato and tomato callus tissues. Northern blots showed that peroxidase mRNA was detectable at 2 days and was maximal at 8 days after transfer of potato callus to solid agar media containing 10(-4) M ABA. The transcripts induced by ABA in both potato and tomato callus were identical in size to those induced in wound-healing potato tuber and tomato fruit. The anionic peroxidase peptide was detected in extracts of potato callus grown on the ABA-containing media by western blot analysis. The results support the suggestion that stimulation of suberization by ABA involves the induction of the highly anionic peroxidase.

  9. Regulatory involvement of abscisic acid in potato tuber wound-healing.

    PubMed

    Lulai, Edward C; Suttle, Jeffrey C; Pederson, Shana M

    2008-01-01

    Rapid wound-healing is crucial in protecting potato tubers from infection and dehydration. Wound-induced suberization and the accumulation of hydrophobic barriers to reduce water vapour conductance/loss are principal protective wound-healing processes. However, little is known about the cognate mechanisms that effect or regulate these processes. The objective of this research was to determine the involvement of abscisic acid (ABA) in the regulation of wound-induced suberization and tuber water vapour loss (dehydration). Analysis by liquid chromatography-mass spectrometry showed that ABA concentrations varied little throughout the tuber, but were slightly higher near the periderm and lowest in the pith. ABA concentrations increase then decrease during tuber storage. Tuber wounding induced changes in ABA content. ABA content in wound-healing tuber discs decreased after wounding, reached a minimum by 24 h, and then increased from the 3rd to the 7th day after wounding. Wound-induced ABA accumulations were reduced by fluridone (FLD); an inhibitor of de novo ABA biosynthesis. Wound-induced phenylalanine ammonia lyase activity was slightly reduced and the accumulation of suberin poly(phenolics) and poly(aliphatics) noticeably reduced in FLD-treated tissues. Addition of ABA to the FLD treatment restored phenylalanine ammonia lyase activity and suberization, unequivocally indicating that endogenous ABA is involved in the regulation of these wound-healing processes. Similar experiments showed that endogenous ABA is involved in the regulation of water vapour loss, a process linked to wax accumulation in wound-healing tubers. Rapid reduction of water vapour loss across the wound surface is essential in preventing desiccation and death of cells at the wound site; live cells are required for suberization. These results unequivocally show that endogenous ABA is involved in the regulation of wound-induced suberization and the processes that protect surface cells from water vapour

  10. Patterns of auxin and abscisic acid movement in the tips of gravistimulated primary roots of maize

    NASA Technical Reports Server (NTRS)

    Young, L. M.; Evans, M. L.

    1996-01-01

    Because both abscisic acid (ABA) and auxin (IAA) have been suggested as possible chemical mediators of differential growth during root gravitropism, we compared with redistribution of label from applied 3H-IAA and 3H-ABA during maize root gravitropism and examined the relative basipetal movement of 3H-IAA and 3H-ABA applied to the caps of vertical roots. Lateral movement of 3H-ABA across the tips of vertical roots was non-polar and about 2-fold greater than lateral movement of 3H-IAA (also non-polar). The greater movement of ABA was not due to enhanced uptake since the uptake of 3H-IAA was greater than that of 3H-ABA. Basipetal movement of label from 3H-IAA or 3H-ABA applied to the root cap was determined by measuring radioactivity in successive 1 mm sections behind the tip 90 minutes after application. ABA remained largely in the first mm (point of application) whereas IAA was concentrated in the region 2-4 mm from the tip with substantial levels found 7-8 mm from the tip. Pretreatment with inhibitors of polar auxin transport decreased both gravicurvature and the basipetal movement of IAA. When roots were placed horizontally, the movement of 3H-IAA from top to bottom across the cap was enhanced relative to movement from bottom to top whereas the pattern of movement of label from 3H-ABA was unaffected. These results are consistent with the hypothesis that IAA plays a role in root gravitropism but contrary to the idea that gravi-induced asymmetric distribution of ABA contributes to the response.

  11. Involvement of Abscisic Acid in Regulating Water Status in Phaseolus vulgaris L. during Chilling 1

    PubMed Central

    Pardossi, Alberto; Vernieri, Paolo; Tognoni, Franco

    1992-01-01

    During the first hours of chilling, bean (Phaseolus vulgaris L., cv Mondragone) seedlings suffer severe water stress and wilt without any significant increase in leaf abscisic acid (ABA) content (P. Vernieri, A. Pardossi, F. Tognoni [1991] Aust J Plant Physiol 18: 25-35). Plants regain turgor after 30 to 40 h. We hypothesized that inability to rapidly synthesize ABA at low temperatures contributes to chilling-induced water stress and that turgor recovery after 30 to 40 h is mediated by changes in endogenous ABA content. Entire bean seedlings were subjected to long-term (up to 6 d) chilling (3°C, 0.2-0.4 kPa vapor pressure deficit, 100 μmol·m−2·s−1 photosynthetic photon flux density, continuous fluorescent light). During the first 24 h, stomata remained open, and plants rapidly wilted as leaf transpiration exceeded root water absorption. During this phase, ABA did not accumulate in leaves or in roots. After 24 h, ABA content increased in both tissues, leaf diffusion resistance increased, and plants rehydrated and regained turgor. No osmotic adjustment was associated with turgor recovery. Following turgor recovery, stomata remained closed, and ABA levels in both roots and leaves were elevated compared with controls. The application of ABA (0.1 mm) to the root system of the plants throughout exposure to 3°C prevented the chilling-induced water stress. Excised leaves fed 0.1 mm ABA via the transpiration stream had greater leaf diffusion resistance at 20 and 3°C compared with non-ABA fed controls, but the amount of ABA needed to elicit a given degree of stomatal closure was higher at 3°C compared with 20°C. These findings suggest that endogenous ABA may play a role in ameliorating plant water status during chilling. PMID:16653112

  12. Increasing abscisic acid levels by immunomodulation in barley grains induces precocious maturation without changing grain composition.

    PubMed

    Staroske, Nicole; Conrad, Udo; Kumlehn, Jochen; Hensel, Götz; Radchuk, Ruslana; Erban, Alexander; Kopka, Joachim; Weschke, Winfriede; Weber, Hans

    2016-04-01

    Abscisic acid (ABA) accumulates in seeds during the transition to the seed filling phase. ABA triggers seed maturation, storage activity, and stress signalling and tolerance. Immunomodulation was used to alter the ABA status in barley grains, with the resulting transgenic caryopses responding to the anti-ABA antibody gene expression with increased accumulation of ABA. Calculation of free versus antibody-bound ABA reveals large excess of free ABA, increasing signficantly in caryopses from 10 days after fertilization. Metabolite and transcript profiling in anti-ABA grains expose triggered and enhanced ABA-functions such as transcriptional up-regulation of sucrose-to-starch metabolism, storage protein synthesis and ABA-related signal transduction. Thus, enhanced ABA during transition phases induces precocious maturation but negatively interferes with growth and development. Anti-ABA grains display broad constitutive gene induction related to biotic and abiotic stresses. Most of these genes are ABA- and/or stress-inducible, including alcohol and aldehyde dehydrogenases, peroxidases, chaperones, glutathione-S-transferase, drought- and salt-inducible proteins. Conclusively, ABA immunomodulation results in precocious ABA accumulation that generates an integrated response of stress and maturation. Repression of ABA signalling, occurring in anti-ABA grains, potentially antagonizes effects caused by overshooting production. Finally, mature grain weight and composition are unchanged in anti-ABA plants, although germination is somewhat delayed. This indicates that anti-ABA caryopses induce specific mechanisms to desensitize ABA signalling efficiently, which finally yields mature grains with nearly unchanged dry weight and composition. Such compensation implicates the enormous physiological and metabolic flexibilities of barley grains to adjust effects of unnaturally high ABA amounts in order to ensure and maintain proper grain development.

  13. Identification of Interactions between Abscisic Acid and Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase

    PubMed Central

    Galka, Marek M.; Rajagopalan, Nandhakishore; Buhrow, Leann M.; Nelson, Ken M.; Switala, Jacek; Cutler, Adrian J.; Palmer, David R. J.; Loewen, Peter C.; Abrams, Suzanne R.; Loewen, Michele C.

    2015-01-01

    Abscisic acid ((+)-ABA) is a phytohormone involved in the modulation of developmental processes and stress responses in plants. A chemical proteomics approach using an ABA mimetic probe was combined with in vitro assays, isothermal titration calorimetry (ITC), x-ray crystallography and in silico modelling to identify putative (+)-ABA binding-proteins in crude extracts of Arabidopsis thaliana. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was identified as a putative ABA-binding protein. Radiolabelled-binding assays yielded a Kd of 47 nM for (+)-ABA binding to spinach Rubisco, which was validated by ITC, and found to be similar to reported and experimentally derived values for the native ribulose-1,5-bisphosphate (RuBP) substrate. Functionally, (+)-ABA caused only weak inhibition of Rubisco catalytic activity (Ki of 2.1 mM), but more potent inhibition of Rubisco activation (Ki of ~ 130 μM). Comparative structural analysis of Rubisco in the presence of (+)-ABA with RuBP in the active site revealed only a putative low occupancy (+)-ABA binding site on the surface of the large subunit at a location distal from the active site. However, subtle distortions in electron density in the binding pocket and in silico docking support the possibility of a higher affinity (+)-ABA binding site in the RuBP binding pocket. Overall we conclude that (+)-ABA interacts with Rubisco. While the low occupancy (+)-ABA binding site and weak non-competitive inhibition of catalysis may not be relevant, the high affinity site may allow ABA to act as a negative effector of Rubisco activation. PMID:26197050

  14. On the Role of Abscisic Acid and Gibberellin in the Regulation of Growth in Rice 1

    PubMed Central

    Hoffmann-Benning, Susanne; Kende, Hans

    1992-01-01

    Submergence induces rapid elongation of rice coleoptiles (Oryza sativa L.) and of deepwater rice internodes. This adaptive feature helps rice to grow out of the water and to survive flooding. Earlier, we found that the growth response of submerged deepwater rice plants is mediated by ethylene and gibberellin (GA). Ethylene promotes growth, at least in part, by increasing the responsiveness of the internodal tissue to GA. In the present work, we examined the possibility that increased responsiveness to GA was based on a reduction in endogenous abscisic acid (ABA) levels. Submergence and treatment with ethylene led, within 3 hours, to a 75% reduction in the level of ABA in the intercalary meristem and the growing zone of deepwater rice internodes. The level of GA1 increased fourfold during the same time period. An interaction between GA and ABA could also be shown by application of the hormones. ABA inhibited growth of submerged internodes, and GA counteracted this inhibition. Our results indicate that the growth rate of deepwater rice internodes is determined by the ratio of an endogenous growth promoter (GA) and a growth inhibitor (ABA). We also investigated whether ABA is involved in regulating the growth of rice coleoptiles. Rice seedlings were grown on solutions containing fluridone, an inhibitor of carotenoid and, indirectly, of ABA biosynthesis. Treatment with fluridone reduced the level of ABA in coleoptiles and first leaves by more than 75% and promoted coleoptile growth by more than 60%. Little or no enhancement of growth by fluridone was observed in barley, oat, or wheat. The involvement of ABA in determining the growth rate of rice coleoptiles and deepwater rice internodes may be related to the semiaquatic growth habit of this plant. PMID:16668983

  15. Abscisic acid metabolizing rhizobacteria decrease ABA concentrations in planta and alter plant growth.

    PubMed

    Belimov, Andrey A; Dodd, Ian C; Safronova, Vera I; Dumova, Valentina A; Shaposhnikov, Alexander I; Ladatko, Alexander G; Davies, William J

    2014-01-01

    Although endogenous phytohormones such as abscisic acid (ABA) regulate root growth, and many rhizobacteria can modulate root phytohormone status, hitherto there have been no reports of rhizobacteria mediating root ABA concentrations and growth by metabolising ABA. Using a selective ABA-supplemented medium, two bacterial strains were isolated from the rhizosphere of rice (Oryza sativa) seedlings grown in sod-podzolic soil and assigned to Rhodococcus sp. P1Y and Novosphingobium sp. P6W using partial 16S rRNA gene sequencing and phenotypic patterns by the GEN III MicroPlate test. Although strain P6W had more rapid growth in ABA-supplemented media than strain P1Y, both could utilize ABA as a sole carbon source in batch culture. When rice seeds were germinated on filter paper in association with bacteria, root ABA concentration was not affected, but shoot ABA concentration of inoculated plants decreased by 14% (strain P6W) and 22% (strain P1Y). When tomato (Solanum lycopersicum) genotypes differing in ABA biosynthesis (ABA deficient mutants flacca - flc, and notabilis - not and the wild-type cv. Ailsa Craig, WT) were grown in gnotobiotic cultures on nutrient solution agar, rhizobacterial inoculation decreased root and/or leaf ABA concentrations, depending on plant and bacteria genotypes. Strain P6W inhibited primary root elongation of all genotypes, but increased leaf biomass of WT plants. In WT plants treated with silver ions that inhibit ethylene perception, both ABA-metabolising strains significantly decreased root ABA concentration, and strain P6W decreased leaf ABA concentration. Since these changes in ABA status also occurred in plants that were not treated with silver, it suggests that ethylene was probably not involved in regulating bacteria-mediated changes in ABA concentration. Correlations between plant growth and ABA concentrations in planta suggest that ABA-metabolising rhizobacteria may stimulate growth via an ABA-dependent mechanism.

  16. Role of Abscisic Acid in the Induction of Desiccation Tolerance in Developing Seeds of Arabidopsis thaliana

    PubMed Central

    Meurs, Cor; Basra, Amarjit S.; Karssen, Cees M.; van Loon, Leendert C.

    1992-01-01

    In contrast to wild-type seeds of Arabidopsis thaliana and to seeds deficient in (aba) or insensitive to (abi3) abscisic acid (ABA), maturing seeds of recombinant (aba,abi3) plants fail to desiccate, remain green, and lose viability upon drying. These double-mutant seeds acquire only low levels of the major storage proteins and are deficient in several low mol wt polypeptides, both soluble and bound, and some of which are heat stable. A major heat-stable glycoprotein of more than 100 kilodaltons behaves similarly; during seed development, it shows a decrease in size associated with the abi3 mutation. In seeds of the double mutant from 14 to 20 days after pollination, the low amounts of various maturation-specific proteins disappear and many higher mol wt proteins similar to those occurring during germination are induced, but no visible germination is apparent. It appears that in the aba,abi3 double mutant seed development is not completed and the program for seed germination is initiated prematurely in the absence of substances protective against dehydration. Seeds may be made desiccation tolerant by watering the plants with the ABA analog LAB 173711 or by imbibition of isolated immature seeds, 11 to 15 days after pollination, with ABA and sucrose. Whereas sucrose stimulates germination and may protect dehydration-sensitive structures from desiccation damage, ABA inhibits precocious germination and is required to complete the program for seed maturation and the associated development of desiccation tolerance. ImagesFigure 1Figure 2Figure 4Figure 5Figure 6Figure 8 PMID:16668818

  17. Homologous Recombination Defective Arabidopsis Mutants Exhibit Enhanced Sensitivity to Abscisic Acid

    PubMed Central

    Roy, Sujit; Das, Kali Pada

    2017-01-01

    Abscisic acid (ABA) acts as an important plant hormone in regulating various aspects of plant growth and developmental processes particularly under abiotic stress conditions. An increased ABA level in plant cells inhibits DNA replication and cell division, causing plant growth retardation. In this study, we have investigated the effects of ABA on the growth responses of some major loss-of-function mutants of DNA double-stand break (DSB) repair genes in Arabidopsis during seed germination and early stages of seedling growth for understanding the role of ABA in the induction of genome instability in plants. A comparative analysis of ABA sensitivity of wild-type Arabidopsis and the knockout mutant lines related to DSB sensors, including atatm, atatr, the non-homologous end joining (NHEJ) pathway genes, and mutants related to homologous recombination (HR) pathway genes showed relatively enhanced sensitivity of atatr and HR-related mutants to ABA treatment. The expression levels of HR-related genes were increased in wild-type Arabidopsis (Col-0) during seed germination and early stages of seedling growth. Immunoblotting experiments detected phosphorylation of histone H2AX in wild-type (Col-0) and DSB repair gene mutants after ABA treatment, indicating the activation of DNA damage response due to ABA treatment. Analyses of DSB repair kinetics using comet assay under neutral condition have revealed comparatively slower DSB repair activity in HR mutants. Overall, our results have provided comprehensive information on the possible effect of ABA on DNA repair machinery in plants and also indicated potential functional involvement of HR pathway in repairing ABA induced DNA damage in Arabidopsis. PMID:28046013

  18. Abscisic acid root and leaf concentration in relation to biomass partitioning in salinized tomato plants.

    PubMed

    Lovelli, Stella; Scopa, Antonio; Perniola, Michele; Di Tommaso, Teodoro; Sofo, Adriano

    2012-02-15

    Salinization is one of the most important causes of crop productivity reduction in many areas of the world. Mechanisms that control leaf growth and shoot development under the osmotic phase of salinity are still obscure, and opinions differ regarding the Abscisic acid (ABA) role in regulation of biomass allocation under salt stress. ABA concentration in roots and leaves was analyzed in a genotype of processing tomato under two increasing levels of salinity stress for five weeks: 100 mM NaCl (S10) and 150 mM NaCl (S15), to study the effect of ABA changes on leaf gas exchange and dry matter partitioning of this crop under salinity conditions. In S15, salinization decreased dry matter by 78% and induced significant increases of Na(+) and Cl(-) in both leaves and roots. Dry matter allocated in different parts of plant was significantly different in salt-stressed treatments, as salinization increased root/shoot ratio 2-fold in S15 and 3-fold in S15 compared to the control. Total leaf water potential (Ψ(w)) decreased from an average value of approximately -1.0 MPa, measured on control plants and S10, to -1.17 MPa in S15. In S15, photosynthesis was reduced by 23% and stomatal conductance decreased by 61%. Moreover, salinity induced ABA accumulation both in tomato leaves and roots of the more stressed treatment (S15), where ABA level was higher in roots than in leaves (550 and 312 ng g(-1) fresh weight, respectively). Our results suggest that the dynamics of ABA and ion accumulation in tomato leaves significantly affected both growth and gas exchange-related parameters in tomato. In particular, ABA appeared to be involved in the tomato salinity response and could play an important role in dry matter partitioning between roots and shoots of tomato plants subjected to salt stress.

  19. Abscisic acid in salt stress predisposition to phytophthora root and crown rot in tomato and chrysanthemum.

    PubMed

    Dileo, Matthew V; Pye, Matthew F; Roubtsova, Tatiana V; Duniway, John M; Macdonald, James D; Rizzo, David M; Bostock, Richard M

    2010-09-01

    Plants respond to changes in the environment with complex signaling networks, often under control of phytohormones that generate positive and negative crosstalk among downstream effectors of the response. Accordingly, brief dehydration stresses such as salinity and water deficit, which induce a rapid and transient systemic increase in levels of abscisic acid (ABA), can influence disease response pathways. ABA has been associated with susceptibility of plants to bacteria, fungi, and oomycetes but relatively little attention has been directed at its role in abiotic stress predisposition to root pathogens. This study examines the impact of brief salinity stress on infection of tomato and chrysanthemum roots by Phytophthora spp. Roots of plants in hydroponic culture exposed to a brief episode of salt (sodium chloride) stress prior to or after inoculation were severely diseased relative to nonstressed plants. Tomato roots remained in a predisposed state up to 24 h following removal from the stress. An increase in root ABA levels in tomato preceded or temporally paralleled the onset of stress-induced susceptibility, with levels declining in roots prior to recovery from the predisposed state. Exogenous ABA could substitute for salt stress and significantly enhanced pathogen colonization and disease development. ABA-deficient tomato mutants lacked the predisposition response, which could be restored by complementation of the mutant with exogenous ABA. In contrast, ethylene, which exacerbates disease symptoms in some host-parasite interactions, did not appear to contribute to the predisposition response. Thus, several lines of evidence support ABA as a critical and dominant factor in the salinity-induced predisposition to Phytophthora spp. infection.

  20. Abscisic acid and transpiration rate are involved in the response to boron toxicity in Arabidopsis plants.

    PubMed

    Macho-Rivero, Miguel Ángel; Camacho-Cristóbal, Juan José; Herrera-Rodríguez, María Begoña; Müller, Maren; Munné-Bosch, Sergi; González-Fontes, Agustín

    2016-12-09

    Boron (B) is an essential microelement for vascular plant development, but its toxicity is a major problem affecting crop yields in arid and semi-arid areas of the world. In the literature, several genes involved in abscisic acid (ABA) signalling and responses are upregulated in Arabidopsis roots after treatment with excess B. It is known that the AtNCED3 gene, which encodes a crucial enzyme for ABA biosynthesis, plays a key role in the plant response to drought stress. In this study, root AtNCED3 expression and shoot ABA content were rapidly increased in wild-type plants upon B-toxicity treatment. The Arabidopsis ABA-deficient nced3-2 mutant had higher transpiration rate, stomatal conductance and accumulated more B in their shoots than wild-type plants, facts that were associated with the lower levels of ABA in this mutant. However, in wild-type plants, B toxicity caused a significant reduction in stomatal conductance, resulting in a decreased transpiration rate. This response could be a mechanism to limit the transport of excess B from the roots to the leaves under B toxicity. In agreement with the higher transpiration rate of the nced3-2 mutant, this genotype showed an increased leaf B concentration and damage upon exposure to 5 mM B. Under B toxicity, ABA application decreased B accumulation in wild-type and nced3-2 plants. In summary, this work shows that excess B applied to the roots leads to rapid changes in AtNCED3 expression and gas exchange parameters that would contribute to restrain the B entry into the leaves, this effect being mediated by ABA.

  1. 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.

  2. 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).

  3. Abscisic acid regulates seed germination of Vellozia species in response to temperature.

    PubMed

    Vieira, B C; Bicalho, E M; Munné-Bosch, S; Garcia, Q S

    2017-03-01

    The relationship between the phytohormones, gibberellin (GA) and abscisic acid (ABA) and light and temperature on seed germination is still not well understood. We aimed to investigate the role of the ABA and GA on seed germination of Vellozia caruncularis, V. intermedia and V. alutacea in response to light/dark conditions on different temperature. Seeds were incubated in GA (GA3 or GA4 ) or ABA and their respective biosynthesis inhibitors (paclobutrazol - PAC, and fluridone - FLU) solutions at two contrasting temperatures (25 and 40 °C). Furthermore, endogenous concentrations of active GAs and those of ABA were measured in seeds of V. intermedia and V. alutacea during imbibition/germination. Exogenous ABA inhibited the germination of Vellozia species under all conditions tested. GA, FLU and FLU + GA3 stimulated germination in the dark at 25 °C (GA4 being more effective than GA3 ). PAC reduced seed germination in V. caruncularis and V. alutacea, but did not affect germination of V. intermedia at 40 °C either under light or dark conditions. During imbibition in the dark, levels of active GAs decreased in the seeds of V. intermedia, but were not altered in those of V. alutacea. Incubation at 40 °C decreased ABA levels during imbibition in both V. caruncularis and V. alutacea. We conclude that the seeds of Vellozia species studied here require light or high temperature to germinate and ABA has a major role in the regulation of Vellozia seed germination in response to light and temperature.

  4. Stomatal response of an anisohydric grapevine cultivar to evaporative demand, available soil moisture and abscisic acid.

    PubMed

    Rogiers, Suzy Y; Greer, Dennis H; Hatfield, Jo M; Hutton, Ron J; Clarke, Simon J; Hutchinson, Paul A; Somers, Anthony

    2012-03-01

    Stomatal responsiveness to evaporative demand (air vapour pressure deficit (VPD)) ranges widely between species and cultivars, and mechanisms for stomatal control in response to VPD remain obscure. The interaction of irrigation and soil moisture with VPD on stomatal conductance is particularly difficult to predict, but nevertheless is critical to instantaneous transpiration and vulnerability to desiccation. Stomatal sensitivity to VPD and soil moisture was investigated in Semillon, an anisohydric Vitis vinifera L. variety whose leaf water potential (Ψ(l)) is frequently lower than that of other grapevine varieties grown under similar conditions in the warm grape-growing regions of Australia. A survey of Semillon vines across seven vineyards revealed that, regardless of irrigation treatment, midday Ψ(l) was dependent on not only soil moisture but VPD at the time of measurement. Predawn Ψ(l) was more closely correlated to not only soil moisture in dry vineyards but to night-time VPD in drip-irrigated vineyards, with incomplete rehydration during high night-time VPD. Daytime stomatal conductance was low only under severe plant water deficits, induced by extremes in dry soil. Stomatal response to VPD was inconsistent across irrigation regime; however, in an unirrigated vineyard, stomatal sensitivity to VPD-the magnitude of stomatal response to VPD-was heightened under dry soils. It was also found that stomatal sensitivity was proportional to the magnitude of stomatal conductance at a reference VPD of 1kPa. Exogenous abscisic acid (ABA) applied to roots of Semillon vines growing in a hydroponic system induced stomatal closure and, in field vines, petiole xylem sap ABA concentrations rose throughout the morning and were higher in vines with low Ψ(l). These data indicate that despite high stomatal conductance of this anisohydric variety when grown in medium to high soil moisture, increased concentrations of ABA as a result of very limited soil moisture may augment

  5. Beyond plant defense: insights on the potential of salicylic and methylsalicylic acid to contain growth of the phytopathogen Botrytis cinerea

    PubMed Central

    Dieryckx, Cindy; Gaudin, Vanessa; Dupuy, Jean-William; Bonneu, Marc; Girard, Vincent; Job, Dominique

    2015-01-01

    Using Botrytis cinerea we confirmed in the present work several previous studies showing that salicylic acid, a main plant hormone, inhibits fungal growth in vitro. Such an inhibitory effect was also observed for the two salicylic acid derivatives, methylsalicylic and acetylsalicylic acid. In marked contrast, 5-sulfosalicylic acid was totally inactive. Comparative proteomics from treated vs. control mycelia showed that both the intracellular and extracellular proteomes were affected in the presence of salicylic acid or methylsalicylic acid. These data suggest several mechanisms that could potentially account for the observed fungal growth inhibition, notably pH regulation, metal homeostasis, mitochondrial respiration, ROS accumulation and cell wall remodeling. The present observations support a role played by the phytohormone SA and derivatives in directly containing the pathogen. Data are available via ProteomeXchange with identifier PXD002873. PMID:26528317

  6. Cross-talk between gibberellins and salicylic acid in early stress responses in Arabidopsis thaliana seeds

    PubMed Central

    Alonso-Ramírez, Ana; Rodríguez, Dolores; Reyes, David; Jiménez, Jesús Angel; Nicolás, Gregorio; López-Climent, María; Gómez-Cadenas, Aurelio

    2009-01-01

    Salicylic acid (SA) is a plant hormone mainly associated with the induction of defense mechanism in plants, although in the last years there is increasing evidence on the role of SA in plant responses to abiotic stress. We recently reported that an increase in endogenous SA levels are able to counteract the inhibitory effects of several abiotic stress conditions during germination and seedling establishment of Arabidopsis thaliana and that this effect is modulated by gibberellins (GAs) probably through a member of the GASA (Giberellic Acid Stimulated in Arabidopsis) gene family, clearly showing the existence of a cross talk between these two plant hormones in Arabidopsis. PMID:19820299

  7. Effects of salicylic acid and putrescine on storability, quality attributes and antioxidant activity of plum cv. 'Santa Rosa'.

    PubMed

    Davarynejad, Gholam Hossein; Zarei, Mehdi; Nasrabadi, Mohamad Ebrahim; Ardakani, Elham

    2015-04-01

    Plum fruit has a short shelf life with a rapid deterioration in quality after harvest. The primary goal of this study is to investigate and compare the effect of putrescine and salicylic acid on quality properties and antioxidant activity of plum during storage. The plum fruits (cv. 'Santa Rosa') were harvested at the mature ripe stage, and dipped in different concentrations of putrescine (1, 2, 3 and 4 mmol/L) and salicylic acid (1, 2, 3 and 4 mmol/L), as well as distilled water (control) for 5 min. The fruits were then packed in boxes with polyethylene covers and stored at 4 °C with 95 % relative humidity for 25 days. A factorial trial based on completely randomized block design with 4 replications was carried out. The weight loss, fruit firmness, total soluble solids, titratable acidity, pH, maturity index, ascorbic acid, total phenolics and antioxidant activity at 0, 5, 10, 15, 20 and 25 days after harvest were recorded. During the storage period, the weight loss, total soluble solids, pH and maturity index increased significantly while the fruit firmness, titratable acidity, ascorbic acid, total phenolics and antioxidant activity decreased significantly (P < 0.05) for all treatments. Statistically significant differences were observed between different treatments (putrescine, salicylic acid and control) in all measured parameters. The data showed that the weight loss and softening of the plum fruits were decreased significantly by the use of putrescine and salicylic acid. Also, exogenous treatments of putrescine and salicylic acid are found to be effective in maintaining titratable acidity, ascorbic acid, total phenolics and antioxidant activity in plum fruits during storage at 4 °C. It was concluded that postharvest treatment of plum fruit with putrescine and salicylic acid were effective on delaying the ripening processes and can be used commercially to extend the shelf life of plum fruit with acceptable fruit quality.

  8. Differential effects of some natural compounds on the transdermal absorption and penetration of caffeine and salicylic acid.

    PubMed

    Muhammad, Faqir; Riviere, Jim E

    2015-04-10

    Many natural products have the potential to modulate the dermal penetration of topically applied drugs and chemicals. We studied the effect of five natural compounds (hydroxycitronellal, limonene 1,2-epoxide, terpinyl acetate, p-coumaric acid, transferrulic acid) and ethanol on the transdermal penetration of two marker drugs ((14)C-caffeine and (14)C-salicylic acid) in a flow through in vitro porcine skin diffusion system. The parameters of flux, permeability, diffusivity, and percent dose absorbed/retained were calculated and compared. The dermal absorption of (14)C-caffeine was significantly higher with terpinyl acetate and limonene 1,2-epoxide as compared to ethanol; while dermal absorption of (14)C-salicylic acid was significantly greater with hydroxycitronellal and limonene 1,2-epoxide as compared to ethanol. A 10-fold increase in flux and permeability of caffeine with terpinyl acetate was observed while limonene increased flux of caffeine by 4-fold and permeability by 3-fold. Hydroxycitronellal and limonene increased salicylic acid's flux and permeability over 2-fold. The other natural compounds tested did not produce statistically significant effects on dermal penetration parameters for both caffeine and salicylic acid (p≥0.05). These results emphasize the differential effects of natural substances on the transdermal penetration of hydrophilic (caffeine) and hydrophobic (salicylic acid) drugs.

  9. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci

    PubMed Central

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles—especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  10. Expression of salicylic acid-related genes in Brassica oleracea var. capitata during Plasmodiophora brassicae infection.

    PubMed

    Manoharan, Ranjith Kumar; Shanmugam, Ashokraj; Hwang, Indeok; Park, Jong-In; Nou, Ill-Sup

    2016-06-01

    Brassica oleracea var. capitata (cabbage) is an important vegetable crop in Asian countries such as Korea, China, and Japan. Cabbage production is severely affected by clubroot disease caused by the soil-borne plant pathogen Plasmodiophora brassicae. During clubroot development, methyl salicylate (MeSA) is biosynthesized from salicylic acid (SA) by methyltransferase. In addition, methyl salicylate esterase (MES) plays a major role in the conversion of MeSA back into free SA. The interrelationship between MES and methytransferases during clubroot development has not been fully explored. To begin to examine these relationships, we investigated the expression of MES genes in disease-susceptible and disease-resistant plants during clubroot development. We identified three MES-encoding genes potentially involved in the defense against pathogen attack. We found that SS1 was upregulated in both the leaves and roots of B. oleracea during P. brassicae infection. These results support the conclusion that SA biosynthesis is suppressed during pathogen infection in resistant plants. We also characterized the expression of a B. oleracea BSMT gene, which appears to be involved in glycosylation rather than MeSA biosynthesis. Our results provide insight into the functions and interactions of genes for MES and methyltransferase during infection. Taken together, our findings indicate that MES genes are important candidates for use to control clubroot diseases.

  11. Studies on the growth and indole-3-acetic acid and abscisic acid content of Zea mays seedlings grown in microgravity

    NASA Technical Reports Server (NTRS)

    Schulze, A.; Jensen, P. J.; Desrosiers, M.; Buta, J. G.; Bandurski, R. S.

    1992-01-01

    Measurements were made of the fresh weight, dry weight, dry weight-fresh weight ratio, free and conjugated indole-3-acetic acid, and free and conjugated abscisic acid in seedlings of Zea mays grown in darkness in microgravity and on earth. Imbibition of the dry kernels was 17 h prior to launch. Growth was for 5 d at ambient orbiter temperature and at a chronic accelerational force of the order of 3 x 10(-5) times earth gravity. Weights and hormone content of the microgravity seedlings were, with minor exceptions, not statistically different from seedlings grown in normal gravity. The tissues of the shuttle-grown plants appeared normal and the seedlings differed only in the lack of orientation of roots and shoots. These findings, based upon 5 d of growth in microgravity, cannot be extrapolated to growth in microgravity for weeks, months, and years, as might occur on a space station. Nonetheless, it is encouraging, for prospects of bioregeneration of the atmosphere and food production in a space station, that no pronounced differences in the parameters measured were apparent during the 5 d of plant seedling growth in microgravity.

  12. Ascorbic acid and reactive oxygen species are involved in the inhibition of seed germination by abscisic acid in rice seeds.

    PubMed

    Ye, Nenghui; Zhu, Guohui; Liu, Yinggao; Zhang, Aying; Li, Yingxuan; Liu, Rui; Shi, Lu; Jia, Liguo; Zhang, Jianhua

    2012-03-01

    The antagonism between abscisic acid (ABA) and gibberellin (GA) plays a key role in controlling seed germination, but the mechanism of antagonism during this process is not known. The possible links among ABA, reactive oxygen species (ROS), ascorbic acid (ASC), and GA during rice seed germination were investigated. Unlike in non-seed tissues where ROS production is increased by ABA, ABA reduced ROS production in imbibed rice seeds, especially in the embryo region. Such reduced ROS also led to an inhibition of ASC production. GA accumulation was also suppressed by a reduced ROS and ASC level, which was indicated by the inhibited expression of GA biosynthesis genes, amylase genes, and enzyme activity. Application of exogenous ASC can partially rescue seed germination from ABA treatment. Production of ASC, which acts as a substrate in GA biosynthesis, was significantly inhibited by lycorine which thus suppressed the accumulation of GA. Consequently, expression of GA biosynthesis genes was suppressed by the low levels of ROS and ASC in ABA-treated seeds. It can be concluded that ABA regulates seed germination in multiple dimensions. ROS and ASC are involved in its inhibition of GA biosynthesis.

  13. Growth and graviresponsiveness of primary roots of Zea mays seedlings deficient in abscisic acid and gibberellic acid

    NASA Technical Reports Server (NTRS)

    Moore, R.; Dickey, K.

    1985-01-01

    The objective of this research was to determine if gibberellic acid (GA) and/or abscisic acid (ABA) are necessary for graviresponsiveness by primary roots of Zea mays. To accomplish this objective we measured the growth and graviresponsiveness of primary roots of seedlings in which the synthesis of ABA and GA was inhibited collectively and individually by genetic and chemical means. Roots of seedlings treated with Fluridone (an inhibitor of ABA biosynthesis) and Ancymidol (an inhibitor of GA biosynthesis) were characterized by slower growth rates but not significantly different gravicultures as compared to untreated controls. Gravicurvatures of primary roots of d-5 mutants (having undetectable levels of GA) and vp-9 mutants (having undectable levels of ABA) were not significantly different from those of wild-type seedlings. Roots of seedlings in which the biosynthesis of ABA and GA was collectively inhibited were characterized by gravicurvatures not significantly different for those of controls. These results (1) indicate that drastic reductions in the amount of ABA and GA in Z. mays seedlings do not significantly alter root graviresponsiveness, (2) suggest that neither ABA nor GA is necessary for root gravicurvature, and (3) indicate that root gravicurvature is not necessarily proportional to root elongation.

  14. Thermodynamics of sodium dodecyl sulphate-salicylic acid based micellar systems and their potential use in fruits postharvest.

    PubMed

    Cid, A; Morales, J; Mejuto, J C; Briz-Cid, N; Rial-Otero, R; Simal-Gándara, J

    2014-05-15

    Micellar systems have excellent food applications due to their capability to solubilise a large range of hydrophilic and hydrophobic substances. In this work, the mixed micelle formation between the ionic surfactant sodium dodecyl sulphate (SDS) and the phenolic acid salicylic acid have been studied at several temperatures in aqueous solution. The critical micelle concentration and the micellization degree were determined by conductometric techniques and the experimental data used to calculate several useful thermodynamic parameters, like standard free energy, enthalpy and entropy of micelle formation. Salicylic acid helps the micellization of SDS, both by increasing the additive concentration at a constant temperature and by increasing temperature at a constant concentration of additive. The formation of micelles of SDS in the presence of salicylic acid was a thermodynamically spontaneous process, and is also entropically controlled. Salicylic acid plays the role of a stabilizer, and gives a pathway to control the three-dimensional water matrix structure. The driving force of the micellization process is provided by the hydrophobic interactions. The isostructural temperature was found to be 307.5 K for the mixed micellar system. This article explores the use of SDS-salicylic acid based micellar systems for their potential use in fruits postharvest.

  15. 75 FR 11740 - S-Abscisic Acid, (S)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-1-cyclohex-2-enyl)-3-methyl-penta-(2Z,4E...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... AGENCY 40 CFR Part 180 S-Abscisic Acid, (S)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-1- cyclohex-2-enyl)-3-methyl-penta-(2Z,4E)-dienoic Acid; Amendment to an Exemption from the Requirement of a Tolerance AGENCY... exemption from the requirement of a tolerance for residues of the biochemical pesticide S-Abscisic Acid,...

  16. Roles of gibberellins and abscisic acid in dormancy and germination of red bayberry (Myrica rubra) seeds.

    PubMed

    Chen, Shun-Ying; Kuo, Shing-Rong; Chien, Ching-Te

    2008-09-01

    Intact seeds from freshly harvested fruits of Myrica rubra (Sieb et Zucc.) were dormant and required 8 weeks of warm stratification followed by 12 weeks of cold stratification for germination. Exogenous application of gibberellic acid (GA(3)) to intact fresh seeds was effective in breaking dormancy, with > 70% of seeds germinating when treated with 5.2 mM GA(3) and incubated at a day/night temperature of 30/20 degrees C for 20 weeks. Removing the hard endocarp or endocarp plus seed coat of fresh seeds promoted germination, and addition of GA(3) to the embryo accelerated germination. The gibberellins GA(1) and GA(4) were more effective than GA(3) in promoting germination of seeds with the endocarp removed. Endogenous contents of GA(1), GA(3), GA(4), GA(7) and GA(20) were quantified by gas chromatography-mass spectrometry-selected ion monitoring in the endocarps, seed coats and embryos of fresh seeds treated with 5.2 mM GA(3). The content of GA(3) decreased in the endocarp during incubation, whereas GA(1) contents increased in the endocarp and seed coat. A high GA(1) content was detected in the endocarps and embryos of newly germinated seeds. We speculate that GA(3) was converted to GA(1) during incubation and that GA(1) is involved in seed germination. Endogenous abscisic acid (ABA) contents were measured in fresh seeds and in warm and cold stratified seeds. The ABA content in fresh seeds was distributed in the order endocarp > seed coat > embryo, with the content in the endocarp being about 132-fold higher than in the seed coat and embryo. Total ABA content of seeds subjected to warm or cold stratification, or both, was 8.7- to 14.0-fold lower than that of fresh seeds. Low contents of endogenous GA(1), GA(3), GA(7) and GA(20), but elevated contents of GA(4), were found in the seed coats and endocarps of warm plus cold stratified seeds and in the seed coats and embryos of newly germinated seeds. These observations, coupled with the finding that GA stimulated

  17. Nanocarrier-based hydrogel of betamethasone dipropionate and salicylic acid for treatment of psoriasis

    PubMed Central

    Baboota, Sanjula; Alam, Md Sarfaraz; Sharma, Shrestha; Sahni, Jasjeet K; Kumar, Anil; Ali, Javed

    2011-01-01

    Introduction: Betamethasone dipropionate (BD) has anti-inflammatory, immunomodulatory, and antiproliferative activity. The aim of the current work was to test the hypothesis that the addition of corticosteroid such as BD and a keratolytic agent such as salicylic acid in nanocarrier based microemulsions formulation would result in enhancement and sustaining of corticosteroid delivery rate leading to better anti-psoriatic activity. Clinical use of BD is restricted to some extent due to its poor permeability across the skin. So to increase its permeation across the skin, microemulsion-based gel formulations were prepared and characterised. Materials and Methods: Microemulsions were prepared by aqueous phase titration method, using oleic acid:sefsol (1.5:1), Tween 20, isopropyl alcohol, and distilled water as the oil phase, surfactant, cosurfactant and aqueous phase, respectively. Selected formulations were subjected to physical stability studies and consequently in vitro skin permeation studies. Surface studies of optimized formulation were done by transmission electron microscopy. In vivo anti-inflammatory activity was done by carageenan-induced raw paw edema method. Results: The droplet size of microemulsions ranged from 60 to 190 nm. The optimized formulation exhibited viscosity 28.55 ± 2.03 mP, refractive index 1.409, pH 6.4, and conductivity 10-4 scm-1. The optimized microemulsion was converted into hydrogel using carbopol 934, and salicylic acid was incorporated into it. Drug deposition in skin was found to be 29.73 μg/mg. Assessment of skin permeation was done by histopathology studies which indicated changes in the structure of epidermal membrane of skin. In vivo anti-inflammatory activity indicated 72.11% and 43.96% inhibition of inflammation in case of developed microemulsion gel and marketed gel, respectively. Conclusions: The developed microemulsion gel containing BD and salicylic acid provided sustained and good anti-inflammatory activity for the

  18. Spatio-temporal changes in endogenous abscisic acid contents during etiolated growth and photomorphogenesis in tomato seedlings

    PubMed Central

    Humplík, Jan F; Turečková, Veronika; Fellner, Martin; Bergougnoux, Véronique

    2015-01-01

    The role of abscisic acid (ABA) during early development was investigated in tomato seedlings. The endogenous content of ABA in particular organs was analyzed in seedlings grown in the dark and under blue light. Our results showed that in dark-grown seedlings, the ABA accumulation was maximal in the cotyledons and elongation zone of hypocotyl, whereas under blue-light, the ABA content was distinctly reduced. Our data are consistent with the conclusion that ABA promotes the growth of etiolated seedlings and the results suggest that ABA plays an inhibitory role in de-etiolation and photomorphogenesis in tomato. PMID:26322576

  19. Detection of Salicylic Acid in Willow Bark: An Addition to a Classic Series of Experiments in the Introductory Organic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Clay, Matthew D.; McLeod, Eric J.

    2012-01-01

    Salicylic acid and its derivative, acetylsalicylic acid, are often encountered in introductory organic chemistry experiments, and mention is often made that salicylic acid was originally isolated from the bark of the willow tree. This biological connection, however, is typically not further pursued, leaving students with an impression that biology…

  20. Salicylic acid changes the properties of extracellular peroxidase activity secreted from wounded wheat (Triticum aestivum L.) roots.

    PubMed

    Minibayeva, F; Mika, A; Lüthje, S

    2003-05-01

    Wheat ( Triticum aestivum L.) roots released proteins showing peroxidase activity in the apoplastic solution in response to wound stress. Preincubation of excised roots with 1 mM salicylic acid at pH 7.0 enhanced the guaiacol peroxidase activity of the extracellular solution (so-called extracellular peroxidase). The soluble enzymes were partially purified by precipitation with ammonium sulfate followed by size exclusion and ion exchange chromatography. Despite an increase in the total activity of secreted peroxidase induced by pretreatment of excised roots with salicylic acid, the specific activity of the partially purified protein was significantly lower compared to that of the control. Purification of the corresponding proteins by ion exchange chromatography indicates that several isoforms of peroxidase occurred in both control and salicylic acid-treated samples. The activities of the extracellular peroxidases secreted by the salicylic acid-treated roots responded differently to calcium and lectins compared with those from untreated roots. Taken together, our data suggest that salicylic acid changes the isoforms of peroxidase secreted by wounded wheat roots.

  1. Synthesis, characterization and adsorption properties of diethylenetriamine-modified hypercrosslinked resins for efficient removal of salicylic acid from aqueous solution.

    PubMed

    Huang, Jianhan; Jin, Xiaoying; Mao, Jinglin; Yuan, Bin; Deng, Rujie; Deng, Shuguang

    2012-05-30

    We report an effective approach for tailoring the pore textural properties and surface polarity of a hypercrosslinked resin to enhance its adsorption capacity and selectivity for removing salicylic acid from aqueous solution. Four hypercrosslinked resins were synthesized by controlling the reaction time of the self Friedel-Crafts reaction of chloromethylated polystyrene-co-divinylbenzene, and then modified with diethylenetriamine to adjust their surface polarity. The resins were characterized with N(2) adsorption for pore textural properties, Fourier transform infrared spectroscopy (FT-IR) for surface functional groups, chemical analysis for residual chlorine content and weak basic exchange capacity. Adsorption equilibrium, kinetics and breakthrough performance were determined for the removal of salicylic acid from aqueous solution on a selected resin HJ-M01. The equilibrium adsorption capacity of salicylic acid on HJ-M01 is significantly higher than that on its precursor HJ-11 and a few commercial adsorbents including AB-8, XAD-4 and XAD-7. The dynamic adsorption capacity of salicylic acid on HJ-M01 was found to be 456.4 mg/L at a feed concentration of 1000 mg/L and 294 K. The used resin could be fully regenerated with 1% sodium hydroxide solution. The hypercrosslinked resins being developed were promising alternatives to commercial adsorbents for removing salicylic acid and other volatile organic compounds (VOCs) from aqueous solution.

  2. Removal of salicylic acid on perovskite-type oxide LaFeO3 catalyst in catalytic wet air oxidation process.

    PubMed

    Yang, Min; Xu, Aihua; Du, Hongzhang; Sun, Chenglin; Li, Can

    2007-01-02

    It has been found that salicylic acid can be removal effectively at the lower temperature of 140 degrees C on perovskite-type oxide LaFeO3 catalyst in the catalytic wet air oxidation (CWAO) process. Under the same condition, the activities for the CWAO of phenol, benzoic acid and sulfonic salicylic acid have been also investigated. The results indicated that, with compared to the very poor activities for phenol and benzoic acid, the activities for salicylic acid and sulfonic salicylic acid were very high, which are attributed to their same intramolecular H-bonding structures. With the role of hard acidity of intramolecular H-bonding, salicylic acid and sulfonic salicylic acid can be adsorbed effectively on the basic center of LaFeO3 catalyst and are easy to take place the total oxidation reaction. However, at temperatures higher than 140 degrees C, the intramolecular H-bonding structure of salicylic acid was destroyed and the activities at 160 and 180 degrees C decreased greatly, which confirms further the key role of intramolecular H-bonding in the CWAO. Moreover, the LaFeO3 catalyst also indicated a superior stability of activity and structure in CWAO of salicylic acid.

  3. Batch salicylic acid nitration by nitric acid/acetic acid mixture under isothermal, isoperibolic and adiabatic conditions.

    PubMed

    Andreozzi, R; Canterino, M; Caprio, V; Di Somma, I; Sanchirico, R

    2006-12-01

    Runaway phenomena and thermal explosions can originate during the nitration of salicylic acid by means of a nitric acid/acetic acid mixture when the thermal control is lost, mainly as a result of the formation and thermal decomposition of picric acid. The prediction of the behaviour of this system is thus of great importance in view of possible industrial applications and the need to avoid the occurrence of unwanted dangerous events. During a previous investigation a model was developed to simulate its behaviour when the starting concentration of the substrate is too low, thus, preventing the precipitation of poor soluble intermediates. In this work this model is extended to deal with more concentrated systems even in case of a solid phase separating during the process. To this purpose the previously assessed dependence of the solubility of 3-nitro and 5-nitrosalicylic acids upon temperature and nitric acid concentration is included in the model. It is assumed that when 3-nitro and 5-nitrosalicylic acids are partially suspended in the reacting medium a kinetic regime of "dissolution with reaction" is established; that is, the redissolution of these species is a fast process compared to the successive nitration to give dinitroderivatives. Good results are obtained in the comparison of the experimental data with those calculated both in isoperibolic and adiabatic conditions when the revised model is used.

  4. Abscisic acid induces biosynthesis of bisbibenzyls and tolerance to UV-C in the liverwort Marchantia polymorpha.

    PubMed

    Kageyama, Akito; Ishizaki, Kimitsune; Kohchi, Takayuki; Matsuura, Hideyuki; Takahashi, Kosaku

    2015-09-01

    Environmental stresses are effective triggers for the biosynthesis of various secondary metabolites in plants, and phytohormones such as jasmonic acid and abscisic acid are known to mediate such responses in flowering plants. However, the detailed mechanism underlying the regulation of secondary metabolism in bryophytes remains unclear. In this study, the induction mechanism of secondary metabolites in the model liverwort Marchantia polymorpha was investigated. Abscisic acid (ABA) and ultraviolet irradiation (UV-C) were found to induce the biosynthesis of isoriccardin C, marchantin C, and riccardin F, which are categorized as bisbibenzyls, characteristic metabolites of liverworts. UV-C led to the significant accumulation of ABA. Overexpression of MpABI1, which encodes protein phosphatase 2C (PP2C) as a negative regulator of ABA signaling, suppressed accumulation of bisbibenzyls in response to ABA and UV-C irradiation and conferred susceptibility to UV-C irradiation. These data show that ABA plays a significant role in the induction of bisbibenzyl biosynthesis, which might confer tolerance against UV-C irradiation in M. polymorpha.

  5. Starch and Sucrose Synthesis in Phaseolus vulgaris as Affected by Light, CO2, and Abscisic Acid 1

    PubMed Central

    Sharkey, Thomas D.; Berry, Joseph A.; Raschke, Klaus

    1985-01-01

    Phaseolus vulgaris L. leaves were subjected to various light, CO2, and O2 levels and abscisic acid, then given a 10 minute pulse of 14CO2 followed by a 5 minute chase with unlabeled CO2. After the chase period, very little label remained in the ionic fractions (presumed to be mostly carbon reduction and carbon oxidation cycle intermediates and amino acids) except at low CO2 partial pressure. Most label was found in the neutral, alcohol soluble fraction (presumed sucrose) or in the insoluble fraction digestable by amyloglucosidase. Sucrose formation was linearly related to assimilation rate (slope = 0.35). Starch formation increased linearly with assimilation rate (slope = 0.56) but did not occur if the assimilation rate was below 4 micromoles per square meter per second. Neither abscisic acid, nor high CO2 in combination with low O2 (thought to disrupt control of carbon metabolism) caused significant perturbations of the sucrose/starch formation ratio. These studies indicate that the pathways for starch and sucrose synthesis both are controlled by the rate of net CO2 assimilation, with sucrose the preferred product at very low assimilation rates. PMID:16664108

  6. Efficacy of salicylic acid in the treatment of digital dermatitis in dairy cattle.

    PubMed

    Schultz, N; Capion, N

    2013-11-01

    Digital dermatitis (DD) is one of the most important causes of lameness in dairy cattle worldwide. The objective of this study was to evaluate the efficacy of salicylic acid in the treatment of the disease. A total of 201 DD lesions from 173 cows from four commercial dairy herds were evaluated at day 0 during routine hoof trimming and were allocated into two groups, namely, a control group given chlortetracycline spray, and a treatment group given 10 g of salicylic acid powder applied topically within a bandage. Pain, lesion size and clinical appearance (scored M0 to M4) were evaluated on days 3, 14 and 34 post-treatment. A change to M0 was defined as healing, while changes of M2 or M4 to M1 or M3 were classified as clinical improvements. Healing rates did not differ significantly between treatment groups at days 3 and 14. By day 34 the healing rate was fivefold better (P=0.01) for the treatment vs. the control group, with healing rates of 13.6% and 3.1%, respectively. By day 3, the rate of improvement was 2.5-fold better (P=0.02) for the controls. By day 34 the overall positive effect (i.e. healing and improvement) was 1.75-fold better (P=0.05) for the treatment group. Lesions from the control group were 2.2 times more likely (P=0.09) to have a pain score equal to 2 by day 14. The proportion of lesions getting smaller by days 14 and 34 was 2.5 times higher (P<0.08) for the treatment vs. the control group. The findings suggest salicylic acid should be considered as an alternative to chlortetracycline for the treatment of DD as it appears more efficacious and would assist in reducing antibiotic use.

  7. The Basic Leucine Zipper Transcription Factor ABSCISIC ACID RESPONSE ELEMENT-BINDING FACTOR2 Is an Important Transcriptional Regulator of Abscisic Acid-Dependent Grape Berry Ripening Processes1[W][OPEN

    PubMed Central

    Nicolas, Philippe; Lecourieux, David; Kappel, Christian; Cluzet, Stéphanie; Cramer, Grant; Delrot, Serge; Lecourieux, Fatma

    2014-01-01

    In grape (Vitis vinifera), abscisic acid (ABA) accumulates during fruit ripening and is thought to play a pivotal role in this process, but the molecular basis of this control is poorly understood. This work characterizes ABSCISIC ACID RESPONSE ELEMENT-BINDING FACTOR2 (VvABF2), a grape basic leucine zipper transcription factor belonging to a phylogenetic subgroup previously shown to be involved in ABA and abiotic stress signaling in other plant species. VvABF2 transcripts mainly accumulated in the berry, from the onset of ripening to the harvesting stage, and were up-regulated by ABA. Microarray analysis of transgenic grape cells overexpressing VvABF2 showed that this transcription factor up-regulates and/or modifies existing networks related to ABA responses. In addition, grape cells overexpressing VvABF2 exhibited enhanced responses to ABA treatment compared with control cells. Among the VvABF2-mediated responses highlighted in this study, the synthesis of phenolic compounds and cell wall softening were the most strongly affected. VvABF2 overexpression strongly increased the accumulation of stilbenes that play a role in plant defense and human health (resveratrol and piceid). In addition, the firmness of fruits from tomato (Solanum lycopersicum) plants overexpressing VvABF2 was strongly reduced. These data indicate that VvABF2 is an important transcriptional regulator of ABA-dependent grape berry ripening. PMID:24276949

  8. Transcriptome analysis reveals specific modulation of abscisic acid signaling by ROP10 small GTPase in Arabidopsis.

    PubMed

    Xin, Zeyu; Zhao, Yihong; Zheng, Zhi-Liang

    2005-11-01

    Abscisic acid (ABA) is a hormone that modulates a variety of agronomically important growth and developmental processes and various stresses responses, but its signal transduction pathways remain poorly understood. ROP10, a member of ROP small GTPases in Arabidopsis (Arabidopsis thaliana), is a plasma membrane-associated protein specifically involved in negative regulation of ABA responses. To dissect the ROP10-mediated ABA signaling, we carried out transcriptome analysis using the Arabidopsis full-genome chip. Our analysis revealed a total of 262 and 125 genes that were, respectively, up- and down-regulated (> or =2-fold cutoff) by 1 mum ABA in wild type (Wassilewskija [Ws]); 42 up-regulated and 38 down-regulated genes have not been identified in other studies. Consistent with the nonpleiotropic phenotypes of rop10-1, only three genes were altered in rop10-1 in the absence of ABA treatment. In response to 1 microm ABA, 341 and 127 genes were, respectively, activated and repressed in rop10-1. Interestingly, a particular subset of 21 genes that were not altered by 1 microm ABA in Ws but only activated in rop10-1 was identified. Reverse transcription-polymerase chain reaction analysis revealed the existence of three distinct categories of ABA dose-response patterns. One novel category is characterized by their ABA unresponsiveness in Ws and activation in rop10-1 at 1 microm but not 10 and 100 microm of ABA. This indicates that ROP10 gates the expression of genes that are specific to low concentrations of ABA. Furthermore, almost all of these 21 genes are known to be highly induced by various biotic and abiotic stresses. Consequently, we found that rop10-1 enhanced the sensitivity of seed germination inhibition to mannitol and sodium chloride. Our results suggest that ROP10 negatively regulates ABA responses by specifically and differentially modulating the ABA sensitivity of a subset of genes including protein kinases and zinc-finger family proteins.

  9. Treatment of solar keratoses with a 5-fluorouracil and salicylic acid varnish.

    PubMed

    Goncalves, J C

    1975-01-01

    In an attempt to avoid the side-effects of treating solar keratoses with 5% 5-fluorouracil (5-FU) ointment, a new pharmacological varnish containing 5% 5-FU and 5-10% salicylic acid to collodium was tried. Twenty patients with such lesions were treated. A drop of the varnish was applied on each lesion every 3 weeks. Only one to five applications on facial lesions were necessary to obtain apparent cure in all patients. Lesions reappeared in four patients, but were cured after a second and similar treatment. The keratoses of the hands were more resistant and needed seven applications in one patient and nine in the other.

  10. One-stop genomic DNA extraction by salicylic acid-coated magnetic nanoparticles.

    PubMed

    Zhou, Zhongwu; Kadam, Ulhas S; Irudayaraj, Joseph

    2013-11-15

    Salicylic acid-coated magnetic nanoparticles were prepared via a modified one-step synthesis and used for a one-stop extraction of genomic DNA from mammalian cells. The synthesized magnetic particles were used for magnetic separation of cells from the media by nonspecific binding of the particles as well as extraction of genomic DNA from the lysate. The quantity and quality were confirmed by agarose gel electrophoresis and polymerase chain reaction. The entire process of extraction and isolation can be completed within 30 min. Compared with traditional methods based on centrifugation and filtration, the established method is fast, simple, reliable, and environmentally friendly.

  11. Starch and sucrose synthesis in Phaseolus vulgaris as affected by light, CO/sub 2/, and abscisic acid

    SciTech Connect

    Sharkey, T.D.; Berry, J.A.; Raschke, K.

    1985-03-01

    Phaseolus vulgaris L. leaves were subjected to various light, CO/sub 2/, and O/sub 2/ levels and abscisic acid, then given a 10 minute pulse of /sup 14/CO/sub 2/ followed by a 5 minute chase with unlabeled CO/sub 2/. After the chase period, very little label remained in the ionic fractions except at low CO/sub 2/ partial pressure. Most label was found in the neutral, alcohol soluble fraction or in the insoluble fraction digestable by amyloglucosidase. Sucrose formation was linearly related to assimilation rate. Starch formation increased linearly with assimilation rate, but did not occur if the assimilation rate was below 4 micromoles per square meter per second. Neither abscisic acid, nor high CO/sub 2/ in combination with low O/sub 2/ caused significant perturbations of the sucrose/starch formation ratio. These studies indicate that the pathways for starch and sucrose synthesis both are controlled by the rate of net CO/sub 2/ assimilation, with sucrose the preferred product at very low assimilation rates.

  12. Influence of abscisic acid on growth, biomass and lipid yield of Scenedesmus quadricauda under nitrogen starved condition.

    PubMed

    Sulochana, Sujitha Balakrishnan; Arumugam, Muthu

    2016-08-01

    Scenedesmus quadricauda, accumulated more lipid but with a drastic reduction in biomass yield during nitrogen starvation. Abscisic acid (ABA) being a stress responsible hormone, its effect on growth and biomass with sustainable lipid yield during nitrogen depletion was studied. The result revealed that the ABA level shoots up at 24h (27.21pmol/L) during the onset of nitrogen starvation followed by a sharp decline. The external supplemented ABA showed a positive effect on growth pattern (38×10(6)cells/ml) at a lower concentration. The dry biomass yield is also increasing up to 2.1 fold compared to nitrogen deficient S. quadricauda. The lipid content sustains in 1 and 2μM concentration of ABA under nitrogen-deficient condition. The fatty acid composition of ABA treated S. quadricauda cultures with respect to nitrogen-starved cells showed 11.17% increment in saturated fatty acid content, the desired lipid composition for biofuel application.

  13. Comparative effects of auxin and abscisic acid on growth, hydrogen ion efflux and gravitropism in primary roots of maize

    NASA Technical Reports Server (NTRS)

    Evans, M. L.; Mulkey, T. J.

    1984-01-01

    In order to test the idea that auxin action on root growth may be mediated by H(+) movement, the correlation of auxin action on growth and H(+) movement in roots was examined along with changes in H(+) efflux patterns associated with the asymmetric growth which occurs during gravitropism. The effects of indoleacetic acid (IAA) and abscisic acid (AbA) on growth, H(+) secretion, and gravitropism in roots were compared. Results show a close correlation existent between H(+) efflux and growth in maize roots. In intact roots there is strong H(+) efflux from the elongation zone. Growth-promoting concentrations of IAA stimulate H(+) efflux. During gravitropism the H(+) efflux from the elongation zone becomes asymmetric; the evidence indicates that auxin redistribution contributes to the development of acid efflux asymmetry. That AbA stimulates root growth is reflected in its ability to stimulate H(+) efflux from apical root segments.

  14. Salicylic acid (SA) bioaccessibility from SA-based poly(anhydride-ester).

    PubMed

    Rogers, Michael A; Yan, Yim-Fan; Ben-Elazar, Karen; Lan, Yaqi; Faig, Jonathan; Smith, Kervin; Uhrich, Kathryn E

    2014-09-08

    The bioaccessibility of salicylic acid (SA) can be effectively modified by incorporating the pharmacological compound directly into polymers such as poly(anhydride-esters). After simulated digestion conditions, the bioaccessibility of SA was observed to be statistically different (p < 0.0001) in each sample: 55.5 ± 2.0% for free SA, 31.2 ± 2.4% the SA-diglycolic acid polymer precursor (SADG), and 21.2 ± 3.1% for SADG-P (polymer). The release rates followed a zero-order release rate that was dependent on several factors, including (1) solubilization rate, (2) macroscopic erosion of the powdered polymer, (3) hydrolytic cleavage of the anhydride bonds, and (4) subsequent hydrolysis of the polymer precursor (SADG) to SA and diglycolic acid.

  15. Derivatives of Salicylic Acid as Inhibitors of YopH in Yersinia pestis

    PubMed Central

    Huang, Zunnan; He, Yantao; Zhang, Xian; Gunawan, Andrea; Wu, Li; Zhang, Zhong-Yin; Wong, Chung F.

    2010-01-01

    Yersinia pestis causes diseases ranging from gastrointestinal syndromes to bubonic plague and could be misused as a biological weapon. As its protein tyrosine phosphatase YopH has already been demonstrated as a potential drug target, we have developed two series of forty salicylic acid derivatives and found sixteen to have micromolar inhibitory activity. We designed these ligands to have two chemical moieties connected by a flexible hydrocarbon linker to target two pockets in the active site of the protein to achieve binding affinity and selectivity. One moiety possessed the salicylic acid core intending to target the phosphotyrosine-binding pocket. The other moiety contained different chemical fragments meant to target a nearby secondary pocket. The two series of compounds differed by having hydrocarbon linkers with different lengths. Before experimental co-crystal structures are available, we have performed molecular docking to predict how these compounds might bind to the protein and to generate structural models for performing binding affinity calculation to aid future optimization of these series of compounds. PMID:20560978

  16. Synthesis and cofluorescence of Eu(Y) complexes with salicylic acid and o-phenanthroline

    NASA Astrophysics Data System (ADS)

    Xu, Cun-Jin; Xie, Fei; Guo, Xing-Zhong; Yang, Hui

    2005-07-01

    A series of dinuclear complexes of salicylic acid (HSal) and o-phenanthroline (Phen) with different molar ratios of Eu 3+ to Y 3+ have been synthesized. Their compositions are Eu xY 1-x (Sal) 3(Phen) ( x = 0 ˜ 1). Their UV spectra, IR spectra, and fluorescence spectra were studied. The UV spectra of the complexes reflect essentially absorption of the ligands for the fact that no obvious change of wavelength and band shape is found between the spectra of the complexes and that of the ligands except slight red shift. The IR absorption spectra indicate that salicylic acid is coordinated to the rare earth ions and chemical bonds are formed between rare earth ions and nitrogen atoms of o-phenanthroline. The fluorescence spectra of the complexes indicate that the fluorescence emission intensity of europium ion was enhanced by the addition of Y 3+, which is referred to as cofluorescence. These facts show that not only the ligands but also the yttrium complex can transfer the absorbed energy to Eu 3+ ion in the complexes. Formation of polynuclear complexes appears to be responsible for cofluorescence.

  17. A novel methyltransferase from the intracellular pathogen Plasmodiophora brassicae methylates salicylic acid.

    PubMed

    Ludwig-Müller, Jutta; Jülke, Sabine; Geiß, Kathleen; Richter, Franziska; Mithöfer, Axel; Šola, Ivana; Rusak, Gordana; Keenan, Sandi; Bulman, Simon

    2015-05-01

    The obligate biotrophic pathogen Plasmodiophora brassicae causes clubroot disease in Arabidopsis thaliana, which is characterized by large root galls. Salicylic acid (SA) production is a defence response in plants, and its methyl ester is involved in systemic signalling. Plasmodiophora brassicae seems to suppress plant defence reactions, but information on how this is achieved is scarce. Here, we profile the changes in SA metabolism during Arabidopsis clubroot disease. The accumulation of SA and the emission of methylated SA (methyl salicylate, MeSA) were observed in P. brassicae-infected Arabidopsis 28 days after inoculation. There is evidence that MeSA is transported from infected roots to the upper plant. Analysis of the mutant Atbsmt1, deficient in the methylation of SA, indicated that the Arabidopsis SA methyltransferase was not responsible for alterations in clubroot symptoms. We found that P. brassicae possesses a methyltransferase (PbBSMT) with homology to plant methyltransferases. The PbBSMT gene is maximally transcribed when SA production is highest. By heterologous expression and enzymatic analyses, we showed that PbBSMT can methylate SA, benzoic and anthranilic acids.

  18. Locally delivered salicylic acid from a poly(anhydride-ester): impact on diabetic bone regeneration.

    PubMed

    Wada, Keisuke; Yu, Weiling; Elazizi, Mohamad; Barakat, Sandrine; Ouimet, Michelle A; Rosario-Meléndez, Roselin; Fiorellini, Joseph P; Graves, Dana T; Uhrich, Kathryn E

    2013-10-10

    Diabetes mellitus (DM) involves metabolic changes that can impair bone repair, including a prolonged inflammatory response. A salicylic acid-based poly(anhydride-ester) (SA-PAE) provides controlled and sustained release of salicylic acid (SA) that locally resolves inflammation. This study investigates the effect of polymer-controlled SA release on bone regeneration in diabetic rats where enhanced inflammation is expected. Fifty-six Sprague-Dawley rats were randomly assigned to two groups: diabetic group induced by streptozotocin (STZ) injection or normoglycemic controls injected with citrate buffer alone. Three weeks after hyperglycemia development or vehicle injection, 5mm critical sized defects were created at the rat mandibular angle and treated with SA-PAE/bone graft mixture or bone graft alone. Rats were euthanized 4 and 12weeks after surgery, then bone fill percentage in the defect region was assessed by micro-computed tomography (CT) and histomorphometry. It was observed that bone fill increased significantly at 4 and 12weeks in SA-PAE/bone graft-treated diabetic rats compared to diabetic rats receiving bone graft alone. Accelerated bone formation in normoglycemic rats caused by SA-PAE/bone graft treatment was observed at 4weeks but not at 12weeks. This study shows that treatment with SA-PAE enhances bone regeneration in diabetic rats and accelerates bone regeneration in normoglycemic animals.

  19. Effect of ca2+ to salicylic acid release in pectin based controlled drug delivery system

    NASA Astrophysics Data System (ADS)

    Kistriyani, L.; Wirawan, S. K.; Sediawan, W. B.

    2016-01-01

    Wastes from orange peel are potentially be utilized to produce pectin, which are currently an import commodity. Pectin can be used in making edible film. Edible films are potentially used as a drug delivery system membrane after a tooth extraction. Drug which is used in the drug delivery system is salicylic acid. It is an antiseptic. In order to control the drug release rate, crosslinking process is added in the manufacturing of membrane with CaCl2.2H2O as crosslinker. Pectin was diluted in water and mixed with a plasticizer and CaCl2.2H2O solution at 66°C to make edible film. Then the mixture was dried in an oven at 50 °C. After edible film was formed, it was coated using plasticizer and CaCl2.2H2O solution with various concentration 0, 0.015, 0.03 and 0.05g/mL. This study showed that the more concentration of crosslinker added, the slower release of salicylic acid would be. This was indicated by the value of diffusivites were getting smaller respectively. The addition of crosslinker also caused smaller gels swelling value,which made the membrane is mechanically stronger

  20. Fe3O4/Salicylic acid nanoparticles behavior on chick CAM vasculature

    NASA Astrophysics Data System (ADS)

    Mihaiescu, Dan Eduard; Buteică, Alice Sandra; Neamţu, Johny; Istrati, Daniela; Mîndrilă, Ion

    2013-08-01

    A modified ferrite co-precipitation synthesis was used to obtain core-shell Fe3O4/salicylic acid magnetic nanoparticles (Sa-MNP) with well-dispersed aqueous solution properties. The newly developed iron oxide nanoparticles properties were investigated with X-ray diffraction, Fourier transform infrared spectrometry, transmission electron microscopy, and laser light scattering for their characteristic establishment. The resulting Sa-MNPs have spherical morphology, homogenous size distribution around 60 nm (35 nm FWHM), and a 67 mV Zeta potential value (15.5 mV STDV). In vivo biocompatibility and intravascular behavior of the 60 nm diameter size range synthesized nanoparticles were evaluated on chick chorioallantoic membrane model. The results show a reversible and good controlled intravascular accumulation under static magnetic field, a low risk of embolisation with nanoparticle aggregates detached from venous intravascular nanoblocked areas, a persistent blocking of the arterioles and dependent capillaries network, a good circulating life time and biocompatibility. The beneficial effects of salicylic acid (SA) and in vivo demonstrated capacity of Sa-MNPs to cutoff regional vascular supply under static magnetic field control suggest a possible biomedical application of these MNPs in targeted cancer therapy through magnetic controlled blood flow nanoblocking mechanism.

  1. Salicylic acid enhances antioxidant system in Brassica juncea grown under different levels of manganese.

    PubMed

    Parashar, Akshaya; Yusuf, Mohammad; Fariduddin, Qazi; Ahmad, Aqil

    2014-09-01

    The aim was to explore the responses of varied doses of manganese in mustard plants and also to test the proposition that salicylic acid induced up-regulation of antioxidant system which protect photosynthetic apparatus. Seeds were sown in pots and allowed to germinate under natural environmental conditions. At 10 days stage, soils in the pots were enriched with different levels (0, 3, 6, or 9 mM) of Mn for three days and allowed to grow till 30 day stage. At 31st day, foliage of plants was sprayed with 10 μM of salicylic acid (SA) and then allowed to grow till 45 days. Then plants were harvested to assess various growth, leaf gas exchange traits and biochemical parameters. Mn-treated plants had diminished growth, water relations and photosynthetic attributes along with carbonic anhydrase activity whereas; the level of lipid peroxidation, electrolyte leakage, accumulation of H2O2 along with proline accumulation and antioxidant enzymes increased in a concentration dependent manner. Follow-up application of SA to the Mn-stressed plants improved growth, water relations and photosynthetic traits, accelerated the activity of antioxidant enzymes and also the accumulation of proline. SA mediated tolerance to Mn-stressed plants could have due to up-regulation of antioxidant enzymes and proline accumulation.

  2. Electrocatalytic oxidation of salicylic acid by a cobalt hydrotalcite-like compound modified Pt electrode.

    PubMed

    Gualandi, Isacco; Scavetta, Erika; Zappoli, Sergio; Tonelli, Domenica

    2011-03-15

    In this paper a study of the electrocatalytic oxidation of salicylic acid (SA) at a Pt electrode coated with a Co/Al hydrotalcite-like compound (Co/Al HTLC coated-Pt) film is presented. The voltammetric behaviour of the modified electrode in 0.1M NaOH shows two different redox couples: Co(II)/Co(III) and Co(III)/Co(IV). The electrocatalysis occurs at the same potential of the latter couple, showing that Co(IV) centers act as the oxidant. The CV investigation demonstrates that the process is controlled both by mass and charge transfer and that the Co(IV) centers involved in the oxidation are two for each SA molecule. The estimated value of the catalytic constant is 4×10(4) M(-1) s(-1). The determination of salicylic acid was performed both by DPV and chronoamperometry. The linearity ranges and the LOD values resulted 1×10(-5) to 5×10(-4), 5×10(-7) to 1×10(-4), 6×10(-6) and 2×10(-7) M, respectively. The Co/Al HTLC electrode has been used for SA determination in BAYER Aspirina® and the obtained results are consistent with an independent HPLC analysis.

  3. Solid phase extraction-spectrophotometric determination of salicylic acid using magnetic iron oxide nanoparticles as extractor.

    PubMed

    Parham, Hooshang; Rahbar, Nadereh

    2009-08-15

    This method shows a novel, fast and simple solid phase extraction-spectrophotometric procedure for preconcentration and determination of salicylic acid (SA) in blood serum using magnetic iron oxide nanoparticles (MIONs) as extractor. It is shown that the novel magnetic nano-adsorbent is quite efficient for fast adsorption of SA at 25 degrees C. Various parameters affecting the adsorption of SA on MIONs, such as pH of solution, type, volume and concentration of desorbing reagent and amount of adsorbent and matrix effects, have been investigated. The calibration graph for the determination of SA was linear in the range of 0.025-1.250microgmL(-1). The limit of detection (LOD) based on three times the standard deviation of the blank (3S(b)) was 5.5x10(-3)microgmL(-1) (n=10) for SA. The intra-day precision (R.S.D.) was below 10.1% and inter-day R.S.D. was less than 17.5%, while accuracy (relative error R.E.) was within +/-3.6 determined from quality control samples for salicylic acid (SA) which corresponded to requirement of the guidance of Food and Drug Administration (FDA). The preconcentration factor of 100 was achieved in this method. The proposed procedure has been successfully applied to the determination of SA in blood serum.

  4. Cytosolic and chloroplastic DHARs cooperate in oxidative stress-driven activation of the salicylic acid pathway.

    PubMed

    Rahantaniaina, Marie-Sylviane; Li, Shengchun; Chatel-Innocenti, Gilles; Tuzet, Andrée; Issakidis-Bourguet, Emmanuelle; Mhamdi, Amna; Noctor, Graham

    2017-04-05

    The complexity of plant antioxidative systems gives rise to many unresolved questions. One relates to the functional importance of dehydroascorbate reductases (DHARs) in interactions between ascorbate and glutathione. To investigate this issue, we produced a complete set of loss-of-function mutants for the three annotated Arabidopsis DHARs. The combined loss of DHAR1 and DHAR3 expression decreased extractable activity to very low levels but had little effect on phenotype or ascorbate and glutathione pools in standard conditions. An analysis of the subcellular localization of the DHARs in Arabidopsis lines stably transformed with GFP fusion proteins revealed that DHAR1 and DHAR2 are cytosolic while DHAR3 is chloroplastic, with no evidence for peroxisomal or mitochondrial localizations. When the mutations were introduced into an oxidative stress genetic background (cat2), the dhar1 dhar2 combination decreased glutathione oxidation and inhibited cat2-triggered induction of the salicylic acid pathway. These effects were reversed in cat2 dhar1 dhar2 dhar3 complemented with any of the three DHARs. The data suggest that (1) DHAR can be decreased to negligible levels without marked effects on ascorbate pools; (2) the cytosolic isoforms are particularly important in coupling intracellular H2O2 metabolism to glutathione oxidation; (3) DHAR-dependent glutathione oxidation influences redox-driven salicylic acid accumulation.

  5. PeaT1-induced systemic acquired resistance in tobacco follows salicylic acid-dependent pathway.

    PubMed

    Zhang, Wei; Yang, Xiufen; Qiu, Dewen; Guo, Lihua; Zeng, Hongmei; Mao, Jianjun; Gao, Qiufeng

    2011-04-01

    Systemic acquired resistance (SAR) is an inducible defense mechanism which plays a central role in protecting plants from pathogen attack. A new elicitor, PeaT1 from Alternaria tenuissima, was expressed in Escherichia coil and characterized with systemic acquired resistance to tobacco mosaic virus (TMV). PeaT1-treated plants exhibited enhanced systemic resistance with a significant reduction in number and size of TMV lesions on wild tobacco leaves as compared with control. The quantitative analysis of TMV CP gene expression with real-time quantitative PCR showed there was reduction in TMV virus concentration after PeaT1 treatment. Similarly, peroxidase (POD) activity and lignin increased significantly after PeaT1 treatment. The real-time quantitative PCR revealed that PeaT1 also induced the systemic accumulation of pathogenesis-related gene, PR-1a and PR-1b which are the markers of systemic acquired resistance (SAR), NPR1 gene for salicylic acid (SA) signal transduction pathway and PAL gene for SA synthesis. The accumulation of SA and the failure in development of similar level of resistance as in wild type tobacco plants in PeaT1 treated nahG transgenic tobacco plants indicated that PeaT1-induced resistance depended on SA accumulation. The present work suggested that the molecular mechanism of PeaT1 inducing disease resistance in tobacco was likely through the systemic acquired resistance pathway mediated by salicylic acid and the NPR1 gene.

  6. Salicylic acid differently impacts ethylene and polyamine synthesis in the glycophyte Solanum lycopersicum and the wild-related halophyte Solanum chilense exposed to mild salt stress.

    PubMed

    Gharbi, Emna; Martínez, Juan-Pablo; Benahmed, Hela; Fauconnier, Marie-Laure; Lutts, Stanley; Quinet, Muriel

    2016-10-01

    This study aimed to determine the effects of exogenous application of salicylic acid (SA) on the toxic effects of salt in relation to ethylene and polyamine synthesis, and to correlate these traits with the expression of genes involved in ethylene and polyamine metabolism in two tomato species differing in their sensitivity to salt stress, Solanum lycopersicum cv Ailsa Craig and its wild salt-resistant relative Solanum chilense. In S. chilense, treatment with 125 mM NaCl improved plant growth, increased production of ethylene, endogenous salicylic acid and spermine. The production was related to a modification of expression of genes involved in ethylene and polyamine metabolism. In contrast, salinity decreased plant growth in S. lycopersicum without affecting endogenous ethylene, salicylic or polyamine concentrations. Exogenous application of salicylic acid at 0.01 mM enhanced shoot growth in both species and affected ethylene and polyamine production in S. chilense. Concomitant application of NaCl and salicylic acid improved osmotic adjustment, thus suggesting that salt and SA may act in synergy on osmolyte synthesis. However, the beneficial impact of exogenous application of salicylic acid was mitigated by salt stress since NaCl impaired endogenous SA accumulation in the shoot and salicylic acid did not improve plant growth in salt-treated plants. Our results thus revealed that both species respond differently to salinity and that salicylic acid, ethylene and polyamine metabolisms are involved in salt resistance in S. chilense.

  7. Study of supramolecular frameworks having aliphatic dicarboxylic acids, N,N‧-bis(salicyl)ethylenediamine and N,N‧-bis(salicyl)butylenediamine

    NASA Astrophysics Data System (ADS)

    Goel, Nidhi; Kumar, Naresh

    2014-08-01

    The reaction of bases (L1 and L2) (where L1 = N,N‧-bis(salicyl)ethylenediamine, L2 = N,N‧-bis(salicyl)butylenediamine) with dicarboxylic acids [adipic acid (1,6-Hexanedioic acid, AA), pimelic acid (1,7-Heptanedioic acid, PA) and suberic acid (1,8-Octanedioic acid, SUA] yielded the corresponding six new ionic salts viz., [1/2L1H+ṡ1/2AA-ṡ1/2AA] (1), [2 × 1/2L1H+ṡPA2-ṡCHCl3] (2) [1/2L1H+ṡ1/2SUA-] (3), [1/2L2H+ṡ1/2AA-ṡ2CH3OH] (4), [1/2L2H+ṡ1/2PA-] (5) and [1/2L2H+ṡ1/2SUA-] (6), respectively. Theses salts were characterized by elemental analysis, FT-IR, NMR, X-ray crystallography, and theoretically by means of Gaussian 09. The X-ray crystallographic studies revealed that the proton transfer occurred from acid to base. It also demonstrated that different type of hydrogen bond interactions between cations and anions were responsible for the supramolecular frameworks. The optimized structures of these salts were calculated in terms of the density functional theory. The curve fitting analysis between experimental and simulated data of structural parameters was done, and found statistically close. The orientation of molecules was remained same in both the gas and solid phases. The thermal studies of these salts were investigated by TG-DTG.

  8. [The ABC of abscisic acid action in plant drought stress responses].

    PubMed

    Leung, Jeffrey; Valon, Christiane; Moreau, Bertrand; Boeglin, Martin; Lefoulon, Cécile; Joshi-Saha, Archana; Chérel, Isabelle

    2012-01-01

    The combined daily consumption of fresh water ranges from 200 to 700 liters per capita per day in most developed countries, with about 70% being used for agricultural needs. Unlike other resources such as the different forms of energy, water has no other alternatives. With the looming prospect of global water crisis, the recent laudable success in deciphering the early steps in the signal transduction of the "stress hormone" abscisic acid (ABA) has ignited hopes that crops can be engineered with the capacity to maintain productivity while requiring less water input. Although ABA was first discovered in plants, it has resurfaced in the human brain (and many other non-plant organisms : sea sponge, some parasites, hydra to name a few), suggesting that its existence may be widespread. In humans, more amazingly, ABA has shown anti-inflammatory and antiviral properties. Even its receptors and key signaling intermediates have homologs in the human genome suggesting that evolution has re-fashioned these same proteins into new functional contexts. Thus, learning about the molecular mechanisms of ABA in action using the more flexible plant model will be likely beneficial to other organisms, and especially in human diseases, which is topical in the medical circle. ABA can accumulate up to 10 to 30-fold in plants under drought stress relative to unstressed conditions. The built up of the hormone then triggers diverse adaptive pathways permitting plants to withstand temporary bouts of water shortage. One favorite experimental model to unravel ABA signaling mechanisms in all of its intimate detail is based on the hormone's ability to elicit stomatal closure - a rapid cellular response of land plants to limit water loss through transpiration. Each microscopic stoma, or pore, is contoured by two specialized kidney-shaped cells called the guard cells. Because land plants are protected by a waxy cuticle impermeable to gas exchange, the stomatal pores are thus the primary portals for

  9. Quality and antioxidant properties on sweet cherries as affected by preharvest salicylic and acetylsalicylic acids treatments.

    PubMed

    Giménez, María José; Valverde, Juan Miguel; Valero, Daniel; Guillén, Fabián; Martínez-Romero, Domingo; Serrano, María; Castillo, Salvador

    2014-10-01

    The effects of salicylic acid (SA) or acetylsalicylic acid (ASA) treatments during on-tree cherry growth and ripening on fruit quality attributes, especially those related with the content on bioactive compounds and antioxidant activity were analysed in this research. For this purpose, two sweet cherry cultivars, 'Sweet Heart' and 'Sweet Late', were used and SA or ASA treatments, at 0.5, 1.0 and 2.0mM concentrations, were applied at three key points of fruit development (pit hardening, initial colour changes and onset of ripening). These treatments increased fruit weight and ameliorated quality attributes at commercial harvest, and led to cherries with higher concentration in total phenolics and in total anthocyanins, as well as higher antioxidant activity, in both hydrophilic and lipophilic fractions. Thus, preharvest treatments with SA or ASA could be promising tools to improve sweet cherry quality and health beneficial effects for consumers.

  10. Cadmium Toxicity and Alleviating Effects of Exogenous Salicylic Acid in Iris hexagona.

    PubMed

    Han, Ying; Chen, Gang; Chen, Yahua; Shen, Zhenguo

    2015-12-01

    Cadmium (Cd) toxictity and possible role of salicylic acid (SA) in alleviating Cd-induced toxicity were investigated on ornamental hydrophyte Iris hexagona. Compared to the control, treatments with 100 and 500 µM Cd for 7 days significantly decreased dry weight, the contents of chlorophyll, photosynthetic parameters, and increased the content of thiobarbituric acid reactive substance. Pretreatment of the roots of I. hexagona seedlings with 1 µM SA before Cd exposure may increase dry weight, photosynthetic rate, activities of antioxidant enzymes, improve the cell ultrastructure and protect plants from Cd-induced oxidative stress damage. However, SA pretreatment had no significant effect on Cd concentrations in the leaves and roots. It is suggested that SA-induced Cd tolerances in I. hexagona are likely associated with increases in antioxidant enzyme activities and vacuolar compartmentation, rather than Cd uptake.

  11. Method for the extraction of the volatile compound salicylic acid from tobacco leaf material.

    PubMed

    Verberne, Marianne C; Brouwer, Nynke; Delbianco, Federica; Linthorst, Huub J M; Bol, John F; Verpoorte, Robert

    2002-01-01

    Salicylic acid (SA) is a signalling compound in plants which is able to induce systemic acquired resistance. In the analysis of SA in plant tissues, the extraction recovery is often very low and variable. This is mainly caused by sublimation of SA, especially during evaporation of organic solvents. Techniques have been designed in order to overcome this problem. In the first part of the extraction procedure, sublimation of SA was prevented by addition of 0.2 M sodium hydroxide. At a later stage of the extraction procedure, sublimation of SA during solvent evaporation was controlled by the addition of a small amount of HPLC eluent. In this way, recoveries in the range of 71-91% for free SA and 65-79% for acid-hydrolysed SA were obtained. Recoveries could be further optimised by the use of an internal standard to correct for volume changes after the addition of the HPLC eluent.

  12. Chitosan oligosaccharide induces resistance to Tobacco mosaic virus in Arabidopsis via the salicylic acid-mediated signalling pathway.

    PubMed

    Jia, Xiaochen; Meng, Qingshan; Zeng, Haihong; Wang, Wenxia; Yin, Heng

    2016-05-18

    Chitosan is one of the most abundant carbohydrate biopolymers in the world, and chitosan oligosaccharide (COS), which is prepared from chitosan, is a plant immunity regulator. The present study aimed to validate the effect of COS on inducing resistance to tobacco mosaic virus (TMV) in Arabidopsis and to investigate the potential defence-related signalling pathways involved. Optimal conditions for the induction of TMV resistance in Arabidopsis were COS pretreatment at 50 mg/L for 1 day prior to inoculation with TMV. Multilevel indices, including phenotype data, and TMV coat protein expression, revealed that COS induced TMV resistance in wild-type and jasmonic acid pathway- deficient (jar1) Arabidopsis plants, but not in salicylic acid pathway deficient (NahG) Arabidopsis plants. Quantitative-PCR and analysis of phytohormone levels confirmed that COS pretreatment enhanced the expression of the defence-related gene PR1, which is a marker of salicylic acid signalling pathway, and increased the amount of salicylic acid in WT and jar1, but not in NahG plants. Taken together, these results confirm that COS induces TMV resistance in Arabidopsis via activation of the salicylic acid signalling pathway.

  13. Chitosan oligosaccharide induces resistance to Tobacco mosaic virus in Arabidopsis via the salicylic acid-mediated signalling pathway

    PubMed Central

    Jia, Xiaochen; Meng, Qingshan; Zeng, Haihong; Wang, Wenxia; Yin, Heng

    2016-01-01

    Chitosan is one of the most abundant carbohydrate biopolymers in the world, and chitosan oligosaccharide (COS), which is prepared from chitosan, is a plant immunity regulator. The present study aimed to validate the effect of COS on inducing resistance to tobacco mosaic virus (TMV) in Arabidopsis and to investigate the potential defence-related signalling pathways involved. Optimal conditions for the induction of TMV resistance in Arabidopsis were COS pretreatment at 50 mg/L for 1 day prior to inoculation with TMV. Multilevel indices, including phenotype data, and TMV coat protein expression, revealed that COS induced TMV resistance in wild-type and jasmonic acid pathway- deficient (jar1) Arabidopsis plants, but not in salicylic acid pathway deficient (NahG) Arabidopsis plants. Quantitative-PCR and analysis of phytohormone levels confirmed that COS pretreatment enhanced the expression of the defence-related gene PR1, which is a marker of salicylic acid signalling pathway, and increased the amount of salicylic acid in WT and jar1, but not in NahG plants. Taken together, these results confirm that COS induces TMV resistance in Arabidopsis via activation of the salicylic acid signalling pathway. PMID:27189192

  14. The Arabidopsis pi4kIIIβ1β2 double mutant is salicylic acid-overaccumulating: a new example of salicylic acid influence on plant stature

    PubMed Central

    Janda, Martin; Šašek, Vladimír; Ruelland, Eric

    2014-01-01

    Growth is the best visible sign of plant comfort. If plants are under stress, a difference in growth with control conditions can indicate that something is going wrong (or better). Phytohormones such as auxin, cytokinins, brassinosteroids or giberellins, are important growth regulators and their role in plant growth was extensively studied. On the other hand the role of salicylic acid (SA), a phytohormone commonly connected with plant defense responses, in plant growth is under-rated. However, studies with SA-overaccumulating mutants directly showed an influence of SA on plant growth. Recently we characterized an Arabidopsis SA-overaccumulating mutant impaired in phosphatidylinositol-4-kinases (pi4kIIIβ1β2). This mutant is dwarf. The crossing with mutants impaired in SA signaling revealed that pi4kIIIβ1β2 stunted rosette is due to high SA, while the short root length is not. This brings into evidence that upper and lower parts of the plants, even though they may share common phenotypes, are differently regulated. PMID:25482755

  15. Novel derivatives of nitro-substituted salicylic acids: Synthesis, antimicrobial activity and cytotoxicity.

    PubMed

    Paraskevopoulos, Georgios; Krátký, Martin; Mandíková, Jana; Trejtnar, František; Stolaříková, Jiřina; Pávek, Petr; Besra, Gurdyal; Vinšová, Jarmila

    2015-11-15

    Inspired by the high antituberculous activity of novel nitro-substituted derivatives and based on promising predicted ADMET properties we have synthesized a series of 33 salicylanilides containing nitro-group in their salicylic part and evaluated them for their in vitro antimycobacterial, antimicrobial and antifungal activities. The presence of nitro-group in position 4 of the salicylic acid was found to be beneficial and the resulting molecules exhibited minimum inhibitory concentrations (MICs) ranging from 2 to 32 μM against Mycobacterium tuberculosis. The best activity was found for 2-hydroxy-4-nitro-N-[4-(trifluoromethyl)phenyl]benzamide (MIC=2 μM). 4-Nitrosalicylanilides were also found to be active against all Staphylococcus species tested while for MRSA strain 2-hydroxy-4-nitro-N-[4-(trifluoromethyl)phenyl]benzamide's MIC was 0.98 μM. None of the nitrosalicylanilides was active against Enterococcus sp. J 14365/08 and no considerable activity was found against Gram-negative bacteria or fungi. The hepatotoxicity of all nitrosalicylanilides was found to be in the range of their MICs for HepG2 cells.

  16. A Simple Purification of Indole-3-Acetic Acid and Abscisic Acid for GC-SIM-MS Analysis by Microfiltration of Aqueous Samples through Nylon

    PubMed Central

    Dunlap, James R.; Guinn, Gene

    1989-01-01

    A simple procedure was developed for the partial purification of plant tissue samples to be analyzed simultaneously for indole-3-acetic acid (IAA) and abscisic acid (ABA). The procedure relies on removal of contaminants by filtration through nylon and partitioning into dichloromethane. This procedure successfully purified both IAA and ABA from muskmelon, cotton, and broccoli tissue. Twenty individual samples can be purified and methylated in 8 h for analysis of free IAA and ABA with gas chromatography-selected ion monitoring-mass spectrometry. The use of microfiltration of aqueous samples through nylon offers new opportunities for improving the efficiency of existing sample purification procedures. PMID:16666735

  17. Pathway of salicylic acid biosynthesis in healthy and virus-inoculated tobacco

    SciTech Connect

    Yalpani, N.; Leon, J.; Lawton, M.A.; Raskin, I. )

    1993-10-01

    Salicylic acid (SA) is a likely endogenous regulator of localized and systemic disease resistance in plants. During the hypersensitive response of Nicotiana tabacum L. cv Xanthi-nc to tobacco mosaic virus (TMV), SA levels rise dramatically. We studied Sa biosynthesis in healthy and TMV-inoculated tobacco by monitoring the levels of SA and its likely precursors in extracts of leaves and cell suspensions. In TMV-inoculated leaves, stimulation of Sa accumulation is accompanied by a corresponding increase in the levels of benzoic acid. [sup 14]C-Tracer studies with cell suspensions and mock- or TMV-inoculated leaves indicate that the label moves from trans-cinnamic acid to SA via benzoic acid. In healthy and TMV-inoculated tobacco leaves, benzoic acid induced SA accumulation. o-Coumaric acid, which was previously reported as a possible precursor of SA in other species, did not increase SA levels in tobacco. In healthy tobacco tissue, the specific activity of newly formed SA was equal to that of the supplied [[sup 14]C] benzoic acid, whereas in TMV-inoculated leaves some isotope dilution was observed, presumably because of the increase in the pool of endogenous benzoic acid. We observed accumulation of pathogenesis-related-1 proteins and increased resistance to TMV in benzoic acid but no in 0-coumaric acid-treated tobacco leaves. This is consistent with benzoic acid being the immediate precursor of SA. We conclude that in healthy and virus-inoculated tobacco, SA is formed from cinnamic acid via benzoic acid. 27 refs., 7 figs., 1 tab.

  18. The qSD12 Underlying Gene Promotes Abscisic Acid Accumulation in Early Developing Seeds to Induce Primary Dormancy in Rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seeds acquire primary dormancy during their development and the phytohormone abscisic acid (ABA) is considered to play a role in inducing the dormancy. qSD12 is a major seed dormancy QTL identified from weedy rice. This research was conducted to identify qSD12 candidate genes, isolate the candidat...

  19. 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.

  20. 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

  1. First derivative spectrophotometric and high performance liquid chromatographic simultaneous determination of benzoic and salicylic acids in pharmaceutical preparations.

    PubMed

    Silva, B O

    2008-01-01

    Two methods are presented for the simultaneous determination of benzoic and salicylic acids in pharmaceutical preparations using first (1D) derivative spectrophotometry and high-performance liquid chromatography. Benzoic and salicylic acids were determined by measurement of first derivative amplitude at the zero crossing points 283 and 310 nm respectively. Methanolic solutions obeyed Beer's law in the concentration range of 20-60 and 10-30 microg/ml for benzoic and salicylic acids respectively. The HPLC method depends upon using a Vydac reversed-phase column at ambient temperature with a mobile phase consisting of 20:80 (ACN:H2O) at a flow rate 0.5 ml min(-1) Quantitation was achieved with UV detection of 230 nm at 0 min and 204 nm at 4 min based on peak area. For the two methods the regression line equations were derived with correlation coefficient better than 0.995. The two methods were successfully applied to the simultaneous determination of benzoic and salicylic acids in laboratory-prepared mixtures and in creams with good accuracy and precision. No significant differences were found between the results obtained both by the HPLC and derivative procedures.

  2. Effect of multiple washing in salicylic acid on the bacterial flora of the skin of processed broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to determine changes in the bacterial flora of the skin of processed broilers after each of five consecutive washings in solutions of the keratolytic agent, salicylic acid. Skin samples from commercially processed broiler carcasses were divided into 3 groups and washed in ...

  3. Changes in the bacterial flora of skin of processed broiler chickens washed in solutions of salicylic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in the number of bacteria recovered from the skin of processed broilers after each of five consecutive washings in salicylic acid (SA) solutions was examined. Skin samples from commercially processed broiler carcasses were divided into 3 groups and washed in distilled water (control), 10% S...

  4. Exogenous salicylic acid enhances the resistance of wheat seedlings to hessian fly (Diptera: Cecidomyiidae) infestation under heat stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress exerts significant impact on plant-parasite interactions. Phytohormones, such as salicylic acid (SA) play important roles in plant defense against parasite attacks. Here we studied the impact of a combination of heat stress and exogenous SA on wheat (Triticum aestivum L.) plant resistanc...

  5. Application of a radiometric method for evaluation of loss of salicylic acid during isolation from biologic material.

    PubMed

    Ostrowski, A

    1983-01-01

    A radiometric method for evaluation of loss of salicylic acid in the process of isolation from biologic material is described. According to this study the mean loss during the total process of isolation amounts to 33.59%, the specific values being 19.47% during protein precipitation, 10.68% during extraction, and 3.44% during evaporation of solvent.

  6. Characterisation of SalRAB a salicylic acid inducible positively regulated efflux system of Rhizobium leguminosarum bv viciae 3841.

    PubMed

    Tett, Adrian J; Karunakaran, Ramakrishnan; Poole, Philip S

    2014-01-01

    Salicylic acid is an important signalling molecule in plant-microbe defence and symbiosis. We analysed the transcriptional responses of the nitrogen fixing plant symbiont, Rhizobium leguminosarum bv viciae 3841 to salicylic acid. Two MFS-type multicomponent efflux systems were induced in response to salicylic acid, rmrAB and the hitherto undescribed system salRAB. Based on sequence similarity salA and salB encode a membrane fusion and inner membrane protein respectively. salAB are positively regulated by the LysR regulator SalR. Disruption of salA significantly increased the sensitivity of the mutant to salicylic acid, while disruption of rmrA did not. A salA/rmrA double mutation did not have increased sensitivity relative to the salA mutant. Pea plants nodulated by salA or rmrA strains did not have altered nodule number or nitrogen fixation rates, consistent with weak expression of salA in the rhizosphere and in nodule bacteria. However, BLAST analysis revealed seventeen putative efflux systems in Rlv3841 and several of these were highly differentially expressed during rhizosphere colonisation, host infection and bacteroid differentiation. This suggests they have an integral role in symbiosis with host plants.

  7. Salicylic acid and cysteine contribute to arbutin-induced alleviation of angular leaf spot disease development in cucumber.

    PubMed

    Kuźniak, Elżbieta; Wielanek, Marzena; Chwatko, Grażyna; Głowacki, Rafał; Libik-Konieczny, Marta; Piątek, Milena; Gajewska, Ewa; Skłodowska, Maria

    2015-06-01

    Arbutin induced suppression of angular leaf spot disease in cucumber resulting from lower populations of Pseudomonas syringae pv lachrymans in the infected tissues. This study provides insight into mechanisms that may potentially account for this effect. In the absence of the pathogen, exogenous arbutin-induced expression of PR1, the marker of salicylic acid signaling, increased the content of salicylic acid and modulated the cysteine pool. This suggested that arbutin promoted cucumber plants to a "primed" state. When challenged with the pathogen, the arbutin-treated plants showed strongly reduced infection symptoms 7 days after inoculation. At this time point, they were characterized by higher contents of free and protein-bound cysteine due to higher cysteine biosynthetic capacity related to increased activities of serine acetyltransferase and cysteine synthase when compared with plants infected without arbutin treatment. Moreover, in the arbutin-treated and infected plants the contents of free salicylic acid and its conjugates were also increased, partly owing to its biosynthesis via the phenylpropanoid pathway. We suggest that arbutin-induced abrogation of angular leaf spot disease in cucumber could be mediated by salicylic acid and cysteine-based signaling.

  8. Cross-talk between salicylic acid and NaCl-generated reactive oxygen species and nitric oxide in tomato during acclimation to high salinity.

    PubMed

    Gémes, Katalin; Poór, Péter; Horváth, Edit; Kolbert, Zsuzsanna; Szopkó, Dóra; Szepesi, Agnes; Tari, Irma

    2011-06-01

    Hydrogen peroxide (H₂O₂) and nitric oxide (NO) generated by salicylic acid (SA) are considered to be functional links of cross-tolerance to various stressors. SA-stimulated pre-adaptation state was beneficial in the acclimation to subsequent salt stress in tomato (Solanum lycopersicum cv. Rio Fuego). At the whole-plant level, SA-induced massive H₂O₂ accumulation only at high concentrations (10⁻³-10⁻² M), which later caused the death of plants. The excess accumulation of H₂O₂ as compared with plants exposed to 100 mM NaCl was not associated with salt stress response after SA pre-treatments. In the root tips, 10⁻³-10⁻² M SA triggered the production of reactive oxygen species (ROS) and NO with a concomitant decline in the cell viability. Sublethal concentrations of SA, however, decreased the effect of salt stress on ROS and NO production in the root apex. The attenuation of oxidative stress because of high salinity occurred not only in pre-adapted plants but also at cell level. When protoplasts prepared from control leaves were exposed to SA in the presence of 100 mM NaCl, the production of NO and ROS was much lower and the viability of the cells was higher than in salt-treated samples. This suggests that, the cross-talk of signalling pathways induced by SA and high salinity may occur at the level of ROS and NO production. Abscisic acid (ABA), polyamines and 1-aminocyclopropane-1-carboxylic acid, the compounds accumulating in pre-treated plants, enhanced the diphenylene iodonium-sensitive ROS and NO levels, but, in contrast to others, ABA and putrescine preserved the viability of protoplasts.

  9. Promoter analyses and transcriptional profiling of eggplant polyphenol oxidase 1 gene (SmePPO1) reveal differential response to exogenous methyl jasmonate and salicylic acid.

    PubMed

    Shetty, Santoshkumar M; Chandrashekar, Arun; Venkatesh, Yeldur P

    2012-05-01

    The transcriptional regulation of multigenic eggplant (Solanum melongena) polyphenol oxidase genes (SmePPO) is orchestrated by their corresponding promoters which mediate developmentally regulated expression in response to myriad biotic and abiotic factors. However, information on structural features of SmePPO promoters and modulation of their expression by plant defense signals are lacking. In the present study, SmePPOPROMOTERs were cloned by genome walking, and their transcription start sites (TSS) were determined by RLM-RACE. Extensive sequence analyses revealed the presence of evolutionarily conserved and over-represented putative cis-acting elements involved in light-regulated transcription, biosynthetic pathways (phenylpropanoid/flavonoid), hormone signaling (abscisic acid, gibberellic acid, jasmonate and salicylate), elicitor and stress responses (cold/dehydration responses), sugar metabolism and plant defense signaling (W-BOX/WRKY) that are common to SmePPOPROMOTER1 and 2. The TSS for SmePPO genes are located 9-15bp upstream of ATG with variable lengths of 5' untranslated regions. Transcriptional profiling of SmePPOs in eggplant seedlings has indicated differential response to methyl jasmonate (MeJA) or salicylic acid (SA) treatment. In planta, while MeJA elicited expression of all the six SmePPOs, SA was only able to induce the expression of SmePPO4-6. Interestingly, in dual treatment, SA considerably repressed the MeJA-induced expression of SmePPOs. Functional dissection of SmePPOPROMOTER1 by deletion analyses using Agrobacterium-mediated transient expression in tobacco leaves has shown that MeJA enhances the SmePPOPROMOTER1-β-glucuronidase (GUS) expression in vivo, while SA does not. Histochemical and quantitative GUS assays have also indicated the negative effect of SA on MeJA-induced expression of SmePPOPROMOTER1. By combining in silico analyses, transcriptional profiling and expression of SmePPOPROMOTER1-GUS fusions, the role of SA on the modulation

  10. Effects of salicylic-lactic acid conditioner on the shear bond strength of brackets and enamel surfaces.

    PubMed

    Chang, W-G; Lim, B-S; Yoon, T-H; Lee, Y-K; Kim, C-W

    2005-04-01

    The purpose of this study was to evaluate the effects of salicylic-lactic (SL) acid conditioner on the shear bond strength of brackets. Fluoride releasing (Light-bond) and non-fluoride releasing (Enlight) composite adhesives were used after conditioning with 0.22% salicylic + 9% lactic acid or 34% phosphoric acid. Composite adhesives were light cured with either a halogen light curing (HLC) unit for 30-50 s or a plasma arc curing (PAC) unit for 4 s. The shear bond strength was measured with an Instron. Failure modes of debonded brackets were identified based on adhesive remnants on the bracket and tooth. Salicylic-lactic acid conditioning was found to provide adequate shear bond strength. Groups conditioned with SL acid were debonded mainly at the enamel-resin interface and comparatively clean enamel surface after debonding was observed than those conditioned with phosphoric acid. Using confocal laser scanning microscopic examinations, it was found that demineralization patterns between SL acid and phosphoric acid conditioned groups were not different when the same adhesive was used. The SL acid conditioner did not reduce the demineralization. Light-bond adhesive showed less demineralization than Enlight adhesive. The PAC unit can be recommended as an alterative to the HLC unit because it significantly reduces the irradiation time.

  11. Structural Insights into Maize Viviparous14, a Key Enzyme in the Biosynthesis of the Phytohormone Abscisic Acid W

    SciTech Connect

    Messing, S.; Gabelli, S; Echeverria, I; Vogel, J; Guan, J; Tan, B; Klee, H; McCarty, D; Amzela, M

    2010-01-01

    The key regulatory step in the biosynthesis of abscisic acid (ABA), a hormone central to the regulation of several important processes in plants, is the oxidative cleavage of the 11,12 double bond of a 9-cis-epoxycarotenoid. The enzyme viviparous14 (VP14) performs this cleavage in maize (Zea mays), making it a target for the rational design of novel chemical agents and genetic modifications that improve plant behavior through the modulation of ABA levels. The structure of VP14, determined to 3.2-{angstrom} resolution, provides both insight into the determinants of regio- and stereospecificity of this enzyme and suggests a possible mechanism for oxidative cleavage. Furthermore, mutagenesis of the distantly related CCD1 of maize shows how the VP14 structure represents a template for all plant carotenoid cleavage dioxygenases (CCDs). In addition, the structure suggests how VP14 associates with the membrane as a way of gaining access to its membrane soluble substrate.

  12. Structural Insights into Maize Viviparous14, a Key Enzyme in the Biosynthesis of the Phytohormone Abscisic Acid

    SciTech Connect

    Messing, Simon A.J.; Gabelli, Sandra B.; Echeverria, Ignacia; Vogel, Jonathan T.; Guan, Jiahn Chou; Tan, Bao Cai; Klee, Harry J.; McCarty, Donald R.; Amzel, L. Mario

    2011-09-06

    The key regulatory step in the biosynthesis of abscisic acid (ABA), a hormone central to the regulation of several important processes in plants, is the oxidative cleavage of the 11,12 double bond of a 9-cis-epoxycarotenoid. The enzyme viviparous14 (VP14) performs this cleavage in maize (Zea mays), making it a target for the rational design of novel chemical agents and genetic modifications that improve plant behavior through the modulation of ABA levels. The structure of VP14, determined to 3.2-{angstrom} resolution, provides both insight into the determinants of regio- and stereospecificity of this enzyme and suggests a possible mechanism for oxidative cleavage. Furthermore, mutagenesis of the distantly related CCD1 of maize shows how the VP14 structure represents a template for all plant carotenoid cleavage dioxygenases (CCDs). In addition, the structure suggests how VP14 associates with the membrane as a way of gaining access to its membrane soluble substrate.

  13. Synthesis, structural characterization and effect on human granulocyte intracellular cAMP levels of abscisic acid analogs.

    PubMed

    Bellotti, Marta; Salis, Annalisa; Grozio, Alessia; Damonte, Gianluca; Vigliarolo, Tiziana; Galatini, Andrea; Zocchi, Elena; Benatti, Umberto; Millo, Enrico

    2015-01-01

    The phytohormone abscisic acid (ABA), in addition to regulating physiological functions in plants, is also produced and released by several mammalian cell types, including human granulocytes, where it stimulates innate immune functions via an increase of the intracellular cAMP concentration ([cAMP]i). We synthesized several ABA analogs and evaluated the structure-activity relationship, by the systematical modification of selected regions of these analogs. The resulting molecules were tested for their ability to inhibit the ABA-induced increase of [cAMP]i in human granulocytes. The analogs with modified configurations at C-2' and C-3' abrogated the ABA-induced increase of the [cAMP]i and also inhibited several pro-inflammatory effects induced by exogenous ABA on granulocytes and monocytes. Accordingly, these analogs could be suitable as novel putative anti-inflammatory compounds.

  14. Salt-Related MYB1 Coordinates Abscisic Acid Biosynthesis and Signaling during Salt Stress in Arabidopsis1

    PubMed Central

    Wang, Ting; Tohge, Takayuki; Ivakov, Alexander; Mueller-Roeber, Bernd; Fernie, Alisdair R.; Mutwil, Marek; Schippers, Jos H.M.; Persson, Staffan

    2015-01-01

    Abiotic stresses, such as salinity, cause global yield loss of all major crop plants. Factors and mechanisms that can aid in plant breeding for salt stress tolerance are therefore of great importance for food and feed production. Here, we identified a MYB-like transcription factor, Salt-Related MYB1 (SRM1), that negatively affects Arabidopsis (Arabidopsis thaliana) seed germination under saline conditions by regulating the levels of the stress hormone abscisic acid (ABA). Accordingly, several ABA biosynthesis and signaling genes act directly downstream of SRM1, including SALT TOLERANT1/NINE-CIS-EPOXYCAROTENOID DIOXYGENASE3, RESPONSIVE TO DESICCATION26, and Arabidopsis NAC DOMAIN CONTAINING PROTEIN19. Furthermore, SRM1 impacts vegetative growth and leaf shape. We show that SRM1 is an important transcriptional regulator that directly targets ABA biosynthesis and signaling-related genes and therefore may be regarded as an important regulator of ABA-mediated salt stress tolerance. PMID:26243618

  15. Optically Pure Abscisic Acid Analogs—Tools for Relating Germination Inhibition and Gene Expression in Wheat Embryos 1

    PubMed Central

    Walker-Simmons, M. K.; Anderberg, Robert J.; Rose, Patricia A.; Abrams, Suzanne R.

    1992-01-01

    We report an examination of the structural requirements of the abscisic acid (ABA) recognition response in wheat dormant seed embryos using optically pure isomers of ABA analogs. These compounds include permutations to the ABA structure with either an acetylene or a trans bond at C-4 C-5, and either a single or double bond at the C-2′ C-3′ double bond. (R)-ABA and the three isomers with the same configuration at C-1′ as natural ABA were found to be effective germination inhibitors. The biologically active ABA analogs exhibited differential effects on ABA-responsive gene expression. All the ABA analogs that inhibited germination induced two ABA-responsive genes, wheat group 3 lea and dhn (rab). However, (R)-ABA and (S)-dihydroABA were less effective in inducing the ABA-responsive gene Em within the time that embryonic germination was inhibited. ImagesFigure 3Figure 4 PMID:16668914

  16. A mathematical model of the interaction of abscisic acid, ethylene and methyl jasmonate on stomatal closure in plants

    PubMed Central

    Hernandez, Bryan Sapon

    2017-01-01

    Stomatal closure is affected by various stimuli such as light, atmospheric carbon dioxide concentration, humidity and phytohormones. Our research focuses on phytohormones, specifically: abscisic acid (ABA), ethylene (ET) and methyl jasmonate (MeJA) that are responsible for the regulation of several plant processes, especially in guard cell signalling. While several studies show that these three phytohormones cause stomatal closure in plants, only two studies are notable for establishing a mathematical model of guard cell signalling involving phytohormones. Those two studies employed Boolean modelling and mechanistic ordinary differential equations modelling. In this study, we propose a new mathematical model of guard cell transduction network for stomatal closure using continuous logical modelling framework. Results showed how the different components of the network function. Furthermore, the model verified the role of antioxidants in the closure mechanism, and the diminished closure level of stomata with combined ABA-ET stimulus. The analysis was extended to ABA-ET-MeJA crosstalk. PMID:28182683

  17. FIA functions as an early signal component of abscisic acid signal cascade in Vicia faba guard cells.

    PubMed

    Sugiyama, Yusuke; Uraji, Misugi; Watanabe-Sugimoto, Megumi; Okuma, Eiji; Munemasa, Shintaro; Shimoishi, Yasuaki; Nakamura, Yoshimasa; Mori, Izumi C; Iwai, Sumio; Murata, Yoshiyuki

    2012-02-01

    An abscisic acid (ABA)-insensitive Vicia faba mutant, fia (fava bean impaired in ABA-induced stomatal closure) had previously been isolated. In this study, it was investigated how FIA functions in ABA signalling in guard cells of Vicia faba. Unlike ABA, methyl jasmonate (MeJA), H(2)O(2), and nitric oxide (NO) induced stomatal closure in the fia mutant. ABA did not induce production of either reactive oxygen species or NO in the mutant. Moreover, ABA did not suppress inward-rectifying K(+) (K(in)) currents or activate ABA-activated protein kinase (AAPK) in mutant guard cells. These results suggest that FIA functions as an early signal component upstream of AAPK activation in ABA signalling but does not function in MeJA signalling in guard cells of Vicia faba.

  18. An Abscisic Acid-Activated and Calcium-Independent Protein Kinase from Guard Cells of Fava Bean.

    PubMed

    Li, J.; Assmann, S. M.

    1996-12-01

    Abscisic acid (ABA) regulation of stomatal aperture is known to involve both Ca2+-dependent and Ca2+-independent signal transduction pathways. Electrophysiological studies suggest that protein phosphorylation is involved in ABA action in guard cells. Using biochemical approaches, we identified an ABA-activated and Ca2+- independent protein kinase (AAPK) from guard cell protoplasts of fava bean. Autophosphorylation of AAPK was rapidly (~1 min) activated by ABA in a Ca2+- independent manner. ABA-activated autophosphorylation of AAPK occurred on serine but not on tyrosine residues and appeared to be guard cell specific. AAPK phosphorylated histone type III-S on serine and threonine residues, and its activity toward histone type III-S was markedly stimulated in ABA-treated guard cell protoplasts. Our results suggest that AAPK may play an important role in the Ca2+-independent ABA signaling pathways of guard cells.

  19. Inhibition of Abscisic Acid Biosynthesis in Cercospora rosicola by Inhibitors of Gibberellin Biosynthesis and Plant Growth Retardants

    PubMed Central

    Norman, Shirley M.; Poling, Stephen M.; Maier, Vincent P.; Orme, Edward D.

    1983-01-01

    The fungus Cercospora rosicola produces abscisic acid (ABA) as a secondary metabolite. We developed a convenient system using this fungus to determine the effects of compounds on the biosynthesis of ABA. Inasmuch as ABA and the gibberellins (GAs) both arise via the isoprenoid pathway, it was of interest to determine if inhibitors of GA biosynthesis affect ABA biosynthesis. All five putative inhibitors of GA biosynthesis tested inhibited ABA biosynthesis. Several plant growth retardants with poorly understood actions in plants were also tested; of these, six inhibited ABA biosynthesis to varying degrees and two had no effect. Effects of plant growth retardants on various branches of the isoprenoid biosynthetic pathway may help to explain some of the diverse and unexpected results reported for these compounds. Knowledge that certain inhibitors of GA biosynthesis also have the ability to inhibit ABA biosynthesis in C. rosicola indicates the need for further studies in plants on the mode of action of these compounds. PMID:16662775

  20. Sensitivity during the forced swim test is a key factor in evaluating the antidepressant effects of abscisic acid in mice.

    PubMed

    Qi, Cong-Cong; Shu, Yu-Mian; Chen, Fang-Han; Ding, Yu-Qiang; Zhou, Jiang-Ning

    2016-03-01

    Abscisic acid (ABA), a crucial phytohormone, is distributed in the brains of mammals and has been shown to have antidepressant effects in the chronic unpredictable mild stress test. The forced swim test (FST) is another animal model that can be used to assess antidepressant-like behavior in rodents. Here, we report that the antidepressant effects of ABA are associated with sensitivities to the FST in mice. Based on mean immobility in the 5-min forced swim pre-test, ICR mice were divided into short immobility mice (SIM) and long immobility mice (LIM) substrains. FST was carried out 8 days after drug administration. Learned helplessness, as shown by increased immobility, was only observed in SIM substrain and could be prevented by an 8-day ABA treatment. Our results show that ABA has antidepressant effects in SIM substrain and suggest that mice with learned helplessness might be more suitable for screening potential antidepressant drugs.

  1. Aspirin and salicylic acid decrease c-Myc expression in cancer cells: a potential role in chemoprevention.

    PubMed

    Ai, Guoqiang; Dachineni, Rakesh; Muley, Pratik; Tummala, Hemachand; Bhat, G Jayarama

    2016-02-01

    Epidemiological studies have demonstrated a significant correlation between regular aspirin use and reduced colon cancer incidence and mortality; however, the pathways by which it exerts its anti-cancer effects are still not fully explored. We hypothesized that aspirin's anti-cancer effect may occur through downregulation of c-Myc gene expression. Here, we demonstrate that aspirin and its primary metabolite, salicylic acid, decrease the c-Myc protein levels in human HCT-116 colon and in few other cancer cell lines. In total cell lysates, both drugs decreased the levels of c-Myc in a concentration-dependent fashion. Greater inhibition was observed in the nucleus than the cytoplasm, and immunofluorescence studies confirmed these observations. Pretreatment of cells with lactacystin, a proteasome inhibitor, partially prevented the downregulatory effect of both aspirin and salicylic acid, suggesting that 26S proteasomal pathway is involved. Both drugs failed to decrease exogenously expressed DDK-tagged c-Myc protein levels; however, under the same conditions, the endogenous c-Myc protein levels were downregulated. Northern blot analysis showed that both drugs caused a decrease in c-Myc mRNA levels in a concentration-dependent fashion. High-performance liquid chromatography (HPLC) analysis showed that aspirin taken up by cells was rapidly metabolized to salicylic acid, suggesting that aspirin's inhibitory effect on c-Myc may occur through formation of salicylic acid. Our result suggests that salicylic acid regulates c-Myc level at both transcriptional and post-transcription levels. Inhibition of c-Myc may represent an important pathway by which aspirin exerts its anti-cancer effect and decrease the occurrence of cancer in epithelial tissues.

  2. Fluorescence characteristics of 5-amino salicylic acid: An iodide recognition study

    NASA Astrophysics Data System (ADS)

    Arora, Priyanka; Suyal, Kanchan; Joshi, Neeraj K.; Joshi, Hem Chandra; Pant, Sanjay

    In this paper we report the effect of iodide on the fluorescence of 5-amino salicylic acid (5-ASA). In the absence of iodide, prominent blue green (BG) emission band at ˜465 nm (broad) is observed in aprotic solvents whereas violet (V) emission at ˜408 nm, blue green (BG) at ˜480 nm and green (G) at ˜500 nm are observed in case of protic solvents. On the addition of iodide ion (I-), the intensity of BG fluorescence is enhanced in case of aprotic solvents. On the other hand the G band is enhanced in protic solvents and decrease in the intensity of the V band is observed. The effect of hydrogen bonding as well as the interplay of neutral and ionic species is invoked to explain the observed results. The study projects the application of this system in iodide recognition in protic/aprotic environments.

  3. Regulation of water, salinity, and cold stress responses by salicylic acid.

    PubMed

    Miura, Kenji; Tada, Yasuomi

    2014-01-01

    Salicylic acid (SA) is a naturally occurring phenolic compound. SA plays an important role in the regulation of plant growth, development, ripening, and defense responses. The role of SA in the plant-pathogen relationship has been extensively investigated. In addition to defense responses, SA plays an important role in the response to abiotic stresses, including drought, low temperature, and salinity stresses. It has been suggested that SA has great agronomic potential to improve the stress tolerance of agriculturally important crops. However, the utility of SA is dependent on the concentration of the applied SA, the mode of application, and the state of the plants (e.g., developmental stage and acclimation). Generally, low concentrations of applied SA alleviate the sensitivity to abiotic stresses, and high concentrations of applied induce high levels of oxidative stress, leading to a decreased tolerance to abiotic stresses. In this article, the effects of SA on the water stress responses and regulation of stomatal closure are reviewed.

  4. Proteomic Analysis of Responsive Proteins Induced in Japanese Birch Plantlet Treated with Salicylic Acid

    PubMed Central

    Suzuki, Hiromu; Takashima, Yuya; Ishiguri, Futoshi; Yoshizawa, Nobuo; Yokota, Shinso

    2014-01-01

    The present study was performed to unravel the mechanisms of systemic acquired resistance (SAR) establishment and resistance signaling pathways against the canker-rot fungus (Inonotus obliquus strain IO-U1) infection in Japanese birch plantlet No.8. Modulation of protein-profile induced by salicylic acid (SA)-administration was analyzed, and SA-responsive proteins were identified. In total, 5 specifically expressed, 3 significantly increased, and 3 significantly decreased protein spots were identified using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and the sequence tag method. These proteins were malate dehydrogenase, succinate dehydrogenase, phosphoglycerate kinase, diaminopimalate decarboxylase, arginase, chorismate mutase, cyclophilin, aminopeptidase, and unknown function proteins. These proteins are considered to be involved in SAR-establishment mechanisms in the Japanese birch plantlet No 8. PMID:28250384

  5. Determination of hydroxyl radicals with salicylic acid in aqueous nitrate and nitrite solutions.

    PubMed

    Yang, Xi; Zhan, Man-jun; Kong, Ling-ren; Wang, Lian-sheng

    2004-01-01

    The qualitative and quantitative analyses of reactive oxygen species are essential to determine their steady-state concentration and related reaction mechanisms in environmental aquatic systems. In this study, salicylic acid was employed as an innovative molecular probe of hydroxyl radical(OH) generated in aqueous nitrate and nitrite solutions through photochemical reactions. Kinetic studies showed that the steady-state concentrations of OH in aqueous NO3- (10 mmol/L, pH = 5) and NO2- (10 mmol/L, pH = 5) solutions under ultraviolet irradiation were at a same magnitude, 10(-15) mol/L. Apparent quantum yields of OH at 313 nm were measured as 0.011 and 0.07 for NO3- and NO2- respectively, all comparable to the results of previous studies.

  6. 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.

  7. Combined patch containing salicylic acid and nicotinamide: role of drug interaction.

    PubMed

    Padula, Cristina; Ferretti, Chiara; Nicoli, Sara; Santi, Patrizia

    2010-12-01

    The aim of the present study was to formulate a combined patch containing salicylic (SA) acid and nicotinamide (NA), useful for the treatment of mild acne, and to verify their mutual effect on drug permeation and skin retention. The performance of the patch was tested in vitro in permeation experiments using pig ear skin as barrier. To better understand the data obtained from the film, permeation from solutions and isopropyl myristate/water partition coefficient were also determined. The results obtained in the present work suggest a mutual influence of NA and SA on their permeation across the skin from an innovative transdermal film. The partition coefficient obtained when the two molecules were simultaneously present was typically lower than the respective value obtained with NA and SA alone.

  8. Root-fed salicylic acid in grape involves the response caused by aboveground high temperature.

    PubMed

    Liu, Hong-Tao; Liu, Yue-Ping; Huang, Wei-Dong

    2008-06-01

    In order to investigate the transportation and distribution of salicylic acid (SA) from root to aboveground tissues in response to high temperature, the roots of grape plant were fed with (14)C-SA before high temperature treatment. Radioactivity results showed that progressive increase in SA transportation from root to aboveground as compared with the control varied exactly with the heat treatment time. Radioactivity results of leaves at different stem heights indicated that the increase in SA amount at the top and middle leaves during the early period was most significant in comparison with the bottom leaves. The up-transportation of SA from root to aboveground tissues was dependent on xylem rather than phloem. Auto-radiographs of whole grape plants strongly approved the conclusions drawn above. Root-derived SA was believed to be a fundamental source in response to aboveground high temperature.

  9. Fluorescence characteristics of 5-amino salicylic acid: An iodide recognition study.

    PubMed

    Arora, Priyanka; Suyal, Kanchan; Joshi, Neeraj K; Joshi, Hem Chandra; Pant, Sanjay

    2012-08-01

    In this paper we report the effect of iodide on the fluorescence of 5-amino salicylic acid (5-ASA). In the absence of iodide, prominent blue green (BG) emission band at ∼465nm (broad) is observed in aprotic solvents whereas violet (V) emission at ∼408nm, blue green (BG) at ∼480nm and green (G) at ∼500nm are observed in case of protic solvents. On the addition of iodide ion (I(-)), the intensity of BG fluorescence is enhanced in case of aprotic solvents. On the other hand the G band is enhanced in protic solvents and decrease in the intensity of the V band is observed. The effect of hydrogen bonding as well as the interplay of neutral and ionic species is invoked to explain the observed results. The study projects the application of this system in iodide recognition in protic/aprotic environments.

  10. Spectroscopic studies of solid-state forms of donepezil free base and salt forms with various salicylic acids

    NASA Astrophysics Data System (ADS)

    Brittain, Harry G.

    2014-12-01

    The polymorphic forms of donepezil free base have been studied using X-ray powder diffraction, Fourier transform infrared absorption spectroscopy, and differential scanning calorimetry. None of the free base crystal forms was observed to exhibit detectable fluorescence in the solid state under ambient conditions. Crystalline salt products were obtained by the reaction of donepezil with salicylic and methyl-substituted salicylic acids, with the salicylate and 4-methylsalicylate salts being obtained as non-solvated products, and the 3-methylsalicylate and 5-methylsalicylate salts being obtained as methanol solvated products. The intensity of solid-state fluorescence from donepezil salicylate and donepezil 4-methylsalicylate was found to be reduced relative to the fluorescence intensity of the corresponding free acids, while the solid-state fluorescence intensity of donepezil 3-methylsalicylate methanolate and donepezil 5-methylsalicylate methanolate was greatly increased relative to the fluorescence intensity of the corresponding free acids. Desolvation of the solvated salt products led to formation of glassy solids that exhibited strong green fluorescence.

  11. Enhanced degradation of Herbicide Isoproturon in wheat rhizosphere by salicylic acid.

    PubMed

    Lu, Yi Chen; Zhang, Shuang; Miao, Shan Shan; Jiang, Chen; Huang, Meng Tian; Liu, Ying; Yang, Hong

    2015-01-14

    This study investigated the herbicide isoproturon (IPU) residues in soil, where wheat was cultivated and sprayed with salicylic acid (SA). Provision of SA led to a lower level of IPU residues in rhizosphere soil compared to IPU treatment alone. Root exudation of tartaric acid, malic acid, and oxalic acids was enhanced in rhizosphere soil with SA-treated wheat. We examined the microbial population (e.g., biomass and phospholipid fatty acid), microbial structure, and soil enzyme (catalase, phenol oxidase, and dehydrogenase) activities, all of which are associated with soil activity and were activated in rhizosphere soil of SA-treated wheat roots. We further assessed the correlation matrix and principal component to figure out the association between the IPU degradation and soil activity. Finally, six IPU degraded products (derivatives) in rhizosphere soil were characterized using ultraperformance liquid chromatography with a quadrupole-time-of-flight tandem mass spectrometer (UPLC/Q-TOF-MS/MS). A relatively higher level of IPU derivatives was identified in soil with SA-treated wheat than in soil without SA-treated wheat plants.

  12. Salicylic acid alleviates NaCl-induced changes in the metabolism of Matricaria chamomilla plants.

    PubMed

    Kovácik, Jozef; Klejdus, Borivoj; Hedbavny, Josef; Backor, Martin

    2009-07-01

    Influence of 100 mM NaCl and 50 microM salicylic acid (SA) and their combination on the metabolism of chamomile (Matricaria chamomilla) during 7 days was studied. NaCl reduced growth and selected physiological parameters and SA in combined treatment (NaCl + SA) reversed majority of these symptoms. Application of SA reduced NaCl-induced increase of Na+ in the rosettes, but not in the roots. Accumulation of total amino acids was stimulated in NaCl-treated roots, especially due to exceptional increase of proline (4.4-fold). Among phenolic acids, accumulation of protocatechuic acid was the most enhanced in NaCl-exposed leaf rosettes (ca. 3-fold) while chlorogenic and caffeic acids in the roots (2.4- and 2.8-fold, respectively). Total soluble phenols increased after NaCl and SA treatments, but root lignin content was not affected. Activity of phenylalanine ammonia-lyase and shikimate dehydrogenase increased in response to NaCl, but cinnamyl alcohol dehydrogenase was not affected and polyphenol oxidase decreased. Stress parameters were elevated by NaCl treatment (superoxide radical and malondialdehyde content, activities of catalase, ascorbate- and guaiacol-peroxidase) and substantially prevented by SA, while accumulation of hydrogen peroxide decreased. Overall, SA showed strong beneficial properties against NaCl-induced negative symptoms. Protective effect of SA was the most visible at the level of guaiacol-peroxidase and through amelioration of stress parameters and mineral nutrient contents.

  13. Analysis of salicylic acid-dependent pathways in Arabidopsis thaliana following infection with Plasmodiophora brassicae and the influence of salicylic acid on disease.

    PubMed

    Lovelock, David A; Šola, Ivana; Marschollek, Sabine; Donald, Caroline E; Rusak, Gordana; van Pée, Karl-Heinz; Ludwig-Müller, Jutta; Cahill, David M

    2016-10-01

    Salicylic acid (SA) biosynthesis, the expression of SA-related genes and the effect of SA on the Arabidopsis-Plasmodiophora brassicae interaction were examined. Biochemical analyses revealed that, in P. brassicae-infected Arabidopsis, the majority of SA is synthesized from chorismate. Real-time monitored expression of a gene for isochorismate synthase was induced on infection. SA can be modified after accumulation, either by methylation, improving its mobility, or by glycosylation, as one possible reaction for inactivation. Quantitative reverse transcription-polymerase chain reaction (qPCR) confirmed the induction of an SA methyltransferase gene, whereas SA glucosyltransferase expression was not changed after infection. Col-0 wild-type (wt) did not provide a visible phenotypic resistance response, whereas the Arabidopsis mutant dnd1, which constitutively activates the immune system, showed reduced gall scores. As dnd1 showed control of the pathogen, exogenous SA was applied to Arabidopsis in order to test whether it could suppress clubroot. In wt, sid2 (SA biosynthesis), NahG (SA-deficient) and npr1 (SA signalling-impaired) mutants, SA treatment did not alter the gall score, but positively affected the shoot weight. This suggests that SA alone is not sufficient for Arabidopsis resistance against P. brassicae. Semi-quantitative PCR revealed that wt, cpr1, dnd1 and sid2 showed elevated PR-1 expression on P. brassicae and SA + P. brassicae inoculation at 2 and 3 weeks post-inoculation (wpi), whereas NahG and npr1 showed no expression. This work contributes to the understanding of SA involvement in the Arabidopsis-P. brassicae interaction.

  14. Complexation efficiency of differently fixed 8-hydroxyquinoline and salicylic acid ligand groups for labile aluminium species determination in soils--comparison of two methods.

    PubMed

    Matús, Peter; Kubová, Jana

    2006-07-28

    Two methods utilizing the complexation of labile Al species by 8-hydroxyquinoline (HQN) and salicylic acid (SA) ligand groups were developed for aluminium operationally defined fractionation in acid soils. First, the solid phase extraction (SPE) procedure by a short-term ion-exchange batch reaction with chelating resins Iontosorb Oxin and Iontosorb Salicyl containing both ligand groups was used previously. Second, the 8-hydroxyquinoline, salicylic acid and ammonium salicylate agents with different concentrations by a single extraction protocol were applied in this paper. The flame atomic absorption spectrometry (FAAS) and optical emission spectrometry with inductively coupled plasma were used for aluminium quantification. The comparison of results from both methods show the possibility to supersede the first laborious method for the second simpler one in Al environmental risk assessment. The use of 1% 8-hydroxyquinoline in 2% acetic acid and 0.2% salicylic acid by a single extraction protocol without a need of sample filtration can supersede the SPE procedure in the Al pollution soil monitoring. Finally, the new scheme usable in a laboratory and moreover, directly in a field was proposed for Al fractionation in solid and liquid environmental samples. The labile Al species in soils and sediments are separated after their single leaching by 8-hydroxyquinoline or salicylic acid without a need of sample filtration. The labile Al species in soil solutions and natural waters are separated after their ultrafiltration followed by the SPE procedure with Iontosorb Oxin or Iontosorb Salicyl.

  15. Research on the adsorption property of supported ionic liquids for ferulic acid, caffeic acid and salicylic acid.

    PubMed

    Du, Ni; Cao, Shuwen; Yu, Yanying

    2011-06-01

    In this paper, the preparation of new supported ionic liquids (SILs) composed of the N-methylimidazolium cation and the quinoline cation is described. They have been confirmed and evaluated by infrared spectroscopy, elemental analysis and thermogravimetric analysis. Six kinds of different SILs included SiO(2)·Im(+)·Cl(-), SiO(2)·Im(+)·BF(4)(-), SiO(2)·Im(+)·PF(6)(-), SiO(2)·Qu(+)·Cl(-), SiO(2)·Qu(+)·BF(4)(-) and SiO(2)·Qu(+)·PF(6)(-). The adsorption characteristics of ferulic acid (FA), caffeic acid (CA) and salicylic acid (SA) on SILs were investigated by static adsorption experiments. It was found that SiO(2)·Qu(+)·Cl(-) had excellent adsorption and desorption capacity to three tested phenolic compounds. The dynamic adsorption characteristics of FA, CA and SA on SiO(2)·Qu(+)·Cl(-) were also studied. The saturated adsorption capacity of FA, CA and SA using SiO(2)·Qu(+)·Cl(-) as adsorbent was 64.6 mg/g, 53.2 mg/g and 72.2 mg/g respectively. Using 70% ethanol as eluent, the saturated desorption efficiencies of FA, CA and SA were 97.2%, 90.3% and 96.5% respectively. Thus, SiO(2)·Qu(+)·Cl(-) had strong adsorption and separation capacity for FA, CA and SA.

  16. Ectopic expression of Arabidopsis genes encoding salicylic acid- and jasmonic acid-related proteins confers partial resistance to soybean cyst nematode (Heterodera glycines) in transgenic soybean roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background. Extensive studies using the model system Arabidopsis thaliana to elucidate plant defense signaling and pathway networks indicate that salicylic acid (SA) is the key hormone triggering the plant defense response against biotrophic and hemi-biotrophic pathogens, while jasmonic acid (JA) an...

  17. Exogenous salicylic acid protects phospholipids against cadmium stress in flax (Linum usitatissimum L.).

    PubMed

    Belkadhi, Aïcha; De Haro, Antonio; Obregon, Sara; Chaïbi, Wided; Djebali, Wahbi

    2015-10-01

    Salicylic acid (SA) promotes plant defense responses against toxic metal stresses. The present study addressed the hypothesis that 8-h SA pretreatment, would alter membrane lipids in a way that would protect against Cd toxicity. Flax seeds were pre-soaked for 8h in SA (0, 250 and 1000µM) and then subjected, at seedling stage, to cadmium (Cd) stress. At 100µM CdCl2, significant decreases in the percentages of phosphatidylcholine (PC), phosphatidylglycerol (PG), phosphatidylethanolamine (PE) and monogalactosyldiacylglycerol (MGDG) and changes in their relative fatty acid composition were observed in Cd-treated roots in comparison with controls. However, in roots of 8-h SA pretreated plantlets, results showed that the amounts of PC and PE were significantly higher as compared to non-pretreated plantlets. Additionally, in both lipid classes, the proportion of linolenic acid (18:3) increased upon the pretreatment with SA. This resulted in a significant increase in the fatty acid unsaturation ratio of the root PC and PE classes. As the exogenous application of SA was found to be protective of flax lipid metabolism, the possible mechanisms of protection against Cd stress in flax roots were discussed.

  18. Proline induces calcium-mediated oxidative burst and salicylic acid signaling.

    PubMed

    Chen, Jiugeng; Zhang, Yueqin; Wang, Cuiping; Lü, Weitao; Jin, Jing Bo; Hua, Xuejun

    2011-05-01

    Although free proline accumulation is a well-documented phenomenon in many plants in response to a variety of environmental stresses, and is proposed to play protective roles, high intracellular proline content, by either exogenous application or endogenous over-production, in the absence of stresses, is found to be inhibitory to plant growth. We have shown here that exogenous application of proline significantly induced intracellular Ca(2+) accumulation in tobacco and calcium-dependent ROS production in Arabidopsis seedlings, which subsequently enhanced salicylic acid (SA) synthesis and PR genes expression. This suggested that proline can promote a reaction similar to hypersensitive response during pathogen infection. Other amino acids, such as glutamate, but not arginine and phenylalanine, were also found to be capable of inducing PR gene expression. In addition, proline at concentration as low as 0.5 mM could induce PR gene expression. However, proline could not induce the expression of PDF1.2 gene, the marker gene for jasmonic acid signaling pathway. Furthermore, proline-induced SA production is mediated by NDR1-dependent signaling pathway, but not that mediated by PAD4. Our data provide evidences that exogenous proline, and probably some other amino acids can specifically induce SA signaling and defense response.

  19. Anion-Channel Blockers Inhibit S-Type Anion Channels and Abscisic Acid Responses in Guard Cells.

    PubMed Central

    Schwartz, A.; Ilan, N.; Schwarz, M.; Scheaffer, J.; Assmann, S. M.; Schroeder, J. I.

    1995-01-01

    The effects of anion-channel blockers on light-mediated stomatal opening, on the potassium dependence of stomatal opening, on stomatal responses to abscisic acid (ABA), and on current through slow anion channels in the plasma membrane of guard cells were investigated. The anion-channel blockers anthracene-9-carboxylic acid (9-AC) and niflumic acid blocked current through slow anion channels of Vicia faba L. guard cells. Both 9-AC and niflumic acid reversed ABA inhibition of stomatal opening in V. faba L. and Commelina communis L. The anion-channel blocker probenecid also abolished ABA inhibition of stomatal opening in both species. Additional tests of 9-AC effects on stomatal aperture in Commelina revealed that application of this anion-channel blocker allowed wide stomatal opening under low (1 mM) KCI conditions and increased the rate of stomatal opening under both low and high (100 mM) KCI conditions. These results indicate that anion channels can function as a negative regulator of stomatal opening, presumably by allowing anion efflux and depolarization, which prohibits ion up-take in guard cells. Furthermore, 9-AC prevented ABA induction of stomatal closure. A model in which ABA activation of anion channels contributes a rate-limiting mechanism during ABA-induced stomatal closure and inhibition of stomatal opening is discussed. PMID:12228619

  20. Strong regulation of slow anion channels and abscisic acid signaling in guard cells by phosphorylation and dephosphorylation events.

    PubMed Central

    Schmidt, C; Schelle, I; Liao, Y J; Schroeder, J I

    1995-01-01

    Recent evidence suggests that slow anion channels in guard cells need to be activated to trigger stomatal closing and efficiently inactivated during stomatal opening. The patch-clamp technique was employed here to determine mechanisms that produce strong regulation of slow anion channels in guard cells. MgATP in guard cells, serving as a donor for phosphorylation, leads to strong activation of slow anion channels. Slow anion-channel activity was almost completely abolished by removal of cytosolic ATP or by the kinase inhibitors K-252a and H7. Nonhydrolyzable ATP, GTP, and guanosine 5'-[gamma-thio]triphosphate did not replace the ATP requirement for anion-channel activation. In addition, down-regulation of slow anion channels by ATP removal was inhibited by the phosphatase inhibitor okadaic acid. Stomatal closures in leaves induced by the plant hormone abscisic acid (ABA) and malate were abolished by kinase inhibitors and/or enhanced by okadaic acid. These data suggest that ABA signal transduction may proceed by activation of protein kinases and inhibition of an okadaic acid-sensitive phosphatase. This modulation of ABA-induced stomatal closing correlated to the large dynamic range for up- and down-regulation of slow anion channels by opposing phosphorylation and dephosphorylation events in guard cells. The presented opposing regulation by kinase and phosphatase modulators could provide important mechanisms for signal transduction by ABA and other stimuli during stomatal movements. PMID:11607582

  1. Anion-Channel Blockers Inhibit S-Type Anion Channels and Abscisic Acid Responses in Guard Cells.

    PubMed

    Schwartz, A.; Ilan, N.; Schwarz, M.; Scheaffer, J.; Assmann, S. M.; Schroeder, J. I.

    1995-10-01

    The effects of anion-channel blockers on light-mediated stomatal opening, on the potassium dependence of stomatal opening, on stomatal responses to abscisic acid (ABA), and on current through slow anion channels in the plasma membrane of guard cells were investigated. The anion-channel blockers anthracene-9-carboxylic acid (9-AC) and niflumic acid blocked current through slow anion channels of Vicia faba L. guard cells. Both 9-AC and niflumic acid reversed ABA inhibition of stomatal opening in V. faba L. and Commelina communis L. The anion-channel blocker probenecid also abolished ABA inhibition of stomatal opening in both species. Additional tests of 9-AC effects on stomatal aperture in Commelina revealed that application of this anion-channel blocker allowed wide stomatal opening under low (1 mM) KCI conditions and increased the rate of stomatal opening under both low and high (100 mM) KCI conditions. These results indicate that anion channels can function as a negative regulator of stomatal opening, presumably by allowing anion efflux and depolarization, which prohibits ion up-take in guard cells. Furthermore, 9-AC prevented ABA induction of stomatal closure. A model in which ABA activation of anion channels contributes a rate-limiting mechanism during ABA-induced stomatal closure and inhibition of stomatal opening is discussed.

  2. Pathogen-induced systemic activation of a plant defensin gene in Arabidopsis follows a salicylic acid-independent pathway.

    PubMed Central

    Penninckx, I A; Eggermont, K; Terras, F R; Thomma, B P; De Samblanx, G W; Buchala, A; Métraux, J P; Manners, J M; Broekaert, W F

    1996-01-01

    A 5-kD plant defensin was purified from Arabidopsis leaves challenged with the fungus Alternaria brassicicola and shown to possess antifungal properties in vitro. The corresponding plant defensin gene was induced after treatment of leaves with methyl jasmonate or ethylene but not with salicylic acid or 2,6-dichloroisonicotinic acid. When challenged with A. brassicicola, the levels of the plant defensin protein and mRNA rose both in inoculated leaves and in nontreated leaves of inoculated plants (systemic leaves). These events coincided with an increase in the endogenous jasmonic acid content of both types of leaves. Systemic pathogen-induced expression of the plant defensin gene was unaffected in Arabidopsis transformants (nahG) or mutants (npr1 and cpr1) affected in the salicylic acid response but was strongly reduced in the Arabidopsis mutants eln2 and col1 that are blocked in their response to ethylene and methyl jasmonate, respectively. Our results indicate that systemic pathogen-induced expression of the plant defensin gene in Arabidopsis is independent of salicylic acid but requires components of the ethylene and jasmonic acid response. PMID:8989885

  3. Effect of salicylic acid treatment on postharvest quality, antioxidant activities, and free polyamines of asparagus.

    PubMed

    Wei, Yunxiao; Liu, Zhenfeng; Su, Yujing; Liu, Donghong; Ye, Xingqian

    2011-03-01

    The effects of salicylic acid (SA) on the quality and antioxidant activity of asparagus stored at 18 ± 2 °C were investigated by analyzing the color, chlorophyll, shear force, and the activity of antioxidant compounds such as ascorbic acid, phenolics, flavonoids, 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity ferric reducing antioxidant power (FRAP), and polyamines (PAs). The results showed that SA improved the color and maintained the chlorophyll, phenolic, flavonoid, and ascorbic acid content of asparagus. High concentrations of SA caused a deterioration in asparagus would harm to color and had no effect on shear force within 6 d. SA induced the maximum concentration of phenolics in postharvest asparagus, promoted the increase in total flavonoids before 6 to 9 d, affected the antioxidant activity positively as indicated by the resultant increase in FRAP concentration; however, SA was only active with regard to DPPH scavenging activity within 6 d of treatment. Spermidine (Spd) is the most common form of PA in asparagus, and free putrescine (Put) contents increased over the first 3 d following harvest and then decreased. Spd and Spm concentrations evolved in a similar way and decreased during storage. Higher Spd and Spm contents in the SA pre-treatment Put was inhabited and its peaks appeared later.

  4. Salicylic acid-induced changes to growth and phenolic metabolism in Matricaria chamomilla plants.

    PubMed

    Kovácik, Jozef; Grúz, Jirí; Backor, Martin; Strnad, Miroslav; Repcák, Miroslav

    2009-01-01

    The influence of salicylic acid (SA) doses of 50 and 250 microM, for a period of up to 7 days, on selected physiological aspects and the phenolic metabolism of Matricaria chamomilla plants was studied. SA exhibited both growth-promoting (50 microM) and growth-inhibiting (250 microM) properties, the latter being correlated with decrease of chlorophylls, water content and soluble proteins. In terms of phenolic metabolism, it seems that the higher SA dose has a toxic effect, based on the sharp increase in phenylalanine ammonia-lyase (PAL) activity (24 h after application), which is followed by an increase in total soluble phenolics, lignin accumulation and the majority of the 11 detected phenolic acids. Guaiacol-peroxidase activity was elevated throughout the experiment in 250 microM SA-treated plants. In turn, some responses can be explained by mechanisms associated with oxidative stress tolerance; these mitigate acute SA stress (which is indicated by an increase in malondialdehyde content). However, PAL activity decreased with prolonged exposure to SA, indicating its inhibition. Accumulation of coumarin-related compounds (umbelliferone and herniarin) was not affected by SA treatments, while (Z)- and (E)-2-beta-D: -glucopyranosyloxy-4-methoxycinnamic acids increased in the 250 microM SA-treated rosettes. Free SA content in the rosettes increased significantly only in the 250 microM SA treatment, with levels tending to decrease towards the end of the experiment and the opposite trend was observed in the roots.

  5. Salicylic Acid induces cyanide-resistant respiration in tobacco cell-suspension cultures.

    PubMed

    Kapulnik, Y; Yalpani, N; Raskin, I

    1992-12-01

    Cyanide-resistant, alternative respiration in Nicotiana tabacum L. cv Xanthi-nc was analyzed in liquid suspension cultures using O(2) uptake and calorimetric measurements. In young cultures (4-8 d after transfer), cyanide inhibited O(2) uptake by up to 40% as compared to controls. Application of 20 mum salicylic acid (SA) to young cells increased cyanide-resistant O(2) uptake within 2 h. Development of KCN resistance did not affect total O(2) uptake, but was accompanied by a 60% increase in the rate of heat evolution from cells as measured by calorimetry. This stimulation of heat evolution by SA was not significantly affected by 1 mm cyanide, but was reduced by 10 mm salicylhydroxamic acid (SHAM), an inhibitor of cyanide-resistant respiration. Treatment of SA-induced or uninduced cells with a combination of cyanide and SHAM blocked most of the O(2) consumption and heat evolution. Fifty percent of the applied SA was taken up within 10 min, with most of the intracellular SA metabolized in 2 h. 2,6-Dihydroxybenzoic and 4-hydroxybenzoic acids also induced cyanide-resistant respiration. These data indicate that in tobacco cell-suspension culture, SA induces the activity and the capacity of cyanide-resistant respiration without affecting the capacity of the cytochrome c respiration pathway.

  6. 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

  7. Kinetic Characterisation of a Single Chain Antibody against the Hormone Abscisic Acid: Comparison with Its Parental Monoclonal

    PubMed Central

    Badescu, George O.; Marsh, Andrew; Smith, Timothy R.; Thompson, Andrew J.; Napier, Richard M.

    2016-01-01

    A single-chain Fv fragment antibody (scFv) specific for the plant hormone abscisic acid (ABA) has been expressed in the bacterium Escherichia coli as a fusion protein. The kinetics of ABA binding have been measured using surface plasmon resonance spectrometry (BIAcore 2000) using surface and solution assays. Care was taken to calculate the concentration of active protein in each sample using initial rate measurements under conditions of partial mass transport limitation. The fusion product, parental monoclonal antibody and the free scFv all have low nanomolar affinity constants, but there is a lower dissociation rate constant for the parental monoclonal resulting in a three-fold greater affinity. Analogue specificity was tested and structure-activity binding preferences measured. The biologically-active (+)-ABA enantiomer is recognised with an affinity three orders of magnitude higher than the inactive (-)-ABA. Metabolites of ABA including phaseic acid, dihydrophaseic acid and deoxy-ABA have affinities over 100-fold lower than that for (+)-ABA. These properties of the scFv make it suitable as a sensor domain in bioreporters specific for the naturally occurring form of ABA. PMID:27023768

  8. Extending shikimate pathway for the production of muconic acid and its precursor salicylic acid in Escherichia coli.

    PubMed

    Lin, Yuheng; Sun, Xinxiao; Yuan, Qipeng; Yan, Yajun

    2014-05-01

    cis,cis-Muconic acid (MA) and salicylic acid (SA) are naturally-occurring organic acids having great commercial value. MA is a potential platform chemical for the manufacture of several widely-used consumer plastics; while SA is mainly used for producing pharmaceuticals (for example, aspirin and lamivudine) and skincare and haircare products. At present, MA and SA are commercially produced by organic chemical synthesis using petro-derived aromatic chemicals, such as benzene, as starting materials, which is not environmentally friendly. Here, we report a novel approach for efficient microbial production of MA via extending shikimate pathway by introducing the hybrid of an SA biosynthetic pathway with its partial degradation pathway. First, we engineered a well-developed phenylalanine producing Escherichia coli strain into an SA overproducer by introducing isochorismate synthase and isochorismate pyruvate lyase. The engineered strain is able to produce 1.2g/L of SA from simple carbon sources, which is the highest titer reported so far. Further, the partial SA degradation pathway involving salicylate 1-monoxygenase and catechol 1,2-dioxygenase is established to achieve the conversion of SA to MA. Finally, a de novo MA biosynthetic pathway is assembled by integrating the established SA biosynthesis and degradation modules. Modular optimization enables the production of up to 1.5g/L MA within 48h in shake flasks. This study not only establishes an efficient microbial platform for the production of SA and MA, but also demonstrates a generalizable pathway design strategy for the de novo biosynthesis of valuable degradation metabolites.

  9. Research Advances. Image Pinpoints All 5 Million Atoms in Viral Coat; Bilirubin, "Animals-Only" Pigment, Found in Plants; New Evidence Shows Humans Make Salicylic Acid

    NASA Astrophysics Data System (ADS)

    King, Angela G.

    2009-08-01

    Recent "firsts" in chemical research: image of a viral capsid pinpointing 5 million atoms; isolation and identification of an "animal" pigment, bilirubin, from a plant source; evidence that humans make salicylic acid.

  10. Effect of salicylic acid upon trace-metal sorption (Cd, Zn, Co, and Mn) onto alumina, silica, and kaolinite as a function of pH

    SciTech Connect

    Benyahya, L.; Garnier, J.M.

    1999-05-01

    The sorption of four trace metals (Cd, Zn, Co, and Mn) onto alumina, silica, and kaolinite, in the presence or absence of salicylic acid was investigated in batch experiments in the pH range from 4 to 9. The sorption was interpreted in terms of surface complexation using the diffuse layer model (DLM). Equilibrium parameters were optimized using the FITEQL program. The salicylic acid was only significantly sorbed onto the alumina and the sorption was modeled using the anionic monodentate surface complex. In the absence of salicylic acid, the sorption of the trace metals presented different pH edge behaviors, depending on the substrate. Using the cationic monodendate surface complex, the model fitted the experimental data well. In the presence of salicylic acid, at a given pH and depending on the substrate, the sorption of metals was (1) increased, suggesting the occurrence of ternary complexes; (2) reduced (sometimes totally inhibited), due to the complexation with dissolved salicylic acid; or (3) very weakly changed in terms of net effect compared to free-organic-ligand systems. Modeling of the trace-metal sorption in the presence of salicylic acid was performed using ternary surface complexes. In the acidic pH range, this allowed the experimental data to be simulated, but in the alkaline pH range, the model failed to simulate the decrease in sorption. Probable causes of the discrepancies between the experimental data and modeling results are discussed.

  11. Preparation of magnetic dummy molecularly imprinted polymers for selective extraction and analysis of salicylic acid in Actinidia chinensis.

    PubMed

    You, Qing-Ping; Peng, Mi-Jun; Zhang, Yu-Ping; Guo, Jun-Fang; Shi, Shu-Yun

    2014-01-01

    Compounds with strong intramolecular hydrogen bonds (e.g., salicylic acid) have weak intermolecular hydrogen bonding interactions between them and functional monomers in the imprinting process. Consequently, the corresponding molecularly imprinted polymers (MIPs) have no specific adsorption ability. Here, the first magnetic dummy MIPs (MDMIPs) based on benzonic acid as dummy template are successfully developed and evaluated with respect to the applications in selective enrichment and analysis of salicylic acid from complex mixtures. Various parameters affecting absorption/desorption were evaluated for achieving optimal recovery and reducing nonspecific interactions. The prepared MDMIPs showed high adsorption capacity, good selectivity, rapid kinetic binding (40 min) and magnetic separation (5 s), high reproducibility (RSD< 4 % for batch-to-batch evaluation), and stability (only 4 % decrease after 6 cycles). Owing to the efficacy in specific binding and removal of interference, trace level salicylic acid was quantified (0.2 μg/g of fresh mass) in Actinidia chinensis by high-performance liquid chromatography.

  12. Nup82 functions redundantly with Nup136 in a salicylic acid-dependent defense response of Arabidopsis thaliana.

    PubMed

    Tamura, Kentaro; Fukao, Yoichiro; Hatsugai, Noriyuki; Katagiri, Fumiaki; Hara-Nishimura, Ikuko

    2017-01-10

    The nuclear pore complex (NPC) comprises more than 30 nucleoporins (Nups). NPC mediates macromolecular trafficking between the nucleoplasm and the cytoplasm, but specific roles of individual Nups are poorly understood in higher plants. Here, we show that the novel nucleoporin unique to angiosperm plants (designated as Nup82) functions in a salicylic acid-dependent defense in a redundant manner with Nup136, which is a component of the nuclear basket in the NPC. Arabidopsis thaliana Nup82 had a similar amino acid sequence to the N-terminal half of Nup136 and a Nup82-GFP fusion was localized on the nuclear envelope. Immunoprecipitation and bimolecular fluorescence complementation analyses revealed that Nup82 interacts with the NPC components Nup136 and RAE1. The double knockout mutant nup82 nup136 showed severe growth defects, while the single knockout mutant nup82 did not, suggesting that Nup82 functions redundantly with Nup136. nup82 nup136 impaired benzothiadiazole (an analog of salicylic acid)-induced resistance to the virulent bacteria Pseudomonas syringae pv. tomato DC3000. Furthermore, transcriptome analysis of nup82 nup136 indicates that deficiency of Nup82 and Nup136 causes noticeable downregulation of immune-related genes. These results suggest that Nup82 and Nup136 are redundantly involved in transcriptional regulation of salicylic acid-responsive genes through nuclear transport of signaling molecules.

  13. 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.

  14. Mercaptopropionic acid-capped CdTe quantum dots as fluorescence probe for the determination of salicylic acid in pharmaceutical products.

    PubMed

    Bunkoed, Opas; Kanatharana, Proespichaya

    2015-11-01

    Mercaptopropionic acid (MPA)-capped cadmium telluride (CdTe) quantum dot (QDs) fluorescent probes were synthesized in aqueous solution and used for the determination of salicylic acid. The interaction between the MPA-capped CdTe QDs and salicylic acid was studied using fluorescence spectroscopy and some parameters that could modify the fluorescence were investigated to optimize the measurements. Under optimum conditions, the quenched fluorescence intensity of MPA-capped CdTe QDs was linearly proportional to the concentration of salicylic acid in the range of 0.5-40 µg mL(-1) with a coefficient of determination of 0.998, and the limit of detection was 0.15 µg mL(-1). The method was successfully applied to the determination of salicylic acid in pharmaceutical products, and satisfactory results were obtained that were in agreement with both the high pressure liquid chromatography (HPLC) method and the claimed values. The recovery of the method was in the range 99 ± 3% to 105 ± 9%. The proposed method is simple, rapid, cost effective, highly sensitivity and eminently suitable for the quality control of pharmaceutical preparation. The possible mechanisms for the observed quenching reaction was also discussed.

  15. Characterization of an inducible UDP-glucose:salicylic acid O-glucosyltransferase from oat roots

    SciTech Connect

    Yalpani, N.; Schulz, M.; Balke, N.E. )

    1990-05-01

    Phytotoxicity of salicylic acid (SA), a phenolic acid that inhibits ion absorption in plant roots, is reduced in oat roots by the action of a UDP-glucose:SA glucosyltransferase (GTase). GTase activity, extracted from oat roots and assayed with ({sup 14}C)SA, was present at low constitutive levels but increased within 1.5 h of incubation of roots in 0.5 mM SA at pH 6.5. This induction was the result of de novo RNA and protein synthesis. Induction was highly specific towards SA as the inducer. The partially purified, soluble enzyme has a M{sub t} of about 50,000 and high specificity towards UDP-glucose as the sugar donor (K{sub m} = 0.28 mM) and SA as the glucose acceptor (K{sub m} = 0.11 mM). 2-D PAGE of ({sup 35}S)methionine-labeled proteins extracted from induced and uninduced roots revealed a candidate peptide representing the GTase. This peptide was also present on gels of partially purified GTase.

  16. Plant immunity induced by COS-OGA elicitor is a cumulative process that involves salicylic acid.

    PubMed

    van Aubel, Géraldine; Cambier, Pierre; Dieu, Marc; Van Cutsem, Pierre

    2016-06-01

    Plant innate immunity offers considerable opportunities for plant protection but beside flagellin and chitin, not many molecules and their receptors have been extensively characterized and very few have successfully reached the field. COS-OGA, an elicitor that combines cationic chitosan oligomers (COS) with anionic pectin oligomers (OGA), efficiently protected tomato (Solanum lycopersicum) grown in greenhouse against powdery mildew (Leveillula taurica). Leaf proteomic analysis of plants sprayed with COS-OGA showed accumulation of Pathogenesis-Related proteins (PR), especially subtilisin-like proteases. qRT-PCR confirmed upregulation of PR-proteins and salicylic acid (SA)-related genes while expression of jasmonic acid/ethylene-associated genes was not modified. SA concentration and class III peroxidase activity were increased in leaves and appeared to be a cumulative process dependent on the number of sprayings with the elicitor. These results suggest a systemic acquired resistance (SAR) mechanism of action of the COS-OGA elicitor and highlight the importance of repeated applications to ensure efficient protection against disease.

  17. Salicylic-acid elicited phospholipase D responses in Capsicum chinense cell cultures.

    PubMed

    Rodas-Junco, B A; Muñoz-Sánchez, J A; Vázquez-Flota, F; Hernández-Sotomayor, S M T

    2015-05-01

    The plant response to different stress types can occur through stimulus recognition and the subsequent signal transduction through second messengers that send information to the regulation of metabolism and the expression of defense genes. The phospholipidic signaling pathway forms part of the plant response to several phytoregulators, such as salicylic acid (SA), which has been widely used to stimulate secondary metabolite production in cell cultures. In this work, we studied the effects of SA treatment on [(32)-P]Pi phospholipid turnover and phospholipase D (PLD) activity using cultured Capsicum chinense cells. In cultured cells, the PIP2 turnover showed changes after SA treatment, while the most abundant phospholipids (PLs), such as phosphatidylcholine (PC), did not show changes during the temporal course. SA treatment significantly increased phosphatidic acid (PA) turnover over time compared to control cells. The PA accumulation in cells treated with 1-butanol showed a decrease in messengers; at the same time, there was a 1.5-fold increase in phosphatidylbutanol. These results suggest that the participation of the PLD pathway is a source of PA production, and the activation of this mechanism may be important in the cell responses to SA treatment.

  18. Identification of didecyldimethylammonium salts and salicylic acid as antimicrobial compounds in commercial fermented radish kimchi.

    PubMed

    Li, Jing; Chaytor, Jennifer L; Findlay, Brandon; McMullen, Lynn M; Smith, David C; Vederas, John C

    2015-03-25

    Daikon radish (Raphanus sativus) fermented with lactic acid bacteria, especially Leuconostoc or Lactobacillus spp., can be used to make kimchi, a traditional Korean fermented vegetable. Commercial Leuconostoc/radish root ferment filtrates are claimed to have broad spectrum antimicrobial activity. Leuconostoc kimchii fermentation products are patented as preservatives for cosmetics, and certain strains of this organism are reported to produce antimicrobial peptides (bacteriocins). We examined the antimicrobial agents in commercial Leuconostoc/radish root ferment filtrates. Both activity-guided fractionation with Amberlite XAD-16 and direct extraction with ethyl acetate gave salicylic acid as the primary agent with activity against Gram-negative bacteria. Further analysis of the ethyl acetate extract revealed that a didecyldimethylammonium salt was responsible for the Gram-positive activity. The structures of these compounds were confirmed by a combination of (1)H- and (13)C NMR, high-performance liquid chromatography, high-resolution mass spectrometry, and tandem mass spectrometry analyses. Radiocarbon dating indicates that neither compound is a fermentation product. No antimicrobial peptides were detected.

  19. Efficacy of salicylic acid to reduce Penicillium expansum inoculum and preserve apple fruits.

    PubMed

    da Rocha Neto, Argus Cezar; Luiz, Caroline; Maraschin, Marcelo; Di Piero, Robson Marcelo

    2016-03-16

    Apples are among the most commonly consumed fruits worldwide. Blue mold (Penicillium expansum) is one of the major diseases in apples postharvest, leading to wide use of fungicides and the search for alternative products to control the pathogen. In this context, this study aimed to evaluate the potential of salicylic acid (SA) as an alternative product to control blue mold and to preserve the physicochemical characteristics of apple fruit postharvest. The antimicrobial effect of SA was determined both in vitro and in situ, by directly exposing conidia to solutions of different concentrations SA or by inoculating the fruit with P. expansum and treating them curatively, eradicatively, or preventively with a 2.5mM SA solution. The physiological effects of SA on fruit were determined by quantifying the weight loss, total soluble solids content, and titratable acidity. In addition, the accumulation of SA in the fruit was determined by HPLC. SA (2.5mM) inhibited 100% of fungal germination in vitro and also controlled blue mold in situ when applied eradicatively. In addition, HPLC analysis demonstrated that SA did not persist in apple fruit. SA also maintained the physicochemical characteristics of fruit of different quality categories. Thus, SA may be an alternative to the commercial fungicides currently used against P. expansum.

  20. Is Salicylic Acid a Translocated Signal of Systemic Acquired Resistance in Tobacco?

    PubMed Central

    Shulaev, V.; Leon, J.; Raskin, I.

    1995-01-01

    Salicylic acid (SA) is a likely endogenous signal in the development of systemic acquired resistance (SAR) in some dicotyledonous plants. In tobacco mosaic virus (TMV)-resistant Xanthi-nc tobacco, SA levels increase systemically following the inoculation of a single leaf with TMV. To determine the extent to which systemic increases in SA result from SA export from the inoculated leaf, SA produced in TMV-inoculated or healthy leaves was noninvasively labeled with 18O2. Spatial and temporal distribution of 18O-SA indicated that most of the SA detected in the healthy tissues was synthesized in the inoculated leaf. No significant increase in the activity of benzoic acid 2-hydroxylase, the last enzyme involved in SA biosynthesis, was detected in upper uninoculated leaves, although the basal level of enzyme activity was relatively high. No increases in SA level, pathogenesis-related PR-1 gene expression, or TMV resistance in the upper uninoculated leaf were observed if the TMV-inoculated leaf was detached up to 60 hr after inoculation. Apart from the inoculated tissues, the highest increase in SA was observed in the leaf located directly above the inoculated leaf. The systemic SA increase observed during SAR may be explained by phloem transport of SA from the inoculation sites. PMID:12242358

  1. Necrotrophic pathogens use the salicylic acid signaling pathway to promote disease development in tomato.

    PubMed

    Rahman, Taha Abd El; Oirdi, Mohamed El; Gonzalez-Lamothe, Rocio; Bouarab, Kamal

    2012-12-01

    Plants use different immune pathways to combat pathogens. The activation of the jasmonic acid (JA)-signaling pathway is required for resistance against necrotrophic pathogens; however, to combat biotrophic pathogens, the plants activate mainly the salicylic acid (SA)-signaling pathway. SA can antagonize JA signaling and vice versa. NPR1 (noninducible pathogenesis-related 1) is considered a master regulator of SA signaling. NPR1 interacts with TGA transcription factors, ultimately leading to the activation of SA-dependent responses. SA has been shown to promote disease development caused by the necrotrophic pathogen Botrytis cinerea through NPR1, by suppressing the expression of two JA-dependent defense genes, proteinase inhibitors I and II. We show here that the transcription factor TGA1.a contributes to disease development caused by B. cinerea in tomato by suppressing the expression of proteinase inhibitors I and II. Finally, we present evidence that the SA-signaling pathway contributes to disease development caused by another necrotrophic pathogen, Alternaria solani, in tomato. Disease development promoted by SA through NPR1 requires the TGA1.a transcription factor. These data highlight how necrotrophs manipulate the SAsignaling pathway to promote their disease in tomato.

  2. Salicylic Acid and Calcium Treatments Improves Wheat Vigor, Lipids and Phenolics Under High Salinity.

    PubMed

    Yücel Candan, Nilgün; Heybet Elif, Haklı

    2016-12-01

    Seed vigor is a complex physiological trait required to ensure the rapid and uniform emergence of plants in the field under different environmental conditions. Therefore, salicylic acid (SA, 0.5 mM) and calcium (Ca2+, 50 mM) priming were used as exogenous growth enhancers to stimulate wheat (Triticum durum Desf. cv. Yelken) seed vigor under high salinity. The main aim was to address whether priming of wheat with SA, Ca2+ and SA+Ca (SA, 0.5 mM + Ca2+, 50 mM; their combination) could bring about supplementary agronomic benefits particularly under stressful environments such as salinity. Exogenous application of SA or Ca2+ alone improved plant behavior in the presence of salinity stress. Nevertheless, the best results in terms of growth, seed vigor and total phenolic - flavonoids, chlorophyll - carotenoids contents and phenylalanine ammonia-lyase (PAL), ascorbic acide oxidase (AAO) activities and lipid peroxidation levels (LPO) were obtained in response to the combined SA+Ca treatment.

  3. Modulation of reactive oxygen species by salicylic acid in Arabidopsis seed germination under high salinity.

    PubMed

    Lee, Sangmin; Park, Chung-Mo

    2010-12-01

    Potential roles of salicylic acid (SA) on seed germination have been explored in many plant species. However, it is still controversial how SA regulates seed germination, mainly because the results have been somewhat variable, depending on plant genotypes used and experimental conditions employed. We found that SA promotes seed germination under high salinity in Arabidopsis. Seed germination of the sid2 mutant, which has a defect in SA biosynthesis, is hypersensitive to high salinity, but the inhibitory effects are reduced in the presence of physiological concentrations of SA. Abiotic stresses, including high salinity, impose oxidative stress on plants. Endogenous contents of H(2)O(2) are higher in the sid2 mutant seeds. However, exogenous application of SA reduces endogenous level of reactive oxygen species (ROS), indicating that SA is involved in plant responses to ROS-mediated damage under abiotic stress conditions. Gibberellic acid (GA), a plant hormone closely associated with seed germination, also reverses the inhibitory effects of high salinity on seed germination and seedling establishment. Under high salinity, GA stimulates SA biosynthesis by inducing the SID2 gene. Notably, SA also induces genes encoding GA biosynthetic enzymes. These observations indicate that SA promotes seed germination under high salinity by modulating antioxidant activity through signaling crosstalks with GA.

  4. Salicylic acid treatment of pea seeds induces its de novo synthesis.

    PubMed

    Szalai, Gabriella; Horgosi, Szabina; Soós, Vilmos; Majláth, Imre; Balázs, Ervin; Janda, Tibor

    2011-02-15

    Salicylic acid (SA), which is known as a signal molecule in the induction of defense mechanisms in plants, could be a promising compound for the reduction of stress sensitivity. The aim of the present work was to investigate the distribution of SA in young pea (Pisum sativum L.) seedlings grown from seeds soaked in (3)H-labeled SA solution before sowing, and to study the physiological changes induced by this seed treatment. The most pronounced changes in SA levels occurred in the epicotyl and the seeds. Radioactivity was detected only in the bound form of SA, the majority of which was localized in the seeds, and only a very low level of radioactivity was detected in the epicotyl. SA pre-treatment increased the expression of the chorismate synthase and isochorismate synthase genes in the epicotyl. Pre-soaking the seeds in SA increased the activities of some antioxidant enzymes, namely ascorbate peroxidase (EC 1.11.1.11) and guaiacol peroxidase (EC 1.11.1.7) and the level of ortho-hydroxycinnamic acid, but decreased the level of polyamines. These results suggest that the increased level of free and bound SA detected in plants growing from seeds soaked in SA solution before sowing is the product of de novo synthesis, rather than having been taken up and mobilized by the plants.

  5. [Effects of salicylic acid on sucrose metabolism of tomato seedlings under NaCl stress].

    PubMed

    Su, Yue; Li, Tian-Lai; Li, Nan; Yang, Feng-Jun; Lu, Shao-Wei

    2009-06-01

    A water culture experiment was conducted with the seedlings of tomato (Lycopersicon esculentum Mill.) cultivar Liaoyuanduoli to study the effects of salicylic acid (SA) on their sucrose metabolism under NaCl stress. The seedlings were treated with different concentrations (100, 300, and 500 mg x L(-1)) of SA, and the contents of sucrose, glucose, and fructose as well as the related enzyme activities of sucrose metabolism, including acid invertase (AI), neutral invertase (NI), sucrose phosphate synthase (SPS), and sucrose synthase (SS), in seedling leaves were determined. Under NaCl stress, SA could maintain or enhance the leaf fructose and glucose contents and the leaf AI, NI, SPS and SS activities, with the highest increment of fructose and glucose contents being 30.0% and 31.1% and that of AI, NI, SPS and SS activities being 24.7%, 27.9%, 22.0% and 24.5%, respectively, in comparing with no SA application, while had less effect on the leaf sucrose content, which suggested that SA could play a protective role in the NaCl-tolerance of tomato seedlings via enhancing the leaf invertase activity to increase leaf fructose and glucose contents. The best alleviating effect was observed at 500 mg x L(-1) of SA.

  6. A central role of abscisic acid in drought stress protection of Agrobacterium-induced tumors on Arabidopsis.

    PubMed

    Efetova, Marina; Zeier, Jürgen; Riederer, Markus; Lee, Chil-Woo; Stingl, Nadja; Mueller, Martin; Hartung, Wolfram; Hedrich, Rainer; Deeken, Rosalia

    2007-11-01

    Crown gall tumors induced by Agrobacterium tumefaciens represent a sink that has to be provided with nutrients and water by the host plant. The lack of an intact epidermis or cuticle results in uncontrolled loss of water. However, neither the tumor nor the host plant displays wilting. This phenomenon points to drought adaptation in both tumors and the crown gall host plant. To understand the underlying molecular mechanisms of protection against desiccation the gene expression pattern of Arabidopsis (Arabidopsis thaliana) tumors was integrated with the profile of stress metabolites: Arabidopsis tumors accumulated high amounts of abscisic acid (ABA), the ethylene precursor aminocyclopropyl carboxylic acid, osmoprotectants, and form a suberized periderm-like protective layer. Suberization of the outer tumor cell layers most likely is mediated by ABA since external application of ABA induced suberization of Arabidopsis roots. However, the expression level of the classical marker genes, known to respond to drought stress and/or ABA, was lower in tumors. Instead another set of drought and/or ABA-inducible genes was more highly transcribed. Elevated transcription of several ABA-dependent aquaporin genes might indicate that ABA controls the water balance of the tumor. The retarded tumor growth on abi and aba mutant plants underlined the importance of a tumor-specific ABA signaling pathway. Taken together, we propose that ABA is an important signal for protection of tumors against desiccation and thus supports tumor development.

  7. 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.

  8. The Roles of Ethylene, Auxin, Abscisic Acid, and Gibberellin in the Hyponastic Growth of Submerged Rumex palustris Petioles1

    PubMed Central

    Cox, Marjolein C.H.; Benschop, Joris J.; Vreeburg, Robert A.M.; Wagemaker, Cornelis A.M.; Moritz, Thomas; Peeters, Anton J.M.; Voesenek, Laurentius A.C.J.

    2004-01-01

    Rumex palustris responds to complete submergence with upward movement of the younger petioles. This so-called hyponastic response, in combination with stimulated petiole elongation, brings the leaf blade above the water surface and restores contact with the atmosphere. We made a detailed study of this differential growth process, encompassing the complete range of the known signal transduction pathway: from the cellular localization of differential growth, to the hormonal regulation, and the possible involvement of a cell wall loosening protein (expansin) as a downstream target. We show that hyponastic growth is caused by differential cell elongation across the petiole base, with cells on the abaxial (lower) surface elongating faster than cells on the adaxial (upper) surface. Pharmacological studies and endogenous hormone measurements revealed that ethylene, auxin, abscisic acid (ABA), and gibberellin regulate different and sometimes overlapping stages of hyponastic growth. Initiation of hyponastic growth and (maintenance of) the maximum petiole angle are regulated by ethylene, ABA, and auxin, whereas the speed of the response is influenced by ethylene, ABA, and gibberellin. We found that a submergence-induced differential redistribution of endogenous indole-3-acetic acid in the petiole base could play a role in maintenance of the response, but not in the onset of hyponastic growth. Since submergence does not induce a differential expression of expansins across the petiole base, it is unlikely that this cell wall loosening protein is the downstream target for the hormones that regulate the differential cell elongation leading to submergence-induced hyponastic growth in R. palustris. PMID:15466223

  9. 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.

  10. Abscisic Acid Antagonizes Ethylene Production through the ABI4-Mediated Transcriptional Repression of ACS4 and ACS8 in Arabidopsis.

    PubMed

    Dong, Zhijun; Yu, Yanwen; Li, Shenghui; Wang, Juan; Tang, Saijun; Huang, Rongfeng

    2016-01-04

    Increasing evidence has revealed that abscisic acid (ABA) negatively modulates ethylene biosynthesis, although the underlying mechanism remains unclear. To identify the factors involved, we conducted a screen for ABA-insensitive mutants with altered ethylene production in Arabidopsis. A dominant allele of ABI4, abi4-152, which produces a putative protein with a 16-amino-acid truncation at the C-terminus of ABI4, reduces ethylene production. By contrast, two recessive knockout alleles of ABI4, abi4-102 and abi4-103, result in increased ethylene evolution, indicating that ABI4 negatively regulates ethylene production. Further analyses showed that expression of the ethylene