WorldWideScience

Sample records for aba responsiveness after-ripening

  1. Physiological characteristics and related gene expression of after-ripening on seed dormancy release in rice.

    Science.gov (United States)

    Du, W; Cheng, J; Cheng, Y; Wang, L; He, Y; Wang, Z; Zhang, H

    2015-11-01

    After-ripening is a common method used for dormancy release in rice. In this study, the rice variety Jiucaiqing (Oryza sativa L. subsp. japonica) was used to determine dormancy release following different after-ripening times (1, 2 and 3 months). Germination speed, germination percentage and seedling emergence increased with after-ripening; more than 95% germination and 85% seedling emergence were observed following 1 month of after-ripening within 10 days of imbibition, compared with germination and 20% seedling emergence in freshly harvested seed. Hence, 3 months of after-ripening could be considered a suitable treatment period for rice dormancy release. Dormancy release by after-ripening is mainly correlated with a rapid decline in ABA content and increase in IAA content during imbibition. Subsequently, GA(1)/ABA, GA(7)/ABA, GA(12)/ABA, GA(20)/ABA and IAA/ABA ratios significantly increased, while GA(3)/ABA, GA(4)/ABA and GAs/IAA ratio significantly decreased in imbibed seeds following 3 months of after-ripening, thereby altering α-amylase activity during seed germination. Peak α-amylase activity occurred at an earlier germination stage in after-ripened seeds than in freshly harvested seeds. Expression of ABA, GA and IAA metabolism genes and dormancy-related genes was regulated by after-ripening time upon imbibition. Expression of OsCYP707A5, OsGA2ox1, OsGA2ox2, OsGA2ox3, OsILR1, OsGH3-2, qLTG3-1 and OsVP1 increased, while expression of Sdr4 decreased in imbibed seeds following 3 months of after-ripening. Dormancy release through after-ripening might be involved in weakening tissues covering the embryo via qLTG3-1 and decreased ABA signalling and sensitivity via Sdr4 and OsVP1. PMID:26205956

  2. Elevated CO2-Induced Responses in Stomata Require ABA and ABA Signaling.

    Science.gov (United States)

    Chater, Caspar; Peng, Kai; Movahedi, Mahsa; Dunn, Jessica A; Walker, Heather J; Liang, Yun-Kuan; McLachlan, Deirdre H; Casson, Stuart; Isner, Jean Charles; Wilson, Ian; Neill, Steven J; Hedrich, Rainer; Gray, Julie E; Hetherington, Alistair M

    2015-10-19

    An integral part of global environment change is an increase in the atmospheric concentration of CO2 ([CO2]) [1]. Increased [CO2] reduces leaf stomatal apertures and density of stomata that plays out as reductions in evapotranspiration [2-4]. Surprisingly, given the importance of transpiration to the control of terrestrial water fluxes [5] and plant nutrient acquisition [6], we know comparatively little about the molecular components involved in the intracellular signaling pathways by which [CO2] controls stomatal development and function [7]. Here, we report that elevated [CO2]-induced closure and reductions in stomatal density require the generation of reactive oxygen species (ROS), thereby adding a new common element to these signaling pathways. We also show that the PYR/RCAR family of ABA receptors [8, 9] and ABA itself are required in both responses. Using genetic approaches, we show that ABA in guard cells or their precursors is sufficient to mediate the [CO2]-induced stomatal density response. Taken together, our results suggest that stomatal responses to increased [CO2] operate through the intermediacy of ABA. In the case of [CO2]-induced reductions in stomatal aperture, this occurs by accessing the guard cell ABA signaling pathway. In both [CO2]-mediated responses, our data are consistent with a mechanism in which ABA increases the sensitivity of the system to [CO2] but could also be explained by requirement for a CO2-induced increase in ABA biosynthesis specifically in the guard cell lineage. Furthermore, the dependency of stomatal [CO2] signaling on ABA suggests that the ABA pathway is, in evolutionary terms, likely to be ancestral. PMID:26455301

  3. A role for ABA in the plants response to chitosan

    Directory of Open Access Journals (Sweden)

    Americo Rodrigues

    2014-06-01

    Full Text Available Chitosan is a biopolymer of glucosamine residue that can be produced by deacetylation of chitin present in seafood wastes such as shrimp or crab shell. Chitosan and its derivatives are nontoxic and biodegradable, and have been used in applications like cosmetics, medicine or agriculture. When used to enhance plant defenses, chitosan induces host defense responses in both monocotyledons and dicotyledons. These responses include lignification, chitinase and glucanase activation, phytoalexin biosynthesis, among others (El Hadrami et al., 2010. Reduction of plant leaves transpiration due to stomatal closure without affecting the photosynthetic rate or production yields has also been described in plants treated with chitosan. This effect was observed in different plants like bean (Phaseolus vulgaris(Khokon et al., 2010, pepper (Capsicum sp(Bittelli et al., 2001 or barley (Hordeum vulgare (Koers et al., 2011 among others. Abscisic acid (ABA plays a crucial role in the regulation of stomata aperture (Kim et al., 2010 but the role of this phytohormone in the chitosan induced stomatal closure is not clearly understood. Chitosan treatment of bean leaves triggers a 3 times increase in ABA content indicating an involvement of ABA in chitosan induced stomatal closure (Iriti et al., 2009. However, in Arabidopsis, aba2-2 mutants and wild type plants treated with an ABA biosynthesis inhibitor presented chitosan induced stomatal closure similar to wild type untreated plants suggesting that endogenous ABA is not required for this effect (Issak et al., 2013. The involvement of ABA in this process is also suggested by the observation that chitosan and ABA have convergent signaling components, like calcium and reactive oxygen species (Srivastava et al., 2009. The aim of this work is to better understand the role of ABA in chitosan induced stomatal closure, leading to a reduction of transpiration and concomitantly to higher water-use efficiency, using molecular and

  4. Arabidopsis PYL8 Plays an Important Role for ABA Signaling and Drought Stress Responses

    OpenAIRE

    Lim, Chae Woo; Baek, Woonhee; Han, Sang-Wook; Lee, Sung Chul

    2013-01-01

    Plants are frequently exposed to numerous environmental stresses such as dehydration and high salinity, and have developed elaborate mechanisms to counteract the deleterious effects of stress. The phytohormone abscisic acid (ABA) plays a critical role as an integrator of plant responses to water-limited condition to activate ABA signal transduction pathway. Although perception of ABA has been suggested to be important, the function of each ABA receptor remains elusive in dehydration condition...

  5. Arabidopsis PYL8 Plays an Important Role for ABA Signaling and Drought Stress Responses

    Directory of Open Access Journals (Sweden)

    Chae Woo Lim

    2013-12-01

    Full Text Available Plants are frequently exposed to numerous environmental stresses such as dehydration and high salinity, and have developed elaborate mechanisms to counteract the deleterious effects of stress. The phytohormone abscisic acid (ABA plays a critical role as an integrator of plant responses to water-limited condition to activate ABA signal transduction pathway. Although perception of ABA has been suggested to be important, the function of each ABA receptor remains elusive in dehydration condition. Here, we show that ABA receptor, pyrabactin resistance-like protein 8 (PYL8, functions in dehydration conditions. Transgenic plants overexpressing PYL8 exhibited hypersensitive phenotype to ABA in seed germination, seedling growth and establishment. We found that hypersensitivity to ABA of transgenic plants results in high degrees of stomatal closure in response to ABA leading to low transpiration rates and ultimately more vulnerable to drought than the wild-type plants. In addition, high expression of ABA maker genes also contributes to altered drought tolerance phenotype. Overall, this work emphasizes the importance of ABA signaling by ABA receptor in stomata during defense response to drought stress.

  6. Arabidopsis PYL8 Plays an Important Role for ABA Signaling and Drought Stress Responses.

    Science.gov (United States)

    Lim, Chae Woo; Baek, Woonhee; Han, Sang-Wook; Lee, Sung Chul

    2013-12-01

    Plants are frequently exposed to numerous environmental stresses such as dehydration and high salinity, and have developed elaborate mechanisms to counteract the deleterious effects of stress. The phytohormone abscisic acid (ABA) plays a critical role as an integrator of plant responses to water-limited condition to activate ABA signal transduction pathway. Although perception of ABA has been suggested to be important, the function of each ABA receptor remains elusive in dehydration condition. Here, we show that ABA receptor, pyrabactin resistance-like protein 8 (PYL8), functions in dehydration conditions. Transgenic plants overexpressing PYL8 exhibited hypersensitive phenotype to ABA in seed germination, seedling growth and establishment. We found that hypersensitivity to ABA of transgenic plants results in high degrees of stomatal closure in response to ABA leading to low transpiration rates and ultimately more vulnerable to drought than the wild-type plants. In addition, high expression of ABA maker genes also contributes to altered drought tolerance phenotype. Overall, this work emphasizes the importance of ABA signaling by ABA receptor in stomata during defense response to drought stress. PMID:25288979

  7. Physiological responses of pisum sativum plant to exogenous aba application under drought conditions

    International Nuclear Information System (INIS)

    This study was carried out to investigate the possibility of using foliar ABA application with different concentrations (50,100 and 150 meu g/L-1) in order to decrease the adverse effect of water-deficit stress. The main parameters of interest were; growth parameters; endogenous phytohormones, proline; pigments contents; number and shape of stomata; minerals concentrations; isozymes; and SDS -PAGE protein profile in Pisum sativum plant at 36 days under drought and ABA treatments. The results showed that ABA reduces the reduction in both fresh and dry weights shoot and root of Pisum induced by drought stress. Proline content was increased in response to drought and ABA treatments. Water-stress caused significant reduction in Chl. a, b, whereas application of ABA significantly increased in total chlorohpyll. Water stress significantly decreased IAA, GA concentrations and increased ABA level in leaves than these of the control. ABA treatment partially overcame the decrease in IAA and GA contents. Water stress and ABA increased the activity of (POD) and (ACP) enzymes in Pisum plants. Proteins profile of Pisum sativum in shoot revealed qualitative and quantitative changes, also appearance or disappearance of some bands. After 54 days the yield harvested and total carbohydrates and SDS -PAGE protein profile in seed were investigated. The data showed that total carbohydrates contents were significantly decreased in plant under drought and ABA partially alleviate the adverse effect of water-deficit stress. (author)

  8. Role of abscisic acid (aba) in modulating the responses of two apple rootstocks to drought stress

    International Nuclear Information System (INIS)

    Drought stress is considered as the main limiting factor for apple (Malus domestica L.) production in some semi-arid areas of China. In this study, we investigated the modulation role of abscisic acid (ABA) and fluridone (ABA synthesis inhibitor) on water relations and antioxidant enzyme system in 2-year-old seedlings of two apple rootstocks i.e. Malus sieversii (Ledeb.) Roem. (MS) and Malus hupehensis (Pamp.) Rehd. (MH). Drought stress induced ion leakage, accumulation of malondiadehyde (MDA) and decreases in leaf water potential and relative water content (RWC) in both rootstocks, which were significantly alleviated by exogenous ABA application. Drought stress also induced markedly increases in endogenous ABA content and activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and glutathione reductase (GR), to a greater magnitude in MS as compared to MH rootstock. Concentration of 100 mol/L and 50 mol/L ABA had the most positive effects on drought-stressed rootstocks of MS and MH, respectively. Spraying optimum exogenous ABA contributed to enhancement in most of the above antioxidant enzymes activities but reduction in content of MDA and maintained the appropriate leaf water potential and RWC in both rootstocks. Pretreatment with fluridone aggravated ion leakage and the accumulation of MDA in two apple rootstocks under drought stress, which was overcome by exogenous ABA application to some extent. In conclusion, the endogenous ABA was probably involved in the regulation of two apple rootstocks in responses to drought stress. (author)

  9. New ABA-hypersensitive Arabidopsis mutants are affected in loci mediating responses to water deficit and Dickeya dadantii infection.

    Directory of Open Access Journals (Sweden)

    Anne Plessis

    Full Text Available On water deficit, abscisic acid (ABA induces stomata closure to reduce water loss by transpiration. To identify Arabidopsis thaliana mutants which transpire less on drought, infrared thermal imaging of leaf temperature has been used to screen for suppressors of an ABA-deficient mutant (aba3-1 cold-leaf phenotype. Three novel mutants, called hot ABA-deficiency suppressor (has, have been identified with hot-leaf phenotypes in the absence of the aba3 mutation. The defective genes imparted no apparent modification to ABA production on water deficit, were inherited recessively and enhanced ABA responses indicating that the proteins encoded are negative regulators of ABA signalling. All three mutants showed ABA-hypersensitive stomata closure and inhibition of root elongation with little modification of growth and development in non-stressed conditions. The has2 mutant also exhibited increased germination inhibition by ABA, while ABA-inducible gene expression was not modified on dehydration, indicating the mutated gene affects early ABA-signalling responses that do not modify transcript levels. In contrast, weak ABA-hypersensitivity relative to mutant developmental phenotypes suggests that HAS3 regulates drought responses by both ABA-dependent and independent pathways. has1 mutant phenotypes were only apparent on stress or ABA treatments, and included reduced water loss on rapid dehydration. The HAS1 locus thus has the required characteristics for a targeted approach to improving resistance to water deficit. In contrast to has2, has1 exhibited only minor changes in susceptibility to Dickeya dadantii despite similar ABA-hypersensitivity, indicating that crosstalk between ABA responses to this pathogen and drought stress can occur through more than one point in the signalling pathway.

  10. An ABA down-regulated bHLH transcription repressor gene, bHLH129 regulates root elongation and ABA response when overexpressed in Arabidopsis

    Science.gov (United States)

    Tian, Hainan; Guo, Hongyan; Dai, Xuemei; Cheng, Yuxin; Zheng, Kaijie; Wang, Xiaoping; Wang, Shucai

    2015-01-01

    Plant hormone abscisic acid (ABA) plays a crucial role in modulating plant responses to environmental stresses. Basic helix-loop-helix (bHLH) transcription factors are one of the largest transcription factor families that regulate multiple aspects of plant growth and development, as well as of plant metabolism in Arabidopsis. Several bHLH transcription factors have been shown to be involved in the regulation of ABA signaling. We report here the characterization of bHLH129, a bHLH transcription factor in Arabidopsis. We found that the expression level of bHLH129 was reduced in response to exogenously applied ABA, and elevated in the ABA biosynthesis mutant aba1-5. Florescence observation of transgenic plants expressing bHLH129-GFP showed that bHLH129 was localized in the nucleus, and transient expression of bHLH129 in protoplasts inhibited reporter gene expression. When expressed in Arabidopsis under the control of the 35S promoter, bHLH129 promoted root elongation, and the transgenic plants were less sensitivity to ABA in root elongation assays. Quantitative RT-PCR results showed that ABA response of several genes involved in ABA signaling, including ABI1, SnRK2.2, SnRK2.3 and SnRK2.6 were altered in the transgenic plants overexpressing bHLH129. Taken together, our study suggests that bHLH129 is a transcription repressor that negatively regulates ABA response in Arabidopsis. PMID:26625868

  11. Is gene transcription involved in seed dry after-ripening?

    Directory of Open Access Journals (Sweden)

    Patrice Meimoun

    Full Text Available Orthodox seeds are living organisms that survive anhydrobiosis and may display dormancy, an inability to germinate at harvest. Seed germination potential can be acquired during a prolonged period of dry storage called after-ripening. The aim of this work was to determine if gene transcription is an underlying regulatory mechanism for dormancy alleviation during after-ripening. To identify changes in gene transcription strictly associated with the acquisition of germination potential but not with storage, we used seed storage at low relative humidity that maintains dormancy as control. Transcriptome profiling was performed using DNA microarray to compare change in gene transcript abundance between dormant (D, after-ripened non-dormant (ND and after-ripened dormant seeds (control, C. Quantitative real-time polymerase chain reaction (qPCR was used to confirm gene expression. Comparison between D and ND showed the differential expression of 115 probesets at cut-off values of two-fold change (p<0.05. Comparisons between both D and C with ND in transcript abundance showed that only 13 transcripts, among 115, could be specific to dormancy alleviation. qPCR confirms the expression pattern of these transcripts but without significant variation between conditions. Here we show that sunflower seed dormancy alleviation in the dry state is not related to regulated changes in gene expression.

  12. Azospirillum brasilense ameliorates the response of Arabidopsis thaliana to drought mainly via enhancement of ABA levels.

    Science.gov (United States)

    Cohen, Ana C; Bottini, Rubén; Pontin, Mariela; Berli, Federico J; Moreno, Daniela; Boccanlandro, Hernán; Travaglia, Claudia N; Piccoli, Patricia N

    2015-01-01

    Production of phytohormones is one of the main mechanisms to explain the beneficial effects of plant growth-promoting rhizobacteria (PGPR) such as Azospirillum sp. The PGPRs induce plant growth and development, and reduce stress susceptibility. However, little is known regarding the stress-related phytohormone abscisic acid (ABA) produced by bacteria. We investigated the effects of Azospirillum brasilense Sp 245 strain on Arabidopsis thaliana Col-0 and aba2-1 mutant plants, evaluating the morphophysiological and biochemical responses when watered and in drought. We used an in vitro-grown system to study changes in the root volume and architecture after inoculation with Azospirillum in Arabidopsis wild-type Col-0 and on the mutant aba2-1, during early growth. To examine Arabidopsis development and reproductive success as affected by the bacteria, ABA and drought, a pot experiment using Arabidopsis Col-0 plants was also carried out. Azospirillum brasilense augmented plant biomass, altered root architecture by increasing lateral roots number, stimulated photosynthetic and photoprotective pigments and retarded water loss in correlation with incremented ABA levels. As well, inoculation improved plants seed yield, plants survival, proline levels and relative leaf water content; it also decreased stomatal conductance, malondialdehyde and relative soil water content in plants submitted to drought. Arabidopsis inoculation with A. brasilense improved plants performance, especially in drought.

  13. Identification and Characterization of ABA-Responsive MicroRNAs in Rice.

    Science.gov (United States)

    Tian, Caijuan; Zuo, Zhangli; Qiu, Jin-Long

    2015-07-20

    MicroRNAs (miRNAs) are endogenous non-coding small RNAs that silence genes through mRNA degradation or translational inhibition. The phytohormone abscisic acid (ABA) is essential for plant development and adaptation to abiotic and biotic stresses. In Arabidopsis, miRNAs are implicated in ABA functions. However, ABA-responsive miRNAs have not been systematically studied in rice. Here high throughput sequencing of small RNAs revealed that 107 miRNAs were differentially expressed in the rice ABA deficient mutant, Osaba1. Of these, 13 were confirmed by stem-loop RT-PCR. Among them, miR1425-5P, miR169a, miR169n, miR390-5P, miR397a and miR397b were up-regulated, but miR162b reduced in expression in Osaba1. The targets of these 13 miRNAs were predicted and validated by gene expression profiling. Interestingly, the expression levels of these miRNAs and their targets were regulated by ABA. Cleavage sites were detected on 7 of the miRNA targets by 5'-Rapid Amplification of cDNA Ends (5'-RACE). Finally, miR162b and its target OsTRE1 were shown to affect rice resistance to drought stress, suggesting that miR162b increases resistance to drought by targeting OsTRE1. Our work provides important information for further characterization and functional analysis of ABA-responsive miRNAs in rice. PMID:26233894

  14. Regulation of salt and ABA responses by CIPK14, a calcium sensor interacting protein kinase in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Calcium and protein kinase serve as the common mediators to regulate plant responses to multiple stresses including salt and ABA stimulus. Here we reported a novel protein kinase (CIPK14) that regulated the responses to ABA treatment and salt stress in Arabidopsis. CIPK14 transcripts, capable been checked in roots, stems, leaves and flowers, were highly expressed in flowers and roots. CIPK14 was induced by ABA and salt treatments. The disruption of CIPK14 altered the transcriptional pattern of a gene marker line related to ABA and salt responses, and the results suggested that CIPK14 probably was responsible to the control of the salt and ABA responses. Comparing with wild types, the lines inserted with the T-DNA in which CIPK14 gene expression was knocked out were also more sensitive to ABA and salt stimulus, showing low germination rate and the less root elongation. While, when these conditioned seeds were treated with norflurazon, their germination percentages could recover to a certain extent. We also found that exogenous calcium could have an effect on the transcription of CIPK14 under ABA and salt treatments, and it seemed that calcium ion might work upstream CIPK14 to regulate the plant response to ABA and salt response.

  15. Regulation of salt and ABA responses by CIPK14, a calcium sensor interacting protein kinase in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    QIN YuZhi; LI Xu; GUO Ming; DENG KeQin; LIN dianZhong; TANG DongYing; GUO XinHong; LIU XuanMing

    2008-01-01

    Calcium and protein kinsse serve as the common mediators to regulate plant responses to multiple stresses including salt and ABA stimulus. Here we reported a novel protein kinase (CIPK14) that regulated the responses to ABA treatment and salt stress in Arabidopsis. CIPK14 transcripts, capable been checked in roots, stems, leaves and flowers, were highly expressed in flowers and roots. CIPK14 was induced by ABA and salt treatments. The disruption of CIPK14 altered the transcriptional pattern of a gene marker line related to ABA and salt responses, and the results suggested that CIPK14 probably was responsible to the control of the salt and ABA responses. Comparing with wild types, the lines inserted with the T-DNA in which CIPK14 gene expression was knocked out were also more sensitive to ABA and salt stimulus, showing low germination rate and the less root elongation. While, when these conditioned seeds were treated with norflurazon, their germination percentages could recover to a certain extent. We also found that exogenous calcium could have an effect on the transcription of CIPK14 under ABA end salt treatments, and it seemed that calcium ion might work upstream ClPK14 to regulate the plant response to ABA and salt response.

  16. Genetic Analysis of Physcomitrella patens Identifies ABSCISIC ACID NON-RESPONSIVE, a Regulator of ABA Responses Unique to Basal Land Plants and Required for Desiccation Tolerance[OPEN

    Science.gov (United States)

    Kamisugi, Yasuko; Trinh, Chi H.; Schmutz, Jeremy; Muchero, Wellington; Melkonian, Michael; Rothfels, Carl J.; Li, Fay-Wei; Larsson, Anders; Edwards, Thomas A.

    2016-01-01

    The anatomically simple plants that first colonized land must have acquired molecular and biochemical adaptations to drought stress. Abscisic acid (ABA) coordinates responses leading to desiccation tolerance in all land plants. We identified ABA nonresponsive mutants in the model bryophyte Physcomitrella patens and genotyped a segregating population to map and identify the ABA NON-RESPONSIVE (ANR) gene encoding a modular protein kinase comprising an N-terminal PAS domain, a central EDR domain, and a C-terminal MAPKKK-like domain. anr mutants fail to accumulate dehydration tolerance-associated gene products in response to drought, ABA, or osmotic stress and do not acquire ABA-dependent desiccation tolerance. The crystal structure of the PAS domain, determined to 1.7-Å resolution, shows a conserved PAS-fold that dimerizes through a weak dimerization interface. Targeted mutagenesis of a conserved tryptophan residue within the PAS domain generates plants with ABA nonresponsive growth and strongly attenuated ABA-responsive gene expression, whereas deleting this domain retains a fully ABA-responsive phenotype. ANR orthologs are found in early-diverging land plant lineages and aquatic algae but are absent from more recently diverged vascular plants. We propose that ANR genes represent an ancestral adaptation that enabled drought stress survival of the first terrestrial colonizers but were lost during land plant evolution. PMID:27194706

  17. Transcription factor veracity: is GBF3 responsible for ABA-regulated expression of Arabidopsis Adh?

    Science.gov (United States)

    Lu, G; Paul, A L; McCarty, D R; Ferl, R J

    1996-01-01

    Assignment of particular transcription factors to specific roles in promoter elements can be problematic, especially in systems such as the G-box, where multiple factors of overlapping specificity exist. In the Arabidopsis alcohol dehydrogenase (Adh) promoter, the G-box regulates expression in response to cold and dehydration, presumably through the action of abscisic acid (ABA), and is bound by a nuclear protein complex in vivo during expression in cell cultures. In this report, we test the conventional wisdom of biochemical approaches used to identify DNA binding proteins and assess their specific interactions by using the G-box and a nearby half G-box element of the Arabidopsis Adh promoter as a model system. Typical in vitro assays demonstrated specific interaction of G-box factor 3 (GBF3) with both the G-box and the half G-box element. Dimethyl sulfate footprint analysis confirmed that the in vitro binding signature of GBF3 essentially matches the footprint signature detected in vivo at the G-box. Because RNA gel blot data indicated that GBF3 is itself induced by ABA, we might have concluded that GBF3 is indeed the GBF responsible in cell cultures for binding to the Adh G-box and is therefore responsible for ABA-regulated expression of Adh. Potential limitations of this conclusion are exposed by the fact that other GBFs bind the G-box with the same signature as GBF3, and subtle differences between in vivo and in vitro footprint signatures indicate that factors other than or in addition to GBF3 interact with the half G-box element. PMID:8672884

  18. Responses in gas exchange and water status between drought-tolerant and-susceptible soybean genotypes with ABA application

    Institute of Scientific and Technical Information of China (English)

    Md. Mokter Hossain; Hon-Ming Lam; Jianhua Zhang

    2015-01-01

    The purpose of this study was to investigate the physiological responses of drought-tolerant and drought-susceptible soybean genotypes to exogenous abscisic acid (ABA) application during progressive soil drying at seedling stages. Five-day old soybean seedlings were transplanted into PVC tubes filled with soil mixture. Seedlings were watered daily with similar water volumes until second trifoliate leaves emerged, and thereafter soil drying with or without exogenous ABA application was imposed. Half of the seedlings of each genotype were left for regular watering as control plants. Soil water status declined significantly over seven days of withholding water supply for both genotypes. Leaf expansion rate, stomatal conductance (gs), leaf water potential (ψw), and relative water content of leaves (%RWC) declined significantly under soil drying as well as soil drying with ABA application, compared to their values for well-watered soybean genotypes. However, a drought-tolerant genotype (C12) responded more rapidly than a drought-susceptible genotype (C08) after imposition of soil drying and soil drying with exogenous ABA. In addition, application of exogenous ABA to water-restricted soybeans resulted in higher%RWC andψw in the drought-tolerant than in the drought-susceptible genotype. Compared to the drought-susceptible genotype, the drought-tolerant genotype was more responsive to exogenous ABA application, resulting in a higher root-to-shoot ratio.

  19. Responses in gas exchange and water status between drought-tolerant and -susceptible soybean genotypes with ABA application

    Directory of Open Access Journals (Sweden)

    Md. Mokter Hossain

    2015-12-01

    Full Text Available The purpose of this study was to investigate the physiological responses of drought-tolerant and drought-susceptible soybean genotypes to exogenous abscisic acid (ABA application during progressive soil drying at seedling stages. Five-day old soybean seedlings were transplanted into PVC tubes filled with soil mixture. Seedlings were watered daily with similar water volumes until second trifoliate leaves emerged, and thereafter soil drying with or without exogenous ABA application was imposed. Half of the seedlings of each genotype were left for regular watering as control plants. Soil water status declined significantly over seven days of withholding water supply for both genotypes. Leaf expansion rate, stomatal conductance (gs, leaf water potential (ψw, and relative water content of leaves (%RWC declined significantly under soil drying as well as soil drying with ABA application, compared to their values for well-watered soybean genotypes. However, a drought-tolerant genotype (C12 responded more rapidly than a drought-susceptible genotype (C08 after imposition of soil drying and soil drying with exogenous ABA. In addition, application of exogenous ABA to water-restricted soybeans resulted in higher %RWC and ψw in the drought-tolerant than in the drought-susceptible genotype. Compared to the drought-susceptible genotype, the drought-tolerant genotype was more responsive to exogenous ABA application, resulting in a higher root-to-shoot ratio.

  20. A Dual-Function Transcription Factor, AtYY1, Is a Novel Negative Regulator of the Arabidopsis ABA Response Network.

    Science.gov (United States)

    Li, Tian; Wu, Xiu-Yun; Li, Hui; Song, Jian-Hui; Liu, Jin-Yuan

    2016-05-01

    Abscisic acid (ABA) plays crucial roles in plant growth and development, as well as in response to various environmental stresses. To date, many regulatory genes involved in the ABA response network have been identified; however, their roles have remained to be fully elucidated. In this study, we identified AtYY1, an Arabidopsis homolog of the mammalian C2H2 zinc-finger transcription factor Yin Yang 1 (YY1), as a novel negative regulator of the ABA response. AtYY1 is a dual-function transcription factor with both repression and activation domains. The expression of AtYY1 was induced by ABA and stress conditions including high salt and dehydration. The yy1 mutant was more sensitive to ABA and NaCl than the wild-type, while overexpressing AtYY1 plants were less sensitive. AtYY1 loss also enhanced ABA-induced stomatal closing and drought resistance. Moreover, AtYY1 can bind the ABA REPRESSOR1 (ABR1) promoter and directly upregulate ABR1 expression, as well as negatively regulate ABA- and salt-responsive gene expression. Additional analysis indicated that ABA INSENSITIVE4 (ABI4) might positively regulate AtYY1 expression and that ABR1 can antagonize this regulation. Our findings provide direct evidence that AtYY1 is a novel negative regulator of the ABA response network and that the ABI4-AtYY1-ABR1 regulatory pathway may fine-tune ABA-responsive gene expression in Arabidopsis. PMID:26961720

  1. After-ripening induced transcriptional changes of hormonal genes in wheat seeds: the cases of brassinosteroids, ethylene, cytokinin and salicylic acid.

    Directory of Open Access Journals (Sweden)

    Vijaya R Chitnis

    Full Text Available Maintenance and release of seed dormancy is regulated by plant hormones; their levels and seed sensitivity being the critical factors. This study reports transcriptional regulation of brassinosteroids (BR, ethylene (ET, cytokinin (CK and salicylic acid (SA related wheat genes by after-ripening, a period of dry storage that decays dormancy. Changes in the expression of hormonal genes due to seed after-ripening did not occur in the anhydrobiotic state but rather in the hydrated state. After-ripening induced dormancy decay appears to be associated with imbibition mediated increase in the synthesis and signalling of BR, via transcriptional activation of de-etiolated2, dwarf4 and brassinosteroid signaling kinase, and repression of brassinosteroid insensitive 2. Our analysis is also suggestive of the significance of increased ET production, as reflected by enhanced transcription of 1-aminocyclopropane-1-carboxylic acid oxidase in after-ripened seeds, and tight regulation of seed response to ET in regulating dormancy decay. Differential transcriptions of lonely guy, zeatin O-glucosyltransferases and cytokinin oxidases, and pseudo-response regulator between dormant and after-ripened seeds implicate CK in the regulation of seed dormancy in wheat. Our analysis also reflects the association of dormancy decay in wheat with seed SA level and NPR independent SA signaling that appear to be regulated transcriptionally by phenylalanine ammonia lyase, and whirly and suppressor of npr1 inducible1 genes, respectively. Co-expression clustering of the hormonal genes implies the significance of synergistic and antagonistic interaction between the different plant hormones in regulating wheat seed dormancy. These results contribute to further our understanding of the molecular features controlling seed dormancy in wheat.

  2. Responses of ABA and CTK to soil drought in leafless and leafy apple tree

    Institute of Scientific and Technical Information of China (English)

    李岩; 潘海春; 李德全

    2003-01-01

    The authors tested the contents of ABA (abscisic acid) , ZR (zeatin riboside), DHZR (dihydrozeatin riboside) and iPA (isopentenyl adenosine) in leafless and leafy apple trees ( Red Fufi/Malus micromalus Makino) during soil drought stress. ABA concentration in drought stressed leafless trees increased significantly compared to the controls. ABA both in roots and xylem rose steadily in the earlier drought stage, reaching a maximum of 1.46 ± 0.35 nmol g-1 FW and 117 nmol l-1 after the 8th day. Similar change patterns of ABA concentration was observed in the leafy trees during soil drought stress; ABA concentrations in roots and xylem sap increased and reached the maximum in the first three days; after 8th day , it decreased slightly, whereas leaf ABA concentration increased steadily in drought stressed plants throughout the duration of the experiment.Between drought stressed and control trees, no significant differences were observed in concentration of ZR and DHZR in both leafless and leafy trees ; whereas iPA concentration of the drought stressed leafless and leafy plants decreased markedly in the later stage of drought. These results showed that endogenous ABA originated mainly from the roots in the earlier drought stage, and mainly from the leaves in the later drought stage. Total CTK showed no reduction in the earlier drought stage and decreased in the later drought stage.

  3. Responses of ABA and CTK to soil drought in leafless and leafy apple tree

    Institute of Scientific and Technical Information of China (English)

    李岩; 潘海春; 李德全

    2003-01-01

    The authors tested the contents of ABA (abscisic acid), ZR (zeatin riboside), DHZR (dihydrozeatin riboside) and iPA (isopentenyl adenosine) in leafless and leafy apple trees (Red Fuji/Malus micromalus Makino) during soil drought stress. ABA concentration in drought stressed leafless trees increased significantly compared to the controls. ABA both in roots and xylem rose steadily in the earlier drought stage, reaching a maximum of 1.46±0.35 nmol g\\+-1FW and 117 nmol l\\+-1 after the 8th day. Similar change patterns of ABA concentration was observed in the leafy trees during soil drought stress; ABA concentrations in roots and xylem sap increased and reached the maximum in the first three days; after 8th day , it decreased slightly, whereas leaf ABA concentration increased steadily in drought stressed plants throughout the duration of the experiment. Between drought stressed and control trees, no significant differences were observed in concentration of ZR and DHZR in both leafless and leafy trees; whereas iPA concentration of the drought stressed leafless and leafy plants decreased markedly in the later stage of drought. These results showed that endogenous ABA originated mainly from the roots in the earlier drought stage, and mainly from the leaves in the later drought stage. Total CTK showed no reduction in the earlier drought stage and decreased in the later drought stage.

  4. Isolation of ABA-responsive mutants in allohexaploid bread wheat (Triticum aestivum L.): Drawing connections to grain dormancy, preharvest sprouting, and drought tolerance

    Science.gov (United States)

    This paper describes the isolation of Wheat ABA-responsive mutants (Warm) in Chinese spring background of allohexaploid Triticum aestivum. The plant hormone abscisic acid (ABA) is required for the induction of seed dormancy, the induction of stomatal closure and drought tolerance, and is associated...

  5. A G-protein β subunit, AGB1, negatively regulates the ABA response and drought tolerance by down-regulating AtMPK6-related pathway in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Dong-bei Xu

    Full Text Available Heterotrimeric G-proteins are versatile regulators involved in diverse cellular processes in eukaryotes. In plants, the function of G-proteins is primarily associated with ABA signaling. However, the downstream effectors and the molecular mechanisms in the ABA pathway remain largely unknown. In this study, an AGB1 mutant (agb1-2 was found to show enhanced drought tolerance, indicating that AGB1 might negatively regulate drought tolerance in Arabidopsis. Data showed that AGB1 interacted with protein kinase AtMPK6 that was previously shown to phosphorylate AtVIP1, a transcription factor responding to ABA signaling. Our study found that transcript levels of three ABA responsive genes, AtMPK6, AtVIP1 and AtMYB44 (downstream gene of AtVIP1, were significantly up-regulated in agb1-2 lines after ABA or drought treatments. Other ABA-responsive and drought-inducible genes, such as RD29A (downstream gene of AtMYB44, were also up-regulated in agb1-2 lines. Furthermore, overexpression of AtVIP1 resulted in hypersensitivity to ABA at seed germination and seedling stages, and significantly enhanced drought tolerance in transgenic plants. These results suggest that AGB1 was involved in the ABA signaling pathway and drought tolerance in Arabidopsis through down-regulating the AtMPK6, AtVIP1 and AtMYB44 cascade.

  6. Chelator profiling in Deschampsia cespitosa (L.) Beauv. Reveals a Ni reaction, which is distinct from the ABA and cytokinin associated response to Cd.

    Science.gov (United States)

    Hayward, Allison R; Coates, Kahlan E; Galer, Amy L; Hutchinson, Thomas C; Emery, R J Neil

    2013-03-01

    Plant hormones, including abscisic acid (ABA) and cytokinins (CKs), fluctuate as a result of excess metal exposure. Changes in hormonal concentration regulate plant growth and may also signal activation of metal chelators. The grass Deschampsia cespitosa was dosed with either Ni or Cd or pulsed with exogenous ABA. The roots were analyzed for ABA and CKs and for multiple potential metal chelators including: amino acids, nicotianamine (NA), and phytochelatins (PCs). They were quantified after 3 h and after 7 days, using LC-ESI MS/MS. The Ni treatment caused no measurable change in ABA or CK concentration; however, an increase in NA was documented. The Cd treatment resulted in a short-term ABA increase followed by a reduction in CKs and an increase in PC concentration. An exogenous ABA pulse in non-metal challenged plants induced changes in CKs and PCs that followed those of Cd treatment. Ni and Cd stress resulted in distinctly different detoxification responses. Since the reaction of CKs and putative metal chelators to Cd stress can be mimicked by an exogenous ABA pulse, it is suggested that ABA acts as a stress signal, resulting in reduced growth by way of decreased CK concentration and reduced metal toxicity through increased PC production.

  7. Involvement of rice histone deacetylase HDA705 in seed germination and in response to ABA and abiotic stresses.

    Science.gov (United States)

    Zhao, Jinhui; Li, Mingzhi; Gu, Dachuan; Liu, Xuncheng; Zhang, Jianxia; Wu, Kunlin; Zhang, Xinhua; Teixeira da Silva, Jaime A; Duan, Jun

    2016-02-01

    Histone acetylation and deacetylation play crucial roles in the modification of chromatin structure and regulation of gene expression in eukaryotes. Histone acetyltransferases (HATs) and histone deacetylases (HDACs) assist to maintain the balance of chromatin acetylation status. Previous studies showed that plant HDACs are key regulators involved in response to development and stresses. In this study, we examined the expression pattern and function of HDA705, a member of the RPD3/HDA1-type HDAC in rice. Overexpression of HDA705 in rice decreased ABA and salt stress resistance during seed germination. Delayed seed germination of HDA705 overexpression lines was associated with down-regulated expression of GA biosynthetic genes and up-regulation of ABA biosynthetic genes. Moreover, overexpression of HDA705 in rice enhanced osmotic stress resistance during the seedling stage. Our findings demonstrate that HDA705 may play a role in regulating seed germination and the response to abiotic stresses in rice. PMID:26772883

  8. New ABA-Hypersensitive Arabidopsis Mutants Are Affected in Loci Mediating Responses to Water Deficit and Dickeya dadantii Infection

    OpenAIRE

    Anne Plessis; Raphaël Cournol; Delphine Effroy; Viridiana Silva Pérez; Lucy Botran; Yvan Kraepiel; Anne Frey; Bruno Sotta; Gabriel Cornic; Jeffrey Leung; Jérôme Giraudat; Annie Marion-Poll; North, Helen M.

    2011-01-01

    On water deficit, abscisic acid (ABA) induces stomata closure to reduce water loss by transpiration. To identify Arabidopsis thaliana mutants which transpire less on drought, infrared thermal imaging of leaf temperature has been used to screen for suppressors of an ABA-deficient mutant (aba3-1) cold-leaf phenotype. Three novel mutants, called hot ABA-deficiency suppressor (has), have been identified with hot-leaf phenotypes in the absence of the aba3 mutation. The defective genes imparted no ...

  9. The Arabidopsis a zinc finger domain protein ARS1 is essential for seed germination and ROS homeostasis in response to ABA and oxidative stress

    Directory of Open Access Journals (Sweden)

    Dongwon eBaek

    2015-11-01

    Full Text Available The phytohormone abscisic acid (ABA induces accumulation of reactive oxygen species (ROS, which can disrupt seed dormancy and plant development. Here, we report the isolation and characterization of an Arabidopsis thaliana mutant called ars1 (aba and ros sensitive 1 that showed hypersensitivity to ABA during seed germination and to methyl viologen (MV at the seedling stage. ARS1 encodes a nuclear protein with one zinc finger domain, two nuclear localization signal (NLS domains, and one nuclear export signal (NES. The ars1 mutants showed reduced expression of a gene for superoxide dismutase (CSD3 and enhanced accumulation of ROS after ABA treatment. Transient expression of ARS1 in Arabidopsis protoplasts strongly suppressed ABA-mediated ROS production. Interestingly, nuclear-localized ARS1 translocated to the cytoplasm in response to treatment with ABA, H2O2, or MV. Taken together, these results suggest that ARS1 modulates seed germination and ROS homeostasis in response to ABA and oxidative stress in plants.

  10. Accumulation of dehydrin-like proteins in the mitochondria of cereals in response to cold, freezing, drought and ABA treatment

    Directory of Open Access Journals (Sweden)

    Vladimirova Svetlana V

    2002-06-01

    Full Text Available Abstract Background Dehydrins are known as Group II late embryogenesis abundant proteins. Their high hydrophilicity and thermostability suggest that they may be structure stabilizers with detergent and chaperone-like properties. They are localised in the nucleus, cytoplasm, and plasma membrane. We have recently found putative dehydrins in the mitochondria of some cereals in response to cold. It is not known whether dehydrin-like proteins accumulate in plant mitochondria in response to stimuli other than cold stress. Results We have found five putative dehydrins in the mitochondria of winter wheat, rye and maize seedlings. Two of these polypeptides had the same molecular masses in all three species (63 and 52 kD and were thermostable. Drought, freezing, cold, and exogenous ABA treatment led to higher accumulation of dehydrin-like protein (dlp 63 kD in the rye and wheat mitochondria. Protein 52 kD was induced by cold adaptation and ABA. Some accumulation of these proteins in the maize mitochondria was found after cold exposition only. The other three proteins appeared to be heat-sensitive and were either slightly induced or not induced at all by all treatments used. Conclusions We have found that, not only cold, but also drought, freezing and exogenous ABA treatment result in accumulation of the thermostable dehydrins in plant mitochondria. Most cryotolerant species such as wheat and rye accumulate more heat-stable dehydrins than cryosensitive species such as maize. It has been supposed that their function is to stabilize proteins in the membrane or in the matrix. Heat-sensitive putative dehydrins probably are not involved in the stress reaction and adaptation of plants.

  11. Identification and functional characterization of the pepper CaDRT1 gene involved in the ABA-mediated drought stress response.

    Science.gov (United States)

    Baek, Woonhee; Lim, Sohee; Lee, Sung Chul

    2016-05-01

    Plants are constantly challenged by various environmental stresses, including high salinity and drought, and they have evolved defense mechanisms to counteract the deleterious effects of these stresses. The plant hormone abscisic acid (ABA) regulates plant growth and developmental processes and mediates abiotic stress responses. Here, we identified the Capsicum annuum DRought Tolerance 1 (CaDRT1) gene from pepper leaves treated with ABA. CaDRT1 was strongly expressed in pepper leaves in response to environmental stresses and after ABA treatment, suggesting that the CaDRT1 protein functions in the abiotic stress response. Knockdown expression of CaDRT1 via virus-induced gene silencing resulted in a high level of drought susceptibility, and this was characterized by increased transpirational water loss via decreased stomatal closure. CaDRT1-overexpressing (OX) Arabidopsis plants exhibited an ABA-hypersensitive phenotype during the germinative, seedling, and adult stages. Additionally, these CaDRT1-OX plants exhibited a drought-tolerant phenotype characterized by low levels of transpirational water loss, high leaf temperatures, increased stomatal closure, and enhanced expression levels of drought-responsive genes. Taken together, our results suggest that CaDRT1 is a positive regulator of the ABA-mediated drought stress response. PMID:26869261

  12. Inspection of the Grapevine BURP Superfamily Highlights an Expansion of RD22 Genes with Distinctive Expression Features in Berry Development and ABA-Mediated Stress Responses

    OpenAIRE

    Matus, José Tomás; Aquea, Felipe; Espinoza, Carmen; Vega, Andrea; Cavallini, Erika; Santo, Silvia Dal; Cañón, Paola; de la Guardia, Amparo Rodríguez-Hoces; Serrano, Jennifer; Tornielli, Giovanni Battista; Arce-Johnson, Patricio

    2014-01-01

    The RESPONSIVE TO DEHYDRATION 22 (RD22) gene is a molecular link between abscisic acid (ABA) signalling and abiotic stress responses. Its expression has been used as a reliable ABA early response marker. In Arabidopsis, the single copy RD22 gene possesses a BURP domain also located at the C-terminus of USP embryonic proteins and the beta subunit of polygalacturonases. In grapevine, a RD22 gene has been identified but putative paralogs are also found in the grape genome, possibly forming a lar...

  13. Pepper protein phosphatase type 2C, CaADIP1 and its interacting partner CaRLP1 antagonistically regulate ABA signalling and drought response.

    Science.gov (United States)

    Lim, Chae Woo; Lee, Sung Chul

    2016-07-01

    Abscisic acid (ABA) is a key phytohormone that regulates plant growth and developmental processes, including seed germination and stomatal closing. Here, we report the identification and functional characterization of a novel type 2C protein phosphatase, CaADIP1 (Capsicum annuum ABA and Drought-Induced Protein phosphatase 1). The expression of CaADIP1 was induced in pepper leaves by ABA, drought and NaCl treatments. Arabidopsis plants overexpressing CaADIP1 (CaADIP1-OX) exhibited an ABA-hyposensitive and drought-susceptible phenotype. We used a yeast two-hybrid screening assay to identify CaRLP1 (Capsicum annuum RCAR-Like Protein 1), which interacts with CaADIP1 in the cytoplasm and nucleus. In contrast to CaADIP1-OX plants, CaRLP1-OX plants displayed an ABA-hypersensitive and drought-tolerant phenotype, which was characterized by low levels of transpirational water loss and increased expression of stress-responsive genes relative to those of wild-type plants. In CaADIP1-OX/CaRLP1-OX double transgenic plants, ectopic expression of the CaRLP1 gene led to strong suppression of CaADIP1-induced ABA hyposensitivity during the germinative and post-germinative stages, indicating that CaADIP1 and CaRLP1 act in the same signalling pathway and CaADIP1 functions downstream of CaRLP1. Our results indicate that CaADIP1 and its interacting partner CaRLP1 antagonistically regulate the ABA-dependent defense signalling response to drought stress. PMID:26825039

  14. Arabidopsis Tóxicos en Levadura 78 (AtATL78) mediates ABA-dependent ROS signaling in response to drought stress.

    Science.gov (United States)

    Suh, Ji Yeon; Kim, Soo Jin; Oh, Tae Rin; Cho, Seok Keun; Yang, Seong Wook; Kim, Woo Taek

    2016-01-01

    Plants have developed a variety of complicated responses to cope with drought, one of the most challenging environmental stresses. As a quick response, plants rapidly inhibit stomatal opening under the control of abscisic acid (ABA) signaling pathway, in order to preserve water. Here, we report that Arabidopsis Tóxicos en Levadura (ATL), a RING-type E3 ubiquitin ligase, mediates the ABA-dependent stomatal closure. In contrast to wild-type plants, the stomatal closure was fully impaired in atatl78 mutant plants even in the presence of exogenous ABA and reactive oxygen species (ROS). Besides, under high concentrations of Ca(2+), a down-stream signaling molecule of ABA signaling pathway, atatl78 mutant plants successfully closed the pores. Furthermore, AtATL78 protein indirectly associated with catalases and the deficiency of AtATL78 led the reduction of catalase activity and H2O2, implying the function of AtATL78 in the modulation of ROS activity. Based on these results, we suggest that AtATL78 possibly plays a role in promoting ROS-mediated ABA signaling pathway during drought stress. PMID:26612255

  15. Alkaline-stress response in Glycine soja leaf identifies specific transcription factors and ABA-mediated signaling factors.

    Science.gov (United States)

    Ge, Ying; Li, Yong; Lv, De-Kang; Bai, Xi; Ji, Wei; Cai, Hua; Wang, Ao-Xue; Zhu, Yan-Ming

    2011-06-01

    Transcriptome of Glycine soja leaf tissue during a detailed time course formed a foundation for examining transcriptional processes during NaHCO(3) stress treatment. Of a total of 2,310 detected differentially expressed genes, 1,664 genes were upregulated and 1,704 genes were downregulated at various time points. The number of stress-regulated genes increased dramatically after a 6-h stress treatment. GO category gene enrichment analysis revealed that most of the differentially expressed genes were involved in cell structure, protein synthesis, energy, and secondary metabolism. Another enrichment test revealed that the response of G. soja to NaHCO(3) highlights specific transcription factors, such as the C2C2-CO-like, MYB-related, WRKY, GARP-G2-like, and ZIM families. Co-expressed genes were clustered into ten classes (P < 0.001). Intriguingly, one cluster of 188 genes displayed a unique expression pattern that increases at an early stage (0.5 and 3 h), followed by a decrease from 6 to 12 h. This group was enriched in regulation of transcription components, including AP2-EREBP, bHLH, MYB/MYB-related, C2C2-CO-like, C2C2-DOF, C2C2, C3H, and GARP-G2-like transcription factors. Analysis of the 1-kb upstream regions of transcripts displaying similar changes in abundance identified 19 conserved motifs, potential binding sites for transcription factors. The appearance of ABA-responsive elements in the upstream of co-expression genes reveals that ABA-mediated signaling participates in the signal transduction in alkaline response.

  16. Protein tyrosine phosphatase is possibly involved in cellular signal transduction and the regulation of ABA accumulation in response to water deficit in Maize L. coleoptile

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Water deficit-induced ABA accumulation is an ideal model or "stimulus-response" system to investigate cellular stress signaling in plant cells, using such a model the cellular stress signaling triggered by water deficit was investigated in Maize L. coleoptile. Water deficit-induced ABA accumulation was sensitively blocked by NaVO3, a potent inhibitor both to plasma membrane H+-ATPase (PM-H+- ATPase) and protein tyrosine phosphatase (PTPase). However, while PM- H+-ATPase activity was unaffected under water deficit and PM- H+-ATPase activator did not induce an ABA accumulation instead of water deficit, water deficit induced an increase in the protein phosphatase activity, and furthermore, ABA accumulation was inhibited by PAO, a specific inhibitor of PTPase. These results indicate that protein phosphtases may be involved in the cellular signaling in response to water deficit. Further studies identified at least four species of protein phosphtase as assayed by using pNPP as substrate, among which one component was especially sensitive to NaVO3. The NaVO3-sensitive enzyme was purified and finally showed a protein band about 66 kD on SDS/PAGE. The purified enzyme showed a great activity to some specific PTPase substrates at pH 6.0. In addition to NaVO3, the enzyme was also sensitive to some other PTPase inhibitors such as Zn2+ and MO33+, but not to Ca2+ and Mg2+, indicating that it might be a protein tyrosine phosphatase. Interestingly, the purified enzyme could be deactivated by some reducing agent DTT, which was previously proved to be an inhibitor of water deficit-induced ABA accumulation. This result further proved that PTPase might be involved in the cellular signaling of ABA accumulation in response to water deficit.

  17. ABA Receptors: Past, Present and Future

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jianjun [Harvard University; Yang, Xiaohan [ORNL; Weston, David [ORNL; Chen, Jay [ORNL

    2011-01-01

    Abscisic acid (ABA) is the key plant stress hormone. Consistent with the earlier studies in support of the presence of both membrane- and cytoplasm-localized ABA receptors, recent studies have identified multiple ABA receptors located in various subcellular locations. These include a chloroplast envelope-localized receptor (the H subunit of Chloroplast Mg2+-chelatase/ABA Receptor), two plasma membrane-localized receptors (G-protein Coupled Receptor 2 and GPCR-type G proteins), and one cytosol/nucleus-localized Pyrabactin Resistant (PYR)/PYR-Like (PYL)/Regulatory Component of ABA Receptor 1 (RCAR). Although the downstream molecular events for most of the identified ABA receptors are currently unknown, one of them, PYR/PYL/RACR was found to directly bind and regulate the activity of a long-known central regulator of ABA signaling, the A-group protein phosphatase 2C (PP2C). Together with the Sucrose Non-fermentation Kinase Subfamily 2 (SnRK2s) protein kinases, a central signaling complex (ABA-PYR-PP2Cs-SnRK2s) that is responsible for ABA signal perception and transduction is supported by abundant genetic, physiological, biochemical and structural evidence. The identification of multiple ABA receptors has advanced our understanding of ABA signal perception and transduction while adding an extra layer of complexity.

  18. Calcineurin-B-Like Protein CBL9 Interacts with Target Kinase CIPK3 in the Regulation of ABA Response in Seed Germination

    Institute of Scientific and Technical Information of China (English)

    Girdhar K.Pandey; John J.Grant; Yong Hwa Cheong; Beom-Gi Kim; Le Gong Li; Sheng Luan

    2008-01-01

    Calcium plays a vital role as a second messenger in many signaling pathways in plants.The calcineurin B-like proteins (CBLs) represent a family of plant calcium-binding proteins that function in calcium signaling by interacting with their interacting protein kinases (CIPKs).In our previous study,we have reported a role for one of the CBLs (CBL9) and one of the CIPKs (CIPK3) in ABA signaling.Here,we have shown that CBL9 and CIPK3 physically and functionally interact with each other in regulating the ABA responses.The CBL9 and CIPK3 proteins interacted with each other in the yeast twohybrid system and when expressed in plant cells.The double mutant cbl9cipk3 showed the similar hypersensitive response to ABA as observed in single mutants (cbl9 or cipk3).The constitutively active form of CIPK3 genetically complemented the cbl9 mutant,indicating that CIPK3 function downstream of CBL9.Based on these findings,we conclude that CBL9 and CIPK3 act together in the same pathway for regulating ABA responses.

  19. Genome Wide Transcriptome Analysis reveals ABA mediated response in Arabidopsis during Gold (AuCl4- treatment

    Directory of Open Access Journals (Sweden)

    Devesh eShukla

    2014-11-01

    Full Text Available The unique physico-chemical properties of gold nanoparticles (AuNPs find manifold applications in diagnostics, medicine and catalysis. Chemical synthesis produces reactive AuNPs and generates hazardous by-products. Alternatively, plants can be utilized to produce AuNPs in an eco-friendly manner. To better control the biosynthesis of AuNPs, we need to first understand the detailed molecular response induced by AuCl4- In this study, we carried out global transcriptome analysis in root tissue of Arabidopsis grown for 12- hours in presence of gold solution (HAuCl4 using the novel unbiased Affymetrix exon array. Transcriptomics analysis revealed differential regulation of a total of 704 genes and 4900 exons. Of these, 492 and 212 genes were up- and downregulated, respectively. The validation of the expressed key genes, such as glutathione-S-transferases, auxin responsive genes, cytochrome P450 82C2, methyl transferases, transducin (G protein beta subunit, ERF transcription factor, ABC, and MATE transporters, was carried out through quantitative RT-PCR. These key genes demonstrated specific induction under AuCl4- treatment relative to other heavy metals, suggesting a unique plant-gold interaction. GO enrichment analysis reveals the upregulation of processes like oxidative stress, glutathione binding, metal binding, transport, and plant hormonal responses. Changes predicted in biochemical pathways indicated major modulation in glutathione mediated detoxification, flavones and derivatives, and plant hormone biosynthesis. Motif search analysis identified a highly significant enriched motif, ACGT, which is an abscisic acid responsive core element (ABRE, suggesting the possibility of ABA- mediated signaling. Identification of abscisic acid response element (ABRE points to the operation of a predominant signaling mechanism in response to AuCl4- exposure. Overall, this study presents a useful picture of plant-gold interaction with an identification of

  20. Genome wide transcriptome analysis reveals ABA mediated response in Arabidopsis during gold (AuCl(-) 4) treatment.

    Science.gov (United States)

    Shukla, Devesh; Krishnamurthy, Sneha; Sahi, Shivendra V

    2014-01-01

    The unique physico-chemical properties of gold nanoparticles (AuNPs) find manifold applications in diagnostics, medicine and catalysis. Chemical synthesis produces reactive AuNPs and generates hazardous by-products. Alternatively, plants can be utilized to produce AuNPs in an eco-friendly manner. To better control the biosynthesis of AuNPs, we need to first understand the detailed molecular response induced by AuCl(-) 4 In this study, we carried out global transcriptome analysis in root tissue of Arabidopsis grown for 12- h in presence of gold solution (HAuCl4) using the novel unbiased Affymetrix exon array. Transcriptomics analysis revealed differential regulation of a total of 704 genes and 4900 exons. Of these, 492 and 212 genes were up- and downregulated, respectively. The validation of the expressed key genes, such as glutathione-S-transferases, auxin responsive genes, cytochrome P450 82C2, methyl transferases, transducin (G protein beta subunit), ERF transcription factor, ABC, and MATE transporters, was carried out through quantitative RT-PCR. These key genes demonstrated specific induction under AuCl4(-) treatment relative to other heavy metals, suggesting a unique plant-gold interaction. GO enrichment analysis reveals the upregulation of processes like oxidative stress, glutathione binding, metal binding, transport, and plant hormonal responses. Changes predicted in biochemical pathways indicated major modulation in glutathione mediated detoxification, flavones and derivatives, and plant hormone biosynthesis. Motif search analysis identified a highly significant enriched motif, ACGT, which is an abscisic acid responsive core element (ABRE), suggesting the possibility of ABA- mediated signaling. Identification of abscisic acid response element (ABRE) points to the operation of a predominant signaling mechanism in response to AuCl(-) 4 exposure. Overall, this study presents a useful picture of plant-gold interaction with an identification of candidate genes

  1. Electrical signaling, stomatal conductance, ABA and Ethylene content in avocado trees in response to root hypoxia

    OpenAIRE

    Pilar M Gil; Gurovich, Luis; Schaffer, Bruce; García, Nicolás; Iturriaga, Rodrigo

    2009-01-01

    Avocado (Persea americana Mill.) trees are among the most sensitive of fruit tree species to root hypoxia as a result of flooded or poorly drained soil. Similar to drought stress, an early physiological response to root hypoxia in avocado is a reduction of stomatal conductance. It has been previously determined in avocado trees that an extracellular electrical signal between the base of stem and leaves is produced and related to reductions in stomatal conductance in response to drought stress...

  2. A Glycine soja ABA-responsive receptor-like cytoplasmic kinase, GsRLCK, positively controls plant tolerance to salt and drought stresses.

    Science.gov (United States)

    Sun, XiaoLi; Sun, Mingzhe; Luo, Xiao; Ding, XiaoDong; Ji, Wei; Cai, Hua; Bai, Xi; Liu, XiaoFei; Zhu, YanMing

    2013-06-01

    Receptor such as protein kinases are proposed to work as sensors to initiate signaling cascades in higher plants. However, little is known about the precise functions of receptor such as protein kinases in abiotic stress response in plants, especially in wild soybean. Here, we focused on characterization of the biological functions of a receptor-like cytoplasmic serine/threonine protein kinase gene, GsRLCK, which was previously identified as a putative salt-alkali stress-related gene from the transcriptome profiles of Glycine soja. Bioinformatic analysis showed that GsRLCK protein contained a conserved kinase catalytic domain and two transmembrane domains at the N-terminus, but no typical extracellular domain. Consistently, GsRLCK-eGFP fusion protein was observed on the plasma membrane, but eGFP alone was distributing throughout the cytoplasm in onion epidermal cells. Quantitative real-time PCR analysis revealed the induced expression of GsRLCK by ABA, salt, alkali, and drought stresses. However, the expression levels of GsRLCK seemed to be similar in different tissues, except soybean pod. Phenotypic assays demonstrated that GsRLCK overexpression decreased ABA sensitivity and altered expression levels of ABA-responsive genes. Furthermore, we also found that GsRLCK conferred increased tolerance to salt and drought stresses and increased expression levels of a handful of stress-responsive genes, when overexpressing in Arabidopsis. In a word, we gave exact evidence that GsRLCK was a novel receptor-like cytoplasmic protein kinase and played a crucial role in plant responses to ABA, salt, and drought stresses.

  3. A Key ABA Catabolic Gene, OsABA8ox3, Is Involved in Drought Stress Resistance in Rice

    OpenAIRE

    Shanlan Cai; Guobin Jiang; Nenghui Ye; Zhizhan Chu; Xuezhong Xu; Jianhua Zhang; Guohui Zhu

    2015-01-01

    Expressions of ABA biosynthesis genes and catabolism genes are generally co-regulated in plant development and responses to environmental stress. Up-regulation of OsNCED3 gene, a key gene in ABA biosynthesis, has been suggested as a way to enhance plant drought resistance but little is known for the role of ABA catabolic genes during drought stress. In this study, we found that OsABA8ox3 was the most highly expressed gene of the OsABA8ox family in rice leaves. Expression of OsABA8ox3 was prom...

  4. GhCAX3 gene, a novel Ca(2+/H(+ exchanger from cotton, confers regulation of cold response and ABA induced signal transduction.

    Directory of Open Access Journals (Sweden)

    Lian Xu

    Full Text Available As a second messenger, Ca(2+ plays a major role in cold induced transduction via stimulus-specific increases in [Ca(2+]cyt, which is called calcium signature. During this process, CAXs (Ca(2+/H(+ exchangers play critical role. For the first time, a putative Ca(2+/H(+ exchanger GhCAX3 gene from upland cotton (Gossypium hirsutum cv. 'YZ-1' was isolated and characterized. It was highly expressed in all tissues of cotton except roots and fibers. This gene may act as a regulator in cotton's response to abiotic stresses as it could be up-regulated by Ca(2+, NaCl, ABA and cold stress. Similar to other CAXs, it was proved that GhCAX3 also had Ca(2+ transport activity and the N-terminal regulatory region (NRR through yeast complementation assay. Over-expression of GhCAX3 in tobacco showed less sensitivity to ABA during seed germination and seedling stages, and the phenotypic difference between wild type (WT and transgenic plants was more significant when the NRR was truncated. Furthermore, GhCAX3 conferred cold tolerance in yeast as well as in tobacco seedlings based on physiological and molecular studies. However, transgenic plant seeds showed more sensitivity to cold stress compared to WT during seed germination, especially when expressed in N-terminal truncated version. Finally, the extent of sensitivity in transgenic lines was more severe than that in WT line under sodium tungstate treatment (an ABA repressor, indicating that ABA could alleviate cold sensitivity of GhCAX3 seeds, especially in short of its NRR. Meanwhile, we also found that overexpression of GhCAX3 could enhance some cold and ABA responsive marker genes. Taken together, these results suggested that GhCAX3 plays important roles in the cross-talk of ABA and cold signal transduction, and compared to full-length of GhCAX3, the absence of NRR could enhance the tolerance or sensitivity to cold stress, depending on seedling's developmental stages.

  5. Activation of dimeric ABA receptors elicits guard cell closure, ABA-regulated gene expression, and drought tolerance

    OpenAIRE

    Okamoto, Masanori; Peterson, Francis C.; Defries, Andrew; Park, Sang-Youl; Endo, Akira; Nambara, Eiji; Volkman, Brian F.; Cutler, Sean R.

    2013-01-01

    Abscisic acid (ABA) is an essential molecule in plant abiotic stress responses. It binds to soluble pyrabactin resistance1/PYR1-like/regulatory component of ABA receptor receptors and stabilizes them in a conformation that inhibits clade A type II C protein phosphatases; this leads to downstream SnRK2 kinase activation and numerous cellular outputs. We previously described the synthetic naphthalene sulfonamide ABA agonist pyrabactin, which activates seed ABA responses but fails to trigger sub...

  6. HOS3, an ELO-Like Gene, Inhibits Effects of ABA and Implicates a S-1-P/Ceramide Control System for Abiotic Stress Responses in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Tanya M. Quist; Irina Sokolchik; Huazhong Shi; Robert J. Joly; Ray A. Bressan; Albino Maggio; Meena Narsimhan; Xia Li

    2009-01-01

    A hyper-osmotically sensitive mutant of Arabidopsis thaliana, designated hos3-1 (high expression of osmotically responsive genes), was identified based on its hyper-luminescence of RD29A:LUC promoter fusion plants upon treatment with NaCI and ABA. These responses implicate the disrupted gene as a direct or indirect negative regulator of the RD29A stress-responsive pathway. By sequencing the flanking regions of the T-DNA borders, it was determined that the disrupted gene is at locus At4g36830, annotated as encoding a putative protein with high homology to CIG30 (ELO2/FEN1).CIG30 has been implicated in synthesis of very long chain fatty acids (VLCFA), which are essential precursors for sphingolipids and ceramides. Altered stress responses characteristic of ABA-hypersensitivity, including reduced root growth inhibition and reduced germination with ABA treatment and reduced water loss from leaves, were exhibited by allelic hos3-1 and hos3-2 mutants. The hos3-2 mutant is partially suppressed in its transcript abundance and is inherited as a recessive trait. Further, the HOS30RF under the control of the 35SCaMV promoter restored wild-type NaCI- and ABA-root growth sensitivity as well as RD29A:LUC luminescence in mutant plants. We also show here that the HOS3 wild-type gene functionally complements the sensitivity of elo2 and elo3 yeast mutants to monensin. Furthermore, both hos3-1 and hos3-2 alleles shared increased sensitivity to the herbicide Metolachlor, which inhibits acyl chain elongation in synthesis of VLCFA, and HOS3 functionally complemented both elo2 and elo3 and restored levels of VLCFA. Together, these data establish that HOS3 inhibits ABA-mediated stress responses and implicate the VLCFA pathway and products as control points for several aspects of abiotic stress signaling and responses. The results also provide support for a role of ceramide in the control of stomatal behavior.

  7. HD2C interacts with HDA6 and is involved in ABA and salt stress response in Arabidopsis

    OpenAIRE

    Luo, Ming; Wang, Yu-Yuan; Liu, Xuncheng; Yang, Songguang; Lu, Qing; Cui, Yuhai; Wu, Keqiang

    2012-01-01

    HD2 proteins are plant specific histone deacetylases. Four HD2 proteins, HD2A, HD2B, HD2C, and HD2D, have been identified in Arabidopsis. It was found that the expression of HD2A, HD2B, HD2C, and HD2D was repressed by ABA and NaCl. To investigate the function of HD2 proteins further, two HD2C T-DNA insertion lines of Arabidopsis, hd2c-1 and hd2c-3 were identified. Compared with wild-type plants, hd2c-1 and hd2c-3 plants displayed increased sensitivity to ABA and NaCl during germination and de...

  8. Dormant and after-Ripened Arabidopsis thaliana Seeds are Distinguished by Early Transcriptional Differences in the Imbibed State

    Science.gov (United States)

    Dekkers, Bas J. W.; Pearce, Simon P.; van Bolderen-Veldkamp, R. P. M.; Holdsworth, Michael J.; Bentsink, Leónie

    2016-01-01

    Seed dormancy is a genetically controlled block preventing the germination of imbibed seeds in favorable conditions. It requires a period of dry storage (after-ripening) or certain environmental conditions to be overcome. Dormancy is an important seed trait, which is under selective pressure, to control the seasonal timing of seed germination. Dormant and non-dormant (after-ripened) seeds are characterized by large sets of differentially expressed genes. However, little information is available concerning the temporal and spatial transcriptional changes during early stages of rehydration in dormant and non-dormant seeds. We employed genome-wide transcriptome analysis on seeds of the model plant Arabidopsis thaliana to investigate transcriptional changes in dry seeds upon rehydration. We analyzed gene expression of dormant and after-ripened seeds of the Cvi accession over four time points and two seed compartments (the embryo and surrounding single cell layer endosperm), during the first 24 h after sowing. This work provides a global view of gene expression changes in dormant and non-dormant seeds with temporal and spatial detail, and these may be visualized via a web accessible tool (http://www.wageningenseedlab.nl/resources). A large proportion of transcripts change similarly in both dormant and non-dormant seeds upon rehydration, however, the first differences in transcript abundances become visible shortly after the initiation of imbibition, indicating that changes induced by after-ripening are detected and responded to rapidly upon rehydration. We identified several gene expression profiles which contribute to differential gene expression between dormant and non-dormant samples. Genes with enhanced expression in the endosperm of dormant seeds were overrepresented for stress-related Gene Ontology categories, suggesting a protective role for the endosperm against biotic and abiotic stress to support persistence of the dormant seed in its environment. PMID

  9. Dormant and after-Ripened Arabidopsis thaliana Seeds are Distinguished by Early Transcriptional Differences in the Imbibed State.

    Science.gov (United States)

    Dekkers, Bas J W; Pearce, Simon P; van Bolderen-Veldkamp, R P M; Holdsworth, Michael J; Bentsink, Leónie

    2016-01-01

    Seed dormancy is a genetically controlled block preventing the germination of imbibed seeds in favorable conditions. It requires a period of dry storage (after-ripening) or certain environmental conditions to be overcome. Dormancy is an important seed trait, which is under selective pressure, to control the seasonal timing of seed germination. Dormant and non-dormant (after-ripened) seeds are characterized by large sets of differentially expressed genes. However, little information is available concerning the temporal and spatial transcriptional changes during early stages of rehydration in dormant and non-dormant seeds. We employed genome-wide transcriptome analysis on seeds of the model plant Arabidopsis thaliana to investigate transcriptional changes in dry seeds upon rehydration. We analyzed gene expression of dormant and after-ripened seeds of the Cvi accession over four time points and two seed compartments (the embryo and surrounding single cell layer endosperm), during the first 24 h after sowing. This work provides a global view of gene expression changes in dormant and non-dormant seeds with temporal and spatial detail, and these may be visualized via a web accessible tool (http://www.wageningenseedlab.nl/resources). A large proportion of transcripts change similarly in both dormant and non-dormant seeds upon rehydration, however, the first differences in transcript abundances become visible shortly after the initiation of imbibition, indicating that changes induced by after-ripening are detected and responded to rapidly upon rehydration. We identified several gene expression profiles which contribute to differential gene expression between dormant and non-dormant samples. Genes with enhanced expression in the endosperm of dormant seeds were overrepresented for stress-related Gene Ontology categories, suggesting a protective role for the endosperm against biotic and abiotic stress to support persistence of the dormant seed in its environment. PMID

  10. Inspection of the grapevine BURP superfamily highlights an expansion of RD22 genes with distinctive expression features in berry development and ABA-mediated stress responses.

    Directory of Open Access Journals (Sweden)

    José Tomás Matus

    Full Text Available The RESPONSIVE TO DEHYDRATION 22 (RD22 gene is a molecular link between abscisic acid (ABA signalling and abiotic stress responses. Its expression has been used as a reliable ABA early response marker. In Arabidopsis, the single copy RD22 gene possesses a BURP domain also located at the C-terminus of USP embryonic proteins and the beta subunit of polygalacturonases. In grapevine, a RD22 gene has been identified but putative paralogs are also found in the grape genome, possibly forming a large RD22 family in this species. In this work, we searched for annotations containing BURP domains in the Vitis vinifera genome. Nineteen proteins were defined by a comparative analysis between the two genome predictions and RNA-Seq data. These sequences were compared to other plant BURPs identified in previous genome surveys allowing us to reconceive group classifications based on phylogenetic relationships and protein motif occurrence. We observed a lineage-specific evolution of the RD22 family, with the biggest expansion in grapevine and poplar. In contrast, rice, sorghum and maize presented highly expanded monocot-specific groups. The Vitis RD22 group may have expanded from segmental duplications as most of its members are confined to a region in chromosome 4. The inspection of transcriptomic data revealed variable expression of BURP genes in vegetative and reproductive organs. Many genes were induced in specific tissues or by abiotic and biotic stresses. Three RD22 genes were further studied showing that they responded oppositely to ABA and to stress conditions. Our results show that the inclusion of RNA-Seq data is essential while describing gene families and improving gene annotations. Robust phylogenetic analyses including all BURP members from other sequenced species helped us redefine previous relationships that were erroneously established. This work provides additional evidence for RD22 genes serving as marker genes for different organs or stresses

  11. Inspection of the grapevine BURP superfamily highlights an expansion of RD22 genes with distinctive expression features in berry development and ABA-mediated stress responses.

    Science.gov (United States)

    Matus, José Tomás; Aquea, Felipe; Espinoza, Carmen; Vega, Andrea; Cavallini, Erika; Dal Santo, Silvia; Cañón, Paola; Rodríguez-Hoces de la Guardia, Amparo; Serrano, Jennifer; Tornielli, Giovanni Battista; Arce-Johnson, Patricio

    2014-01-01

    The RESPONSIVE TO DEHYDRATION 22 (RD22) gene is a molecular link between abscisic acid (ABA) signalling and abiotic stress responses. Its expression has been used as a reliable ABA early response marker. In Arabidopsis, the single copy RD22 gene possesses a BURP domain also located at the C-terminus of USP embryonic proteins and the beta subunit of polygalacturonases. In grapevine, a RD22 gene has been identified but putative paralogs are also found in the grape genome, possibly forming a large RD22 family in this species. In this work, we searched for annotations containing BURP domains in the Vitis vinifera genome. Nineteen proteins were defined by a comparative analysis between the two genome predictions and RNA-Seq data. These sequences were compared to other plant BURPs identified in previous genome surveys allowing us to reconceive group classifications based on phylogenetic relationships and protein motif occurrence. We observed a lineage-specific evolution of the RD22 family, with the biggest expansion in grapevine and poplar. In contrast, rice, sorghum and maize presented highly expanded monocot-specific groups. The Vitis RD22 group may have expanded from segmental duplications as most of its members are confined to a region in chromosome 4. The inspection of transcriptomic data revealed variable expression of BURP genes in vegetative and reproductive organs. Many genes were induced in specific tissues or by abiotic and biotic stresses. Three RD22 genes were further studied showing that they responded oppositely to ABA and to stress conditions. Our results show that the inclusion of RNA-Seq data is essential while describing gene families and improving gene annotations. Robust phylogenetic analyses including all BURP members from other sequenced species helped us redefine previous relationships that were erroneously established. This work provides additional evidence for RD22 genes serving as marker genes for different organs or stresses in grapevine. PMID

  12. Two Groups of Thellungiella salsuginea RAVs Exhibit Distinct Responses and Sensitivity to Salt and ABA in Transgenic Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Shaohui Yang

    Full Text Available Containing both AP2 domain and B3 domain, RAV (Related to ABI3/VP1 transcription factors are involved in diverse functions in higher plants. A total of eight TsRAV genes were isolated from the genome of Thellungiella salsuginea and could be divided into two groups (A- and B-group based on their sequence similarity. The mRNA abundance of all Thellungiella salsuginea TsRAVs followed a gradual decline during seed germination. In Thellungiella salsuginea seedling, transcripts of TsRAVs in the group A (A-TsRAVs were gradually and moderately reduced by salt treatment but rapidly and severely repressed by ABA treatment. In comparison, with a barely detectable constitutive expression, the transcriptional level of TsRAVs in the group B (B-TsRAVs exhibited a moderate induction in cotyledons when confronted with ABA. We then produced the "gain-of-function" transgenic Arabidopsis plants for each TsRAV gene and found that only 35S:A-TsRAVs showed weak growth retardation including reduced root elongation, suggesting their roles in negatively controlling plant growth. Under normal conditions, the germination process of all TsRAVs overexpressing transgenic seeds was inhibited with a stronger effect observed in 35S:A-TsRAVs seeds than in 35S:B-TsRAVs seeds. With the presence of NaCl, seed germination and seedling root elongation of all plants including wild type and 35S:TsRAVs plants were retarded and a more severe inhibition occurred to the 35S:A-TsRAV transgenic plants. ABA treatment only negatively affected the germination rates of 35S:A-TsRAV transgenic seeds but not those of 35S:B-TsRAV transgenic seeds. All 35S:TsRAVs transgenic plants showed a similar degree of reduction in root growth compared with untreated seedlings in the presence of ABA. Furthermore, the cotyledon greening/expansion was more severely inhibited 35S:A-TsRAVs than in 35S:B-TsRAVs seedlings. Upon water deficiency, with a wider opening of stomata, 35S:A-TsRAVs plants experienced a faster

  13. Physiological responses of potato (Solanum tuberosum L.) to partial root-zone drying: ABA signalling, leaf gas exchange, and water use efficiency.

    Science.gov (United States)

    Liu, Fulai; Shahnazari, Ali; Andersen, Mathias N; Jacobsen, Sven-Erik; Jensen, Christian R

    2006-01-01

    The physiological responses of potato (Solanum tuberosum L. cv. Folva) to partial root-zone drying (PRD) were investigated in potted plants in a greenhouse (GH) and in plants grown in the field under an automatic rain-out-shelter. In the GH, irrigation was applied daily to the whole root system (FI), or to one-half of the root system while the other half was dried, for 9 d. In the field, the plants were drip irrigated either to the whole root system near field capacity (FI) or using 70% water of FI to one side of the roots, and shifted to the other side every 5-10 d (PRD). PRD plants had a similar midday leaf water potential to that of FI, whereas in the GH their root water potential (Psi(r)) was significantly lowered after 5 d. Stomatal conductance (g(s)) was more sensitive to PRD than photosynthesis (A) particularly in the field, leading to greater intrinsic water use efficiency (WUE) (i.e. A/g(s)) in PRD than in FI plants on several days. In PRD, the xylem sap abscisic acid concentration ([ABA](xylem)) increased exponentially with decreasing Psi(r); and the relative [ABA](xylem) (PRD/FI) increased exponentially as the fraction of transpirable soil water (FTSW) in the drying side decreased. In the field, the leaf area index was slightly less in PRD than in FI treatment, while tuber biomass was similar for the two treatments. Compared with FI, PRD treatment saved 30% water and increased crop water use efficiency (WUE) by 59%. Restrictions on leaf area expansion and g(s) by PRD-induced ABA signals might have contributed to reduced water use and increased WUE.

  14. RNA-Seq and Gene Network Analysis Uncover Activation of an ABA-Dependent Signalosome During the Cork Oak Root Response to Drought.

    Science.gov (United States)

    Magalhães, Alexandre P; Verde, Nuno; Reis, Francisca; Martins, Inês; Costa, Daniela; Lino-Neto, Teresa; Castro, Pedro H; Tavares, Rui M; Azevedo, Herlânder

    2015-01-01

    Quercus suber (cork oak) is a West Mediterranean species of key economic interest, being extensively explored for its ability to generate cork. Like other Mediterranean plants, Q. suber is significantly threatened by climatic changes, imposing the need to quickly understand its physiological and molecular adaptability to drought stress imposition. In the present report, we uncovered the differential transcriptome of Q. suber roots exposed to long-term drought, using an RNA-Seq approach. 454-sequencing reads were used to de novo assemble a reference transcriptome, and mapping of reads allowed the identification of 546 differentially expressed unigenes. These were enriched in both effector genes (e.g., LEA, chaperones, transporters) as well as regulatory genes, including transcription factors (TFs) belonging to various different classes, and genes associated with protein turnover. To further extend functional characterization, we identified the orthologs of differentially expressed unigenes in the model species Arabidopsis thaliana, which then allowed us to perform in silico functional inference, including gene network analysis for protein function, protein subcellular localization and gene co-expression, and in silico enrichment analysis for TFs and cis-elements. Results indicated the existence of extensive transcriptional regulatory events, including activation of ABA-responsive genes and ABF-dependent signaling. We were then able to establish that a core ABA-signaling pathway involving PP2C-SnRK2-ABF components was induced in stressed Q. suber roots, identifying a key mechanism in this species' response to drought.

  15. RNA-Seq and gene network analysis uncover activation of an ABA-dependent signalosome during the cork oak root response to drought

    Directory of Open Access Journals (Sweden)

    Alexandre Papadopoulos Magalhães

    2016-01-01

    Full Text Available Quercus suber (cork oak is a West Mediterranean species of key economic interest, being extensively explored for its ability to generate cork. Like other Mediterranean plants, Q. suber is significantly threatened by climatic changes, imposing the need to quickly understand its physiological and molecular adaptability to drought stress imposition. In the present report, we uncovered the differential transcriptome of Q. suber roots exposed to long-term drought, using an RNA-Seq approach. 454 sequencing reads were used to de novo assemble a reference transcriptome, and mapping of reads allowed the identification of 546 differentially expressed unigenes. These were enriched in both effector genes (e.g. LEA, chaperones, transporters as well as regulatory genes, including transcription factors (TFs belonging to various different classes, and genes associated with protein turnover. To further extend functional characterization, we identified the orthologs of differentially expressed unigenes in the model species Arabidopsis thaliana, which then allowed us to perform in silico functional inference, including gene network analysis for protein function, protein subcellular localization and gene co-expression, and in silico enrichment analysis for TFs and cis-elements. Results indicated the existence of extensive transcriptional regulatory events, including activation of ABA-responsive genes and ABF-dependent signaling. We were then able to establish that all components of a core ABA-signaling pathway involving PP2C-SnRK2-ABF components was induced in stressed Q. suber roots, identifying a key mechanism in this species’ response to drought.

  16. Constitutive expression of the barley dehydrin gene aba2 enhances Arabidopsis germination in response to salt stress

    Directory of Open Access Journals (Sweden)

    Cristina Calestani

    2015-10-01

    Full Text Available Dehydrins (DHNs are a sub-family of the late embryogenesis abundant proteins generally induced during development of desiccation tolerance in seeds and water deficit or salinity stress in plants. Nevertheless, a detailed understanding of the DHNs function is still lacking. In this work we investigated the possible protective role during salt stress of a Dhn from Hordeum vulgare (L., aba2. The coding sequence of the aba2 gene was constitutively expressed in transgenic lines of Arabidopsis thaliana (L.. During salt stress conditions germination rate, cotyledon expansion and greening were greatly improved in the transgenic lines as compared to the wild type. Between 98 and 100% of the transgenic seeds germinated after two weeks in media containing up to 250 mM NaCl, and 90% after 22 days at 300 mM NaCl. In conditions of 200 mM NaCl 93% of the transgenic cotyledons had greened after two weeks, outperforming the wild type by 45%. Our study provides further evidence that DHNs have an important role in salt stress tolerance. The production of plants constitutively expressing DHNs could be an effective strategy to improve plant breeding programs.

  17. Tourism First for Aba

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A tourism market regulatory body has been established in the Aba Zangzu Qiangzu Autonomous Prefecture,which is located in the northwest of Sichuan Province and along the southeastern fringe of the Qinghai-Tibet Plateau.

  18. 拟南芥PKS5激酶磷酸化ABI5参与植物ABA响应%PKS5 Kinase is Involved in ABA Response through Phosphorylating ABI5 in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    赵菲佚; 焦成瑾; 陈荃; 王太术; 田春芳; 高雅梅

    2015-01-01

    植物激素脱落酸(abscisic acid, ABA)在植物生长、发育及环境胁迫中起着重要的作用。本研究发现拟南芥PKSes (SOS2-like protein kinases)蛋白激酶家族成员PKS5(SOS2-like protein kinase 5)参与植物ABA响应。PKS5功能获得性点突变体pks5-3与pks5-4表现出对ABA的敏感表型。在外源ABA处理下, pks5-3与pks5-4种子萌发率降低,幼苗生长矮小、黄化。体外磷酸化测试显示, PKS5特异磷酸化ABA响应元件ABI5(ABA-insensitive 5) N末端多肽(1~211 aa)。qRT-PCR分析表明pks5-3与pks5-4突变体中ABI5下游ABA响应基因RAB18(RESPONSIVE TO ABA18)与EM6(LATE EMBRYOGENESIS ABUNDANT 6)表达均发生改变。这些研究结果表明,拟南芥PKS5通过磷酸化ABI5的N末端参与植物ABA响应过程。%The phytohormone abscisic acid (ABA) plays an essential role in plant growth and development as well as abiotic stress responses. In this study, we found that PKS5 (SOS2-like protein kinase 5), a family mem-ber of PKSes (SOS2-like protein kinases), involved in ABA response inArabidopsis.PKS5 gain-of-function point mutantspks5-3andpks5-4 exhibited hypersensitive to ABA in the phenotypic test. Additionally, seed ger-minations ofpks5-3andpks5-4 decreased and seedlings of them showed stunted growth and leaf chlorotic symptoms under exogenous ABA treatment.In vitro phosphorylation assay indicated that PKS5 speciifcally phosphorylates the ABA-responsive component ABI5 (ABA-insensitive 5) N terminus fragment range from 1 to 211 amino acids. Moreover, the relative expression levels ofRAB18 andEM6, which are the downstream ABA-responsive genes of ABI5, signiifcantly altered inpks5-3andpks5-4 mutants compared with the wild-type plants by quantitative real-time PCR using gene-speciifc primers. Taken together, the results of this study revealed that PKS5 involves in ABA response via phosphorylating the N-terminus of ABI5 in Arabidopsis.

  19. A key ABA catabolic gene, OsABA8ox3, is involved in drought stress resistance in rice.

    Directory of Open Access Journals (Sweden)

    Shanlan Cai

    Full Text Available Expressions of ABA biosynthesis genes and catabolism genes are generally co-regulated in plant development and responses to environmental stress. Up-regulation of OsNCED3 gene, a key gene in ABA biosynthesis, has been suggested as a way to enhance plant drought resistance but little is known for the role of ABA catabolic genes during drought stress. In this study, we found that OsABA8ox3 was the most highly expressed gene of the OsABA8ox family in rice leaves. Expression of OsABA8ox3 was promptly induced by rehydration after PEG-mimic dehydration, a tendency opposite to the changes of ABA level. We therefore constructed rice OsABA8ox3 silencing (RNA interference, RNAi and overexpression plants. There were no obvious phenotype differences between the transgenic seedlings and wild type under normal condition. However, OsABA8ox3 RNAi lines showed significant improvement in drought stress tolerance while the overexpression seedlings were hypersensitive to drought stress when compared with wild type in terms of plant survival rates after 10 days of unwatering. Enzyme activity analysis indicated that OsABA8ox3 RNAi plants had higher superoxide dismutase (SOD and catalase (CAT activities and less malondialdehyde (MDA content than those of wild type when the plants were exposed to dehydration treatment, indicating a better anti-oxidative stress capability and less membrane damage. DNA microarray and real-time PCR analysis under dehydration treatment revealed that expressions of a group of stress/drought-related genes, i.e. LEA genes, were enhanced with higher transcript levels in OsABA8ox3 RNAi transgenic seedlings. We therefore conclude that that OsABA8ox3 gene plays an important role in controlling ABA level and drought stress resistance in rice.

  20. A key ABA catabolic gene, OsABA8ox3, is involved in drought stress resistance in rice.

    Science.gov (United States)

    Cai, Shanlan; Jiang, Guobin; Ye, Nenghui; Chu, Zhizhan; Xu, Xuezhong; Zhang, Jianhua; Zhu, Guohui

    2015-01-01

    Expressions of ABA biosynthesis genes and catabolism genes are generally co-regulated in plant development and responses to environmental stress. Up-regulation of OsNCED3 gene, a key gene in ABA biosynthesis, has been suggested as a way to enhance plant drought resistance but little is known for the role of ABA catabolic genes during drought stress. In this study, we found that OsABA8ox3 was the most highly expressed gene of the OsABA8ox family in rice leaves. Expression of OsABA8ox3 was promptly induced by rehydration after PEG-mimic dehydration, a tendency opposite to the changes of ABA level. We therefore constructed rice OsABA8ox3 silencing (RNA interference, RNAi) and overexpression plants. There were no obvious phenotype differences between the transgenic seedlings and wild type under normal condition. However, OsABA8ox3 RNAi lines showed significant improvement in drought stress tolerance while the overexpression seedlings were hypersensitive to drought stress when compared with wild type in terms of plant survival rates after 10 days of unwatering. Enzyme activity analysis indicated that OsABA8ox3 RNAi plants had higher superoxide dismutase (SOD) and catalase (CAT) activities and less malondialdehyde (MDA) content than those of wild type when the plants were exposed to dehydration treatment, indicating a better anti-oxidative stress capability and less membrane damage. DNA microarray and real-time PCR analysis under dehydration treatment revealed that expressions of a group of stress/drought-related genes, i.e. LEA genes, were enhanced with higher transcript levels in OsABA8ox3 RNAi transgenic seedlings. We therefore conclude that that OsABA8ox3 gene plays an important role in controlling ABA level and drought stress resistance in rice. PMID:25647508

  1. Identification and mechanism of ABA receptor antagonism

    KAUST Repository

    Melcher, Karsten

    2010-08-22

    The phytohormone abscisic acid (ABA) functions through a family of fourteen PYR/PYL receptors, which were identified by resistance to pyrabactin, a synthetic inhibitor of seed germination. ABA activates these receptors to inhibit type 2C protein phosphatases, such as ABI1, yet it remains unclear whether these receptors can be antagonized. Here we demonstrate that pyrabactin is an agonist of PYR1 and PYL1 but is unexpectedly an antagonist of PYL2. Crystal structures of the PYL2-pyrabactin and PYL1-pyrabactin-ABI1 complexes reveal the mechanism responsible for receptor-selective activation and inhibition, which enables us to design mutations that convert PYL1 to a pyrabactin-inhibited receptor and PYL2 to a pyrabactin-activated receptor and to identify new pyrabactin-based ABA receptor agonists. Together, our results establish a new concept of ABA receptor antagonism, illustrate its underlying mechanisms and provide a rational framework for discovering novel ABA receptor ligands. © 2010 Nature America, Inc. All rights reserved.

  2. Thermosensitive aqueous gels with tunable sol-gel transition temperatures from thermo- and pH-responsive hydrophilic ABA triblock copolymer.

    Science.gov (United States)

    O'Lenick, Thomas G; Jiang, Xueguang; Zhao, Bin

    2010-06-01

    This article reports on the synthesis of a well-defined hydrophilic ABA triblock copolymer composed of a poly(ethylene oxide) (PEO) middle block and thermo- and pH-sensitive outer blocks and the study of sol-gel transitions of its aqueous solutions at various pH values. The doubly responsive linear triblock copolymer, poly(methoxydi(ethylene glycol) methacrylate-co-methacrylic acid)-b-PEO-b-poly(methoxydi(ethylene glycol) methacrylate-co-methacrylic acid) (P(DEGMMA-co-MAA)-b-PEO-b-P(DEGMMA-co-MAA)), was prepared by atom transfer radical polymerization of a mixture of DEGMMA and tert-butyl methacrylate with a molar ratio of 100: 5 from a difunctional PEO macroinitiator and subsequent removal of tert-butyl groups using trifluoroacetic acid. Dynamic light scattering studies showed that the critical micellization temperature (CMT) of this ABA triblock copolymer in a 0.2 wt % aqueous solution was dependent on the solution pH and can be varied in a large temperature range (>20 degrees C). To study the sol-gel transitions, a 12.0 wt % aqueous solution of the triblock copolymer with a pH of 4.89 was made; its pH value can be readily changed and well controlled by the injection of either a 1.0 M HCl or a 1.0 M KOH solution. From rheological measurements, the sol-gel transition temperature (T(sol-gel)) versus pH curve was found to closely trace the CMT versus pH curve, though there was a shift. By cycling the solution pH between 3.2 and 5.4, we showed that the T(sol-gel) at a specific pH was reproducible. Moreover, multiple sol-gel-sol transitions were realized by judiciously controlling the temperature and pH simultaneously, demonstrating the possibility of achieving on-demand sol-gel transitions by using two external stimuli. In addition, the effect of polymer concentration on T(sol-gel) at pH = 4.0 was investigated. The sol-gel transition temperature increased with the decrease of polymer concentration and the critical gelation concentration was found to be between 4 and

  3. Thermosensitive aqueous gels with tunable sol-gel transition temperatures from thermo- and pH-responsive hydrophilic ABA triblock copolymer.

    Science.gov (United States)

    O'Lenick, Thomas G; Jiang, Xueguang; Zhao, Bin

    2010-06-01

    This article reports on the synthesis of a well-defined hydrophilic ABA triblock copolymer composed of a poly(ethylene oxide) (PEO) middle block and thermo- and pH-sensitive outer blocks and the study of sol-gel transitions of its aqueous solutions at various pH values. The doubly responsive linear triblock copolymer, poly(methoxydi(ethylene glycol) methacrylate-co-methacrylic acid)-b-PEO-b-poly(methoxydi(ethylene glycol) methacrylate-co-methacrylic acid) (P(DEGMMA-co-MAA)-b-PEO-b-P(DEGMMA-co-MAA)), was prepared by atom transfer radical polymerization of a mixture of DEGMMA and tert-butyl methacrylate with a molar ratio of 100: 5 from a difunctional PEO macroinitiator and subsequent removal of tert-butyl groups using trifluoroacetic acid. Dynamic light scattering studies showed that the critical micellization temperature (CMT) of this ABA triblock copolymer in a 0.2 wt % aqueous solution was dependent on the solution pH and can be varied in a large temperature range (>20 degrees C). To study the sol-gel transitions, a 12.0 wt % aqueous solution of the triblock copolymer with a pH of 4.89 was made; its pH value can be readily changed and well controlled by the injection of either a 1.0 M HCl or a 1.0 M KOH solution. From rheological measurements, the sol-gel transition temperature (T(sol-gel)) versus pH curve was found to closely trace the CMT versus pH curve, though there was a shift. By cycling the solution pH between 3.2 and 5.4, we showed that the T(sol-gel) at a specific pH was reproducible. Moreover, multiple sol-gel-sol transitions were realized by judiciously controlling the temperature and pH simultaneously, demonstrating the possibility of achieving on-demand sol-gel transitions by using two external stimuli. In addition, the effect of polymer concentration on T(sol-gel) at pH = 4.0 was investigated. The sol-gel transition temperature increased with the decrease of polymer concentration and the critical gelation concentration was found to be between 4 and

  4. ABA, ROS and NO are Key Players During Switchgrass Seed Germination

    OpenAIRE

    Sarath, Gautam; Hou, Guichuan; Baird, Lisa M.; Robert B Mitchell

    2007-01-01

    Seed dormancy and germination are complex physiological processes usually under hormonal control. Germination of seeds from many plants including switchgrass, are inhibited by ABA and promoted by NO or ROS. However, ABA apparently requires both ROS and NO as intermediates in its action, with ROS produced by membrane-bound NADPH-oxidases responsive to ABA. In switchgrass seeds, externally supplied hydrogen peroxide (ROS), but not NO will overcome ABA-imposed inhibition of germination. Stimulat...

  5. Molecular Cloning of a Glycyrrhiza uralensis F. Aquaporin GuPIP1 Up-regulated in Response to Drought, Salt and ABA Stress

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A PCR-based homologous cloning strategy was used to identify aquaporin genes from the roots of Chinese licorice ( Glycyrrhiza uralensis F. ). A 1236 bp cDNA with 870 bp open reading frame encoding a 290 amino acids aquaporin ortholog, GuPIP1, was successfully cloned and characterized. The deduced GuPIP1 protein contains six putative transmembrane domains; two conserved NPA motifs as well as the MIP and PIP family signature sequences. A rabbit polyclonal antibody against N-terminal peptide of GuPIP1 corresponded to a 31 kDa GuPIP1 protein on Western blot of plasma membrane preparation of root tissue. RT-PCR and Western blot analysis indicated the expression of GuPIP1 in the root, leaf, and stem tissues. Thus far, GuPIP1 is the first Glycyrrhiza uralensis F. aquaporin that has been identified at a molecular level. Quantitative real-time PCR analysis showed that the expression of GuPIP1 was up-regulated in response to drought, ABA, and salt stress.

  6. The grapevine guard cell-related VvMYB60 transcription factor is involved in the regulation of stomatal activity and is differentially expressed in response to ABA and osmotic stress

    Directory of Open Access Journals (Sweden)

    Conti Lucio

    2011-10-01

    Full Text Available Abstract Background Under drought, plants accumulate the signaling hormone abscisic acid (ABA, which induces the rapid closure of stomatal pores to prevent water loss. This event is trigged by a series of signals produced inside guard cells which finally reduce their turgor. Many of these events are tightly regulated at the transcriptional level, including the control exerted by MYB proteins. In a previous study, while identifying the grapevine R2R3 MYB family, two closely related genes, VvMYB30 and VvMYB60 were found with high similarity to AtMYB60, an Arabidopsis guard cell-related drought responsive gene. Results Promoter-GUS transcriptional fusion assays showed that expression of VvMYB60 was restricted to stomatal guard cells and was attenuated in response to ABA. Unlike VvMYB30, VvMYB60 was able to complement the loss-of-function atmyb60-1 mutant, indicating that VvMYB60 is the only true ortholog of AtMYB60 in the grape genome. In addition, VvMYB60 was differentially regulated during development of grape organs and in response to ABA and drought-related stress conditions. Conclusions These results show that VvMYB60 modulates physiological responses in guard cells, leading to the possibility of engineering stomatal conductance in grapevine, reducing water loss and helping this species to tolerate drought under extreme climatic conditions.

  7. Genome Wide Transcriptome Analysis reveals ABA mediated response in Arabidopsis during Gold (AuCl4-) treatment

    OpenAIRE

    Devesh eShukla; Sneha eKrishnamurthy; Shivendra Vikram Sahi

    2014-01-01

    The unique physico-chemical properties of gold nanoparticles (AuNPs) find manifold applications in diagnostics, medicine and catalysis. Chemical synthesis produces reactive AuNPs and generates hazardous by-products. Alternatively, plants can be utilized to produce AuNPs in an eco-friendly manner. To better control the biosynthesis of AuNPs, we need to first understand the detailed molecular response induced by AuCl4- In this study, we carried out global transcriptome analysis in root tissue ...

  8. Genome wide transcriptome analysis reveals ABA mediated response in Arabidopsis during gold (AuCl− 4) treatment

    OpenAIRE

    Shukla, Devesh; Krishnamurthy, Sneha; Shivendra V. Sahi

    2014-01-01

    The unique physico-chemical properties of gold nanoparticles (AuNPs) find manifold applications in diagnostics, medicine and catalysis. Chemical synthesis produces reactive AuNPs and generates hazardous by-products. Alternatively, plants can be utilized to produce AuNPs in an eco-friendly manner. To better control the biosynthesis of AuNPs, we need to first understand the detailed molecular response induced by AuCl− 4 In this study, we carried out global transcriptome analysis in root tissue ...

  9. Genome wide transcriptome analysis reveals ABA mediated response in Arabidopsis during gold (AuCl−4) treatment

    OpenAIRE

    Shukla, Devesh; Krishnamurthy, Sneha; Shivendra V. Sahi

    2014-01-01

    The unique physico-chemical properties of gold nanoparticles (AuNPs) find manifold applications in diagnostics, medicine and catalysis. Chemical synthesis produces reactive AuNPs and generates hazardous by-products. Alternatively, plants can be utilized to produce AuNPs in an eco-friendly manner. To better control the biosynthesis of AuNPs, we need to first understand the detailed molecular response induced by AuCl−4 In this study, we carried out global transcriptome analysis in root tissue o...

  10. Local root abscisic acid (ABA) accumulation depends on the spatial distribution of soil moisture in potato: implications for ABA signalling under heterogeneous soil drying.

    Science.gov (United States)

    Puértolas, Jaime; Conesa, María R; Ballester, Carlos; Dodd, Ian C

    2015-04-01

    Patterns of root abscisic acid (ABA) accumulation ([ABA]root), root water potential (Ψroot), and root water uptake (RWU), and their impact on xylem sap ABA concentration ([X-ABA]) were measured under vertical partial root-zone drying (VPRD, upper compartment dry, lower compartment wet) and horizontal partial root-zone drying (HPRD, two lateral compartments: one dry, the other wet) of potato (Solanum tuberosum L.). When water was withheld from the dry compartment for 0-10 d, RWU and Ψroot were similarly lower in the dry compartment when soil volumetric water content dropped below 0.22cm(3) cm(-3) for both spatial distributions of soil moisture. However, [ABA]root increased in response to decreasing Ψroot in the dry compartment only for HPRD, resulting in much higher ABA accumulation than in VPRD. The position of the sampled roots (~4cm closer to the surface in the dry compartment of VPRD than in HPRD) might account for this difference, since older (upper) roots may accumulate less ABA in response to decreased Ψroot than younger (deeper) roots. This would explain differences in root ABA accumulation patterns under vertical and horizontal soil moisture gradients reported in the literature. In our experiment, these differences in root ABA accumulation did not influence [X-ABA], since the RWU fraction (and thus ABA export to shoots) from the dry compartment dramatically decreased simultaneously with any increase in [ABA]root. Thus, HPRD might better trigger a long-distance ABA signal than VPRD under conditions allowing simultaneous high [ABA]root and relatively high RWU fraction.

  11. Compound stress response in stomatal closure: a mathematical model of ABA and ethylene interaction in guard cells

    Directory of Open Access Journals (Sweden)

    Beguerisse-Dıaz Mariano

    2012-11-01

    Full Text Available Abstract Background Stomata are tiny pores in plant leaves that regulate gas and water exchange between the plant and its environment. Abscisic acid and ethylene are two well-known elicitors of stomatal closure when acting independently. However, when stomata are presented with a combination of both signals, they fail to close. Results Toshed light on this unexplained behaviour, we have collected time course measurements of stomatal aperture and hydrogen peroxide production in Arabidopsis thaliana guard cells treated with abscisic acid, ethylene, and a combination of both. Our experiments show that stomatal closure is linked to sustained high levels of hydrogen peroxide in guard cells. When treated with a combined dose of abscisic acid and ethylene, guard cells exhibit increased antioxidant activity that reduces hydrogen peroxide levels and precludes closure. We construct a simplified model of stomatal closure derived from known biochemical pathways that captures the experimentally observed behaviour. Conclusions Our experiments and modelling results suggest a distinct role for two antioxidant mechanisms during stomatal closure: a slower, delayed response activated by a single stimulus (abscisic acid ‘or’ ethylene and another more rapid ‘and’ mechanism that is only activated when both stimuli are present. Our model indicates that the presence of this rapid ‘and’ mechanism in the antioxidant response is key to explain the lack of closure under a combined stimulus.

  12. ABA receptor PYL9 promotes drought resistance and leaf senescence

    OpenAIRE

    Zhao, Yang; Chan, Zhulong; Gao, Jinghui; Xing, Lu; Cao, Minjie; Yu, Chunmei; Hu, Yuanlei; You, Jun; Shi, Haitao; Zhu, Yingfang; Gong, Yuehua; Mu, Zixin; Wang, Haiqing; Deng, Xin; Wang, Pengcheng

    2016-01-01

    We identified transgenic plants that are extremely resistant to drought from a large-scale screening of transgenic plants overexpressing the pyrabactin resistance 1-like (PYL) family of abscisic acid (ABA) receptors. We explored how these plants resist drought by examining both short-term responses, such as stomatal closure, and long-term responses, such as senescence. The physiological roles of ABA-induced senescence under stress conditions and the underlying molecular mechanism are unclear....

  13. A LEA 4 protein up-regulated by ABA is involved in drought response in maize roots.

    Science.gov (United States)

    Zamora-Briseño, Jesús Alejandro; de Jiménez, Estela Sánchez

    2016-04-01

    Late embryogenesis abundant (LEA) proteins are hydrophilic proteins that accumulate to high concentrations during the late stages of seeds development, which are integral to desiccation tolerance. LEA proteins also play a protective role under other abiotic stresses. We analyzed in silico a maize protein predicted to be highly hydrophilic and intrinsically disordered. This prediction was experimentally corroborated by solubility assays under denaturing conditions. Based on its amino acid sequence, we propose that this protein belongs to group four of the LEA proteins. The accumulation pattern of this protein was similar to that of dehydrins during the desiccation process that takes place during seed development. This protein was induced by exogenous abscisic acid in immature embryos, but during imbibition was down-regulated by gibberellins. It was also induced in maize roots under osmotic stress. So far, this is the first member of the LEA proteins belonging to group four to be characterized in maize, and it plays a role in the response to osmotic stress. PMID:26922182

  14. A Randomized Clinical Trial Comparison between Pivotal Response Treatment (PRT) and Structured Applied Behavior Analysis (ABA) Intervention for Children with Autism

    Science.gov (United States)

    Mohammadzaheri, Fereshteh; Koegel, Lynn Kern; Rezaee, Mohammad; Rafiee, Seyed Majid

    2014-01-01

    Accumulating studies are documenting specific motivational variables that, when combined into a naturalistic teaching paradigm, can positively influence the effectiveness of interventions for children with autism spectrum disorder (ASD). The purpose of this study was to compare two applied behavior analysis (ABA) intervention procedures, a…

  15. Function of ABA in Stomatal Defense against Biotic and Drought Stresses.

    Science.gov (United States)

    Lim, Chae Woo; Baek, Woonhee; Jung, Jangho; Kim, Jung-Hyun; Lee, Sung Chul

    2015-01-01

    The plant hormone abscisic acid (ABA) regulates many key processes involved in plant development and adaptation to biotic and abiotic stresses. Under stress conditions, plants synthesize ABA in various organs and initiate defense mechanisms, such as the regulation of stomatal aperture and expression of defense-related genes conferring resistance to environmental stresses. The regulation of stomatal opening and closure is important to pathogen defense and control of transpirational water loss. Recent studies using a combination of approaches, including genetics, physiology, and molecular biology, have contributed considerably to our understanding of ABA signal transduction. A number of proteins associated with ABA signaling and responses--especially ABA receptors--have been identified. ABA signal transduction initiates signal perception by ABA receptors and transfer via downstream proteins, including protein kinases and phosphatases. In the present review, we focus on the function of ABA in stomatal defense against biotic and abiotic stresses, through analysis of each ABA signal component and the relationships of these components in the complex network of interactions. In particular, two ABA signal pathway models in response to biotic and abiotic stress were proposed, from stress signaling to stomatal closure, involving the pyrabactin resistance (PYR)/PYR-like (PYL) or regulatory component of ABA receptor (RCAR) family proteins, 2C-type protein phosphatases, and SnRK2-type protein kinases. PMID:26154766

  16. ABA receptor PYL9 promotes drought resistance and leaf senescence.

    Science.gov (United States)

    Zhao, Yang; Chan, Zhulong; Gao, Jinghui; Xing, Lu; Cao, Minjie; Yu, Chunmei; Hu, Yuanlei; You, Jun; Shi, Haitao; Zhu, Yingfang; Gong, Yuehua; Mu, Zixin; Wang, Haiqing; Deng, Xin; Wang, Pengcheng; Bressan, Ray A; Zhu, Jian-Kang

    2016-02-16

    Drought stress is an important environmental factor limiting plant productivity. In this study, we screened drought-resistant transgenic plants from 65 promoter-pyrabactin resistance 1-like (PYL) abscisic acid (ABA) receptor gene combinations and discovered that pRD29A::PYL9 transgenic lines showed dramatically increased drought resistance and drought-induced leaf senescence in both Arabidopsis and rice. Previous studies suggested that ABA promotes senescence by causing ethylene production. However, we found that ABA promotes leaf senescence in an ethylene-independent manner by activating sucrose nonfermenting 1-related protein kinase 2s (SnRK2s), which subsequently phosphorylate ABA-responsive element-binding factors (ABFs) and Related to ABA-Insensitive 3/VP1 (RAV1) transcription factors. The phosphorylated ABFs and RAV1 up-regulate the expression of senescence-associated genes, partly by up-regulating the expression of Oresara 1. The pyl9 and ABA-insensitive 1-1 single mutants, pyl8-1pyl9 double mutant, and snrk2.2/3/6 triple mutant showed reduced ABA-induced leaf senescence relative to the WT, whereas pRD29A::PYL9 transgenic plants showed enhanced ABA-induced leaf senescence. We found that leaf senescence may benefit drought resistance by helping to generate an osmotic potential gradient, which is increased in pRD29A::PYL9 transgenic plants and causes water to preferentially flow to developing tissues. Our results uncover the molecular mechanism of ABA-induced leaf senescence and suggest an important role of PYL9 and leaf senescence in promoting resistance to extreme drought stress.

  17. ABA receptor PYL9 promotes drought resistance and leaf senescence.

    Science.gov (United States)

    Zhao, Yang; Chan, Zhulong; Gao, Jinghui; Xing, Lu; Cao, Minjie; Yu, Chunmei; Hu, Yuanlei; You, Jun; Shi, Haitao; Zhu, Yingfang; Gong, Yuehua; Mu, Zixin; Wang, Haiqing; Deng, Xin; Wang, Pengcheng; Bressan, Ray A; Zhu, Jian-Kang

    2016-02-16

    Drought stress is an important environmental factor limiting plant productivity. In this study, we screened drought-resistant transgenic plants from 65 promoter-pyrabactin resistance 1-like (PYL) abscisic acid (ABA) receptor gene combinations and discovered that pRD29A::PYL9 transgenic lines showed dramatically increased drought resistance and drought-induced leaf senescence in both Arabidopsis and rice. Previous studies suggested that ABA promotes senescence by causing ethylene production. However, we found that ABA promotes leaf senescence in an ethylene-independent manner by activating sucrose nonfermenting 1-related protein kinase 2s (SnRK2s), which subsequently phosphorylate ABA-responsive element-binding factors (ABFs) and Related to ABA-Insensitive 3/VP1 (RAV1) transcription factors. The phosphorylated ABFs and RAV1 up-regulate the expression of senescence-associated genes, partly by up-regulating the expression of Oresara 1. The pyl9 and ABA-insensitive 1-1 single mutants, pyl8-1pyl9 double mutant, and snrk2.2/3/6 triple mutant showed reduced ABA-induced leaf senescence relative to the WT, whereas pRD29A::PYL9 transgenic plants showed enhanced ABA-induced leaf senescence. We found that leaf senescence may benefit drought resistance by helping to generate an osmotic potential gradient, which is increased in pRD29A::PYL9 transgenic plants and causes water to preferentially flow to developing tissues. Our results uncover the molecular mechanism of ABA-induced leaf senescence and suggest an important role of PYL9 and leaf senescence in promoting resistance to extreme drought stress. PMID:26831097

  18. Function of ABA in Stomatal Defense against Biotic and Drought Stresses

    Directory of Open Access Journals (Sweden)

    Chae Woo Lim

    2015-07-01

    Full Text Available The plant hormone abscisic acid (ABA regulates many key processes involved in plant development and adaptation to biotic and abiotic stresses. Under stress conditions, plants synthesize ABA in various organs and initiate defense mechanisms, such as the regulation of stomatal aperture and expression of defense-related genes conferring resistance to environmental stresses. The regulation of stomatal opening and closure is important to pathogen defense and control of transpirational water loss. Recent studies using a combination of approaches, including genetics, physiology, and molecular biology, have contributed considerably to our understanding of ABA signal transduction. A number of proteins associated with ABA signaling and responses—especially ABA receptors—have been identified. ABA signal transduction initiates signal perception by ABA receptors and transfer via downstream proteins, including protein kinases and phosphatases. In the present review, we focus on the function of ABA in stomatal defense against biotic and abiotic stresses, through analysis of each ABA signal component and the relationships of these components in the complex network of interactions. In particular, two ABA signal pathway models in response to biotic and abiotic stress were proposed, from stress signaling to stomatal closure, involving the pyrabactin resistance (PYR/PYR-like (PYL or regulatory component of ABA receptor (RCAR family proteins, 2C-type protein phosphatases, and SnRK2-type protein kinases.

  19. Type One Protein Phosphatase 1 and Its Regulatory Protein Inhibitor 2 Negatively Regulate ABA Signaling

    Science.gov (United States)

    Zhao, Yang; Xie, Shaojun; Batelli, Giorgia; Wang, Bangshing; Duan, Cheng-Guo; Wang, Xingang; Xing, Lu; Lei, Mingguang; Yan, Jun; Zhu, Xiaohong; Zhu, Jian-Kang

    2016-01-01

    The phytohormone abscisic acid (ABA) regulates plant growth, development and responses to biotic and abiotic stresses. The core ABA signaling pathway consists of three major components: ABA receptor (PYR1/PYLs), type 2C Protein Phosphatase (PP2C) and SNF1-related protein kinase 2 (SnRK2). Nevertheless, the complexity of ABA signaling remains to be explored. To uncover new components of ABA signal transduction pathways, we performed a yeast two-hybrid screen for SnRK2-interacting proteins. We found that Type One Protein Phosphatase 1 (TOPP1) and its regulatory protein, At Inhibitor-2 (AtI-2), physically interact with SnRK2s and also with PYLs. TOPP1 inhibited the kinase activity of SnRK2.6, and this inhibition could be enhanced by AtI-2. Transactivation assays showed that TOPP1 and AtI-2 negatively regulated the SnRK2.2/3/6-mediated activation of the ABA responsive reporter gene RD29B, supporting a negative role of TOPP1 and AtI-2 in ABA signaling. Consistent with these findings, topp1 and ati-2 mutant plants displayed hypersensitivities to ABA and salt treatments, and transcriptome analysis of TOPP1 and AtI-2 knockout plants revealed an increased expression of multiple ABA-responsive genes in the mutants. Taken together, our results uncover TOPP1 and AtI-2 as negative regulators of ABA signaling. PMID:26943172

  20. Comprehensive Analysis of ABA Effects on Ethylene Biosynthesis and Signaling during Tomato Fruit Ripening.

    Science.gov (United States)

    Mou, Wangshu; Li, Dongdong; Bu, Jianwen; Jiang, Yuanyuan; Khan, Zia Ullah; Luo, Zisheng; Mao, Linchun; Ying, Tiejin

    2016-01-01

    ABA has been widely acknowledged to regulate ethylene biosynthesis and signaling during fruit ripening, but the molecular mechanism underlying the interaction between these two hormones are largely unexplored. In the present study, exogenous ABA treatment obviously promoted fruit ripening as well as ethylene emission, whereas NDGA (Nordihydroguaiaretic acid, an inhibitor of ABA biosynthesis) application showed the opposite biological effects. Combined RNA-seq with time-course RT-PCR analysis, our study not only helped to illustrate how ABA regulated itself at the transcription level, but also revealed that ABA can facilitate ethylene production and response probably by regulating some crucial genes such as LeACS4, LeACO1, GR and LeETR6. In addition, investigation on the fruits treated with 1-MCP immediately after ABA exposure revealed that ethylene might be essential for the induction of ABA biosynthesis and signaling at the onset of fruit ripening. Furthermore, some specific transcription factors (TFs) known as regulators of ethylene synthesis and sensibility (e.g. MADS-RIN, TAGL1, CNR and NOR) were also observed to be ABA responsive, which implied that ABA influenced ethylene action possibly through the regulation of these TFs expression. Our comprehensive physiological and molecular-level analysis shed light on the mechanism of cross-talk between ABA and ethylene during the process of tomato fruit ripening. PMID:27100326

  1. Common and unique elements of the ABA-regulated transcriptome of Arabidopsis guard cells

    Directory of Open Access Journals (Sweden)

    Zhao Zhixin

    2011-05-01

    Full Text Available Abstract Background In the presence of drought and other desiccating stresses, plants synthesize and redistribute the phytohormone abscisic acid (ABA. ABA promotes plant water conservation by acting on specialized cells in the leaf epidermis, guard cells, which border and regulate the apertures of stomatal pores through which transpirational water loss occurs. Following ABA exposure, solute uptake into guard cells is rapidly inhibited and solute loss is promoted, resulting in inhibition of stomatal opening and promotion of stomatal closure, with consequent plant water conservation. There is a wealth of information on the guard cell signaling mechanisms underlying these rapid ABA responses. To investigate ABA regulation of gene expression in guard cells in a systematic genome-wide manner, we analyzed data from global transcriptomes of guard cells generated with Affymetrix ATH1 microarrays, and compared these results to ABA regulation of gene expression in leaves and other tissues. Results The 1173 ABA-regulated genes of guard cells identified by our study share significant overlap with ABA-regulated genes of other tissues, and are associated with well-defined ABA-related promoter motifs such as ABREs and DREs. However, we also computationally identified a unique cis-acting motif, GTCGG, associated with ABA-induction of gene expression specifically in guard cells. In addition, approximately 300 genes showing ABA-regulation unique to this cell type were newly uncovered by our study. Within the ABA-regulated gene set of guard cells, we found that many of the genes known to encode ion transporters associated with stomatal opening are down-regulated by ABA, providing one mechanism for long-term maintenance of stomatal closure during drought. We also found examples of both negative and positive feedback in the transcriptional regulation by ABA of known ABA-signaling genes, particularly with regard to the PYR/PYL/RCAR class of soluble ABA receptors and

  2. Physiological impacts of ABA-JA interactions under water-limitation.

    Science.gov (United States)

    de Ollas, Carlos; Dodd, Ian C

    2016-08-01

    Plant responses to drought stress depend on highly regulated signal transduction pathways with multiple interactions. This complex crosstalk can lead to a physiological outcome of drought avoidance or tolerance/resistance. ABA is the principal mediator of these responses due to the regulation of stomatal closure that determines plant growth and survival, but also other strategies of drought resistance such as osmotic adjustment. However, other hormones such as JA seem responsible for regulating a subset of plant responses to drought by regulating ABA biosynthesis and accumulation and ABA-dependent signalling, but also by ABA independent pathways. Here, we review recent reports of ABA-JA hormonal and molecular interactions within a physiological framework of drought tolerance. Understanding the physiological significance of this complex regulation offers opportunities to find strategies of drought tolerance that avoid unwanted side effects that limit growth and yield, and may allow biotechnological crop improvement.

  3. Physiological impacts of ABA-JA interactions under water-limitation.

    Science.gov (United States)

    de Ollas, Carlos; Dodd, Ian C

    2016-08-01

    Plant responses to drought stress depend on highly regulated signal transduction pathways with multiple interactions. This complex crosstalk can lead to a physiological outcome of drought avoidance or tolerance/resistance. ABA is the principal mediator of these responses due to the regulation of stomatal closure that determines plant growth and survival, but also other strategies of drought resistance such as osmotic adjustment. However, other hormones such as JA seem responsible for regulating a subset of plant responses to drought by regulating ABA biosynthesis and accumulation and ABA-dependent signalling, but also by ABA independent pathways. Here, we review recent reports of ABA-JA hormonal and molecular interactions within a physiological framework of drought tolerance. Understanding the physiological significance of this complex regulation offers opportunities to find strategies of drought tolerance that avoid unwanted side effects that limit growth and yield, and may allow biotechnological crop improvement. PMID:27299601

  4. Identification and characterization of an ABA-activated MAP kinase cascade in Arabidopsis thaliana

    KAUST Repository

    Danquah, Agyemang

    2015-04-01

    Summary Abscisic acid (ABA) is a major phytohormone involved in important stress-related and developmental plant processes. Recent phosphoproteomic analyses revealed a large set of ABA-triggered phosphoproteins as putative mitogen-activated protein kinase (MAPK) targets, although the evidence for MAPKs involved in ABA signalling is still scarce. Here, we identified and reconstituted in vivo a complete ABA-activated MAPK cascade, composed of the MAP3Ks MAP3K17/18, the MAP2K MKK3 and the four C group MAPKs MPK1/2/7/14. In planta, we show that ABA activation of MPK7 is blocked in mkk3-1 and map3k17mapk3k18 plants. Coherently, both mutants exhibit hypersensitivity to ABA and altered expression of a set of ABA-dependent genes. A genetic analysis further reveals that this MAPK cascade is activated by the PYR/PYL/RCAR-SnRK2-PP2C ABA core signalling module through protein synthesis of the MAP3Ks, unveiling an atypical mechanism for MAPK activation in eukaryotes. Our work provides evidence for a role of an ABA-induced MAPK pathway in plant stress signalling. Significance Statement We report in this article the identification of a complete MAPK module, composed of MAP3K17/18, MKK3 and MPK1/2/7/14, which is activated by ABA through the ABA core signalling complex. We showed that the activation of this module requires the MAP3K protein synthesis which occurs after hours of stress treatment, suggesting that the pathway is involved in a delayed wave of cellular responses to ABA and drought. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  5. The site of water stress governs the pattern of ABA synthesis and transport in peanut

    Science.gov (United States)

    Hu, Bo; Cao, Jiajia; Ge, Kui; Li, Ling

    2016-01-01

    Abscisic acid (ABA) is one of the most important phytohormones involved in stress responses in plants. However, knowledge of the effect on ABA distribution and transport of water stress at different sites on the plant is limited. In this study, water stress imposed on peanut leaves or roots by treatment with PEG 6000 is termed “leaf stress” or “root stress”, respectively. Immunoenzyme localization technolony was first used to detect ABA distribution in peanut. Under root stress, ABA biosynthesis and distribution level were all more pronounced in root than in leaf. However, ABA transport and the ability to induce stomatal closure were still better in leaf than in root during root stress; However, ABA biosynthesis initially increased in leaf, then rapidly accumulated in the vascular cambium of leaves and induced stomatal closure under leaf stress; ABA produced in root tissues was also transported to leaf tissues to maintain stomatal closure. The vascular system was involved in the coordination and integration of this complex regulatory mechanism for ABA signal accumulation. Water stress subject to root or leaf results in different of ABA biosynthesis and transport ability that trigger stoma close in peanut. PMID:27694957

  6. ABA receptors: The START of a new paradigm in phytohormone signalling

    KAUST Repository

    Klingler, John

    2010-06-03

    The phytohormone abscisic acid (ABA) plays a central role in plant development and in plant adaptation to both biotic and abiotic stressors. In recent years, knowledge of ABA metabolism and signal transduction has advanced rapidly to provide detailed glimpses of the hormone\\'s activities at the molecular level. Despite this progress, many gaps in understanding have remained, particularly at the early stages of ABA perception by the plant cell. The search for an ABA receptor protein has produced multiple candidates, including GCR2, GTG1, and GTG2, and CHLH. In addition to these candidates, in 2009 several research groups converged on a novel family of Arabidopsis proteins that bind ABA, and thereby interact directly with a class of protein phosphatases that are well known as critical players in ABA signal transduction. The PYR/PYL/RCAR receptor family is homologous to the Bet v 1-fold and START domain proteins. It consists of 14 members, nearly all of which appear capable of participating in an ABA receptor-signal complex that responds to the hormone by activating the transcription of ABA-responsive genes. Evidence is provided here that PYR/PYL/RCAR receptors can also drive the phosphorylation of the slow anion channel SLAC1 to provide a fast and timely response to the ABA signal. Crystallographic studies have vividly shown the mechanics of ABA binding to PYR/PYL/RCAR receptors, presenting a model that bears some resemblance to the binding of gibberellins to GID1 receptors. Since this ABA receptor family is highly conserved in crop species, its discovery is likely to usher a new wave of progress in the elucidation and manipulation of plant stress responses in agricultural settings. © 2010 The Author(s).

  7. Towards the Identification of New Genes Involved in ABA-Dependent Abiotic Stresses Using Arabidopsis Suppressor Mutants of abh1 Hypersensitivity to ABA during Seed Germination

    Directory of Open Access Journals (Sweden)

    Iwona Szarejko

    2013-06-01

    Full Text Available Abscisic acid plays a pivotal role in the abiotic stress response in plants. Although great progress has been achieved explaining the complexity of the stress and ABA signaling cascade, there are still many questions to answer. Mutants are a valuable tool in the identification of new genes or new alleles of already known genes and in elucidating their role in signaling pathways. We applied a suppressor mutation approach in order to find new components of ABA and abiotic stress signaling in Arabidopsis. Using the abh1 (ABA hypersensitive 1 insertional mutant as a parental line for EMS mutagenesis, we selected several mutants with suppressed hypersensitivity to ABA during seed germination. Here, we present the response to ABA and a wide range of abiotic stresses during the seed germination and young seedling development of two suppressor mutants—soa2 (suppressor of abh1 hypersensitivity to ABA 2 and soa3 (suppressor of abh1 hypersensitivity to ABA 3. Generally, both mutants displayed a suppression of the hypersensitivity of abh1 to ABA, NaCl and mannitol during germination. Both mutants showed a higher level of tolerance than Columbia-0 (Col-0—the parental line of abh1 in high concentrations of glucose. Additionally, soa2 exhibited better root growth than Col-0 in the presence of high ABA concentrations. soa2 and soa3 were drought tolerant and both had about 50% fewer stomata per mm2 than the wild-type but the same number as their parental line—abh1. Taking into account that suppressor mutants had the same genetic background as their parental line—abh1, it was necessary to backcross abh1 with Landsberg erecta four times for the map-based cloning approach. Mapping populations, derived from the cross of abh1 in the Landsberg erecta background with each suppressor mutant, were created. Map based cloning in order to identify the suppressor genes is in progress.

  8. RAS1, a quantitative trait locus for salt tolerance and ABA sensitivity in Arabidopsis

    KAUST Repository

    Ren, Zhonghai

    2010-03-08

    Soil salinity limits agricultural production and is a major obstacle for feeding the growing world population. We used natural genetic variation in salt tolerance among different Arabidopsis accessions to map a major quantitative trait locus (QTL) for salt tolerance and abscisic acid (ABA) sensitivity during seed germination and early seedling growth. A recombinant inbred population derived from Landsberg erecta (Ler; salt and ABA sensitive) x Shakdara (Sha; salt and ABA resistant) was used for QTL mapping. High-resolution mapping and cloning of this QTL, Response to ABA and Salt 1 (RAS1), revealed that it is an ABA- and salt stress-inducible gene and encodes a previously undescribed plant-specific protein. A premature stop codon results in a truncated RAS1 protein in Sha. Reducing the expression of RAS1 by transfer-DNA insertion in Col or RNA interference in Ler leads to decreased salt and ABA sensitivity, whereas overexpression of the Ler allele but not the Sha allele causes increased salt and ABA sensitivity. Our results suggest that RAS1 functions as a negative regulator of salt tolerance during seed germination and early seedling growth by enhancing ABA sensitivity and that its loss of function contributes to the increased salt tolerance of Sha.

  9. Overexpression of the Artemisia orthologue of ABA receptor, AaPYL9, enhances ABA sensitivity and improves artemisinin content in Artemisia annua L.

    Directory of Open Access Journals (Sweden)

    Fangyuan Zhang

    Full Text Available The phytohormone abscisic acid (ABA plays an important role in plant development and environmental stress response. In this study, we cloned an ABA receptor orthologue, AaPYL9, from Artemisia annua L. AaPYL9 is expressed highly in leaf and flower. AaPYL9 protein can be localized in both nucleus and cytoplasm. Yeast two-hybrid assay shows AaPYL9 can specifically interact with AtABI1 but not with AtABI2, AtHAB1 or AtHAB2. ABA can enhance the interaction between AaPYL9 and AtABI1 while AaPYL9-89 Pro→Ser and AaPYL9-116 His→Ala point mutations abolishes the interaction. BiFC assay shows that AaPYL9 interacts with AtABI1 in nucleus in planta. Transgenic Arabidopsis plants over-expressing AaPYL9 are more sensitive to ABA in the seed germination and primary root growth than wild type. Consistent with this, ABA report genes have higher expression in AaPYL9 overexpressing plants compared to wild type after ABA treatment. Moreover, overexpression of AaPYL9 in A. annua increases not only drought tolerance, but also artemisinin content after ABA treatment, with significant enhancement of the expression of key genes in artemisinin biosynthesis. This study provides a way to develop A. annua with high-yielding artemisinin and high drought resistance.

  10. Science for sale in a free market economy: But at what price? ABA and the treatment of autism in Europe.

    OpenAIRE

    Mickey Keenan, U.U.; Dillenburger, Karola; Röttgers, Hanns-Rüdiger; Moderato, Paolo

    2010-01-01

    Educating the public accurately about Applied Behavior Analysis (ABA) is an important undertaking, not least because misconceptions and myths about ABA abound. In this paper we argue that, unfortunately, the efforts of many dedicated professionals and parents to disseminate accurate information about the benefits of ABA for children diagnosed with autism spectrum disorder (ASD) are damaged by a few behavior analysts whose focus seems to be more on monetary gains than social responsibility. We...

  11. The Arabidopsis transcription factor ABIG1 relays ABA signaled growth inhibition and drought induced senescence

    Science.gov (United States)

    Liu, Tie; Longhurst, Adam D; Talavera-Rauh, Franklin; Hokin, Samuel A; Barton, M Kathryn

    2016-01-01

    Drought inhibits plant growth and can also induce premature senescence. Here we identify a transcription factor, ABA INSENSITIVE GROWTH 1 (ABIG1) required for abscisic acid (ABA) mediated growth inhibition, but not for stomatal closure. ABIG1 mRNA levels are increased both in response to drought and in response to ABA treatment. When treated with ABA, abig1 mutants remain greener and produce more leaves than comparable wild-type plants. When challenged with drought, abig1 mutants have fewer yellow, senesced leaves than wild-type. Induction of ABIG1 transcription mimics ABA treatment and regulates a set of genes implicated in stress responses. We propose a model in which drought acts through ABA to increase ABIG1 transcription which in turn restricts new shoot growth and promotes leaf senescence. The results have implications for plant breeding: the existence of a mutant that is both ABA resistant and drought resistant points to new strategies for isolating drought resistant genetic varieties. DOI: http://dx.doi.org/10.7554/eLife.13768.001 PMID:27697148

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

    Directory of Open Access Journals (Sweden)

    Francesca Secchi

    2012-12-01

    Full Text Available 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.

  13. Transcriptomic network analyses of leaf dehydration responses identify highly connected ABA and ethylene signaling hubs in three grapevine species differing in drought tolerance

    OpenAIRE

    Hopper, Daniel W.; Ghan, Ryan; Schlauch, Karen A; Grant R Cramer

    2016-01-01

    Background Grapevine is a major food crop that is affected by global climate change. Consistent with field studies, dehydration assays of grapevine leaves can reveal valuable information of the plant’s response at physiological, transcript, and protein levels. There are well-known differences in grapevine rootstocks responses to dehydration. We used time-series transcriptomic approaches combined with network analyses to elucidate and identify important physiological processes and network hubs...

  14. Roles of ABA Signal Transduction during Higher Plant Seed Development and Germination

    Institute of Scientific and Technical Information of China (English)

    Shao Hongbo; Liang Zongsuo; Shao Mingan

    2003-01-01

    ABA is one of the 5 phytohormones in higher plants, which is also the most important hormone that regulates higher plants in response to environmental stress, by ABA signal transduction. Understanding ABA signal transduction at the molecular level is crucial to biology and ecology, and rational breeding complied with corresponding eco-environmental changes.Great advancements have taken place over the past 10 years by application of the 4rabidopsis experimental system. Many components involved in ABA signal transduction have been isolated and identified and a clear overall picture of gene expression and control for this transduction has become an Accepted fact. On the basis of the work in our laboratory, in conjunction with the data available at the moment, the authors have attempted to integrate ABA signal transduction pathways into a common one and give some insights into the relationship between ABA signal transduction and other hormone signal transduction pathways, with an emphasis upon the ABA signal transduction during higher plant seed development. A future challenge in this field is that different experimental systems are applied and various receptors and genes need to be characterized through the utilization of microarray chips.

  15. Application of ABA Principles to General Communication Instruction.

    Science.gov (United States)

    Ogletree, Billy T.; Oren, Thomas

    2001-01-01

    This article examines applied behavior analysis (ABA) based communication instruction for students with autism. It offers an historical context for ABA in speech-language pathology and reviews the literature on the use of ABA as a treatment method for communication impairment in autism, comparing contemporary ABA with the developmental…

  16. Functional characterization and reconstitution of ABA signaling components using transient gene expression in rice protoplasts

    Directory of Open Access Journals (Sweden)

    Namhyo eKim

    2015-08-01

    Full Text Available The core component of ABA-dependent gene expression signaling have been identified in Arabidopsis and rice. This signaling pathway consists of four major components; group A OsbZIPs, SAPKs, subclass A OsPP2Cs and OsPYL/RCARs in rice. These might be able to make thousands of combinations through interaction networks resulting in diverse signaling responses. We tried to characterize those gene functions using transient gene expression for rice protoplasts (TGERP because it is instantaneous and convenient system. Firstly, in order to monitor the ABA signaling output, we developed reporter system named pRab16A-fLUC which consists of Rab16A promoter of rice and luciferase gene. It responses more rapidly and sensitively to ABA than pABRC3-fLUC that consists of ABRC3 of HVA1 promoter in TGERP. We screened the reporter responses for over-expression of each signaling components from group A OsbZIPs to OsPYL/RCARs with or without ABA in TGERP. OsbZIP46 induced reporter most strongly among OsbZIPs tested in the presence of ABA. SAPKs could activate the OsbZIP46 even in the ABA independence. Subclass A OsPP2C6 and -8 almost completely inhibited the OsbZIP46 activity in the different degree through the SAPK9. Lastly, OsPYL/RCAR2 and -5 rescued the OsbZIP46 activity in the presence of SAPK9 and OsPP2C6 dependent on ABA concentration and expression level. By using TGERP, we could characterize successfully the effects of ABA dependent gene expression signaling components in rice. In conclusion, TGERP represents very useful technology to study systemic functional genomics in rice or other monocots.

  17. Differences in phosphatidic acid signalling and metabolism between ABA and GA treatments of barley aleurone cells.

    Science.gov (United States)

    Villasuso, Ana Laura; Di Palma, Maria A; Aveldaño, Marta; Pasquaré, Susana J; Racagni, Graciela; Giusto, Norma M; Machado, Estela E

    2013-04-01

    Phosphatidic acid (PA) is the common lipid product in abscisic acid (ABA) and gibberellic acid (GA) response. In this work we investigated the lipid metabolism in response to both hormones. We could detect an in vivo phospholipase D activity (PLD, EC 3.1.4.4). This PLD produced [(32)P]PA (phosphatidic acid) rapidly (minutes) in the presence of ABA, confirming PA involvement in signal transduction, and transiently, indicating rapid PA removal after generation. The presence of PA removal by phosphatidate phosphatase 1 and 2 isoforms (E.C. 3.1.3.4) was verified in isolated aleurone membranes in vitro, the former but not the latter being specifically responsive to the presence of GA or ABA. The in vitro DGPP phosphatase activity was not modified by short time incubation with GA or ABA while the in vitro PA kinase - that allows the production of 18:2-DGPP from 18:2-PA - is stimulated by ABA. The long term effects (24 h) of ABA or GA on lipid and fatty acid composition of aleurone layer cells were then investigated. An increase in PC and, to a lesser extent, in PE levels is the consequence of both hormone treatments. ABA, in aleurone layer cells, specifically activates a PLD whose product, PA, could be the substrate of PAP1 and/or PAK activities. Neither PLD nor PAK activation can be monitored by GA treatment. The increase in PAP1 activity monitored after ABA or GA treatment might participate in the increase in PC level observed after 24 h hormone incubation.

  18. ABA Affects Brassinosteroid-Induced Antioxidant Defense via ZmMAP65-1a in Maize Plants.

    Science.gov (United States)

    Zhu, Yuan; Liu, Weijuan; Sheng, Yu; Zhang, Juan; Chiu, Tsanyu; Yan, Jingwei; Jiang, Mingyi; Tan, Mingpu; Zhang, Aying

    2015-07-01

    Brassinosteroids (BRs) and ABA co-ordinately regulate water deficit tolerance in maize leaves. ZmMAP65-1a, a maize microtubule-associated protein (MAP) which plays an essential role in BR-induced antioxidant defense, has been characterized previously. However, the interactions among BR, ABA and ZmMAP65-1a in water deficit tolerance remain unexplored. In this study, we demonstrated that ABA was required for BR-induced antioxidant defense via ZmMAP65-1a by using biochemical blocking and ABA biosynthetic mutants. The expression of ZmMAP65-1a in maize leaves and mesophyll protoplasts could be increased under polyethylene glycol- (PEG) stimulated water deficit and ABA treatments. Furthermore, the importance of ABA in the early pathway of BR-induced water deficit tolerance was demonstrated by limiting ABA availability. Blocking ABA biosynthesis biochemically or by a null mutation inhibited the downstream gene expression of ZmMAP65-1a and the activity of ZmMAPK5 in the pathway. It also affected the activities of BR-induced antioxidant defense-related enzymes, namely ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), superoxide dismutase (SOD) and NADPH oxidase. In addition, combining results from transiently overexpressed or silenced ZmMAP65-1a in mesophyll protoplasts, we discovered that ZmMAP65-1a mediated the ABA-induced gene expression and activities of APX and SOD. Surprisingly, silencing of ZmMAP65-1a in mesophyll protoplasts did not alter the gene expression of ZmCCaMK and vice versa in response to ABA. Taken together, our data indicate that water deficit-induced ABA is a key mediator in BR-induced antioxidant defense via ZmMAP65-1a in maize.

  19. Release of GTP Exchange Factor Mediated Down-Regulation of Abscisic Acid Signal Transduction through ABA-Induced Rapid Degradation of RopGEFs

    Science.gov (United States)

    Waadt, Rainer; Schroeder, Julian I.

    2016-01-01

    The phytohormone abscisic acid (ABA) is critical to plant development and stress responses. Abiotic stress triggers an ABA signal transduction cascade, which is comprised of the core components PYL/RCAR ABA receptors, PP2C-type protein phosphatases, and protein kinases. Small GTPases of the ROP/RAC family act as negative regulators of ABA signal transduction. However, the mechanisms by which ABA controls the behavior of ROP/RACs have remained unclear. Here, we show that an Arabidopsis guanine nucleotide exchange factor protein RopGEF1 is rapidly sequestered to intracellular particles in response to ABA. GFP-RopGEF1 is sequestered via the endosome-prevacuolar compartment pathway and is degraded. RopGEF1 directly interacts with several clade A PP2C protein phosphatases, including ABI1. Interestingly, RopGEF1 undergoes constitutive degradation in pp2c quadruple abi1/abi2/hab1/pp2ca mutant plants, revealing that active PP2C protein phosphatases protect and stabilize RopGEF1 from ABA-mediated degradation. Interestingly, ABA-mediated degradation of RopGEF1 also plays an important role in ABA-mediated inhibition of lateral root growth. The presented findings point to a PP2C-RopGEF-ROP/RAC control loop model that is proposed to aid in shutting off ABA signal transduction, to counteract leaky ABA signal transduction caused by “monomeric” PYL/RCAR ABA receptors in the absence of stress, and facilitate signaling in response to ABA. PMID:27192441

  20. The NF-YC–RGL2 module integrates GA and ABA signalling to regulate seed germination in Arabidopsis

    Science.gov (United States)

    Liu, Xu; Hu, Pengwei; Huang, Mingkun; Tang, Yang; Li, Yuge; Li, Ling; Hou, Xingliang

    2016-01-01

    The antagonistic crosstalk between gibberellic acid (GA) and abscisic acid (ABA) plays a pivotal role in the modulation of seed germination. However, the molecular mechanism of such phytohormone interaction remains largely elusive. Here we show that three Arabidopsis NUCLEAR FACTOR-Y C (NF-YC) homologues NF-YC3, NF-YC4 and NF-YC9 redundantly modulate GA- and ABA-mediated seed germination. These NF-YCs interact with the DELLA protein RGL2, a key repressor of GA signalling. The NF-YC–RGL2 module targets ABI5, a gene encoding a core component of ABA signalling, via specific CCAAT elements and collectively regulates a set of GA- and ABA-responsive genes, thus controlling germination. These results suggest that the NF-YC–RGL2–ABI5 module integrates GA and ABA signalling pathways during seed germination. PMID:27624486

  1. Chemical inhibition of potato ABA-8'-hydroxylase activity alters in vitro and in vivo ABA metabolism and endogenous ABA levels but does not affect potato microtuber dormancy duration.

    Science.gov (United States)

    Suttle, Jeffrey C; Abrams, Suzanne R; De Stefano-Beltrán, Luis; Huckle, Linda L

    2012-09-01

    The effects of azole-type P450 inhibitors and two metabolism-resistant abscisic acid (ABA) analogues on in vitro ABA-8'-hydroxylase activity, in planta ABA metabolism, endogenous ABA content, and tuber meristem dormancy duration were examined in potato (Solanum tuberosum L. cv. Russet Burbank). When functionally expressed in yeast, three potato CYP707A genes were demonstrated to encode enzymatically active ABA-8'-hydroxylases with micromolar affinities for (+)-ABA. The in vitro activity of the three enzymes was inhibited by the P450 azole-type inhibitors ancymidol, paclobutrazol, diniconazole, and tetcyclasis, and by the 8'-acetylene- and 8'-methylene-ABA analogues, with diniconazole and tetcyclasis being the most potent inhibitors. The in planta metabolism of [(3)H](±)-ABA to phaseic acid and dihydrophaseic acid in tuber meristems was inhibited by diniconazole, tetcyclasis, and to a lesser extent by 8'-acetylene- and 8'-methylene-ABA. Continuous exposure of in vitro generated microtubers to diniconazole resulted in a 2-fold increase in endogenous ABA content and a decline in dihydrophaseic acid content after 9 weeks of development. Similar treatment with 8'-acetylene-ABA had no effects on the endogenous contents of ABA or phaseic acid but reduced the content of dihydrophaseic acid. Tuber meristem dormancy progression was determined ex vitro in control, diniconazole-, and 8'-acetylene-ABA-treated microtubers following harvest. Continuous exposure to diniconazole during microtuber development had no effects on subsequent sprouting at any time point. Continuous exposure to 8'-acetylene-ABA significantly increased the rate of microtuber sprouting. The results indicate that, although a decrease in ABA content is a hallmark of tuber dormancy progression, the decline in ABA levels is not a prerequisite for dormancy exit and the onset of tuber sprouting. PMID:22664582

  2. Type 2C Phosphatase 1 of Artemisia annua L. Is a Negative Regulator of ABA Signaling

    Directory of Open Access Journals (Sweden)

    Fangyuan Zhang

    2014-01-01

    Full Text Available The phytohormone abscisic acid (ABA plays an important role in plant development and environmental stress response. Additionally, ABA also regulates secondary metabolism such as artemisinin in the medicinal plant Artemisia annua L. Although an earlier study showed that ABA receptor, AaPYL9, plays a positive role in ABA-induced artemisinin content improvement, many components in the ABA signaling pathway remain to be elucidated in Artemisia annua L. To get insight of the function of AaPYL9, we isolated and characterized an AaPYL9-interacting partner, AaPP2C1. The coding sequence of AaPP2C1 encodes a deduced protein of 464 amino acids, with all the features of plant type clade A PP2C. Transcriptional analysis showed that the expression level of AaPP2C1 is increased after ABA, salt, and drought treatments. Yeast two-hybrid and bimolecular fluorescence complementation assays (BiFC showed that AaPYL9 interacted with AaPP2C1. The P89S, H116A substitution in AaPYL9 as well as G199D substitution or deletion of the third phosphorylation site-like motif in AaPP2C1 abolished this interaction. Furthermore, constitutive expression of AaPP2C1 conferred ABA insensitivity compared with the wild type. In summary, our data reveals that AaPP2C1 is an AaPYL9-interacting partner and involved in the negative modulation of the ABA signaling pathway in A. annua L.

  3. Isolation and characterization of an osmotic stress and ABA induced histone deacetylase in Arachis hygogaea

    Directory of Open Access Journals (Sweden)

    Su eLiangchen

    2015-07-01

    Full Text Available Histone acetylation, which together with histone methylation regulates gene activity in response to stress, is an important epigenetic modification. There is an increasing research focus on histone acetylation in crops, but there is no information to date in peanut (Arachis hypogaea. We showed that osmotic stress and ABA affect the acetylation of histone H3 loci in peanut seedlings by immunoblotting experiments. Using RNA-seq data for peanut, we found a RPD3/HDA1-like superfamily histone deacetylase (HDAC, termed AhHDA1, whose gene is up-regulated by PEG-induced water limitation and ABA signaling. We isolated and characterized AhHDA1 from A. hypogaea, showing that AhHDA1 is very similar to an Arabidopsis HDAC (AtHDA6 and, in recombinant form, possesses HDAC activity. To understand whether and how osmotic stress and ABA mediate the peanut stress response by epigenetics, the expression of AhHDA1 and stress-responsive genes following treatment with PEG, ABA and the specific HDAC inhibitor trichostatin A (TSA were analysed. AhHDA1 transcript levels were enhanced by all three treatments, as was expression of peanut transcription factor genes, indicating that AhHDA1 might be involved in the epigenetic regulation of stress resistance genes that comprise the responses to osmotic stress and ABA.

  4. Physiological response of exogenous ABA to Tripterygium wilfordii seedlings at low temperature%外源ABA对低温下雷公藤幼苗的生理响应

    Institute of Scientific and Technical Information of China (English)

    黄宇; 王倩; 毕旸; 荣俊冬; 陈礼光; 郑郁善

    2011-01-01

    以1年生的雷公藤扦插苗为试验材料,对其外施浓度分别为5、10、15、20、25 mg·L-1脱落酸(ABA)溶液,以喷施蒸馏水为对照(CK),并进行连续7d的低温胁迫处理.研究低温胁迫下ABA对雷公藤幼苗叶片质膜透性、丙二醛(MDA)、保护酶和脯氨酸等生理生化指标的影响.研究表明,喷施浓度为15-20 mg·L-1的ABA能提高雷公藤幼苗的抗冷性,有效地降低叶片相对电导率和MDA的积累,使雷公藤幼苗体内游离脯氨酸的含量升高,减弱了低温胁迫对超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的影响,当ABA浓度为15 mg·L-1时,其相对电导率和MDA含量最低,分别为45.74%和153.28 nmol·g-1,脯氨酸含量比CK高出72.99 μg·g-1;20 nmg·L-1ABA处理的幼苗冷害程度显著低于其他处理;经ABA处理的SOD活性随胁迫时间的延长呈现明显的“双峰”趋势,POD活性呈现先上升再下降的“单峰”趋势,当ABA浓度为15、20 mg·L-1时,CAT活性呈现“下降—上升一下降”趋势.%One year-old Tripterygiian wilfordii cutting was used as the experiment material. By infliction abscisic acid (ABA) 5, 10, 15, 20, 25 mg-L-1 continuously 7 days under low temperature stress, and with the plant spraying distilled water as control treatment, the effects of ABA on membrane permeability, malondialdehyde ( MDA) content, protective enzyme activity and proline content were studied in T. Wilfordii seedlings leaves. The results showed that spraying 15 - 20 mg ? L'1 ABA improved chilling resistance, effectively reducing relative electrical conductivity and the accumulation of MDA, which increased free proline content of T. Wilfordii cuttings, weakened the effect of low temperature stress on superoxide dismutase ( SOD) , peroxidase ( POD) , catalase* (CAT) enzyme activities. Relajive electrical conductivity and MDA content of 15 mg-L"1 ABA were the lowest, which were 45.74%, and 153.28 nmol-g"1 respectively. Proline

  5. ABA Inducible Rice Protein Phosphatase 2C Confers ABA Insensitivity and Abiotic Stress Tolerance in Arabidopsis

    OpenAIRE

    Singh, Amarjeet; Jha, Saroj K.; Bagri, Jayram; Pandey, Girdhar K.

    2015-01-01

    Arabidopsis PP2C belonging to group A have been extensively worked out and known to negatively regulate ABA signaling. However, rice (Oryza sativa) orthologs of Arabidopsis group A PP2C are scarcely characterized functionally. We have identified a group A PP2C from rice (OsPP108), which is highly inducible under ABA, salt and drought stresses and localized predominantly in the nucleus. Genetic analysis revealed that Arabidopsis plants overexpressing OsPP108 are highly insensitive to ABA and t...

  6. Overexpression of an ABA biosynthesis gene using a stress-inducible promoter enhances drought resistance in petunia

    OpenAIRE

    Estrada-Melo, Alejandro C; Chao,; Reid, Michael S; Cai-Zhong Jiang

    2015-01-01

    The response of plants to drought stress includes reduced transpiration as stomates close in response to increased abscisic acid (ABA) concentrations. Constitutive overexpression of 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthesis, increases drought resistance, but causes negative pleiotropic effects on plant growth and development. We overexpressed the tomato NCED (LeNCED1) in petunia plants under the control of a stress-inducible promoter, rd29A. Under water stress...

  7. Emerging roles of protein kinase CK2 in abscisic acid (ABA signaling

    Directory of Open Access Journals (Sweden)

    Belmiro eVilela

    2015-11-01

    Full Text Available 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.

  8. Root water potential integrates discrete soil physical properties to influence ABA signalling during partial rootzone drying.

    Science.gov (United States)

    Dodd, Ian C; Egea, Gregorio; Watts, Chris W; Whalley, W Richard

    2010-08-01

    To investigate the influence of different growing substrates (two mineral, two organic) on root xylem ABA concentration ([ABA](root)) and the contribution of the drying root system to total sap flow during partial rootzone drying (PRD), sunflower (Helianthus annuus L.) shoots were grafted onto the root systems of two plants grown in separate pots. Sap flow through each hypocotyl was measured below the graft union when one pot ('wet') was watered and other ('dry') was not. Each substrate gave unique relationships between dry pot matric potential (Psi(soil)), volumetric water content ((v)) or penetrometer resistance (Q) and either the fraction of photoperiod sap flow from roots in drying soil or [ABA](root). However, decreased relative sap flow, and increased [ABA](root), from roots in drying soil varied with root water potential (Psi(root)) more similarly across a range of substrates. The gradient between Psi(soil) and Psi(root) was greater in substrates with high sand or peat proportions, which may have contributed to a more sensitive response of [ABA](root) to Psi(soil) in these substrates. Whole plant transpiration was most closely correlated with the mean Psi(soil) of both pots, and then with detached leaf xylem ABA concentration. Although Psi(root) best predicted decreased relative sap flow, and increased [ABA](root), from roots in drying soil across a range of substrates, the inaccessibility of this variable in field studies requires a better understanding of how measurable soil variables (Psi(soil), (v), Q) affect Psi(root). PMID:20591896

  9. Roles of a sustained activation of NCED3 and the synergistic regulation of ABA biosynthesis and catabolism in ABA signal production in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    REN HuiBo; JIA WenSuo; FAN YiJian; GAO ZhiHui; WEI KaiFa; LI GuiFen; LIU Jing; CHEN Lin; LI BingBing; HU JianFang

    2007-01-01

    ABA, acting as a stress signal, plays crucial roles in plant resistance to water stress. Because ABA signal production is based on ABA biosynthesis, the regulation of NCED, a key enzyme in the ABA biosynthesis pathway, is normally thought of as the sole factor controlling ABA signal production. Here we demonstrate that ABA catabolism in combination with a synergistic regulation of ABA biosynthesis plays a crucial role in governing ABA signal production. Water stress induced a significant accumulation of ABA, which exhibited different patterns in detached and attached leaves. ABA catabolism followed a temporal trend of exponential decay for both basic and stress ABA, and there was little difference in the catabolic half-lives of basic ABA and stress ABA. Thus, the absolute rate of ABA catabolism, i.e. the amount of ABA catabolized per unit time, increases with increased ABA accumulation. From the dynamic processes of ABA biosynthesis and catabolism, it can be inferred that stress ABA accumulation may be governed by a synergistic regulation of all the steps in the ABA biosynthesis pathway. Moreover, to maintain an elevated level of stress ABA sustained activation of NCED3 should be required. This inference was supported by further findings that the genes encoding major enzymes in the ABA biosynthesis pathway, e.g. NCED3, AAO3 and ABA3 were all activated by water stress, and with ABA accumulation progressing, the expressions of NCED3, AAO3 and ABA3 remained activated. Data on ABA catabolism and gene expression jointly indicate that ABA signal production is controlled by a sustained activation of NCED3 and the synergistic regulation of ABA biosynthesis and catabolism.

  10. New fava bean guard cell signaling mutant impaired in ABA-induced stomatal closure.

    Science.gov (United States)

    Iwai, Sumio; Shimomura, Naoki; Nakashima, Atsushi; Etoh, Takeomi

    2003-09-01

    We isolated a mutant from Vicia faba L. cv. House Ryousai. It wilts easily under strong light and high temperature conditions, suggesting that its stomatal movement may be disturbed. We determined responses of mutant guard cells to some environmental stimuli. Mutant guard cells demonstrated an impaired ability to respond to ABA in 0.1 mM CaCl(2) and stomata did not close in the presence of up to 1 mM ABA, whereas wild-type stomata closed when exposed to 10 micro M ABA. Elevating external Ca(2+) caused a similar degree of stomatal closure in the wild type and the mutant. A high concentration of CO(2) (700 micro l liter(-1)) induced stomatal closure in the wild type, but not in the mutant. On the basis of these results, we propose the working hypothesis that the mutation occurs in the region downstream of CO(2) and ABA sensing and in the region upstream of Ca(2+) elevation. The mutant is named fia (fava bean impaired in ABA-induced stomatal closure). PMID:14519772

  11. An ABA-based Intervention Package for Treating the Inappropriate Use of a Communication Device Within Autistic Populations

    OpenAIRE

    Virge Connery

    2013-01-01

    The principles of applied behaviour analysis (ABA) are widely used with autistic populations in managing challenging behaviour. The following paper will review supporting literature for creating a treatment package for targeting the misuse of a communication device in brief detail by using key elements in ABA. It will examine various types of attention (or response) that may reinforce the problem behaviour, as well as intervention methods, such as functional communication training and noncont...

  12. Ordering phenomena in ABA triblock copolymer gels

    DEFF Research Database (Denmark)

    Reynders, K.; Mischenko, N.; Kleppinger, R.;

    1997-01-01

    Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network). The lat......Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network...... crystalline lattice with close-packed spheres or with cubic (presumably BCC) equilibrium morphology. The appearance of the latter is never detected in the gels with a stretched conformation of the midblock....

  13. A Portable Application Supporting ABA Intervention

    OpenAIRE

    Artoni, Silvia; Buzzi, Maria Claudia; Buzzi, Marina; Fenili, Claudia; Mencarini, Simona; Senette, Caterina; Leporini, Barbara

    2013-01-01

    Abstract Purpose - Applied Behavior Analysis (ABA) is a scientific method for modelling human behavior, successfully applied in the context of autism. Recording and sharing measurable data (on the subjects' performance) between caregivers guarantees consistency of learning programs and allows monitoring the learning enhancement of the subject. Data are usually recorded on paper and partially ?copied in an electronic format later, which requires considerable effort and is subject to error. In ...

  14. ABA inducible rice protein phosphatase 2C confers ABA insensitivity and abiotic stress tolerance in Arabidopsis.

    Science.gov (United States)

    Singh, Amarjeet; Jha, Saroj K; Bagri, Jayram; Pandey, Girdhar K

    2015-01-01

    Arabidopsis PP2C belonging to group A have been extensively worked out and known to negatively regulate ABA signaling. However, rice (Oryza sativa) orthologs of Arabidopsis group A PP2C are scarcely characterized functionally. We have identified a group A PP2C from rice (OsPP108), which is highly inducible under ABA, salt and drought stresses and localized predominantly in the nucleus. Genetic analysis revealed that Arabidopsis plants overexpressing OsPP108 are highly insensitive to ABA and tolerant to high salt and mannitol stresses during seed germination, root growth and overall seedling growth. At adult stage, OsPP108 overexpression leads to high tolerance to salt, mannitol and drought stresses with far better physiological parameters such as water loss, fresh weight, chlorophyll content and photosynthetic potential (Fv/Fm) in transgenic Arabidopsis plants. Expression profile of various stress marker genes in OsPP108 overexpressing plants revealed interplay of ABA dependent and independent pathway for abiotic stress tolerance. Overall, this study has identified a potential rice group A PP2C, which regulates ABA signaling negatively and abiotic stress signaling positively. Transgenic rice plants overexpressing this gene might provide an answer to the problem of low crop yield and productivity during adverse environmental conditions. PMID:25886365

  15. ABA inducible rice protein phosphatase 2C confers ABA insensitivity and abiotic stress tolerance in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Amarjeet Singh

    Full Text Available Arabidopsis PP2C belonging to group A have been extensively worked out and known to negatively regulate ABA signaling. However, rice (Oryza sativa orthologs of Arabidopsis group A PP2C are scarcely characterized functionally. We have identified a group A PP2C from rice (OsPP108, which is highly inducible under ABA, salt and drought stresses and localized predominantly in the nucleus. Genetic analysis revealed that Arabidopsis plants overexpressing OsPP108 are highly insensitive to ABA and tolerant to high salt and mannitol stresses during seed germination, root growth and overall seedling growth. At adult stage, OsPP108 overexpression leads to high tolerance to salt, mannitol and drought stresses with far better physiological parameters such as water loss, fresh weight, chlorophyll content and photosynthetic potential (Fv/Fm in transgenic Arabidopsis plants. Expression profile of various stress marker genes in OsPP108 overexpressing plants revealed interplay of ABA dependent and independent pathway for abiotic stress tolerance. Overall, this study has identified a potential rice group A PP2C, which regulates ABA signaling negatively and abiotic stress signaling positively. Transgenic rice plants overexpressing this gene might provide an answer to the problem of low crop yield and productivity during adverse environmental conditions.

  16. Stomatal malfunctioning under low VPD conditions: induced by alterations in stomatal morphology and leaf anatomy or in the ABA signaling?

    Science.gov (United States)

    Aliniaeifard, Sasan; Malcolm Matamoros, Priscila; van Meeteren, Uulke

    2014-12-01

    Exposing plants to low VPD reduces leaf capacity to maintain adequate water status thereafter. To find the impact of VPD on functioning of stomata, stomatal morphology and leaf anatomy, fava bean plants were grown at low (L, 0.23 kPa) or moderate (M, 1.17 kPa) VPDs and some plants that developed their leaves at moderate VPD were then transferred for 4 days to low VPD (M→L). Part of the M→L-plants were sprayed with ABA (abscisic acid) during exposure to L. L-plants showed bigger stomata, larger pore area, thinner leaves and less spongy cells compared with M-plants. Stomatal morphology (except aperture) and leaf anatomy of the M→L-plants were almost similar to the M-plants, while their transpiration rate and stomatal conductance were identical to that of L-plants. The stomatal response to ABA was lost in L-plants, but also after 1-day exposure of M-plants to low VPD. The level of foliar ABA sharply decreased within 1-day exposure to L, while the level of ABA-GE (ABA-glucose ester) was not affected. Spraying ABA during the exposure to L prevented loss of stomatal closing response thereafter. The effect of low VPD was largely depending on exposure time: the stomatal responsiveness to ABA was lost after 1-day exposure to low VPD, while the responsiveness to desiccation was gradually lost during 4-day exposure to low VPD. Leaf anatomical and stomatal morphological alterations due to low VPD were not the main cause of loss of stomatal closure response to closing stimuli.

  17. Mutations in the Arabidopsis Lst8 and Raptor genes encoding partners of the TOR complex, or inhibition of TOR activity decrease abscisic acid (ABA) synthesis.

    Science.gov (United States)

    Kravchenko, Alena; Citerne, Sylvie; Jéhanno, Isabelle; Bersimbaev, Rakhmetkazhi I; Veit, Bruce; Meyer, Christian; Leprince, Anne-Sophie

    2015-11-27

    The Target of Rapamycin (TOR) kinase regulates essential processes in plant growth and development by modulation of metabolism and translation in response to environmental signals. In this study, we show that abscisic acid (ABA) metabolism is also regulated by the TOR kinase. Indeed ABA hormone level strongly decreases in Lst8-1 and Raptor3g mutant lines as well as in wild-type (WT) Arabidopsis plants treated with AZD-8055, a TOR inhibitor. However the growth and germination of these lines are more sensitive to exogenous ABA. The diminished ABA hormone accumulation is correlated with lower transcript levels of ZEP, NCED3 and AAO3 biosynthetic enzymes, and higher transcript amount of the CYP707A2 gene encoding a key-enzyme in abscisic acid catabolism. These results suggest that the TOR signaling pathway is implicated in the regulation of ABA accumulation in Arabidopsis.

  18. The GCR2 gene family is not required for ABA control of seed germination and early seedling development in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Jianjun Guo

    Full Text Available BACKGROUND: The plant hormone abscisic acid (ABA regulates diverse processes of plant growth and development. It has recently been proposed that GCR2 functions as a G-protein-coupled receptor (GPCR for ABA. However, the structural relationships and functionality of GCR2 have been challenged by several independent studies. A central question in this controversy is whether gcr2 mutants are insensitive to ABA, because gcr2 mutants were shown to display reduced sensitivity to ABA under one experimental condition (e.g. 22 degrees C, continuous white light with 150 micromol m(-2 s(-1 but were shown to display wild-type sensitivity under another slightly different condition (e.g. 23 degrees C, 14/10 hr photoperiod with 120 micromol m(-2 s(-1. It has been hypothesized that gcr2 appears only weakly insensitive to ABA because two other GCR2-like genes in Arabidopsis, GCL1 and GCL2, compensate for the loss of function of GCR2. PRINCIPAL FINDINGS: In order to test this hypothesis, we isolated a putative loss-of-function allele of GCL2, and then generated all possible combinations of mutations in each member of the GCR2 gene family. We found that all double mutants, including gcr2 gcl1, gcr2 gcl2, gcl1 gcl2, as well as the gcr2 gcl1 gcl2 triple mutant displayed wild-type sensitivity to ABA in seed germination and early seedling development assays, demonstrating that the GCR2 gene family is not required for ABA responses in these processes. CONCLUSION: These results provide compelling genetic evidence that GCR2 is unlikely to act as a receptor for ABA in the context of either seed germination or early seedling development.

  19. Overexpression of Arachis hypogaea AREB1 Gene Enhances Drought Tolerance by Modulating ROS Scavenging and Maintaining Endogenous ABA Content

    Directory of Open Access Journals (Sweden)

    Ling Li

    2013-06-01

    Full Text Available AhAREB1 (Arachis hypogaea Abscisic-acid Response Element Binding Protein 1 is a member of the basic domain leucine zipper (bZIP-type transcription factor in peanut. Previously, we found that expression of AhAREB1 was specifically induced by abscisic acid (ABA, dehydration and drought. To understand the drought defense mechanism regulated by AhAREB1, transgenic Arabidopsis overexpressing AhAREB1 was conducted in wild-type (WT, and a complementation experiment was employed to ABA non-sensitivity mutant abi5 (abscisic acid-insensitive 5. Constitutive expression of AhAREB1 confers water stress tolerance and is highly sensitive to exogenous ABA. Microarray and further real-time PCR analysis revealed that drought stress, reactive oxygen species (ROS scavenging, ABA synthesis/metabolism-related genes and others were regulated in transgenic Arabidopsis overexpressing AhAREB1. Accordingly, low level of ROS, but higher ABA content was detected in the transgenic Arabidopsis plants’ overexpression of AhAREB1. Taken together, it was concluded that AhAREB1 modulates ROS accumulation and endogenous ABA level to improve drought tolerance in transgenic Arabidopsis.

  20. ABA and cytokinins: challenge and opportunity for plant stress research.

    Science.gov (United States)

    Verslues, Paul E

    2016-08-01

    Accumulation of the stress hormone abscisic acid (ABA) induces many cellular mechanisms associated with drought resistance. Recent years have seen a rapid advance in our knowledge of how increased ABA levels are perceived by ABA receptors, particularly the PYL/RCAR receptors, but there has been relatively less new information about how ABA accumulation is controlled and matched to stress severity. ABA synthesis and catabolism, conjugation and deconjugation to glucose, and ABA transport all are involved in controlling ABA levels. This highly buffered system of ABA metabolism represents both a challenge and opportunity in developing a mechanistic understanding of how plants detect and respond to drought. Recent data have also shown that direct manipulation of cytokinin levels in transgenic plants has dramatic effect on drought phenotypes and prompted new interest in the role of cytokinins and cytokinin signaling in drought. Both ABA and cytokinins will continue to be major foci of drought research but likely with different trajectories both in terms of basic research and in translational research aimed at increasing plant performance during drought. PMID:26910054

  1. La fortaleza del abañil

    OpenAIRE

    SÁNCHEZ TOLEDO, MARTA

    2011-01-01

    Trabajo científico técnico.La presente investigación analiza diversos aspectos laborales de los trabajadores de la albañilería desde su propio punto de vista, siguiendo un enfoque cualitativo. Describiéndose la albañilería como el arte de construir edificios utilizando materiales que ofrece la naturaleza o materiales industrializados. La investigación se centra en el municipio de Villarrobledo. Sánchez Toledo, M. (2011). La fortaleza del abañil. http://hdl.handle.net/10251/11601. Arc...

  2. A 14-3-3 Family Protein from Wild Soybean (Glycine Soja Regulates ABA Sensitivity in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Xiaoli Sun

    Full Text Available It is widely accepted that the 14-3-3 family proteins are key regulators of multiple stress signal transduction cascades. By conducting genome-wide analysis, researchers have identified the soybean 14-3-3 family proteins; however, until now, there is still no direct genetic evidence showing the involvement of soybean 14-3-3s in ABA responses. Hence, in this study, based on the latest Glycine max genome on Phytozome v10.3, we initially analyzed the evolutionary relationship, genome organization, gene structure and duplication, and three-dimensional structure of soybean 14-3-3 family proteins systematically. Our results suggested that soybean 14-3-3 family was highly evolutionary conserved and possessed segmental duplication in evolution. Then, based on our previous functional characterization of a Glycine soja 14-3-3 protein GsGF14o in drought stress responses, we further investigated the expression characteristics of GsGF14o in detail, and demonstrated its positive roles in ABA sensitivity. Quantitative real-time PCR analyses in Glycine soja seedlings and GUS activity assays in PGsGF14O:GUS transgenic Arabidopsis showed that GsGF14o expression was moderately and rapidly induced by ABA treatment. As expected, GsGF14o overexpression in Arabidopsis augmented the ABA inhibition of seed germination and seedling growth, promoted the ABA induced stomata closure, and up-regulated the expression levels of ABA induced genes. Moreover, through yeast two hybrid analyses, we further demonstrated that GsGF14o physically interacted with the AREB/ABF transcription factors in yeast cells. Taken together, results presented in this study strongly suggested that GsGF14o played an important role in regulation of ABA sensitivity in Arabidopsis.

  3. A 14-3-3 Family Protein from Wild Soybean (Glycine Soja) Regulates ABA Sensitivity in Arabidopsis.

    Science.gov (United States)

    Sun, Xiaoli; Sun, Mingzhe; Jia, Bowei; Chen, Chao; Qin, Zhiwei; Yang, Kejun; Shen, Yang; Meiping, Zhang; Mingyang, Cong; Zhu, Yanming

    2015-01-01

    It is widely accepted that the 14-3-3 family proteins are key regulators of multiple stress signal transduction cascades. By conducting genome-wide analysis, researchers have identified the soybean 14-3-3 family proteins; however, until now, there is still no direct genetic evidence showing the involvement of soybean 14-3-3s in ABA responses. Hence, in this study, based on the latest Glycine max genome on Phytozome v10.3, we initially analyzed the evolutionary relationship, genome organization, gene structure and duplication, and three-dimensional structure of soybean 14-3-3 family proteins systematically. Our results suggested that soybean 14-3-3 family was highly evolutionary conserved and possessed segmental duplication in evolution. Then, based on our previous functional characterization of a Glycine soja 14-3-3 protein GsGF14o in drought stress responses, we further investigated the expression characteristics of GsGF14o in detail, and demonstrated its positive roles in ABA sensitivity. Quantitative real-time PCR analyses in Glycine soja seedlings and GUS activity assays in PGsGF14O:GUS transgenic Arabidopsis showed that GsGF14o expression was moderately and rapidly induced by ABA treatment. As expected, GsGF14o overexpression in Arabidopsis augmented the ABA inhibition of seed germination and seedling growth, promoted the ABA induced stomata closure, and up-regulated the expression levels of ABA induced genes. Moreover, through yeast two hybrid analyses, we further demonstrated that GsGF14o physically interacted with the AREB/ABF transcription factors in yeast cells. Taken together, results presented in this study strongly suggested that GsGF14o played an important role in regulation of ABA sensitivity in Arabidopsis.

  4. Overexpression of an ABA biosynthesis gene using a stress-inducible promoter enhances drought resistance in petunia.

    Science.gov (United States)

    Estrada-Melo, Alejandro C; Chao; Reid, Michael S; Jiang, Cai-Zhong

    2015-01-01

    The response of plants to drought stress includes reduced transpiration as stomates close in response to increased abscisic acid (ABA) concentrations. Constitutive overexpression of 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthesis, increases drought resistance, but causes negative pleiotropic effects on plant growth and development. We overexpressed the tomato NCED (LeNCED1) in petunia plants under the control of a stress-inducible promoter, rd29A. Under water stress, the transgenic plants had increased transcripts of NCED mRNA, elevated leaf ABA concentrations, increased concentrations of proline, and a significant increase in drought resistance. The transgenic plants also displayed the expected decreases in stomatal conductance, transpiration, and photosynthesis. After 14 days without water, the control plants were dead, but the transgenic plants, though wilted, recovered fully when re-watered. Well-watered transgenic plants grew like non-transformed control plants and there was no effect of the transgene on seed dormancy. PMID:26504568

  5. CONCEPTOS GENERALES SOBRE ABA EN NIÑOS CON TRASTORNO DEL ESPECTRO AUTISTA General concepts concerning applied behaviour analysis (ABA in children suffering autistic spectrum disorders (ASD

    Directory of Open Access Journals (Sweden)

    Sandra Elizabeth Piñeros-Ortiz

    2012-03-01

    Full Text Available Los trastornos del espectro autista (TEA son entidades que generan discapacidad. Diversas intervenciones psicofarmacológicas y psicosociales modulan algunas de las alteraciones comportamentales asociadas y mejoran la calidad de vida de las personas afectadas y de sus cuidadores. La terapia ABA es una de las intervenciones psicosociales más conocidas y utilizada en población con TEA. Mediante de la formulación de preguntas clave y sus respuestas, este artículo realiza una breve descripción de los aspectos históricos, las principales características y los fundamentos teóricos del ABA. Se discuten los resultados de diversos estudios que señalan las limitaciones metodológicas de las investigaciones sobre la efectividad de esta terapia y sus implicaciones para la práctica clínica.Autistic spectrum disorders (ASD cause disability. Psychopharmacological and psychosocial interventions modulate some of the associated behavioural alterations and improve the quality of life for those affected and the people caring for them. Applied behaviour analysis (ABA therapy is one of the most well-known psychosocial interventions and is used with populations suffering ASD. This article gives a brief description of the historical aspects, the main characteristics and theoretical foundations regarding applied behaviour analysis (ABA by formulating key questions and their (expected responses. The results of some pertinent studies are discussed, pointing out the methodological limitations of research into the effectiveness of this therapy and its implications for clinical practice.

  6. Expression of ABA synthesis and metabolism genes under different irrigation strategies and atmospheric VPDs is associated with stomatal conductance in grapevine (Vitis vinifera L. cv Cabernet Sauvignon).

    Science.gov (United States)

    Speirs, Jim; Binney, Allan; Collins, Marisa; Edwards, Everard; Loveys, Brian

    2013-04-01

    The influence of different levels of irrigation and of variation in atmospheric vapour pressure deficit (VPD) on the synthesis, metabolism, and transport of abscisic acid (ABA) and the effects on stomatal conductance were examined in field-grown Cabernet Sauvignon grapevines. Xylem sap, leaf tissue, and root tissue were collected at regular intervals during two seasons in conjunction with measurements of leaf water potential (Ψleaf) and stomatal conductance (gs). The different irrigation levels significantly altered the Ψleaf and gs of the vines across both seasons. ABA abundance in the xylem sap was correlated with gs. The expression of genes associated with ABA synthesis, NCED1 and NCED2, was higher in the roots than in the leaves throughout and highest in the roots in mid January, a time when soil moisture declined and VPD was at its highest. Their expression in roots was also inversely related to the levels of irrigation and correlated with ABA abundance in the roots, xylem sap, and leaves. Three genes encoding ABA 8'-hydroxylases were isolated and their identities confirmed by expression in yeast cells. The expression of one of these, Hyd1, was elevated in leaves when VPD was below 2.0-2.5 kPa and minimal at higher VPD levels. The results provide evidence that ABA plays an important role in linking stomatal response to soil moisture status and that changes in ABA catabolism at or near its site of action allows optimization of gas exchange to current environmental conditions. PMID:23630325

  7. The evolution of the role of ABA in the regulation of water-use efficiency: From biochemical mechanisms to stomatal conductance.

    Science.gov (United States)

    Negin, Boaz; Moshelion, Menachem

    2016-10-01

    Abscisic acid is found in a wide variety of organisms. In the plant kingdom, ABA's role in mediating responses to abiotic stress has been conserved and enhanced throughout evolution. The emergence of plants to terrestrial environments required the development of mechanisms to cope with ongoing and severe abiotic stress such as drought and rapid changes in humidity and temperature. The common understanding is that terrestrial plants evolved strategies ranging from desiccation-tolerance mechanisms (mosses) to drought tolerance (CAM plants), to better exploit different ecological niches. In between these divergent water regulation strategies, ABA plays a significant role in managing plants' adaptation to new environments by optimizing water-use efficiency (WUE) under particular environmental conditions. ABA plays some very different roles in the regulation of WUE. ABA's role in the regulation of guard cells and transpiration has yielded a wide variety of WUE-regulation mechanisms, ranging from no sensitivity (ferns) to low sensitivity (anisohydric behavior) to hypersensitivity to ABA (isohydric behavior and putatively CAM plants). ABA also plays a role in the regulation of non-stomatal, biochemical mechanisms of WUE regulation. In angiosperms, this includes the control of osmotic adjustment and morphological changes, including changes in leaf size, stomatal density, stomatal size and root development. Under severe stress, ABA also appears to initiate leaf senescence via transcriptional regulation, to directly inhibit photosynthesis. PMID:27593466

  8. SlSOM inhibits seed germination by regulating the expression of ABA/GA metabolic genes and SlABI5 in Solanum lycopersicum

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-chun; GAO Yong-feng; ZHANG Ning; LI Hui-rong; YANG Shu-zhang; LIU Yong-sheng

    2015-01-01

    SOM encodes a nucleus-localized CCCH-type zinc finger protein and negatively regulates seed germination in Arabidopsis thaliana. We have previously demonstrated that ectopic expression of SlABI3, an important transcription factor in abscisic acid (ABA) signaling pathway, resulted in alteration of SlSOM expression patterns in both leaf and seed of tomato. In this study, we aimed to elucidate the function of tomato SlSOM in regarding to seed germination and seedling development. Here, we constructed SlSOM over-expression vector pBI121-SOM driven by CaMV 35S promoter, and the recombinant plasmid was incorporated into wild-type tomato by the method of Agrobacterium tumefaciens-mediated transformation. The result showed that over-expression of SlSOM conferred enhanced responses to exogenous ABA application during seed germination and seedling development. In addition, ectopic expression of SlSOM resulted in the alteration of expression level of ABA/GA (gibberel ins) metabolic genes, such as SlABA1, SlCYP707A1, SlGA3ox2, and SlGA2ox4, in both leaf and seed. The ABA anabolic gene SlABA1 and the GA catabolic gene SlGA2ox4 were up-regulated while the ABA catabolic gene SlCYP707A1 and the GA anabolic gene SlGA3ox2 were down-regulated. Compared to wild type, the expression level of SlABI5 was increased by about 40–50%in transgenic seeds while adding exogenous ABA treatment. These results support the notion that SlSOM inhibits seed germination by regulating ABA/GA metabolic genes and SlABI5 expression in Solanum lycopersicum.

  9. Osmotic stress represses strigolactone biosynthesis in Lotus japonicus roots: exploring the interaction between strigolactones and ABA under abiotic stress

    KAUST Repository

    Liu, Junwei

    2015-02-26

    Main conclusion: Strigolactone changes and cross talk with ABA unveil a picture of root-specific hormonal dynamics under stress.Abstract: Strigolactones (SLs) are carotenoid-derived hormones influencing diverse aspects of development and communication with (micro)organisms, and proposed as mediators of environmental stimuli in resource allocation processes; to contribute to adaptive adjustments, therefore, their pathway must be responsive to environmental cues. To investigate the relationship between SLs and abiotic stress in Lotus japonicus, we compared wild-type and SL-depleted plants, and studied SL metabolism in roots stressed osmotically and/or phosphate starved. SL-depleted plants showed increased stomatal conductance, both under normal and stress conditions, and impaired resistance to drought associated with slower stomatal closure in response to abscisic acid (ABA). This confirms that SLs contribute to drought resistance in species other than Arabidopsis. However, we also observed that osmotic stress rapidly and strongly decreased SL concentration in tissues and exudates of wild-type Lotus roots, by acting on the transcription of biosynthetic and transporter-encoding genes and independently of phosphate abundance. Pre-treatment with exogenous SLs inhibited the osmotic stress-induced ABA increase in wild-type roots and down-regulated the transcription of the ABA biosynthetic gene LjNCED2. We propose that a transcriptionally regulated, early SL decrease under osmotic stress is needed (but not sufficient) to allow the physiological increase of ABA in roots. This work shows that SL metabolism and effects on ABA are seemingly opposite in roots and shoots under stress.

  10. The Top 10 Reasons Children With Autism Deserve ABA

    OpenAIRE

    Walsh, Mary Beth

    2011-01-01

    We who advocate for applied behavior analysis (ABA) for children with autism spectrum disorders often construct our arguments based on the scientific evidence. However, the audience that most needs to hear this argument, that is, the parents of children, especially very young children, diagnosed with autism, may not be convinced by the science alone. This essay attempts to make the case for the multiple benefits of ABA intervention through the use of humor and anecdotes couched in a “Top Ten ...

  11. Roles for farnesol and ABA in Arabidopsis flower development

    OpenAIRE

    Fitzpatrick, A. Heather; Shrestha, Nisha; Bhandari, Jayaram; Crowell, Dring N

    2011-01-01

    The Arabidopsis FOLK (At5g58560) gene encodes farnesol kinase, which phosphorylates farnesol to farnesyl phosphate. Loss-of-function mutations in the FOLK gene are associated with enhanced sensitivity to abscisic acid (ABA), suggesting that FOLK negatively regulates ABA signaling. Moreover, folk flowers develop supernumerary carpels under water stress, providing evidence for a molecular link between farnesol metabolism, abiotic stress signaling and flower development. Here, we show that farne...

  12. An ABA-mimicking ligand that reduces water loss and promotes drought resistance in plants

    OpenAIRE

    Cao, Minjie; Liu, Xue; Yan ZHANG; Xue, Xiaoqian; Zhou, X. Edward; Melcher, Karsten; Gao, Pan; Wang, Fuxing; Zeng, Liang; Zhao, Yang; Deng, Pan; Zhong, Dafang; Zhu, Jian-Kang; Xu, H. Eric; Xu, Yong

    2013-01-01

    Abscisic acid (ABA) is the most important hormone for plants to resist drought and other abiotic stresses. ABA binds directly to the PYR/PYL family of ABA receptors, resulting in inhibition of type 2C phosphatases (PP2C) and activation of downstream ABA signaling. It is envisioned that intervention of ABA signaling by small molecules could help plants to overcome abiotic stresses such as drought, cold and soil salinity. However, chemical instability and rapid catabolism by plant enzymes limit...

  13. Isolation of a wheat (Triticum aestivum L.) mutant in ABA 8′-hydroxylase gene: effect of reduced ABA catabolism on germination inhibition under field condition

    Science.gov (United States)

    Chono, Makiko; Matsunaka, Hitoshi; Seki, Masako; Fujita, Masaya; Kiribuchi-Otobe, Chikako; Oda, Shunsuke; Kojima, Hisayo; Kobayashi, Daisuke; Kawakami, Naoto

    2013-01-01

    Pre-harvest sprouting, the germination of mature seeds on the mother plant under moist condition, is a serious problem in cereals. To investigate the effect of reduced abscisic acid (ABA) catabolism on germination in hexaploid wheat (Triticum aestivum L.), we cloned the wheat ABA 8′-hydroxyase gene which was highly expressed during seed development (TaABA8′OH1) and screened for mutations that lead to reduced ABA catabolism. In a screen for natural variation, one insertion mutation in exon 5 of TaABA8′OH1 on the D genome (TaABA8′OH1-D) was identified in Japanese cultivars including ‘Tamaizumi’. However, a single mutation in TaABA8′OH1-D had no clear effect on germination inhibition in double haploid lines. In a screen for a mutation, one deletion mutant lacking the entire TaABA8′OH1 on the A genome (TaABA8′OH1-A), TM1833, was identified from gamma-ray irradiation lines of ‘Tamaizumi’. TM1833 (a double mutant in TaABA8′OH1-A and TaABA8′OH1-D) showed lower TaABA8′OH1 expression, higher ABA content in embryos during seed development under field condition and lower germination than those in ‘Tamaizumi’ (a single mutant in TaABA8′OH1-D). These results indicate that reduced ABA catabolism through mutations in TaABA8′OH1 may be effective in germination inhibition in field-grown wheat. PMID:23641187

  14. Isolation of a wheat (Triticum aestivum L.) mutant in ABA 8'-hydroxylase gene: effect of reduced ABA catabolism on germination inhibition under field condition.

    Science.gov (United States)

    Chono, Makiko; Matsunaka, Hitoshi; Seki, Masako; Fujita, Masaya; Kiribuchi-Otobe, Chikako; Oda, Shunsuke; Kojima, Hisayo; Kobayashi, Daisuke; Kawakami, Naoto

    2013-03-01

    Pre-harvest sprouting, the germination of mature seeds on the mother plant under moist condition, is a serious problem in cereals. To investigate the effect of reduced abscisic acid (ABA) catabolism on germination in hexaploid wheat (Triticum aestivum L.), we cloned the wheat ABA 8'-hydroxyase gene which was highly expressed during seed development (TaABA8'OH1) and screened for mutations that lead to reduced ABA catabolism. In a screen for natural variation, one insertion mutation in exon 5 of TaABA8'OH1 on the D genome (TaABA8'OH1-D) was identified in Japanese cultivars including 'Tamaizumi'. However, a single mutation in TaABA8'OH1-D had no clear effect on germination inhibition in double haploid lines. In a screen for a mutation, one deletion mutant lacking the entire TaABA8'OH1 on the A genome (TaABA8'OH1-A), TM1833, was identified from gamma-ray irradiation lines of 'Tamaizumi'. TM1833 (a double mutant in TaABA8'OH1-A and TaABA8'OH1-D) showed lower TaABA8'OH1 expression, higher ABA content in embryos during seed development under field condition and lower germination than those in 'Tamaizumi' (a single mutant in TaABA8'OH1-D). These results indicate that reduced ABA catabolism through mutations in TaABA8'OH1 may be effective in germination inhibition in field-grown wheat.

  15. cGMP-dependent ABA-induced stomatal closure in the ABA-insensitive Arabidopsis mutant abi1-1.

    Science.gov (United States)

    Dubovskaya, Lyudmila V; Bakakina, Yulia S; Kolesneva, Ekaterina V; Sodel, Dmitry L; McAinsh, Martin R; Hetherington, Alistair M; Volotovski, Igor D

    2011-07-01

    • The drought hormone abscisic acid (ABA) is widely known to produce reductions in stomatal aperture in guard cells. The second messenger cyclic guanosine 3', 5'-monophosphate (cGMP) is thought to form part of the signalling pathway by which ABA induces stomatal closure. • We have examined the signalling events during cGMP-dependent ABA-induced stomatal closure in wild-type Arabidopsis plants and plants of the ABA-insensitive Arabidopsis mutant abi1-1. • We show that cGMP acts downstream of hydrogen peroxide (H(2) O(2) ) and nitric oxide (NO) in the signalling pathway by which ABA induces stomatal closure. H(2) O(2) - and NO-induced increases in the cytosolic free calcium concentration ([Ca(2+) ](cyt) ) were cGMP-dependent, positioning cGMP upstream of [Ca(2+) ](cyt) , and involved the action of the type 2C protein phosphatase ABI1. Increases in cGMP were mediated through the stimulation of guanylyl cyclase by H(2) O(2) and NO. We identify nucleoside diphosphate kinase as a new cGMP target protein in Arabidopsis. • This study positions cGMP downstream of ABA-induced changes in H(2) O(2) and NO, and upstream of increases in [Ca(2+) ](cyt) in the signalling pathway leading to stomatal closure.

  16. Magnetic oscillation of optical phonon in ABA- and ABC-stacked trilayer graphene

    Science.gov (United States)

    Cong, Chunxiao; Jung, Jeil; Cao, Bingchen; Qiu, Caiyu; Shen, Xiaonan; Ferreira, Aires; Adam, Shaffique; Yu, Ting

    2015-06-01

    We present a comparative measurement of the G -peak oscillations of phonon frequency, Raman intensity, and linewidth in the magneto-Raman scattering of optical E2 g phonons in mechanically exfoliated ABA- and ABC-stacked trilayer graphene (TLG). Whereas in ABA-stacked TLG, we observe magnetophonon oscillations consistent with single-bilayer chiral band doublets, the features are flat for ABC-stacked TLG up to magnetic fields of 9 T. This suppression can be attributed to the enhancement of band chirality that compactifies the spectrum of Landau levels and modifies the magnetophonon resonance properties. The drastically different coupling behavior between the electronic excitations and the E2 g phonons in ABA- and ABC-stacked TLG reflects their different electronic band structures and the electronic Landau level transitions and thus can be another way to determine the stacking orders and to probe the stacking-order-dependent electronic structures. In addition, the sensitivity of the magneto-Raman scattering to the particular stacking order in few-layer graphene highlights the important role of interlayer coupling in modifying the optical response properties in van der Waals layered materials.

  17. ARA-aldehyde and ABA-trans-diol in apple fruits

    Energy Technology Data Exchange (ETDEWEB)

    Rock, C.D.; Zeevaart, J.A.D. (Michigan State Univ., East Lansing (USA))

    1989-04-01

    We have isolated ABA-aldehyde and ABA-t-diol from postharvest apple fruits, cv. Granny Smith and confirmed their structure by GC-MS. These putative ABA biosynthetic precursors incorporate {sup 18}O to a similar degree as ABA during 48 hours under {sup 18}O{sub 2} atmospheres. The presence of significant amounts of ABA-aldehyde can explain the unique {sup 18}O labeling pattern of ABA in this tissue, where a majority of ABA molecules containing {sup 18}O is labeled in the 1{prime}-hydroxyl group and not in the side chain carboxyl group, the primary site of incorporation for stressed leaves. Exchange of the carbonyl oxygen of ABA-aldehyde with water would decrease {sup 18}O enrichment in the side chain. Results of {sup 18}O{sub 2} experiments and feeding studies using hexadeutero-ABA-aldehyde will be presented and the biosynthetic relationship of these compounds discussed.

  18. GsSKP21, a Glycine soja S-phase kinase-associated protein, mediates the regulation of plant alkaline tolerance and ABA sensitivity.

    Science.gov (United States)

    Liu, Ailin; Yu, Yang; Duan, Xiangbo; Sun, Xiaoli; Duanmu, Huizi; Zhu, Yanming

    2015-01-01

    Plant SKP1-like family proteins, components of the SCF complex E3 ligases, are involved in the regulation of plant development and stress responses. Little is known about the precise function of SKP genes in plant responses to environmental stresses. GsSKP21 was initially identified as a potential stress-responsive gene based on the transcriptome sequencing of Glycine soja. In this study, we found that GsSKP21 protein contains highly conserved SKP domains in its N terminus and an extra unidentified domain in its C terminus. The transcript abundance of GsSKP21, detected by quantitative real-time PCR, was induced under the treatment of alkali and salt stresses. Overexpression of GsSKP21 in Arabidopsis dramatically increased plant tolerance to alkali stress. Furthermore, we found that overexpression of GsSKP21 resulted in decreased ABA sensitivity during both the seed germination and early seedling growth stages. GsSKP21 mediated ABA signaling by altering the expression levels of the ABA signaling-related and ABA-induced genes. We also investigated the tissue expression specificity and subcellular localization of GsSKP21. These results suggest that GsSKP21 is important for plant tolerance to alkali stress and plays a critical regulatory role in the ABA-mediated stress response.

  19. The top 10 reasons children with autism deserve ABA.

    Science.gov (United States)

    Walsh, Mary Beth

    2011-01-01

    We who advocate for applied behavior analysis (ABA) for children with autism spectrum disorders often construct our arguments based on the scientific evidence. However, the audience that most needs to hear this argument, that is, the parents of children, especially very young children, diagnosed with autism, may not be convinced by the science alone. This essay attempts to make the case for the multiple benefits of ABA intervention through the use of humor and anecdotes couched in a "Top Ten List," and illustrating most points with stories of an engaging child with autism (my son, Ben). PMID:22532906

  20. The ARF2-ANT-COR15A gene cascade regulates ABA-signaling-mediated resistance of large seeds to drought in Arabidopsis.

    Science.gov (United States)

    Meng, Lai-Sheng; Wang, Zhi-Bo; Yao, Shun-Qiao; Liu, Aizhong

    2015-11-01

    Seedlings of large-seeded plants are considered to be able to withstand abiotic stresses efficiently. The molecular mechanisms that underlie the involved signaling crosstalk between the large-seeded trait and abiotic tolerance are, however, largely unknown. Here, we demonstrate the molecular link that integrates plant abscisic acid (ABA) responses to drought stress into the regulation of seed mass. Both loss-of-function mutants of the Auxin Response Factor 2 (ARF2 encoding a transcription factor) and lines overexpressing AINTEGUMENTA (ANT; a transcription factor) under the 35S promoter exhibited large seed and drought-tolerant phenotypes as a result of abnormal ABA-auxin crosstalk signaling pathways in Arabidopsis. The target gene COLD-REGULATED15A (COR15a) was identified as participating in the regulation of seed development with ABA signaling through a negative regulation mechanism that is mediated by ANT. The molecular and genetic evidence presented indicate that ARF2, ANT and COR15A form an ABA-mediated signaling pathway to link modulation of seed mass with drought tolerance. These observations indicate that the ARF2 transcription factor serves as a molecular link that integrates plant ABA responses to drought stress into the regulation of seed mass. PMID:26395398

  1. ABA Regulates Subcellular Redistribution of OsABI-LIKE2, a Negative Regulator in ABA Signaling, to Control Root Architecture and Drought Resistance in Oryza sativa.

    Science.gov (United States)

    Li, Chengxiang; Shen, Hongyun; Wang, Tao; Wang, Xuelu

    2015-12-01

    The phytohormone ABA is a key stress signal in plants. Although the identification of ABA receptors led to significant progress in understanding the Arabidopsis ABA signaling pathway, there are still many unsolved mysteries regarding ABA signaling in monocots, such as rice. Here, we report that a rice ortholog of AtABI1 and AtABI2, named OsABI-LIKE2 (OsABIL2), plays a negative role in rice ABA signaling. Overexpression of OsABIL2 not only led to ABA insensitivity, but also significantly altered plant developmental phenotypes, including stomatal density and root architecture, which probably caused the hypersensitivity to drought stress. OsABIL2 interacts with OsPYL1, SAPK8 and SAPK10 both in vitro and in vivo, and the phosphatase activity of OsABIL2 was repressed by ABA-bound OsPYL1. However, unlike many other solely nuclear-localized clade A type 2C protein phosphatases (PP2Cs), OsABIL2 is localized in both the nucleus and cytosol. Furthermore, OsABIL2 interacts with and co-localized with OsPYL1 mainly in the cytosol, and ABA treatment regulates the nucleus-cytosol distribution of OsABIL2, suggesting a different mechanism for the activation of ABA signaling. Taken together, this study provides significant insights into rice ABA signaling and indicates the important role of OsABIL2 in regulating root development. PMID:26491145

  2. Rice OsiSAP7 negatively regulates ABA stress signalling and imparts sensitivity to water-deficit stress in Arabidopsis.

    Science.gov (United States)

    Sharma, Gunjan; Giri, Jitender; Tyagi, Akhilesh K

    2015-08-01

    Stress associated protein (SAP) genes in plants regulate abiotic stress responses. SAP gene family consists of 18 members in rice. Although their abiotic stress responsiveness is well established, the mechanism of their action is poorly understood. OsiSAP7 was chosen to investigate the mechanism of its action based on the dual nature of its sub-cellular localization preferentially in the nucleus or sub-nuclear speckles upon transient expression in onion epidermal cells. Its expression was down-regulated in rice seedlings under abiotic stresses. OsiSAP7 was localized evenly in the nucleus under unstressed conditions and in sub-nuclear speckles on MG132 treatment. OsiSAP7 exhibits E3 ubiquitin ligase activity in vitro. Abiotic stress responses of OsiSAP7 were assessed by its overexpression in Arabidopsis under the control of a stress inducible promoter rd29A. Stress response assessment was done at seed germination and advanced stages of development. Transgenics were ABA insensitive at seed germination stage and sensitive to water-deficit stress at advanced stage as compared to wild type (WT). They were also impaired in ABA and stress-responsive gene expression. Our study suggests that OsiSAP7 acts as a negative regulator of ABA and water-deficit stress signalling by acting as an E3 ubiquitin ligase. PMID:26089154

  3. ABA and Diverse Cultural and Linguistic Environments: A Welsh Perspective

    Science.gov (United States)

    Jones, E. W.; Hoerger, M.; Hughes, J. C.; Williams, B. M.; Jones, B.; Moseley, Y.; Hughes, D. R.; Prys, D.

    2011-01-01

    Gwynedd Local Education Authority (LEA) in North West Wales, UK, is funding a small-scale autism-specific specialist education service using ABA methodology. The program is available through the medium of Welsh, English or bilingually, depending on the individual needs of the child (Jones and Hoerger in Eur J Behav Anal 10:249-253, "2009").…

  4. Personality Traits Associated with Occupational "Burnout" in ABA Therapists

    Science.gov (United States)

    Hurt, Amy A.; Grist, Cathy Lann; Malesky, Lann A., Jr.; McCord, David M.

    2013-01-01

    Background: Applied behaviour analysis (ABA) therapists typically work one-to-one with children with autism for extended periods of time, which often leads to high levels of job-related stress, lower levels of job satisfaction, increased frequency of occupational "burnout" and higher than average job turnover (Journal of Autism…

  5. ABA Brink: Pioneer of engineering geology in South Africa

    Directory of Open Access Journals (Sweden)

    J. Haarhoff

    2007-09-01

    Full Text Available Anthony Berrange Antill Brink – beter bekend as ABA Brink aan die lesers van sy boeke, of net Tony vir sy groot aantal kennisse en vriende – was met sy geboorte in 1927 die derde en laaste kind van Rex Brink en Georgina Antill

  6. Adaptive Behaviour Assessment System: Indigenous Australian Adaptation Model (ABAS: IAAM)

    Science.gov (United States)

    du Plessis, Santie

    2015-01-01

    The study objectives were to develop, trial and evaluate a cross-cultural adaptation of the Adaptive Behavior Assessment System-Second Edition Teacher Form (ABAS-II TF) ages 5-21 for use with Indigenous Australian students ages 5-14. This study introduced a multiphase mixed-method design with semi-structured and informal interviews, school…

  7. Structural basis for basal activity and autoactivation of abscisic acid (ABA) signaling SnRK2 kinases

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Ley-Moy; Soon, Fen-Fen; Zhou, X. Edward; West, Graham M.; Kovach, Amanda; Suino-Powell, Kelly M.; Chalmers, Michael J.; Li, Jun; Yong, Eu-Leong; Zhu, Jian-Kang; Griffin, Patrick R.; Melcher, Karsten; Xu, H. Eric (Van Andel); (Scripps); (Purdue); (NU Singapore)

    2014-10-02

    Abscisic acid (ABA) is an essential hormone that controls plant growth, development, and responses to abiotic stresses. Central for ABA signaling is the ABA-mediated autoactivation of three monomeric Snf1-related kinases (SnRK2.2, -2.3, and -2.6). In the absence of ABA, SnRK2s are kept in an inactive state by forming physical complexes with type 2C protein phosphatases (PP2Cs). Upon relief of this inhibition, SnRK2 kinases can autoactivate through unknown mechanisms. Here, we report the crystal structures of full-length Arabidopsis thaliana SnRK2.3 and SnRK2.6 at 1.9- and 2.3-{angstrom} resolution, respectively. The structures, in combination with biochemical studies, reveal a two-step mechanism of intramolecular kinase activation that resembles the intermolecular activation of cyclin-dependent kinases. First, release of inhibition by PP2C allows the SnRK2s to become partially active because of an intramolecular stabilization of the catalytic domain by a conserved helix in the kinase regulatory domain. This stabilization enables SnRK2s to gain full activity by activation loop autophosphorylation. Autophosphorylation is more efficient in SnRK2.6, which has higher stability than SnRK2.3 and has well-structured activation loop phosphate acceptor sites that are positioned next to the catalytic site. Together, these data provide a structural framework that links ABA-mediated release of PP2C inhibition to activation of SnRK2 kinases.

  8. ABA and Instruction of Students with Autism Spectrum Disorders: Introduction to the Special Series.

    Science.gov (United States)

    Heflin, L. Juane; Alberto, Paul A.

    2001-01-01

    This introductory article to this special issue on the use of applied behavior analysis (ABA) with autism spectrum disorders (ASD) notes the 40-year history of ABA strategy development, verification, and generalization. It briefly introduces the following articles, which are intended to illustrate the range of ABA applications and the depth of…

  9. ABA and Students with Autism Spectrum Disorders: Issues and Considerations for Effective Practice.

    Science.gov (United States)

    Simpson, Richard L.

    2001-01-01

    This article discusses issues related to the use of applied behavior analysis (ABA) with students who have autism-related disabilities. These include: implementation forms, outcome expectations, exclusive versus selective use of ABA, time-related considerations, and personnel requirements for effective ABA implementation, evaluation, and…

  10. Coping as a Predictor of Burnout and General Health in Therapists Working in ABA Schools

    Science.gov (United States)

    Griffith, G. M.; Barbakou, A.; Hastings, R. P.

    2014-01-01

    Background: Little is known about the work-related well-being of applied behaviour analysis (ABA) therapists who work in school-based contexts and deliver ABA interventions to children with autism. Methods: A questionnaire on work-related stress (burnout), general distress, perceived supervisor support and coping was completed by 45 ABA therapists…

  11. Changes of RWC, Wilting Degree and ABA in Different Ramie Varieties under Drought Stress

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Changes of RWC, wilting degree and ABA in different ramie varieties under drought stress were studied. The results showed: (1) wilting degree and ABA increased but RWC decreased with the increase of drought sress,and (2) drought resistant varieties had higher RWC and ABA but lower wilting degree than drought sensitive varieties.

  12. Characterization of three Arabidopsis AP2/EREBP family transcription factors involved in ABA sensitivity,freeze and salt tolerance

    Institute of Scientific and Technical Information of China (English)

    MEI WenQian; LEI Juan; Xu Yu; WEI Gang; ZHU YuXian

    2007-01-01

    AP2/EREBP transcription factors (TFs) play very important roles in plant development,hormonal regulation and stress response. Upon genome-wide cDNA cloning,phylogenetic and expression pattern analyses of this plant specific TF family,we found that three of the members including At1g71450,At1g50680 and At5g13910,were likely involved in responses to ABA,cold and salt. Complementary DNAs containing putative full-length ORFs of these three TFs were obtained and fused individually to the GAL4 DNA-binding domains. All the 3 genes functioned effectively as trans-activators using yeast one-hybrid assays. RT-PCR experiments showed that the At1g71450 gene was induced by ABA and low temperature; the At1g50680 gene was responsive to quite a few stress conditions,but especially to freezing temperature; and the At5g13910 gene was induced by high salt treatment,drought and ethylene. By searching the ABRC T-DNA insertion mutant stocks,we obtained knockout lines for these TFs. Homozygous ko1 (At1g71450) plants showed a hypersensitive response to ABA during seed germination and also in stomata movement. Homozygous ko2 (At1g50680) plants showed a significant reduction in plant freezing tolerance compared to the wild type after chilling treatment. Homozygous ko3 (At5g13910) were less tolerant to high salinity than wild type plants. Our data suggest that At1g71450 is a negative regulator in ABA signaling,while At1g50680 and At5g13910 are positive regulators in cold and salt stress responses,respectively.

  13. Arabidopsis ABA Receptor RCAR1/PYL9 Interacts with an R2R3-Type MYB Transcription Factor, AtMYB44

    Directory of Open Access Journals (Sweden)

    Dekuan Li

    2014-05-01

    Full Text Available Abscisic acid (ABA signaling plays important roles in plant growth, development and adaptation to various stresses. RCAR1/PYL9 has been known as a cytoplasm and nuclear ABA receptor in Arabidopsis. To obtain further insight into the regulatory mechanism of RCAR1/PYL9, a yeast two-hybrid approach was performed to screen for RCAR1/PYL9-interacting proteins and an R2R3-type MYB transcription factor, AtMYB44, was identified. The interaction between RCAR1/PYL9 and AtMYB44 was further confirmed by glutathione S-transferase (GST pull-down and bimolecular fluorescence complementation (BiFC assays. Gene expression analysis showed that AtMYB44 negatively regulated the expression of ABA-responsive gene RAB18, in contrast to the opposite role reported for RCAR1/PYL9. Competitive GST pull-down assay and analysis of phosphatase activity demonstrated that AtMYB44 and ABI1 competed for binding to RCAR1/PYL9 and thereby reduced the inhibitory effect of RCAR1/PYL9 on ABI1 phosphatase activity in the presence of ABA in vitro. Furthermore, transient activation assay in protoplasts revealed AtMYB44 probably also decreased RCAR1/PYL9-mediated inhibition of ABI1 activity in vivo. Taken together, our work provides a reasonable molecular mechanism of AtMYB44 in ABA signaling.

  14. The aba mutant of Arabidopsis thaliana is impaired in epoxy-carotenoid biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Rock, C.D.; Zeevaart, J.A.D. (Michigan State Univ., East Lansing (United States))

    1991-09-01

    The three mutant alleles of the ABA locus of Arabidopsis thaliana result in plants that are deficient in the plant growth regulator abscisic acid (ABA). The authors have used {sup 18}O{sub 2} to label ABA in water-stressed leaves of mutant and wild-type Arabidopsis. Analysis by selected ion monitoring and tandem mass spectrometry of ({sup 18}O)ABA and its catabolites, phaseic acid and ABA-glucose ester ({beta}-D-glucopyranosyl abscisate), indicates that the aba genotypes are impaired in ABA biosynthesis and have a small ABA precursor pool of compounds that contain oxygens on the rings, presumably oxygenated carotenoids (xanthophylls). Quantitation of the carotenoids form mutant and wild-type leaves establishes that the aba alleles cause a deficiency of the epoxy-carotenoids violaxanthin and neoxanthin and an accumulation of their biosynthetic precursor, zeaxanthin. These results provide evidence that ABA is synthesized by oxidative cleavage of epoxy-carotenoids (the indirect pathway). Furthermore the carotenoid mutant they describe undergoes normal greening. Thus the aba alleles provide an opportunity to study the physiological roles of epoxy-carotenoids in photosynthesis in a higher plants.

  15. CmWRKY1 Enhances the Dehydration Tolerance of Chrysanthemum through the Regulation of ABA-Associated Genes.

    Directory of Open Access Journals (Sweden)

    Qingqing Fan

    Full Text Available WRKY transcription factors serve as antagonistic or synergistic regulators in a variety of abiotic stress responses in plants. Here, we show that CmWRKY1, a member of the group IIb WRKY family isolated from Chrysanthemum morifolium, exhibits no transcriptional activation in yeast cells. The subcellular localization examination showed that CmWRKY1 localizes to the nucleus in vivo. Furthermore, CmWRKY1-overexpressing transgenic lines exhibit enhanced dehydration tolerance in response to polyethylene glycol (PEG treatment compared with wild-type plants. We further confirmed that the transgenic plants exhibit suppressed expression levels of genes negatively regulated by ABA, such as PP2C, ABI1 and ABI2, and activated expression levels of genes positively regulated by ABA, such as PYL2, SnRK2.2, ABF4, MYB2, RAB18, and DREB1A. Taken together, our results indicate that CmWRKY1 plays an important role in the response to drought in chrysanthemum through an ABA-mediated pathway.

  16. An ABA-mimicking ligand that reduces water loss and promotes drought resistance in plants

    Institute of Scientific and Technical Information of China (English)

    Minjie Cao; Xue Liu; Yan Zhang; Xiaoqian Xue; X Edward Zhou; Karsten Melcher; Pan Gao

    2013-01-01

    Abscisic acid (ABA) is the most important hormone for plants to resist drought and other abiotic stresses.ABA binds directly to the PYR/PYL family of ABA receptors,resulting in inhibition of type 2C phosphatases (PP2C) and activation of downstream ABA signaling.It is envisioned that intervention of ABA signaling by small molecules could help plants to overcome abiotic stresses such as drought,cold and soil salinity.However,chemical instability and rapid catabolism by plant enzymes limit the practical application ofABA itseif.Here we report the identification of a small molecule ABA mimic (AM1) that acts as a potent activator of multiple members of the family of ABA receptors.In Arabidopsis,AM1 activates a gene network that is highly similar to that induced by ABA.Treatments with AM1 inhibit seed germination,prevent leaf water loss,and promote drought resistance.We solved the crystal structure of AM1 in complex with the PYL2 ABA receptor and the HAB1 PP2C,which revealed that AM1 mediates a gate-latchlock interacting network,a structural feature that is conserved in the ABA-bound receptor/PP2C complex.Together,these results demonstrate that a single small molecule ABA mimic can activate multiple ABA receptors and protect plants from water loss and drought stress.Moreover,the AM1 complex crystal structure provides a structural basis for designing the next generation of ABA-mimicking small molecules.

  17. Diversity and Evolution of AbaR Genomic Resistance Islands in Acinetobacter baumannii Strains of European Clone I▿†

    Science.gov (United States)

    Krizova, Lenka; Dijkshoorn, Lenie; Nemec, Alexandr

    2011-01-01

    To assess the diversity of AbaR genomic resistance islands in Acinetobacter baumannii European clone I (MLST clonal complex 1), we investigated 26 multidrug-resistant strains of this major clone isolated from hospitals in 21 cities of 10 European countries between 1984 and 2005. Each strain harbored an AbaR structure integrated at the same position in the chromosomal ATPase gene. AbaR3, including four subtypes based on variations in class 1 integron cassettes, and AbaR10 were found in 15 and 2 strains, respectively, whereas a new, unique AbaR variant was discovered in each of the other 9 strains. These new variants, designated AbaR11 to AbaR19 (19.8 kb to 57.5 kb), seem to be truncated derivatives of AbaR3, likely resulting from the deletions of its internal parts mediated by either IS26 elements (AbaR12 to AbaR19) or homologous recombination (AbaR11). AbaR3 was detected in all 10 strains isolated in 1984 to 1991, while AbaR11 to AbaR19 were carried only by strains isolated since 1997. Our results and those from previous publications suggest that AbaR3 is the original form of AbaR in European clone I, which may have provided strains of the lineage with a selective advantage facilitating their spread in European hospitals in the 1980s or before. PMID:21537009

  18. Rheology and Relaxation Timescales of ABA Triblock Polymer Gels

    Science.gov (United States)

    Peters, Andrew; Lodge, Timothy

    When dissolved in a midblock selective solvent, ABA polymers form gels composed of aggregated end block micelles bridged by the midblocks. While much effort has been devoted to the study of the structure of these systems, the dynamics of these systems has received less attention. We examine the underlying mechanism of shear relaxation of ABA triblock polymer gels, especially as a function of chain length, composition, and concentration. Recent work using time-resolved small-angle neutron scattering of polystyrene (PS)-block-poly(ethylene-alt-propylene) (PEP) in squalane has elucidated many aspects of the dynamics of diblock chain exchange. By using rheology to study bulk relaxation phenomena of the triblock equivalent, PS-PEP-PS, we apply the knowledge gained from the chain exchange studies to bridge the gap between the molecular and macroscopic relaxation phenomena in PS-PEP-PS triblock gels.

  19. ABA-Cloud: support for collaborative breath research.

    Science.gov (United States)

    Elsayed, Ibrahim; Ludescher, Thomas; King, Julian; Ager, Clemens; Trosin, Michael; Senocak, Uygar; Brezany, Peter; Feilhauer, Thomas; Amann, Anton

    2013-06-01

    This paper introduces the advanced breath analysis (ABA) platform, an innovative scientific research platform for the entire breath research domain. Within the ABA project, we are investigating novel data management concepts and semantic web technologies to document breath analysis studies for the long run as well as to enable their full automatic reproducibility. We propose several concept taxonomies (a hierarchical order of terms from a glossary of terms), which can be seen as a first step toward the definition of conceptualized terms commonly used by the international community of breath researchers. They build the basis for the development of an ontology (a concept from computer science used for communication between machines and/or humans and representation and reuse of knowledge) dedicated to breath research.

  20. The transcriptional regulatory network in the drought response and its crosstalk in abiotic stress responses including drought, cold and heat

    Directory of Open Access Journals (Sweden)

    Kazuo eNakashima

    2014-05-01

    Full Text Available Drought negatively impacts plant growth and the productivity of crops around the world. Understanding the molecular mechanisms in the drought response is important for improvement of drought tolerance using molecular techniques. In plants, abscisic acid (ABA is accumulated under osmotic stress conditions caused by drought, and has a key role in stress responses and tolerance. Comprehensive molecular analyses have shown that ABA regulates the expression of many genes under osmotic stress conditions, and the ABA-responsive element (ABRE is the major cis-element for ABA-responsive gene expression. Transcription factors (TFs are master regulators of gene expression. ABRE-binding protein (AREB and ABRE-binding factor (ABF TFs control gene expression in an ABA-dependent manner. SNF1-related protein kinases 2, group A 2C-type protein phosphatases, and ABA receptors were shown to control the ABA signaling pathway. ABA-independent signaling pathways such as dehydration-responsive element-binding protein (DREB TFs and NAC TFs are also involved in stress responses including drought, heat and cold. Recent studies have suggested that there are interactions between the major ABA signaling pathway and other signaling factors in stress responses. The important roles of these transcription factors in crosstalk among abiotic stress responses will be discussed. Control of ABA or stress signaling factor expression can improve tolerance to environmental stresses. Recent studies using crops have shown that stress-specific overexpression of TFs improves drought tolerance and grain yield compared with controls in the field.

  1. An ABA-based Intervention Package for Treating the Inappropriate Use of a Communication Device Within Autistic Populations

    Directory of Open Access Journals (Sweden)

    Virge Connery

    2013-08-01

    Full Text Available The principles of applied behaviour analysis (ABA are widely used with autistic populations in managing challenging behaviour. The following paper will review supporting literature for creating a treatment package for targeting the misuse of a communication device in brief detail by using key elements in ABA. It will examine various types of attention (or response that may reinforce the problem behaviour, as well as intervention methods, such as functional communication training and noncontingent reinforcement. In addition, the necessity of extinction for effective intervention will be considered. A review of the literature may help inform the development of a successful treatment package that could be implemented within applied settings. Additional desirable outcomes include: reduction in aberrant behaviour, accessing attention appropriately, establishing the correct use of the communication device and increase in manding levels.

  2. Feedback Regulation of ABA Signaling and Biosynthesis by a bZIP Transcription Factor Targets Drought-Resistance-Related Genes.

    Science.gov (United States)

    Zong, Wei; Tang, Ning; Yang, Jun; Peng, Lei; Ma, Siqi; Xu, Yan; Li, Guoliang; Xiong, Lizhong

    2016-08-01

    The OsbZIP23 transcription factor has been characterized for its essential role in drought resistance in rice (Oryza sativa), but the mechanism is unknown. In this study, we first investigated the transcriptional activation of OsbZIP23. A homolog of SnRK2 protein kinase (SAPK2) was found to interact with and phosphorylate OsbZIP23 for its transcriptional activation. SAPK2 also interacted with OsPP2C49, an ABI1 homolog, which deactivated the SAPK2 to inhibit the transcriptional activation activity of OsbZIP23. Next, we performed genome-wide identification of OsbZIP23 targets by immunoprecipitation sequencing and RNA sequencing analyses in the OsbZIP23-overexpression, osbzip23 mutant, and wild-type rice under normal and drought stress conditions. OsbZIP23 directly regulates a large number of reported genes that function in stress response, hormone signaling, and developmental processes. Among these targets, we found that OsbZIP23 could positively regulate OsPP2C49, and overexpression of OsPP2C49 in rice resulted in significantly decreased sensitivity of the abscisic acid (ABA) response and rapid dehydration. Moreover, OsNCED4 (9-cis-epoxycarotenoid dioxygenase4), a key gene in ABA biosynthesis, was also positively regulated by OsbZIP23. Together, our results suggest that OsbZIP23 acts as a central regulator in ABA signaling and biosynthesis, and drought resistance in rice. PMID:27325665

  3. Abscisic Acid Catabolism in Maize Kernels in Response to Water Deficit at Early Endosperm Development

    OpenAIRE

    Wang, Zhaolong; MAMBELLI, STEFANIA; SETTER, TIM L.

    2002-01-01

    To further our understanding of the greater susceptibility of apical kernels in maize inflorescences to water stress, abscisic acid (ABA) catabolism activity was evaluated in developing kernels with chirally separated (+)‐[3H]ABA. The predominant pathway of ABA catabolism was via 8′‐hydroxylase to form phaseic acid, while conjugation to glucose was minor. In response to water deficit imposed on whole plants during kernel development, ABA accumulated to higher concentrations in apical than bas...

  4. Liming can decrease legume crop yield and leaf gas exchange by enhancing root to shoot ABA signalling.

    Science.gov (United States)

    Rothwell, Shane A; Elphinstone, E David; Dodd, Ian C

    2015-04-01

    To meet future requirements for food production, sustainable intensive agricultural systems need to optimize nutrient availability to maximize yield, traditionally achieved by maintaining soil pH within an optimal range (6-6.5) by applying lime (calcium carbonate). However, a field trial that applied recommended liming rates to a sandy loam soil (increasing soil pH from 5.5 to 6.2) decreased pod yield of field bean (Vicia faba L. cv. Fuego) by ~30%. Subsequent pot trials, with liming that raised soil pH to 6.3-6.7, reduced stomatal conductance (g(s)) by 63, 26, and 59% in V. faba, bean (Phaseolus vulgaris), and pea (Pisum sativum), respectively. Furthermore, liming reduced shoot dry biomass by 16-24% in these species. Ionomic analysis of root xylem sap and leaf tissue revealed a decrease in phosphorus concentration that was correlated with decreased g(s): both reductions were partially reversed by adding superphosphate fertilizer. Further analysis of pea suggests that leaf gas exchange was reduced by a systemic increase (roots, xylem sap, and leaves) in the phytohormone abscisic acid (ABA) in response to lime-induced suboptimal plant phosphorus concentrations. Supplying synthetic ABA via the transpiration stream to detached pea leaves, at the same xylem sap concentrations induced by liming, decreased transpiration. Furthermore, the g(s) of the ABA-deficient mutant pea wilty was unresponsive to liming, apparently confirming that ABA mediates some responses to low phosphorus availability caused by liming. This research provides a detailed mechanistic understanding of the physiological processes by which lime application can limit crop yields, and questions the suitability of current liming recommendations. PMID:25740925

  5. H2O2 inhibits ABA-signaling protein phosphatase HAB1.

    Directory of Open Access Journals (Sweden)

    Madhuri Sridharamurthy

    Full Text Available Due to its ability to be rapidly generated and propagated over long distances, H2O2 is an important second messenger for biotic and abiotic stress signaling in plants. In response to low water potential and high salt concentrations sensed in the roots of plants, the stress hormone abscisic acid (ABA activates NADPH oxidase to generate H2O2, which is propagated in guard cells in leaves to induce stomatal closure and prevent water loss from transpiration. Using a reconstituted system, we demonstrate that H2O2 reversibly prevents the protein phosphatase HAB1, a key component of the core ABA-signaling pathway, from inhibiting its main target in guard cells, SnRK2.6/OST1 kinase. We have identified HAB1 C186 and C274 as H2O2-sensitive thiols and demonstrate that their oxidation inhibits both HAB1 catalytic activity and its ability to physically associate with SnRK2.6 by formation of intermolecular dimers.

  6. ABA crosstalk with ethylene and nitric oxide in seed dormancy and germination

    Directory of Open Access Journals (Sweden)

    Erwann eArc

    2013-03-01

    Full Text Available Dormancy is an adaptive trait that enables seed germination to coincide with favorable environmental conditions. It has been clearly demonstrated that dormancy is induced by abscisic acid (ABA during seed development on the mother plant. After seed dispersal, germination is preceded by a decline in ABA in imbibed seeds, which results from ABA catabolism through 8’-hydroxylation. The hormonal balance between ABA and gibberellins (GAs has been shown to act as an integrator of environmental cues to maintain dormancy or activate germination. The interplay of ABA with other endogenous signals is however less documented. In numerous species, ethylene counteracts ABA signaling pathways and induces germination. In Brassicaceae seeds, ethylene prevents the inhibitory effects of ABA on endosperm cap weakening, thereby facilitating endosperm rupture and radicle emergence. Moreover, enhanced seed dormancy in Arabidopsis ethylene-insensitive mutants results from greater ABA sensitivity. Conversely, ABA limits ethylene action by down-regulating its biosynthesis. Nitric oxide (NO has been proposed as a common actor in the ABA and ethylene crosstalk in seed. Indeed, convergent evidence indicates that NO is produced rapidly after seed imbibition and promotes germination by inducing the expression of the ABA 8’-hydroxylase gene, CYP707A2, and stimulating ethylene production. The role of NO and other nitrogen-containing compounds, such as nitrate, in seed dormancy breakage and germination stimulation has been reported in several species. This review will describe our current knowledge of ABA crosstalk with ethylene and NO, both volatile compounds that have been shown to counteract ABA action in seeds and to improve dormancy release and germination.

  7. Modulation Role of Abscisic Acid (ABA on Growth, Water Relations and Glycinebetaine Metabolism in Two Maize (Zea mays L. Cultivars under Drought Stress

    Directory of Open Access Journals (Sweden)

    Muhammad Ashraf

    2012-03-01

    Full Text Available The role of plant hormone abscisic acid (ABA in plants under drought stress (DS is crucial in modulating physiological responses that eventually lead to adaptation to an unfavorable environment; however, the role of this hormone in modulation of glycinebetaine (GB metabolism in maize particularly at the seedling stage is still poorly understood. Some hydroponic experiments were conducted to investigate the modulation role of ABA on plant growth, water relations and GB metabolism in the leaves of two maize cultivars, Zhengdan 958 (ZD958; drought tolerant, and Jundan 20 (JD20; drought sensitive, subjected to integrated root-zone drought stress (IR-DS simulated by the addition of polyethylene glycol (PEG, 12% w/v, MW 6000. The IR-DS substantially resulted in increased betaine aldehyde dehydrogenase (BADH activity and choline content which act as the key enzyme and initial substrate, respectively, in GB biosynthesis. Drought stress also induced accumulation of GB, whereas it caused reduction in leaf relative water content (RWC and dry matter (DM in both cultivars. The contents of ABA and GB increased in drought-stressed maize seedlings, but ABA accumulated prior to GB accumulation under the drought treatment. These responses were more predominant in ZD958 than those in JD20. Addition of exogenous ABA and fluridone (Flu (ABA synthesis inhibitor applied separately increased and decreased BADH activity, respectively. Abscisic acid application enhanced GB accumulation, leaf RWC and shoot DM production in both cultivars. However, of both maize cultivars, the drought sensitive maize cultivar (JD20 performed relatively better than the other maize cultivar ZD958 under both ABA and Flu application in view of all parameters appraised. It is, therefore, concluded that increase in both BADH activity and choline content possibly resulted in enhancement of GB accumulation under DS. The endogenous ABA was probably involved in the regulation of GB metabolism by

  8. 磷脂酶D在ABA调控气孔运动中的作用%Roles of phospholipase D in ABA-regulated stomatal movement

    Institute of Scientific and Technical Information of China (English)

    王俊斌; 丁博; 李欣; 吴天文; 陈小强; 谢晓东

    2016-01-01

    Guard cells form stomatal pores in the leaf epidermis, which enable plants to balance CO2 uptake for photosynthesis and water loss via transpiration. Abscisic acid (ABA) has been extensively studied because of the clear role of ABA in stomatal closing to limit water loss through transpiration. Phospholipase D (PLD) and its lipid product phosphatidic acid (PA) have been implicated in mediating ABA-regulated stomatal signal trans-duction. In this review, we focus on our current understanding of a connection between PLD and PA with G protein, protein phosphatase 2C and reactive oxygen species in regulating the ABA response in guard cells. Also, the role of PLDδ in ABA-regulated stomatal movement is summarized.%气孔由植物叶片表面一对保卫细胞包围而成,控制植物光合作用所需CO2的摄取和蒸腾作用水分的散失。脱落酸(abscisic acid, ABA)通过诱导气孔关闭减少植物水分散失。研究表明,磷脂酶D (phospholipase D, PLD)及其产物磷脂酸(phosphatidic acid, PA)参与ABA调节的气孔运动信号转导过程。本文主要综述在保卫细胞ABA信号途径中, PLDα1/PA与G蛋白、蛋白磷酸酶2C、活性氧等信号组分的相互作用,以及PLDδ在气孔运动中的作用。

  9. Variation in Dehydration Tolerance, ABA Sensitivity and Related Gene Expression Patterns in D-Genome Progenitor and Synthetic Hexaploid Wheat Lines

    Directory of Open Access Journals (Sweden)

    Yumeto Kurahashi

    2009-06-01

    Full Text Available The wild wheat Aegilops tauschii Coss. has extensive natural variation available for breeding of common wheat. Drought stress tolerance is closely related to abscisic acid (ABA sensitivity. In this study, 17 synthetic hexaploid wheat lines, produced by crossing the tetraploid wheat cultivar Langdon with 17 accessions of Ae. tauschii, were used for comparative analysis of natural variation in drought tolerance and ABA sensitivity. Ae. tauschii showed wide natural variation, with weak association between the traits. Drought-sensitive accessions of Ae. tauschii exhibited significantly less ABA sensitivity. D-genome variations observed at the diploid genome level were not necessarily reflected in synthetic wheats. However, synthetic wheats derived from the parental Ae. tauschii accessions with high drought tolerance were significantly more tolerant to drought stress than those from drought-sensitive accessions. Moreover, synthetic wheats with high drought tolerance showed significantly higher ABA sensitivity than drought-sensitive synthetic lines. In the hexaploid genetic background, therefore, weak association of ABA sensitivity with drought tolerance wasobserved. To study differences in gene expression patterns between stress-tolerant and -sensitive lines, levels of two Cor/Lea and three transcription factor gene transcripts were compared. The more tolerant accession of Ae. tauschii tended to accumulate more abundant transcripts of the examined genes than the sensitive accession under stress conditions. The expression patterns in the synthetic wheats seemed to be additive for parental lines exposed to drought and ABA treatments. However, the transcript levels of transcription factor genes in the synthetic wheats did not necessarily correspond to the postulated levels based on expression in parental lines. Allopolyploidization altered the expression levels of the stress-responsive genes in synthetic wheats.

  10. Uniaxial Extensional Behavior of A--B--A Thermoplastic Elastomers: Structure-Properties Relationship and Modeling

    Science.gov (United States)

    Martinetti, Luca

    At service temperatures, A--B--A thermoplastic elastomers (TPEs) behave similarly to filled (and often entangled) B-rich rubbers since B block ends are anchored on rigid A domains. Therefore, their viscoelastic behavior is largely dictated by chain mobility of the B block rather than by microstructural order. Relating the small- and large-strain response of undiluted A--B--A triblocks to molecular parameters is a prerequisite for designing associated TPE-based systems that can meet the desired linear and nonlinear rheological criteria. This dissertation was aimed at connecting the chemical and topological structure of A--B--A TPEs with their viscoelastic properties, both in the linear and in the nonlinear regime. Since extensional deformations are relevant for the processing and often the end-use applications of thermoplastic elastomers, the behavior was investigated predominantly in uniaxial extension. The unperturbed size of polymer coils is one of the most fundamental properties in polymer physics, affecting both the thermodynamics of macromolecules and their viscoelastic properties. Literature results on poly(D,L-lactide) (PLA) unperturbed chain dimensions, plateau modulus, and critical molar mass for entanglement effect in viscosity were reviewed and discussed in the framework of the coil packing model. Self-consistency between experimental estimates of melt chain dimensions and viscoelastic properties was discussed, and the scaling behaviors predicted by the coil packing model were identified. Contrary to the widespread belief that amorphous polylactide must be intrinsically stiff, the coil packing model and accurate experimental measurements undoubtedly support the flexible nature of PLA. The apparent brittleness of PLA in mechanical testing was attributed to a potentially severe physical aging occurring at room temperature and to the limited extensibility of the PLA tube statistical segment. The linear viscoelastic response of A--B--A TPEs was first

  11. Molecular Mimicry Regulates ABA Signaling by SnRK2 Kinases and PP2C Phosphatases

    Energy Technology Data Exchange (ETDEWEB)

    Soon, Fen-Fen; Ng, Ley-Moy; Zhou, X. Edward; West, Graham M.; Kovach, Amanda; Tan, M.H. Eileen; Suino-Powell, Kelly M.; He, Yuanzheng; Xu, Yong; Chalmers, Michael J.; Brunzelle, Joseph S.; Zhang, Huiming; Yang, Huaiyu; Jiang, Hualiang; Li, Jun; Yong, Eu-Leong; Cutler, Sean; Zhu, Jian-Kang; Griffin, Patrick R.; Melcher, Karsten; Xu, H. Eric (Van Andel); (Scripps); (NWU); (Purdue); (UCR); (Chinese Aca. Sci.); (NU Singapore)

    2014-10-02

    Abscisic acid (ABA) is an essential hormone for plants to survive environmental stresses. At the center of the ABA signaling network is a subfamily of type 2C protein phosphatases (PP2Cs), which form exclusive interactions with ABA receptors and subfamily 2 Snfl-related kinase (SnRK2s). Here, we report a SnRK2-PP2C complex structure, which reveals marked similarity in PP2C recognition by SnRK2 and ABA receptors. In the complex, the kinase activation loop docks into the active site of PP2C, while the conserved ABA-sensing tryptophan of PP2C inserts into the kinase catalytic cleft, thus mimicking receptor-PP2C interactions. These structural results provide a simple mechanism that directly couples ABA binding to SnRK2 kinase activation and highlight a new paradigm of kinase-phosphatase regulation through mutual packing of their catalytic sites.

  12. Comprehensive Analysis of ABA Effects on Ethylene Biosynthesis and Signaling during Tomato Fruit Ripening

    OpenAIRE

    Mou, Wangshu; Li, Dongdong; Bu, Jianwen; Jiang, Yuanyuan; Khan, Zia Ullah; Luo, Zisheng; Mao, Linchun; Ying, Tiejin

    2016-01-01

    ABA has been widely acknowledged to regulate ethylene biosynthesis and signaling during fruit ripening, but the molecular mechanism underlying the interaction between these two hormones are largely unexplored. In the present study, exogenous ABA treatment obviously promoted fruit ripening as well as ethylene emission, whereas NDGA (Nordihydroguaiaretic acid, an inhibitor of ABA biosynthesis) application showed the opposite biological effects. Combined RNA-seq with time-course RT-PCR analysis,...

  13. Involvement of plant endogenous ABA in Bacillus megaterium PGPR activity in tomato plants

    OpenAIRE

    Porcel, Rosa; Zamarreño, Ángel M.; García-Mina, José M.; AROCA, RICARDO

    2014-01-01

    Abstract Background Plant growth-promoting rhizobacteria (PGPR) are naturally occurring soil bacteria which benefit plants by improving plant productivity and immunity. The mechanisms involved in these processes include the regulation of plant hormone levels such as ethylene and abscisic acid (ABA). The aim of the present study was to determine whether the activity of Bacillus megaterium PGPR is affected by the endogenous ABA content of the host plant. The ABA-deficient tomato mutants flacca ...

  14. ABA与植物耐盐信号转导途径的研究进展%Advances of the ABA and the Salt Stress Tolerance Mechanisms in Plant Signal Transduction Pathways

    Institute of Scientific and Technical Information of China (English)

    毕影东; 刘清醒; 郭长虹; 郭东林

    2013-01-01

    盐胁迫是常见的非生物胁迫因素之一并严重地影响着植物的生长发育.简述了植物在应对盐胁迫时,在胁迫信号的感知、信号的转导和传递、胁迫诱导基因的表达等方面所形成的一系列适应性的分子机制,回顾了近年来对脱落酸信号转导和其受体的研究.分析表明脱落酸受体PYR/PYL/RCAR (pyrabatin resistance/like-pyrabatin resistance/regularly component of ABA receptors)的发现使得ABA的信号转导通路更为清楚,使ABA与植物耐盐胁迫的关系更加明确,认为ABA在植物耐盐信号转导途径中发挥了重要的作用,与经济作物的耐盐性密切相关.%High salinity is the most common abiotic stress factor in environment which impacts on the plant growth. This paper reviewed a series of molecular mechanisms of plant response to salt stress. The mechanism included signal perception, signal transduction, transmission and stress-induced gene expression and the studies on ABA signal transduction and ABA receptors in recent years. The analysis showed that the discovery of the ABA PYR/PYL/RCAR (pyrabatin resistance/ like-pyrabatin resistance/regularly component of ABA receptors) made the ABA signal transduction pathway more clearly, the relationship between ABA and salt stress was defined. ABA had play an important role in salt tolerance of plant signal transduction pathways, and closely related to the salt tolerance of economic crops.

  15. SlNCED1 and SlCYP707A2: key genes involved in ABA metabolism during tomato fruit ripening.

    Science.gov (United States)

    Ji, Kai; Kai, Wenbin; Zhao, Bo; Sun, Yufei; Yuan, Bing; Dai, Shengjie; Li, Qian; Chen, Pei; Wang, Ya; Pei, Yuelin; Wang, Hongqing; Guo, Yangdong; Leng, Ping

    2014-10-01

    Abscisic acid (ABA) plays an important role in fruit development and ripening. Here, three NCED genes encoding 9-cis-epoxycarotenoid dioxygenase (NCED, a key enzyme in the ABA biosynthetic pathway) and three CYP707A genes encoding ABA 8'-hydroxylase (a key enzyme in the oxidative catabolism of ABA) were identified in tomato fruit by tobacco rattle virus-induced gene silencing (VIGS). Quantitative real-time PCR showed that VIGS-treated tomato fruits had significant reductions in target gene transcripts. In SlNCED1-RNAi-treated fruits, ripening slowed down, and the entire fruit turned to orange instead of red as in the control. In comparison, the downregulation of SlCYP707A2 expression in SlCYP707A2-silenced fruit could promote ripening; for example, colouring was quicker than in the control. Silencing SlNCED2/3 or SlCYP707A1/3 made no significant difference to fruit ripening comparing RNAi-treated fruits with control fruits. ABA accumulation and SlNCED1transcript levels in the SlNCED1-RNAi-treated fruit were downregulated to 21% and 19% of those in control fruit, respectively, but upregulated in SlCYP707A2-RNAi-treated fruit. Silencing SlNCED1 or SlCYP707A2 by VIGS significantly altered the transcripts of a set of both ABA-responsive and ripening-related genes, including ABA-signalling genes (PYL1, PP2C1, and SnRK2.2), lycopene-synthesis genes (SlBcyc, SlPSY1 and SlPDS), and cell wall-degrading genes (SlPG1, SlEXP, and SlXET) during ripening. These data indicate that SlNCED1 and SlCYP707A2 are key genes in the regulation of ABA synthesis and catabolism, and are involved in fruit ripening as positive and negative regulators, respectively.

  16. SlNCED1 and SlCYP707A2: key genes involved in ABA metabolism during tomato fruit ripening

    Science.gov (United States)

    Ji, Kai; Kai, Wenbin; Zhao, Bo; Sun, Yufei; Yuan, Bing; Dai, Shengjie; Li, Qian; Chen, Pei; Wang, Ya; Pei, Yuelin; Wang, Hongqing; Guo, Yangdong; Leng, Ping

    2014-01-01

    Abscisic acid (ABA) plays an important role in fruit development and ripening. Here, three NCED genes encoding 9-cis-epoxycarotenoid dioxygenase (NCED, a key enzyme in the ABA biosynthetic pathway) and three CYP707A genes encoding ABA 8′-hydroxylase (a key enzyme in the oxidative catabolism of ABA) were identified in tomato fruit by tobacco rattle virus-induced gene silencing (VIGS). Quantitative real-time PCR showed that VIGS-treated tomato fruits had significant reductions in target gene transcripts. In SlNCED1-RNAi-treated fruits, ripening slowed down, and the entire fruit turned to orange instead of red as in the control. In comparison, the downregulation of SlCYP707A2 expression in SlCYP707A2-silenced fruit could promote ripening; for example, colouring was quicker than in the control. Silencing SlNCED2/3 or SlCYP707A1/3 made no significant difference to fruit ripening comparing RNAi-treated fruits with control fruits. ABA accumulation and SlNCED1transcript levels in the SlNCED1-RNAi-treated fruit were downregulated to 21% and 19% of those in control fruit, respectively, but upregulated in SlCYP707A2-RNAi-treated fruit. Silencing SlNCED1 or SlCYP707A2 by VIGS significantly altered the transcripts of a set of both ABA-responsive and ripening-related genes, including ABA-signalling genes (PYL1, PP2C1, and SnRK2.2), lycopene-synthesis genes (SlBcyc, SlPSY1 and SlPDS), and cell wall-degrading genes (SlPG1, SlEXP, and SlXET) during ripening. These data indicate that SlNCED1 and SlCYP707A2 are key genes in the regulation of ABA synthesis and catabolism, and are involved in fruit ripening as positive and negative regulators, respectively. PMID:25039074

  17. Optical conductivity of ABA-stacked trilayer graphene

    Institute of Scientific and Technical Information of China (English)

    Zhu Guo-Bao; Zhang Peng

    2013-01-01

    The optical conductivity of a trilayer graphene is studied using the Kubo-Greenwood formula.We calculate the real part of the diagonal optical conductivity of an ABA-stacked trilayer graphene with different Fermi energies.The optical conductivity arises from interband matrix elements of the electric current operator involving the transitions from the occupied states to the unoccupied ones.We study the dependence of the real part of the diagonal optical conductivity on the photon energy,and the role of the transitions.

  18. Identification and functional expression of the pepper RING type E3 ligase, CaDTR1, involved in drought stress tolerance via ABA-mediated signalling.

    Science.gov (United States)

    Joo, Hyunhee; Lim, Chae Woo; Lee, Sung Chul

    2016-01-01

    Drought negatively affects plant growth and development, thereby leading to loss of crop productivity. Several plant E3 ubiquitin ligases act as positive or negative regulators of abscisic acid (ABA) and thus play important roles in the drought stress response. Here, we show that the C3HC4-type RING finger E3 ligase, CaDTR1, regulates the drought stress response via ABA-mediated signalling. CaDTR1 contains an amino-terminal RING finger motif and two carboxyl-terminal hydrophobic regions; the RING finger motif functions during attachment of ubiquitins to the target proteins, and the carboxyl-terminal hydrophobic regions function during subcellular localisation. The expression of CaDTR1 was induced by ABA, drought, and NaCl treatments. CaDTR1 localised in the nucleus and displayed in vitro E3 ubiquitin ligase activity. CaDTR1-silenced pepper plants exhibited a drought-sensitive phenotype characterised by high levels of transpirational water loss. On the other hand, CaDTR1-overexpressing (OX) Arabidopsis plants exhibited an ABA-hypersensitive phenotype during the germinative and post-germinative growth stages. Moreover, in contrast to CaDTR1-silenced pepper plants, CaDTR1-OX plants exhibited a drought-tolerant phenotype characterised by low levels of transpirational water loss via increased stomatal closure and high leaf temperatures. Our data indicate that CaDTR1 functions as a positive regulator of the drought stress response via ABA-mediated signalling. PMID:27439598

  19. Proteomic analysis reveals differential accumulation of small heat shock proteins and late embryogenesis abundant proteins between ABA-deficient mutant vp5 seeds and wild-type Vp5 seeds in maize

    Directory of Open Access Journals (Sweden)

    Xiaolin eWu

    2015-01-01

    Full Text Available ABA is a major plant hormone that plays important roles during many phases of plant life cycle, including seed development, maturity and dormancy, and especially the acquisition of desiccation tolerance. Understanding of the molecular basis of ABA-mediated plant response to stress is of interest not only in basic research on plant adaptation but also in applied research on plant productivity. Maize mutant viviparous-5 (vp5, deficient in ABA biosynthesis in seeds, is a useful material for studying ABA-mediated response in maize. Due to carotenoid deficiency, vp5 endosperm is white, compared to yellow Vp5 endosperm. However, the background difference at proteome level between vp5 and Vp5 seeds is unclear. This study aimed to characterize proteome alterations of maize vp5 seeds and to identify ABA-dependent proteins during seed maturation. We compared the embryo and endosperm proteomes of vp5 and Vp5 seeds by gel-based proteomics. Up to 46 protein spots, most in embryos, were found to be differentially accumulated between vp5 and Vp5. The identified proteins included small heat shock proteins (sHSPs, late embryogenesis abundant (LEA proteins, stress proteins, storage proteins and enzymes among others. However, EMB564, the most abundant LEA protein in maize embryo, accumulated in comparable levels between vp5 and Vp5 embryos, which contrasted to previously characterized, greatly lowered expression of emb564 mRNA in vp5 embryos. Moreover, LEA proteins and sHSPs displayed differential accumulations in vp5 embryos: six out of eight identified LEA proteins decreased while nine sHSPs increased in abundance. Finally, we discussed the possible causes of global proteome alterations, especially the observed differential accumulation of identified LEA proteins and sHSPs in vp5 embryos. The data derived from this study provides new insight into ABA-dependent proteins and ABA-mediated response during maize seed maturation.

  20. Proteomic analysis reveals differential accumulation of small heat shock proteins and late embryogenesis abundant proteins between ABA-deficient mutant vp5 seeds and wild-type Vp5 seeds in maize.

    Science.gov (United States)

    Wu, Xiaolin; Gong, Fangping; Yang, Le; Hu, Xiuli; Tai, Fuju; Wang, Wei

    2014-01-01

    ABA is a major plant hormone that plays important roles during many phases of plant life cycle, including seed development, maturity and dormancy, and especially the acquisition of desiccation tolerance. Understanding of the molecular basis of ABA-mediated plant response to stress is of interest not only in basic research on plant adaptation but also in applied research on plant productivity. Maize mutant viviparous-5 (vp5), deficient in ABA biosynthesis in seeds, is a useful material for studying ABA-mediated response in maize. Due to carotenoid deficiency, vp5 endosperm is white, compared to yellow Vp5 endosperm. However, the background difference at proteome level between vp5 and Vp5 seeds is unclear. This study aimed to characterize proteome alterations of maize vp5 seeds and to identify ABA-dependent proteins during seed maturation. We compared the embryo and endosperm proteomes of vp5 and Vp5 seeds by gel-based proteomics. Up to 46 protein spots, most in embryos, were found to be differentially accumulated between vp5 and Vp5. The identified proteins included small heat shock proteins (sHSPs), late embryogenesis abundant (LEA) proteins, stress proteins, storage proteins and enzymes among others. However, EMB564, the most abundant LEA protein in maize embryo, accumulated in comparable levels between vp5 and Vp5 embryos, which contrasted to previously characterized, greatly lowered expression of emb564 mRNA in vp5 embryos. Moreover, LEA proteins and sHSPs displayed differential accumulations in vp5 embryos: six out of eight identified LEA proteins decreased while nine sHSPs increased in abundance. Finally, we discussed the possible causes of global proteome alterations, especially the observed differential accumulation of identified LEA proteins and sHSPs in vp5 embryos. The data derived from this study provides new insight into ABA-dependent proteins and ABA-mediated response during maize seed maturation. PMID:25653661

  1. ABA modulates root growth through regulating auxin in Arabidopsis thaliana%脱落酸通过影响生长素合成及分布抑制拟南芥主根伸长

    Institute of Scientific and Technical Information of China (English)

    袁冰剑; 张森磊; 曹萌萌; 王志娟; 李霞

    2014-01-01

    脱落酸(ABA)在介导植物生长发育及逆境响应中发挥重要功能,但ABA抑制根伸长的机制尚不清楚。本文以拟南芥为材料,通过研究 ABA 对拟南芥根伸长的影响以及 ABA 受体突变体根发育表型的鉴定,探讨ABA抑制植物主根的机制。研究发现:ABA能够抑制主根生长及伸长,并且经典受体PYR1/PRL介导了ABA抑制根伸长的过程;ABA能够改变细胞周期蛋白CycB1;1:GUS表达模式,并影响根中生长素分布和响应。结果表明, ABA可能通过影响生长素在根部的分布和剂量,进而影响根尖分生区细胞分裂,从而抑制根伸长。%As sessile organism, plants exhibit an amazing developmental plasticity in adapting to changing growth conditions in response to environmental stimuli. As an important organ of plants, roots variously make active changes in the face of different stimuli. It is well known that ABA (abscisic acid) is an important molecule that inhibits root growth. ABA receptor PYR1/PYL mediates ABA signaling transduction by binding with PP2C proteins and activating kinases SnRK2s. However, little is known about how ABA regulates root growth and plastic development. In order to understand the mechanism underlying root growth inhibition by ABA, the effects of ABA on the size and activity of root meristem, meristematic cell cycle, and auxin amount and distribution patterns were analyzed with Arabidopsis thaliana as materials. The results showed that ABA inhibited the growth of primary roots and reduced the size of meristems of primary roots. The inhibition effect of ABA on pyr1/pyl1/pyl2 root growth reduced, which showed that ABA receptor PYR1/PYL was involved in the inhibition of root growth. Further analysis showed that ABA treatment blocked G2/M-phase transition during cell division with the accumulation of cyclin protein CYCB1;1::GUS expression. In addition, we noted that the amounts and distribution patterns of auxin in the roots

  2. A proteomic analysis of rice seed germination as affected by high temperature and ABA treatment.

    Science.gov (United States)

    Liu, Shu-Jun; Xu, Heng-Heng; Wang, Wei-Qing; Li, Ni; Wang, Wei-Ping; Møller, Ian Max; Song, Song-Quan

    2015-05-01

    Seed germination is a critical phase in the plant life cycle, but the specific events associated with seed germination are still not fully understood. In this study, we used two-dimensional gel electrophoresis followed by mass spectrometry to investigate the changes in the proteome during imbibition of Oryza sativa seeds at optimal temperature with or without abscisic acid (ABA) and high temperature (germination thermoinhibition) to further identify and quantify key proteins required for seed germination. A total of 121 protein spots showed a significant change in abundance (1.5-fold increase/decrease) during germination under all conditions. Among these proteins, we found seven proteins specifically associated with seed germination including glycosyl hydrolases family 38 protein, granule-bound starch synthase 1, Os03g0842900 (putative steroleosin-B), N-carbamoylputrescine amidase, spermidine synthase 1, tubulin α-1 chain and glutelin type-A; and a total of 20 imbibition response proteins involved in energy metabolism, cell growth, cell defense and storage proteins. High temperature inhibited seed germination by decreasing the abundance of proteins involved in methionine metabolism, amino acid biosynthesis, energy metabolism, reserve degradation, protein folding and stress responses. ABA treatment inhibited germination and decreased the abundance of proteins associated with methionine metabolism, energy production and cell division. Our results show that changes in many biological processes including energy metabolism, protein synthesis and cell defense and rescue occurred as a result of all treatments, while enzymes involved in methionine metabolism and weakening of cell wall specifically accumulated when the seeds germinated at the optimal temperature. PMID:25270993

  3. A proteomic analysis of rice seed germination as affected by high temperature and ABA treatment.

    Science.gov (United States)

    Liu, Shu-Jun; Xu, Heng-Heng; Wang, Wei-Qing; Li, Ni; Wang, Wei-Ping; Møller, Ian Max; Song, Song-Quan

    2015-05-01

    Seed germination is a critical phase in the plant life cycle, but the specific events associated with seed germination are still not fully understood. In this study, we used two-dimensional gel electrophoresis followed by mass spectrometry to investigate the changes in the proteome during imbibition of Oryza sativa seeds at optimal temperature with or without abscisic acid (ABA) and high temperature (germination thermoinhibition) to further identify and quantify key proteins required for seed germination. A total of 121 protein spots showed a significant change in abundance (1.5-fold increase/decrease) during germination under all conditions. Among these proteins, we found seven proteins specifically associated with seed germination including glycosyl hydrolases family 38 protein, granule-bound starch synthase 1, Os03g0842900 (putative steroleosin-B), N-carbamoylputrescine amidase, spermidine synthase 1, tubulin α-1 chain and glutelin type-A; and a total of 20 imbibition response proteins involved in energy metabolism, cell growth, cell defense and storage proteins. High temperature inhibited seed germination by decreasing the abundance of proteins involved in methionine metabolism, amino acid biosynthesis, energy metabolism, reserve degradation, protein folding and stress responses. ABA treatment inhibited germination and decreased the abundance of proteins associated with methionine metabolism, energy production and cell division. Our results show that changes in many biological processes including energy metabolism, protein synthesis and cell defense and rescue occurred as a result of all treatments, while enzymes involved in methionine metabolism and weakening of cell wall specifically accumulated when the seeds germinated at the optimal temperature.

  4. None of the As in ABA Stand for Autism: Dispelling the Myths

    Science.gov (United States)

    Dillenburger, Karola; Keenan, Mickey

    2009-01-01

    Interventions that are based on scientific principles of applied behaviour analysis (ABA) are recognised as effective treatments for children with autism spectrum disorder (ASD) by many governments and professionals (Office of the Surgeon General, 2000; Ontario IBI Initiative, 2002). However, many still view ABA as one of many treatments for…

  5. Douglass Developmental Disabilities Center: An ABA Program for Children and Adults with Autism Spectrum Disorders

    Science.gov (United States)

    Handleman, Jan S.; Harris, Sandra L.

    2005-01-01

    There is increasing evidence that Applied Behavior Analysis (ABA) is an effective, and often superior, method to teach children with Autism Spectrum Disorders ASD), than other methods. The Douglass Developmental Disabilities Center of Rutgers University (DDDC) has been using ABA for more than thirty years to teach toddlers, young children,…

  6. Brief Report: Comparative ABA and DIR Trials in Twin Brothers with Autism

    Science.gov (United States)

    Hilton, Jane C.; Seal, Brenda C.

    2007-01-01

    Trial interventions in DIR and ABA with twin brothers with autism were offered to help the parents choose one of the programs for their sons. Pre- and post-test scores on the Communication and Symbolic Behavior Scales (CSBS) revealed a slight gain in the composite score of the ABA child and a slight loss in the score of the DIR child. Contrasted…

  7. From the Classroom to the Family Room: Using ABA for Best Behavior

    Science.gov (United States)

    Smith, Dawn

    2010-01-01

    When it comes to supporting individuals with disabilities including Autism Spectrum Disorder (ASD), Applied Behavior Analysis (ABA) can be an invaluable tool in understanding and changing behavior. More than a technique or method, ABA is a disciplined approach rooted in science to teach specific skills and then reinforce them so individuals can…

  8. Well-defined ABA- and BAB-type block copolymers of PDMAEMA and PCL

    DEFF Research Database (Denmark)

    Bruce, Carl; Javakhishvili, Irakli; Fogelstrom, Linda;

    2014-01-01

    Triblock copolymers of ABA- and BAB-type consisting of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA, A) and poly(epsilon-caprolactone) (PCL, B) have successfully been prepared. PDMAEMA-b-PCL-b-PDMAEMA (ABA) and PCL-b-PDMAEMA-b-PCL (BAB) were synthesised by a combination of ring-opening poly...

  9. Drought-Induced Changes in Xylem Sap pH,ABA and Stomatal Conductance

    Institute of Scientific and Technical Information of China (English)

    GUO Xiu-lin; LIU Zi-hui; Razzaq; LI Guang-min

    2004-01-01

    Upstream signals potentially regulating evaporation and stomatal conductance were investigated using 6-8-leaf-old maize(Zea may L.)seedlings which were grown in a greenhouse.Pressure chamber was used to measure leaf water potential and to collect xylem sap.The pH of xylem sap in stems was higher than that in root,and the abscisic acid(ABA)concentration in stems was the highest in well-watered seedlings.The ABA concentration and pH of xylem sap in roots,stems and leaves increased,and the ABA concentration in leaves reached the maximum during drought stress.The treatment of roots with exogenous ABA solution(100 μmol L-1)increased xylem sap ABA concentration in all organs measured,and induced stomatal closure,but did not change ABA distribution among organs of maize seedlings.The combined effects of external pH buffer on pH,ABA of xylem sap and stomatal behavior indicated that pH,as a root-source signal to leaves under drought stress,regulated stomatal closure through accumulating ABA in leaves or guard cells.

  10. A Silvicultura Madeireira na Secretaria de Desenvolvimento Regional de Joaçaba – SDR de Joaçaba

    Directory of Open Access Journals (Sweden)

    Augusto Fischer

    2015-01-01

    Full Text Available This work discusses the potentialities for forestry in the area covered by the Secretary of Regional Development of Joaçaba – SRD of Joaçaba, in state of Santa Catarina. To develop this study, exploratory and descriptive research with qualitative and quantitative approach, and procedures of bibliographical and documentary research were used. The study comprises 13 counties of the region object of this work. Data were extracted from the databases of the Brazilian Institute of Geography and Statistics – IBGE and supplemented with data of other public organisms and private representative organisms of the forestry sector. The studies consisted of analysis of historical production of charcoal, firewood and timber in logs for pulp and paper and for various purposes. Also there were explored documents on studies of soil characteristics to identify the soil characteristics of the region. The results indicate that in seven counties potentialities are characterized as unattractive for development of forestry for wood and biomass production, in two counties are possibilities for moderate expansion, in three counties is possible a significant increase in production, and in one county with large production it was impossible to define trends.

  11. Transcriptional Responses to Gibberellin and Abscisic Acid in Barley Aleurone

    Institute of Scientific and Technical Information of China (English)

    Kegui Chen; Yong-Qiang Charles An

    2006-01-01

    Cereal aleurone has been established as a model system to investigate giberrellin (GA) and abscisic acid (ABA) responses. Using Barley 1 GeneChip, we examined the mRNA accumulation of over 22 000 genes in de-embryonated barley aleurone treated with GA and ABA. We observed that 1328 genes had more than a threefold change in response to GA treatment, whereas 206 genes had a more than threefold change in response to ABA treatment. Interestingly, approximately 2.5-fold more genes were up-regulated than downregulated by ABA. Eighty-three genes were differentially regulated by both GA and ABA. Most of the genes were subject to antagonistic regulation by ABA and GA, particularly for genes related to seed maturation and germination, such as genes encoding late embryogenesis abundant proteins and storage mobilization enzymes. This supports the antagonistic roles of GA and ABA in seed maturation and seed germination.Interestingly, we observed that a significant percentage of the genes were coordinately regulated by both GA and ABA. Some GA-responsive genes encoded proteins involved in ethylene, jasmonate, brassinosteroid and auxin metabolic and signaling transduction pathways, suggesting their potential interaction with the GA response. We also identified a group of transcription factor genes, such as MYB and Homeobox genes, that were differentially regulated by GA. In addition, a number of GA- and/or ABA-responsive genes encoded components potentially involved in GA and ABA signal transduction pathway. Overall, the present study provides a comprehensive and global view of transcript expression accompanying the GA and ABA response in barley aleurone and identifies a group of genes with potential regulatory functions in GA- and ABA-signaling pathways for future functional validation.

  12. PP2C-like Promoter and Its Deletion Variants Are Induced by ABA but Not by MeJA and SA in Arabidopsis thaliana

    Science.gov (United States)

    Bhalothia, Purva; Sangwan, Chetna; Alok, Anshu; Mehrotra, Sandhya; Mehrotra, Rajesh

    2016-01-01

    Gene expression is mediated through interaction between cis regulatory elements and its cognate transcription factors. Cis regulatory elements are defined as non-coding DNA sequences that provide the binding sites for transcription factors and are clustered in the upstream region of genes. ACGT cis regulatory element is one of the important cis regulatory elements found to be involved in diverse biological processes like auxin response, salicylic acid (SA) response, UV light response, ABA response and jasmonic acid (JA) response. We identified through in silico analysis that the upstream region of protein phosphatase 2C (PP2C) gene has a distinct genetic architecture of ACGT elements. In the present study, the activation of the full length promoter and its deletion constructs like 900 base pair, 500 base pair, 400 base pair and NRM (Nathji Rajesh Mehrotra) were examined by stable transformation in Arabidopsis thaliana using β-glucuronidase as the reporter gene. Evaluation of deletion constructs of PP2C-like promoter was carried out in the presence of phytohormones like abscisic acid (ABA), SA and JA. Our result indicated that the full length and 900 base pair promoter-reporter constructs of PP2C-like promoter was induced in response to ABA but not to methyl jasmonate and SA. PMID:27200023

  13. Medial prefrontal cortex involvement in the expression of extinction and ABA renewal of instrumental behavior for a food reinforcer.

    Science.gov (United States)

    Eddy, Meghan C; Todd, Travis P; Bouton, Mark E; Green, John T

    2016-02-01

    Instrumental renewal, the return of extinguished instrumental responding after removal from the extinction context, is an important model of behavioral relapse that is poorly understood at the neural level. In two experiments, we examined the role of the dorsomedial prefrontal cortex (dmPFC) and the ventromedial prefrontal cortex (vmPFC) in extinction and ABA renewal of instrumental responding for a sucrose reinforcer. Previous work, exclusively using drug reinforcers, has suggested that the roles of the dmPFC and vmPFC in expression of extinction and ABA renewal may depend at least in part on the type of drug reinforcer used. The current experiments used a food reinforcer because the behavioral mechanisms underlying the extinction and renewal of instrumental responding are especially well worked out in this paradigm. After instrumental conditioning in context A and extinction in context B, we inactivated dmPFC, vmPFC, or a more ventral medial prefrontal cortex region by infusing baclofen/muscimol (B/M) just prior to testing in both contexts. In rats with inactivated dmPFC, ABA renewal was still present (i.e., responding increased when returned to context A); however responding was lower (less renewal) than controls. Inactivation of vmPFC increased responding in context B (the extinction context) and decreased responding in context A, indicating no renewal in these animals. There was no effect of B/M infusion on rats with cannula placements ventral to the vmPFC. Fluorophore-conjugated muscimol was infused in a subset of rats following test to visualize infusion spread. Imaging suggested that the infusion spread was minimal and mainly constrained to the targeted area. Together, these experiments suggest that there is a region of medial prefrontal cortex encompassing both dmPFC and vmPFC that is important for ABA renewal of extinguished instrumental responding for a food reinforcer. In addition, vmPFC, but not dmPFC, is important for expression of extinction of

  14. Intrinsic superconductivity in ABA-stacked trilayer graphene

    Directory of Open Access Journals (Sweden)

    Haiwen Liu

    2012-12-01

    Full Text Available We study the phonon-mediated superconductivity in light doped ABA-stacked trilayer graphene system by means of two theoretical models. We find superconducting transition temperature TC can be greatly enlarged by tuning the Fermi energy away from neutral point. Utilizing realistic parameters, we find Tc is approximately 1 K even under weak doping condition EF = 0.1 eV. Specifically, we give out the analytical expression for superconductivity gap △ and superconducting transition temperature Tc for negative-U Hubbard model. Further, we consider the thermal fluctuation and calculate the Berezinskii-Kosterlitz-Thouless critical temperature TBKT. Besides, we consider a two-band BCS model in comparision with the negative-U Hubbard model. The results for both models are qualitatively consistent. Our study provides a promising possibility for realizing intrinsic superconductivity in multilayer graphene systems.

  15. ABA biosynthesis defective mutants reduce some free amino acids accumulation under drought stress in tomato leaves in comparison with Arabidopsis plants tissues

    Directory of Open Access Journals (Sweden)

    Adnan Ali Al.Asbahi

    2012-05-01

    Full Text Available The ability of plants to tolerate drought conditions is crucial for plant survival and crop production worldwide. The present data confirm previous findings reported existence of a strong relation between abscisic acid (ABA content and amino acid accumulation as response water stress which is one of the most important defense mechanism activated during water stress in many plant species. Therefore, free amino acids were measured to determine any changes in the metabolite pool in relation to ABA content. The ABA defective mutants of Arabidopsis plants were subjected to leaf dehydration for Arabidopsis on Whatman 3 mm filter paper at room temperature while, tomato mutant plants were subjected to drought stresses for tomato plants by withholding water. To understand the signal transduction mechanisms underlying osmotic stress-regulating gene induction and activation of osmoprotectant free amino acid synthesizing genes, we carried out a genetic screen to isolate Arabidopsis mutants defective in ABA biosynthesis under drought stress conditions. The present results revealed an accumulation of specific free amino acid in water stressed tissues in which majority of free amino acids are increased especially those playing an osmoprotectant role such as proline and glycine. Drought stress related Amino acids contents are significantly reduced in the mutants under water stress condition while they are increased significantly in the wild types plants. The exhibited higher accumulation of other amino acids under stressed condition in the mutant plants suggest that, their expressions are regulated in an ABA independent pathways. In addition, free amino acids content changes during water stress condition suggest their contribution in drought toleration as common compatible osmolytes.

  16. Effects of modulation of calcium levels and calcium fluxes on ABA- induced gene expression in barley aleurone

    NARCIS (Netherlands)

    Meulen, R.M. van der; Visser, K.; Wang, M.

    1996-01-01

    We present data to elucidate the involvement of calcium ions in abscisic acid (ABA)-induced gene expression. Modulation of external calcium concentrations was able to affect ABA-induced specific RAB gene expression. At a constant ABA level with increasing extracellular calcium level, an increasing R

  17. Type B Heterotrimeric G Protein γ-Subunit Regulates Auxin and ABA Signaling in Tomato[OPEN

    Science.gov (United States)

    Subramaniam, Gayathery; Trusov, Yuri; Hayashi, Satomi; Batley, Jacqueline

    2016-01-01

    Heterotrimeric G proteins composed of α, β, and γ subunits are central signal transducers mediating the cellular response to multiple stimuli in most eukaryotes. Gγ subunits provide proper cellular localization and functional specificity to the heterotrimer complex. Plant Gγ subunits, divided into three structurally distinct types, are more diverse than their animal counterparts. Type B Gγ subunits, lacking a carboxyl-terminal isoprenylation motif, are found only in flowering plants. We present the functional characterization of type B Gγ subunit (SlGGB1) in tomato (Solanum lycopersicum). We show that SlGGB1 is the most abundant Gγ subunit in tomato and strongly interacts with the Gβ subunit. Importantly, the green fluorescent protein-SlGGB1 fusion protein as well as the carboxyl-terminal yellow fluorescent protein-SlGGB1/amino-terminal yellow fluorescent protein-Gβ heterodimer were localized in the plasma membrane, nucleus, and cytoplasm. RNA interference-mediated silencing of SlGGB1 resulted in smaller seeds, higher number of lateral roots, and pointy fruits. The silenced lines were hypersensitive to exogenous auxin, while levels of endogenous auxins were lower or similar to those of the wild type. SlGGB1-silenced plants also showed strong hyposensitivity to abscisic acid (ABA) during seed germination but not in other related assays. Transcriptome analysis of the transgenic seeds revealed abnormal expression of genes involved in ABA sensing, signaling, and response. We conclude that the type B Gγ subunit SlGGB1 mediates auxin and ABA signaling in tomato. PMID:26668332

  18. Arabidopsis CPR5 independently regulates seed germination and postgermination arrest of development through LOX pathway and ABA signaling.

    Directory of Open Access Journals (Sweden)

    Guilan Gao

    Full Text Available The phytohormone abscisic acid (ABA and the lipoxygenases (LOXs pathway play important roles in seed germination and seedling growth and development. Here, we reported on the functional characterization of Arabidopsis CPR5 in the ABA signaling and LOX pathways. The cpr5 mutant was hypersensitive to ABA in the seed germination, cotyledon greening and root growth, whereas transgenic plants overexpressing CPR5 were insensitive. Genetic analysis demonstrated that CPR5 gene may be located downstream of the ABI1 in the ABA signaling pathway. However, the cpr5 mutant showed an ABA independent drought-resistant phenotype. It was also found that the cpr5 mutant was hypersensitive to NDGA and NDGA treatment aggravated the ABA-induced delay in the seed germination and cotyledon greening. Taken together, these results suggest that the CPR5 plays a regulatory role in the regulation of seed germination and early seedling growth through ABA and LOX pathways independently.

  19. Ethylene responses in rice roots and coleoptiles are differentially regulated by a carotenoid isomerase-mediated abscisic acid pathway.

    Science.gov (United States)

    Yin, Cui-Cui; Ma, Biao; Collinge, Derek Phillip; Pogson, Barry James; He, Si-Jie; Xiong, Qing; Duan, Kai-Xuan; Chen, Hui; Yang, Chao; Lu, Xiang; Wang, Yi-Qin; Zhang, Wan-Ke; Chu, Cheng-Cai; Sun, Xiao-Hong; Fang, Shuang; Chu, Jin-Fang; Lu, Tie-Gang; Chen, Shou-Yi; Zhang, Jin-Song

    2015-04-01

    Ethylene and abscisic acid (ABA) act synergistically or antagonistically to regulate plant growth and development. ABA is derived from the carotenoid biosynthesis pathway. Here, we analyzed the interplay among ethylene, carotenoid biogenesis, and ABA in rice (Oryza sativa) using the rice ethylene response mutant mhz5, which displays a reduced ethylene response in roots but an enhanced ethylene response in coleoptiles. We found that MHZ5 encodes a carotenoid isomerase and that the mutation in mhz5 blocks carotenoid biosynthesis, reduces ABA accumulation, and promotes ethylene production in etiolated seedlings. ABA can largely rescue the ethylene response of the mhz5 mutant. Ethylene induces MHZ5 expression, the production of neoxanthin, an ABA biosynthesis precursor, and ABA accumulation in roots. MHZ5 overexpression results in enhanced ethylene sensitivity in roots and reduced ethylene sensitivity in coleoptiles. Mutation or overexpression of MHZ5 also alters the expression of ethylene-responsive genes. Genetic studies revealed that the MHZ5-mediated ABA pathway acts downstream of ethylene signaling to inhibit root growth. The MHZ5-mediated ABA pathway likely acts upstream but negatively regulates ethylene signaling to control coleoptile growth. Our study reveals novel interactions among ethylene, carotenogenesis, and ABA and provides insight into improvements in agronomic traits and adaptive growth through the manipulation of these pathways in rice.

  20. Change Detection of Lake Aba Samuel in Ethiopia

    Science.gov (United States)

    Kaczynski, R.; Rylko, A.

    2016-06-01

    Old topographic map published in 1975 elaborated from aerial photographs taken in 1972, Landsat TM data acquired in May 1986 and Landsat ETM+ from June 2002 have been used to assess the changes of the lake Aba Samuel in Ethiopia. First map of the lake has been done in the framework of UNDP project running in 1988-90 in the Ethiopian Mapping Authority. The second classification map has been done as M.Sc. thesis in the MUT in 2015. Supervised classification methods with the use of ground truth data have been used for elaboration of the Landsat TM data. From the year 1972 up to 1986 the area of the lake has decreased by 23%. From 1986 up to 2002 the area of the lake has decreased by 20%. Therefore, after 30 years the lake was smaller by 43%. This have had very bad influence on the lives of the local population. From other recent data in the period from 2002-2015 the lake has practically disappeared and now it is only a small part of the river Akaki. ENVI 5.2 and ERDAS IMAGINE 9.2 have been used for Radiometric Calibration, Quick Atmospheric Correction (QUAC) and supervised classification of Landsat ETM+ data. The Optimum Index Factor shows the best combination of Landsat TM and ETM+ bands for color composite as 1,4,5 in the color filters: B, G, R for the signature development. Methodology and final maps are enclosed in the paper.

  1. Environmental control of seed germination in Arabidopsis thaliana: the role of GA and ABA signaling pathways

    OpenAIRE

    Piskurewicz, Urszula Maria

    2010-01-01

    Seed germination is a drastic developmental transition taking the plant from a highly protected, desiccated and quiescent form of life (dry seed) into a more fragile, vegetative seedling. Seed germination is tightly controlled by the environment, which determines the relative levels of two phytohormones: GA (gibberellins) and ABA (abscisic acid). Consequently, GA and ABA are key regulators of Arabidopsis seed germination. GA stimulates germination and its synthesis upon seed imbibition is nec...

  2. Function of ABA in Stomatal Defense against Biotic and Drought Stresses

    OpenAIRE

    Chae Woo Lim; Woonhee Baek; Jangho Jung; Jung-Hyun Kim; Sung Chul Lee

    2015-01-01

    The plant hormone abscisic acid (ABA) regulates many key processes involved in plant development and adaptation to biotic and abiotic stresses. Under stress conditions, plants synthesize ABA in various organs and initiate defense mechanisms, such as the regulation of stomatal aperture and expression of defense-related genes conferring resistance to environmental stresses. The regulation of stomatal opening and closure is important to pathogen defense and control of transpirational water loss....

  3. LTP3 contributes to disease susceptibility in Arabidopsis by enhancing abscisic acid (ABA) biosynthesis.

    Science.gov (United States)

    Gao, Shan; Guo, Wenya; Feng, Wen; Liu, Liang; Song, Xiaorui; Chen, Jian; Hou, Wei; Zhu, Hongxia; Tang, Saijun; Hu, Jian

    2016-04-01

    Several plant lipid transfer proteins (LTPs) act positively in plant disease resistance. Here, we show that LTP3 (At5g59320), a pathogen and abscisic acid (ABA)-induced gene, negatively regulates plant immunity in Arabidopsis. The overexpression of LTP3 (LTP3-OX) led to an enhanced susceptibility to virulent bacteria and compromised resistance to avirulent bacteria. On infection of LTP3-OX plants with Pseudomonas syringae pv. tomato, genes involved in ABA biosynthesis, NCED3 and AAO3, were highly induced, whereas salicylic acid (SA)-related genes, ICS1 and PR1, were down-regulated. Accordingly, in LTP3-OX plants, we observed increased ABA levels and decreased SA levels relative to the wild-type. We also showed that the LTP3 overexpression-mediated enhanced susceptibility was partially dependent on AAO3. Interestingly, loss of function of LTP3 (ltp3-1) did not affect ABA pathways, but resulted in PR1 gene induction and elevated SA levels, suggesting that LTP3 can negatively regulate SA in an ABA-independent manner. However, a double mutant consisting of ltp3-1 and silent LTP4 (ltp3/ltp4) showed reduced susceptibility to Pseudomonas and down-regulation of ABA biosynthesis genes, suggesting that LTP3 acts in a redundant manner with its closest homologue LTP4 by modulating the ABA pathway. Taken together, our data show that LTP3 is a novel negative regulator of plant immunity which acts through the manipulation of the ABA-SA balance. PMID:26123657

  4. Microarray Analysis of Transcriptional Responses to Abscisic Acid and Salt Stress in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Yucheng Wang

    2013-05-01

    Full Text Available Abscisic acid (ABA plays a crucial role in plant responses to abiotic stress. To investigate differences in plant responses to salt and ABA stimulus, differences in gene expression in Arabidopsis in response to salt and ABA were compared using an Agilent oligo microarray. A total of 144 and 139 genes were significantly up- and downregulated, respectively, under NaCl stress, while 406 and 381 genes were significantly up- and downregulated, respectively, under ABA stress conditions. In addition, 31 genes were upregulated by both NaCl and ABA stresses, and 23 genes were downregulated by these stressors, suggesting that these genes may play similar roles in plant responses to salt and ABA stress. Gene ontology (GO analysis revealed four subgroups of genes, including genes in the GO categories “Molecular transducer activity”, “Growth”, “Biological adhesion” and “Pigmentation”, which were expressed in response to ABA stress but not NaCl stress. In addition, genes that play specific roles during salt or ABA stress were identified. Our results may help elucidate differences in the response of plants to salt and ABA stress.

  5. Rice G-protein subunits qPE9-1 and RGB1 play distinct roles in abscisic acid responses and drought adaptation.

    Science.gov (United States)

    Zhang, Dong-Ping; Zhou, Yong; Yin, Jian-Feng; Yan, Xue-Jiao; Lin, Sheng; Xu, Wei-Feng; Baluška, František; Wang, Yi-Ping; Xia, Yi-Ji; Liang, Guo-hua; Liang, Jian-Sheng

    2015-10-01

    Heterotrimeric GTP-binding protein (G-protein)-mediated abscisic acid (ABA) and drought-stress responses have been documented in numerous plant species. However, our understanding of the function of rice G-protein subunits in ABA signalling and drought tolerance is limited. In this study, the function of G-protein subunits in ABA response and drought resistance in rice plants was explored. It was found that the transcription level of qPE9-1 (rice Gγ subunit) gradually decreased with increasing ABA concentration and the lack of qPE9-1 showed an enhanced drought tolerance in rice plants. In contrast, mRNA levels of RGB1 (rice Gβ subunit) were significantly upregulated by ABA treatment and the lack of RGB1 led to reduced drought tolerance. Furthermore, the results suggested that qPE9-1 negatively regulates the ABA response by suppressing the expression of key transcription factors involved in ABA and stress responses, while RGB1 positively regulates ABA biosynthesis by upregulating NCED gene expression under both normal and drought stress conditions. Taken together, it is proposed that RGB1 is a positive regulator of the ABA response and drought adaption in rice plants, whereas qPE9-1 is modulated by RGB1 and functions as a negative regulator in the ABA-dependent drought-stress responses. PMID:26175353

  6. RETROSPECTIVE STUDY OF ANTIMICROBIAL RESIDUES AND RESISTANCE IN SWINE IN ABA ABIA STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    P. NWIYI

    2014-05-01

    Full Text Available Antimicrobials are used by livestock farmers to prevent and control infection. Antimicrobials are also included at sub-therapeutic doses in animal feed as growth promoters and to improve feed efficiency in intensive farming. The aim of this study was to evaluate the antimicrobial residues and resistance that could arise due to antimicrobial use in swine. The study was carried out between September 10th and December 10th 2013 in some selected swine farms in Ogbor Hill water side in Aba, Abia state. The study involved visiting the various farms, evaluating the records of previous treatment. Also the state zonal veterinary clinics visited and record of farms was collected for analysis. From the result obtained, in raining season in a given year, the frequency of tetracycline usage recorded 83.3%, penicillin recorded 75.0%, while sulfonamide recorded 25.0%. Tylosin and ivermox were the least and recorded 8.4% usage each. The swine treatment was done by the farmers hence there was consistent over-dosage of antimicrobials to the pigs as the manufacture’s guide was not complied with. The report from the records showed that some of the pigs were slaughtered and sold in the market at any time without recourse to drug with-draw. This result could be one of the responsible reasons for antimicrobial residues and resistance in swine and indeed livestock.

  7. Effects of baseline reinforcement rate on operant ABA and ABC renewal.

    Science.gov (United States)

    Berry, Meredith S; Sweeney, Mary M; Odum, Amy L

    2014-10-01

    Renewal is a relapse phenomenon that occurs when the contextual stimuli present during extinction change, and consequently, an extinguished response increases in rate. Two experiments assessed extinction and renewal of key-pecking in pigeons in a two-component multiple schedule wherein baseline reinforcer rates were delivered at relatively rich or lean rates. In Experiment 1, an ABA design was used in which baseline stimuli were steady key lights (Context A). Food was then removed during extinction, and simultaneously, the context was changed by flashing the key lights (Context B). Following extinction, steady key lights were reintroduced, but food remained unavailable. Key-pecking was more resistant to extinction and recovered to a greater degree in the rich relative to the lean component. In Experiment 2, we introduced novel stimuli following extinction (ABC renewal) rather than reintroducing baseline stimuli. Similar to Experiment 1, in Experiment 2 resistance to change and renewal remained greater in the component associated with higher reinforcer rates during baseline. These findings provide additional support for the context-specificity of operant extinction, and support the prediction of behavioral momentum theory that stimuli associated with higher rates of reinforcement engender greater persistence and relapse than those associated with lower rates of reinforcement. PMID:25241305

  8. Effects of baseline reinforcement rate on operant ABA and ABC renewal.

    Science.gov (United States)

    Berry, Meredith S; Sweeney, Mary M; Odum, Amy L

    2014-10-01

    Renewal is a relapse phenomenon that occurs when the contextual stimuli present during extinction change, and consequently, an extinguished response increases in rate. Two experiments assessed extinction and renewal of key-pecking in pigeons in a two-component multiple schedule wherein baseline reinforcer rates were delivered at relatively rich or lean rates. In Experiment 1, an ABA design was used in which baseline stimuli were steady key lights (Context A). Food was then removed during extinction, and simultaneously, the context was changed by flashing the key lights (Context B). Following extinction, steady key lights were reintroduced, but food remained unavailable. Key-pecking was more resistant to extinction and recovered to a greater degree in the rich relative to the lean component. In Experiment 2, we introduced novel stimuli following extinction (ABC renewal) rather than reintroducing baseline stimuli. Similar to Experiment 1, in Experiment 2 resistance to change and renewal remained greater in the component associated with higher reinforcer rates during baseline. These findings provide additional support for the context-specificity of operant extinction, and support the prediction of behavioral momentum theory that stimuli associated with higher rates of reinforcement engender greater persistence and relapse than those associated with lower rates of reinforcement.

  9. Dissection of Arabidopsis NCED9 promoter regulatory regions reveals a role for ABA synthesized in embryos in the regulation of GA-dependent seed germination.

    Science.gov (United States)

    Seo, Mitsunori; Kanno, Yuri; Frey, Anne; North, Helen M; Marion-Poll, Annie

    2016-05-01

    Nine-cis-epoxycarotenoid dioxygenase (NCED) catalyzes the key step of abscisic acid (ABA) biosynthesis. There are five genes encoding NCED in Arabidopsis, which differentially regulate ABA biosynthesis in a spatiotemporal manner in response to endogenous and environmental stimuli. Previous studies have shown that NCED9 is expressed in testa and embryos during seed development. In the present study, we have identified promoter regions required for the expression of NCED9 in testa and embryos, respectively. Electrophoretic mobility shift assays (EMSA) and yeast one-hybrid (Y1H) assays showed that several homeodomain-leucine zipper (HD-Zip) proteins, namely ATHBs, bound to the sequence required for expression of NCED9 in testa, suggesting that they redundantly regulate NCED9 expression. By expressing the NCED9 gene under the control of a deleted NCED9 promoter in an nced9 mutant expression was limited to embryos. Transformants were complemented for the paclobutrazol resistant germination phenotype of the mutant, suggesting that the ABA synthesis mediated by NCED9 in embryos plays an important role in the regulation of gibberellin (GA)-dependent seed germination. PMID:26993239

  10. Transcription factor WRKY46 modulates the development of Arabidopsis lateral roots in osmotic/salt stress conditions via regulation of ABA signaling and auxin homeostasis.

    Science.gov (United States)

    Ding, Zhong Jie; Yan, Jing Ying; Li, Chun Xiao; Li, Gui Xin; Wu, Yun Rong; Zheng, Shao Jian

    2015-10-01

    The development of lateral roots (LR) is known to be severely inhibited by salt or osmotic stress. However, the molecular mechanisms underlying LR development in osmotic/salt stress conditions are poorly understood. Here we show that the gene encoding the WRKY transcription factor WRKY46 (WRKY46) is expressed throughout lateral root primordia (LRP) during early LR development and that expression is subsequently restricted to the stele of the mature LR. In osmotic/salt stress conditions, lack of WRKY46 (in loss-of-function wrky46 mutants) significantly reduces, while overexpression of WRKY46 enhances, LR development. We also show that exogenous auxin largely restores LR development in wrky46 mutants, and that the auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) inhibits LR development in both wild-type (WT; Col-0) and in a line overexpressing WRKY46 (OV46). Subsequent analysis of abscisic acid (ABA)-related mutants indicated that WRKY46 expression is down-regulated by ABA signaling, and up-regulated by an ABA-independent signal induced by osmotic/salt stress. Next, we show that expression of the DR5:GUS auxin response reporter is reduced in roots of wrky46 mutants, and that both wrky46 mutants and OV46 display altered root levels of free indole-3-acetic acid (IAA) and IAA conjugates. Subsequent RT-qPCR and ChIP-qPCR experiments indicated that WRKY46 directly regulates the expression of ABI4 and of genes regulating auxin conjugation. Finally, analysis of wrky46 abi4 double mutant plants confirms that ABI4 acts downstream of WRKY46. In summary, our results demonstrate that WRKY46 contributes to the feedforward inhibition of osmotic/salt stress-dependent LR inhibition via regulation of ABA signaling and auxin homeostasis.

  11. Ethylene Responses in Rice Roots and Coleoptiles Are Differentially Regulated by a Carotenoid Isomerase-Mediated Abscisic Acid Pathway[OPEN

    Science.gov (United States)

    Yin, Cui-Cui; Ma, Biao; Collinge, Derek Phillip; Pogson, Barry James; He, Si-Jie; Xiong, Qing; Duan, Kai-Xuan; Chen, Hui; Yang, Chao; Lu, Xiang; Wang, Yi-Qin; Zhang, Wan-Ke; Chu, Cheng-Cai; Sun, Xiao-Hong; Fang, Shuang; Chu, Jin-Fang; Lu, Tie-Gang; Chen, Shou-Yi; Zhang, Jin-Song

    2015-01-01

    Ethylene and abscisic acid (ABA) act synergistically or antagonistically to regulate plant growth and development. ABA is derived from the carotenoid biosynthesis pathway. Here, we analyzed the interplay among ethylene, carotenoid biogenesis, and ABA in rice (Oryza sativa) using the rice ethylene response mutant mhz5, which displays a reduced ethylene response in roots but an enhanced ethylene response in coleoptiles. We found that MHZ5 encodes a carotenoid isomerase and that the mutation in mhz5 blocks carotenoid biosynthesis, reduces ABA accumulation, and promotes ethylene production in etiolated seedlings. ABA can largely rescue the ethylene response of the mhz5 mutant. Ethylene induces MHZ5 expression, the production of neoxanthin, an ABA biosynthesis precursor, and ABA accumulation in roots. MHZ5 overexpression results in enhanced ethylene sensitivity in roots and reduced ethylene sensitivity in coleoptiles. Mutation or overexpression of MHZ5 also alters the expression of ethylene-responsive genes. Genetic studies revealed that the MHZ5-mediated ABA pathway acts downstream of ethylene signaling to inhibit root growth. The MHZ5-mediated ABA pathway likely acts upstream but negatively regulates ethylene signaling to control coleoptile growth. Our study reveals novel interactions among ethylene, carotenogenesis, and ABA and provides insight into improvements in agronomic traits and adaptive growth through the manipulation of these pathways in rice. PMID:25841037

  12. Cell biological mechanism for triggering of ABA accumula-tion under water stress in Vicia faba leaves

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Water stress-induced ABA accumulation is a cellular signaling process from water stress perception to activation of genes encoding key enzymes of ABA biosynthesis, of which the water stress-signal perception by cells or triggering mechanism of the ABA accumulation is the center in the whole process of ABA related-stress signaling in plants. The cell biological mechanism for triggering of ABA accumulation under water stress was studied in leaves of Vicia faba. Mannitol at 890 mmol· kg-1 osmotic concentration induced an increase of more than 5 times in ABA concentra-tion in detached leaf tissues, but the same concentration of mannitol only induced an increase of less than 40 % in ABA concentration in protoplasts. Like in detached leaf tissues, ABA concentra-tion in isolated cells increased more than 10 times under the treatment of mannitol at 890 mmol·kg-1 concentration, suggesting that the interaction between plasmalemma and cell wall was essential to triggering of the water stress-induced ABA accumulation. Neither Ca2+-che- lating agent EGTA nor Ca2+ channel activator A23187 nor the two cytoskeleton inhibitors, colchicine and cyto-chalasin B, had any effect on water stress-induced ABA accumulation. Interestingly water stress-induced ABA accumulation was effectively inhibited by a non-plasmalemma-perme- able sulfhy-dryl-modifier PCMBS (p-chloromercuriphenyl-sulfonic acid), suggesting that plasmalemma pro-tein(s) may be involved in the triggering of water stress-induced ABA accumulation, and the protein may contain sulfhydryl group at its function domain.

  13. Arabidopsis CPR5 Independently Regulates Seed Germination and Postgermination Arrest of Development through LOX Pathway and ABA Signaling

    OpenAIRE

    Guilan Gao; Shengchun Zhang; Chengfeng Wang; Xiang Yang; Yaqin Wang; Xiaojun Su; Jinju Du; Chengwei Yang

    2011-01-01

    The phytohormone abscisic acid (ABA) and the lipoxygenases (LOXs) pathway play important roles in seed germination and seedling growth and development. Here, we reported on the functional characterization of Arabidopsis CPR5 in the ABA signaling and LOX pathways. The cpr5 mutant was hypersensitive to ABA in the seed germination, cotyledon greening and root growth, whereas transgenic plants overexpressing CPR5 were insensitive. Genetic analysis demonstrated that CPR5 gene may be located downst...

  14. ZmABA2, an interacting protein of ZmMPK5, is involved in abscisic acid biosynthesis and functions.

    Science.gov (United States)

    Ma, Fangfang; Ni, Lan; Liu, Libo; Li, Xi; Zhang, Huan; Zhang, Aying; Tan, Mingpu; Jiang, Mingyi

    2016-02-01

    In maize (Zea mays), the mitogen-activated protein kinase ZmMPK5 has been shown to be involved in abscisic acid (ABA)-induced antioxidant defence and to enhance the tolerance of plants to drought, salt stress and oxidative stress. However, the underlying molecular mechanisms are poorly understood. Here, using ZmMPK5 as bait in yeast two-hybrid screening, a protein interacting with ZmMPK5 named ZmABA2, which belongs to a member of the short-chain dehydrogenase/reductase family, was identified. Pull-down assay and bimolecular fluorescence complementation analysis and co-immunoprecipitation test confirmed that ZmMPK5 interacts with ZmABA2 in vitro and in vivo. Phosphorylation of Ser173 in ZmABA2 by ZmMPK5 was shown to increase the activity of ZmABA2 and the protein stability. Various abiotic stimuli induced the expression of ZmABA2 in leaves of maize plants. Pharmacological, biochemical and molecular biology and genetic analyses showed that both ZmMPK5 and ZmABA2 coordinately regulate the content of ABA. Overexpression of ZmABA2 in tobacco plants was found to elevate the content of ABA, regulate seed germination and root growth under drought and salt stress and enhance the tolerance of tobacco plants to drought and salt stress. These results suggest that ZmABA2 is a direct target of ZmMPK5 and is involved in ABA biosynthesis and functions. PMID:26096642

  15. Changes of Soluble Sugar Contents and Sucrose Invertase Activity and Their Relation to Fruit Hardness of Peach Fruits before and after Ripening%硬肉桃果实成熟前后可溶性糖含量和蔗糖转化酶活性的变化及其与果实硬度的关系

    Institute of Scientific and Technical Information of China (English)

    张冉冉; 段艳欣; 李培环; 董晓颖

    2015-01-01

    The fruits of crisp peach (Prunus persica) ‘Shuangjiuhong’ and ‘Kawanakajima Hakuto’ were used to study the changes in the soluble sugar and sucrose contents and sucrose invertase activity and their relation to fruit hardness during the period from 20 days before ripening to 20 days after ripening. The results showed that soluble sugar and sucrose content increased while the neutral invertase (NI) and the cell walls of acid inver-tase (CWI) activities continuously decreased. Correlation analysis showed that there was markedly positive cor-relation among the fruit ifrmness, neutral invertase and the cell walls of acid invertase activities and markedly negative correlation among the fruit ifrmness, soluble sugar and sucrose contents.%以硬肉桃新品种‘双久红’和常规品种‘川中岛白桃’果实为试材,研究了果实成熟前后20 d内两品种桃果实中可溶性糖含量、蔗糖含量及蔗糖代谢相关酶活性的变化情况,并对其与硬度的相关性做了分析。结果表明,成熟前后20 d内,两品种桃果实的可溶性糖和蔗糖含量均呈上升趋势,而蔗糖中性转化酶(NI)及细胞壁转化酶(CWI)的活性则不断下降。相关性分析结果表明,果实硬度与可溶性糖和蔗糖含量呈极显著负相关,而蔗糖中性转化酶和细胞壁转化酶的活性则呈极显著正相关。

  16. The Arabidopsis LYST INTERACTING PROTEIN 5 Acts in Regulating Abscisic Acid Signaling and Drought Response.

    Science.gov (United States)

    Xia, Zongliang; Huo, Yongjin; Wei, Yangyang; Chen, Qiansi; Xu, Ziwei; Zhang, Wei

    2016-01-01

    Multivesicular bodies (MVBs) are unique endosomes containing vesicles in the lumens and play essential roles in many eukaryotic cellular processes. The Arabidopsis LYST INTERACTING PROTEIN 5 (LIP5), a positive regulator of MVB biogenesis, has critical roles in biotic and abiotic stress responses. However, whether the abscisic acid (ABA) signaling is involved in LIP5-mediated stress response is largely unknown. Here, we report that LIP5 functions in regulating ABA signaling and drought response in Arabidopsis. Analyses of a LIP5 promoter-β-glucuronidase (GUS) construct revealed substantial GUS activity in whole seedlings. The expression of LIP5 was induced by ABA and drought, and overexpression of LIP5 led to ABA hypersensitivity, enhanced stomatal closure, reduced water loss, and, therefore, increased drought tolerance. On the contrary, LIP5 knockdown mutants showed ABA-insensitive phenotypes and reduced drought tolerance; suggesting that LIP5 acts in regulating ABA response. Further analysis using a fluorescent dye revealed that ABA and water stress induced cell endocytosis or vesicle trafficking in a largely LIP5-dependent manner. Furthermore, expression of several drought- or ABA-inducible marker genes was significantly down-regulated in the lip5 mutant seedlings. Collectively, our data suggest that LIP5 positively regulates drought tolerance through ABA-mediated cell signaling. PMID:27313589

  17. Grafting cucumber onto luffa improves drought tolerance by increasing ABA biosynthesis and sensitivity.

    Science.gov (United States)

    Liu, Shanshan; Li, Hao; Lv, Xiangzhang; Ahammed, Golam Jalal; Xia, Xiaojian; Zhou, Jie; Shi, Kai; Asami, Tadao; Yu, Jingquan; Zhou, Yanhong

    2016-01-01

    Balancing stomata-dependent CO2 assimilation and transpiration is a key challenge for increasing crop productivity and water use efficiency under drought stress for sustainable crop production worldwide. Here, we show that cucumber and luffa plants with luffa as rootstock have intrinsically increased water use efficiency, decreased transpiration rate and less affected CO2 assimilation capacity following drought stress over those with cucumber as rootstock. Drought accelerated abscisic acid (ABA) accumulation in roots, xylem sap and leaves, and induced the transcript of ABA signaling genes, leading to a decreased stomatal aperture and transpiration in the plants grafted onto luffa roots as compared to plants grafted onto cucumber roots. Furthermore, stomatal movement in the plants grafted onto luffa roots had an increased sensitivity to ABA. Inhibition of ABA biosynthesis in luffa roots decreased the drought tolerance in cucumber and luffa plants. Our study demonstrates that the roots of luffa have developed an enhanced ability to sense the changes in root-zone moisture and could eventually deliver modest level of ABA from roots to shoots that enhances water use efficiency under drought stress. Such a mechanism could be greatly exploited to benefit the agricultural production especially in arid and semi-arid areas. PMID:26832070

  18. Root ABA Accumulation Enhances Rice Seedling Drought Tolerance under Ammonium Supply: Interaction with Aquaporins

    Science.gov (United States)

    Ding, Lei; Li, Yingrui; Wang, Ying; Gao, Limin; Wang, Min; Chaumont, François; Shen, Qirong; Guo, Shiwei

    2016-01-01

    In previous studies, we demonstrated that ammonium nutrition enhances the drought tolerance of rice seedlings compared to nitrate nutrition and contributes to a higher root water uptake ability. It remains unclear why rice seedlings maintain a higher water uptake ability when supplied with ammonium under drought stress. Here, we focused on the effects of nitrogen form and drought stress on root abscisic acid (ABA) concentration and aquaporin expression using hydroponics experiments and stimulating drought stress with 10% PEG6000. Drought stress decreased the leaf photosynthetic rate and stomatal conductivity and increased the leaf temperature of plants supplied with either ammonium or nitrate, but especially under nitrate supply. After 4 h of PEG treatment, the root protoplast water permeability and the expression of root PIP and TIP genes decreased in plants supplied with ammonium or nitrate. After 24 h of PEG treatment, the root hydraulic conductivity, the protoplast water permeability, and the expression of some aquaporin genes increased in plants supplied with ammonium compared to those under non-PEG treatment. Root ABA accumulation was induced by 24 h of PEG treatment, especially in plants supplied with ammonium. The addition of exogenous ABA decreased the expression of PIP and TIP genes under non-PEG treatment but increased the expression of some of them under PEG treatment. We concluded that drought stress induced a down-regulation of aquaporin expression, which appeared earlier than did root ABA accumulation. With continued drought stress, aquaporin expression and activity increased due to root ABA accumulation in plants supplied with ammonium.

  19. Genome-wide identification and expression analysis of the CaNAC family members in chickpea during development, dehydration and ABA treatments.

    Directory of Open Access Journals (Sweden)

    Chien Van Ha

    Full Text Available The plant-specific NAC transcription factors (TFs play important roles in regulation of diverse biological processes, including development, growth, cell division and responses to environmental stimuli. In this study, we identified the members of the NAC TF family of chickpea (Cicer arietinum and assess their expression profiles during plant development and under dehydration and abscisic acid (ABA treatments in a systematic manner. Seventy-one CaNAC genes were detected from the chickpea genome, including 8 membrane-bound members of which many might be involved in dehydration responses as judged from published literature. Phylogenetic analysis of the chickpea and well-known stress-related Arabidopsis and rice NACs enabled us to predict several putative stress-related CaNACs. By exploring available transcriptome data, we provided a comprehensive expression atlas of CaNACs in various tissues at different developmental stages. With the highest interest in dehydration responses, we examined the expression of the predicted stress-related and membrane-bound CaNACs in roots and leaves of chickpea seedlings, subjected to well-watered (control, dehydration and ABA treatments, using real-time quantitative PCR (RT-qPCR. Nine-teen of the 23 CaNACs examined were found to be dehydration-responsive in chickpea roots and/or leaves in either ABA-dependent or -independent pathway. Our results have provided a solid foundation for selection of promising tissue-specific and/or dehydration-responsive CaNAC candidates for detailed in planta functional analyses, leading to development of transgenic chickpea varieties with improved productivity under drought.

  20. Abscisic Acid-mediated Epigenetic Processes in Plant Development and Stress Responses

    Institute of Scientific and Technical Information of China (English)

    Viswanathan Chinnusamy; Zhizhong Gong; Jian-Kang Zhu

    2008-01-01

    Abscisic acid (ABA) regulates diverse plant processes, growth and development under non-stress conditions and plays a pivotal role in abiotic stress tolerance. Although ABA-regulated genetic processes are well known, recent discoveries reveal that epigenetic processes are an integral part of ABA-regulated processes. Epigenetic mechanisms, namely, histone modifications and cytosine DNA methylation-induced modification of genome give rise to epigenomes, which add diversity and complexity to the genome of organisms. Histone monoubiquitination appears to regulate ABA levels in developing seeds through histone H2B monoubiquitination. ABA and H2B ubiquitination dependent chromatin remodeling regulate seed dormancy. Transcription factor networks necessary for seed maturation are repressed by histone deacetylases (HDACs)-dependent and PICKLE chromatin remodeling complexes (CRCs), whereas ABA induces the expression of these genes directly or through repression of HDACs. Abiotic stress-induced ABA regulates stomatal response and stress-responsive gene expression through HDACs and HOS15-dependent histone deacetylation, as well as through the ATP-dependent SWITCH/SUCROSE NONFERMENTING CRC. ABA also probably regulates the abiotic stress response through DNA methylation and short interfering RNA pathways. Further studies on ABA-regulated spigenome will be of immense use to understand the plant development, stress adaptation and stress memory.

  1. Guard cell photosynthesis is critical for stomatal turgor production, yet does not directly mediate CO2 - and ABA-induced stomatal closing.

    Science.gov (United States)

    Azoulay-Shemer, Tamar; Palomares, Axxell; Bagheri, Andisheh; Israelsson-Nordstrom, Maria; Engineer, Cawas B; Bargmann, Bastiaan O R; Stephan, Aaron B; Schroeder, Julian I

    2015-08-01

    Stomata mediate gas exchange between the inter-cellular spaces of leaves and the atmosphere. CO2 levels in leaves (Ci) are determined by respiration, photosynthesis, stomatal conductance and atmospheric [CO2 ]. [CO2 ] in leaves mediates stomatal movements. The role of guard cell photosynthesis in stomatal conductance responses is a matter of debate, and genetic approaches are needed. We have generated transgenic Arabidopsis plants that are chlorophyll-deficient in guard cells only, expressing a constitutively active chlorophyllase in a guard cell specific enhancer trap line. Our data show that more than 90% of guard cells were chlorophyll-deficient. Interestingly, approximately 45% of stomata had an unusual, previously not-described, morphology of thin-shaped chlorophyll-less stomata. Nevertheless, stomatal size, stomatal index, plant morphology, and whole-leaf photosynthetic parameters (PSII, qP, qN, FV '/FM' ) were comparable with wild-type plants. Time-resolved intact leaf gas-exchange analyses showed a reduction in stomatal conductance and CO2 -assimilation rates of the transgenic plants. Normalization of CO2 responses showed that stomata of transgenic plants respond to [CO2 ] shifts. Detailed stomatal aperture measurements of normal kidney-shaped stomata, which lack chlorophyll, showed stomatal closing responses to [CO2 ] elevation and abscisic acid (ABA), while thin-shaped stomata were continuously closed. Our present findings show that stomatal movement responses to [CO2 ] and ABA are functional in guard cells that lack chlorophyll. These data suggest that guard cell CO2 and ABA signal transduction are not directly modulated by guard cell photosynthesis/electron transport. Moreover, the finding that chlorophyll-less stomata cause a 'deflated' thin-shaped phenotype, suggests that photosynthesis in guard cells is critical for energization and guard cell turgor production. PMID:26096271

  2. Guard cell photosynthesis is critical for stomatal turgor production, yet does not directly mediate CO2 - and ABA-induced stomatal closing.

    Science.gov (United States)

    Azoulay-Shemer, Tamar; Palomares, Axxell; Bagheri, Andisheh; Israelsson-Nordstrom, Maria; Engineer, Cawas B; Bargmann, Bastiaan O R; Stephan, Aaron B; Schroeder, Julian I

    2015-08-01

    Stomata mediate gas exchange between the inter-cellular spaces of leaves and the atmosphere. CO2 levels in leaves (Ci) are determined by respiration, photosynthesis, stomatal conductance and atmospheric [CO2 ]. [CO2 ] in leaves mediates stomatal movements. The role of guard cell photosynthesis in stomatal conductance responses is a matter of debate, and genetic approaches are needed. We have generated transgenic Arabidopsis plants that are chlorophyll-deficient in guard cells only, expressing a constitutively active chlorophyllase in a guard cell specific enhancer trap line. Our data show that more than 90% of guard cells were chlorophyll-deficient. Interestingly, approximately 45% of stomata had an unusual, previously not-described, morphology of thin-shaped chlorophyll-less stomata. Nevertheless, stomatal size, stomatal index, plant morphology, and whole-leaf photosynthetic parameters (PSII, qP, qN, FV '/FM' ) were comparable with wild-type plants. Time-resolved intact leaf gas-exchange analyses showed a reduction in stomatal conductance and CO2 -assimilation rates of the transgenic plants. Normalization of CO2 responses showed that stomata of transgenic plants respond to [CO2 ] shifts. Detailed stomatal aperture measurements of normal kidney-shaped stomata, which lack chlorophyll, showed stomatal closing responses to [CO2 ] elevation and abscisic acid (ABA), while thin-shaped stomata were continuously closed. Our present findings show that stomatal movement responses to [CO2 ] and ABA are functional in guard cells that lack chlorophyll. These data suggest that guard cell CO2 and ABA signal transduction are not directly modulated by guard cell photosynthesis/electron transport. Moreover, the finding that chlorophyll-less stomata cause a 'deflated' thin-shaped phenotype, suggests that photosynthesis in guard cells is critical for energization and guard cell turgor production.

  3. Response of groundnut (arachis hypogaea L.) genotypes to plant growth regulators and drought stress

    International Nuclear Information System (INIS)

    The present study was carried out to investigate the physiological (relative water content) pod dry weight, pods plant/sup -1/, pod yield (kg plot/sup -1/), shelling (%), plant height and biochemical (endogenous ABA level) traits of peanut cultivar Swat Phalli-96 under drought stress. The result showed that drought stress significantly (p0.05) effect on various parameters under drought stress conditions. However, foliar application of ABA (10/sup -4/ M) partially ameliorated the adverse effects of drought stress on growth and yield components. Foliar application of ABA to plants when subsequently exposed to drought stress resulted in elevated levels of endogenous ABA. The endogenous ABA levels in shoot increased earlier in response to applied ABA than that of root. (author)

  4. Xylem sap collection and extraction methodologies to determine in vivo concentrations of ABA and its bound forms by gas chromatography-mass spectrometry (GC-MS

    Directory of Open Access Journals (Sweden)

    Netting Andrew G

    2012-03-01

    Full Text Available Abstract Background Accurate quantification of xylem sap ABA concentrations is important to underpin models of root-to-shoot ABA signalling to predict the physiological effects of soil drying. Growing tomato plants in a whole plant pressure chamber allowed sequential xylem sap collection from a detached leaf, the petiole stub of an otherwise intact plant and finally the de-topped root system of the same plant, to determine the impact of xylem sap sampling methodology on xylem ABA concentration. Since xylem sap can contain bound forms of ABA, a novel gas chromatography-mass spectrometry (GC-MS procedure was developed to chemically separate free ABA from two in planta bound ABA forms known as Adducts I and II and ABA-glucose-ester (ABA-GE. Results Xylem sap ABA concentrations were highly dependent on the sampling methodology used: the highest concentrations were detected in sap collected by applying an overpressure to detached leaves following the measurement of leaf water potential. Irrespective of xylem sap source, the wild-type cultivars Ailsa Craig and Rheinlands Ruhm had higher free ABA concentrations than a range of ABA-deficient mutants (notabilis, flacca and sitiens. However, in the mutants, concentrations of bound forms of ABA were similar to wild-type plants, and similar to free ABA concentrations. Conclusions Although xylem concentrations of these bound ABA forms and ABA-GE suggest they have a limited physiological impact on ABA homeostasis in tomato, the methods developed here will allow a more complete understanding of ABA biochemistry and root-to-shoot signalling in species known to have higher concentrations of these compounds.

  5. The Relationship Between Heat-induced Chilling Tolerance and Endogenous ABA Levels in Mangoes

    Institute of Scientific and Technical Information of China (English)

    ZHU Shi-jiang; JI Zuo-liang

    2002-01-01

    Heating "Zhihua" mangoes (Mangifera indica L. cv. Zhihua) in hot air at 38℃ for 12hours significantly reduced the development of chilling injury following storage for 12days at 2℃. Prolonging the heating up to 72hours acquired similar results. During the 12 days' storage at 2℃ following heating for 72hours, the membrane leakage of the mango peels showed little change, while it increased with time for the control fruits, and the endogenous ABA levels in the heated fruits were higher than that in the control. These results indicated that higher ABA rates were linked with stronger chilling tolerance in mangoes.

  6. Structure of 5-hydroxymethylcytosine-specific restriction enzyme, AbaSI, in complex with DNA

    Energy Technology Data Exchange (ETDEWEB)

    Horton, John R.; Borgaro, Janine G.; Griggs, Rose M.; Quimby, Aine; Guan, Shengxi; Zhang, Xing; Wilson, Geoffrey G.; Zheng, Yu; Zhu, Zhenyu; Cheng, Xiaodong (Emory-MED); (NE Biolabs)

    2014-07-03

    AbaSI, a member of the PvuRts1I-family of modification-dependent restriction endonucleases, cleaves DNA containing 5-hydroxymethylctosine (5hmC) and glucosylated 5hmC (g5hmC), but not DNA containing unmodified cytosine. AbaSI has been used as a tool for mapping the genomic locations of 5hmC, an important epigenetic modification in the DNA of higher organisms. Here we report the crystal structures of AbaSI in the presence and absence of DNA. These structures provide considerable, although incomplete, insight into how this enzyme acts. AbaSI appears to be mainly a homodimer in solution, but interacts with DNA in our structures as a homotetramer. Each AbaSI subunit comprises an N-terminal, Vsr-like, cleavage domain containing a single catalytic site, and a C-terminal, SRA-like, 5hmC-binding domain. Two N-terminal helices mediate most of the homodimer interface. Dimerization brings together the two catalytic sites required for double-strand cleavage, and separates the 5hmC binding-domains by ~ 70 Å, consistent with the known activity of AbaSI which cleaves DNA optimally between symmetrically modified cytosines ~ 22 bp apart. The eukaryotic SET and RING-associated (SRA) domains bind to DNA containing 5-methylcytosine (5mC) in the hemi-methylated CpG sequence. They make contacts in both the major and minor DNA grooves, and flip the modified cytosine out of the helix into a conserved binding pocket. In contrast, the SRA-like domain of AbaSI, which has no sequence specificity, contacts only the minor DNA groove, and in our current structures the 5hmC remains intra-helical. A conserved, binding pocket is nevertheless present in this domain, suitable for accommodating 5hmC and g5hmC. We consider it likely, therefore, that base-flipping is part of the recognition and cleavage mechanism of AbaSI, but that our structures represent an earlier, pre-flipped stage, prior to actual recognition.

  7. Supervisor Support as a Predictor of Burnout and Therapeutic Self-Efficacy in Therapists Working in ABA Schools

    Science.gov (United States)

    Gibson, Jennifer A.; Grey, Ian M.; Hastings, Richard P.

    2009-01-01

    Very little is known about factors potentially affecting the performance of therapists delivering applied behavior analysis (ABA) interventions for young children with autism. Eighty-one therapists working in ABA schools participated in a questionnaire study focused on their reports of burnout and perceived therapeutic self-efficacy in their work…

  8. Parents' Experiences of Applied Behaviour Analysis (ABA)-Based Interventions for Children Diagnosed with Autistic Spectrum Disorder

    Science.gov (United States)

    McPhilemy, Catherine; Dillenburger, Karola

    2013-01-01

    Applied behaviour analysis (ABA)-based programmes are endorsed as the gold standard for treatment of children with autistic spectrum disorder (ASD) in most of North America. This is not the case in most of Europe, where instead a non-specified "eclectic" approach is adopted. We explored the social validity of ABA-based interventions with…

  9. 40 CFR 63.1297 - Standards for slabstock flexible polyurethane foam production-HAP ABA emissions from the...

    Science.gov (United States)

    2010-07-01

    ... polyurethane foam production-HAP ABA emissions from the production line. 63.1297 Section 63.1297 Protection of... Pollutants for Flexible Polyurethane Foam Production § 63.1297 Standards for slabstock flexible polyurethane... § 63.1293(a)(1) shall control HAP ABA emissions from the slabstock polyurethane foam production line...

  10. The p450 monooxygenase BcABA1 is essential for abscisic acid biosynthesis in Botrytis cinerea

    DEFF Research Database (Denmark)

    Siewers, V.; Smedsgaard, Jørn; Tudzynski, P.

    2004-01-01

    The phytopathogenic ascomycete Botrytis cinerea is known to produce abscisic acid (ABA), which is thought to be involved in host-pathogen interaction. Biochemical analyses had previously shown that, in contrast to higher plants, the fungal ABA biosynthesis probably does not proceed via carotenoids...

  11. Role of protein farnesylation events in the ABA-mediated regulation of the Pinoresinol-Lariciresinol Reductase 1 (LuPLR1) gene expression and lignan biosynthesis in flax (Linum usitatissimum L.).

    Science.gov (United States)

    Corbin, Cyrielle; Decourtil, Cédric; Marosevic, Djurdjica; Bailly, Marlène; Lopez, Tatiana; Renouard, Sullivan; Doussot, Joël; Dutilleul, Christelle; Auguin, Daniel; Giglioli-Guivarc'h, Nathalie; Lainé, Eric; Lamblin, Frédéric; Hano, Christophe

    2013-11-01

    A Linum usitatissimum LuERA1 gene encoding a putative ortholog of the ERA1 (Enhanced Response to ABA 1) gene of Arabidopsis thaliana (encoding the beta subunit of a farnesyltransferase) was analyzed in silico and for its expression in flax. The gene and the protein sequences are highly similar to other sequences already characterized in plants and all the features of a farnesyltransferase were detected. Molecular modeling of LuERA1 protein confirmed its farnesyltransferase nature. LuERA1 is expressed in the vegetative organs and also in the outer seedcoat of the flaxseed, where it could modulate the previously observed regulation operated by ABA on lignan synthesis. This effect could be mediated by the regulation of the transcription of a key gene for lignan synthesis in flax, the LuPLR1 gene, encoding a pinoresinol lariciresinol reductase. The positive effect of manumycin A, a specific inhibitor of farnesyltransferase, on lignan biosynthesis in flax cell suspension systems supports the hypothesis of the involvement of such an enzyme in the negative regulation of ABA action. In Arabidopsis, ERA1 is able to negatively regulate the ABA effects and the mutant era1 has an enhanced sensitivity to ABA. When expressed in an Arabidopsis cell suspension (heterologous system) LuERA1 is able to reverse the effect of the era1 mutation. RNAi experiments in flax targeting the farnesyltransferase β-subunit encoded by the LuERA1 gene led to an increase LuPLR1 expression level associated with an increased content of lignan in transgenic calli. Altogether these results strongly suggest a role of the product of this LuERA1 gene in the ABA-mediated upregulation of lignan biosynthesis in flax cells through the activation of LuPLR1 promoter. This ABA signaling pathway involving ERA1 probably acts through the ABRE box found in the promoter sequence of LuPLR1, a key gene for lignan synthesis in flax, as demonstrated by LuPLR1 gene promoter-reporter experiments in flax cells using wild

  12. ABA and PBS: The Dangers in Creating Artificial Dichotomies in Behavioral Intervention

    Science.gov (United States)

    Weiss, Mary Jane; DelPizzo-Cheng, Eliza; LaRue, Robert H.; Sloman, Kimberly

    2009-01-01

    In recent years, there has been a great deal of controversy regarding the definition and independence of Positive Behavioral Supports (PBS) within the context of behavioral intervention. Specifically, behavior analysts have argued over whether PBS is subsumed within Applied Behavior Analysis (ABA) or whether it can be considered a separate…

  13. GsAPK, an ABA-activated and calcium-independent SnRK2-type kinase from G. soja, mediates the regulation of plant tolerance to salinity and ABA stress.

    Directory of Open Access Journals (Sweden)

    Liang Yang

    Full Text Available Plant Snf1 (sucrose non-fermenting-1 related protein kinase (SnRK, a subfamily of serine/threonine kinases, has been implicated as a crucial upstream regulator of ABA and osmotic signaling as in many other signaling cascades. In this paper, we have isolated a novel plant specific ABA activated calcium independent protein kinase (GsAPK from a highly salt tolerant plant, Glycine soja (50109, which is a member of the SnRK2 family. Subcellular localization studies using GFP fusion protein indicated that GsAPK is localized in the plasma membrane. We found that autophosphorylation and Myelin Basis Protein phosphorylation activity of GsAPK is only activated by ABA and the kinase activity also was observed when calcium was replaced by EGTA, suggesting its independence of calcium in enzyme activity. We also found that cold, salinity, drought, and ABA stress alter GsAPK gene transcripts and heterogonous overexpression of GsAPK in Arabidopsis alters plant tolerance to high salinity and ABA stress. In summary, we demonstrated that GsAPK is a Glycine soja ABA activated calcium independent SnRK-type kinase presumably involved in ABA mediated stress signal transduction.

  14. GsAPK, an ABA-activated and calcium-independent SnRK2-type kinase from G. soja, mediates the regulation of plant tolerance to salinity and ABA stress.

    Science.gov (United States)

    Yang, Liang; Ji, Wei; Gao, Peng; Li, Yong; Cai, Hua; Bai, Xi; Chen, Qin; Zhu, Yanming

    2012-01-01

    Plant Snf1 (sucrose non-fermenting-1) related protein kinase (SnRK), a subfamily of serine/threonine kinases, has been implicated as a crucial upstream regulator of ABA and osmotic signaling as in many other signaling cascades. In this paper, we have isolated a novel plant specific ABA activated calcium independent protein kinase (GsAPK) from a highly salt tolerant plant, Glycine soja (50109), which is a member of the SnRK2 family. Subcellular localization studies using GFP fusion protein indicated that GsAPK is localized in the plasma membrane. We found that autophosphorylation and Myelin Basis Protein phosphorylation activity of GsAPK is only activated by ABA and the kinase activity also was observed when calcium was replaced by EGTA, suggesting its independence of calcium in enzyme activity. We also found that cold, salinity, drought, and ABA stress alter GsAPK gene transcripts and heterogonous overexpression of GsAPK in Arabidopsis alters plant tolerance to high salinity and ABA stress. In summary, we demonstrated that GsAPK is a Glycine soja ABA activated calcium independent SnRK-type kinase presumably involved in ABA mediated stress signal transduction.

  15. Root ABA Accumulation Enhances Rice Seedling Drought Tolerance under Ammonium Supply: Interaction with Aquaporins.

    Science.gov (United States)

    Ding, Lei; Li, Yingrui; Wang, Ying; Gao, Limin; Wang, Min; Chaumont, François; Shen, Qirong; Guo, Shiwei

    2016-01-01

    In previous studies, we demonstrated that ammonium nutrition enhances the drought tolerance of rice seedlings compared to nitrate nutrition and contributes to a higher root water uptake ability. It remains unclear why rice seedlings maintain a higher water uptake ability when supplied with ammonium under drought stress. Here, we focused on the effects of nitrogen form and drought stress on root abscisic acid (ABA) concentration and aquaporin expression using hydroponics experiments and stimulating drought stress with 10% PEG6000. Drought stress decreased the leaf photosynthetic rate and stomatal conductivity and increased the leaf temperature of plants supplied with either ammonium or nitrate, but especially under nitrate supply. After 4 h of PEG treatment, the root protoplast water permeability and the expression of root PIP and TIP genes decreased in plants supplied with ammonium or nitrate. After 24 h of PEG treatment, the root hydraulic conductivity, the protoplast water permeability, and the expression of some aquaporin genes increased in plants supplied with ammonium compared to those under non-PEG treatment. Root ABA accumulation was induced by 24 h of PEG treatment, especially in plants supplied with ammonium. The addition of exogenous ABA decreased the expression of PIP and TIP genes under non-PEG treatment but increased the expression of some of them under PEG treatment. We concluded that drought stress induced a down-regulation of aquaporin expression, which appeared earlier than did root ABA accumulation. With continued drought stress, aquaporin expression and activity increased due to root ABA accumulation in plants supplied with ammonium. PMID:27559341

  16. Root ABA Accumulation Enhances Rice Seedling Drought Tolerance under Ammonium Supply: Interaction with Aquaporins

    Science.gov (United States)

    Ding, Lei; Li, Yingrui; Wang, Ying; Gao, Limin; Wang, Min; Chaumont, François; Shen, Qirong; Guo, Shiwei

    2016-01-01

    In previous studies, we demonstrated that ammonium nutrition enhances the drought tolerance of rice seedlings compared to nitrate nutrition and contributes to a higher root water uptake ability. It remains unclear why rice seedlings maintain a higher water uptake ability when supplied with ammonium under drought stress. Here, we focused on the effects of nitrogen form and drought stress on root abscisic acid (ABA) concentration and aquaporin expression using hydroponics experiments and stimulating drought stress with 10% PEG6000. Drought stress decreased the leaf photosynthetic rate and stomatal conductivity and increased the leaf temperature of plants supplied with either ammonium or nitrate, but especially under nitrate supply. After 4 h of PEG treatment, the root protoplast water permeability and the expression of root PIP and TIP genes decreased in plants supplied with ammonium or nitrate. After 24 h of PEG treatment, the root hydraulic conductivity, the protoplast water permeability, and the expression of some aquaporin genes increased in plants supplied with ammonium compared to those under non-PEG treatment. Root ABA accumulation was induced by 24 h of PEG treatment, especially in plants supplied with ammonium. The addition of exogenous ABA decreased the expression of PIP and TIP genes under non-PEG treatment but increased the expression of some of them under PEG treatment. We concluded that drought stress induced a down-regulation of aquaporin expression, which appeared earlier than did root ABA accumulation. With continued drought stress, aquaporin expression and activity increased due to root ABA accumulation in plants supplied with ammonium. PMID:27559341

  17. Field studies on the regulation of abscisic acid content and germinability during grain development of barley: molecular and chemical analysis of pre-harvest sprouting.

    Science.gov (United States)

    Chono, Makiko; Honda, Ichiro; Shinoda, Shoko; Kushiro, Tetsuo; Kamiya, Yuji; Nambara, Eiji; Kawakami, Naoto; Kaneko, Shigenobu; Watanabe, Yoshiaki

    2006-01-01

    To investigate whether the regulation of abscisic acid (ABA) content was related to germinability during grain development, two cDNAs for 9-cis-epoxycarotenoid dioxygenase (HvNCED1 and HvNCED2) and one cDNA for ABA 8'-hydroxylase (HvCYP707A1), which are enzymes thought to catalyse key regulatory steps in ABA biosynthesis and catabolism, respectively, were cloned from barley (Hordeum vulgare L.). Expression and ABA-quantification analysis in embryo revealed that HvNCED2 is responsible for a significant increase in ABA levels during the early to middle stages of grain development, and HvCYP707A1 is responsible for a rapid decrease in ABA level thereafter. The change in the embryonic ABA content of imbibing grains following dormancy release is likely to reflect changes in the expression patterns of HvNCEDs and HvCYP707A1. A major change between dormant and after-ripened grains occurred in HvCYP707A1; the increased expression of HvCYP707A1 in response to imbibition, followed by a rapid ABA decrease and a high germination percentage, was observed in the after-ripened grains, but not in the dormant grains. Under field conditions, HvNCED2 showed the same expression level and pattern during grain development in 2002, 2003, and 2004, indicating that HvNCED2 expression is regulated in a growth-dependent manner in the grains. By contrast, HvNCED1 and HvCYP707A1 showed a different expression pattern in each year, indicating that the expression of these genes is affected by environmental conditions during grain development. The varied expression levels of these genes during grain development and imbibition, which would have effects on the activity of ABA biosynthesis and catabolism, might be reflected, in part, in the germinability in field-grown barley.

  18. The receptor kinase IMPAIRED OOMYCETE SUSCEPTIBILITY1 attenuates abscisic acid responses in Arabidopsis.

    Science.gov (United States)

    Hok, Sophie; Allasia, Valérie; Andrio, Emilie; Naessens, Elodie; Ribes, Elsa; Panabières, Franck; Attard, Agnès; Ris, Nicolas; Clément, Mathilde; Barlet, Xavier; Marco, Yves; Grill, Erwin; Eichmann, Ruth; Weis, Corina; Hückelhoven, Ralph; Ammon, Alexandra; Ludwig-Müller, Jutta; Voll, Lars M; Keller, Harald

    2014-11-01

    In plants, membrane-bound receptor kinases are essential for developmental processes, immune responses to pathogens and the establishment of symbiosis. We previously identified the Arabidopsis (Arabidopsis thaliana) receptor kinase IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) as required for successful infection with the downy mildew pathogen Hyaloperonospora arabidopsidis. We report here that IOS1 is also required for full susceptibility of Arabidopsis to unrelated (hemi)biotrophic filamentous oomycete and fungal pathogens. Impaired susceptibility in the absence of IOS1 appeared to be independent of plant defense mechanism. Instead, we found that ios1-1 plants were hypersensitive to the plant hormone abscisic acid (ABA), displaying enhanced ABA-mediated inhibition of seed germination, root elongation, and stomatal opening. These findings suggest that IOS1 negatively regulates ABA signaling in Arabidopsis. The expression of ABA-sensitive COLD REGULATED and RESISTANCE TO DESICCATION genes was diminished in Arabidopsis during infection. This effect on ABA signaling was alleviated in the ios1-1 mutant background. Accordingly, ABA-insensitive and ABA-hypersensitive mutants were more susceptible and resistant to oomycete infection, respectively, showing that the intensity of ABA signaling affects the outcome of downy mildew disease. Taken together, our findings suggest that filamentous (hemi)biotrophs attenuate ABA signaling in Arabidopsis during the infection process and that IOS1 participates in this pathogen-mediated reprogramming of the host. PMID:25274985

  19. Transcriptomic Analysis Reveals Possible Influences of ABA on Secondary Metabolism of Pigments, Flavonoids and Antioxidants in Tomato Fruit during Ripening.

    Science.gov (United States)

    Mou, Wangshu; Li, Dongdong; Luo, Zisheng; Mao, Linchun; Ying, Tiejin

    2015-01-01

    Abscisic acid (ABA) has been proven to be involved in the regulation of climacteric fruit ripening, but a comprehensive investigation of its influence on ripening related processes is still lacking. By applying the next generation sequencing technology, we conducted a comparative analysis of the effects of exogenous ABA and NDGA (Nordihydroguaiaretic acid, an inhibitor of ABA biosynthesis) on tomato fruit ripening. The high throughput sequencing results showed that out of the 25728 genes expressed across all three samples, 10388 were identified as significantly differently expressed genes. Exogenous ABA was found to enhance the transcription of genes involved in pigments metabolism, including carotenoids biosynthesis and chlorophyll degradation, whereas NDGA treatment inhibited these processes. The results also revealed the crucial role of ABA in flavonoids synthesis and regulation of antioxidant system. Intriguingly, we also found that an inhibition of endogenous ABA significantly enhanced the transcriptional abundance of genes involved in photosynthesis. Our results highlighted the significance of ABA in regulating tomato ripening, which provided insight into the regulatory mechanism of fruit maturation and senescence process.

  20. Transcriptomic Analysis Reveals Possible Influences of ABA on Secondary Metabolism of Pigments, Flavonoids and Antioxidants in Tomato Fruit during Ripening.

    Directory of Open Access Journals (Sweden)

    Wangshu Mou

    Full Text Available Abscisic acid (ABA has been proven to be involved in the regulation of climacteric fruit ripening, but a comprehensive investigation of its influence on ripening related processes is still lacking. By applying the next generation sequencing technology, we conducted a comparative analysis of the effects of exogenous ABA and NDGA (Nordihydroguaiaretic acid, an inhibitor of ABA biosynthesis on tomato fruit ripening. The high throughput sequencing results showed that out of the 25728 genes expressed across all three samples, 10388 were identified as significantly differently expressed genes. Exogenous ABA was found to enhance the transcription of genes involved in pigments metabolism, including carotenoids biosynthesis and chlorophyll degradation, whereas NDGA treatment inhibited these processes. The results also revealed the crucial role of ABA in flavonoids synthesis and regulation of antioxidant system. Intriguingly, we also found that an inhibition of endogenous ABA significantly enhanced the transcriptional abundance of genes involved in photosynthesis. Our results highlighted the significance of ABA in regulating tomato ripening, which provided insight into the regulatory mechanism of fruit maturation and senescence process.

  1. ABA suppresses Botrytis cinerea elicited NO production in tomato to influence H2O2 generation and increase host susceptibility

    Directory of Open Access Journals (Sweden)

    Anushen eSivakumaran

    2016-05-01

    Full Text Available Abscisic acid (ABA production has emerged a susceptibility factor in plant-pathogen interactions. This work examined the interaction of ABA with NO in tomato following challenge with the ABA-synthesising pathogen, Botrytis cinerea. Trace gas detection using a quantum cascade laser detected NO production within minutes of challenge with B. cinerea whilst photoacoustic laser detection detected ethylene production – an established mediator of defence against this pathogen - occurring after 6 h. Application of the NO generation inhibitor N-Nitro-L-arginine methyl ester (L-NAME suppressed both NO and ethylene production and resistance against B. cinerea. The tomato mutant sitiens fails to accumulate ABA (abscisic acid, shows increased resistance to B. cinerea and we noted exhibited elevated NO and ethylene production. Exogenous application of L-NAME or ABA reduced NO production in sitiens and reduced resistance to B. cinerea. Increased resistance to B. cinerea in sitiens have previously been linked to increased reactive oxygen species (ROS generation but this was reduced in both L-NAME and ABA treated sitiens. Taken together, our data suggests that ABA can decreases resistance to B. cinerea via reduction of NO production which also suppresses both ROS and ethylene production.

  2. Major latex protein-like protein 43 (MLP43) functions as a positive regulator during abscisic acid responses and confers drought tolerance in Arabidopsis thaliana

    OpenAIRE

    WANG, YANPING; Yang, Li; Chen, Xi; Ye, Tiantian; Zhong, Bao; Liu, Ruijie; Wu, Yan; Chan, Zhulong

    2015-01-01

    Drought stress is one of the disadvantageous environmental conditions for plant growth and reproduction. Given the importance of abscisic acid (ABA) to plant growth and abiotic stress responses, identification of novel components involved in ABA signalling transduction is critical. In this study, we screened numerous Arabidopsis thaliana mutants by seed germination assay and identified a mutant mlp43 (major latex protein-like 43) with decreased ABA sensitivity in seed germination. The mlp43 m...

  3. Sucrose and ABA regulate starch biosynthesis in maize through a novel transcription factor, ZmEREB156

    OpenAIRE

    Huanhuan Huang; Sidi Xie; Qianlin Xiao; Bin Wei; Lanjie Zheng; Yongbin Wang; Yao Cao; Xiangge Zhang; Tiandan Long; Yangping Li; Yufeng Hu; Guowu Yu; Hanmei Liu; Yinghong Liu; Zhi Huang

    2016-01-01

    Sucrose is not only the carbon source for starch synthesis, but also a signal molecule. Alone or in coordination with ABA, it can regulate the expression of genes involved in starch synthesis. To investigate the molecular mechanisms underlying this effect, maize endosperms were collected from Zea mays L. B73 inbred line 10 d after pollination and treated with sucrose, ABA, or sucrose plus ABA at 28 °C in the dark for 24 h. RNA-sequence analysis of the maize endosperm transcriptome revealed 47...

  4. Re-examining the role of ABA as the primary long-distance signal produced by water-stressed roots

    OpenAIRE

    Goodger, Jason QD; Schachtman, Daniel P

    2010-01-01

    The role of ABA as the primary long-distance signal produced by water-stressed roots and transported to stomata continues to be challenged. We have recently reported that expression of ABA biosynthetic genes in roots only increases in the later stage of water stress. Our results support the hypothesis that in early water stress, increased levels of ABA in xylem sap are due to leaf biosynthesis and translocation to roots and from there to xylem. If so, other xylem-borne chemicals may be the pr...

  5. Long-term effects of abscisic acid (ABA) on the grape berry phenylpropanoid pathway: Gene expression and metabolite content.

    Science.gov (United States)

    Villalobos-González, Luis; Peña-Neira, Alvaro; Ibáñez, Freddy; Pastenes, Claudio

    2016-08-01

    ABA has been proposed as the main signal triggering the onset of the ripening process in grapes, and modulating the secondary metabolism in grape berry skins. To determine the effect of ABA on secondary metabolism in berries, clusters of Carménère were sprayed with 0 μLL(-1) ABA; 50 μLL(-1) ABA and 100 μLL(-1) ABA during pre-véraison, and the gene expression of the transcription factors and enzymes of the phenylpropanoid pathway were assessed from véraison to 70 days after véraison (DAV). Additionally, flavonols, tannins and anthocyanins were assessed from véraison until harvest (110 DAV). ABA accelerated sugar and anthocyanin accumulation at véraison. The grape transcript abundance of VvDFR, VvANS, VvUFGT and VvMybA1, all peaking around véraison mimicked the concentration of ABA throughout the season. The highest anthocyanin concentration occurred 35 DAV for all treatments, but higher pigment concentrations were observed in ABA-treated berries at véraison and from 60 to 70 DAV to harvest. VvPAL was also increased by treatment at the higher concentration of ABA from véraison to 40 DAV. Regarding flavanol synthesis, VvLAR2 and VvMyb4A decreased from véraison until 40 DAV and then increased again until 70 DAV. Compared to the control, both ABA treatments resulted in a less-than-proportional reduction of the expression of both genes compared to the control and, after 40 DAV, in a more-than-proportional increase compared to the control, suggesting a long-term effect of the pre-véraison ABA spray on the berries. A concomitant increase in flavanols was observed in berries after 40 DAV, and this occurred at a higher extent in berries treated with the highest ABA concentration. PMID:27116369

  6. Distribution of ABA and AhNCED1 in Peanut Leaves of Different Drought Resistant Cultivars Subjected to Drought Stress%不同花生品种响应干旱胁迫后叶片内ABA与AhNCED1的分布

    Institute of Scientific and Technical Information of China (English)

    胡博; 肖素妮; 吕滟; 李玲

    2012-01-01

    以粤油7号和汕优523两个不同抗旱性品种为材料,研究响应干旱胁迫后叶片ABA(abscisic acid,脱落酸)和AhNCED1 (Arachis hypogaea nine-cis-epoxycarotenoid dioxygenase)的分布以及含量变化.结果表明,两种花生品种响应干旱胁迫后叶片的维管组织中ABA分布增强且含量增加,AhNCED1蛋白分布也增强;且在水分胁迫初期粤油7号花生AhNCED1蛋白分布强于汕优523,其体内ABA分布水平也高于汕优523;经ABA生物合成抑制剂Naproxen处理后,两种花生叶片ABA分布减弱,但粤油7号叶片维管组织中ABA分布水平仍高于汕优523.结果表明维管组织是干旱胁迫下花生叶片中ABA和AhNCED1分布的主要区域,且粤油7号花生抗旱性强可能与其体内AhNCED1和ABA的分布量较高有关.%In this study, the changes of ABA distribution and ABA content in leaf of two species of the peanut (Yueyou 7 and Shanyou 523) were researched through the immunoenzyme localization and ELISA methods. The results showed that the ABA distribution and ABA content in peanut leaf were increased after drought stress. The synthesis of ABA and AhNCED1 in the leaves of Yueyou 7 appeared more quickly than that in the susceptible cultivar (Shanyou 523). Furthermore, AhNCEDl transcript and protein in Yueyou 7 were induced more than that in Shanyou 523, coinciding with higher ABA accumulation. After treated with Naproxen, ABA distribution were lower than that treated with PEG. These results showed that the vascular cambium is the main region of leaf in peanut response to drought stress, and the higher drought-resistant of Yueyou 7 peanut may be relate to the more distribution of ABA and AhNCEDl in leaf.

  7. 干旱胁迫下外源喷施 ABA 对地被菊生理特性的影响%Effect of Application of ABA on Physiological Characteristics of Chry santhemum Under Drought Stress

    Institute of Scientific and Technical Information of China (English)

    李杨; 毛洪玉; 马磊; 谭霖

    2015-01-01

    为探讨外源ABA的化学调控作用,研究了干旱胁迫条件下喷施不同浓度外源激素脱落酸(ABA )对地被菊幼苗生理特性的影响。结果表明:喷施ABA后,地被菊幼苗蒸腾速率(Tr)、气孔导度(Gs)明显下降。外源ABA延缓了叶片相对含水量和叶绿素含量的下降,提高丙二醛和可溶性糖等渗透调节物质的水平,提高了植物的抗旱能力。浓度为100 mg·L ‐1 ABA的处理效果最佳。%In order to explore the chemical control effect of exogenous ABA ,the effect of different concentrations of exogenous ABA on physiological property of Chrysanthemum seedling under drought stress was analyzed . The results showed that after spraying exogenous ABA ,transpiration rate and stomatal conductance decreased , exogenous ABA slowed the decline of leaf relative water content and chlorophyll content ,increased the content of osmotic regulation substances ,such as MDA and soluble sugar ,and improved the resistance to drought .100 mg·L‐1 exogenous ABA performed the best .

  8. Molecular and genetic analyses of the PP2C-ABA receptor interaction in the abscisic acid signaling pathway.

    OpenAIRE

    Antoni Alandes, Regina

    2013-01-01

    La fitohormona ácido abscísico (ABA) juega un papel crucial en el control de la respuesta a estrés y en la regulación del crecimiento y desarrollo de la planta. La unión del ABA a los receptores intracelulares PYR/PYL/RCAR conlleva la inhibición de las PP2Cs del clado A tales como ABI1 o HAB1, causando la activación de la ruta de señalización del ABA. Para obtener más información en la señalización del ABA nos hemos centrado en la caracterización de miembros de estas dos famil...

  9. Antisocial thinking in adolescents: further psychometric development of the Antisocial Beliefs and Attitudes Scale (ABAS).

    Science.gov (United States)

    Butler, Stephen M; Parry, Rachael; Fearon, R M Pasco

    2015-03-01

    Investigating the impact of "off-line" cognitive structures on the broad range of antisocial behaviors shown by young people has been hampered by the absence of psychometrically robust measures of antisocial cognitions. This study evaluates the psychometric properties of the Antisocial Beliefs and Attitudes Scale (ABAS), a developmentally sensitive measure of young people's beliefs and attitudes toward social standards of acceptable behavior at home and at school. The reliability and validity of the ABAS was assessed in a sample of British school children (N = 486) aged 9-16 years (M = 12.79, SD = 1.90) and male young offenders (N = 84) aged 13-17 years (M = 15.15, SD = 0.27). Participants completed the ABAS, together with a self-report measure of antisocial behavior; maternal reports of antisocial activity were also collected in the offending sample. Confirmatory factor analysis replicated the 2-factor structure of Rule Noncompliance and Peer Conflict previously derived from a sample of Canadian school children, and these factors showed good test-retest reliability. Rule Noncompliance predicted self-reported antisocial behavior for ages 11-16 years, while Peer Conflict predicted antisocial behavior for ages 9-16 years. Comparisons between young offenders and an age-matched subsample of males from the school group showed significant differences. In young offenders, Rule Noncompliance and Peer Conflict were significantly predictive of self-reported antisocial behavior, while Rule Noncompliance independently predicted mothers' ratings of their sons' antisocial behavior. These findings provide support for the ABAS as a psychometrically sound measure of antisocial thinking.

  10. ABA mediates PEG-mediated premature differentiation of root apical meristem in plants

    OpenAIRE

    Ji, Hongtao; Li, Xia

    2014-01-01

    Root apical meristem (RAM) is central for indeterminate growth of plant roots and in sensing environmental stimuli, such as water status. Recently, we reported that PEG8000-simulated mild and moderate osmotic stress induces premature differentiation of RAM, which is a conserved adaptive mechanism in higher plants to cope with water stress. Microarray data analysis revealed that the ABA signaling pathway may be involved in water stress-induced RAM premature differentiation. Here we showed that...

  11. Abscisic acid metabolite profiling as indicators of plastic responses to drought in grasses from arid Patagonian Monte (Argentina).

    Science.gov (United States)

    Cenzano, Ana M; Masciarelli, O; Luna, M Virginia

    2014-10-01

    The identification of hormonal and biochemical traits that play functional roles in the adaptation to drought is necessary for the conservation and planning of rangeland management. The aim of this study was to evaluate the effects of drought on i) the water content (WC) of different plant organs, ii) the endogenous level of abscisic acid (ABA) and metabolites (phaseic acid-PA, dihydrophaseic acid-DPA and abscisic acid conjugated with glucose ester-ABA-GE), iii) the total carotenoid concentration and iv) to compare the traits of two desert perennial grasses (Pappostipa speciosa and Poa ligularis) with contrasting morphological and functional drought resistance traits and life-history strategies. Both species were subjected to two levels of gravimetric soil moisture (the highest near field capacity during autumn-winter and the lowest corresponding to summer drought). Drought significantly increased the ABA and DPA levels in the green leaves of P. speciosa and P. ligularis. Drought decreased ABA in the roots of P. speciosa while it increased ABA in the roots of P. ligularis. P. ligularis had the highest ABA level and WC in green leaves. While P. speciosa had the highest DPA levels in leaves. In conclusion, we found the highest ABA level in the mesophytic species P. ligularis and the lowest ABA level in the xerophytic species P. speciosa, revealing that the ABA metabolite profile in each grass species is a plastic response to drought resistance. PMID:25245790

  12. The transcriptional regulatory network in the drought response and its crosstalk in abiotic stress responses including drought, cold, and heat

    OpenAIRE

    Nakashima, Kazuo; Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo

    2014-01-01

    Drought negatively impacts plant growth and the productivity of crops around the world. Understanding the molecular mechanisms in the drought response is important for improvement of drought tolerance using molecular techniques. In plants, abscisic acid (ABA) is accumulated under osmotic stress conditions caused by drought, and has a key role in stress responses and tolerance. Comprehensive molecular analyses have shown that ABA regulates the expression of many genes under osmotic stress cond...

  13. Lipid profiling demonstrates that suppressing Arabidopsis phospholipase Dδ retards ABA-promoted leaf senescence by attenuating lipid degradation.

    Directory of Open Access Journals (Sweden)

    Yanxia Jia

    Full Text Available Senescence is the last phase of the plant life cycle and has an important role in plant development. Degradation of membrane lipids is an essential process during leaf senescence. Several studies have reported fundamental changes in membrane lipids and phospholipase D (PLD activity as leaves senesce. Suppression of phospholipase Dα1 (PLDα1 retards abscisic acid (ABA-promoted senescence. However, given the absence of studies that have profiled changes in the compositions of membrane lipid molecules during leaf senescence, there is no direct evidence that PLD affects lipid composition during the process. Here, we show that application of n-butanol, an inhibitor of PLD, and N-Acylethanolamine (NAE 12∶0, a specific inhibitor of PLDα1, retarded ABA-promoted senescence to different extents. Furthermore, phospholipase Dδ (PLDδ was induced in leaves treated with ABA, and suppression of PLDδ retarded ABA-promoted senescence in Arabidopsis. Lipid profiling revealed that detachment-induced senescence had different effects on plastidic and extraplastidic lipids. The accelerated degradation of plastidic lipids during ABA-induced senescence in wild-type plants was attenuated in PLDδ-knockout (PLDδ-KO plants. Dramatic increases in phosphatidic acid (PA and decreases in phosphatidylcholine (PC during ABA-induced senescence were also suppressed in PLDδ-KO plants. Our results suggest that PLDδ-mediated hydrolysis of PC to PA plays a positive role in ABA-promoted senescence. The attenuation of PA formation resulting from suppression of PLDδ blocks the degradation of membrane lipids, which retards ABA-promoted senescence.

  14. Magnetic Oscillation of Optical Phonon in ABA- and ABC-Stacked Trilayer Graphene

    CERN Document Server

    Cong, Chunxiao; Cao, Bingchen; Qiu, Caiyu; Shen, Xiaonan; Ferreira, Aires; Adam, Shaffique; Yu, Ting

    2015-01-01

    We present a comparative measurement of the G-peak oscillations of phonon frequency, Raman intensity and linewidth in the Magneto-Raman scattering of optical E2g phonons in mechanically exfoliated ABA- and ABC-stacked trilayer graphene (TLG). Whereas in ABA-stacked TLG, we observe magnetophonon oscillations consistent with single-bilayer chiral band doublets, the features are flat for ABC-stacked TLG up to magnetic fields of 9 T. This suppression can be attributed to the enhancement of band chirality that compactifies the spectrum of Landau levels and modifies the magnetophonon resonance properties. The drastically different coupling behaviour between the electronic excitations and the E2g phonons in ABA- and ABC-stacked TLG reflects their different electronic band structures and the electronic Landau level transitions and thus can be another way to determine the stacking orders and to probe the stacking-order-dependent electronic structures. In addition, the sensitivity of the magneto-Raman scattering to the...

  15. Graphene oxide modulates root growth of Brassica napus L. and regulates ABA and IAA concentration.

    Science.gov (United States)

    Cheng, Fan; Liu, Yu-Feng; Lu, Guang-Yuan; Zhang, Xue-Kun; Xie, Ling-Li; Yuan, Cheng-Fei; Xu, Ben-Bo

    2016-04-01

    Researchers have proven that nanomaterials have a significant effect on plant growth and development. To better understand the effects of nanomaterials on plants, Zhongshuang 11 was treated with different concentrations of graphene oxide. The results indicated that 25-100mg/l graphene oxide treatment resulted in shorter seminal root length compared with the control samples. The fresh root weight decreased when treated with 50-100mg/l graphene oxide. The graphene oxide treatment had no significant effect on the Malondialdehyde (MDA) content. Treatment with 50mg/l graphene oxide increased the transcript abundance of genes involved in ABA biosynthesis (NCED, AAO, and ZEP) and some genes involved in IAA biosynthesis (ARF2, ARF8, IAA2, and IAA3), but inhibited the transcript levels of IAA4 and IAA7. The graphene oxide treatment also resulted in a higher ABA content, but a lower IAA content compared with the control samples. The results indicated that graphene oxide modulated the root growth of Brassica napus L. and affected ABA and IAA biosynthesis and concentration. PMID:26945480

  16. Sucrose and ABA regulate starch biosynthesis in maize through a novel transcription factor, ZmEREB156.

    Science.gov (United States)

    Huang, Huanhuan; Xie, Sidi; Xiao, Qianlin; Wei, Bin; Zheng, Lanjie; Wang, Yongbin; Cao, Yao; Zhang, Xiangge; Long, Tiandan; Li, Yangping; Hu, Yufeng; Yu, Guowu; Liu, Hanmei; Liu, Yinghong; Huang, Zhi; Zhang, Junjie; Huang, Yubi

    2016-01-01

    Sucrose is not only the carbon source for starch synthesis, but also a signal molecule. Alone or in coordination with ABA, it can regulate the expression of genes involved in starch synthesis. To investigate the molecular mechanisms underlying this effect, maize endosperms were collected from Zea mays L. B73 inbred line 10 d after pollination and treated with sucrose, ABA, or sucrose plus ABA at 28 °C in the dark for 24 h. RNA-sequence analysis of the maize endosperm transcriptome revealed 47 candidate transcription factors among the differentially expressed genes. We therefore speculate that starch synthetic gene expression is regulated by transcription factors induced by the combination of sucrose and ABA. ZmEREB156, a candidate transcription factor, is induced by sucrose plus ABA and is involved in starch biosynthesis. The ZmEREB156-GFP-fused protein was localized in the nuclei of onion epidermal cells, and ZmEREB156 protein possessed strong transcriptional activation activity. Promoter activity of the starch-related genes Zmsh2 and ZmSSIIIa increased after overexpression of ZmEREB156 in maize endosperm. ZmEREB156 could bind to the ZmSSIIIa promoter but not the Zmsh2 promoter in a yeast one-hybrid system. Thus, ZmEREB156 positively modulates starch biosynthetic gene ZmSSIIIa via the synergistic effect of sucrose and ABA.

  17. Arabidopsis YAK1 regulates abscisic acid response and drought resistance.

    Science.gov (United States)

    Kim, Dongjin; Ntui, Valentine Otang; Xiong, Liming

    2016-07-01

    Abscisic acid (ABA) is an important phytohormone that controls several plant processes such as seed germination, seedling growth, and abiotic stress response. Here, we report that AtYak1 plays an important role in ABA signaling and postgermination growth in Arabidopsis. AtYak1 knockout mutant plants were hyposensitive to ABA inhibition of seed germination, cotyledon greening, seedling growth, and stomatal movement. atyak1-1 mutant plants display reduced drought stress resistance, as evidenced by water loss rate and survival rate. Molecular genetic analysis revealed that AtYak1 deficiency led to elevated expression of stomatal-related gene, MYB60, and down-regulation of several stress-responsive genes. Altogether, these results indicate that AtYak1 plays a role as a positive regulator in ABA-mediated drought response in Arabidopsis. PMID:27264339

  18. Arabidopsis cysteine-rich receptor-like kinase 45 functions in the responses to abscisic acid and abiotic stresses

    KAUST Repository

    Zhang, Xiujuan

    2013-06-01

    The phytohormone abscisic acid (ABA) regulates seed germination, plant growth and development, and response to abiotic stresses such as drought and salt stresses. Receptor-like kinases are well known signaling components that mediate plant responses to developmental and environmental stimuli. Here, we characterized the biological function of an ABA and stress-inducible cysteine-rich receptor-like protein kinase, CRK45, in ABA signaling in Arabidopsis thaliana. The crk45 mutant was less sensitive to ABA than the wild type during seed germination and early seedling development, whereas CRK45 overexpression plants were more sensitive to ABA compared to the wild type. Furthermore, overexpression of CRK45 led to hypersensitivity to salt and glucose inhibition of seed germination, whereas the crk45 mutant showed the opposite phenotypes. In addition, CRK45 overexpression plants had enhanced tolerance to drought. Gene expression analyses revealed that the expression of representative stress-responsive genes was significantly enhanced in CRK45 overexpression plants in response to salt stress. ABA biosynthetic genes such as NCED3,. 22NCED3, 9-Cis-Epoxycarotenoid Dioxygenase 3.NCED5,. 33NCED5, 9-Cis-Epoxycarotenoid Dioxygenase 5.ABA2,. 44ABA2, Abscisic Acid Deficient 2. and AAO355AAO3, Abscisic Aldehyde Oxidase 3. were also constitutively elevated in the CRK45 overexpression plants. We concluded that CRK45 plays an important role in ABA signaling that regulates Arabidopsis seeds germination, early seedling development and abiotic stresses response, by positively regulating ABA responses in these processes. © 2013 Elsevier Masson SAS.

  19. Cloning of 9-cis-epoxycarotenoid dioxygenase (NCED) gene encoding a key enzyme during abscisic acid (ABA) biosynthesis and ABA-regulated ethylene production in detached young persimmon calyx

    Institute of Scientific and Technical Information of China (English)

    LENG Ping; ZHANG GuangLian; LI XiangXin; WANG LiangHe; ZHENG ZhongMing

    2009-01-01

    Unlike the typical climacteric fruits,persimmons (Diospyros kaki Thunb.) produce higher levels of ethylene when they are detached from trees at a younger stage.In order to obtain detailed information on the role of abscisic acid (ABA) in ripening,we cloned the DKNCED1,DKACS2,and DKAC01 genes from the calyx.Water loss was first noted in the calyx lobe,and DKNCED1 was highly expressed 1 d after the fruits were detached,coinciding with an increase in the ABA content.Then,the DKACS2 and DKAC01 genes were expressed after some delay.In the calyx,the ABA peak was observed 2 d after the fruits were harvested,and this peak preceded the ethylene peak observed on day 3.The fruit firmness rapidly decreased on day 4,and the fruits softened completely 6 d after they were harvested.The increases in the expressions of ABA,ethylene,and the genes in the calyxes occurred earlier than the corresponding increases in the pulp,although the 3 increases occurred on different days.Exogenous ABA treatment increased ABA concentration,induced expression of both ACS and ACO,and promoted ethylene synthesis and young-fruit softening;by contrast,treatment with NDGA inhibited the gene expressions and ethylene synthesis and delayed young-fruit softening.These results indicate that ethylene biosynthesis in the detached young persimmon fruits is initially triggered by ABA,which is induced by water loss in the calyx,through the induction of DKACS2 and DKAC01 expressions.The ethylene produced in the calyx subsequently diffuses into the pulp tissue,where it induces autocatalytic ethylene biosynthesis,resulting in an abrupt increase in ethylene production.

  20. Up-regulating the abscisic acid inactivation gene ZmABA8ox1b contributes to seed germination heterosis by promoting cell expansion.

    Science.gov (United States)

    Li, Yangyang; Wang, Cheng; Liu, Xinye; Song, Jian; Li, Hongjian; Sui, Zhipeng; Zhang, Ming; Fang, Shuang; Chu, Jinfang; Xin, Mingming; Xie, Chaojie; Zhang, Yirong; Sun, Qixin; Ni, Zhongfu

    2016-04-01

    Heterosis has been widely used in agriculture, but the underlying molecular principles are still largely unknown. During seed germination, we observed that maize (Zea mays) hybrid B73/Mo17 was less sensitive than its parental inbred lines to exogenous abscisic acid (ABA), and endogenous ABA content in hybrid embryos decreased more rapidly than in the parental inbred lines. ZmABA8ox1b, an ABA inactivation gene, was consistently more highly up-regulated in hybrid B73/Mo17 than in its parental inbred lines at early stages of seed germination. Moreover, ectopic expression of ZmABA8ox1b obviously promoted seed germination in Arabidopsis Remarkably, microscopic observation revealed that cell expansion played a major role in the ABA-mediated maize seed germination heterosis, which could be attributed to the altered expression of cell wall-related genes. PMID:27034328

  1. The putative E3 ubiquitin ligase ECERIFERUM9 regulates abscisic acid biosynthesis and response during seed germination and postgermination growth in arabidopsis

    KAUST Repository

    Zhao, Huayan

    2014-05-08

    The ECERIFERUM9 (CER9) gene encodes a putative E3 ubiquitin ligase that functions in cuticle biosynthesis and the maintenance of plant water status. Here, we found that CER9 is also involved in abscisic acid (ABA) signaling in seeds and young seedlings of Arabidopsis (Arabidopsis thaliana). The germinated embryos of the mutants exhibited enhanced sensitivity to ABA during the transition from reversible dormancy to determinate seedling growth. Expression of the CER9 gene is closely related to ABA levels and displays a similar pattern to that of ABSCISIC ACID-INSENSITIVE5 (ABI5), which encodes a positive regulator of ABA responses in seeds. cer9 mutant seeds exhibited delayed germination that is independent of seed coat permeability. Quantitative proteomic analyses showed that cer9 seeds had a protein profile similar to that of the wild type treated with ABA. Transcriptomics analyses revealed that genes involved in ABA biosynthesis or signaling pathways were differentially regulated in cer9 seeds. Consistent with this, high levels of ABA were detected in dry seeds of cer9. Blocking ABA biosynthesis by fluridone treatment or by combining an ABA-deficient mutation with cer9 attenuated the phenotypes of cer9. Whereas introduction of the abi1-1, abi3-1, or abi4-103 mutation could completely eliminate the ABA hypersensitivity of cer9, introduction of abi5 resulted only in partial suppression. These results indicate that CER9 is a novel negative regulator of ABA biosynthesis and the ABA signaling pathway during seed germination. © 2014 American Society of Plant Biologists. All Rights Reserved.

  2. Sequence Variation and Expression Analysis of Seed Dormancy- and Germination-Associated ABA- and GA-Related Genes in Rice Cultivars

    OpenAIRE

    Liu, Fei; Zhang, Hangxiao; Wu, Gang; Sun, Jing; Hao, Lili; Ge, Xiaomeng; Yu, Jun; Wang, Weiwei

    2011-01-01

    Abscisic acid (ABA) and Gibberellic acid (GA) play key roles in regulating seed dormancy and germination. First, when examining germination of different rice cultivars, we found that their germination timing and dormancy status are rather distinct, coupled with different GA/ABA ratio. Second, we studied genomic sequences of ABA and GA dormancy- and germination-associated genes in rice and discovered single nucleotide polymorphisms and insertions/deletions (Indels) in both coding and regulator...

  3. The barley HvNAC6 transcription factor affects ABA accumulation and promotes basal resistance against powdery mildew

    DEFF Research Database (Denmark)

    Chen, Yan-Jun; Perera, Venura; Wagner, Michael;

    2013-01-01

    /dark rhythm of ABA levels which were, however, not influenced by Bgh inoculation. The expression of the two ABA biosynthetic genes HvNCED1 and HvNCED2 was compromised, and transcript levels of the ABA conjugating HvBG7 enzyme were elevated in the HvNAC6 RNAi lines, but this effect was not clearly associated...

  4. Xylem sap collection and extraction methodologies to determine in vivo concentrations of ABA and its bound forms by gas chromatography-mass spectrometry (GC-MS)

    OpenAIRE

    Netting Andrew G; Theobald Julian C; Dodd Ian C

    2012-01-01

    Abstract Background Accurate quantification of xylem sap ABA concentrations is important to underpin models of root-to-shoot ABA signalling to predict the physiological effects of soil drying. Growing tomato plants in a whole plant pressure chamber allowed sequential xylem sap collection from a detached leaf, the petiole stub of an otherwise intact plant and finally the de-topped root system of the same plant, to determine the impact of xylem sap sampling methodology on xylem ABA concentratio...

  5. The role of abscisic and acid in disturbed stomatal response characteristics of tradescantia virginiana during growth at high relative air humidity

    NARCIS (Netherlands)

    Rezaei Nejad, A.; Meeteren, van U.

    2007-01-01

    In this study, the role of abscisic acid (ABA) in altered stomatal responses of Tradescantia virginiana leaves grown at high relative air humidity (RH) was investigated. A lower ABA concentration was found in leaves grown at high RH compared with leaves grown at moderate RH. As a result of a daily a

  6. Research progress of plant PP2C-type protein phosphatase in ABA signal transduction and adversity stress regulation mechanism%植物 PP2C 蛋白磷酸酶 ABA 信号转导及逆境胁迫调控机制研究进展

    Institute of Scientific and Technical Information of China (English)

    张继红; 陶能国

    2015-01-01

    Protein phosphatase is the most important and pivotal enzymes in reversible protein phosphorylation regula-ting mechanisms.While the PP2C phosphatase is a kind of serine/threonine residues of protein phosphatase,is the largest protein phosphatase family in higher plants,there are 76 family members,widely exists in living organisms. So far,four kinds of PP2C protein phosphatases have been found in plants.Protein kinase and protein phosphatase catalyzed reversible protein phosphorylation,play an important role in plant signal transduction and physiological me-tabolism,protein phosphorylation exist in almost the signal transduction pathway.Numerous academic studies have shown that plant PP2Cs are involved in multiple signal transduction pathways including PP 2C involved in ABA sig-naling pathway,the response to drought,low temperature,salt stress,participated in the plant wound and seed dor-mancy or germination signal pathway,and exist the different regulation mechanism and the enzyme catalytic activity were dependent on the concentrations of Mg2+ or Mn2+ .In plant PP2Cs protein C-terminal,there are a highly con-served catalytic domains,as well as in their N-terminal,their function are different.The review would provide a brief overview of classification,structure of PP 2Cs ,the interaction between ABA receptor and PP2Cs protein,the recent progresses about their roles in ABA and other stress signal transduction pathway in higher plant.%蛋白磷酸酶(protein phosphatase,PP)是蛋白质可逆磷酸化调节机制中的关键酶,而 PP2C 磷酸酶是一类丝氨酸/苏氨酸残基蛋白磷酸酶,是高等植物中最大的蛋白磷酸酶家族,包含76个家族成员,广泛存在于生物体中。迄今为止,在植物体内已经发现了4种 PP2C 蛋白磷酸酶。蛋白激酶和蛋白磷酸酶协同催化蛋白质可逆磷酸化,在植物体内信号转导和生理代谢中起着重要的调节作用,蛋白质的磷酸化几乎存在于所有的信号转导途

  7. Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture

    OpenAIRE

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

    2008-01-01

    When soil moisture is heterogeneous, sap flow from, and ABA status of, different parts of the root system impact on leaf xylem ABA concentration ([X-ABA]leaf). The robustness of a model for predicting [X-ABA]leaf was assessed. ‘Two root-one shoot’ grafted sunflower (Helianthus annuus L.) plants received either deficit irrigation (DI, each root system received the same irrigation volumes) or partial rootzone drying (PRD, only one root system was watered and the other dried the soil). Irrespect...

  8. Study on the Change of GAs,ABA Level and ABA/GAs Ratio in the Embryos of Spring Wheat and Winter Wheat During Vernalization

    Institute of Scientific and Technical Information of China (English)

    MiGuohua; LiWenxong

    1995-01-01

    Spring wheat(cv.7742)and winter wheat (cv.Nongda 015) were vernalized by seed chilling,and the changes of GAs,ABA content and GAs/ABA ration in embryo wer investigated.The differences between cultivars,treatments and variety-treatment inleractions were significant for both GAs and ABA.The level of GAs and ABA as well as GAs/ABA ratio were hardly changed by seed chilling in spriug wheat Howerve,in winter wheat,the GAs content decreased much less compared with ABA that reduced sharply after chilling.It showed that the GAs/ABA ratio in winter wheat was increased remarkably(4.55 times)than in spring wheat.It was suggested that the absolute GAs Ievel was independent of the vernalization effect because there was a higher GAs Level before and after seed chilling in winter wheat when compared with spring wheat,One of the vemalization effects was the decline of ABA level that led to the increase of GAs/ABA ratio.

  9. StudyonCollegeTourismEnglishTeaching CombiningwithAbaLocalTourismCulture

    Institute of Scientific and Technical Information of China (English)

    苗琴

    2013-01-01

    Boasting of rich, outstanding natural and cultural tourism resources, marvelous landscape, specific humanistic environment,AbaTibetanandQiangAutonomousPrefectureiswell-known to the world, which has been attracting ever-increasing touristshomeandabroadwithitsuniquecharm,suchasthefairy-landlikenaturalscenery,mysteriousTibetanBuddhistculture, ancient Qiang’s Shibi (necromancer) culture, the Red Army’s LongMarchcultureandsoon.Theserichnaturalandcultural tourismresourcesraisetheeconomicbenefitsofculturaltourism developmentemphasis.Abaisanethnicminorityarealeadingwith the tourism industry; after years of development, tourism has becomethemainsourceofincomeforthelocalethnicminorities. Moreandmoreforeigntouristshavebeenattractedintothisarea, particularly,Europe,theUnitedStatesandotherEnglish-speaking countrieshavebecomethemajorsourcecountries; alargenumberof high-qualifiedtourismprofessionalsareinurgentneed,andtourism EnglishteachingplaysaveryimportantroleforcultivatingHigh qualitytalentswhoarebothproficientinEnglish,graspinghigh leveltourismskills,andquitefamiliarwithAbatourismresources. Thispaperanalyzesandputsforwardsomeconstructivemeasureson howtocombineAbatourismresources,localculturewithcollege tourismEnglishteaching.

  10. Forest Parameter Prediction Using an Image-Based Point Cloud: A Comparison of Semi-ITC with ABA

    Directory of Open Access Journals (Sweden)

    Johannes Rahlf

    2015-11-01

    Full Text Available Image-based point clouds obtained using aerial photogrammetry share many characteristics with point clouds obtained by airborne laser scanning (ALS. Two approaches have been used to predict forest parameters from ALS: the area-based approach (ABA and the individual tree crown (ITC approach. In this article, we apply the semi-ITC approach, a variety of the ITC approach, on an image-based point cloud to predict forest parameters and compare the performance to the ABA. Norwegian National Forest Inventory sample plots on a site in southeastern Norway were used as the reference data. Tree crown objects were delineated using a watershed segmentation algorithm, and explanatory variables were calculated for each tree crown segment. A multivariate kNN model for timber volume, stem density, basal area and quadratic mean diameter with the semi-ITC approach produced RMSEs of 30%, 46%, 25%, 26%, respectively. The corresponding measures for the ABA were 30%, 51%, 26%, 35%, respectively. Univariate kNN models resulted in timber volume RMSEs of 25% for the semi-ITC approach and 22% for the ABA. A non-linear logistic regression model with the ABA produced an RMSE of 23%. Both approaches predicted timber volume with comparable precision and accuracy at the plot level. The multivariate kNN model was slightly more precise with the semi-ITC approach, while biases were larger

  11. Protein phosphorylation is involved in the water stress induced ABA accumulation in the roots of Malus hupehensis Rehd

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Water stress-induced ABA accumulation plays a key role in the root to shoot communication and/or the cell to cell signaling under the soil stresses. The signaling of the water stress itself that leads to the accumulation, however, is less known. In this study, we subjected the roots of Malus hupehensis seedlings to water stress treatment and investigated the ABA accumulation in relation to protein phosphorylation. Our results showed that ABA accumulation could be substantially triggered in 40 min and reached 4 folds in 100 min after treatment with 30% PEG 6000 (polyethylene glycol). The water stress treatment also led to a substantial enhancement of total kinase activity, assessed with histone-Ⅲ as substrate, in 15 min and a maximum enhancement in 30 min before it declined to initial level. The Ca2+-dependent kinase activity showed a similar, if not more sensitive, trend. When the roots were fed with labeled 32pATP, water stress enhanced the labeling of proteins, which showed a maximum labeling at 40 min. Two inhibitors of protein kinases, Quercetin and H7, effectively diminished or completely blocked the ABA accumulation under the stress treatment. It is therefore suggest that protein phosphorylation is involved in the signaling of the water stress-induced ABA accumulation.

  12. ModABa Model: Annual Flow Duration Curves Assessment in Ephemeral Basins

    Science.gov (United States)

    Pumo, Dario; Viola, Francesco; Noto, Leonardo V.

    2013-04-01

    A representation of the streamflow regime for a river basin is required for a variety of hydrological analyses and engineering applications, from the water resource allocation and utilization to the environmental flow management. The flow duration curve (FDC) represents a comprehensive signature of temporal runoff variability often used to synthesize catchment rainfall-runoff responses. Several models aimed to the theoretical reconstruction of the FDC have been recently developed under different approaches, and a relevant scientific knowledge specific to this topic has been already acquired. In this work, a new model for the probabilistic characterization of the daily streamflows in perennial and ephemeral catchments is introduced. The ModABa model (MODel for Annual flow duration curves assessment in intermittent BAsins) can be thought as a wide mosaic whose tesserae are frameworks, models or conceptual schemes separately developed in different recent studies. Such tesserae are harmoniously placed and interconnected, concurring together towards a unique final aim that is the reproduction of the FDC of daily streamflows in a river basin. Two separated periods within the year are firstly identified: a non-zero period, typically characterized by significant streamflows, and a dry period, that, in the cases of ephemeral basins, is the period typically characterized by absence of streamflow. The proportion of time the river is dry, providing an estimation of the probability of zero flow occurring, is empirically estimated. Then, an analysis concerning the non-zero period is performed, considering the streamflow disaggregated into a slow subsuperficial component and a fast superficial component. A recent analytical model is adopted to derive the non zero FDC relative to the subsuperficial component; this last is considered to be generated by the soil water excess over the field capacity in the permeable portion of the basin. The non zero FDC relative to the fast

  13. Overexpression of the NDR1/HIN1-Like Gene NHL6 Modifies Seed Germination in Response to Abscisic Acid and Abiotic Stresses in Arabidopsis.

    Science.gov (United States)

    Bao, Yan; Song, Wei-Meng; Pan, Jing; Jiang, Chun-Mei; Srivastava, Renu; Li, Bei; Zhu, Lu-Ying; Su, Hong-Yan; Gao, Xiao-Shu; Liu, Hua; Yu, Xiang; Yang, Lei; Cheng, Xian-Hao; Zhang, Hong-Xia

    2016-01-01

    NHL (NDR1/HIN1-like) genes play crucial roles in pathogen induced plant responses to biotic stress. Here, we report the possible function of NHL6 in plant response to abscisic acid (ABA) and abiotic stress. NHL6 was highly expressed in non-germinated seeds, and its expression was strongly induced by ABA and multiple abiotic stress signals. Loss-of-function of NHL6 decreased sensitivity to ABA in the early developmental stages including seed germination and post-germination seedling growth of the nhl6 mutants. However, overexpression of NHL6 increased sensitivity to ABA, salt and osmotic stress of the transgenic plants. Further studies indicated that the increased sensitivity in the 35S::NHL6 overexpressing plants could be a result of both ABA hypersensitivity and increased endogenous ABA accumulation under the stress conditions. It was also seen that the ABA-responsive element binding factors AREB1, AREB2 and ABF3 could regulate NHL6 expression at transcriptional level. Our results indicate that NHL6 plays an important role in the abiotic stresses-induced ABA signaling and biosynthesis, particularly during seed germination and early seedling development in Arabidopsis.

  14. Stomatal guard cells co-opted an ancient ABA-dependent desiccation survival system to regulate stomatal closure.

    Science.gov (United States)

    Lind, Christof; Dreyer, Ingo; López-Sanjurjo, Enrique J; von Meyer, Katharina; Ishizaki, Kimitsune; Kohchi, Takayuki; Lang, Daniel; Zhao, Yang; Kreuzer, Ines; Al-Rasheid, Khaled A S; Ronne, Hans; Reski, Ralf; Zhu, Jian-Kang; Geiger, Dietmar; Hedrich, Rainer

    2015-03-30

    During the transition from water to land, plants had to cope with the loss of water through transpiration, the inevitable result of photosynthetic CO2 fixation on land [1, 2]. Control of transpiration became possible through the development of a new cell type: guard cells, which form stomata. In vascular plants, stomatal regulation is mediated by the stress hormone ABA, which triggers the opening of the SnR kinase OST1-activated anion channel SLAC1 [3, 4]. To understand the evolution of this regulatory circuit, we cloned both ABA-signaling elements, SLAC1 and OST1, from a charophyte alga, a liverwort, and a moss, and functionally analyzed the channel-kinase interactions. We were able to show that the emergence of stomata in the last common ancestor of mosses and vascular plants coincided with the origin of SLAC1-type channels capable of using the ancient ABA drought signaling kinase OST1 for regulation of stomatal closure. PMID:25802151

  15. Introduction of Pinus radiata for afforestation: a review with reference to Aba, China

    Institute of Scientific and Technical Information of China (English)

    BIHui-quan; JackSimpson; LIRong-wei; YANHong; WUZong-xing; CAIShi-min; RobertEldridge

    2003-01-01

    Pinus radiata D. Don, native to a Californian coastal environment, has been introduced to many parts of the world as an exotic species for afforestation. It is now a major plantation species in the Southern Hemisphere. In 1990, it was introduced to the heavily degraded, dry Min river valley area in Aba prefecture of Sichuan Province, P. R. China. Survival and growth of young trees planted at several sites appear to be reasonable. This review is to serve as an introduction to the large body of literature on P.radiata for forest scientists in China. It covers the following aspects: P. radiata in its native environment and in ex situ plantations,provenance and genetic variations, environmental limitations and climate niche, diseases and pests, lessons from unsuccessful introductions, and the use of P. radiata for ecological restoration. The early growth of P. radiata planted in the dry river valley area is briefly described. Potential problems associated with the introduction of P. radiata in Aba and future research needs are also identified.

  16. The small ethylene response factor ERF96 is involved in the regulation of the abscisic acid response in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Xiaoping eWang

    2015-11-01

    Full Text Available Ethylene regulates many aspects of plant growth and development including seed germination, leaf senescence, and fruit ripening, and of plant responses to environmental stimuli including both biotic and abiotic stresses. Ethylene Response Factors (ERFs are plant-specific transcription factors and are a subfamily of the AP2 (APETALA2/ERF transcription factor family. The function of many members in this large gene family remains largely unknown. ERF96, a member of the Group IX ERF family transcription factors, has recently been shown to be a transcriptional activator that is involved in plant defense response in Arabidopsis. Here we provide evidence that ERF96 is a positive regulator of abscisic acid (ABA responses. Bioinformatics analysis indicated that there are a total four small ERFs in Arabidopsis including ERF95, ERF96, ERF97 and ERF98, and that ERF96 forms a cluster with ERF95 and ERF97. By using quantitative RT-PCR, we found that ERF96 is expressed in all tissues and organs examined except roots, with relatively high expression in flowers and seeds. Results from the protoplast transfection assay results indicated that the EDLL motif-containing C-terminal domain is responsible for ERF96’s transcriptional activity. Although loss-of-function mutant of ERF96 was morphologically similar to wild type plants, transgenic plants overexpressing ERF96 had smaller rosette size and were delayed in flowering time. In ABA sensitivity assays, we found that ERF96 overexpression plants were hypersensitive to ABA in terms of ABA inhibition of seed germination, early seedling development and root elongation. Consistent with these observations, elevated transcript levels of some ABA-responsive genes including RD29A, ABI5, ABF3, ABF4, P5CS and COR15A were observed in the transgenic plants in the presence of ABA. However, in the absence of ABA treatment, the transcript levels of these ABA-responsive genes remained largely unchanged. Our experiments also showed

  17. Major latex protein-like protein 43 (MLP43) functions as a positive regulator during abscisic acid responses and confers drought tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Wang, Yanping; Yang, Li; Chen, Xi; Ye, Tiantian; Zhong, Bao; Liu, Ruijie; Wu, Yan; Chan, Zhulong

    2016-01-01

    Drought stress is one of the disadvantageous environmental conditions for plant growth and reproduction. Given the importance of abscisic acid (ABA) to plant growth and abiotic stress responses, identification of novel components involved in ABA signalling transduction is critical. In this study, we screened numerous Arabidopsis thaliana mutants by seed germination assay and identified a mutant mlp43 (major latex protein-like 43) with decreased ABA sensitivity in seed germination. The mlp43 mutant was sensitive to drought stress while the MLP43-overexpressed transgenic plants were drought tolerant. The tissue-specific expression pattern analysis showed that MLP43 was predominantly expressed in cotyledons, primary roots and apical meristems, and a subcellular localization study indicated that MLP43 was localized in the nucleus and cytoplasm. Physiological and biochemical analyses indicated that MLP43 functioned as a positive regulator in ABA- and drought-stress responses in Arabidopsis through regulating water loss efficiency, electrolyte leakage, ROS levels, and as well as ABA-responsive gene expression. Moreover, metabolite profiling analysis indicated that MLP43 could modulate the production of primary metabolites under drought stress conditions. Reconstitution of ABA signalling components in Arabidopsis protoplasts indicated that MLP43 was involved in ABA signalling transduction and acted upstream of SnRK2s by directly interacting with SnRK2.6 and ABF1 in a yeast two-hybrid assay. Moreover, ABA and drought stress down-regulated MLP43 expression as a negative feedback loop regulation to the performance of MLP43 in ABA and drought stress responses. Therefore, this study provided new insights for interpretation of physiological and molecular mechanisms of Arabidopsis MLP43 mediating ABA signalling transduction and drought stress responses.

  18. Effects of ABA Content on the Development of Abscission Zone and Berry Falling After Harvesting of Grapes

    Institute of Scientific and Technical Information of China (English)

    ZHANG You-lin; ZHANG Run-guang

    2009-01-01

    The commodity price of grape reduces as berry falling after harvest. It is crucial to prevent grape from berry falling during storage. In this article, the structure change of grape cells in the abscission zone was observed, the ABA content and the activities of cellulase and polygalacturonase (PG) were measured, and the relationship of ABA and berry falling was investigated. The results suggest that cells in the abscission zone grow into a separation layer soon after the grapes are cut off. According to the level of development, we designed 6 grades to sort the different development stages. The grade 3 plays an important role in berry falling. ABA enhances the activities of cellulase and polygalacturonase, and accelerates the decomposition of cellulose and pectin, which determines the level of development of abscission zone and berry falling. If ABA ratio is less than 20 ng g-1 fresh weight (FW), the abscission zone is not developed to the grade 3, and the berry falling is effectively stopped. We treated grape bunches with nine plant growth regulators and two chemicals. The results indicated that 2,3,5-triiodobenzoic acid (TIBA) can (a) inhibit the generation of ABA significantly, (b) inactivate the activities of cellulase and PG, (c) delay the development of the grade 3 of abscission zone, and (d) stop berry falling. Indole acetic acid (IAA), gibberellic acid (GA3), naphthalene acetic acid (NAA), 6-benzylaminopurine (6-BA), calcium chloride (CaCl2), and potassium permanganate (KMnO4) caused similar results as TIBA. Chlorocholine chloride (CCC), dimethyl amino succinamic acid (B9), chloroethylphosphonic acid (CEPA) and exogenous ABA showed opposite effects.

  19. Auxin and ABA act as central regulators of developmental networks associated with paradormancy in Canada thistle (Cirsium arvense)

    KAUST Repository

    Anderson, James V.

    2012-05-13

    Abstract Dormancy in underground vegetative buds of Canada thistle, an herbaceous perennial weed, allows escape from current control methods and contributes to its invasive nature. In this study, ∼65 % of root sections obtained from greenhouse propagated Canada thistle produced new vegetative shoots by 14 days post-sectioning. RNA samples obtained from sectioned roots incubated 0, 24, 48, and 72 h at 25°C under 16:8 h light-dark conditions were used to construct four MID-tagged cDNA libraries. Analysis of in silico data obtained using Roche 454 GS-FLX pyrosequencing technologies identified molecular networks associated with paradormancy release in underground vegetative buds of Canada thistle. Sequencing of two replicate plates produced ∼2.5 million ESTs with an average read length of 362 bases. These ESTs assembled into 67358 unique sequences (21777 contigs and 45581 singlets) and annotation against the Arabidopsis database identified 15232 unigenes. Among the 15232 unigenes, we identified processes enriched with transcripts involved in plant hormone signaling networks. To follow-up on these results, we examined hormone profiles in roots, which identified changes in abscisic acid (ABA) and ABA metabolites, auxins, and cytokinins post-sectioning. Transcriptome and hormone profiling data suggest that interaction between auxin- and ABA-signaling regulate paradormancy maintenance and release in underground adventitious buds of Canada thistle. Our proposed model shows that sectioning-induced changes in polar auxin transport alters ABA metabolism and signaling, which further impacts gibberellic acid signaling involving interactions between ABA and FUSCA3. Here we report that reduced auxin and ABA-signaling, in conjunction with increased cytokinin biosynthesis post-sectioning supports a model where interactions among hormones drives molecular networks leading to cell division, differentiation, and vegetative outgrowth. ©Springer-Verlag (outside the USA) 2012.

  20. Genome-Wide Analysis of the bZIP Gene Family Identifies Two ABI5-Like bZIP Transcription Factors, BrABI5a and BrABI5b, as Positive Modulators of ABA Signalling in Chinese Cabbage.

    Directory of Open Access Journals (Sweden)

    Yili Bai

    Full Text Available bZIP (basic leucine zipper transcription factors coordinate plant growth and development and control responses to environmental stimuli. The genome of Chinese cabbage (Brassica rapa encodes 136 putative bZIP transcription factors. The bZIP transcription factors in Brassica rapa (BrbZIP are classified into 10 subfamilies. Phylogenetic relationship analysis reveals that subfamily A consists of 23 BrbZIPs. Two BrbZIPs within subfamily A, Bra005287 and Bra017251, display high similarity to ABI5 (ABA Insensitive 5. Expression of subfamily A BrbZIPs, like BrABI5a (Bra005287/BrbZIP14 and BrABI5b (Bra017251/BrbZIP13, are significantly induced by the plant hormone ABA. Subcellular localization assay reveal that both BrABI5a and BrABI5b have a nuclear localization. BrABI5a and BrABI5b could directly stimulate ABA Responsive Element-driven HIS (a HIS3 reporter gene, which confers His prototrophy or LUC (LUCIFERASE expression in yeast and Arabidopsis protoplast. Deletion of the bZIP motif abolished BrABI5a and BrABI5b transcriptional activity. The ABA insensitive phenotype of Arabidopsis abi5-1 is completely suppressed in transgenic lines expressing BrABI5a or BrABI5b. Overall, these results suggest that ABI5 orthologs, BrABI5a and BrABI5b, have key roles in ABA signalling in Chinese cabbage.

  1. Genome-Wide Analysis of the bZIP Gene Family Identifies Two ABI5-Like bZIP Transcription Factors, BrABI5a and BrABI5b, as Positive Modulators of ABA Signalling in Chinese Cabbage

    Science.gov (United States)

    Hu, Xiaochen; Sun, Congcong; Li, Yanlin; Wang, Dandan; Wang, Qinhu; Pei, Guoliang; Zhang, Yanfeng; Guo, Aiguang; Zhao, Huixian; Lu, Haibin; Mu, Xiaoqian; Hu, Jingjiang; Zhou, Xiaona; Xie, Chang Gen

    2016-01-01

    bZIP (basic leucine zipper) transcription factors coordinate plant growth and development and control responses to environmental stimuli. The genome of Chinese cabbage (Brassica rapa) encodes 136 putative bZIP transcription factors. The bZIP transcription factors in Brassica rapa (BrbZIP) are classified into 10 subfamilies. Phylogenetic relationship analysis reveals that subfamily A consists of 23 BrbZIPs. Two BrbZIPs within subfamily A, Bra005287 and Bra017251, display high similarity to ABI5 (ABA Insensitive 5). Expression of subfamily A BrbZIPs, like BrABI5a (Bra005287/BrbZIP14) and BrABI5b (Bra017251/BrbZIP13), are significantly induced by the plant hormone ABA. Subcellular localization assay reveal that both BrABI5a and BrABI5b have a nuclear localization. BrABI5a and BrABI5b could directly stimulate ABA Responsive Element-driven HIS (a HIS3 reporter gene, which confers His prototrophy) or LUC (LUCIFERASE) expression in yeast and Arabidopsis protoplast. Deletion of the bZIP motif abolished BrABI5a and BrABI5b transcriptional activity. The ABA insensitive phenotype of Arabidopsis abi5-1 is completely suppressed in transgenic lines expressing BrABI5a or BrABI5b. Overall, these results suggest that ABI5 orthologs, BrABI5a and BrABI5b, have key roles in ABA signalling in Chinese cabbage. PMID:27414644

  2. Genome-Wide Analysis of the bZIP Gene Family Identifies Two ABI5-Like bZIP Transcription Factors, BrABI5a and BrABI5b, as Positive Modulators of ABA Signalling in Chinese Cabbage.

    Science.gov (United States)

    Bai, Yili; Zhu, Wenbo; Hu, Xiaochen; Sun, Congcong; Li, Yanlin; Wang, Dandan; Wang, Qinhu; Pei, Guoliang; Zhang, Yanfeng; Guo, Aiguang; Zhao, Huixian; Lu, Haibin; Mu, Xiaoqian; Hu, Jingjiang; Zhou, Xiaona; Xie, Chang Gen

    2016-01-01

    bZIP (basic leucine zipper) transcription factors coordinate plant growth and development and control responses to environmental stimuli. The genome of Chinese cabbage (Brassica rapa) encodes 136 putative bZIP transcription factors. The bZIP transcription factors in Brassica rapa (BrbZIP) are classified into 10 subfamilies. Phylogenetic relationship analysis reveals that subfamily A consists of 23 BrbZIPs. Two BrbZIPs within subfamily A, Bra005287 and Bra017251, display high similarity to ABI5 (ABA Insensitive 5). Expression of subfamily A BrbZIPs, like BrABI5a (Bra005287/BrbZIP14) and BrABI5b (Bra017251/BrbZIP13), are significantly induced by the plant hormone ABA. Subcellular localization assay reveal that both BrABI5a and BrABI5b have a nuclear localization. BrABI5a and BrABI5b could directly stimulate ABA Responsive Element-driven HIS (a HIS3 reporter gene, which confers His prototrophy) or LUC (LUCIFERASE) expression in yeast and Arabidopsis protoplast. Deletion of the bZIP motif abolished BrABI5a and BrABI5b transcriptional activity. The ABA insensitive phenotype of Arabidopsis abi5-1 is completely suppressed in transgenic lines expressing BrABI5a or BrABI5b. Overall, these results suggest that ABI5 orthologs, BrABI5a and BrABI5b, have key roles in ABA signalling in Chinese cabbage. PMID:27414644

  3. Transport and concentration of abscisic acid (ABA) and auxin (IAA) in deciduous and coniferous trees. Transport und Gehalt von Abscisinsaeure (ABA) und Auxin (IAA) in Laub- und Nadelblaettern

    Energy Technology Data Exchange (ETDEWEB)

    Hartung, W.

    1988-09-01

    Abscisic acid and indoleacetic acid were chosen to examine whether intact deciduous and coniferous tissues from spruce, hemlock fir, spinage, barley and sorrel or isolated mesophyll protoplasts from barley and closing cell preparations from Valerianella locusta are affected by sulphur dioxide in terms of changes in the concentration, transportation and distribution of such plant hormones. The distribution of phytohormones like ABA and IAA over the individual cell compartments is determined by the different pH gradients of the latter. Owing to their acidity these hormones are accumulated in alkaline cell inclusion bodies like chloroplasts and cytosol. Potentially acid air pollutants like SO{sub 2} and NO{sub x} lead to acidification of previously alkaline cell compartments, due to which fact the cellular pH gradients are reduced. This, in turn, gives rise to a redistribution of phytohormones to the effect that certain target cells such as closing cells of leaves or meristem cells come under the influence of altered hormone concentrations and compositions. This is bound to affect the processes controlling the development, growth and stress behaviour of plants. (orig.) With 55 refs., 2 tabs., 16 figs.

  4. Analysis of Physiological Characteristics about ABA Alleviating Rice Booting Stage Drought Stress%ABA缓解水稻孕穗期干旱胁迫生理特性的分析

    Institute of Scientific and Technical Information of China (English)

    郭贵华; 刘海艳; 李刚华; 刘明; 李岩; 王绍华; 刘正辉; 唐设; 丁艳锋

    2014-01-01

    慢;对ABA较钝感,ABA虽显著提高南粳44干旱胁迫时穗粒数、结实率与千粒重,但未显著提高每盆产量。结论 ABA对水稻具有短期“休眠”的效果,能够有效缓解孕穗期干旱胁迫对水稻生理代谢功能的损伤,促进复水后的功能修复,减轻干旱对产量的影响。抗旱性不同的水稻对ABA的响应存在差异性,抗旱性越强的品种,对ABA越敏感,喷施ABA作用越明显。%[Objective]The objective of the study is to reveal the drought tolerance mechanisms of different rice varieties and the physiological mechanisms about ABA reliving rice drought stress.[Method]Japonica drought tolerance rice Zaoyuxiangjing and conventional japonica rice Nanjing44 were pot planted until booting stage, and 150 mg·kg-1 of abscisic acid (ABA) was sprayed on leaf to study the influence on rice antioxidant enzyme activity (SOD, CAT), membrane lipid peroxidation (MDA) content, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), chlorophyll and soluble sugar(SS)content, biomass accumulation, yield per pot and yield components. Finally, their different biological and physiological drought resistance and response to ABA treatment were compared.[Result]During drought stress, rice maintained higher SOD and CAT activities, leading to a lower MDA content to a certain extent. They synthesized higher soluble sugar content to maintain cell osmotic adjustment. The leaf net Pn decreased consistently. Gs also showed a downward trend with increasing water stress, and Tr consistented with the Gs. Chlorophyll a synthesis was inhibited, and the content decreased. The result showed that dry matter accumulation and yield per pot were decreased significantly compared with CK. Two varieties showed significant differences in response to drought stress, and Zaoyuxiangjing was more drought resistant than Nanjing44. When ABA treated, Pn and dry matter accumulation were reduced in short time. While

  5. Functional Interaction of the SNARE Protein NtSyp121 in Ca2+ Channel Gating,Ca2+ Transients and ABA Signalling of Stomatal Guard Cells

    Institute of Scientific and Technical Information of China (English)

    Sergei Sokolovski; Adrian Hills; Robert A.Gay; Michael R.Blatt

    2008-01-01

    There is now growing evidence that membrane vesicle trafficking proteins,especially of the superfamily of SNAREs,are critical for cellular signalling in plants.Work from this laboratory first demonstrated that a soluble,inhibitory (dominant-negative) fragment of the SNARE NtSyp121 blocked K+ and Cl- channel responses to the stress-related hormone abscisic acid (ABA),but left open a question about functional impacts on signal intermediates,especially on Ca2+-mediated signalling events.Here,we report one mode of action for the SNARE mediated directly through alterations in Caz+ channel gating and its consequent effects on cytosolic-free [Ca2+] ([Ca2+]i) elevation.We find that expressing the same inhibitory fragment of NtSyp121 blocks ABA-evoked stomatal closure,but only partially suppresses stomatal closure in the presence of the NO donor,SNAP,which promotes [Ca2+]i elevation independently of the plasma membrane Ca2+ channels.Consistent with these observations,Ca2+ channel gating at the plasma membrane is altered by the SNARE fragment in a manner effective in reducing the potential for triggering a rise in [Ca2+]i,and we show directly that its expression in vivo leads to a pronounced suppression of evoked [Ca2+]i transients.These observations offer primary evidence for the functional coupling of the SNARE with Ca2+ channels at the plant cell plasma membrane and,because [Ca2+]i plays a key role in the control of K+ and Cl- channel currents in guard cells,they underscore an important mechanism for SNARE integration with ion channel regulation during stomatal closure.

  6. Water stress responses of tomato mutants impaired in hormone biosynthesis reveal abscisic acid, jasmonic acid and salicylic acid interactions

    Directory of Open Access Journals (Sweden)

    Valeria eMuñoz

    2015-11-01

    Full Text Available To investigate the putative crosstalk between JA and ABA in Solanum lycopersicum plants in response to drought, suppressor of prosystemin-mediated responses2 (spr2, JA-deficient and flacca (flc, ABA-deficient mutants together with the naphthalene/salicylate hydroxylase (NahG transgenic (SA-deficient line were used. Hormone profiling and gene expression of key enzymes in ABA, JA and SA biosynthesis were analyzed during early stages of drought. ABA accumulation was comparable in spr2 and wild type (WT plants whereas expression of 9-cis-epoxycarotenoid dioxygenase 1 (NCED1 and NCED2 was different, implying a compensation mechanism between NCED genes and an organ-specific regulation of NCED1 expression. JA levels and 12-oxo-phytodienoic acid reductase 3 (OPR3 expression in flc plants suggest that ABA regulates the induction of the OPR3 gene in roots. By contrast, ABA treatment to flc plants leads to a reduction of JA and SA contents. Furthermore, different pattern of SA accumulation (and expression of isochorismate synthase and phenylalanine ammonia lyase 1 was observed between WT seedlings and mutants, suggesting that SA plays an important role on the early response of tomato plants to drought and also that JA and ABA modulate its biosynthesis. Finally, hormone profiling in spr2 and NahG plants indicate a crosstalk between JA and SA that could enhance tolerance of tomato to water stress.

  7. Water Stress Responses of Tomato Mutants Impaired in Hormone Biosynthesis Reveal Abscisic Acid, Jasmonic Acid and Salicylic Acid Interactions.

    Science.gov (United States)

    Muñoz-Espinoza, Valeria A; López-Climent, María F; Casaretto, José A; Gómez-Cadenas, Aurelio

    2015-01-01

    To investigate the putative crosstalk between JA and ABA in Solanum lycopersicum plants in response to drought, suppressor of prosystemin-mediated responses2 (spr2, JA-deficient) and flacca (flc, ABA-deficient) mutants together with the naphthalene/salicylate hydroxylase (NahG) transgenic (SA-deficient) line were used. Hormone profiling and gene expression of key enzymes in ABA, JA and SA biosynthesis were analyzed during early stages of drought. ABA accumulation was comparable in spr2 and wild type (WT) plants whereas expression of 9-cis-epoxycarotenoid dioxygenase 1 (NCED1) and NCED2 was different, implying a compensation mechanism between NCED genes and an organ-specific regulation of NCED1 expression. JA levels and 12-oxo-phytodienoic acid reductase 3 (OPR3) expression in flc plants suggest that ABA regulates the induction of the OPR3 gene in roots. By contrast, ABA treatment to flc plants leads to a reduction of JA and SA contents. Furthermore, different pattern of SA accumulation (and expression of isochorismate synthase and phenylalanine ammonia lyase 1) was observed between WT seedlings and mutants, suggesting that SA plays an important role on the early response of tomato plants to drought and also that JA and ABA modulate its biosynthesis. Finally, hormone profiling in spr2 and NahG plants indicate a crosstalk between JA and SA that could enhance tolerance of tomato to water stress. PMID:26635826

  8. Arabidopsis HOOKLESS1 Regulates Responses to Pathogens and Abscisic Acid through Interaction with MED18 and Acetylation of WRKY33 and ABI5 Chromatin.

    Science.gov (United States)

    Liao, Chao-Jan; Lai, Zhibing; Lee, Sanghun; Yun, Dae-Jin; Mengiste, Tesfaye

    2016-07-01

    Arabidopsis thaliana HOOKLESS1 (HLS1) encodes a putative histone acetyltransferase with known functions in seedling growth. Here, we show that HLS1 regulates plant responses to pathogens and abscisic acid (ABA) through histone acetylation at chromatin of target loci. The hls1 mutants show impaired responses to bacterial and fungal infection, accelerated senescence, and impaired responses to ABA. HLS1 modulates the expression of WRKY33 and ABA INSENSITIVE5 (ABI5), known regulators of pathogen and ABA responses, respectively, through direct association with these loci. Histone 3 acetylation (H3Ac), a positive mark of transcription, at WRKY33 and ABI5 requires HLS1 function. ABA treatment and pathogen infection enhance HLS1 recruitment and H3Ac at WRKY33. HLS1 associates with Mediator, a eukaryotic transcription coregulatory complex, through direct interaction with mediator subunit 18 (MED18), with which it shares multiple functions. HLS1 recruits MED18 to the WRKY33 promoter, boosting WKRY33 expression, suggesting the synergetic action of HLS1 and MED18. By contrast, MED18 recruitment to ABI5 and transcriptional activation are independent of HLS1. ABA-mediated priming of resistance to fungal infection was abrogated in hls1 and wrky33 mutants but correlated with ABA-induced HLS1 accumulation. In sum, HLS1 provides a regulatory node in pathogen and hormone response pathways through interaction with the Mediator complex and important transcription factors.

  9. Formative Evaluation of an ABA Outreach Training Program for Parents of Children with Autism in Remote Areas

    Science.gov (United States)

    Heitzman-Powell, Linda S.; Buzhardt, Jay; Rusinko, Lisa C.; Miller, Todd M.

    2014-01-01

    Families in rural or remote areas have limited access to evidence-based intervention for their children with autism. Using web-based training and telemedicine technology, the current study investigated the feasibility of training seven parents to implement Applied Behavior Analysis (ABA) strategies with their children with autism. In this…

  10. Bringing ABA into Your Inclusive Classroom: A Guide to Improving Outcomes for Students with Autism Spectrum Disorders

    Science.gov (United States)

    Leach, Debra

    2010-01-01

    Applied behavior analysis (ABA) is a highly effective, rigorously researched intervention for children with autism spectrum disorders--but most teachers don't get the training they need to put it to work in their inclusive classroom. That's why every K-12 educator needs this practical guidebook, packed with teaching plans and plain-English…

  11. Function of the HD-Zip I gene Oshox22 in ABA-mediated drought and salt tolerances in rice

    NARCIS (Netherlands)

    Zhang, S.; Kohlen, W.; Jiang, L.; Bouwmeester, H.J.; Meijer, A.H.; Schluepmann, H.; Liu, C.M.; Ouwerkerk, P.B.F.

    2012-01-01

    Oshox22 belongs to the homeodomain-leucine zipper (HD-Zip) family I of transcription factors, most of which have unknown functions. Here we show that the expression of Oshox22 is strongly induced by salt stress, abscisic acid (ABA), and polyethylene glycol treatment (PEG), and weakly by cold stress.

  12. 40 CFR 63.1295 - Standards for slabstock flexible polyurethane foam production-HAP ABA storage vessels.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Standards for slabstock flexible polyurethane foam production-HAP ABA storage vessels. 63.1295 Section 63.1295 Protection of Environment... Flexible Polyurethane Foam Production § 63.1295 Standards for slabstock flexible polyurethane...

  13. Osmotic stress represses strigolactone biosynthesis in Lotus japonicus roots: exploring the interaction between strigolactones and ABA under abiotic stress

    NARCIS (Netherlands)

    Liu, J.; He, H.; Vitali, M.; Visentin, I.; Charnikhova, T.; Haider, I.; Schubert, A.; Ruyter-Spira, C.P.

    2015-01-01

    Main conclusion Strigolactone changes and cross talk with ABA unveil a picture of root-specific hormonal dynamics under stress. Abstract Strigolactones (SLs) are carotenoid-derived hormones influencing diverse aspects of development and communication with (micro)organisms, and proposed as mediators

  14. Negative regulation of ABA signaling by WRKY33 is critical for Arabidopsis immunity towards Botrytis cinerea 2100.

    Science.gov (United States)

    Liu, Shouan; Kracher, Barbara; Ziegler, Jörg; Birkenbihl, Rainer P; Somssich, Imre E

    2015-06-15

    The Arabidopsis mutant wrky33 is highly susceptible to Botrytis cinerea. We identified >1680 Botrytis-induced WRKY33 binding sites associated with 1576 Arabidopsis genes. Transcriptional profiling defined 318 functional direct target genes at 14 hr post inoculation. Comparative analyses revealed that WRKY33 possesses dual functionality acting either as a repressor or as an activator in a promoter-context dependent manner. We confirmed known WRKY33 targets involved in hormone signaling and phytoalexin biosynthesis, but also uncovered a novel negative role of abscisic acid (ABA) in resistance towards B. cinerea 2100. The ABA biosynthesis genes NCED3 and NCED5 were identified as direct targets required for WRKY33-mediated resistance. Loss-of-WRKY33 function resulted in elevated ABA levels and genetic studies confirmed that WRKY33 acts upstream of NCED3/NCED5 to negatively regulate ABA biosynthesis. This study provides the first detailed view of the genome-wide contribution of a specific plant transcription factor in modulating the transcriptional network associated with plant immunity.

  15. Segmental chain dynamics of ABA triblock copolymer micelles in aqueous solution

    Science.gov (United States)

    Prabhu, Vivek; Wei, Guangmin; Nagao, Michihiro; Venkataraman, Shrinivas; Yang, Yi Yan; Hedrick, James

    The polymer physics of hierarchical, aqueous self-assembled ABA block copolymers is an active area of research for both advanced materials and biomaterial applications. Scattering-based techniques provide a direct measure of the correlations and structure across multiple length and time scales. Hierarchical clusters of micelles are formed by well-defined poly(ethylene glycol) triblock copolymers with oligo-fluorene hydrophobic end-groups in aqueous solutions. The structure and dynamics of this system was studied by small-angle neutron scattering (SANS), and static and dynamic light scattering. We will present new neutron spin-echo spectroscopy (NSE) results that provides direct insight into the segmental chain dynamics constrained by the pi-pi stacking of the oligo-fluorene end groups. The dilute cluster regime within the temperature-composition phase diagram is of current interest. Nist Materials Genome Program.

  16. Modelling of root ABA synthesis, stomatal conductance, transpiration and potato production under water saving irrigation regimes

    DEFF Research Database (Denmark)

    Plauborg, Finn; Abrahamsen, Per; Gjettermann, Birgitte;

    2010-01-01

    . Experimental data was compared to simulated results from the new enhanced Daisy model which include modelling 2D soil water flow, abscisic acid (ABA) signalling and its effect on stomatal conductance and hence on transpiration and assimilation, and finally crop yield. The results demonstrated that the enhanced......Application of water saving irrigation strategies in agriculture has become increasingly important. Both modelling and experimental work are needed to gain more insights into the biological and physical mechanisms in the soil-plant system, which regulates water flow in the system and plays...... a central role in reducing crop transpiration. This paper presented a mechanistic model (Daisy) developed based on data obtained in the SAFIR project on measured leaf gas exchange and soil water dynamics in irrigated potato crops grown in a semi-field environment subjected to different irrigation regimes...

  17. The Prevalence of Substance Use among Bandar Abas Azad Islamic University Students

    Directory of Open Access Journals (Sweden)

    Hamid Mardani

    2012-11-01

    Full Text Available Aim: Substance abuse is one of the most important problem and disease in current century that produced wide worry in the entire world. The solving of addiction among young and educated population is more important issue. The current research was aimed the study of the prevalence rate of the substance use (included: opium, alcohol, cigarette, Hubble bubble among Bandar Abas azad Islamic university students. Method: In this cross sectional study 310 university students were selected by stratified random sampling. For gathering data the prevalence substance use questionnaire was used. Results: The findings showed the start age was 22-25 years old. Also, prevalence rate of cigarette, Hubble bubble, opium, and alcohol were higher in boy students in comparison of girl students. The rate of difference was significant by run of chi square analysis. Conclusion: Sex, the history of substance use in family member, and friends were risk factors of substance use.

  18. Rigidity effect on phase behavior of symmetric ABA triblock copolymers: A Monte Carlo simulation

    Science.gov (United States)

    Song, Jianhui; Shi, Tongfei; Li, Yunqi; Chen, Jizhong; An, Lijia

    2008-08-01

    The phase behavior of symmetric ABA triblock copolymers containing a semiflexible midblock is studied by lattice Monte Carlo simulation. As the midblock evolves from a fully flexible state to a semiflexible state in terms of increase in its persistence length, different phase behaviors are observed while cooling the system from an infinite high temperature to a temperature below TODT (order-disorder transition temperature). Within the midblock flexibility range we studied (lp/Nc51.8%. In order to elucidate phase behavior evolution observed in our simulation, a detailed conformation distribution analysis is also given. Our results bridge a gap of different phase behaviors between rod-coil block copolymer and coil-coil block copolymer and show a necessity to investigate rigidity influence on phase diagram.

  19. AtMyb7, a subgroup 4 R2R3 Myb, negatively regulates ABA-induced inhibition of seed germination by blocking the expression of the bZIP transcription factor ABI5

    KAUST Repository

    Kim, Junhyeok

    2014-08-27

    Various Myb proteins have been shown to play crucial roles in plants, including primary and secondary metabolism, determination of cell fate and identity, regulation of development and involvement in responses to biotic and abiotic stresses. The 126 R2R3 Myb proteins (with two Myb repeats) have been found in Arabidopsis; however, the functions of most of these proteins remain to be fully elucidated. In the present study, we characterized the function of AtMyb7 using molecular biological and genetic analyses. We used qRT-PCR to determine the levels of stress-response gene transcripts in wild-type and atmyb7 plants. We showed that ArabidopsisAtMyb7 plays a critical role in seed germination. Under abscisic acid (ABA) and high-salt stress conditions, atmyb7 plants showed a lower germination rate than did wild-type plants. Furthermore, AtMyb7 promoter:GUS seeds exhibited different expression patterns in response to variations in the seed imbibition period. AtMyb7 negatively controls the expression of the gene encoding bZIP transcription factor, ABI5, which is a key transcription factor in ABA signalling and serves as a crucial regulator of germination inhibition in Arabidopsis. © 2014 John Wiley & Sons Ltd.

  20. The role of the atypical kinases ABC1K7 and ABC1K8 in abscisic acid responses

    Directory of Open Access Journals (Sweden)

    Anna eManara

    2016-03-01

    Full Text Available The ABC1K family of atypical kinases (activity of bc1 complex kinase is represented in bacteria, archaea and eukaryotes. In plants they regulate diverse physiological processes in the chloroplasts and mitochondria, but their precise functions are poorly defined. ABC1K7 and ABC1K8 are probably involved in oxidative stress responses, isoprenyl lipid synthesis and distribution of iron within chloroplasts. Because reactive oxygen species take part in abscisic acid (ABA-mediated processes, we investigated the functions of ABC1K7 and ABC1K8 during germination, stomatal movement and leaf senescence. Both genes were upregulated by ABA treatment and some ABA-responsive physiological processes were affected in abc1k7 and abc1k8 mutants. Germination was more severely affected by ABA, osmotic stress and salt stress in the single and double mutants; the stomatal aperture was smaller in the mutants under standard growth conditions and was not further reduced by exogenous ABA application; ABA-induced senescence symptoms were more severe in the leaves of the single and double mutants compared to wild type leaves. Taken together, our results suggest that ABC1K7 and ABC1K8 might be involved in the cross-talk between ABA and ROS signaling.

  1. Protein tyrosine phosphatases involved in signaling of the ABA-induced H2O2generation in guard cells of Vicia faba L.

    Institute of Scientific and Technical Information of China (English)

    SHI Wuliang; JlA Wensuo; LIU Xin; ZHANG Shuqiu

    2004-01-01

    Although protein tyrosine phosphatases (PTPases) play an important role in signal transduction in animal cells, little is known about the function of PTPases in higher plants. Hydrogen peroxide (H2O2) and mitogen-activated protein kinases (MAPKs) are the critical components of ABA signaling pathway in guard cells. PTPase is an important regulator of MAPK, which is believed to mediate ABA-induced H2O2 generation in guard cells of Viciafaba L. Here, we investigate the possible role of PTPases in stomatal movement process. Phenylarsine oxide (PAO), a specific inhibitor of PTPases, could prevent ABA or H2O2-induced stomatal closure of Vicia faba L; furthermore, it could promote opening of the stomata closed by ABA or H2O2. The activity of PTPases can be effectively inhibited by PAO and H2O2. DTT had no effect on the PAO-induced inhibition of PTPases activity, but it could relieve the inhibition of H2O2 on PTPases activity. PAO could also inhibit the ABA-induced H2O2 generation in guard cells of Vicia faba L. These results suggested that PTPases is a critical signaling component in ABA-induced stomatal closure, and serve as targets for H2O2 lying on the signaling pathways downstream of ABA induced H2O2 generation.

  2. Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture.

    Science.gov (United States)

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

    2008-01-01

    When soil moisture is heterogeneous, sap flow from, and ABA status of, different parts of the root system impact on leaf xylem ABA concentration ([X-ABA]leaf). The robustness of a model for predicting [X-ABA]leaf was assessed. 'Two root-one shoot' grafted sunflower (Helianthus annuus L.) plants received either deficit irrigation (DI, each root system received the same irrigation volumes) or partial rootzone drying (PRD, only one root system was watered and the other dried the soil). Irrespective of whether relative sap flow was assessed using sap flow sensors in vivo or by pressurization of de-topped roots, each root system contributed similarly to total sap flow during DI, while sap flow from roots in drying soil declined linearly with soil water potential (Psisoil) during PRD. Although Psisoil of the irrigated pot determined the threshold Psisoil at which sap flow from roots in drying soil decreased, the slope of this decrease was independent of the wet pot Psisoil. Irrespective of whether sap was collected from the wet or dry root system of PRD plants, or a DI plant, root xylem ABA concentration increased as Psisoil declined. The model, which weighted ABA contributions of each root system according to the sap flow from each, almost perfectly explained [X-ABA] immediately above the graft union. That the model overestimated measured [X-ABA]leaf may result from changes in [X-ABA] along the transport pathway or an artefact of collecting xylem sap from detached leaves. The implications of declining sap flow through partially dry roots during PRD for the control of stomatal behaviour and irrigation scheduling are discussed.

  3. Jasmonic acid interacts with abscisic acid to regulate plant responses to water stress conditions

    OpenAIRE

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

    2015-01-01

    Phytohormones are key players in signaling environmental stress conditions. Hormone profiling together with proline accumulation were studied in leaves and roots of different mutant lines of Arabidopsis. Regulation of proline accumulation in this system seems complex and JA-deficient (jar1-1) and JA-insensitive (jai1) lines accumulating high levels of proline despite their very low ABA levels seems to discard an ABA-dependent response. However, the pattern of proline accumulation in jai1 seed...

  4. Signal Transduction from Water Stress Perception to ABA Accumulation%从水分胁迫的识别到ABA积累的细胞信号转导

    Institute of Scientific and Technical Information of China (English)

    贾文锁; 邢宇; 卢从明; 张建华

    2002-01-01

    由于植物在生长和发育过程中不可避免地要遭受各种环境胁迫的影响,植物只有通过对环境胁迫的快速感知和主动反应才得以生存和发展.植物这种对环境胁迫的快速感知和主动反应体现在环境胁迫下植物可以通过一系列基因的表达调控来实现各种抗逆的生理生化反应.虽然得以鉴定的水分胁迫应答基因越来越多,但其中只有极少的基因在抗逆中的基本功能已得到初步认识.从细胞对水分胁迫原初信号的感知到基因表达调控包括了一系列复杂的细胞逆境信息传递过程.脱落酸(abscisic acid, ABA)作为重要的细胞逆境信号物质介导了一系列基因表达,因此从细胞对水分胁迫原初信号的感知到编码ABA生物合成关键酶基因的表达是一条最为关键的细胞逆境信息传递途径.逆境应答基因功能的鉴定以及对整个细胞信号传递过程中详尽的分子机制的了解无疑是今后最有趣的也是最为重要的研究课题.%To cope with unpredictably environmental perturbations and sometimes stresses, plants have evolved with some mechanisms so that these developing stresses can be sensitively perceived and the physiology can be rapidly regulated. Such perception and regulation can be a kind of feed-forward mechanism and may involve many biochemical and physiological processes and/or the expression of many genes. Although many dehydration-responsive genes have been identified, much fewer of their functions have been known. Such stress-induced responses should include the initial perception of the dehydration signal, then the complicated signal transduction and cellular transmission until to the final gene activation or expression. As an important plant stress hormone abscisic acid (ABA) mediates many such responses. We believe that starting from the initial perception of dehydration to the gene expression leading to the stress-induced ABA biosynthesis is the most important

  5. H2O2 mediates the crosstalk of brassinosteroid and abscisic acid in tomato responses to heat and oxidative stresses

    OpenAIRE

    Zhou, Jie; Wang, Jian; Li, Xin; Xia, Xiao-Jian; Zhou, Yan-Hong; Shi, Kai; Chen, Zhixiang; Yu, Jing-Quan

    2014-01-01

    The production of H2O2 is critical for brassinosteroid (BR)- and abscisic acid (ABA)-induced stress tolerance in plants. In this study, the relationship between BR and ABA in the induction of H2O2 production and their roles in response to heat and paraquat (PQ) oxidative stresses were studied in tomato. Both BR and ABA induced increases in RBOH1 gene expression, NADPH oxidase activity, apoplastic H2O2 accumulation, and heat and PQ stress tolerance in wild-type plants. BR could only induced tr...

  6. Genome-Wide Analysis of MicroRNA Responses to the Phytohormone Abscisic Acid in Populus euphratica.

    Science.gov (United States)

    Duan, Hui; Lu, Xin; Lian, Conglong; An, Yi; Xia, Xinli; Yin, Weilun

    2016-01-01

    MicroRNA (miRNA) is a type of non-coding small RNA with a regulatory function at the posttranscriptional level in plant growth development and in response to abiotic stress. Previous studies have not reported on miRNAs responses to the phytohormone abscisic acid (ABA) at a genome-wide level in Populus euphratica, a model tree for studying abiotic stress responses in woody plants. Here we analyzed the miRNA response to ABA at a genome-wide level in P. euphratica utilizing high-throughput sequencing. To systematically perform a genome-wide analysis of ABA-responsive miRNAs in P. euphratica, nine sRNA libraries derived from three groups (control, treated with ABA for 1 day and treated with ABA for 4 days) were constructed. Each group included three libraries from three individual plantlets as biological replicate. In total, 151 unique mature sequences belonging to 75 conserved miRNA families were identified, and 94 unique sequences were determined to be novel miRNAs, including 56 miRNAs with miRNA(*) sequences. In all, 31 conserved miRNAs and 31 novel miRNAs response to ABA significantly differed among the groups. In addition, 4132 target genes were predicted for the conserved and novel miRNAs. Confirmed by real-time qPCR, expression changes of miRNAs were inversely correlated with the expression profiles of their putative targets. The Populus special or novel miRNA-target interactions were predicted might be involved in some biological process related stress tolerance. Our analysis provides a comprehensive view of how P. euphratica miRNA respond to ABA, and moreover, different temporal dynamics were observed in different ABA-treated libraries. PMID:27582743

  7. Synthesis of ABA Tri-Block Co-Polymer Magnetopolymersomes via Electroporation for Potential Medical Application

    Directory of Open Access Journals (Sweden)

    Jennifer Bain

    2015-12-01

    Full Text Available The ABA tri-block copolymer poly(2-methyloxazoline–poly(dimethylsiloxane–poly(2-methyloxazoline (PMOXA–PDMS–PMOXA is known for its capacity to mimic a bilayer membrane in that it is able to form vesicular polymersome structures. For this reason, it is the subject of extensive research and enables the development of more robust, adaptable and biocompatible alternatives to natural liposomes for biomedical applications. However, the poor solubility of this polymer renders published methods for forming vesicles unreproducible, hindering research and development of these polymersomes. Here we present an adapted, simpler method for the production of PMOXA–PDMS–PMOXA polymersomes of a narrow polydispersity (45 ± 5.8 nm, via slow addition of aqueous solution to a new solvent/polymer mixture. We then magnetically functionalise these polymersomes to form magnetopolymersomes via in situ precipitation of iron-oxide magnetic nanoparticles (MNPs within the PMOXA–PDMS–PMOXA polymersome core and membrane. This is achieved using electroporation to open pores within the membrane and to activate the formation of MNPs. The thick PMOXA–PDMS–PMOXA membrane is well known to be relatively non-permeable when compared to more commonly used di-block polymer membranes due a distinct difference in both size and chemistry and therefore very difficult to penetrate using standard biological methods. This paper presents for the first time the application of electroporation to an ABA tri-block polymersome membrane (PMOXA–PDMS–PMOXA for intravesicular in situ precipitation of uniform MNPs (2.6 ± 0.5 nm. The electroporation process facilitates the transport of MNP reactants across the membrane yielding in situ precipitation of MNPs. Further to differences in length and chemistry, a tri-block polymersome membrane structure differs from a natural lipid or di-block polymer membrane and as such the application and effects of electroporation on this type of

  8. Measurement and modelling of ABA signalling in potato (Solanum tuberosum L.) during partial root-zone drying

    DEFF Research Database (Denmark)

    Liu, Fulai; Song, Ri; Zhang, Xiaoyan;

    2008-01-01

    declined exponentially with declining soil water potential (Psi(soil-dry)); however, after shifting of irrigation, the previously dried roots immediately recovered the full capacity of water uptake. During the first PRD drying cycle, FI plants had the highest stomatal conductance (g(s)), and followed......The objective of this study was to develop a simple mechanistic model to predict the magnitude of ABA signalling ([X-ABA]) of potatoes (Solanum tuberosum L.) exposed to partial root-zone drying (PRD). Potatoes were grown in pots in a glasshouse with the roots split equally between two soil columns....... At tuber initiation stage, plants were subjected to three irrigation treatments: (1) both soil columns were fully irrigated (FI) daily to a volumetric soil water content (theta) of 18.0%; (2) PRD, in which one soil column was irrigated daily to 18.0% while the other was allowed to dry, and the irrigation...

  9. Conformationally constrained opioid ligands: the Dmt-Aba and Dmt-Aia versus Dmt-Tic scaffold.

    Science.gov (United States)

    Ballet, Steven; Feytens, Debby; Wachter, Rien De; Vlaeminck, Magali De; Marczak, Ewa D; Salvadori, Severo; Graaf, Chris de; Rognan, Didier; Negri, Lucia; Lattanzi, Roberta; Lazarus, Lawrence H; Tourwé, Dirk; Balboni, Gianfranco

    2009-01-15

    Replacement of the constrained phenylalanine analogue 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) in the opioid Dmt-Tic-Gly-NH-Bn scaffold by the 4-amino-1,2,4,5-tetrahydro-indolo[2,3-c]azepin-3-one (Aia) and 4-amino-1,2,4,5-tetrahydro-2-benzazepin-3-one (Aba) scaffolds has led to the discovery of novel potent mu-selective agonists (Structures 5 and 12) as well as potent and selective delta-opioid receptor antagonists (Structures 9 and 15). Both stereochemistry and N-terminal N,N-dimethylation proved to be crucial factors for opioid receptor selectivity and functional bioactivity in the investigated small peptidomimetic templates. In addition to the in vitro pharmacological evaluation, automated docking models of Dmt-Tic and Dmt-Aba analogues were constructed in order to rationalize the observed structure-activity data.

  10. Voltage-Dependent Anion Channel 2 of Arabidopsis thaliana (AtVDAC2 Is Involved in ABA-Mediated Early Seedling Development

    Directory of Open Access Journals (Sweden)

    Xufeng Li

    2009-05-01

    Full Text Available The voltage-dependent anion channel (VDAC is the major transport protein in the outer membrane of mitochondria and plays crucial roles in energy metabolism, apoptosis, and metabolites transport. In plants, the expression of VDACs can be affected by different stresses, including drought, salinity and pathogen defense. In this study, we investigated the expression pattern of AtVDAC2 in A. thaliana and found ABA suppressed the accumulation of AtVDAC2 transcripts. Further, phenotype analysis of this VDAC deregulated-expression transgenic Arabidopsis plants indicated that AtVDAC2 anti-sense line showed an ABA-insensitivity phenotype during the early seedling development under ABA treatment. The results suggested that AtVDAC2 might be involved in ABA signaling in A. thaliana.

  11. Plant water stress: Associations between ethylene and abscisic acid response

    Directory of Open Access Journals (Sweden)

    Carolina Salazar

    2015-08-01

    Full Text Available Agriculture is severely impacted by water stress due either to excess (hypoxia/anoxia or deficit of water availability. Hypoxia/anoxia is associated with oxygen (O2 deficiency or depletion, inducing several anatomical, morphological, physiological, and molecular changes. The majority of these alterations are adaptive mechanisms to cope with low O2 availability; among them, alterations in shoot length, aerenchyma formation and adventitious roots have been described in several studies. The aim of this review was to address the association between abscisic acid (ABA and ethylene in function of water availability in plants. The major physiological responses to low O2 are associated with changes in root respiration, stomatal conductance, photosynthesis, and fermentation pathways in roots. In addition, several changes in gene expression have been associated with pathways that are not present under normal O2 supply. The expression of ethylene receptor genes is up-regulated by low O2, and ethylene seems to have a crucial role in anatomical and physiological effects during hypoxia/anoxia. During O2 depletion, ethylene accumulation down-regulates ABA by inhibiting rate-limiting enzymes in ABA biosynthesis and by activating ABA breakdown to phaseic acid. With regard to water deficit, drought is primarily sensed by the roots, inducing a signal cascade to the shoots via xylem causing physiological and morphological changes. Several genes are regulated up or down with osmotic stress; the majority of these responsive genes can be driven by either an ABA-dependent or ABA-independent pathway. Some studies suggest that ethylene shuts down leaf growth very fast after the plant senses limited water availability. Ethylene accumulation can antagonize the control of gas exchange and leaf growth upon drought and ABA accumulation.

  12. Ab initio quasiparticle bandstructure of ABA and ABC-stacked graphene trilayers

    Science.gov (United States)

    Menezes, Marcos; Capaz, Rodrigo; Louie, Steven

    2013-03-01

    We obtain the quasiparticle band structure of ABA and ABC-stacked graphene trilayers through ab initio density functional theory (DFT) and many-body quasiparticle calculations within the GW approximation. To interpret our results, we fit the DFT and GW π bands to a low energy tight-binding model, which is found to reproduce very well the observed features near the K point. The values of the extracted hopping parameters are reported and compared with available theoretical and experimental data. For both stackings, the quasiparticle corrections lead to a renormalization of the Fermi velocity, an effect also observed in previous calculations on monolayer graphene. They also increase the separation between the higher energy bands, which is proportional to the nearest neighbor interlayer hopping parameter γ1. Both features are brought to closer agreement with experiment through the quasiparticle corrections. Finally, other effects, such as trigonal warping, electron-hole assymetry and energy gaps are discussed in terms of the associated parameters. This work was supported by the Brazilian funding agencies: CAPES, CNPq, FAPERJ and INCT-Nanomateriais de Carbono. It was also supported by NSF grant No. DMR10-1006184 and U.S. DOE under Contract No. DE-AC02-05CH11231.

  13. A role for PacMYBA in ABA-regulated anthocyanin biosynthesis in red-colored sweet cherry cv. Hong Deng (Prunus avium L.).

    Science.gov (United States)

    Shen, Xinjie; Zhao, Kai; Liu, Linlin; Zhang, Kaichun; Yuan, Huazhao; Liao, Xiong; Wang, Qi; Guo, Xinwei; Li, Fang; Li, Tianhong

    2014-05-01

    The MYB transcription factors and plant hormone ABA have been suggested to play a role in fruit anthocyanin biosynthesis, but supporting genetic evidence has been lacking in sweet cherry. The present study describes the first functional characterization of an R2R3-MYB transcription factor, PacMYBA, from red-colored sweet cherry cv. Hong Deng (Prunus avium L.). Transient promoter assays demonstrated that PacMYBA physically interacted with several anthocyanin-related basic helix-loop-helix (bHLH) transcription factors to activate the promoters of PacDFR, PacANS and PacUFGT, which are thought to be involved in anthocyanin biosynthesis. Furthermore, the immature seeds of transgenic Arabidopsis plants overexpressing PacMYBA exhibited ectopic pigmentation. Silencing of PacMYBA, using a Tobacco rattle virus (TRV)-induced gene silencing technique, resulted in sweet cherry fruit that lacked red pigment. ABA treatment significantly induced anthocyanin accumulation, while treatment with the ABA biosynthesis inhibitor nordihydroguaiaretic acid (NDGA) blocked anthocyanin production. PacMYBA expression peaked after 2 h of pre-incubation in ABA and was 15.2-fold higher than that of sweet cherries treated with NDGA. The colorless phenotype was also observed in the fruits silenced in PacNCED1, which encodes a key enzyme in the ABA biosynthesis pathway. The endogenous ABA content as well as the transcript levels of six structural genes and PacMYBA in PacNCED1-RNAi (RNA interference) fruit were significantly lower than in the TRV vector control fruit. These results suggest that PacMYBA plays an important role in ABA-regulated anthocyanin biosynthesis and ABA is a signal molecule that promotes red-colored sweet cherry fruit accumulating anthocyanin. PMID:24443499

  14. Effects of exogenous ABA application on post-anthesis dry matter redistribution and grain starch accumulation of winter wheat with different staygreen characteristics

    Institute of Scientific and Technical Information of China (English)

    Dongqing; Yang; Yongli; Luo; Yingli; Ni; Yanping; Yin; Weibing; Yang; Dianliang; Peng; Zhengyong; Cui; Zhenlin; Wang

    2014-01-01

    The objective of this study was to investigate whether and how exogenous abscisic acid(ABA)is involved in mediating starch accumulation in the grain and redistribution of carbohydrates during grain filling of two wheat cultivars with different staygreen characteristics.At blooming stage,plants of Wennong 6(a staygreen cultivar)and Jimai 20(control)were sprayed with10 mg L-1abscisic acid(ABA)for 3 days.The application of ABA significantly(P<0.05)increased grain filling rate,starch accumulation rate and content,remobilization of dry matters to kernels,and 1000-grain weight of the two cultivars.Exogenous ABA markedly(P<0.05)increased grain yield at maturity,and Wennong 6 and Jiami 20 showed 14.14%and 4.86%higher compared yield than the control.Dry matter accumulation after anthesis of Wennong 6 was also significantly(P<0.05)influenced by exogenous ABA,whereas that of Jimai 20 was unchanged.Application of ABA increased endogenous zeatin riboside(ZR)content 7 days after anthesis(DAA),and spraying ABA significantly increased endogenous indole-3-acetic acid(IAA)and ABA contents from 7 to 21 DAA and decreased gibberellin(GA3)content at 14 DAA,but increased GA3content from 21 to 35 DAA.The results suggested that increased yield of staygreen was due to greater starch assimilation owing to a higher filling rate and longer grain-filling duration.

  15. New cross talk between ROS, ABA and auxin controlling seed maturation and germination unraveled in APX6 deficient Arabidopsis seeds.

    Science.gov (United States)

    Chen, Changming; Twito, Shir; Miller, Gad

    2014-01-01

    Successful execution of germination program greatly depends on the seeds' oxidative homeostasis. We recently identified new roles for the H2O2-reducing enzyme ascorbate peroxidase 6 (APX6) in germination control and seeds' stress tolerance. APX6 replaces APX1 as the dominant APX in dry seeds, and its loss-of-function results in reduced germination due to over accumulation of ROS and oxidative damage. Metabolic analyses in dry apx6 seeds, revealed altered homeostasis of primary metabolites including accumulation of TCA cycle metabolites, ABA and auxin, supporting a novel role for APX6 in regulating cellular metabolism. Increased sensitivity of apx6 mutants to ABA or IAA in germination assays indicated impaired perception of these signals. Relative suppression of ABI3 and ABI5 expression, and induction of ABI4, suggested the activation of a signaling route inhibiting germination in apx6 seeds that is independent of ABI3. Here we provide additional evidence linking ABI4 with ABA- and auxin-controlled inhibition of germination and suggest a hypothetical model for the role of APX6 in the regulation of the crosstalk between these hormones and ROS.

  16. ABA Signaling in Guard Cells Entails a Dynamic Protein-Protein Interaction Relay from the PYL-RCAR Family Receptors to Ion Channels

    Institute of Scientific and Technical Information of China (English)

    Sung Chul Lee; Chae Woo Lim; Wenzhi Lan; Kai He; Sheng Luan

    2013-01-01

    Plant hormone abscisic acid (ABA) serves as an integrator of environmental stresses such as drought to trigger stomatal closure by regulating specific ion channels in guard cells.We previously reported that SLACl,an outward anion channel required for stomatal closure,was regulated via reversible protein phosphorylation events involving ABA signaling components,including protein phosphatase 2C members and a SnRK2-type kinase (OST1).In this study,we reconstituted the ABA signaling pathway as a protein-protein interaction relay from the PYL/RCAR-type receptors,to the PP2C-SnRK2 phosphatase-kinase pairs,to the ion channel SLACl.The ABA receptors interacted with and inhibited PP2C phosphatase activity against the SnRK2-type kinase,releasing active SnRK2 kinase to phosphorylate,and activate the SLACl channel,leading to reduced guard cell turgor and stomatal closure.Both yeast two-hybrid and bimolecular fluorescence complementation assays were used to verify the interactions among the components in the pathway.These biochemical assays demonstrated activity modifications of phosphatases and kinases by their interaction partners.The SLACl channel activity was used as an endpoint readout for the strength of the signaling pathway,depending on the presence of different combinations of signaling components.Further study using transgenic plants overexpressing one of the ABA receptors demonstrated that changing the relative level of interacting partners would change ABA sensitivity.

  17. Prediction and Validation of Promoters Involved in the Abscisic Acid Response in Physcomitrella patens

    Institute of Scientific and Technical Information of China (English)

    Gerrit Timmerhaus; Sebastian T.Hanke; Karl Buchta; Stefan A. Rensing

    2011-01-01

    Detection of cis-regulatory elements, such as transcription factor binding sites (TFBS), through utilization of ortholog conservation is possible only if genomic data from closely related organisms are available. An alternative ap-proach is the detection of TFBS based on their overrepresentation in promoters of co-regulated genes. However, this ap-proach usually suffers from a high rate of false-positive prediction. Here, we have conducted a case study using promoters of genes known to be strongly induced by the phytohormone abscisic acid (ABA)in the model plant Physcornitrella patens,a moss. Putative TFBS were detected using three de novo motif detection tools in a strict consensus approach. The resulting motifs were validated using data from microarray expression profiling and were able to predict ABA-induced genes with high specificity (90.48%)at mediocre sensitivity (33.33%). In addition, 27 genes predicted to contain ABA-responsive TFBS were validated using real-time PCR. Here, a total of 37% of the genes could be shown to be induced upon ABA treatment,while 70% were found to be regulated by ABA. We conclude that the consensus approach for motif detection using co-regulation information can be used to identify genes that are regulated under a given stimulus. In terms of evolution, we find that the ABA response has apparently been conserved since the first land plants on the level of families involved in transcriptional regulation.

  18. Foliar abscisic acid-to-ethylene accumulation and response regulate shoot growth sensitivity to mild drought in wheat

    Directory of Open Access Journals (Sweden)

    Ravi eValluru

    2016-04-01

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

  19. Melatonin promotes seed germination under high salinity by regulating antioxidant systems, ABA and GA₄ interaction in cucumber (Cucumis sativus L.).

    Science.gov (United States)

    Zhang, Hai-Jun; Zhang, Na; Yang, Rong-Chao; Wang, Li; Sun, Qian-Qian; Li, Dian-Bo; Cao, Yun-Yun; Weeda, Sarah; Zhao, Bing; Ren, Shuxin; Guo, Yang-Dong

    2014-10-01

    Although previous studies have found that melatonin can promote seed germination, the mechanisms involved in perceiving and signaling melatonin remain poorly understood. In this study, it was found that melatonin was synthesized during cucumber seed germination with a peak in melatonin levels occurring 14 hr into germination. This is indicative of a correlation between melatonin synthesis and seed germination. Meanwhile, seeds pretreated with exogenous melatonin (1 μM) showed enhanced germination rates under 150 mM NaCl stress compared to water-pretreated seeds under salinity stress. There are two apparent mechanisms by which melatonin alleviated salinity-induced inhibition of seed germination. Exogenous melatonin decreased oxidative damage induced by NaCl stress by enhancing gene expression of antioxidants. Under NaCl stress, compared to untreated control, the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were significantly increased by approximately 1.3-5.0-fold, with a concomitant 1.4-2.0-fold increase of CsCu-ZnSOD, CsFe-ZnSOD, CsCAT, and CsPOD in melatonin-pretreated seeds. Melatonin also alleviated salinity stress by affecting abscisic acid (ABA) and gibberellin acid (GA) biosynthesis and catabolism during seed germination. Compared to NaCl treatment, melatonin significantly up-regulated ABA catabolism genes (e.g., CsCYP707A1 and CsCYP707A2, 3.5 and 105-fold higher than NaCl treatment at 16 hr, respectively) and down-regulated ABA biosynthesis genes (e.g., CsNECD2, 0.29-fold of CK2 at 16 hr), resulting in a rapid decrease of ABA content during the early stage of germination. At the same time, melatonin positively up-regulated GA biosynthesis genes (e.g., GA20ox and GA3ox, 2.3 and 3.9-fold higher than NaCl treatment at 0 and 12 hr, respectively), contributing to a significant increase of GA (especially GA4) content. In this study, we provide new evidence suggesting that melatonin alleviates the

  20. Tertiary-amine-containing thermo- and pH-sensitive hydrophilic ABA triblock copolymers: effect of different tertiary amines on thermally induced sol-gel transitions.

    Science.gov (United States)

    Henn, Daniel M; Wright, Roger A E; Woodcock, Jeremiah W; Hu, Bin; Zhao, Bin

    2014-03-11

    This Article reports on the synthesis of a series of well-defined, tertiary-amine-containing ABA triblock copolymers, composed of a poly(ethylene oxide) (PEO) central block and thermo- and pH-sensitive outer blocks, and the study of the effect of different tertiary amines on thermally induced sol-gel transition temperatures (T(sol-gel)) of their 10 wt % aqueous solutions. The doubly responsive ABA triblock copolymers were prepared from a difunctional PEO macroinitiator by atom transfer radical polymerization of methoxydi(ethylene glycol) methacrylate and ethoxydi(ethylene glycol) methacrylate at a feed molar ratio of 30:70 with ∼5 mol % of either N,N-diethylaminoethyl methacrylate (DEAEMA), N,N-diisopropylaminoethyl methacrylate, or N,N-di(n-butyl)aminoethyl methacrylate. The chain lengths of thermosensitive outer blocks and the molar contents of tertiary amines were very similar for all copolymers. Using rheological measurements, we determined the pH dependences of T(sol-gel) of 10 wt % aqueous solutions of these copolymers in a phosphate buffer. The T(sol-gel) versus pH curves of all polymers exhibited a sigmoidal shape. The T(sol-gel) increased with decreasing pH; the changes were small on both high and low pH sides. At a specific pH, the T(sol-gel) decreased with increasing the hydrophobicity of the tertiary amine, and upon decreasing pH the onset pH value for the T(sol-gel) to begin to increase noticeably was lower for the more hydrophobic tertiary amine-containing copolymer. In addition, we studied the effect of different tertiary amines on the release behavior of FITC-dextran from 10 wt % micellar gels in an acidic medium at 37 and 27 °C. The release profiles for three studied hydrogels at 37 °C were essentially the same, suggesting that the release was dominated by the diffusion of FITC-dextran. At 27 °C, the release was significantly faster for the DEAEMA-containing copolymer, indicating that both diffusion and gel dissolution contributed to the

  1. Crucial roles of the pentatricopeptide repeat protein SOAR1 in Arabidopsis response to drought, salt and cold stresses.

    Science.gov (United States)

    Jiang, Shang-Chuan; Mei, Chao; Liang, Shan; Yu, Yong-Tao; Lu, Kai; Wu, Zhen; Wang, Xiao-Fang; Zhang, Da-Peng

    2015-07-01

    Whereas several mitochondrial/chloroplast pentatricopeptide repeat (PPR) proteins have been reported to regulate plant responses to abiotic stresses, no nucleus-localized PPR protein has been found to play role in these processes. In the present experiment, we provide evidence that a cytosol-nucleus dual-localized PPR protein SOAR1, functioning to negatively regulate abscisic acid (ABA) signaling in seed germination and postgermination growth, is a crucial, positive regulator of plant response to abiotic stresses. Downregulation of SOAR1 expression reduces, but upregulation of SOAR1 expression enhances, ABA sensitivity in ABA-induced promotion of stomatal closure and inhibition of stomatal opening, and plant tolerance to multiple, major abiotic stresses including drought, high salinity and low temperature. Interestingly and importantly, the SOAR1-overexpression lines display strong abilities to tolerate drought, salt and cold stresses, with surprisingly high resistance to salt stress in germination and postgermination growth of seeds that are able to potentially germinate in seawater, while no negative effect on plant growth and development was observed. So, the SOAR1 gene is likely useful for improvement of crops by transgenic manipulation to enhance crop productivity in stressful conditions. Further experimental data suggest that SOAR1 likely regulates plant stress responses at least partly by integrating ABA-dependent and independent signaling pathways, which is different from the ABI2/ABI1 type 2C protein phosphatase-mediated ABA signaling. These findings help to understand highly complicated stress and ABA signalling network. PMID:26093896

  2. Cloning of new members of heat shock protein HSP101 gene family in wheat (Triticum aestivum (L.) Moench) inducible by heat, dehydration, and ABA(1).

    Science.gov (United States)

    Campbell, J L; Klueva, N Y; Zheng, H G; Nieto-Sotelo, J; Ho, T D; Nguyen, H T

    2001-01-26

    We have cloned two cDNAs, TaHSP101B and TaHSP101C, encoding two heat stress-inducible members of HSP101/ClpB family in bread wheat (Triticum aestivum (L.) Moench.). Proteins encoded by these cDNAs are highly similar at the primary sequence level and diverged from the previously reported TaHSP101 (designated TaHSP101A) both in the consensus ATP/GTP-binding region II and in the carboxy terminal region. The HSP101 gene was determined to be a single copy gene or a member of a small gene family in hexaploid wheat. Messages encoding HSP101 proteins were inducible by heat stress treatments in both wheat leaves and roots. Accumulation of the TaHSP101C mRNA was less abundant than that of TaHSP101B mRNA. We are showing for the first time that in addition to heat stress, expression of HSP101 mRNAs in wheat leaves was induced by a 2-h dehydration and a treatment with 5x10(-5)M ABA, but not affected by chilling or wounding, indicating that HSP101 proteins may be involved in both heat and drought responses in wheat. PMID:11342108

  3. Involvement of ABA- and H2O2-dependent cytosolic glucose-6-phosphate dehydrogenase in maintaining redox homeostasis in soybean roots under drought stress.

    Science.gov (United States)

    Wang, Huahua; Yang, Lidan; Li, Yan; Hou, Junjie; Huang, Junjun; Liang, Weihong

    2016-10-01

    The roles of abscisic acid (ABA) and hydrogen peroxide (H2O2) in inducing glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49) activity and the possible roles of G6PDH in regulating ascorbate-glutathione (AsA-GSH) cycle were investigated in soybean (Glycine max L.) roots under drought stress. Drought caused a marked increase of the total and cytosolic G6PDH activities and triggered a rapid ABA and H2O2 accumulation in soybean roots. Exogenous ABA or H2O2 treatment elevated the total and cytosolic G6PDH activities, whereas suppressing ABA or H2O2 production inhibited the drought-induced increase in total and cytosolic G6PDH activities, suggesting that ABA and H2O2 are required for drought-induced increase of total G6PDH activity, namely cytosolic G6PDH activity. Furthermore, ABA induced H2O2 production by stimulating NADPH oxidase activity under drought stress. Moreover, drought significantly increased the contents of AsA and GSH and the activities of key enzymes in AsA-GSH cycle, while application of G6PDH inhibitor to seedlings significantly reduced the above effect induced by drought. Taken together, these results indicate that H2O2 acting as a downstream signaling molecule of ABA mediates drought-induced increase in cytosolic G6PDH activity, and that enhanced cytosolic G6PDH activity maintains cellular redox homeostasis by regulating AsA-GSH cycle in soybean roots. PMID:27285781

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

    Science.gov (United States)

    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

  5. The structure of arabidopsis thaliana OST1 provides insights into the kinase regulation mechanism in response to osmotic stress

    KAUST Repository

    Yunta, Cristina

    2011-11-01

    SnRK [SNF1 (sucrose non-fermenting-1)-related protein kinase] 2.6 [open stomata 1 (OST1)] is well characterized at molecular and physiological levels to control stomata closure in response to water-deficit stress. OST1 is a member of a family of 10 protein kinases from Arabidopsis thaliana (SnRK2) that integrates abscisic acid (ABA)-dependent and ABA-independent signals to coordinate the cell response to osmotic stress. A subgroup of protein phosphatases type 2C binds OST1 and keeps the kinase dephosphorylated and inactive. Activation of OST1 relies on the ABA-dependent inhibition of the protein phosphatases type 2C and the subsequent self-phosphorylation of the kinase. The OST1 ABA-independent activation depends on a short sequence motif that is conserved among all the members of the SnRK2 family. However, little is known about the molecular mechanism underlying this regulation. The crystallographic structure of OST1 shows that ABA-independent regulation motif stabilizes the conformation of the kinase catalytically essential α C helix, and it provides the basis of the ABA-independent regulation mechanism for the SnRK2 family of protein kinases. © 2011 Elsevier Ltd. All rights reserved.

  6. Physiological and molecular responses to drought in Petunia: the importance of stress severity

    OpenAIRE

    Kim, Jongyun; Malladi, Anish; van Iersel, Marc W.

    2012-01-01

    Plant responses to drought stress vary depending on the severity of stress and the stage of drought progression. To improve the understanding of such responses, the leaf physiology, abscisic acid (ABA) concentration, and expression of genes associated with ABA metabolism and signalling were investigated in Petunia × hybrida. Plants were exposed to different specific substrate water contents (θ = 0.10, 0.20, 0.30, or 0.40 m3·m–3) to induce varying levels of drought stress. Plant responses were...

  7. Knockout of AtDjB1, a J-domain protein from Arabidopsis thaliana, alters plant responses to osmotic stress and abscisic acid.

    Science.gov (United States)

    Wang, Xingxing; Jia, Ning; Zhao, Chunlan; Fang, Yulu; Lv, Tingting; Zhou, Wei; Sun, Yongzhen; Li, Bing

    2014-10-01

    AtDjB1 is a member of the Arabidopsis thaliana J-protein family. AtDjB1 is targeted to the mitochondria and plays a crucial role in A. thaliana heat and oxidative stress resistance. Herein, the role of AtDjB1 in adapting to saline and drought stress was studied in A. thaliana. AtDjB1 expression was induced through salinity, dehydration and abscisic acid (ABA) in young seedlings. Reverse genetic analyses indicate that AtDjB1 is a negative regulator in plant osmotic stress tolerance. Further, AtDjB1 knockout mutant plants (atj1-1) exhibited greater ABA sensitivity compared with the wild-type (WT) plants and the mutant lines with a rescued AtDjB1 gene. AtDjB1 gene knockout also altered the expression of several ABA-responsive genes, which suggests that AtDjB1 is involved in osmotic stress tolerance through its effects on ABA signaling pathways. Moreover, atj1-1 plants exhibited higher glucose levels and greater glucose sensitivity in the post-germination development stage. Applying glucose promoted an ABA response in seedlings, and the promotion was more evident in atj1-1 than WT seedlings. Taken together, higher glucose levels in atj1-1 plants are likely responsible for the greater ABA sensitivity and increased osmotic stress tolerance. PMID:24521401

  8. Sequence variation and expression analysis of seed dormancy- and germination-associated ABA- and GA-related genes in rice cultivars

    Directory of Open Access Journals (Sweden)

    Fei eLiu

    2011-06-01

    Full Text Available Abscisic acid (ABA and Gibberellic acid (GA play key roles in regulating seed dormancy and germination. First, when examining germination of different rice cultivars, we found that their germination timing and dormancy status are rather distinct, coupled with different GA/ABA ratio. Second, we studied genomic sequences of ABA and GA dormancy- and germination-associated genes in rice and discovered single nucleotide polymorphisms (SNPs and insertions/deletions (Indels in both coding and regulatory sequences. We aligned all these variations to the genome assemblies of 9311 and PA64s and demonstrated their relevance to seed dormancy both quantitatively and qualitatively based on gene expression data. Third, we surveyed and compared differentially-expressed genes in dry seeds between 9311 and PA64s to show that these differentially-expressed genes may play roles in seed dormancy and germination.

  9. Stomatal closure of Pelargonium × hortorum in response to soil water deficit is associated with decreased leaf water potential only under rapid soil drying.

    Science.gov (United States)

    Boyle, Richard K A; McAinsh, Martin; Dodd, Ian C

    2016-01-01

    Soil water deficits applied at different rates and for different durations can decrease both stomatal conductance (gs ) and leaf water potential (Ψleaf ). Understanding the physiological mechanisms regulating these responses is important in sustainable irrigation scheduling. Glasshouse-grown, containerized Pelargonium × hortorum BullsEye plants were irrigated either daily at various fractions of plant evapotranspiration (100, 75 and 50% ET) for 20 days or irrigation was withheld for 4 days. Xylem sap was collected and gs and Ψleaf were measured on days 15 and 20, and on days 16-19 for the respective treatments. Xylem sap pH and NO3 (-) and Ca(2+) concentrations did not differ between irrigation treatments. Xylem abscisic acid (ABA) concentrations ([ABA]xyl ) increased within 24 h of irrigation being withheld whilst gs and Ψleaf decreased. Supplying irrigation at a fraction of daily ET produced a similar relationship between [ABA]xyl and gs , but did not change Ψleaf . Treatment differences occurred independently of whether Ψleaf was measured in whole leaves with a pressure chamber, or in the lamina with a thermocouple psychrometer. Plants that were irrigated daily showed lower [ABA]xyl than plants from which irrigation was withheld, even at comparable soil moisture content. This implies that regular re-watering attenuates ABA signaling due to maintenance of soil moisture in the upper soil levels. Crucially, detached leaves supplied with synthetic ABA showed a similar relationship between [ABA]xyl and gs as intact plants, suggesting that stomatal closure of P. hortorum in response to soil water deficit is primarily an ABA-induced response, independent of changes in Ψleaf . PMID:25974219

  10. Quality of the paratransit service (tricycle and its operation in Aba, Nigeria: An analysis of customers' opinions

    Directory of Open Access Journals (Sweden)

    Obioma R. Nwaogbe

    2012-11-01

    Full Text Available This study examines the quality of the paratransit service and its operations in Aba, Abia State, Nigeria, with a view to identifying its challenges and contributions to informal transport and equitable service distribution to the residents of Aba. Structured questionnaires and past literature were used as sources of data. The primary data included road networks, number of trips per day by operators, operating speed, and purpose of travel, passengers' security, tricycle speed, and waiting time. The study was conducted by using two questionnaires: one for the operators and the other for tricycle users. The total number of completed questionnaires for the survey was 100 for operators and 229 for users. The sampling technique used was random sampling from several zones of the study area. Data were analysed using percentage and Chi-square statistical techniques for testing the hypotheses with the Minitab 11.0 version package. The study found that 92% of operators reported a high level of road network deterioration, and 61% reported making 9-12 trips per day. The hypothesis test was used to study people's feelings about the attributes of the service provided for paratransit users, such as affordability, regularity, comfort and safety. It was found that there is no significant difference at the 5% level between the various categories of these respondents.

  11. 脱落酸和热激处理对棉花苗期生长的影响%Effect of Heat-shock and ABA Application on Cotton Seedlings

    Institute of Scientific and Technical Information of China (English)

    陈于陇; 宋学贞; 杨国正

    2012-01-01

    In growth chamber, cotton (Gossypium hirsutum L.)seedling responses to Heat-shock (42℃,2h) on germination seeds, ABA (10-5 mol/L) soaking of seeds (6h), irrigating roots (5 mL/pot) and spraying on leaf(5 mL/pot) at 2-leaf stage were studied under controlled high temperature (35 ℃) and water deficit (drying) conditions. The responses were judged by the growth rate of cotton seedlings. The results showed that under the normal growth condition, comparing to the control, stress pre-treatments inhibited the growth of cotton seedlings, especially inhibited the growth of seedling height and stem diameter. However, during the high-temperature and drought period, stress pre-treatment hindered the increase of seedling height again, but stimulated the growth of biomass. It was suggested that stress pre-treatment would be beneficial for the seedlings to get resistance in a certain degree to later stress.%采用人工气候箱研究了棉花(Gossypium hirsutum L.)种子热激萌动(42 ℃)2 h、ABA( 10-5 mol/L)浸种6h、二叶期用ABA叶面喷施和根部灌施对棉苗抵御高温干旱逆境能力的影响.结果表明,与对照相比,各处理对棉苗生长具有一定的抑制作用,其中对苗高和茎粗的抑制作用较大;但在遭遇高温干旱条件时,各处理苗高增长速度较慢,但生物质量增加速度较快.说明一定程度的逆境锻炼有助于棉苗获得一定抵御逆境的能力.

  12. Hybrid micellar hydrogels of a thermosensitive ABA triblock copolymer and hairy nanoparticles: effect of spatial location of hairy nanoparticles on gel properties.

    Science.gov (United States)

    Hu, Bin; Henn, Daniel M; Wright, Roger A E; Zhao, Bin

    2014-09-23

    This article reports a method for control of spatial location of nanoparticles (NPs) in hybrid micellar hydrogels of a thermosensitive ABA triblock copolymer and polymer brush-grafted NPs (hairy NPs), either inside or outside the core of micelles, and the study of the effect of different locations of NPs on gel properties. Two batches of thermosensitive polymer brush-grafted, 17 nm silica NPs with different lower critical solution temperatures (LCSTs) and a thermosensitive ABA triblock copolymer composed of a poly(ethylene oxide) central block and thermosensitive outer blocks (ABA-D) were synthesized. The different locations of NPs were achieved by controlling the LCST of hairy NPs (LCST(NP)) relative to that of the thermosensitive outer blocks of ABA-D (LCST(ABA)). When the LCST(NP) and LCST(ABA) were similar, the NPs resided in the core of micelles upon heating from below the LCST(NP) and LCST(ABA). When the LCST(NP) was significantly higher, the NPs were located outside the core of micelles as confirmed by fluorescent resonance energy transfer. The effects of different locations of hairy NPs and NP-to-polymer mass ratio on properties of hybrid micellar hydrogels formed from aqueous solutions of ABA-D with a concentration of 10 wt % and various amounts of hairy NPs were studied by rheological measurements. The sol-gel transition temperature (T(sol-gel)) and dynamic storage modulus G' of the gels with NPs inside the core of micelles did not change much with increasing the NP-to-polymer mass ratio. In contrast, the T(sol-gel) of gels with NPs in the interstitial space among micelles increased slightly and the G' decreased significantly with the increase of the NP-to-polymer ratio. The hairy NPs in the interstitial space appeared to affect the formation of polymer networks and increase the fraction of polymer loops, resulting in a lower density of bridging chains and thus a lower G'. In addition, for gels with NPs in the interstitial space, a noticeable increase in

  13. Deficiência hídrica e aplicação de ABA nas trocas gasosas e no acúmulo de flavonoides em calêndula (Calendula officinalis L. = Water deficit and ABA application on leaf gas exchange and flavonoid content in marigold (Calendula officinalis L..

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Pacheco

    2011-04-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da deficiencia hidrica e aplicacao de acido abscisico (ABA sobre aspectos fisiologicos e teor de flavonoides em plantas de calendula. Oexperimento foi instalado em condicoes de casa-de-vegetacao com plantas envasadas. No inicio do florescimento de plantas de calendula, foram aplicados quatro intervalos de suspensao da irrigacao (irrigacao diaria; tres; seis e nove dias sem irrigar, acompanhados por tres doses de ABA (0, 10 e 100 ƒÊM. Avaliou-se o conteudo relativo de agua na folha (CRA e as trocas gasosas, utilizando-se um analisador portatil por infravermelho (A: fotossintese liquida, gs: condutancia estomatica, E: transpiracao, Ci: concentracao intercelular de CO2 e EUA: eficiencia de uso daagua. Aos nove dias sem irrigacao ocorreram reducoes significativas em todas as variaveis de trocas gasosas analisadas, independente da aplicacao de ABA. Concluiu-se que o efeito principal do ABA foi o de causar diminuicao na gs, a qual foi acompanhada de reducao em A somente quando as plantas estavam desidratadas. As intensidades de deficiencia hidrica testadas nao causaram interferencia no acumulo de flavonoides nas inflorescencias. Entretanto, o ABA restringiu a biossintese de flavonoides, tanto nas plantas-controle como nas plantas submetidas a deficiencia hidrica.The goal of this study was to evaluate the effects of water deficit and abscisic acid (ABA application on physiological parameters and flavonoid production in marigold plant. The experiment was performed under nursery conditions with potted plants. It was tested water deficit by withholding water (control . diary irrigation, 3, 6 and9 days without irrigation followed by 3 ABA concentrations (0, 10 e 100 ƒÊM applied in the beginning of blooming. It was evaluated the relative water content and the leaf gas exchange using a portable infrared gas analyzer (A: net photosynthesis, gs: stomatal conductance, E: transpiration, Ci: CO2 intercellular

  14. Cloning and expression of lipoxygenase genes and enzyme activity in ripening persimmon fruit in response to GA and ABA treatment

    Science.gov (United States)

    Two genes of the lipoxygenase (LOX) family, DkLox1 and DkLox3 (GenBank accession No. JF436951 and JF436950), were cloned from persimmon fruit (Diospyros kaki L. ‘Fuping Jianshi’). Sequence analysis indicated that they belong to the 9-LOX sub-group. Heterologous expression of DkLox1 in E. coli produc...

  15. 生物源脱落酸(ABA)提高茄苗抗旱能力的效果及机理%Effect of Natural ABA on Increasing Drought Resistance and Its Mechanism in Eggplant Seedling

    Institute of Scientific and Technical Information of China (English)

    汤日圣; 唐现洪; 钟雨; 张大栋; 余永柱; 童红玉

    2006-01-01

    以茄子苏琦1号为材料,探讨了生物源脱落酸(ABA)提高茄苗抗旱性的作用.结果表明:ABA能有效减缓干旱胁迫条件下茄苗叶片相对含水量的下降,提高茄苗的抗旱性;在干旱胁迫过程中,经ABA处理的茄苗叶片中超氧物歧化酶(SOD)活性的降低幅度和丙二醛(MDA)的积累明显低于对照,脯氨酸、抗坏血酸(AsA)、还原型谷胱甘肽(GSH)和可溶性糖含量都明显高于对照.

  16. Disease resistance or growth: the role of plant hormones in balancing immune responses and fitness costs

    NARCIS (Netherlands)

    Denance, N.; Sanchez Vallet, A.; Goffner, D.; Molina, A.

    2013-01-01

    Plant growth and response to environmental cues are largely governed by phytohormones. The plant hormones ethylene, jasmonic acid, and salicylic acid (SA) play a central role in the regulation of plant immune responses. In addition, other plant hormones, such as auxins, abscisic acid (ABA), cytokini

  17. RBSDV 侵染对水稻 ABA 代谢相关基因表达的影响%Effect of RBSDV Infection on Transcriptional Expression of Abscisic Acid Metabolism Related Genes in Rice

    Institute of Scientific and Technical Information of China (English)

    倪海平; 徐秋芳; 兰莹; 陈晴晴; 张金凤; 周益军

    2015-01-01

    为明确水稻黑条矮缩病毒(Rice black streaked dwarf virus ,RBSDV)侵染对水稻脱落酸(abscisic acid,ABA)含量的影响,通过灰飞虱在水稻日本晴和淮稻5号两个品种上人工接种 RBSDV,待接种的水稻表现明显矮缩症状时,采用 ELISA方法测定 ABA 含量.结果显示,在接种 RBSDV 的日本晴和淮稻5号中,ABA 含量均明显增加.接种病毒的日本晴植株中ABA 含量为111.04 ng/g,而对照中仅为60.86 ng/g;淮稻5号对照植物 ABA 含量为70.61 ng/g,而病株中 ABA 的含量为102.60 ng/g.为进一步明确病毒侵染如何调控 ABA 的含量,采用荧光定量 PCR 方法分析了日本晴接种 RBSDV 8 d,12 d,16 d 和60 d 时 ABA 合成关键基因(OsZEP 、OsNCED1、OsNCED2、OsNCED3、OsNCED4和 OsNCED5)及分解关键基因(OsABA8ox1、OsABA8ox2和 OsABA8ox3)mRNA 相对表达量的变化.结果显示,病毒侵染8 d,ABA 合成和分解代谢基因的表达量均高于对照,其中 OsNCED4和 OsNCED5的表达量随病毒侵染时间的延长而增加,至60 d 时 OsNCED3、OsNCED4和 OsNCED5的表达量为对照的3.97、7.66和2.99倍,而 OsZEP ,OsABA8ox1和 OsABA8ox2的表达量则随侵染时间的延长而降低.RBSDV 侵染后可能既影响了 ABA 合成也影响了其分解,两者共同作用导致了 ABA 含量增加.%To investigate the effect of virus infection on abscisic acid (ABA)content in rice,two rice varieties, Nipponbare and Huaidao 5 ,were inoculated with rice black streaked dwarf virus (RBSDV)artificially via small brown planthoppers,and the ABA content was measured by ELISA method when the plants showed the obvious viral disease symptoms.The results showed that the ABA content was increased in virus infected rice.The ABA content in virus infected Nipponbare was 1 1 1 .04 ng/g compared to 60.86 ng/g in the control.In Huaidao 5 ,it was 102.60 ng/g in the virus infected plants and 70.6 1 ng/g in the control.To reveal how the virus regulates the ABA content,the relative

  18. Characterization of a Poly(styrene-block-methylacrylate-random-octadecylacrylate-block-styrene) Shape Memory ABA Triblock Copolymer

    Science.gov (United States)

    Fei, Pengzhan; Cavicchi, Kevin

    2011-03-01

    A new ABA triblock copolymer of poly(styrene-block- methylacrylate-random-octadecylacrylate-block-styrene) (PS-b- PMA-r-PODA-b-PS) was synthesized by reversible addition fragmentation chain transfer polymerization. The triblock copolymer can generate a three-dimensional, physically crosslinked network by self-assembly, where the glassy PS domains physically crosslink the midblock chains. The side chain crystallization of the polyoctadecylacrylare (PODA) side chain generates a second reversible network enabling shape memory properties. Shape memory tests by uniaxial deformation and recovery of molded dog-bone shape samples demonstrate that shape fixities above 96% and shape recoveries above 98% were obtained for extensional strains up to 300%. An outstanding advantage of this shape memory material is that it can be very easily shaped and remolded by elevating the temperature to 140circ; C, and after remolding the initial shape memory properties are totally recovered by eliminating the defects introduced by the previous deformation cycling.

  19. CHOICE AND PATTERN OF THERAPEUTIC ANTIMICROBIALS IN COMPANION ANIMALS (DOGS, CATS AND BIRDS IN ABA, ABIA STATE

    Directory of Open Access Journals (Sweden)

    P.O. NWIYI

    2014-03-01

    Full Text Available The choice and pattern of therapeutic antimicrobials were evaluated in companion animals. This was carried out by visiting the clinics and verifying the records of the pharmacy unit of the ten veterinary clinics and poultry services located within Aba, Abia State. Simple random sampling was used in selecting the clinics for this study. For the purpose of this study, a bird was used to represent a poultry farm. A total of 1961 companion animals made up of 1468 dogs, 172 cats and 321 birds (poultry farms. This study arises due to the need to avoid possibility of build-up of multi-drug resistance as a result of excessive drug usage and to know the choice antimicrobial currently in use. From the study, the choice antimicrobials use for dogs was Amoxicillin, for cat was Duxipra while Enrofloxacin was for birds, the percentage usage was represented as 45%, 50% and 40% in that order.

  20. ABA and bluegrass drought resistance%脱落酸与早熟禾的耐旱性

    Institute of Scientific and Technical Information of China (English)

    柳小妮

    2002-01-01

    在田间试验的26个早熟禾材料中,筛选出了各方面表现良好的7个种(品种),在室内土壤干旱胁迫下测试其叶内脱落酸(ABA)含量(高效液相色谱法:HPLC)及相对含水量(Rwc)的变化,并分析其耐旱性的强弱.结果表明早熟禾各品种耐旱性强弱依次为:天祝华藏寺野生草地早熟禾、大穗早熟禾、扁杆早熟禾、硬质早熟禾、宁夏华灰早熟禾、瓦巴斯草地早熟禾、思托佩草地早熟禾.

  1. Proteomic analyses reveal the key roles of BrlA and AbaA in biogenesis of gliotoxin in Aspergillus fumigatus

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Kwang-Soo, E-mail: shinks@dju.kr [Division of Life Science, Daejeon University, Daejeon, 300-716 (Korea, Republic of); Kim, Young Hwan [Biomedical Omics Team, Korea Basic Science Institute (KBSI), Ohcang, 368-883 (Korea, Republic of); Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 305-764 (Korea, Republic of); Department of Bio-Analytical Science, University of Science and Technology, Daejeon, 305-333 (Korea, Republic of); Yu, Jae-Hyuk, E-mail: jyu1@wisc.edu [Departments of Bacteriology and Genetics, The University of Wisconsin–Madison, Madison, WI, 53706 (United States)

    2015-07-31

    The opportunistic human pathogenic fungus Aspergillus fumigatus primarily reproduces by forming a large number of asexual spores (conidia). Sequential activation of the central regulators BrlA, AbaA and WetA is necessary for the fungus to undergo asexual development. In this study, to address the presumed roles of these key developmental regulators during proliferation of the fungus, we analyzed and compared the proteomes of vegetative cells of wild type (WT) and individual mutant strains. Approximately 1300 protein spots were detectable from 2-D electrophoresis gels. Among these, 13 proteins exhibiting significantly altered accumulation levels were further identified by ESI-MS/MS. Markedly, we found that the GliM and GliT proteins associated with gliotoxin (GT) biosynthesis and self-protection of the fungus from GT were significantly down-regulated in the ΔabaA and ΔbrlA mutants. Moreover, mRNA levels of other GT biosynthetic genes including gliM, gliP, gliT, and gliZ were significantly reduced in both mutant strains, and no and low levels of GT were detectable in the ΔbrlA and ΔabaA mutant strains, respectively. As GliT is required for the protection of the fungus from GT, growth of the ΔbrlA mutant with reduced levels of GliT was severely impaired by exogenous GT. Our studies demonstrate that AbaA and BrlA positively regulate expression of the GT biosynthetic gene cluster in actively growing vegetative cells, and likely bridge morphological and chemical development during the life-cycle of A. fumigatus. - Highlights: • Proteome analyses of WT and mutants reveal 13 differentially expressed proteins. • The GliT and GliM proteins are significantly down-regulated by ΔabaA and ΔbrlA. • Expression of other gliotoxin biosynthetic genes is lowered by ΔabaA and ΔbrlA. • Growth of ΔbrlA strain lacking GliT is completely inhibited by exogenous gliotoxin. • BrlA and AbaA play key roles in biogenesis of gliotoxin in Aspergillus fumigatus.

  2. Pollution of shallow groundwater in urban areas of developing countries; a comparative case study of Enugu and Aba towns of southeastern Nigeria

    International Nuclear Information System (INIS)

    Field studies involving hydrochemical sampling of the groundwater in dug wells and shallow boreholes were carried out in the towns of Enugu (underlain by laterized clay aquifers) and Aba (underlain by loose sandstones). The results suggested generally similar enrichment pattern of some sewage sensitive geochemical parameters (Cl-, NO3, electric conductivity, HCO-3 and p H). There is, for instance, a clear elevation of the concentration of nitrates and chlorides above background values of zero and 10 mg/l respectively and these could be correlated with the intensity of urbanization in both towns. A significant observation was the relatively higher concentration of the sensitive parameters in the laterized clay aquifer beneath Enugu with respect to the sandy aquifer beneath Aba. The median concentration values of nitrates and chlorides were 20 mg/l and 16 mg/l at Aba whereas the values at Enugu were 27 mg/l and 72 mg/I respectively. The average electric conductance at Aba (300 mS/cm) was only about 50% of the corresponding value at Enugu, (610 mS/cm). There was also a more uniform concentration range at Enugu whereas outlier values were more common at Aba. The explanation for this could be found in both the matrix lithology and aquifer hydraulics in the areas. It is projected from the findings that thin laterized clay aquifers in hilly terrains could provide a highly conducive environment for rapid contaminant distribution. Such a hydrogeologic environment may even pose greater danger than that of a permeable sandy aquifer in flat terrains

  3. Responsibilities

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    ONE day in 1993, a woman named Xing Jun came to the Organization Department of Tianjin’s Municipal Party Committee. She approached the door to the director’s office, opened it, and walked straight into the responsibility for training, examining, recommending and appointing cadres at all levels of the municipal government. Because the office has so much influence over the fate of many cadres, the director’s position commands much respect and awe. However, people see no

  4. Intertrial intervals and contextual conditioning in appetitive pavlovian learning: effects over the ABA renewal paradigm.

    Science.gov (United States)

    Carranza-Jasso, Rodrigo; Urcelay, Gonzalo P; Nieto, Javier; Sánchez-Carrasco, Livia

    2014-09-01

    Three experiments using rats in an appetitive conditioning procedure analyzed the effect of short and long (50s vs. 1440s) intertrial intervals (ITI) over the acquisition of conditioned stimulus (CS), context (Ctxt), and unconditioned stimulus (US) associations, as well as the effect on the extinction and renewal of the conditioned response to the CS. Experiment 1 revealed more contextual conditioned responses in groups trained with the short ITIs, however the renewal effect was not observed during test phase with either ITI condition. When subjects were pre-exposed to the contexts before the acquisition phase (Experiment 2) renewal of the conditioned response (CR) was only observed in long ITI group. However, when the acquisition context was extinguished (Experiment 3) the renewal effect observed in the Experiment 2 was weakened. In all three experiments subjects showed a similar number of responses to the tone predicting food, however they showed a clear contextual conditioning effect only for the groups trained with short ITIs. It is noteworthy that the acquisition context showed high levels of the CR in the renewal test only for groups trained with short ITIs (Experiment 2) but these responses were absent if additional contextual extinction was imposed before such test (Experiment 3). In general, all groups showed similar acquisition curves for the CS but only Short groups had an increase in the CR during the pre-CS. Also, context conditioning does not interfere with the conditioning of the CS and context pre-exposure prior to acquisition is essential in order to observe the renewal effect when long ITIs are used.

  5. New 2',6'-dimethyl-L-tyrosine (Dmt) opioid peptidomimetics based on the Aba-Gly scaffold. Development of unique mu-opioid receptor ligands.

    Science.gov (United States)

    Ballet, Steven; Salvadori, Severo; Trapella, Claudio; Bryant, Sharon D; Jinsmaa, Yunden; Lazarus, Lawrence H; Negri, Lucia; Giannini, Elisa; Lattanzi, Roberta; Tourwé, Dirk; Balboni, Gianfranco

    2006-06-29

    The Aba-Gly scaffold, incorporated into Dmt-Tic ligands (H-Dmt-Tic-Gly-NH-CH2-Ph, H-Dmt-Tic-Gly-NH-Ph, H-Dmt-Tic-NH-CH2-Bid), exhibited mixed micro/delta or delta opioid receptor activities with micro agonism. Substitution of Tic by Aba-Gly coupled to -NH-CH2-Ph (1), -NH-Ph (2), or -Bid (Bid=1H-benzimidazole-2-yl) (3) shifted affinity (Ki(micro)=0.46, 1.48, and 19.9 nM, respectively), selectivity, and bioactivity to micro-opioid receptors. These compounds represent templates for a new class of lead opioid agonists that are easily synthesized and suitable for therapeutic pain relief.

  6. Expression of ABA synthesis and metabolism genes under different irrigation strategies and atmospheric VPDs is associated with stomatal conductance in grapevine (Vitis vinifera L. cv Cabernet Sauvignon)

    OpenAIRE

    Speirs, Jim; Binney, Allan; Collins, Marisa; Edwards, Everard; Loveys, Brian

    2013-01-01

    The influence of different levels of irrigation and of variation in atmospheric vapour pressure deficit (VPD) on the synthesis, metabolism, and transport of abscisic acid (ABA) and the effects on stomatal conductance were examined in field-grown Cabernet Sauvignon grapevines. Xylem sap, leaf tissue, and root tissue were collected at regular intervals during two seasons in conjunction with measurements of leaf water potential (Ψleaf) and stomatal conductance (gs). The different irrigation leve...

  7. Vliv ABA na tvorbu sušiny a obsah energie kukuřice seté při vodním stresu

    OpenAIRE

    Jiřička, Petr

    2012-01-01

    The aim of this thesis was to determine differences in the rate of photosynthetic energy storage in different parts of the body and plant dry matter production of selected varieties of corn grown in drought conditions and the influence of ABA applications at various stages of drought effects. The experiment included four varieties of maize: Ambrosini, Lars, LG 3252 and Ricardinio. Plants were grown in a greenhouse of the Department of Botany and Plant Physiology Life Sciences in Prague. Th...

  8. Vliv ABA na výměnu plynů kukuřice seté při vodním stresu

    OpenAIRE

    Andrle, Michal

    2012-01-01

    The objective of this diploma work is monitoring the rate of photosynthesis and transpiration of maize plants exposed for 18 days and plant water stress, which was applied ABA, and their comparison with regular irrigated plants. Although corn is a plant belonging to the C4 photosynthetic cycle, and yet to the lack of water is very sensitive and every year due to this stressor to significant loss of income. Indispensable role not only in periods of drought phytohormones play, which are nat...

  9. Sequentially Different AB Diblock and ABA Triblock Copolymers as P3HT:PCBM Interfacial Compatibilizers for Bulk-Heterojunction Photovoltaics.

    Science.gov (United States)

    Fujita, Hiroyuki; Michinobu, Tsuyoshi; Fukuta, Seijiro; Koganezawa, Tomoyuki; Higashihara, Tomoya

    2016-03-01

    The P3HT:PCBM (P3HT = poly(3-hexylthiophene, PCBM = phenyl-C61-butyric acid methyl ester) bulk-heterojunction (BHJ) organic photovoltaic (OPV) cells using the AB diblock and ABA triblock copolymers (A = polystyrene derivative with donor-acceptor units (PTCNE) and B = P3HT) as compatibilizers were fabricated. Under the optimized blend ratio of the block copolymer, the power conversion efficiency (PCE) was enhanced. This PCE enhancement was clearly related to the increased short-circuit current (J(sc)) and fill factor (FF). The incident photon to current efficiency (IPCE) measurement suggested that the P3HT crystallinity was improved upon addition of the block copolymers. The increased P3HT crystallinity was consistent with the increased photovoltaic parameters, such as J(sc), FF, and consequently the PCE. The surface energies of these block copolymers suggested their thermodynamically stable location at the interface of P3HT:PCBM, showing the efficient compatibilizing performance, resulting in enlarging and fixing the interfacial area and suppressing the recombination of the generated carriers. Grazing incidence X-ray scattering (GIXS) results confirmed the superior compatibilizing performance of the ABA triblock copolymer when compared to the AB diblock copolymer by the fact that, after blending the ABA triblock copolymer in the P3HT:PCBM system, the enhanced crystallinity of matrix P3HT was observed in the excluded areas of the less-aggregated PCBM domains, changing the P3HT crystalline domain orientation from "edge-on" to "isotropic". This is, to the best of our knowledge, the first sequential effect (AB vs ABA) of the block copolymers on the compatibilizing performances based on BHJ OPV device systems.

  10. Sequentially Different AB Diblock and ABA Triblock Copolymers as P3HT:PCBM Interfacial Compatibilizers for Bulk-Heterojunction Photovoltaics.

    Science.gov (United States)

    Fujita, Hiroyuki; Michinobu, Tsuyoshi; Fukuta, Seijiro; Koganezawa, Tomoyuki; Higashihara, Tomoya

    2016-03-01

    The P3HT:PCBM (P3HT = poly(3-hexylthiophene, PCBM = phenyl-C61-butyric acid methyl ester) bulk-heterojunction (BHJ) organic photovoltaic (OPV) cells using the AB diblock and ABA triblock copolymers (A = polystyrene derivative with donor-acceptor units (PTCNE) and B = P3HT) as compatibilizers were fabricated. Under the optimized blend ratio of the block copolymer, the power conversion efficiency (PCE) was enhanced. This PCE enhancement was clearly related to the increased short-circuit current (J(sc)) and fill factor (FF). The incident photon to current efficiency (IPCE) measurement suggested that the P3HT crystallinity was improved upon addition of the block copolymers. The increased P3HT crystallinity was consistent with the increased photovoltaic parameters, such as J(sc), FF, and consequently the PCE. The surface energies of these block copolymers suggested their thermodynamically stable location at the interface of P3HT:PCBM, showing the efficient compatibilizing performance, resulting in enlarging and fixing the interfacial area and suppressing the recombination of the generated carriers. Grazing incidence X-ray scattering (GIXS) results confirmed the superior compatibilizing performance of the ABA triblock copolymer when compared to the AB diblock copolymer by the fact that, after blending the ABA triblock copolymer in the P3HT:PCBM system, the enhanced crystallinity of matrix P3HT was observed in the excluded areas of the less-aggregated PCBM domains, changing the P3HT crystalline domain orientation from "edge-on" to "isotropic". This is, to the best of our knowledge, the first sequential effect (AB vs ABA) of the block copolymers on the compatibilizing performances based on BHJ OPV device systems. PMID:26864393

  11. Urban women’s use of rural-based health care services: The case of Igbo women in Aba city, Nigeria

    OpenAIRE

    Izugbara, C. Otutubikey; Afangideh, A. Isong

    2005-01-01

    This study addresses the quest for rural-based health care services among women in urban Nigeria relying on a large qualitative database obtained from 63 Igbo women living in Aba, Nigeria. Results indicate that urban Igbo women of different socioeconomic and demographic characteristics utilize the services of different rural-based health care providers—indigenous healers, traditional birth attendants (TBAs), faith/spiritual, western-trained doctors and nurses as well as chemist shopkeepers—fo...

  12. Organochlorine pesticide residues in surface water from Sichuan Basin to Aba Prefecture profile, east of the Tibetan Plateau

    Science.gov (United States)

    Liu, Hongxia; Hu, Ying; Qi, Shihua; Xing, Xinli; Zhang, Yuan; Yang, Dan; Qu, Chengkai

    2015-06-01

    Organochlorine pesticides (OCPs) found in rivers from the Sichuan Basin to Aba Prefecture profile were analyzed to assess possible health risks to adults and children who use the river as a source of drinking water. OCP concentrations in surface water ranged between 22.29-274.28 ng·L-1. Compared with other published data around the world, OCP levels in this study were moderate. Among all OCPs, hexachlorobenzene (HCB) and hexachlorocyclohexanes (HCHs) were the predominant compounds. Higher concentrations of OCPs were attributed close to the agricultural fields of the Sichuan Basin, current OCPs inputs, and long-range atmospheric transport from abroad. Various spatial patterns of OCPs in the profile might be affected by the usage and physicochemical properties of the pesticides, in addition to the adjacent geographical environment. The health risk assessment indicated that most OCPs had little impact on human health according to the acceptable risk level for carcinogens (10-6) recommended by the US EPA. However, carcinogenic effects caused by heptachlor, Aldrin, HCB, and α-HCH might occur in drinking water. The risk of negative impacts caused by OCPs is much higher for children than for adults.

  13. ABA TRIBLOCK COPOLYMERS WITH PENDANT HYDROXYL GROUPS PREPARED BY CONTROLLED CATIONIC POLYMERIZATION AND THEIR USE AS DELIVERY CARRIER FOR PACLITAXEL

    Institute of Scientific and Technical Information of China (English)

    Ping Ren; Yi-bo Wu; Wen-li Guo; Shu-xin Li; Ying Chen

    2013-01-01

    To improve the hydrophilicity of poly(styrene-b-isobutylene-b-styrene) (SIBS),this study focuses on the synthesis of novel functional ABA triblock copolymer thermoplastic elastomers (TPEs) with polyisobutylene (PIB) as rubbery segments.The precursor poly{(styrene-co-4-[2-(tert-butyldimethylsiloxy) ethyl]styrene)-b-isobutylene-b-(styrene-co-4-[2-(tert-butyldimethylsiloxy)ethyl]styrene)}(P(St-co-TBDMES)-PIB-P(St-co-TBDMES)) triblock copolymer was first synthesized by living sequential cationic copolymerization of isobutylene (IB) with styrene (St) and 4-[2-(tert-butyldimethylsiloxy)ethyl]styrene (TBDMES) using 1,4-di(2-chloro-2-propyl)benzene (DiCumC1)/titanium tetrachloride (TiCl4)/2,6-di-tert-butylpyridine (DtBP) as the initiating system.Then,P(St-co-TBDMES)-PIB-P(St-co-TBDMES) was hydrolyzed in the presence of tetra-butylammonium fluoride to yield poly{[styrene-co-4-(2-hydroxyethyl)styrene]-b-isobutylene-b-[styrene-co-4-(2-hydroxyethyl)styrene]} (P(St-co-HOES)-PIB-P(St-co-HOES)) with pendant hydroxyl groups.P(St-co-HOES)-PIB-P(St-co-HOES) used as the paclitaxel carrier was also investigated in this study.Comparing with SIBS,P(St-co-HOES)-PIB-P(St-co-HOES) has exhibited better compatibility with paclitaxel and higher release rate.

  14. Involvement of CmWRKY10 in Drought Tolerance of Chrysanthemum through the ABA-Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Muhammad Abuzar Jaffar

    2016-05-01

    Full Text Available Drought is one of the important abiotic factors that adversely affects plant growth and production. The WRKY transcription factor plays a pivotal role in plant growth and development, as well as in the elevation of many abiotic stresses. Among three major groups of the WRKY family, the group IIe WRKY has been the least studied in floral crops. Here, we report functional aspects of group IIe WRKY member, i.e., CmWRKY10 in chrysanthemum involved in drought tolerance. The transactivation assay showed that CmWRKY10 had transcriptional activity in yeast cells and subcellular localization demonstrated that it was localized in nucleus. Our previous study showed that CmWRKY10 could be induced by drought in chrysanthemum. Moreover, the overexpression of CmWRKY10 in transgenic chrysanthemum plants improved tolerance to drought stress compared to wild-type (WT. High expression of DREB1A, DREB2A, CuZnSOD, NCED3A, and NCED3B transcripts in overexpressed plants provided strong evidence that drought tolerance mechanism was associated with abscisic acid (ABA pathway. In addition, lower accumulation of reactive oxygen species (ROS and higher enzymatic activity of peroxidase, superoxide dismutase and catalase in CmWRKY10 overexpressed lines than that of WT demonstrates its role in drought tolerance. Together, these findings reveal that CmWRKY10 works as a positive regulator in drought stress by regulating stress-related genes.

  15. Involvement of CmWRKY10 in Drought Tolerance of Chrysanthemum through the ABA-Signaling Pathway.

    Science.gov (United States)

    Jaffar, Muhammad Abuzar; Song, Aiping; Faheem, Muhammad; Chen, Sumei; Jiang, Jiafu; Liu, Chen; Fan, Qingqing; Chen, Fadi

    2016-01-01

    Drought is one of the important abiotic factors that adversely affects plant growth and production. The WRKY transcription factor plays a pivotal role in plant growth and development, as well as in the elevation of many abiotic stresses. Among three major groups of the WRKY family, the group IIe WRKY has been the least studied in floral crops. Here, we report functional aspects of group IIe WRKY member, i.e., CmWRKY10 in chrysanthemum involved in drought tolerance. The transactivation assay showed that CmWRKY10 had transcriptional activity in yeast cells and subcellular localization demonstrated that it was localized in nucleus. Our previous study showed that CmWRKY10 could be induced by drought in chrysanthemum. Moreover, the overexpression of CmWRKY10 in transgenic chrysanthemum plants improved tolerance to drought stress compared to wild-type (WT). High expression of DREB1A, DREB2A, CuZnSOD, NCED3A, and NCED3B transcripts in overexpressed plants provided strong evidence that drought tolerance mechanism was associated with abscisic acid (ABA) pathway. In addition, lower accumulation of reactive oxygen species (ROS) and higher enzymatic activity of peroxidase, superoxide dismutase and catalase in CmWRKY10 overexpressed lines than that of WT demonstrates its role in drought tolerance. Together, these findings reveal that CmWRKY10 works as a positive regulator in drought stress by regulating stress-related genes. PMID:27187353

  16. Integrating role of ethylene and ABA in tomato plants adaptation to salt stress

    DEFF Research Database (Denmark)

    Amjad, Muhammad; Akhtar, Javaid; Anwar-ul-Haq, Muhammad;

    2014-01-01

    Saline stress seriously disrupts the growth and physiology of plants, whereas phytohormones play an important role in regulating plant responses to salinity stress. The involvement of phytohormones in salt tolerance of tomato and the interaction between potassium and phytohormones was studied...... the negative impact of salinity stress and thus increased the hormone concentration. Enhanced concentration of hormones in salt-tolerant genotype positively affected plant physiology and thus better chlorophyll content index (CCI), stomatal conductance and ion homeostasis that is higher K+/Na+ ratio...... in the xylem. Salt stress altered the stomatal morphology and significantly decreased stomatal density and aperture in both genotypes. It was concluded that under salt stress enhanced phytohormones concentration positively affected the tomato plant physiology, especially in the salt-tolerant genotype...

  17. A role for intestinal TLR4-driven inflammatory response during activity-based anorexia

    Science.gov (United States)

    Belmonte, Liliana; Achamrah, Najate; Nobis, Séverine; Guérin, Charlène; Riou, Gaëtan; Bôle-Feysot, Christine; Boyer, Olivier; Richard, Vincent; Rego, Jean Claude Do; Déchelotte, Pierre; Goichon, Alexis; Coëffier, Moïse

    2016-01-01

    Anorexia nervosa (AN) is associated with low-grade systemic inflammation and altered gut microbiota. However, the molecular origin of the inflammation remains unknown. Toll-like receptors are key regulators of innate immune response and their activation seems also to be involved in the control of food intake. We used activity-based anorexia (ABA) model to investigate the role of TLR4 and its contribution in anorexia-associated low-grade inflammation. Here, we found that ABA affected early the intestinal inflammatory status and the hypothalamic response. Indeed, TLR4 was upregulated both on colonic epithelial cells and intestinal macrophages, leading to elevated downstream mucosal cytokine production. These mucosal changes occurred earlier than hypothalamic changes driving to increased levels of IL-1β and IL-1R1 as well as increased levels of plasma corticosterone. Paradoxically, TLR4-deficient mice exhibited greater vulnerability to ABA with increased mortality rate, suggesting a major contribution of TLR4-mediated responses during ABA-induced weight loss. PMID:27779218

  18. Expression Analysis of MYC Genes from Tamarix hispida in Response to Different Abiotic Stresses

    Directory of Open Access Journals (Sweden)

    Guifeng Liu

    2012-01-01

    Full Text Available The MYC genes are a group of transcription factors containing both bHLH and ZIP motifs that play important roles in the regulation of abscisic acid (ABA-responsive genes. In the present study, to investigate the roles of MYC genes under NaCl, osmotic and ABA stress conditions, nine MYC genes were cloned from Tamarix hispida. Real-time reverse-transcriptase (RT-PCR showed that all nine MYC genes were expressed in root, stem and leaf tissues, but that the levels of the transcripts of these genes in the various tissues differed notably. The MYC genes were highly induced in the roots in response to ABA, NaCl and osmotic stresses after 3 h; however, in the stem and leaf tissues, MYC genes were highly induced only when exposed to these stresses for 6 h. In addition, most of these MYC genes were highly expressed in roots in comparison with stems and leaves. Furthermore, the MYC genes were more highly induced in roots than in stem and leaf tissues, indicating that these genes may play roles in stress responses mainly in the roots rather than the stems and leaves. The results of this present study suggest that MYCs are involved in salt and osmotic stress tolerances and are controlled by the ABA signal transduction pathway.

  19. The role of the HvNAC6 transcription factor in response to biotic and abiotic stress in barley

    DEFF Research Database (Denmark)

    Chen, Yan-Jun

    -mediated transformation methods could be used to study stress responses at the whole-plant level. The abscisic acid (ABA) and salicylic acid (SA) levels were measured during Bgh infection to investigate the involvement of these hormones and TF in the basal resistance. HvNAC6 RNAi plants were also subjected to dehydration...

  20. Plant natriuretic peptides are apoplastic and paracrine stress response molecules

    KAUST Repository

    Wang, Yuhua

    2011-04-07

    Higher plants contain biologically active proteins that are recognized by antibodies against human atrial natriuretic peptide (ANP). We identified and isolated two Arabidopsis thaliana immunoreactive plant natriuretic peptide (PNP)-encoding genes, AtPNP-A and AtPNP-B, which are distantly related members of the expansin superfamily and have a role in the regulation of homeostasis in abiotic and biotic stresses, and have shown that AtPNP-A modulates the effects of ABA on stomata. Arabidopsis PNP (PNP-A) is mainly expressed in leaf mesophyll cells, and in protoplast assays we demonstrate that it is secreted using AtPNP-A:green fluorescent protein (GFP) reporter constructs and flow cytometry. Transient reporter assays provide evidence that AtPNP-A expression is enhanced by heat, osmotica and salt, and that AtPNP-A itself can enhance its own expression, thereby generating a response signature diagnostic for paracrine action and potentially also autocrine effects. Expression of native AtPNP-A is enhanced by osmotica and transiently by salt. Although AtPNP-A expression is induced by salt and osmotica, ABA does not significantly modulate AtPNP-A levels nor does recombinant AtPNP-A affect reporter expression of the ABA-responsive RD29A gene. Together, these results provide experimental evidence that AtPNP-A is stress responsive, secreted into the apoplastic space and can enhance its own expression. Furthermore, our findings support the idea that AtPNP-A, together with ABA, is an important component in complex plant stress responses and that, much like in animals, peptide signaling molecules can create diverse and modular signals essential for growth, development and defense under rapidly changing environmental conditions. © 2011 The Author.

  1. Fruit load induces changes in global gene expression and in abscisic acid (ABA) and indole acetic acid (IAA) homeostasis in citrus buds.

    Science.gov (United States)

    Shalom, Liron; Samuels, Sivan; Zur, Naftali; Shlizerman, Lyudmila; Doron-Faigenboim, Adi; Blumwald, Eduardo; Sadka, Avi

    2014-07-01

    Many fruit trees undergo cycles of heavy fruit load (ON-Crop) in one year, followed by low fruit load (OFF-Crop) the following year, a phenomenon known as alternate bearing (AB). The mechanism by which fruit load affects flowering induction during the following year (return bloom) is still unclear. Although not proven, it is commonly accepted that the fruit or an organ which senses fruit presence generates an inhibitory signal that moves into the bud and inhibits apical meristem transition. Indeed, fruit removal from ON-Crop trees (de-fruiting) induces return bloom. Identification of regulatory or metabolic processes modified in the bud in association with altered fruit load might shed light on the nature of the AB signalling process. The bud transcriptome of de-fruited citrus trees was compared with those of ON- and OFF-Crop trees. Fruit removal resulted in relatively rapid changes in global gene expression, including induction of photosynthetic genes and proteins. Altered regulatory mechanisms included abscisic acid (ABA) metabolism and auxin polar transport. Genes of ABA biosynthesis were induced; however, hormone analyses showed that the ABA level was reduced in OFF-Crop buds and in buds shortly following fruit removal. Additionally, genes associated with Ca(2+)-dependent auxin polar transport were remarkably induced in buds of OFF-Crop and de-fruited trees. Hormone analyses showed that auxin levels were reduced in these buds as compared with ON-Crop buds. In view of the auxin transport autoinhibition theory, the possibility that auxin distribution plays a role in determining bud fate is discussed.

  2. AtPUB 19, a U-Box E3 Ubiquitin Ligase, Negatively Regulates Abscisic Acid and Drought Responses in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Yong-Chang Liu; Yao-Rong Wu; Xia-He Huang; Jie Sun; Qi Xie

    2011-01-01

    Ubiquitination is an important protein post-translational modification,which is involved in various cellular processes in higher plants,and U-box E3 ligases play important roles in diverse functions in eukaryotes.Here,we describe the functions of Arabidopsis thaliana PUB19 (AtPUB19),which we demonstrated in an in vitro assay to encode a U-box type E3 ubiquitin ligase.AtPUB19 was up-regulated by drought,salt,cold,and abscisic acid (ABA).Down-regulation of AtPUB19led to hypersensitivity to ABA,enhanced ABA-induced stomatal closing,and enhanced drought tolerance,while AtPUB 19overexpression resulted in the reverse phenotypes.Molecular analysis showed that the expression levels of a number of ABA and stress marker genes were altered in both AtPUB 19 overexpressing and atpub 19-1 mutant plants.In summary,our data show that AtPUB19 negatively regulates ABA and drought responses in A.thaliana.

  3. Estudos etnobotanicos em comunidades continentais da area de proteção ambiental de Guaraqueçaba Parana - Brasil

    OpenAIRE

    Lima, Roberto Xavier de

    2013-01-01

    Este trabalho tem por objetivo resgatar o conhecimento etnobotânico em dez comunidades continentais da Área de Proteção Ambiental (APA) de Guaraqueçaba. A APA está localizada no litoral norte do Estado do Paraná - Brasil, é uma Unidade de Conservação composta por ecossistemas da Floresta Ombrófila Densa (Floresta Atlântica) em bom estado de conservação, compreendendo 313.400 ha. Populações Tradicionais, com elevado conhecimento da flora regional, estão distribuídas em 57 localidades. Foram s...

  4. ABA and GA3 increase carbon allocation in different organs of grapevine plants by inducing accumulation of non-structural carbohydrates in leaves, enhancement of phloem area and expression of sugar transporters.

    Science.gov (United States)

    Murcia, Germán; Pontin, Mariela; Reinoso, Herminda; Baraldi, Rita; Bertazza, Gianpaolo; Gómez-Talquenca, Sebastián; Bottini, Rubén; Piccoli, Patricia N

    2016-03-01

    Grape quality for winemaking depends on sugar accumulation and metabolism in berries. Abscisic acid (ABA) and gibberellins (GAs) have been reported to control sugar allocation in economically important crops, although the mechanisms involved are still unknown. The present study tested if ABA and gibberellin A3 (GA3) enhance carbon allocation in fruits of grapevines by modifying phloem loading, phloem area and expression of sugar transporters in leaves and berries. Pot-grown Vitis vinifera cv. Malbec plants were sprayed with ABA and GA3 solutions. The amount of soluble sugars in leaves and berries related to photosynthesis were examined at three points of berry growth: pre-veraison, full veraison and post-veraison. Starch levels and amylase activity in leaves, gene expression of sugar transporters in leaves and berries and phloem anatomy were examined at full veraison. Accumulation of glucose and fructose in berries was hastened in ABA-treated plants at the stage of full veraison, which was correlated with enhancement of Vitis vinifera HEXOSE TRANSPORTER 2 (VvHT2) and Vitis vinifera HEXOSE TRANSPORTER 6 (VvHT6) gene expression, increases of phloem area and sucrose content in leaves. On the other hand, GA3 increased the quantity of photoassimilates delivered to the stem thus increasing xylem growth. In conclusion, stimulation of sugar transport by ABA and GA3 to berries and stems, respectively, was due to build-up of non-structural carbohydrates in leaves, modifications in phloem tissue and modulation in gene expression of sugar transporters.

  5. ABA-Mediated Inhibition of Germination Is Related to the Inhibition of Genes Encoding Cell-Wall Biosynthetic and Architecture:Modifying Enzymes and Structural Proteins in Medicago truncatula Embryo Axis

    Institute of Scientific and Technical Information of China (English)

    Christine Gimeno-Gilles; Eric Lelièvre; Laure Viau; Mustafa Malik-Ghulam; Claudie Ricoult; Andreas Niebel; Nathalie Leduc; Anis M. Limami

    2009-01-01

    Radicle emergence and reserves mobilization are two distinct programmes that are thought to control germination. Both programs are influenced by abscissic acid (ABA) but how this hormone controls seed germination is still poorly known. Phenotypic and microscopic observations of the embryo axis of Medicago truncatula during germination in mitotic inhibition condition triggered by 10 μM oryzalin showed that cell division was not required to allow radicle emergence. A suppressive subtractive hybridization showed that more than 10% of up-regulated genes in the embryo axis encoded proteins related to cell-wall biosynthesis. The expression of α-expansins, pectin-esterase, xylogucan-endotransglycosidase, cellulose synthase, and extensins was monitored in the embryo axis of seeds germinated on water, constant and transitory ABA. These genes were overexpressed before completion of germination in the control and strongly inhibited by ABA. The expression was re-established in the ABA transitory-treatment after the seeds were transferred back on water and proceeded to germination. This proves these genes as contributors to the completion of germination and strengthen the idea that cell-wall loosening and remodeling in relation to cell expansion in the embryo axis is a determinant feature in germination. Our results also showed that ABA controls germination through the control of radicle emergence, namely by inhibiting cell-wall loosening and expansion.

  6. Immunolocalization and Quantitation of ABA and IAA in the Organs of Wheat (TriticumaestivumL.) Under Drought Stress%干旱胁迫下小麦(Triticumaestivum L.)幼苗中ABA和IAA的免疫定位及定量分析

    Institute of Scientific and Technical Information of China (English)

    张炜; 高巍; 曹振; 何丽珊; 谭桂玉; 王保民

    2014-01-01

    ABA含量差异均呈极显著(P<0.01)。用icELISA对IAA进行检测,正常供水时,小麦幼苗根、叶鞘、叶片中的IAA含量分别为72.81、274.46和195.75 ng·g-1 FW。水分胁迫条件下, IAA含量增加但幅度不大,分别为123.56、400.48和417.30 ng·g-1 FW。叶片中IAA上升的幅度稍大为对照的2.13倍,根、叶鞘中的IAA含量分别为对照的1.70和1.46倍。显著性分析(t检验法)显示,在干旱胁迫与正常供水条件下小麦幼苗根中IAA含量差异不显著(P>0.05),但叶片和叶鞘中IAA含量差异极显著(P<0.01)。水分胁迫下小麦幼苗根、叶鞘、叶片中ABA和IAA含量均增加,ABA含量增加幅度较大,IAA较ABA含量增加幅度较小。二者之间协调的总趋势是向着气孔关闭,促进根系生长,减缓茎叶生长速率的方向发展,可有效的避免缺水伤害。%Objective Drought, a serious problem existed in agricultural production, is one of the most important factors limiting agricultural growth and further expanding the crops acreage. Study of the mechanism of plant drought resistance will provide an important safeguard for the increase of agricultural production and incomes. Phytohormone plays a significant role in plant resistance to water deficiency. Based on this study we may further understand the function of phytohormone in plants in response to drought stress, and provide a theoretical basis for the regulation of plant hormone in the production and cultivation of crop in arid regions.[Method]With wheat variety Lumai No.21 as material, immunohistochemical localization was used to investigate the distribution of endogenous hormones ABA and IAA in wheat organs(root, leaf sheath and leaf blade)under drought-stress. While an indirect competitive enzyme-linked immunosorbent assay (icELISA) was applied to quantitate the content changes of ABA and IAA in wheat organs. The chemical signal intensity of the immunohistochemical

  7. [The ABC of abscisic acid action in plant drought stress responses].

    Science.gov (United States)

    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

  8. Disease resistance or growth: the role of plant hormones in balancing immune responses and fitness costs

    OpenAIRE

    Denancé, Nicolas; Sánchez-Vallet, Andrea; Goffner, Deborah; Molina, Antonio

    2013-01-01

    Plant growth and response to environmental cues are largely governed by phytohormones. The plant hormones ethylene, jasmonic acid, and salicylic acid (SA) play a central role in the regulation of plant immune responses. In addition, other plant hormones, such as auxins, abscisic acid (ABA), cytokinins, gibberellins, and brassinosteroids, that have been thoroughly described to regulate plant development and growth, have recently emerged as key regulators of plant immunity. Plant hormones inter...

  9. Disease resistance or growth: the role of plant hormones in balancing immune responses and fitness costs

    OpenAIRE

    Nicolas eDenancé; Andrea eSánchez-Vallet; Deborah eGoffner; Antonio eMolina

    2013-01-01

    Plant growth and response to environmental cues are largely governed by phytohormones. The plant hormones ethylene, jasmonic acid and salicylic acid (SA) play a central role in the regulation of plant immune responses. In addition, other plant hormones, such as auxins, abscisic acid (ABA), cytokinins, gibberellins and brassinosteroids, that have been thoroughly described to regulate plant development and growth, have recently emerged as key regulators of plant immunity. Plant hormones interac...

  10. 绿豆不同抗旱性品种叶片脱落酸含量的比较研究%Comparison of Content of ABA in Leaves of Varieties of Mung Bean with Different Drought Resistance

    Institute of Scientific and Technical Information of China (English)

    郝建军; 尹智超; 秦萍; 于洋; 梁杰; 尹凤祥

    2013-01-01

    选用绿豆品种白绿9号(BL9)、白绿11号(BL11)、大鹦哥绿935(BL935)、大鹦哥绿985(BL985)为试材,在苗期、花期、成熟期测定绿豆不同抗旱性品种叶片脱落酸(abscisic acid,ABA)的含量,研究3个生长发育时期,绿豆不同抗旱性品种叶片ABA含量的变化情况,并初步分析ABA的动态分布与绿豆抗旱性的关系.试验结果证明,从苗期、开花期到成熟期,各品种叶片内ABA含量的动态变化呈逐渐升高的趋势,并且抗旱性较强的绿豆品种叶片ABA含量相对较低.特别是抗旱性不同的绿豆品种在开花期的叶片ABA含量差异达到极显著水平.%In this study,changes of ABA content in leaves of four species of the mung bean (BL9,BL11,BL935,BL985) in seedling,blossom and maturation were determined by the ELISA method.The relationship between dynamic distribution of ABA and resistance to drought was analyzed.The results showed that ABA content of leaves of all mung bean varieties increased gradually from seedling,blossom to maturation.ABA content in mung bean leaves was lower in the drought-resistant varieties.The differences of ABA content in mung bean leaves at blossom were significant among varieties with different resistance to drought.

  11. Ecophysiological response to seasonal variations in water availability in the arborescent, endemic plant Vellozia gigantea.

    Science.gov (United States)

    Morales, Melanie; Garcia, Queila S; Munné-Bosch, Sergi

    2015-03-01

    The physiological response of plants growing in their natural habitat is strongly determined by seasonal variations in environmental conditions and the interaction of abiotic and biotic stresses. Here, leaf water and nutrient contents, changes in cellular redox state and endogenous levels of stress-related phytohormones (abscisic acid (ABA), salicylic acid and jasmonates) were examined during the rainy and dry season in Vellozia gigantea, an endemic species growing at high elevations in the rupestrian fields of the Espinhaço Range in Brazil. Enhanced stomatal closure and increased ABA levels during the dry season were associated with an efficient control of leaf water content. Moreover, reductions in 12-oxo-phytodienoic acid (OPDA) levels during the dry season were observed, while levels of other jasmonates, such as jasmonic acid and jasmonoyl-isoleucine, were not affected. Changes in ABA and OPDA levels correlated with endogenous concentrations of iron and silicon, hydrogen peroxide, and vitamin E, thus indicating complex interactions between water and nutrient contents, changes in cellular redox state and endogenous hormone concentrations. Results also suggested crosstalk between activation of mechanisms for drought stress tolerance (as mediated by ABA) and biotic stress resistance (mediated by jasmonates), in which vitamin E levels may serve as a control point. It is concluded that, aside from a tight ABA-associated regulation of stomatal closure during the dry season, crosstalk between activation of abiotic and biotic defences, and nutrient accumulation in leaves may be important modulators of plant stress responses in plants growing in their natural habitat. PMID:25769340

  12. Arabidopsis plastid AMOS1/EGY1 integrates abscisic acid signaling to regulate global gene expression response to ammonium stress

    KAUST Repository

    Li, Baohai

    2012-10-12

    Ammonium (NH4 +) is a ubiquitous intermediate of nitrogen metabolism but is notorious for its toxic effects on most organisms. Extensive studies of the underlying mechanisms of NH4 + toxicity have been reported in plants, but it is poorly understood how plants acclimate to high levels of NH4 +. Here, we identified an Arabidopsis (Arabidopsis thaliana) mutant, ammonium overly sensitive1 (amos1), that displays severe chlorosis under NH4 + stress. Map-based cloning shows amos1 to carry a mutation in EGY1 (for ethylene-dependent, gravitropism-deficient, and yellow-green-like protein1), which encodes a plastid metalloprotease. Transcriptomic analysis reveals that among the genes activated in response to NH4 +, 90% are regulated dependent on AMOS1/ EGY1. Furthermore, 63% of AMOS1/EGY1-dependent NH4 +-activated genes contain an ACGTG motif in their promoter region, a core motif of abscisic acid (ABA)-responsive elements. Consistent with this, our physiological, pharmacological, transcriptomic, and genetic data show that ABA signaling is a critical, but not the sole, downstream component of the AMOS1/EGY1-dependent pathway that regulates the expression of NH4 +-responsive genes and maintains chloroplast functionality under NH4 + stress. Importantly, abi4 mutants defective in ABA-dependent and retrograde signaling, but not ABA-deficient mutants, mimic leaf NH4 + hypersensitivity of amos1. In summary, our findings suggest that an NH4 +-responsive plastid retrograde pathway, which depends on AMOS1/EGY1 function and integrates with ABA signaling, is required for the regulation of expression of the presence of high NH4 + levels. © 2012 American Society of Plant Biologists. All Rights Reserved.

  13. OsERF2 controls rice root growth and hormone responses through tuning expression of key genes involved in hormone signaling and sucrose metabolism.

    Science.gov (United States)

    Xiao, Guiqing; Qin, Hua; Zhou, Jiahao; Quan, Ruidang; Lu, Xiangyang; Huang, Rongfeng; Zhang, Haiwen

    2016-02-01

    Root determines plant distribution, development progresses, stress response, as well as crop qualities and yields, which is under the tight control of genetic programs and environmental stimuli. Ethylene responsive factor proteins (ERFs) play important roles in plant growth and development. Here, the regulatory function of OsERF2 involved in root growth was investigated using the gain-function mutant of OsERF2 (nsf2857) and the artificial microRNA-mediated silenced lines of OsERF2 (Ami-OsERF2). nsf2857 showed short primary roots compared with the wild type (WT), while the primary roots of Ami-OsERF2 lines were longer than those of WT. Consistent with this phenotype, several auxin/cytokinin responsive genes involved in root growth were downregulated in nsf2857, but upregulated in Ami-OsERF2. Then, we found that nsf2857 seedlings exhibited decreased ABA accumulation and sensitivity to ABA and reduced ethylene-mediated root inhibition, while those were the opposite in Ami-ERF2 plants. Moreover, several key genes involved in ABA synthesis were downregulated in nsf2857, but unregulated in Ami-ERF2 lines. In addition, OsERF2 affected the accumulation of sucrose and UDPG by mediating expression of key genes involved in sucrose metabolism. These results indicate that OsERF2 is required for the control of root architecture and ABA- and ethylene-response by tuning expression of series genes involved in sugar metabolism and hormone signaling pathways.

  14. Identification of Quantitative Trait Loci for ABA Sensitivity at Seed Germination and Seedling Stages in Rice%水稻种子萌发和苗期ABA敏感性的QTL定位分析

    Institute of Scientific and Technical Information of China (English)

    游均; 李强; 岳兵; 薛为亚; 罗利军; 熊立仲

    2006-01-01

    植物激素ABA参与不同的生理过程,尤其是在种子发育和非生物逆境的适应都需要ABA的调控.以水稻珍汕97和旱稻IRAT109为亲本的重组自交系群体为材料,分别调查种子发芽和苗期对ABA的敏感程度.种子发芽阶段以ABA处理下的相对发芽势(Relative germination vigor,RGV)和相对发芽率(Relative germination rate,RGR)为指标,苗期以ABA喷施处理下的卷叶程度(Leaf rolling scores by ABA spaying,LRS)和含ABA水培条件下的卷叶程度(Leaf rolling scores by ABA culturing,LRC)为指标.性状相关分析表明发芽阶段的相对发芽势与苗期卷叶程度呈显著正相关.用复合区间作图法和混合线性模型对ABA敏感性QTL定位和上位性效应分析.两种软件检测到的主效QTL位点大致相同.共检测到5个单位点QTL和6对上位性QTL与发芽阶段的ABA敏感性有关;8个单位点QTL和5对上位性QTL与水稻苗期对ABA的敏感性有关;在苗期,两种ABA处理条件下共检测到两个共同的QTL;仅一个共同的QTL同时控制发芽阶段和苗期对ABA的敏感性.这些研究结果说明,水稻对ABA的敏感性同时受单位点的多基因和上位性基因控制;而且控制种子萌发阶段发芽势和苗期对ABA敏感性的遗传基础有很大的不同.%Abscisic acid (ABA) is one of the important plant hormones, which plays a critical role in seed development and adaptation to abiotic stresses. The sensitivity of rice (Oryza sativa L.) to exogenous ABA at seed germination and seedling stages was investigated in the recombinant inbred line (RIL) population derived from a cross between irrigated rice Zhenshan 97 and upland rice IRAT109, using relative germination vigor (RGV), relative germination rate (RGR) and leaf rolling scores of spraying (LRS) or culturing (LRC) with ABA as sensitivity indexes. The phenotypic correlation analysis revealed that only RGV at germination stage was positively correlated to ABA sensitivity at seedling stage

  15. ORA47 (octadecanoid-responsive AP2/ERF-domain transcription factor 47) regulates jasmonic acid and abscisic acid biosynthesis and signaling through binding to a novel cis-element.

    Science.gov (United States)

    Chen, Hsing-Yu; Hsieh, En-Jung; Cheng, Mei-Chun; Chen, Chien-Yu; Hwang, Shih-Ying; Lin, Tsan-Piao

    2016-07-01

    ORA47 (octadecanoid-responsive AP2/ERF-domain transcription factor 47) of Arabidopsis thaliana is an AP2/ERF domain transcription factor that regulates jasmonate (JA) biosynthesis and is induced by methyl JA treatment. The regulatory mechanism of ORA47 remains unclear. ORA47 is shown to bind to the cis-element (NC/GT)CGNCCA, which is referred to as the O-box, in the promoter of ABI2. We proposed that ORA47 acts as a connection between ABA INSENSITIVE1 (ABI1) and ABI2 and mediates an ABI1-ORA47-ABI2 positive feedback loop. PORA47:ORA47-GFP transgenic plants were used in a chromatin immunoprecipitation (ChIP) assay to show that ORA47 participates in the biosynthesis and/or signaling pathways of nine phytohormones. Specifically, many abscisic acid (ABA) and JA biosynthesis and signaling genes were direct targets of ORA47 under stress conditions. The JA content of the P35S:ORA47-GR lines was highly induced under wounding and moderately induced under water stress relative to that of the wild-type plants. The wounding treatment moderately increased ABA accumulation in the transgenic lines, whereas the water stress treatment repressed the ABA content. ORA47 is proposed to play a role in the biosynthesis of JA and ABA and in regulating the biosynthesis and/or signaling of a suite of phytohormone genes when plants are subjected to wounding and water stress. PMID:26974851

  16. ALA Altered ABA Content of Winter Oilseed Rape( Brassica napus L. )Seedling%ALA改变了油菜幼苗体内ABA的含量

    Institute of Scientific and Technical Information of China (English)

    张树杰; 李玲; 张春雷; 李光明

    2011-01-01

    [目的]本文的目的是为了揭示ALA处理对冬油菜(Brassica napus L.)幼苗生长的影响及作用机理.[方法]采用营养液培养的方法研究ALA溶液浸种对中双9号油菜幼苗生长及体内ABA含量的影响.实验设置4个处理,分别用0、25、50和75mg/L ALA(CK、A1、A2和A3)溶液浸种6h.[结果]除了A3处理使油菜幼苗于重轻微降低之外,ALA浸种使油菜幼苗(根系和地上部)干重、净光合速率、燕腾速率和气孔导度较对照显著增加.与对照相比,ALA浸种使油菜幼苗体内和木质部伤流液中ABA含量出现不同程度的增加.[结论]提高体内ABA含量可能是ALA浸种处理促进冬油菜幼苗在冬前低温阶段生长的主要原因.%[ Objective ] The paper was to explore the impact of 5-aminolevunic acid (ALA) treatment on growth of winter oilseed rape ( Brassica napus L. ) seedlings and its mechanism. [ Method ] The effects of ALA on abscisic acid (ABA) contents in plant organs and xylem saps were investigated through hydroponic experiment. Four treatments including seed soaking with 0, 25, 50 and 75 mg/L ALA solutions ( CK, A1, A2 and A3) for 6 h were set in the test. [ Result] In addition to A3 treatment which made the dry weights of oilseed rape seedlings slightly decrease, after seed soaking with ALA, dry weights, net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) of plants significantly increased compared with control. ABA concentrations in plant shoots and xylem saps increased in different levels after seed soaking with ALA. [ Conclusion] The increasing endogenous ABA contents might be an explanation for promotion effect of ALA application on the growth of winter oilseed rape seedling.

  17. Electronic and magnetic properties of double perovskites A{sub 2}FeReO{sub 6} (A=Ba, Ca)

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Juan Ignacio [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, 1428 Buenos Aires (Argentina); Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Avenida General Paz y Constituyentes, 1650 San Martin (Argentina); Weht, Ruben, E-mail: ruweht@cnea.gov.a [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Avenida General Paz y Constituyentes, 1650 San Martin (Argentina); Instituto de Tecnologia Prof. Jorge A. Sabato, Universidad Nacional de San Martin/CNEA (Argentina)

    2009-10-01

    We have studied the magnetic and electronic properties of double perovskites A{sub 2}FeReO{sub 6} with A=Ba and Ca using ab initio methods based on density functional theory. It has been shown that when changing Ba by Ca the system undergoes a metal-insulator transition coincidentally to a structural phase transition, even if conduction band fillings are not significantly changed. Our results suggest that only considering a quite large correlation term on the Re site could explain an insulating character for Ca{sub 2}FeReO{sub 6}. Instead, we found that small correlations could induce a bad metallic behavior as suggested in more recent experiments.

  18. Effects of chilling and ABA on [3H]gibberellin A4 metabolism in somatic embryos of grape (Vitis vinifera L. x V. rupestris Scheele)

    International Nuclear Information System (INIS)

    Previous work has indicated that changes in gibberellin (GA) metabolism may be involved in chilling-induced release from dormancy in somatic embryos of grape (Vitis vinifera L. x V. rupestris Scheele). The authors have chilled somatic embryos of grape for 2, 4, or 8 weeks, then incubated them with [3H]GA4 (of high specific activity, 4.81 x 1019 becquerel per millimole) for 48 hours at 260C. Chilling had little effect on the total amount of free [3H]GA-like metabolites formed during incubation at 260C, but did change the relative proportions of individual metabolites. The amount of highly water-soluble [3H] metabolites formed at 260C decreased in embryos chilled for 4 or 8 weeks. The concentration of endogeneous GA precursors (e.g., GA12 aldehyde-, kaurene, and kaurenoic acid-like substances) increased in embryos chilled for 4 or 8 weeks. Treatment with abscisic acid (ABA) (known to inhibit germination in grape embryos) concurrent with [3H]GA4 treatment at 260C, reduced the uptake of [3H] GA4 but had little effect on the qualitative spectrum of metabolites. However, in the embryos chilled for 8 weeks and then treated with ABA for 48 hours at 260C, there was a higher concentration of GA precursors than in untreated control embryos. Chilled embryos thus have an enhanced potential for an increase in free GAs through synthesis from increased amounts of GA precursors, or through a reduced ability to form highly water-soluble GA metabolites (i.e., GA conjugates or polyhydroxylated free GAs)

  19. Foliar abscisic acid-to-ethylene accumulation and response regulate shoot growth sensitivity to mild drought in wheat

    OpenAIRE

    Valluru, Ravi; Davies, William John; Reynolds, Matthew; Dodd, Ian Charles

    2016-01-01

    Although, plant hormones play an important role in adjusting growth in response to environmental perturbation, the relative contributions of abscisic acid (ABA) and ethylene remain elusive. Using six spring wheat genotypes differing for stress tolerance, we show that young seedlings of the drought-tolerant (DT) group maintained or increased shoot dry weight (SDW) while the drought-susceptible (DS) group decreased SDW in response to mild drought. Both the DT and DS groups increased endogenous ...

  20. Foliar abscisic acid-to-ethylene accumulation and response regulate shoot growth sensitivity to mild drought in wheat

    OpenAIRE

    Ravi eValluru; William J eDavies; Matthew P eReynolds; Ian C eDodd

    2016-01-01

    Although plant hormones play an important role in adjusting growth in response to environmental perturbation, the relative contributions of abscisic acid (ABA) and ethylene remain elusive. Using six spring wheat genotypes differing for stress tolerance, we show that young seedlings of the drought-tolerant (DT) group maintained or increased shoot dry weight (SDW) while the drought-susceptible (DS) group decreased SDW in response to mild drought. Both the DT and DS groups increased endogenous A...

  1. Abscisic acid refines the synthesis of chloroplast proteins in maize (Zea mays in response to drought and light.

    Directory of Open Access Journals (Sweden)

    Xiuli Hu

    Full Text Available To better understand abscisic acid (ABA regulation of the synthesis of chloroplast proteins in maize (Zea mays L. in response to drought and light, we compared leaf proteome differences between maize ABA-deficient mutant vp5 and corresponding wild-type Vp5 green and etiolated seedlings exposed to drought stress. Proteins extracted from the leaves of Vp5 and vp5 seedlings were used for two-dimensional electrophoresis (2-DE and subsequent matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF mass spectrometry (MS. After Coomassie brilliant blue staining, approximately 450 protein spots were reproducibly detected on 2-DE gels. A total of 36 differentially expressed protein spots in response to drought and light were identified using MALDI-TOF MS and their subcellular localization was determined based on the annotation of reviewed accession in UniProt Knowledgebase and the software prediction. As a result, corresponding 13 proteins of the 24 differentially expressed protein spots were definitely localized in chloroplasts and their expression was in an ABA-dependent way, including 6 up-regulated by both drought and light, 5 up-regulated by drought but down-regulated by light, 5 up-regulated by light but down-regulated by drought; 5 proteins down-regulated by drought were mainly those involved in photosynthesis and ATP synthesis. Thus, the results in the present study supported the vital role of ABA in regulating the synthesis of drought- and/or light-induced proteins in maize chloroplasts and would facilitate the functional characterization of ABA-induced chloroplast proteins in C(4 plants.

  2. A Truncated Arabidopsis NUCLEOSOME ASSEMBLY PROTEIN 1,AtNAP1;3T,Alters Plant Growth Responses to Abscisic Acid and Salt in the Atnap 1;3-2 Mutant

    Institute of Scientific and Technical Information of China (English)

    Zi-Qiang Liu; Juan Gao; Ai-Wu Dong

    2009-01-01

    Chromatin remodeling is thought to have crucial roles in plant adaptive response to environmental stimulus.Here,we report that,in Arebidopsis,the evolutionarily conserved histone chaperone,NUCLEOSOME ASSEMBLY PROTEIN 1 (NAP1),is involved in plant response to abscisic acid (ABA),a phytohormone important in stress adaptation.We show that simultaneous loss-of-function of AtNAP1;1,AtNAP1;2,and AtNAP1;3 (the triple mutant m123-1) caused a slight hypersensitive response to ABA in seedling growth.Strikingly,the other triple mutant m123-2 containing a different mutant allele of AtNAP1;3,the Atnap1;3-2 allele,showed a hyposensitive response to ABA and a decreased tolerance to salt stress.This ABAhyposensitive and salt response phenotype specifically associated with the Atnap1;3-2 mutant allele.We show that this mutant allele produced a truncated protein,AtNAP1;3T,which lacks 34 amino acids at the C-terminus compared to the wild-type protein AtNAP1;3.We further show that the heterozygous plants containing the Atnap1;3-2 mutant allele as well as transgenic plants overexpressing AtNAP1;3T exhibit ABA-hyposensitive phenotype.It thus indicates that AtNAP1;3T functions as a dominant negative factor in ABA response.The expression of some ABA-responsive genes,including genes encoding protein kinases and transcription regulators,was found perturbed in the mutant and in the AtNAP1;3T transgenic plants.Taken together,our study uncovered AtNAP1 proteins as positive regulators and AtNAP1;3T as a negative regulator in ABA signaling pathways,providing a novel link of chromatin remodeling to hormonal and stress responses.

  3. Expression analysis of bZIP transcription factor encoding genes in response to water deficit stress in rice.

    Science.gov (United States)

    Ali, Kishwar; Rai, R D; Tyagi, Aruna

    2016-05-01

    In plants, basic region/leucine zipper motif (bZIP) transcription factors regulate several developmental processes and activate genes in response to biotic and abiotic stresses. Role of stress responsive bZIP transcription factors was studied in paddy in relation to different stages of development and water deficit stress (WDS) in a drought tolerant cultivar N22 and susceptible IR 64. Further, relative water content (RWC), membrane stability index (MSI) and abscisic acid (ABA) content were measured as indices of WDS at different stages of development and levels of stress. Expression of stress responsive bZIP transcription factors was directly correlated to developmental stage and WDS and indirectly to RWC, MSI and ABA content. PMID:27319052

  4. 外源 ABA 浸种对冬油菜种子萌发及幼苗抗寒性的诱导效应%Inducing effects of exogenous ABA on seed germination and cold tolerance of winter rape seedlings

    Institute of Scientific and Technical Information of China (English)

    方彦; 武军艳; 孙万仓; 杨晓娟; 韩慧敏; 韩亚伟; 陈亚平

    2014-01-01

    In order to investigate the inducing effects of cold tolerance of winter rapeseed by exogenous ABA in northern drought and cold region ,two winter rapeseed cultivars Longyou 6 (cold resistant ) and Tianyou 2 (cold suscepti-ble ) were presoaked with different concentrations of ABA .The effect of different ABA concentrations on seed germination and related cold resistance indexes of winter rapeseed were studied under normal temperature and cold stress .The results showed that the concentration of 10~70 mg·L-1 promoted seed germination ,while that of 80 mg·L-1 abscisic acid solu-tion lowed germination ability and percentage .The recommended concentration of abscisic acid is 30 mg·L-1 ,increasing superoxide dismutase (SOD ) ,peroxidase (POD ) and catalase (CAT ) activities ,alleviating the chlorophyll degradation , and elevating proline content but decreasing MDA content ,the product of membrane lipid peroxidation .In addition ,the effects of exogenous ABA on winter rapeseed varied with varieties ,and it was obvious for Longyou 6 with high chilling re-sistance .%为探讨外源脱落酸(ABA )对北方寒旱区冬油菜幼苗抗寒性的诱导效应,试验分别用不同浓度的ABA对超强抗寒性白菜型冬油菜品种“陇油6号”和弱抗寒性品种“天油2号”进行浸种处理,研究不同浓度ABA浸种对冬油菜种子萌发及常温和低温胁迫条件下相关抗寒指标的影响。结果表明,10~70 mg · L-1 ABA处理促进了种子萌发,80 mg·L-1ABA处理对发芽率和发芽势有抑制作用;30 mg·L-1浓度的ABA对冬油菜抗寒性诱导效果最佳,可显著(P<0.05)提高冬油菜幼苗抗氧化酶(SOD、POD和CAT)活性,延缓叶绿素含量的降低,增加叶片脯氨酸含量,减缓膜脂过氧化产物丙二醛的积累;外源ABA处理在品种上存在差异,对抗寒性强的品种陇油6号效果明显。

  5. Differentiation of photoperiod-induced ABA and soluble sugar responses of two quinoa (Chenopodium quinoa willd.) cultivars

    DEFF Research Database (Denmark)

    Bendevis, Mira Arpe; Sun, Yujie; Shabala, Sergey;

    2014-01-01

    Adaptation of quinoa (Chenopodium quinoa Willd.) to new regions demands acclimation to day-length, in addition to a host of other abiotic factors. To further elucidate the effects of photoperiod on development of quinoa, two differently adapted cultivars, Achachino (short day) from Bolivia and Ti...

  6. A Randomized Clinical Trial Comparison between Pivotal Response Treatment (PRT) and Adult-Driven Applied Behavior Analysis (ABA) Intervention on Disruptive Behaviors in Public School Children with Autism

    Science.gov (United States)

    Mohammadzaheri, Fereshteh; Koegel, Lynn Kern; Rezaei, Mohammad; Bakhshi, Enayatolah

    2015-01-01

    Children with autism often demonstrate disruptive behaviors during demanding teaching tasks. Language intervention can be particularly difficult as it involves social and communicative areas, which are challenging for this population. The purpose of this study was to compare two intervention conditions, a naturalistic approach, Pivotal Response…

  7. Botulinum toxin-induced facial muscle paralysis affects amygdala responses to the perception of emotional expressions: preliminary findings from an A-B-A design

    OpenAIRE

    Kim, M. Justin; Neta, Maital; Davis, F. Caroline; Ruberry, Erika J.; Dinescu, Diana; Heatherton, Todd F.; Stotland, Mitchell A; Whalen, Paul J.

    2014-01-01

    Background It has long been suggested that feedback signals from facial muscles influence emotional experience. The recent surge in use of botulinum toxin (BTX) to induce temporary muscle paralysis offers a unique opportunity to directly test this “facial feedback hypothesis.” Previous research shows that the lack of facial muscle feedback due to BTX-induced paralysis influences subjective reports of emotional experience, as well as brain activity associated with the imitation of emotional fa...

  8. Arabidopsis type B cytokinin response regulators ARR1, ARR10, and ARR12 negatively regulate plant responses to drought.

    Science.gov (United States)

    Nguyen, Kien Huu; Ha, Chien Van; Nishiyama, Rie; Watanabe, Yasuko; Leyva-González, Marco Antonio; Fujita, Yasunari; Tran, Uven Thi; Li, Weiqiang; Tanaka, Maho; Seki, Motoaki; Schaller, G Eric; Herrera-Estrella, Luis; Tran, L S

    2016-03-15

    In this study, we used a loss-of-function approach to elucidate the functions of three Arabidopsis type B response regulators (ARRs)--namely ARR1, ARR10, and ARR12--in regulating the Arabidopsis plant responses to drought. The arr1,10,12 triple mutant showed a significant increase in drought tolerance versus WT plants, as indicated by its higher relative water content and survival rate on drying soil. This enhanced drought tolerance of arr1,10,12 plants can be attributed to enhanced cell membrane integrity, increased anthocyanin biosynthesis, abscisic acid (ABA) hypersensitivity, and reduced stomatal aperture, but not to altered stomatal density. Further drought-tolerance tests of lower-order double and single mutants indicated that ARR1, ARR10, and ARR12 negatively and redundantly control plant responses to drought, with ARR1 appearing to bear the most critical function among the three proteins. In agreement with these findings, a comparative genome-wide analysis of the leaves of arr1,10,12 and WT plants under both normal and dehydration conditions suggested a cytokinin (CK) signaling-mediated network controlling plant adaptation to drought via many dehydration/drought- and/or ABA-responsive genes that can provide osmotic adjustment and protection to cellular and membrane structures. Expression of all three ARR genes was repressed by dehydration and ABA treatments, inferring that plants down-regulate these genes as an adaptive mechanism to survive drought. Collectively, our results demonstrate that repression of CK response, and thus CK signaling, is one of the strategies plants use to cope with water deficit, providing novel insight for the design of drought-tolerant plants by genetic engineering.

  9. In situ assessment of morpho-physiological response of wheat (triticum aestivum L.) genotypes to drought

    International Nuclear Information System (INIS)

    In situ studies were conducted to assess the morpho-physiological responses of wheat genotypes to PEG-induced water stress. Wheat genotypes were raised in hydroponic cultures where plants were nourished with half strength Hoagland solution. Plants were exposed to 00, 10, 20, 30 and 40% PEG-6000 at 4-leaf stage. PEG was applied in split doses at the rate of 10% with an interval of 15 days. Significant differences (p=0.05) were recorded for all the parameters studied due to genotypes and PEG concentrations. Wheat genotypes showed negative but variable response to PEG concentrations for shoot length, root length, root/ shoot ratio and root mass whereas PEG imposed stress had positive impact on proline content and abscisic acid (ABA). Genotype Khattakwal attained maximum shoot length in PEG induced stress. Maximum root/shoot ratio and root mass was recorded in Ghaznavi-98 while Tatara and Khattakwal attained maximum relative water content. Endogenous proline and ABA content increased up to 10 fold in response to 40% PEG. Maximum proline was accumulated by Khattakwal whereas maximum ABA by ICP-3. (author)

  10. Effect of exogenous ABA on physiological indexes of Phalaenopsis under low temperature stress%外源ABA对低温胁迫下蝴蝶兰叶片生理指标的影响

    Institute of Scientific and Technical Information of China (English)

    田丹青; 葛亚英; 刘晓静; 潘刚敏; 沈晓岚; 潘晓韵; 郁永明

    2013-01-01

    The study was to reveal effects of exogenous ABA on chilling resistance of Phalaenopsis seedlings under low temperature stress. Leaves were sprayed with 50 mg · L ABA under room temperature for 1 day, and then plants were treated under 6℃ for 4 days. Plants treated with water were used as the control. Relative electric conductivity (REC) , malondialdehyde (MDA) and proline content, and activities of catalase (CAT) and superoxide dismutase (SOD) were determined on four days after cold treatment. The results showed that ABA treatment delayed the increase of REC and MDA content, reduced the accumulation of proline, and increased the activities of SOD and CAT. These above results indicated ABA treatment could increase the activities of antioxidant enzymes, reduce the reaction of membrane lipid peroxidation and the infiltration of membrane, and thus decrease the damage under low temperature in Phalaenopsis plants.%为研究脱落酸(ABA)对蝴蝶兰抗寒性的影响,以蝴蝶兰中苗为试材,叶面喷施50 mg· L-1脱落酸(ABA)1 d后,于6℃低温胁迫4d,以清水喷施为对照,在低温处理0,1,2,3和4d后测定叶片相对电导率、丙二醛(MDA)含量、脯氨酸(Pro)含量、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性.结果表明:喷施ABA可以延缓蝴蝶兰叶片的相对电导率和MDA含量的上升,减少Pro的累积量,提高CAT和SOD的活性.说明喷施ABA提高了蝴蝶兰叶片的抗氧化酶活性,减少了膜脂过氧化产物的积累,降低了细胞膜透性,从而减轻了低温胁迫的伤害.

  11. Self-Assembly and Critical Aggregation Concentration Measurements of ABA Triblock Copolymers with Varying B Block Types: Model Development, Prediction, and Validation.

    Science.gov (United States)

    Aydin, Fikret; Chu, Xiaolei; Uppaladadium, Geetartha; Devore, David; Goyal, Ritu; Murthy, N Sanjeeva; Zhang, Zheng; Kohn, Joachim; Dutt, Meenakshi

    2016-04-21

    The dissipative particle dynamics (DPD) simulation technique is a coarse-grained (CG) molecular dynamics-based approach that can effectively capture the hydrodynamics of complex systems while retaining essential information about the structural properties of the molecular species. An advantageous feature of DPD is that it utilizes soft repulsive interactions between the beads, which are CG representation of groups of atoms or molecules. In this study, we used the DPD simulation technique to study the aggregation characteristics of ABA triblock copolymers in aqueous medium. Pluronic polymers (PEG-PPO-PEG) were modeled as two segments of hydrophilic beads and one segment of hydrophobic beads. Tyrosine-derived PEG5K-b-oligo(desaminotyrosyl tyrosine octyl ester-suberate)-b-PEG5K (PEG5K-oligo(DTO-SA)-PEG5K) block copolymers possess alternate rigid and flexible components along the hydrophobic oligo(DTO-SA) chain, and were modeled as two segments of hydrophilic beads and one segment of hydrophobic, alternate soft and hard beads. The formation, structure, and morphology of the initial aggregation of the polymer molecules in aqueous medium were investigated by following the aggregation dynamics. The dimensions of the aggregates predicted by the computational approach were in good agreement with corresponding results from experiments, for the Pluronic and PEG5K-oligo(DTO-SA)-PEG5K block copolymers. In addition, DPD simulations were utilized to determine the critical aggregation concentration (CAC), which was compared with corresponding results from an experimental approach. For Pluronic polymers F68, F88, F108, and F127, the computational results agreed well with experimental measurements of the CAC measurements. For PEG5K-b-oligo(DTO-SA)-b-PEG5K block polymers, the complexity in polymer structure made it difficult to directly determine their CAC values via the CG scheme. Therefore, we determined CAC values of a series of triblock copolymers with 3-8 DTO-SA units using DPD

  12. Effect of Foliar Spray Treatment with S-ABA on Water Consumption of Corn Plant%S-诱抗素对玉米植株水分消耗的影响

    Institute of Scientific and Technical Information of China (English)

    刘刚; 文启; 肖亮

    2011-01-01

    本文测试了S-诱抗素叶面喷施处理后玉米植株在高温干旱协迫下水分消耗等项目,结果表明:S-诱抗素处理可以缩小气孔导度,减少叶片蒸腾速率,提高了玉米植株的保水能力,减少了水分消耗.%In this trial, the effect of foliar spraying S-ABA on the water consumption of com plant under high temperature and drought stress was studied. The results showed that the leaf stomata conductance fall , and the leaf transpiration rate decreased, and the com plant water consumption decreased by spraying S-ABA under the high temperature and drought stress.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening

    Science.gov (United States)

    Meir, Sagit; Panizel, Irina; Puig, Clara Pons; Hao, Yanwei; Yifhar, Tamar; Yasuor, Hagai; Zouine, Mohamed; Bouzayen, Mondher; Granell Richart, Antonio; Rogachev, Ilana; Aharoni, Asaph

    2016-01-01

    The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA). Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process. PMID:26959229

  15. AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.

    Science.gov (United States)

    Breitel, Dario A; Chappell-Maor, Louise; Meir, Sagit; Panizel, Irina; Puig, Clara Pons; Hao, Yanwei; Yifhar, Tamar; Yasuor, Hagai; Zouine, Mohamed; Bouzayen, Mondher; Granell Richart, Antonio; Rogachev, Ilana; Aharoni, Asaph

    2016-03-01

    The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA). Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process.

  16. AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.

    Science.gov (United States)

    Breitel, Dario A; Chappell-Maor, Louise; Meir, Sagit; Panizel, Irina; Puig, Clara Pons; Hao, Yanwei; Yifhar, Tamar; Yasuor, Hagai; Zouine, Mohamed; Bouzayen, Mondher; Granell Richart, Antonio; Rogachev, Ilana; Aharoni, Asaph

    2016-03-01

    The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA). Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process. PMID:26959229

  17. Assessing Psychological Functioning in Metabolic Disorders: Validation of the Adaptive Behavior Assessment System, Second Edition (ABAS-II), and the Behavior Rating Inventory of Executive Function (BRIEF) for Identification of Individuals at Risk.

    Science.gov (United States)

    Waisbren, Susan E; He, Jianping; McCarter, Robert

    2015-01-01

    Long-term follow-up of neuropsychological functioning in metabolic disorders remains difficult due to limited opportunities for comprehensive neuropsychological evaluations. This study examined the validity of using the Adaptive Behavior Assessment System, Second Edition (ABAS-II), and the Behavior Rating Inventory of Executive Function (BRIEF) for assessing developmental status in metabolic disorders and for identifying individuals at risk for cognitive deficits. Results from individuals with urea cycle disorders, phenylketonuria, galactosemia, and fatty acid oxidation disorders were obtained on the ABAS-II and BRIEF and were compared to results obtained from neuropsychological testing performed on the same day. Correlations between scores on the ABAS-II and developmental or IQ tests for individuals with urea cycle disorders ranged from 0.48 to 0.72 and concordance rates for scores greater than a standard deviation below the normative mean ranged from 69 to 89%. Correlations ranged from 0.20 to 0.68 with concordance ranging from 73 to 90% in the other metabolic disorders. For the BRIEF, correlations with other tests of executive functioning were significant for urea cycle disorders, with concordance ranging from 52 to 80%. For the other metabolic disorders, correlations ranged from -0.09 to -0.55. Concordance rates for at-risk status on the BRIEF and executive functioning tests ranged from 55% in adults to 80% in children with other metabolic disorders. These results indicate that the ABAS-II and BRIEF together can confidently be used as an adjunct or supplementary method for clinical follow-up and for research on functional status involving infants, children, and adults with metabolic disorders. PMID:25712381

  18. 外源ABA对小麦抗旱性和产量性状的影响%Effects of Exogenous ABA on Wheat Drought Resistance and Yield

    Institute of Scientific and Technical Information of China (English)

    席吉龙; 张建诚; 席凯鹏; 姚景珍; 段黎杰; 刘跃鹏

    2014-01-01

    研究了干旱胁迫下外源ABA对抗旱小麦品种晋麦47号不同生长阶段的抗旱性的效果.结果表明,一定浓度的外源ABA浸种能分别提高小麦种子发芽势211.99%、发芽率63.00%、相对发芽率62.87%,利于苗齐苗壮,增强发芽期抗旱性.苗期喷施ABA能促进幼苗生长,幼苗株高、茎叶干重、根干重分别显著提高12.74%、9.60%、13.00%,伤害率比对照降低11.51%.孕穗期喷施ABA,促进了光合作用,增强了抗旱能力,叶片相对含水率提高46.39%,叶绿素荧光参数Fv/Fm值极显著提高,增加产量9.26%.

  19. Inducing Effects and Its Biological Mechanisms of ABA on the Chilling Resistance of Sweet Pepper Seedlings%脱落酸对甜椒幼苗抗寒性的诱导效应及其机理研究

    Institute of Scientific and Technical Information of China (English)

    罗立津; 徐福乐; 翁华钦; 洪淑珠; 段留生; 李召虎

    2011-01-01

    以砂培甜椒幼苗为材料,先用不同浓度脱落酸(ABA)进行灌根处理,再分两组分别于常温(25℃~30℃)生长7 d(常温苗)或低温驯化(10℃~15℃)30 d(驯化苗)之后进行低温胁迫(5℃)处理,分析幼苗的生长状况及其细胞质膜伤害、渗透调节物质、活性氧清除系统、内源激素的变化特征,以探讨脱落酸对甜椒抗寒性的诱导效应及机理.结果显示,(1)各浓度ABA对甜椒常温苗和驯化苗的株高、茎重均无显著影响,但显著促进驯化苗的侧根生长,在低温胁迫下,显著降低驯化苗叶片的呼吸速率;(2)常温苗的相对电导率仅在10 mg/L ABA处理中比对照显著降低,而驯化苗在各处理浓度下均显著降低, MDA含量表现出与此类似的变化;(3)叶片脯氨酸、可溶性糖、可溶性蛋白、钾离子等渗透调节物质含量在各浓度ABA处理常温苗和驯化苗中均有所增加,但仅脯氨酸含量的增加达到显著水平.(4)各浓度ABA处理都一定程度上提高了常温苗的SOD活性,显著降低了常温苗的CAT和POD活性,H2O2积累量均显著降低,但对于驯化苗,1.0 mg/L和10 mg/L ABA处理却显著降低其SOD活性,POD和CAT活性无显著差异,H2O2积累量也无显著变化.(5)茎尖的ZR、JA-Me含量及IAA/ZR、均与对照无显著差异,但IAA、ABA含量、ABA/ZR比值明显提高,其中1.0和10 mg/L处理的内源ABA含量以及10 mg/L处理的ABA/ZR比值显著高于对照.研究表明,脱落酸能通过降低甜椒幼苗呼吸速率,提高叶片脯氨酸、可溶性糖、钾离子等渗透调节物质以及ABA的积累来诱导增强甜椒幼苗的抗寒性,减少活性氧自由基的产生和累积量,从而减轻低温胁迫造成的伤害,且低温驯化条件下比常温下效果更加明显.%To study the inducing effects and biological mechanisms of abscisic acid (ABA) on the chilling resistance of plant,sandy culture method was conducted to examine the effects of ABA on the lipid

  20. 植物激素ABA在水分胁迫下的功能及信号途径%Function and Signaling of Plant Hormone ABA under Water Stress

    Institute of Scientific and Technical Information of China (English)

    李保珠; 安国勇; 韩栓

    2012-01-01

    植物根系感知外界水分胁迫刺激,诱导ABA生物合成.ABA既可诱导气孔关闭或抑制气孔开放,以降低植物的蒸腾失水,又可影响植物根系发育,以抵御水分胁迫.本文就植物激素ABA及其下游信号H2O2、NO以及Ca2+等在植物生长调节方面的研究进展进行概述,以构建水分胁迫下植物生长自我调控的可能模式.%Plant roots perceive water stress and induce the synthesis of abscisic acid (ABA). ABA not only could induce stomatal closure or inhibit stomatal opening to reduce transpiration, but also regulate the development of roots and increase drought tolerance. This paper focused on the functions of plant hormone ABA and its downstream signal intermediates (H2O2, NO and Ca2+) for establishing the basic model of its regulation of plant growth under water stress.

  1. 脱落酸浸种提高萌发期水稻种子对涝渍胁迫的抗性研究%ABA Improving Rice Seeds Resistance to Waterlogging Stress during Germinating Period

    Institute of Scientific and Technical Information of China (English)

    陈思妍; 邹华文

    2013-01-01

    [ Objective ] To study the effects of ABA on the rice germination and seedling quality under waterlogging stress, and provide reference for agriculture production. [ Method] Water and 0. 1 u,mol/L ABA solution was used to submerge rice seeds for 24 hours, respectively. After the roots were 2-5 mm length, the seeds were subjected to waterlogging for 72 hours. Then the seedlings formation rate and other indexes were checked. [ Result] The results showed that compared to the control, ABA treatment increased the seedlings formation rate by 38.7% , root length by 23.6% , plant height by 13.3% , dry weight by 37.8% and relative vigor index by 34.8% , respectively. [Conclusion] These results indicated that ABA could dramatically enhance the seedlings formation rate, seedlings quality and relative vigor index of rice under waterlogging conditions.%[目的]探究脱落酸(ABA)浸种对涝渍胁迫条件下水稻种子萌发及幼苗生长的影响,为农业生产提供借鉴.[方法]分别用蒸馏水和0.1 μmoL/LABA溶液浸种24h,正常催芽萌发至胚根长2~5 mm,涝渍处理72 h,测定水稻种子的出苗率及各项形态指标.[结果]与涝渍对照相比,ABA浸种处理的出苗率、根长、株高、干重、相对活力指数分别增加了38.7%、23.6%、13.3%、37.8%和34.8%.[结论] ABA处理可显著提高涝渍条件下水稻种子的出苗率、秧苗素质及种子相对活力指数.

  2. 桑树脱落酸生物合成相关基因的鉴定及转录表达分析%Characterization and Transcriptional Expression Analysis of ABA Biosynthesis Related Genes from Mulberry (Morus albaL.)

    Institute of Scientific and Technical Information of China (English)

    朱攀攀; 余茂德; 刘长英; 赵爱春; 裴汭超; 李军; 王晓红; 李镇刚; 王茜龄; 鲁成

    2015-01-01

    【目的】9-顺式环氧类胡萝卜素双加氧酶(NCED)、醛氧化酶(AAO)和玉米黄质环氧化酶(ZEP)在脱落酸(abscisic acid,ABA)间接途径合成中发挥主要调节作用,它们是ABA合成相关基因。以桑树栽培品种嘉陵40号(Morus atropurpureaRoxb.)果实为材料,测定其发育过程中ABA的含量,分析桑椹成熟过程中ABA合成相关基因的转录表达、ABA 及其合成抑制剂对果实发育的影响,为研究 ABA 在桑椹成熟和衰老过程中的作用机制提供基础数据。【方法】根据从单倍体川桑(Morus notabilisSchneid.)基因组数据库(http://morus.swu. edu.cn/morusdb)下载的ABA合成相关基因序列,对其DNA及推导的氨基酸序列进行分析。使用RNAiso Plus (TaKaRa)提取总RNA。以cDNA为模板,利用real-time PCR方法检测不同时期和不同处理桑椹中ABA合成相关基因的转录表达差异。利用高效液相色谱法,测定桑椹发育过程中的ABA含量。【结果】在川桑基因组数据库筛选鉴定到6个ABA合成相关基因:1个MnAAO、2个MnZEP和3个MnNCED。MnNCED1-3氨基酸序列高度保守,聚类分析表明它们与双子叶果树NCEDs序列同源性较高,与单子叶植物同源性较低;转录分析表明它们在叶中转录水平相对高于其他组织,在根中最低。其中MnNCED2和MnNCED3在根、皮、冬芽、雄花、叶中的转录水平较高。随着果实的发育,ABA含量在转色期开始逐渐上升。外源ABA处理后,桑椹脱落率升高,而氟啶酮(fluridone)可以抑制桑椹的脱落。MnNCED1-3在果实发育中后期的转录水平较高,与ABA含量的升高相一致,而MnAAO和MnZEP1-2在中后期下调。离体桑椹经ABA处理后,MnNCED1、MnAAO和MnZEP1的转录水平直到第4天才出现上调,MnNCED3在第3天和第4天被上调,MnZEP2一直上调;氟啶酮处理后MnNCED1和MnZEP2的转录表达量只在第1天和第3

  3. 1958-2010年阿坝州炭疽流行状况分析%Prevalence of Anthrax in Aba Prefecture, 1958 -2010

    Institute of Scientific and Technical Information of China (English)

    敬琼

    2012-01-01

    目的 分析阿坝州1958 -2010年炭疽发病情况,找出发病规律和特点,探讨有效降低炭疽病发病的措施和方法.方法 对53年来的炭疽疫情数据进行流行病学分析.结果 53年来累计报告炭疽病例1 349例,死亡21例,年均发病率3.47/10万、死亡率0.06/10万.全年均有病例报告,但集中在4~10月,3个牧区县的发病占报告总数的89.03%;职业以牧民为主,发病年龄集中在20~44岁.1958 - 2001年发病率在0.8/10万~2.52/10万之间,2002-2010年发病率在6.33/10万~12.66/10万之间.结论 阿坝州1958 -2001年炭疽发病较平稳,2002年起发病呈逐年上升趋势,且发病主要在牧区,应加强健康教育和畜牧业管理,做好疫点、外环境消毒和预防接种,有效控制牧区炭疽流行.%Objective By analyzing the incidence of anthrax in Aba prefecture from year 1958 to 2010, to find out the rules and features of the incidence, and explore effective measures to reduce the incidence of anthrax. Methods Data of anthrax epidemics in 53 years (1958 -2010) was analyzed with epidemiological methods. Results Totally 1 349 anthrax cases were reported in 53 years, with 21 death cases. The annual incidence rate was 3.47/105, and case mortality rate was 0. 06/105. Cases were reported throughout the year, and concentrated in period of April to October, 89. 03% cases were from 3 pastoral counties. Professional was mainly pas-toralists, and cases concentrated in 20 -44 years old. Annual incidence rate during 1958 -2001 fluctuated within 0. 8/105 -2. 52/105, and annual incidence rate was from 6. 33/105 to 12. 66/105 during 2002 -2010. Conclusions The incidence of anthrax was stable in Aba prefecture during 1958 - 2001, followed by the in- , creasing since 2002 year by year, and mainly in pastoral areas. Health education and animal husbandry management should be strengthened, with epidemic focus and external environment disinfection and vaccination, to control the prevalence of

  4. Soil concentrations and soil-air exchange of organochlorine pesticides along the Aba profile, east of the Tibetan Plateau, western China

    Science.gov (United States)

    Liu, Hongxia; Qi, Shihua; Yang, Dan; Hu, Ying; Li, Feng; Liu, Jia; Xing, Xinli

    2013-12-01

    Mianzhu—Aba profile, east of the Tibetan Plateau, was selected to study the occurrence of organochlorine pesticides (OCPs) along an altitudinal gradient. Dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs) and Aldrin, Dieldrin and Endrin (Drins) in surface soils were detected in winter (March) and summer (July). Soil concentrations (ng·g-1, dw) in winter and summer ranged as follws: DDTs, 0.37-179.16 and 0.32-42.57; HCHs, 0.14-10.76 and 0.55-32.71; Drins, N.D-3.99 and 0.02-6.93, respectively. Main soil OCPs were p, p'-DDT, p, p'-DDE, β-HCH and Drins, among which Drins were rarely reported in current literature of the Tibetan Plateau. Higher OCP concentrations in the profile were attributed close to the agricultural fields of the Sichuan Basin, current lindane and nondicofol DDTs inputs, and also long-range atmospheric transport from abroad. Soil OCP concentrations underwent obvious seasonal variation, with higher DDTs in winter and higher HCHs and Drins in summer. It may be caused by climatic conditions, summer monsoon type, and physico-chemical properties of such contaminants. Though "rest" phenomenon occurred in some sampling sites, HCHs and Drins showed an increasing trend with increasing altitude, while DDTs showed an evident decrease with increasing altitude. The altitudinal distributions of OCPs were all consistent with previous findings in other mountainous regions. A primary fugacity analysis on OCPs soil-air exchange indicated that the profile may be secondary sources for HCHs and Endrin. As with Aldrin, Dieldrin, and DDTs, the profile may be both secondary sources and sinks.

  5. Crystal structure and X-ray photoemission spectroscopic study of A{sub 2}LaMO{sub 6} [A=Ba, Ca; M=Nb, Ta

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Alo, E-mail: alo_dutta@yahoo.com [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India); Saha, Sujoy [Department of Physics, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009 (India); Kumari, Premlata [Department of Chemistry, Government P.G. College, Lansdowne, Pauri-Garhwal 246139 (India); Sinha, T.P. [Department of Physics, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009 (India); Shannigrahi, Santiranjan [Institute of Materials Research and Engineering, Agency for Science Technology and Research, 3 Research Link, Singapore 117602 (Singapore)

    2015-09-15

    The X-ray photoemission spectroscopic (XPS) study of the double perovskite oxides A{sub 2}LaMO{sub 6} [A=Ba, Ca; M=Nb, Ta] synthesized by the solid-state reaction technique has been carried out to investigate the nature of the chemical state of the constituent ions and the bonding between them. The Rietveld refinement of the X-ray diffraction patterns suggests the monoclinic crystal structure of all the materials at room temperature. The negative and positive chemical shifts of the core level XPS spectrum of O-1s and Nb-3d{sub 3/2}/Ta-4f{sub 5/2} respectively suggest the covalent bonding between Nb/Ta cations and O ion. The change of the bonding strength between the anion and the cations from one material to another has been analyzed. The vibrational property of the materials is investigated using the room temperature Raman spectra. A large covalency of Ta-based compound than Nb compound is confirmed from the relative shifting of the Raman modes of the materials. - Graphical abstract: Crystal structure of two perovskite oxides CLN and CLT is investigated. XPS study confirms the two different co-ordination environments of Ca and covalent bonding between B-site cations and O-ion. - Highlights: • Ordered perovskite structure obtained by Rietveld refinement of XRD patterns. • Study of nature of chemical bonding by X-ray photoemission spectroscopy. • Opposite chemical shift of d-states of Nb/Ta with respect to O. • Covalent bonding between d-states of Nb/Ta and O. • Relative Raman shifts of CLN and CLT substantiate the more covalent character of Ta than Nb.

  6. Soybean salt tolerance 1 (GmST1 reduces ROS production, enhances ABA sensitivity and abiotic stress tolerance in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Shuxin eRen

    2016-04-01

    Full Text Available Abiotic stresses, including high soil salinity, significantly reduce crop production worldwide. Salt tolerance in plants is a complex trait and is regulated by multiple mechanisms. Understanding the mechanisms and dissecting the components on their regulatory pathways will provide new insights, leading to novel strategies for the improvement of salt tolerance in agricultural and economic crops of importance. Here we report that soybean salt tolerance 1, named GmST1, exhibited strong tolerance to salt stress in the Arabidopsis transgenic lines. The GmST1-overexpressed Arabidopsis also increased sensitivity to ABA and decreased production of reactive oxygen species (ROS under salt stress. In addition, GmST1 significantly improved drought tolerance in Arabidopsis transgenic lines. GmST1 belongs to a 3-prime part of Glyma.03g171600 gene in the current version of soybean genome sequence annotation. However, comparative RT-PCR analysis around Glyma.03g171600 genomic region confirmed that GmST1 might serve as an intact gene in soybean leaf tissues. Unlike Glyma.03g171600 which was not expressed in leaves, GmST1 was strongly induced by salt treatment in the leaf tissues. By promoter analysis, a TATA box was detected to be positioned close to GmST1 start codon and a putative ABRE and a DRE cis-acting elements were identified at about 1kb upstream of GmST1 gene. The data also indicated that GmST1-transgenic lines survived under drought stress and showed a significantly lower water loss than non-transgenic lines. In summary, our results suggest that overexpression of GmST1 significantly improves Arabidopsis tolerance to both salt and drought stresses and the gene may be a potential candidate for genetic engineering of salt- and drought-tolerant crops.

  7. Soybean Salt Tolerance 1 (GmST1) Reduces ROS Production, Enhances ABA Sensitivity, and Abiotic Stress Tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Ren, Shuxin; Lyle, Chimera; Jiang, Guo-Liang; Penumala, Abhishek

    2016-01-01

    Abiotic stresses, including high soil salinity, significantly reduce crop production worldwide. Salt tolerance in plants is a complex trait and is regulated by multiple mechanisms. Understanding the mechanisms and dissecting the components on their regulatory pathways will provide new insights, leading to novel strategies for the improvement of salt tolerance in agricultural and economic crops of importance. Here we report that soybean salt tolerance 1, named GmST1, exhibited strong tolerance to salt stress in the Arabidopsis transgenic lines. The GmST1-overexpressed Arabidopsis also increased sensitivity to ABA and decreased production of reactive oxygen species under salt stress. In addition, GmST1 significantly improved drought tolerance in Arabidopsis transgenic lines. GmST1 belongs to a 3-prime part of Glyma.03g171600 gene in the current version of soybean genome sequence annotation. However, comparative reverse transcription-polymerase chain reaction analysis around Glyma.03g171600 genomic region confirmed that GmST1 might serve as an intact gene in soybean leaf tissues. Unlike Glyma.03g171600 which was not expressed in leaves, GmST1 was strongly induced by salt treatment in the leaf tissues. By promoter analysis, a TATA box was detected to be positioned close to GmST1 start codon and a putative ABRE and a DRE cis-acting elements were identified at about 1 kb upstream of GmST1 gene. The data also indicated that GmST1-transgenic lines survived under drought stress and showed a significantly lower water loss than non-transgenic lines. In summary, our results suggest that overexpression of GmST1 significantly improves Arabidopsis tolerance to both salt and drought stresses and the gene may be a potential candidate for genetic engineering of salt- and drought-tolerant crops. PMID:27148284

  8. Structural and transport properties of A{sub 2}HoTaO{sub 6} [A=Ba, Sr, and Ca

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Alo, E-mail: alo_dutta@yahoo.com [Department of Physics, Bose Institute, 93/1, Acharya Prafulla Chandra Road, Kolkata 700009 (India); Sinha, T.P. [Department of Physics, Bose Institute, 93/1, Acharya Prafulla Chandra Road, Kolkata 700009 (India); Das, Dipankar [UGC-DAE Consortium for Scientific Research, Kolkata Centre, III/LB-8, Salt Lake, Kolkata 700098 (India)

    2014-06-01

    Double perovskite oxides A{sub 2}HoTaO{sub 6} [A=Ba, Sr, and Ca] are synthesized by a solid state reaction technique. The Rietveld refinement of the X-ray diffraction pattern shows that Ba{sub 2}HoTaO{sub 6} crystalizes in cubic Fm3m symmetry whereas Sr{sub 2}HoTaO{sub 6} and Ca{sub 2}HoTaO{sub 6} adopt the monoclinic P2{sub 1}/n symmetry. The field cooled and zero field cooled magnetic susceptibilities of the materials are measured in the temperature range from 5 K to 300 K. The temperature dependence of inverse magnetic susceptibility shows the antiferromagnetic behavior of these systems. The dielectric relaxation of the samples is investigated by the Cole–Cole model in the frequency range from 50 Hz to 1 MHz and in the temperature range from 303 K to 673 K. The frequency dependent conductivity spectra follow the power law. The scaling behavior of the imaginary part of the impedance spectra suggests that the relaxation shows the same mechanism at various temperatures. - Highlights: • The Rietveld refinement indicates that B{sub 2}HoTaO{sub 6} has cubic Fm3m symmetry. • Sr{sub 2}HoTaO{sub 6} and Ca{sub 2}HoTaO{sub 6} adopt the monoclinic P2{sub 1}/n crystal symmetry. • The temperature dependence of inverse magnetic susceptibilities follows the Curie–Wiess law. • The superexchange interaction between the Ho ions leads to antiferromagnetism in these systems. • Dielectric relaxation mechanism is explained using the Cole–Cole model.

  9. 钙和ABA在番茄果实乙烯生物合成中的相互作用%Relationship Between Calcium and ABA in Ethylene Synthesis in Tomato Fruit

    Institute of Scientific and Technical Information of China (English)

    朱本忠; 魏绍冲; 罗云波

    2003-01-01

    研究了钙和ABA对不同成熟阶段和不同成熟模式番茄(Lycopersicon esculentum cv.Lichun)果实乙烯生成的影响,分析两者在乙烯生物合成系统中的相互作用.普通番茄绿熟果实组织圆片在用100μmol/LABA和100mmol/L钙处理后,乙烯生成均很快增加.当用这两种试剂同时处理番茄果实圆片时,乙烯生成增加量明显比单一处理增加量大,表明两者在对绿熟番茄果实乙烯生成的影响中有协同作用关系.钙离子鳌合剂EGTA(乙二醇双乙胺醚-N,N'-四乙酸)对乙烯生成有抑制作用,用ABA和EGTA同时处理番茄圆片时,乙烯的生成量比EGTA单一处理的生成量要高.当用这些试剂处理未成熟番茄果实则产生不同的效果,ABA明显抑制乙烯生成,而钙却依然促进乙烯的生物合成,ABA和钙同时处理果实时,乙烯生成量介于二者单一处理之间,表明ABA和钙在未成熟番茄果实乙烯生成中表现出相互抑制作用.在转反义ACS番茄中,ABA和钙抑制未成熟果实的乙烯生成,而都促进了绿熟果实的乙烯生成.这表明ABA和钙在番茄果实不同成熟阶段和不同成熟模式的乙烯生物合成过程中有着不同的相互作用关系.%The influence of calcium and ABA respectively on the ethylene biosynthesis was investigated in difterent stages andpattems of tomato (Lycopersicon esculentum cv. Lichun) fruit to analyze the relationship between calcium and ABA in relation toethylene biosynthesis system. The ethylene production of discs excised from mature green tomato fruits increased rapidly with 100μ mol/LABA or 100 mmol/L calcium treatment, and the increasement of the two treatments at the same time was more than that ofsingle chemical application, which suggested that these two chemicals would play their roles synergistically in the ethylene synthesisof mature green tomato fruits. It was also founded that application of the calcium chelator EGTA ( ethyleneglycol

  10. A STRESS-RESPONSIVE NAC1-regulated protein phosphatase gene rice protein phosphatase18 modulates drought and oxidative stress tolerance through abscisic acid-independent reactive oxygen species scavenging in rice.

    Science.gov (United States)

    You, Jun; Zong, Wei; Hu, Honghong; Li, Xianghua; Xiao, Jinghua; Xiong, Lizhong

    2014-12-01

    Plants respond to abiotic stresses through a complexity of signaling pathways, and the dephosphorylation mediated by protein phosphatase (PP) is an important event in this process. We identified a rice (Oryza sativa) PP2C gene, OsPP18, as a STRESS-RESPONSIVE NAC1 (SNAC1)-regulated downstream gene. The ospp18 mutant was more sensitive than wild-type plants to drought stress at both the seedling and panicle development stages. Rice plants with OsPP18 suppressed through artificial microRNA were also hypersensitive to drought stress. Microarray analysis of the mutant revealed that genes encoding reactive oxygen species (ROS) scavenging enzymes were down-regulated in the ospp18 mutant, and the mutant exhibited reduced activities of ROS scavenging enzymes and increased sensitivity to oxidative stresses. Overexpression of OsPP18 in rice led to enhanced osmotic and oxidative stress tolerance. The expression of OsPP18 was induced by drought stress but not induced by abscisic acid (ABA). Although OsPP18 is a typical PP2C with enzymatic activity, it did not interact with SNF1-RELATED PROTEIN KINASE2 protein kinases, which function in ABA signaling. Meanwhile, the expression of ABA-responsive genes was not affected in the ospp18 mutant, and the ABA sensitivities of the ospp18 mutant and OsPP18-overexpressing plants were also not altered. Together, these findings suggest that OsPP18 is a unique PP2C gene that is regulated by SNAC1 and confers drought and oxidative stress tolerance by regulating ROS homeostasis through ABA-independent pathways.

  11. Auxin: a major player in the shoot-to-root regulation of root Fe-stress physiological responses to Fe deficiency in cucumber plants.

    Science.gov (United States)

    Bacaicoa, Eva; Mora, Verónica; Zamarreño, Angel María; Fuentes, Marta; Casanova, Esther; García-Mina, José María

    2011-05-01

    The aim of this study was to investigate the effects of IAA and ABA in the shoot-to-root regulation of the expression of the main Fe-stress physiological root responses in cucumber plants subjected to shoot Fe functional deficiency. Changes in the expression of the genes CsFRO1, CsIRT1, CsHA1 and CsHA2 (coding for Fe(III)-chelate reductase (FCR), the Fe(II) transporter and H+-ATPase, respectively) and in the enzyme activity of FCR and the acidification capacity were measured. We studied first the ability of exogenous applications of IAA and ABA to induce these Fe-stress root responses in plants grown in Fe-sufficient conditions. The results showed that IAA was able to activate these responses at the transcriptional and functional levels, whereas the results with ABA were less conclusive. Thereafter, we explored the role of IAA in plants with or without shoot Fe functional deficiency in the presence of two types of IAA inhibitors, affecting either IAA polar transport (TIBA) or IAA functionality (PCIB). The results showed that IAA is involved in the regulation at the transcriptional and functional levels of both Fe root acquisition (FCR, Fe(II) transport) and rhizosphere acidification (H+-ATPase), although through different, and probably complementary, mechanisms. These results suggest that IAA is involved in the shoot-to-root regulation of the expression of Fe-stress physiological root responses. PMID:21411331

  12. Arabidopsis decuple mutant reveals the importance of SnRK2 kinases in osmotic stress responses in vivo

    KAUST Repository

    Fujii, Hiroaki

    2011-01-10

    Osmotic stress associated with drought or salinity is a major factor that limits plant productivity. Protein kinases in the SNF1-related protein kinase 2 (SnRK2) family are activated by osmotic stress, suggesting that the kinases are involved in osmotic stress signaling. However, due to functional redundancy, their contribution to osmotic stress responses remained unclear. In this report, we constructed an Arabidopsis line carrying mutations in all 10 members of the SnRK2 family. The decuple mutant snrk2.1/2/3/4/5/6/7/8/9/10 grew poorly under hyperosmotic stress conditions but was similar to the wild type in culture media in the absence of osmotic stress. The mutant was also defective in gene regulation and the accumulation of abscisic acid (ABA), proline, and inositol 1,4,5-trisphosphate under osmotic stress. In addition, analysis of mutants defective in the ABA-activated SnRK2s (snrk2.2/3/6) and mutants defective in the rest of the SnRK2s (snrk2.1/4/5/7/8/9/10) revealed that SnRK2s are a merging point of ABA-dependent and -independent pathways for osmotic stress responses. These results demonstrate critical functions of the SnRK2s in mediating osmotic stress signaling and tolerance.

  13. How plants handle multiple stresses: hormonal interactions underlying responses to abiotic stress and insect herbivory.

    Science.gov (United States)

    Nguyen, Duy; Rieu, Ivo; Mariani, Celestina; van Dam, Nicole M

    2016-08-01

    Adaptive plant responses to specific abiotic stresses or biotic agents are fine-tuned by a network of hormonal signaling cascades, including abscisic acid (ABA), ethylene, jasmonic acid (JA) and salicylic acid. Moreover, hormonal cross-talk modulates plant responses to abiotic stresses and defenses against insect herbivores when they occur simultaneously. How such interactions affect plant responses under multiple stresses, however, is less understood, even though this may frequently occur in natural environments. Here, we review our current knowledge on how hormonal signaling regulates abiotic stress responses and defenses against insects, and discuss the few recent studies that attempted to dissect hormonal interactions occurring under simultaneous abiotic stress and herbivory. Based on this we hypothesize that drought stress enhances insect resistance due to synergistic interactions between JA and ABA signaling. Responses to flooding or waterlogging involve ethylene signaling, which likely reduces plant resistance to chewing herbivores due to its negative cross-talk with JA. However, the outcome of interactions between biotic and abiotic stress signaling is often plant and/or insect species-dependent and cannot simply be predicted based on general knowledge on the involvement of signaling pathways in single stress responses. More experimental data on non-model plant and insect species are needed to reveal general patterns and better understand the molecular mechanisms allowing plants to optimize their responses in complex environments. PMID:27095445

  14. Hydrogen Sulfide Mediates ABA-induced Stomatal Closure of Vicia faba L.%H2S介导ABA诱导蚕豆气孔运动的生理机制研究

    Institute of Scientific and Technical Information of China (English)

    刘菁; 侯智慧; 赵方贵; 刘新

    2011-01-01

    Through pharmacological combined with spectrophotography to study the effects of ABA and ABA with inhibitors of H2S synthesis on stomatal closure of Vicia faba L., H2S generation and L-/D-cysteine desulfhydrase (pyridoxalphosphate dependent enzymes) activity.The results showed that AOA and NH2OH, inhibitors of pyridoxal-5 ‘-phosphate-dependent enzymes, C3H3KO3 + NH3, products of L-/D-cysteine desulfhydrase all inhibited ABA- induced stomatal closure of Vicia faba L.obviously under light condition.Treatment with ABA induced H2S generation and increased L-/D-cysteine desulfhydrase activity.AOA,NH2OH,C3H3KO3+NH3 reduced H2S generation induced by ABA and the activity increase of L-/D-cysteine desulfhydrase.Those results suggested that ABA enhanced the activity of L-/D-cysteine desulfhydrase,inducing the accumulation of H2S via L-/D-cysteine resolving, and finally induced stomatal closure of Vicia faba L..%以蚕豆为实验材料,利用药理学实验和分光光度法,研究了ABA处理及ABA与H2S合成抑制剂共处理对蚕豆气孔运动的影响,以及体内H2S水平、H2S合成酶L-/D-半胱氨酸脱巯基酶(磷酸吡哆盐依赖性酶)活性变化.结果表明:(1)光下H2S的合成抑制剂羧甲氧基胺半盐酸盐(AOA)、羟氨(NH2OH)、L-/D-半胱氨酸脱巯基酶分解产物C3H3KO3+NH3均明显抑制ABA诱导的蚕豆气孔关闭;(2)外源ABA能够明显提高叶片的H2S水平及L-/D-半胱氨酸脱巯基酶活性;(3)AOA、NH2OH、C3H3KO3和NH3均可以逆转ABA所引起的H2S水平及L-/D-半胱氨酸脱巯基酶活性的升高.研究发现,ABA可通过增强L-/D-半胱氨酸脱巯基酶活性,促进L-/D-半胱氨酸分解生成H2S,进而诱导蚕豆气孔关闭.

  15. On the Current Issues and Reform of Preschool Education Teachers in the Rural Areas of Aba Prefecture%阿坝州农村学前教育师资存在的问题及改革探析

    Institute of Scientific and Technical Information of China (English)

    梁建东; 梁涛; 李娟

    2011-01-01

    学前教育是国家和社会稳定和发展的重要基础,也是提高国民素质的重要基础工程。而学前教育中师资水平的高低直接决定着学前教育质量的好坏,阿坝州农村学前教育不仅师资队伍不稳定,还严重影响着阿坝州教育的健康发展。本文将分析阿坝州农村学前教育师资存在的问题与如何有效建设阿坝州学前教育师资队伍等方面展开探析,旨在为提高阿坝州农村学前教育师资队伍水平和促进全州学前教育的健康发展提供可行性建议。%Preschool education is an important foundation for the development of country and social stability as well as for the improvement of the overall quality of the whole nation. And the competence of teachers for preschool education has a great impact on teaching quality. Currently, the worrisome situation of teachers for preschool education in the rural areas of Aba prefecture not only leads to the shortage of teachers, but also prevents the full and healthy development of the education in Aba prefecture.In this article, the author would like to talk about the current situation of the preschool education teachers in the rural areas of Aba prefecture and how to effectively strengthen the teacher troops,on the purpose of enhancing the teaching level and providing some feasible advice on the development of preschool education in the whole prefecture.

  16. Aspectos bioecológicos de Puma concolor (Linnaeus, 1771), Leopardus pardalis (Linnaeus, 1758) e Leopardus tigrinus (Schreber, 1775) na reserva natural Salto Morato, Guaraqueçaba, Paraná, Brasil

    OpenAIRE

    Vidolin, Gisley Paula

    2013-01-01

    De janeiro de 2000 a agosto de 2002, foi realizado um estudo com Puma concolor (puma), Leopardus pardaus (jaguatirica) e Leopardus tigrinus (gato-do-mato-pequeno) na Reserva Natural Salto Morato, Guaraqueçaba, com os objetivos de determinar e caracterizar as áreas utilizadas pelas espécies; descrever a sua dieta; verificar se há correlação da freqüência dos itens encontrados nas fezes, em função de sua disponibilidade na natureza (médio e grandes mamíferos); gerar informações sobre os tipos d...

  17. Transcriptome Changes in Hirschfeldia incana in Response to Lead Exposure.

    Science.gov (United States)

    Auguy, Florence; Fahr, Mouna; Moulin, Patricia; El Mzibri, Mohamed; Smouni, Abdelaziz; Filali-Maltouf, Abdelkarim; Béna, Gilles; Doumas, Patrick

    2015-01-01

    Hirschfeldia incana, a pseudometallophyte belonging to the Brassicaceae family and widespread in the Mediterranean region, was selected for its ability to grow on soils contaminated by lead (Pb). The global comparison of gene expression using microarrays between a plant susceptible to Pb (Arabidopsis thaliana) and a Pb tolerant plant (H. incana) enabled the identification of a set of specific genes expressed in response to lead exposure. Three groups of genes were particularly over-represented by the Pb exposure in the biological processes categorized as photosynthesis, cell wall, and metal handling. Each of these gene groups was shown to be directly involved in tolerance or in protection mechanisms to the phytotoxicity associated with Pb. Among these genes, we demonstrated that MT2b, a metallothionein gene, was involved in lead accumulation, confirming the important role of metallothioneins in the accumulation and the distribution of Pb in leaves. On the other hand, several genes involved in biosynthesis of ABA were shown to be up-regulated in the roots and shoots of H. incana treated with Pb, suggesting that ABA-mediated signaling is a possible mechanism in response to Pb treatment in H. incana. This latest finding is an important research direction for future studies.

  18. Transcriptome changes in Hirschfeldia incana in response to lead exposure

    Directory of Open Access Journals (Sweden)

    Florence eAuguy

    2016-01-01

    Full Text Available Hirschfeldia incana, a pseudometallophyte belonging to the Brassicaceae family and widespread in the Mediterranean region, was selected for its ability to grow on soils contaminated by lead (Pb .The global comparison of gene expression using microarrays between a plant susceptible to Pb (Arabidopsis thaliana and a Pb tolerant plant (Hirschfeldia incana enabled the identification of a set of specific genes expressed in response to lead exposure. Three groups of genes were particularly over-represented by the Pb exposure in the biological processes categorized as photosynthesis, cell wall and metal handling. Each of these gene groups was shown to be directly involved in tolerance or in protection mechanisms to the phytotoxicity associated with Pb. Among these genes, we demonstrated that MT2b, a metallothionein gene, was involved in lead accumulation, confirming the important role of metallothioneins in the accumulation and the distribution of Pb in leaves. On the other hand, several genes involved in biosynthesis of ABA were shown to be up-regulated in the roots and shoots of H. incana treated with Pb, suggesting that ABA-mediated signaling is a possible mechanism in response to Pb treatment in H. incana. This latest finding is an important research direction for future studies.

  19. Overexpression of a Stress-Responsive NAC Transcription Factor Gene ONAC022 Improves Drought and Salt Tolerance in Rice.

    Science.gov (United States)

    Hong, Yongbo; Zhang, Huijuan; Huang, Lei; Li, Dayong; Song, Fengming

    2016-01-01

    The NAC transcription factors play critical roles in regulating stress responses in plants. However, the functions for many of the NAC family members in rice are yet to be identified. In the present study, a novel stress-responsive rice NAC gene, ONAC022, was identified. Expression of ONAC022 was induced by drought, high salinity, and abscisic acid (ABA). The ONAC022 protein was found to bind specifically to a canonical NAC recognition cis-element sequence and showed transactivation activity at its C-terminus in yeast. The ONAC022 protein was localized to nucleus when transiently expressed in Nicotiana benthamiana. Three independent transgenic rice lines with overexpression of ONAC022 were generated and used to explore the function of ONAC022 in drought and salt stress tolerance. Under drought stress condition in greenhouse, soil-grown ONAC022-overexpressing (N22oe) transgenic rice plants showed an increased drought tolerance, leading to higher survival ratios and better growth than wild-type (WT) plants. When grown hydroponically in Hogland solution supplemented with 150 mM NaCl, the N22oe plants displayed an enhanced salt tolerance and accumulated less Na(+) in roots and shoots as compared to WT plants. Under drought stress condition, the N22oe plants exhibited decreased rates of water loss and transpiration, reduced percentage of open stomata and increased contents of proline and soluble sugars. However, the N22oe lines showed increased sensitivity to exogenous ABA at seed germination and seedling growth stages but contained higher level of endogenous ABA. Expression of some ABA biosynthetic genes (OsNCEDs and OsPSY), signaling and regulatory genes (OsPP2C02, OsPP2C49, OsPP2C68, OsbZIP23, OsAP37, OsDREB2a, and OsMYB2), and late stress-responsive genes (OsRAB21, OsLEA3, and OsP5CS1) was upregulated in N22oe plants. Our data demonstrate that ONAC022 functions as a stress-responsive NAC with transcriptional activator activity and plays a positive role in drought

  20. Overexpression of a stress-responsive NAC transcription factor gene ONAC022 improves drought and salt tolerance in rice

    Directory of Open Access Journals (Sweden)

    Yongbo eHong

    2016-01-01

    Full Text Available The NAC transcription factors play critical roles in regulating stress responses in plants. However, the functions for many of the NAC family members in rice are yet to be identified. In the present study, a novel stress-responsive rice NAC gene, ONAC022, was identified. Expression of ONAC022 was induced by drought, high salinity and abscisic acid (ABA. The ONAC022 protein was found to bind specifically to a canonical NAC recognition cis-element sequence and showed transactivation activity at its C-terminus in yeast. The ONAC022 protein was localized to nucleus when transiently expressed in Nicotiana benthamiana. Three independent transgenic rice lines with overexpression of ONAC022 were generated and used to explore the function of ONAC022 in drought and salt stress tolerance. Under drought stress condition in greenhouse, soil-grown ONAC022-overexpressing (N22oe transgenic rice plants showed an increased drought tolerance, leading to higher survival ratios and better growth than wild type plants. When grown hydroponically in Hogland solution supplemented with 150 mM NaCl, the N22oe plants displayed an enhanced salt tolerance and accumulated less Na+ in roots and shoots as compared to the wild type plants. Under drought stress condition, the N22oe plants exhibited decreased rates of water loss and transpiration, reduced percentage of open stomata and increased contents of proline and soluble sugars. However, the N22oe lines showed increased sensitivity to exogenous ABA at seed germination and seedling growth stages but contained higher level of endogenous ABA. Expression of some ABA biosynthetic genes (OsNCEDs and OsPSY, signaling and regulatory genes (OsPP2C02, OsPP2C49, OsPP2C68, OsbZIP23, OsAP37, OsDREB2a and OsMYB2 and late stress-responsive genes (OsRAB21, OsLEA3 and OsP5CS1 was upregulated in the N22oe plants. Our data demonstrate that ONAC022 functions as a stress-responsive NAC with transcriptional activator activity and plays a positive

  1. Four Arabidopsis AREB/ABF transcription factors function predominantly in gene expression downstream of SnRK2 kinases in abscisic acid signalling in response to osmotic stress.

    Science.gov (United States)

    Yoshida, Takuya; Fujita, Yasunari; Maruyama, Kyonoshin; Mogami, Junro; Todaka, Daisuke; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2015-01-01

    Under osmotic stress conditions such as drought and high salinity, the plant hormone abscisic acid (ABA) plays important roles in stress-responsive gene expression mainly through three bZIP transcription factors, AREB1/ABF2, AREB2/ABF4 and ABF3, which are activated by SNF1-related kinase 2s (SnRK2s) such as SRK2D/SnRK2.2, SRK2E/SnRK2.6 and SRK2I/SnRK2.3 (SRK2D/E/I). However, since the three AREB/ABFs are crucial, but not exclusive, for the SnRK2-mediated gene expression, transcriptional pathways governed by SRK2D/E/I are not fully understood. Here, we show that a bZIP transcription factor, ABF1, is a functional homolog of AREB1, AREB2 and ABF3 in ABA-dependent gene expression in Arabidopsis. Despite lower expression levels of ABF1 than those of the three AREB/ABFs, the areb1 areb2 abf3 abf1 mutant plants displayed increased sensitivity to drought and decreased sensitivity to ABA in primary root growth compared with the areb1 areb2 abf3 mutant. Genome-wide transcriptome analyses revealed that expression of downstream genes of SRK2D/E/I, which include many genes functioning in osmotic stress responses and tolerance such as transcription factors and LEA proteins, was mostly impaired in the quadruple mutant. Thus, these results indicate that the four AREB/ABFs are the predominant transcription factors downstream of SRK2D/E/I in ABA signalling in response to osmotic stress during vegetative growth.

  2. Expression profiles of 12 late embryogenesis abundant protein genes from Tamarix hispida in response to abiotic stress.

    Science.gov (United States)

    Gao, Caiqiu; Liu, Yali; Wang, Chao; Zhang, Kaimin; Wang, Yucheng

    2014-01-01

    Twelve embryogenesis abundant protein (LEA) genes (named ThLEA-1 to -12) were cloned from Tamarix hispida. The expression profiles of these genes in response to NaCl, PEG, and abscisic acid (ABA) in roots, stems, and leaves of T. hispida were assessed using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). These ThLEAs all showed tissue-specific expression patterns in roots, stems, and leaves under normal growth conditions. However, they shared a high similar expression patterns in the roots, stems, and leaves when exposed to NaCl and PEG stress. Furthermore, ThLEA-1, -2, -3, -4, and -11 were induced by NaCl and PEG, but ThLEA-5, -6, -8, -10, and -12 were downregulated by salt and drought stresses. Under ABA treatment, some ThLEA genes, such as ThLEA-1, -2, and -3, were only slightly differentially expressed in roots, stems, and leaves, indicating that they may be involved in the ABA-independent signaling pathway. These findings provide a basis for the elucidation of the function of LEA genes in future work. PMID:25133264

  3. A no hydrotropic response root mutant that responds positively to gravitropism in Arabidopsis.

    Science.gov (United States)

    Eapen, Delfeena; Barroso, María Luisa; Campos, María Eugenia; Ponce, Georgina; Corkidi, Gabriel; Dubrovsky, Joseph G; Cassab, Gladys I

    2003-02-01

    For most plants survival depends upon the capacity of root tips to sense and move towards water and other nutrients in the soil. Because land plants cannot escape environmental stress they use developmental solutions to remodel themselves in order to better adapt to the new conditions. The primary site for perception of underground signals is the root cap (RC). Plant roots have positive hydrotropic response and modify their growth direction in search of water. Using a screening system with a water potential gradient, we isolated a no hydrotropic response (nhr) semi-dominant mutant of Arabidopsis that continued to grow downwardly into the medium with the lowest water potential contrary to the positive hydrotropic and negative gravitropic response seen in wild type-roots. The lack of hydrotropic response of nhr1 roots was confirmed in a system with a gradient in air moisture. The root gravitropic response of nhr1 seedlings was significantly faster in comparison with those of wild type. The frequency of the waving pattern in nhr1 roots was increased compared to those of wild type. nhr1 seedlings had abnormal root cap morphogenesis and reduced root growth sensitivity to abscisic acid (ABA) and the polar auxin transport inhibitor N-(1-naphtyl)phtalamic acid (NPA). These results showed that hydrotropism is amenable to genetic analysis and that an ABA signaling pathway participates in sensing water potential gradients through the root cap.

  4. Structure, function and networks of transcription factors involved in abiotic stress responses

    DEFF Research Database (Denmark)

    Lindemose, Søren; O'Shea, Charlotte; Jensen, Michael Krogh;

    2013-01-01

    Transcription factors (TFs) are master regulators of abiotic stress responses in plants. This review focuses on TFs from seven major TF families, known to play functional roles in response to abiotic stresses, including drought, high salinity, high osmolarity, temperature extremes and the phytoho......Transcription factors (TFs) are master regulators of abiotic stress responses in plants. This review focuses on TFs from seven major TF families, known to play functional roles in response to abiotic stresses, including drought, high salinity, high osmolarity, temperature extremes...... and the phytohormone ABA. Although ectopic expression of several TFs has improved abiotic stress tolerance in plants, fine-tuning of TF expression and protein levels remains a challenge to avoid crop yield loss. To further our understanding of TFs in abiotic stress responses, emerging gene regulatory networks based...... on TFs and their direct targets genes are presented. These revealed components shared between ABA-dependent and independent signaling as well as abiotic and biotic stress signaling. Protein structure analysis suggested that TFs hubs of large interactomes have extended regions with protein intrinsic...

  5. Functional annotation of the transcriptome of Sorghum bicolor in response to osmotic stress and abscisic acid

    Directory of Open Access Journals (Sweden)

    Kumari Sunita

    2011-10-01

    Full Text Available Abstract Background Higher plants exhibit remarkable phenotypic plasticity allowing them to adapt to an extensive range of environmental conditions. Sorghum is a cereal crop that exhibits exceptional tolerance to adverse conditions, in particular, water-limiting environments. This study utilized next generation sequencing (NGS technology to examine the transcriptome of sorghum plants challenged with osmotic stress and exogenous abscisic acid (ABA in order to elucidate genes and gene networks that contribute to sorghum's tolerance to water-limiting environments with a long-term aim of developing strategies to improve plant productivity under drought. Results RNA-Seq results revealed transcriptional activity of 28,335 unique genes from sorghum root and shoot tissues subjected to polyethylene glycol (PEG-induced osmotic stress or exogenous ABA. Differential gene expression analyses in response to osmotic stress and ABA revealed a strong interplay among various metabolic pathways including abscisic acid and 13-lipoxygenase, salicylic acid, jasmonic acid, and plant defense pathways. Transcription factor analysis indicated that groups of genes may be co-regulated by similar regulatory sequences to which the expressed transcription factors bind. We successfully exploited the data presented here in conjunction with published transcriptome analyses for rice, maize, and Arabidopsis to discover more than 50 differentially expressed, drought-responsive gene orthologs for which no function had been previously ascribed. Conclusions The present study provides an initial assemblage of sorghum genes and gene networks regulated by osmotic stress and hormonal treatment. We are providing an RNA-Seq data set and an initial collection of transcription factors, which offer a preliminary look into the cascade of global gene expression patterns that arise in a drought tolerant crop subjected to abiotic stress. These resources will allow scientists to query gene

  6. Responses of In vitro-Grown Plantlets (Vitis vinifera) to Grapevine leafroll-Associated Virus-3 and PEG-Induced Drought Stress

    Science.gov (United States)

    Cui, Zhen-Hua; Bi, Wen-Lu; Hao, Xin-Yi; Xu, Yan; Li, Peng-Min; Walker, M. Andrew; Wang, Qiao-Chun

    2016-01-01

    Stresses caused by viral diseases and drought have long threatened sustainable production of grapevine. These two stresses frequently occur simultaneously in many of grapevine growing regions of the world. We studied responses of in vitro-grown plantlets (Vitis vinifera) to Grapevine leafroll associated virus-3 (GLRaV-3) and PEG-induced drought stress. Results showed that stress induced by either virus infection or drought had negative effects on vegetative growth, caused significant decreases and increases in total soluble protein and free proline, respectively, induced obvious cell membrane damage and cell death, and markedly increased accumulations of O2·- and H2O2. Co-stress by virus and drought had much severer effects than single stress on the said parameters. Virus infection alone did not cause significant alternations in activities of POD, ROS, and SOD, and contents of MDA, which, however, markedly increased in the plantlets when grown under single drought stress and co-stress by the virus and drought. Levels of ABA increased, while those of IAA decreased in the plantlets stressed by virus infection or drought. Simultaneous stresses by the virus and drought had co-effects on the levels of ABA and IAA. Up-regulation of expressions of ABA biosynthesis genes and down-regulation of expressions of IAA biosynthesis genes were responsible for the alternations of ABA and IAA levels induced by either the virus infection or drought stress and co-stress by them. Experimental strategies established in the present study using in vitro system facilitate investigations on ‘pure’ biotic and abiotic stress on plants. The results obtained here provide new insights into adverse effects of stress induced by virus and drought, in single and particularly their combination, on plants, and allow us to re-orientate agricultural managements toward sustainable development of the agriculture. PMID:27313542

  7. Physiological response of riparian plants to watering in hyper-arid areas of Tarim River,China

    Institute of Scientific and Technical Information of China (English)

    RUAN Xiao; WANG Qiang; CHEN Yaning; LI Weihong

    2007-01-01

    The physiological responses and adaptive strategies of Populus euphratica Oliv.(arbor species),Tamarix ramosissima Ldb.(bush species),and Apocynum venetum L.(herb species)to variations in water and salinity stress were studied in the hyper-arid environment of the Tarim River in China.The groundwater table,the saline content of the groundwater,as well as the content of free proline,soluble sugars,plant endogenous hormones (abscisic acid (ABA),and cytokinins (CTK))of the leaves of the three species were monitored and analyzed at the lower reaches of the Tarim River in the study area where five transects were fixed at 100 m intervals along a vertical sampling line before and after water release.Saline stress dramatically increased soluble sugar concentration of the three species.Differences in sugar accumulation were determined among the species at different transects.The free proline concentration of the leaves of T.ramosissima and P.euphratica showed a proportional decrease with various degrees of elevation of the groundwater table after water release.There was a least correlation between the soluble sugars and proline stimulation in T.ramosissima.It was strongly suggested that T.ramosissima developed a different strategy to accumulate organic solutes to adapt to the stress environment.The soluble sugars and proline accumulation responded to the changes of groundwater table independently:the former occurred under salt stress,whereas the latter was more significant under drought stress.The concentration and the increase in concentration of ABA and CTK involved in stress resistance of the three species were also determined.This increase in the hormone concentration in P.euphratica was different from that of the other two species.Expressed as a function of increase of ABA concentration in leaves,A.venetum and T.ramosissima showed a different solute accumulation in response to groundwater table.There was a significant correlation between ABA accumulation and A [proline

  8. Identification and characterization of a salt tolerance-responsive gene( AtGRP9) of Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Soil salinity is one of the important limiting factors for plant growth and development. A cDNA clone encoding a glycine-rich protein (designated AtGRP9) was identified from Arabidopsis by functional expression of the plant cDNA library in the fission yeast S. pombe. Yeast cells overexpressing AtGRP9 displayed significantly enhanced salt tolerance. Northern analysis showed that expression of AtGRP9 in Arabidopsis was induced by NaCl and plant hormone abscisic acid (ABA). These results suggest that AtGRP9 may be involved in the salt stress response in Arabidopsis.

  9. Combinatorial Signal Integration by APETALA2/Ethylene Response Factor (ERF-Transcription Factors and the Involvement of AP2-2 in Starvation Response

    Directory of Open Access Journals (Sweden)

    Karl-Josef Dietz

    2012-05-01

    Full Text Available Transcription factors of the APETALA 2/Ethylene Response Factor (AP2/ERF-family have been implicated in diverse processes during development, stress acclimation and retrograde signaling. Fifty-three leaf-expressed AP2/ERFs were screened for their transcriptional response to abscisic acid (ABA, 3-(3,4-dichlorophenyl-1,1-dimethylurea (DCMU, methylviologen (MV, sucrose and high or low light, respectively, and revealed high reactivity to these effectors. Six of them (AP2-2, ARF14, CEJ1, ERF8, ERF11, RAP2.5 were selected for combinatorial response analysis to ABA, DCMU and high light. Additive, synergistic and antagonistic effects demonstrated that these transcription factors are components of multiple signaling pathways. AP2-2 (At1g79700 was subjected to an in depth study. AP2-2 transcripts were high under conditions linked to limited carbohydrate availability and stress and down-regulated in extended light phase, high light or in the presence of sugar. ap2-2 knock out plants had unchanged metabolite profiles and transcript levels of co-expressed genes in extended darkness. However, ap2-2 revealed more efficient germination and faster early growth under high sugar, osmotic or salinity stress, but the difference was abolished in the absence of sugar or during subsequent growth. It is suggested that AP2-2 is involved in mediating starvation-related and hormonal signals.

  10. AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.

    Directory of Open Access Journals (Sweden)

    Dario A Breitel

    2016-03-01

    Full Text Available The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A, a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA. Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1 protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process.

  11. Influences of ABA, Sucrose and Silicon on Enhancing Shade Tolerance of Two Lawn Grasses%脱落酸、蔗糖和硅对高羊茅和草地早熟禾耐荫性的影响

    Institute of Scientific and Technical Information of China (English)

    李丽群; 陶莲; 周禾

    2012-01-01

    Lawn grasses play an increasing role in urban greening and environment conservation.Shade tolerance is a particularly serious problem for lawn grasses resulting from tall city buildings.Tall fescue and Kentucky bluegrass are two main cool-season lawn grasses.The technology of improving shade tolerance of lawn grasses are discussed in this paper.Both lawn grasses under 57% shade stress are treated using ABA,sucrose and silicon.Each treatment includes four difference concentrations (ABA: 0, 0.02, 0.06, 0.10 mmol · L-1 , sucrose: 0, 600, 800, 1000 mg · L-1, silicon: 0, 0.50, 1.00, 1.50 mmol · L-1).Results indicate that ABA is not suitable for enhancing shade tolerance of either lawn grasses, but both sucrose and silicon can promote shade tolerance for both lawn grasses.The best concentration of sucrose is 800 mg · L-1 for tall fescue and 600 mg · L-1 for Kentucky bluegrass.The best concentration of silicon is 0.50 mmol · L-1 for tall fescue and 1.50 mmol · L-1 for Kentucky bluegrass.%为探索外源物质对草坪革耐荫性的作用效果及其最佳浓度,在57%遮荫胁迫下,选用脱落酸(ABA) (0,0.02,0.06和0.10mmol·L-1)、蔗糖(0,600,800和1000mg·L-1)和硅酸钠(0,0.50,1.00和1.50 mmol·L-1)对盆栽高羊茅(Festuca arundinacea)和草地早熟禾(Poa pretensis)进行处理.结果表明:各浓度ABA对提高2种草坪草耐荫性没有效果,反而加重胁迫,明显抑制植株的生长,严重影响草坪外观质量;适宜浓度的蔗糖和硅酸钠能不同程度的促进2种草坪草的生长,提高其耐荫性;800 mg· L-1蔗糖和0.50 mmol·L-1硅酸钠对高羊茅处理效果最佳,600mg·L-1蔗糖和1.50 mmol·L-1硅酸钠对草地早熟禾处理效果最佳.

  12. 水分胁迫下离体烟叶中脂氧合酶活性与脱落酸积累的关系%Relationship between LOX Activity and ABA Accumulation in Tobacco Leave under Water Stress

    Institute of Scientific and Technical Information of China (English)

    宫长荣; 李艳梅; 张莉

    2002-01-01

    采用河南农业大学设计的电热式温湿度自控烤烟箱,研究了水分胁迫离体烟叶中脂氧合酶(LOX)活性与脱落酸(ABA)积累的关系.结果表明,水分胁迫下ABA积累的同时,LOX活性也上升,二者相关性达5%的显著水平;LOX专-抑制剂去甲二氢菊木酸(NDGA)在抑制LOX活性的同时也阻断了ABA的积累;无细胞体系加入LOX可直接引起ABA的积累.这表明LOX很可能是生物合成及胁迫诱导ABA积累的一个关键酶.

  13. ABA和SA对于提高植物抗旱及抗盐性的研究进展%Progress in ABA and SA Improving Plant Drought Resistance and Salt Resistance

    Institute of Scientific and Technical Information of China (English)

    任菲; 张荣佳; 陈强; 白艳波; 黄菲; 李雪梅

    2012-01-01

    植物受到环境胁迫后体内会产生活性氧自由基等有害物质,破坏质膜透性,导致植物生长受到抑制.经研究发现脱落酸(ABA)和水杨酸(SA)作为植物的生长调节物质对于提高植物抗性,维持植物正常生长具有重要的意义.综述近年来国内外有关ABA和SA提高植物抗性的最新进展,为研究提高植物抗性提供理论参考.

  14. 不同生长素类型及ABA搭配对小麦幼胚再生效果的影响%EFFECTS OF DIFFERENT AUXINS AND COMBINING APPLICATION WITH ABA ON REGENERATION OF IMMATURE EMBRYOS OF WHEAT

    Institute of Scientific and Technical Information of China (English)

    别晓敏; 杜丽璞; 佘茂云; 徐惠君; 叶兴国

    2011-01-01

    生长素是小麦幼胚产生胚性愈伤组织的关键成分,培养基中适宜的生长素种类、浓度和组合决定着小麦幼胚再生效果。本研究以小麦基因型CB037幼胚为材料,在分别确定dicamba、2,4,5-T和picloram的适宜用量的基础上,比较了2,4-D、dicamba、2,4,5-T、picloram在适宜浓度下诱导再生的效果,筛选出ABA搭配2,4-D的最佳浓度组合。结果表明,dicamba、2,4,5-T和picloram的适宜用量分别为2.5mg/L、3.0mg/L和3.0mg/L,2,4-D诱导小麦幼胚再生效果最好,其次为dicamba,picloram和2,4,5-T诱导效果较差;在含有2,4-D 2.0mg/L的培养基中加入ABA 0.3mg/L能明显抑制幼胚直接萌发,显著提高胚性愈伤组织诱导率和再生率。%It is necessary to improve plant regeneration efficiency for cell and genetic engineering breeding of wheat.To investigate appropriate type and concentration of auxins(dicamba,2,4,5-T,picloram) and combination of 2,4-D and ABA for wheat immature embryo culture, a new wheat line CB037 was applied to investigate the influence of three auxins and combination effect of 2,4-D and ABA.Results showed that the optimal concentrations of dicamba,2,4,5-T,picloram when used alone were 2.5mg/L,3.0mg/L and 3.0mg/L,respectively.Compared to 2,4-D with the highest efficiencies in both of callus differentiation and green shoots induction,dicamba was the most suitable auxin to induce embryogenic callus other than to induce regeneration shoots,and 2,4,5-T and picloram followed the above two auxins either in embryogenic callus induction or green shoots induction.In the presence of 2.0mg/L 2,4-D and 0.3mg/L ABA in the callus induction medium,the best regeneration efficiency from the immature appeared,improving the callus quality and the green seedling numbers dramatically.

  15. 外源ABA和GA对番茄果实成熟发育中糖苷酶活性的影响%Effect of exogenous ABA and GA on glycosidases activities during tomato development and ripening

    Institute of Scientific and Technical Information of China (English)

    赫崇慧; 李景富; 王傲雪

    2011-01-01

    为了研究糖苷酶在番茄果实成熟和软化中的作用,以LA2895(GA突变体)果实为试材,研究了ABA和GA处理的番茄果实糖苷酶的变化情况.结果表明,GA对3-甘露糖苷酶具有负调控作用,而对α-L-阿拉伯糖苷、β-半乳糖苷酶和β-D-木糖苷酶起到正调控且放大酶信号的作用;ABA与GA以协同作用调控着β-D-木糖苷酶、β-半乳糖苷酶、α-L-阿拉伯糖苷酶和β-甘露糖苷酶,进而影响果实的成熟软化.该研究为进一步阐明果实成熟和软化机理奠定了理论基础.%In order to investigate the role of glycosidases during tomato ripening and softening, tomato line LA2895 (GA mutant) fruits used as experimental materials to study the changes of fruit glycosidases with the ABA and GA treatment. The results showed that GA could make β-D-xylosidase, β-galactosidase and α-L-arabinofuranosidase signal amplification and increased the these three enzyme activities, but GA can reduce the β-mannosidase activity. ABA and GA regulate β-D-xylosidase, β-galactosidase, a-L-arabinofuranosidase and β-mannosidase, regulating fruit ripening synergistically. This will provide the theoretical basis for further elucidating the mechanism of fruit ripening and softening.

  16. 外源ABA对木薯叶片内源激素及淀粉合成相关基因的影响%Change of endogenous hormones and expression levels of genes for ABA synthesis,signaling and starch synthesis in leaves of cassava under exogenous ABA treatment

    Institute of Scientific and Technical Information of China (English)

    王淑娟; 方开星; 陈新; 马平安; 周新成; 卢诚; 王文泉

    2015-01-01

    在盆栽条件下,用外源脱落酸(Abscisic acid,ABA)处理块根形成期的木薯品种,测定处理及对照在不同时刻叶片中ABA等激素变化、ABA合成与失活以及淀粉合成途径关键基因的表达变化.结果表明:1)正常条件下木薯叶片内源ABA水平及ABA合成途径基因均存在明显的夜间低而白天较高的昼夜节律,ABA信号转导相关基因也表现出下午的高峰表达,它们与淀粉合成途径基因的夜间表达一般具有相反的趋势.2)ABA处理后,木薯叶片内源ABA含量迅速下降,与观察到的ABA合成途径基因表这下降与后期ABA失活基因激活表达相一致,同时发现细胞分裂素中的玉米素核苷(Zeatin riboside,ZR)和生长素(Indole acetic acid,IAA)水平发生改变,预示木薯具有迅速恢复ABA平衡态的机制,并且与其他类激素存在协同作用.3)与此同时,外源ABA处理明显抑制淀粉合成上游基因表达,特别是夜晚高峰期的表达,而对下游基因的抑制相对较小.说明这些基因及枢关酶类不同程度受到ABA的调控;ABA明显倾向于调控淀粉合成上游相关基因;外源ABA处理改变了叶片临时淀粉合成速率.

  17. Applied behavior analytic intervention for autism in early childhood: meta-analysis, meta-regression and dose-response meta-analysis of multiple outcomes.

    Science.gov (United States)

    Virués-Ortega, Javier

    2010-06-01

    A number of clinical trials and single-subject studies have been published measuring the effectiveness of long-term, comprehensive applied behavior analytic (ABA) intervention for young children with autism. However, the overall appreciation of this literature through standardized measures has been hampered by the varying methods, designs, treatment features and quality standards of published studies. In an attempt to fill this gap in the literature, state-of-the-art meta-analytical methods were implemented, including quality assessment, sensitivity analysis, meta-regression, dose-response meta-analysis and meta-analysis of studies of different metrics. Results suggested that long-term, comprehensive ABA intervention leads to (positive) medium to large effects in terms of intellectual functioning, language development, acquisition of daily living skills and social functioning in children with autism. Although favorable effects were apparent across all outcomes, language-related outcomes (IQ, receptive and expressive language, communication) were superior to non-verbal IQ, social functioning and daily living skills, with effect sizes approaching 1.5 for receptive and expressive language and communication skills. Dose-dependant effect sizes were apparent by levels of total treatment hours for language and adaptation composite scores. Methodological issues relating ABA clinical trials for autism are discussed. PMID:20223569

  18. The Epiphytic Fern Elaphoglossum luridum (Fée Christ. (Dryopteridaceae from Central and South America: Morphological and Physiological Responses to Water Stress

    Directory of Open Access Journals (Sweden)

    Bruno Degaspari Minardi

    2014-01-01

    Full Text Available Elaphoglossum luridum (Fée Christ. (Dryopteridaceae is an epiphytic fern of the Atlantic Forest (Brazil. Anatomical and physiological studies were conducted to understand how this plant responds to water stress. The E. luridum frond is coriaceus and succulent, presenting trichomes, relatively thick cuticle, and sinuous cell walls in both abaxial and adaxial epidermis. Three treatments were analyzed: control, water deficit, and abscisic acid (ABA. Physiological studies were conducted through analysis of relative water content (RWC, photosynthetic pigments, chlorophyll a fluorescence, and malate content. No changes in RWC were observed among treatments; however, significant decreases in chlorophyll a content and photosynthetic parameters, including optimal irradiance (Iopt and maximum electron transport rate (ETRmax, were determined by rapid light curves (RLC. No evidence of crassulacean acid metabolism (CAM pathway was observed in E. luridum in response to either water deficit or exogenous application of ABA. On the other hand, malate content decreased in the E. luridum frond after ABA treatment, seeming to downregulate malate metabolism at night, possibly through tricarboxylic acid (TCA cycle regulation.

  19. Measuring stress signaling responses of stomata in isolated epidermis of graminaceous species.

    Science.gov (United States)

    Shen, Lei; Sun, Peng; Bonnell, Verity C; Edwards, Keith J; Hetherington, Alistair M; McAinsh, Martin R; Roberts, Michael R

    2015-01-01

    Our current understanding of guard cell signaling pathways is derived from studies in a small number of model species. The ability to study stomatal responses in isolated epidermis has been an important factor in elucidating the mechanisms by which the stomata of these species respond to environmental stresses. However, such approaches have rarely been applied to study guard cell signaling in the stomata of graminaceous species (including many of the world's major crops), in which the guard cells have a markedly different morphology to those in other plants. Our understanding of guard cell signaling in these important species is therefore much more limited. Here, we describe a procedure for the isolation of abaxial epidermal peels from barley, wheat and Brachypodium distachyon. We show that isolated epidermis from these species contains viable guard cells that exhibit typical responses to abscisic acid (ABA) and CO2, as determined by measurements of stomatal apertures. We use the epidermal peel assay technique to investigate in more detail interactions between different environmental factors in barley guard cells, and demonstrate that stomatal closure in response to external CO2 is inhibited at higher temperatures, whilst sensitivity to ABA is enhanced at 30°C compared to 20 and 40°C. PMID:26217375

  20. Measuring stress signalling responses of stomata in isolated epidermis of graminaceous species.

    Directory of Open Access Journals (Sweden)

    Lei eShen

    2015-07-01

    Full Text Available Our current understanding of guard cell signalling pathways is derived from studies in a small number of model species. The ability to study stomatal responses in isolated epidermis has been an important factor in elucidating the mechanisms by which the stomata of these species respond to environmental stresses. However, such approaches have rarely been applied to study guard cell signalling in the stomata of graminaceous species (including many of the world’s major crops, in which the guard cells have a markedly different morphology to those in other plants. Our understanding of guard cell signalling in these important species is therefore much more limited. Here, we describe a procedure for the isolation of abaxial epidermal peels from barley, wheat and Brachypodium distachyon. We show that isolated epidermis from these species contains viable guard cells that exhibit typical responses to abscisic acid (ABA and CO2, as determined by measurements of stomatal apertures. We use the epidermal peel assay technique to investigate in more detail interactions between different environmental factors in barley guard cells, and demonstrate that stomatal closure in response to external CO2 is inhibited at higher temperatures, whilst sensitivity to ABA is enhanced at 30°C compared to 20°C and 40°C.

  1. Phosphate-dependent root system architecture responses to salt stress

    KAUST Repository

    Kawa, Dorota

    2016-05-20

    Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced main root length and increased the number of lateral roots of Arabidopsis Col-0 seedlings. In combination with salt, low Pi dampened the inhibiting effect of mild salt stress (75mM) on all measured RSA components. At higher NaCl concentrations, the Pi deprivation response prevailed over the salt stress only for lateral root elongation. The Pi deprivation response of lateral roots appeared to be oppositely affected by abscisic acid (ABA) signaling compared to the salt stress response. Natural variation in the response to the combination treatment of salt and Pi starvation within 330 Arabidopsis accessions could be grouped into four response patterns. When exposed to double stress, in general lateral roots prioritized responses to salt, while the effect on main root traits was additive. Interestingly, these patterns were not identical for all accessions studied and multiple strategies to integrate the signals from Pi deprivation and salinity were identified. By Genome Wide Association Mapping (GWAS) 13 genomic loci were identified as putative factors integrating responses to salt stress and Pi starvation. From our experiments, we conclude that Pi starvation interferes with salt responses mainly at the level of lateral roots and that large natural variation exists in the available genetic repertoire of accessions to handle the combination of stresses.

  2. Uptake of (2-/sup 14/C)abscisic acid and distribution of /sup 14/C in apple embryos

    Energy Technology Data Exchange (ETDEWEB)

    Barthe, P.; Bulard, C.

    1981-01-01

    Pyrus malus L. var. Golden delicious embryos were incubated with (+-)-(2-/sup 14/C) abscisic acid (ABA). After incubations of various durations, the radioactivity was measured in whole embryos, cotyledons, and embryonic axes. With either 48-h or 16-d incubation periods, the uptake of (/sup 14/C) ABA depended upon the mode of culture used. The lowest values corresponded to the absorption by the embryonic axis, the highest to the absorption by the distal parts of the two cotyledons. The cotyledons accumulated the main part of the radioactivity under all conditions. Dormant and almost completely after-ripened embryos cultivated for 4 d showed no significant differences in the radioactivity uptake for identical modes of culture. There was a linear relationship between exogenous ABA concentrations (0.5 to 3.10/sup -5/ M) and ABA uptake for embryos cultivated for 4 d with the distal parts of the cotyledons immersed in the medium.

  3. Functional analysis of water stress-responsive soybean GmNAC003 and GmNAC004 transcription factors in lateral root development in arabidopsis.

    Directory of Open Access Journals (Sweden)

    Truyen N Quach

    Full Text Available In Arabidopsis, NAC (NAM, ATAF and CUC transcription factors have been found to promote lateral root number through the auxin signaling pathway. In the present study, the role of water stress-inducible soybean GmNAC003 and GmNAC004 genes in the enhancement of lateral root development under water deficit conditions was investigated. Both genes were highly expressed in roots, leaves and flowers of soybean and were strongly induced by water stress and moderately induced by a treatment with abscisic acid (ABA. They showed a slight response to treatment with 2,4-dichlorophenoxyacetic acid (2,4-D. The transgenic Arabidopsis plants overexpressing GmNAC004 showed an increase in lateral root number and length under non-stress conditions and maintained higher lateral root number and length under mild water stress conditions compared to the wild-type (WT, while the transgenic plants overexpressing GmNAC003 did not show any response. However, LR development of GmNAC004 transgenic Arabidopsis plants was not enhanced in the water-stressed compared to the well-watered treatment. In the treatment with ABA, LR density of the GmNAC004 transgenic Arabidopsis was less suppressed than that of the WT, suggesting that GmNAC004 counteracts ABA-induced inhibition of lateral root development. In the treatment with 2,4-D, lateral root density was enhanced in both GmNAC004 transgenic Arabidopsis and WT plants but the promotion was higher in the transgenic plants. Conversely, in the treatment with naphthylphthalamic acid (NPA, lateral root density was inhibited and there was no difference in the phenotype of the GmNAC004 transgenic Arabidopsis and WT plants, indicating that auxin is required for the action of GmNAC004. Transcript analysis for a number of known auxin and ABA related genes showed that GmNAC004's role may suppress ABA signaling but promote auxin signaling to increase lateral root development in the Arabidopsis heterologous system.

  4. Stomata prioritize their responses to multiple biotic and abiotic signal inputs.

    Directory of Open Access Journals (Sweden)

    Xiaobin Ou

    Full Text Available Stomata are microscopic pores in leaf epidermis that regulate gas exchange between plants and the environment. Being natural openings on the leaf surface, stomata also serve as ports for the invasion of foliar pathogenic bacteria. Each stomatal pore is enclosed by a pair of guard cells that are able to sense a wide spectrum of biotic and abiotic stresses and respond by precisely adjusting the pore width. However, it is not clear whether stomatal responses to simultaneously imposed biotic and abiotic signals are mutually dependent on each other. Here we show that a genetically engineered Escherichia coli strain DH5α could trigger stomatal closure in Vicia faba, an innate immune response that might depend on NADPH oxidase-mediated ROS burst. DH5α-induced stomatal closure could be abolished or disguised under certain environmental conditions like low [CO2], darkness, and drought, etc. Foliar spraying of high concentrations of ABA could reduce stomatal aperture in high humidity-treated faba bean plants. Consistently, the aggressive multiplication of DH5α bacteria in Vicia faba leaves under high humidity could be alleviated by exogenous application of ABA. Our data suggest that a successful colonization of bacteria on the leaf surface is correlated with stomatal aperture regulation by a specific set of environmental factors.

  5. Farnesylation mediates brassinosteroid biosynthesis to regulate abscisic acid responses.

    Science.gov (United States)

    Northey, Julian G B; Liang, Siyu; Jamshed, Muhammad; Deb, Srijani; Foo, Eloise; Reid, James B; McCourt, Peter; Samuel, Marcus A

    2016-01-01

    Protein farnesylation is a post-translational modification involving the addition of a 15-carbon farnesyl isoprenoid to the carboxy terminus of select proteins(1-3). Although the roles of this lipid modification are clear in both fungal and animal signalling, many of the mechanistic functions of farnesylation in plant signalling are still unknown. Here, we show that CYP85A2, the cytochrome P450 enzyme that performs the last step in brassinosteroid biosynthesis (conversion of castasterone to brassinolide)(4), must be farnesylated to function in Arabidopsis. Loss of either CYP85A2 or CYP85A2 farnesylation results in reduced brassinolide accumulation and increased plant responsiveness to the hormone abscisic acid (ABA) and overall drought tolerance, explaining previous observations(5). This result not only directly links farnesylation to brassinosteroid biosynthesis but also suggests new strategies to maintain crop yield under challenging climatic conditions. PMID:27455172

  6. Environment Zoning of Geological Hazards Development of Road Flood Based on Fuzzy Probability Method in Aba Area%基于模糊概率的阿坝州公路洪灾孕灾环境分区

    Institute of Scientific and Technical Information of China (English)

    唐红梅; 廖学海; 陈洪凯

    2014-01-01

    公路洪灾孕灾环境的合理分区可从理论上为公路洪灾的防治工作提供指导。以四川阿坝州为研究对象,根据公路洪灾致灾原理,遴选出公路沿线历史地质灾害发育、地貌条件、岩土体性质、年均降雨量、人口密度、植被覆盖度和地质构造7个因子,依据专家系统分为4级后赋值构成评价指标体系。综合层次分析法和专家效度法得到各指标的相对权重,并结合模糊理论给出模糊权重。采用模糊概率综合评价模型将公路洪灾孕灾环境分成低易发区、中易发区、高易发区和危险区4个危险等级。分区结果显示:阿坝州公路洪灾孕灾环境发展较为充分,以县为单位分成了高易发区、中易发区和低易发区,分别占全州面积的38.1%、39.4%和22.5%,研究成果对于该区公路洪灾的防治具有积极意义。%A fit environment zoning of geological hazards developing of road flood can provide theoretical ref-erences for the road flood prevention engineering.The road flood in Aba area,Sichuan province is studied.Ac-cording to the road flood causing principles,seven indexes are selected,such as historical geological hazards along the road,landforms,natures of rock and soil,average annual rainfall,population density,vegetation coverage and geological conditions,which are divided into four grades based on expert system,and then the comprehensive eval-uation model of environment zoning of geological hazards development is established after assessment.Each index is calculated by Analytical Hierarchy Process (AHP)and Expert Scoring Method,and then got the fuzzy weights combined fuzzy theory.According to the fuzzy comprehensive evaluation model of probability,the environment zoning of geological hazards development is divided into low easy-happening area,medium easy-happening area,high easy-happening area and dangerous area.The result shows that Aba area have sufficient environmental

  7. Analysis of the Characteristics of Tibetan Patients with Orthodontic Treatment in Barkam of Aba Prefecture%阿坝州马尔康地区藏族口腔正畸患者的特征分析

    Institute of Scientific and Technical Information of China (English)

    肖遥; 郑立舸; 江蓉; 白晓东; 钟应权

    2014-01-01

    Objective To know the characteristics of Tibetan patients with orthodontic treatment in Barkam of Aba prefec-ture,to improve Tibetan oral health consciousness. Methods 226 tibetan orthodontic patients(90 males and 136 females) were selected in recent 8 years in Aba Prefecture People′s Hospital. Through the retrospective analysis of clinical data,to record and sta-tistic their classification of malocclusion,medical reasons,oral habits,oral health status,age distribution and so on. Results The majority of Tibetan patients with orthodontic treatment were female adolescents ( P <0. 05 ) . Angle II malocclusion were in the most,and Angle III malocclusion were in the least(P<0. 05),the most common Clinical manifestation were dental crowding,deep overbite and deep overjet. Medical reason was given priority to with the wishes of parents of the aesthetic requirements(P<0. 05). The most common oral habits was to bite lips. Dental caries incidence was 67. 3%,there was no significant differences between male and female. Conclusion There was a certain characteristic in tibetan patients with orthodontic treatment in Barkam of aba pre-fecture,we need to strengthen the oral health care knowledge education.%目的:了解阿坝州马尔康地区藏族人口腔正畸治疗的特征,提高藏区口腔保健意识。方法选取马尔康地区近8年来就诊的藏族口腔正畸患者226例,男90例,女136例,通过对病例资料的回顾性分析,记录并统计其错类别、就诊原因、口腔不良习惯、口腔健康状况、年龄分布等信息。结果就诊的藏族患者中以女性青少年居多( P<0.05);错以安氏Ⅱ类最多,安氏Ⅲ类最少(P<0.05),表现以牙列拥挤、前牙深覆合深覆盖为主;就诊原因以家长意愿的美观要求为主(P<0.05);口腔不良习惯以咬唇居多;龋齿发病率为67.3%,男女差异无统计学意义。结论阿坝州马尔康地区藏族口腔正畸治疗患者有一定的特征

  8. 外源ABA和GA对小麦籽粒内源激素含量及其灌浆进程的影响%Effects of Spraying Exogenous ABA or GA on the Endogenous Hormones Concentration and Filling of Wheat Grains

    Institute of Scientific and Technical Information of China (English)

    杨卫兵; 蔡铁; 倪英丽; 王振林; 尹燕枰; 李文阳; 李勇; 陈晓光; 王平; 陈二影; 郭俊祥

    2011-01-01

    [目的]探讨喷施外源脱落酸(ABA)或赤霉素(GA)对小麦籽粒内源激素含量及其灌浆进程的影响,为激素调控提高籽粒的粒重提供理论依据.[方法]试验选用山农1391和藁城8901两个品种,籽粒灌浆初期喷施ABA或GA两种外源激素于穗部,定期取籽粒样品,用高效液相色谱法测定籽粒内源激素含量,用三次多项方程式对籽粒灌浆进程进行模拟并分析相关参数.[结果]喷施外源ABA或GA均能显著增加两个品种的粒重.外源ABA或GA对粒重的调控存在粒位效应.喷施ABA显著增加强势粒粒重,喷施GA使强势粒和弱势粒粒重均显著增加.喷施外源ABA显著提高籽粒ABA含量,喷施外源GA显著提高籽粒GA含量,喷施外源ABA或外源GA均显著提高灌浆中后期籽粒IAA和CTK的含量,尤其是喷施外源GA效果更为明显.喷施外源ABA或外源GA均能延长籽粒的灌浆持续期,喷施ABA显著提高灌浆初期强势粒的灌浆速率,而喷施GA显著提高灌浆中后期强势粒和弱势粒的灌浆速率.[结论]喷施外源ABA或外源GA通过改变籽粒内源激素水平,调节灌浆起始时间和籽粒灌浆持续期,进而调控籽粒粒重的形成.喷施ABA是通过提高强势粒粒重来增加粒重的,喷施GA是通过提高强势粒和弱势粒的粒重来增加粒重的.%[ Objective ] The objective of the experiment is to explore the relationship between exogenous ABA and GA to the levels of endogenous hormones in grains and the grain filling, and provide a theoretical basis for increasing grain weight under the regulation of exogenous hormone. [Method] The field experiments were carried out at Taian Experimental Station of Shandong Agricultural University, two cultivars Shannong 1391 and Gaocheng 8901 were planted in the farm, exogenous ABA or GA to the spikes were sprayed at initial grain filling stage, spikes were sampled after anthesis till maturity, and grains were partitioned into two groups, superior grains

  9. Identification and primary genetic analysis of Arabidopsis stomatal mutants in response to multiple stresses

    Institute of Scientific and Technical Information of China (English)

    SONG Yuwei; KANG Yanli; LIU Hao; ZHAO Xiaoliang; WANG Pengtao; AN Guoyong; ZHOU Yun; MIAO Chen; SONG Chunpeng

    2006-01-01

    In response to variable environmental conditions, guard cells located in the leaf epidermis can integrate and cope with a multitude of complicated stimuli, thereby making stomata in an appropriate state. However, many signaling components in guard cell signaling remain elusive. In our laboratory,a tool for non-invasive remote infrared thermal images was used to screen an ethyl methane sulfonate-mutagenized population for Arabidopsis stomatal response mutants under multiple stresses (ABA, H2O2, CO2, etc.). More than forty "hot" or "cold"mutants were isolated (above or below 0.5℃ in contrast to normal plantlets). Identification and primary genetic analysis of these mutants show that they are monogenic recessive mutations and there exist distinct difference in stomata apertures compared to wild type. These mutants in response to various environmental stresses and hormones were comprehensively investigated, which enables us to further understand the cross-talk in different signal transduction pathways.

  10. ZmNAC55, a maize stress-responsive NAC transcription factor, confers drought resistance in transgenic Arabidopsis.

    Science.gov (United States)

    Mao, Hude; Yu, Lijuan; Han, Ran; Li, Zhanjie; Liu, Hui

    2016-08-01

    Abiotic stress has been shown to significantly limit the growth and productivity of crops. NAC transcription factors play essential roles in response to various abiotic stresses. However, only little information regarding stress-related NAC genes is available in maize. Here, we cloned a maize NAC transcription factor ZmNAC55 and identified its function in drought stress. Transient expression and transactivation assay demonstrated that ZmNAC55 was localized in the nucleus and had transactivation activity. Expression analysis of ZmNAC55 in maize showed that this gene was induced by drought, high salinity and cold stresses and by abscisic acid (ABA). Promoter analysis demonstrated that multiple stress-related cis-acting elements exist in promoter region of ZmNAC55. Overexpression of ZmNAC55 in Arabidopsis led to hypersensitivity to ABA at the germination stage, but enhanced drought resistence compared to wild-type seedlings. Transcriptome analysis identified a number of differentially expressed genes between 35S::ZmNAC55 transgenic and wild-type plants, and many of which are involved in stress response, including twelve qRT-PCR confirmed well-known drought-responsive genes. These results highlight the important role of ZmNAC55 in positive regulates of drought resistence, and may have potential applications in transgenic breeding of drought-tolerant crops. PMID:27085597

  11. Expression profiles and transactivation analysis of a novel ethylene-responsive transcription factor gene GhERF5 from cotton

    Institute of Scientific and Technical Information of China (English)

    Longguo Jin; Bo Huang; Hui Li; Jinyuan Liu

    2009-01-01

    Plant AP2/EREBP transcription factors play important roles in plant development and in plant responses to biotic and abiotic stresses.A novel gene for ethylene-responsive element binding protein (EREBP),designated GhERF5,which encodes a protein of 255 amino acids,was isolated by RACE-PCR from cotton (Gossypium hirsutum) seedlings.Sequence alignment revealed that GhERF5 contains a typical AP2/ERF domain,and belongs to the B3 subgroup of the ERF subfamily.Particle bombardment assay showed that GhERF5 functions as an in vivo transcription activator in tobacco cells,and it is located in the nuclei of onion epidermis cells.Semi-quantitative RT-PCR revealed that the expression of GhERF5 was highly and rapidly induced when plants were treated with exogenous ethylene,abscisic acid (ABA),salt,cold and drought.Promoter analysis indicated that there are conserved cis-acting elements induced by these stresses in the 5'-upstream region of the GhERF5 gene.These results suggest that the GhERF5 gene might play an important role in cotton response to ethylene,ABA and environmental stresses.(C)2008 National Natural Science Foundation of China and Chinese Academy of Sciences.Published by Elsevier Limited and Science in China Press.All rights reserved.

  12. Comparative transcriptional profiling of melatonin synthesis and catabolic genes indicates the possible role of melatonin in developmental and stress responses in rice

    Directory of Open Access Journals (Sweden)

    Yunxie eWei

    2016-05-01

    Full Text Available As a well-known animal hormone, melatonin (N-acetyl-5-methoxytryptamine is also involved in multiple plant biological processes, especially in various stress responses. Rice is one of the most important crops, and melatonin is taken in by many people everyday from rice. However, the transcriptional profiling of melatonin-related genes in rice is largely unknown. In this study, the expression patterns of 11 melatonin related genes in rice in different periods, tissues, in response to different treatments were synthetically analyzed using published microarray data. These results suggest that the melatonin-related genes may play important and dual roles in rice developmental stages. We highlight the commonly regulation of rice melatonin-related genes by abscisic acid (ABA, jasmonic acid (JA, various abiotic stresses and pathogen infection, indicating the possible role of these genes in multiple stress responses and underlying crosstalks of plant hormones, especially ABA and JA. Taken together, this study may provide insight into the association among melatonin biosynthesis and catabolic pathway, plant development and stress responses in rice. The profile analysis identified candidate genes for further functional characterization in circadian rhythm and specific stress responses.

  13. 水分胁迫积累的ABA诱导抗氧化防护系统的信号级联%Signal Cascads of Antioxidative Defenses Induced by Water Stress-accumulated ABA

    Institute of Scientific and Technical Information of China (English)

    胡秀丽; 刘瑞侠; 毛训甲

    2007-01-01

    水分胁迫是限制植物生长发育的主要胁迫因子之一.植物通过感受刺激,产生和传递信号、启动多种防御机制对水分胁迫做出响应和适应.脱落酸(ABA)作为一种重要的植物体内胁迫激素,参与了许多这样的反应.研究表明,ABA增强植物水分胁迫的忍耐力与ABA诱导的抗氧化剂防护系统有关;且细胞溶质Ca2+([Ca2+],)、活性氧(ROS)等许多第二信使参与了ABA诱导的信号转导过程.本文就这些信号分子在水分胁迫积累的内源ABA诱导的抗氧化剂防护系统中的作用作一综述.

  14. Syntheses, crystal structure, and electronic properties of the five ABaMQ4 compounds RbBaPS4, CsBaPS4, CsBaVS4, RbBaVSe4, and CsBaVSe4

    Science.gov (United States)

    Mesbah, Adel; Prakash, Jai; Rocca, Dario; Lebègue, Sébastien; Beard, Jessica C.; Lewis, Benjamin A.; Ibers, James A.

    2016-01-01

    Five new compounds belonging to the ABaMQ4 family were synthesized by solid-state chemistry at 1123 K. The compounds RbBaPS4, CsBaPS4, CsBaVS4, RbBaVSe4, and CsBaVSe4 are isostructural and have the TlEuPS4 structure type. They crystallize in space group D162h - Pnma of the orthorhombic system. Their structure consists isolated MQ4 tetrahedra separated by A and Ba atoms to form a salt-like structure. Density Functional Theory (DFT) calculations of the electronic structures with the use of the HSE functional suggest that the compounds are semiconductors with calculated band gaps of 3.3 eV (RbBaPS4), 3.4 eV (CsBaPS4), 2.3 eV (CsBaVS4), and 1.6 eV (RbBaVSe4).

  15. GA3、ABA和6-BA对大豆根系生长的影响%Effects of GA3, ABA and 6-BA on soybean,Glycine max L.Merrill, root growth and development

    Institute of Scientific and Technical Information of China (English)

    李欣欣; 廖红; 赵静

    2014-01-01

    [Objective]This experiment was conducted to explore effects of different concentrations of GA3 , ABA, and 6-BA on soybean root growth , which could provide a theoretical basis for a further con-trol of soybean root architecture through phytohormone .[Method]The seedlings of soybean cultivar“HN89” were treated with 0.05, 0.50, 1.00, and 5.00 μmol· L-1 gibberellin (GA3), abscisic acid ( ABA) and cytokinin (6-BA) respectively for 4 days, then root morphological parameters were quanti-fied and analyzed .[Result and conclusion]The results showed that 0.05 μmol· L-1 GA3 promoted the total root length of soybeans , but increasing GA 3 concentration would constrain primary root and lateral root growth, which decreased the total root length .GA3 decreased average root diameters , hence resulting in fine roots.0.05 μmol· L-1 ABA did not affect the soybean root growth , while increasing ABA con-centration higher than 0.5μmol· L-1 inhibited primary root and lateral root growth , decreasing the total root length , and slightly increasing average root diameters .6-BA significantly constrained the soybean root growth and development , for instance , it inhibited primary root elongation , lateral rooting , and the total root length , but it promoted average root diameter , resulting in thick roots .These results indicated that different phytohormones or similar phytohormone with different concentrations can control soybean root architecture by controlling primary roots and lateral roots growth in different ways .%【目的】研究不同浓度赤霉素(GA3)、脱落酸(ABA)和细胞分裂素(6-BA)对大豆根系生长的影响,为进一步利用激素调控大豆根系构型提供理论依据.【方法】以大豆品种“HN89”为材料,分别用浓度为0.05、0.50、1.00和5.00μmol· L-1的GA3、ABA和6-BA处理大豆幼苗4 d,利用根系分析软件定量分析根系形态参数的变化.【结果和结论】0.05μmol · L-1 GA3处理可

  16. Nonrigid registration algorithm for longitudinal breast MR images and the preliminary analysis of breast tumor response

    Science.gov (United States)

    Li, Xia; Dawant, Benoit M.; Welch, E. Brian; Chakravarthy, A. Bapsi; Freehardt, Darla; Mayer, Ingrid; Kelley, Mark; Meszoely, Ingrid; Gore, John C.; Yankeelov, Thomas E.

    2009-02-01

    Although useful for the detection of breast cancers, conventional imaging methods, including mammography and ultrasonography, do not provide adequate information regarding response to therapy. Dynamic contrast enhanced MRI (DCE-MRI) has emerged as a promising technique to provide relevant information on tumor status. Consequently, accurate longitudinal registration of breast MR images is critical for the comparison of changes induced by treatment at the voxel level. In this study, a nonrigid registration algorithm is proposed to allow for longitudinal registration of breast MR images obtained throughout the course of treatment. We accomplish this by modifying the adaptive bases algorithm (ABA) through adding a tumor volume preserving constraint in the cost function. The registration results demonstrate the proposed algorithm can successfully register the longitudinal breast MR images and permit analysis of the parameter maps. We also propose a novel validation method to evaluate the proposed registration algorithm quantitatively. These validations also demonstrate that the proposed algorithm constrains tumor deformation well and performs better than the unconstrained ABA algorithm.

  17. Responses of the Drought-Resistent vem1 Mutant to NaCl and ABA Stress in Arabidopsis%拟南芥抗旱突变体vem1对NaCl和ABA胁迫的响应

    Institute of Scientific and Technical Information of China (English)

    杨杰; 江力; 张娇娇; 陈子平

    2013-01-01

    我们从拟南芥突变体库中筛选获得一抗旱突变体vem1.本文通过观察突变体表型,测定其脯氨酸、可溶糖、叶绿素含量和相对电导率等抗逆相关的生理指标,研究突变体vem1对NaCl和ABA胁迫的响应.NaCl胁迫下,突变体vem1比野生型(WT)积累更多的脯氨酸和可溶性糖,而相对电导率、叶绿素含量均比WT低.ABA胁迫下,vem1积累的脯氨酸、可溶糖和叶绿素含量均低于WT,而相对电导率和胁迫相关基因RD29A表达量高于WT.结果表明,vem1对NaCl胁迫具有一定的抗性,对ABA胁迫表现敏感.研究为抗旱基因VEM1克隆及功能分析奠定基础.

  18. A defective ABC transporter of the MRP family, responsible for the bean lpa1 mutation, affects the regulation of the phytic acid pathway, reduces seed myo-inositol and alters ABA sensitivity

    OpenAIRE

    Panzeri, D; Cassani, E; Doria, E; Tagliabue, G; Forti, L; Campion, B; Bollini, R; Brearley, CA; Pilu, R; Nielsen, E.; Sparvoli, F

    2011-01-01

    We previously identified the lpa1 (low phytic acid) 280-10 line that carries a mutation conferring a 90% reduction in phytic acid (InsP6) content. In contrast to other lpa mutants, lpa1(280-10) does not display negative pleiotropic effects. In the present paper, we have identified the mutated gene and analysed its impact on the phytic acid pathway. Here, we mapped the lpa1(280-10) mutation by bulk analysis on a segregating F2 population, an then, by comparison with the soybean genome, we iden...

  19. Rapid responses of C14 clone of Eucalyptus globulus to root drought stress: Time-course of hormonal and physiological signaling.

    Science.gov (United States)

    Granda, Víctor; Cuesta, Candela; Alvarez, Rubén; Ordás, Ricardo; Centeno, María Luz; Rodríguez, Ana; Majada, Juan Pedro; Fernández, Belén; Feito, Isabel

    2011-05-01

    The responses of juvenile plants of forest crops to drought stress are a key stage in the survival of forest populations. In this work, a suitable experimental system to study the early drought resistance mechanisms and signaling in a drought-tolerant clone (C14) of Eucalyptus globulus Labill is proposed. This system, using hydroponic culture and an osmotic agent, polyethylene glycol 8000, was demonstrated to induce severe stress in the root area, affecting the responses of the plantlets at the aerial level. These responses were very fast, beginning only 3h after the induction of stress, and the results highlight the roles of xylematic abscisic acid (ABA) and pH changes over other signals, such as cytokinins, as early chemical signals in rapid water stress. The relationship between these chemical factors, ABA and pH, and the physiological and water parameters observed were significant, supporting their proposed principal role. This work aids our understanding of underlying responses to hydrological limitations of forest crops, and provides valuable information for further physiological and molecular studies of water stress in this and other tree species.

  20. OsSIDP366, a DUF1644 gene, positively regulates responses to drought and salt stresses in rice

    Institute of Scientific and Technical Information of China (English)

    Chiming Guo; Chengke Luo; Lijia Guo; Min Li; Xiaoling Guo; Yuxia Zhang; Liangjiang Wang; Liang Chen

    2016-01-01

    Domain of unknown function 1644 (DUF1644) is a highly conserved amino acid sequence motif present only in plants. Analysis of expression data of the family of DUF1644-containing genes indicated that they may regulate responses to abiotic stress in rice. Here we present our discovery of the role of OsSIDP366, a member of the DUF1644 gene family, in response to drought and salinity stresses in rice. Transgenic rice plants overexpressing OsSIDP366 showed enhanced drought and salinity tolerance and reduced water loss as compared to that in the control, whereas plants with downregulated OsSIDP366 expression levels using RNA interference (RNAi) were more sensitive to salinity and drought treatments. The sensitivity to abscisic acid (ABA) treatment was not changed in OsSIDP366-overexpressing plants, and OsSIDP366 expression was not affected in ABA-deficient mutants. Subcellular localization analysis revealed that OsSIDP366 is presented in the cytoplasmic foci that colocalized with protein markers for both processing bodies (PBs) and stress granules (SGs) in rice protoplasts. Digital gene expression (DGE) profile analysis indicated that stress-related genes such as SNAC1, OsHAK5 and PRs were upregulated in OsSIDP366-overexpressing plants. These results suggest that OsSIDP366 may function as a regulator of the PBs/SGs and positively regulate salt and drought resistance in rice.

  1. OsSIDP366, a DUF1644 gene, positively regulates responses to drought and salt stresses in rice.

    Science.gov (United States)

    Guo, Chiming; Luo, Chengke; Guo, Lijia; Li, Min; Guo, Xiaoling; Zhang, Yuxia; Wang, Liangjiang; Chen, Liang

    2016-05-01

    Domain of unknown function 1644 (DUF1644) is a highly conserved amino acid sequence motif present only in plants. Analysis of expression data of the family of DUF1644-containing genes indicated that they may regulate responses to abiotic stress in rice. Here we present our discovery of the role of OsSIDP366, a member of the DUF1644 gene family, in response to drought and salinity stresses in rice. Transgenic rice plants overexpressing OsSIDP366 showed enhanced drought and salinity tolerance and reduced water loss as compared to that in the control, whereas plants with downregulated OsSIDP366 expression levels using RNA interference (RNAi) were more sensitive to salinity and drought treatments. The sensitivity to abscisic acid (ABA) treatment was not changed in OsSIDP366-overexpressing plants, and OsSIDP366 expression was not affected in ABA-deficient mutants. Subcellular localization analysis revealed that OsSIDP366 is presented in the cytoplasmic foci that colocalized with protein markers for both processing bodies (PBs) and stress granules (SGs) in rice protoplasts. Digital gene expression (DGE) profile analysis indicated that stress-related genes such as SNAC1, OsHAK5 and PRs were upregulated in OsSIDP366-overexpressing plants. These results suggest that OsSIDP366 may function as a regulator of the PBs/SGs and positively regulate salt and drought resistance in rice. PMID:26172270

  2. Basic Techniques to Assess Seed Germination Responses to Abiotic Stress in Arabidopsis thaliana.

    Science.gov (United States)

    Piskurewicz, Urszula; Lopez-Molina, Luis

    2016-01-01

    The model organism Arabidopsis thaliana has been extensively used to unmask the molecular genetic signaling pathways controlling seed germination in plants. In Arabidopsis, the normal seed to seedling developmental transition involves testa rupture soon followed by endosperm rupture, radicle elongation, root hair formation, cotyledon expansion, and greening. Here we detail a number of basic procedures to assess Arabidopsis seed germination in response to different light (red and far-red pulses), temperature (seed thermoinhibition), and water potential (osmotic stress) environmental conditions. We also discuss the role of the endosperm and how its germination-repressive activity can be monitored genetically by means of a seed coat bedding assay. Finally we detail how to evaluate germination responses to changes in gibberellin (GA) and abscisic acid (ABA) levels by manipulating pharmacologically the germination medium. PMID:26867624

  3. PDR-type ABC transporter mediates cellular uptake of the phytohormone abscisic acid

    OpenAIRE

    Kang, J; Hwang, J U; Lee, M; Kim, Y. Y.; Assmann, S M; Martinoia, E.; Lee, Y

    2010-01-01

    Abscisic acid (ABA) is a ubiquitous phytohormone involved in many developmental processes and stress responses of plants. ABA moves within the plant, and intracellular receptors for ABA have been recently identified; however, no ABA transporter has been described to date. Here, we report the identification of the ATP-binding cassette (ABC) transporter Arabidopsis thaliana Pleiotropic drug resistance transporter PDR12 (AtPDR12)/ABCG40 as a plasma membrane ABA uptake transporter. Uptake of ABA ...

  4. 地涌金莲种子形态生理休眠及激素的动态变化%Morphophysiological Dormancy and Changes of Endogenous ABA and GA4 Contents in Seeds of Musella lasiocarpa

    Institute of Scientific and Technical Information of China (English)

    唐安军

    2014-01-01

    珍稀植物地涌金莲在野外能产生大量的种子,但成熟的种子散布后不能顺利地转化为幼苗。在暖层积(25℃)过程中,蘑菇形的小胚逐渐分化与生长,6个月后,胚已形态成熟且能很好地萌发;同时,胚内激素ABA含量不断下降, GA4含量显著增加,且与胚的形态成熟和萌发力的增强密切相关。这些结果充分证实地涌金莲种子具有形态生理休眠--在很大程度上限制了野外种子萌发。此外,种子不萌发可能与生境长时间干旱胁迫有关。%Rare Musella lasiocarpa can naturally produce many seeds that don’t develop into seedlings after shedding. The mushroom-shaped small embryos without obvious differentiation would gradually differentiate and grew in the process of warm stratiifcation at 25℃. After 6-month warm stratiifcation, the embryos matured and could germinate well. At the same time, endogenous ABA constantly decreased and however, GA4 markedly increased over time, which was signiifcantly associated with embryo growth and germinability (R2=0.97). Thus, the results fully conifrmed that seeds of this species are morphological dormancy, which restricts the germina-tion of M. lasicocarpa seeds to a great extent in the wild. Also, the phenomenon that the seeds cannot germinate in the habitat is closely related with long drought stress in a dry season.

  5. IPT对稻苗根系生长和三种内源激素水平的影响%Effects of IPT on the Growth of Roots and Contents of IAA,Cytokinins and ABA in Rice Seedling

    Institute of Scientific and Technical Information of China (English)

    张红心; 王伟中; 夏凯; 周燮

    2000-01-01

    适宜浓度(0.1 mg/L)的IPT(isoprothiolane)浸泡水稻种子24小时,稻苗的种子根长度,侧根数目以及芽鞘节根长度,根系的干重均受到显著的促进。与之相对应的是,IPT处理后,种子根的内源1AA和ABA的含量提高,而iPAs和ZRs的含量下降。IPT处理也增加了稻苗的根系活力,提高了低温条件下POD(过氧化物酶)和CAT(过氧化氢酶)的活性。%The seeds of hybrid rice cv.Shanyou 63 were soaked in IPT(isoprothiolane) solution with various concentrations (0.1~100.0 mg/L) for 24h.It was found that 0.1 mg/L IPT significantly promoted the length of seminal root and crown roots, and 0.1~100.0 mg/L IPT significantly promoted the lateral root number in seminal root.Subsequently,plant hormones contents in root were determined by enzyme-linked immunoassay assays (ELISAs).It was found that the contents of IAA and ABA increased in seminal root,whereas those of iPAs and ZRs decreased after IPT treatment. Finally, the root activities were determined, It was found that the TTC reducing capacity of roots increased obviously, Both POD and CAT activities in roots treated with IPT were higher than those of the control under low temperature.

  6. Response and Responsibility

    OpenAIRE

    Clive L. Spash

    2012-01-01

    Why should anyone bother about social or environmental problems beyond responding to the signals in society to behave in an appropriate and caring manner towards others? This is a conundrum which has repeatedly surfaced and continues to resurface in the literature on environmental values and more generally in political theory. That is, what is the responsibility of the individual to society, others, the unborn, non-humans or inanimate Nature?

  7. A nucleotide metabolite controls stress-responsive gene expression and plant development.

    Directory of Open Access Journals (Sweden)

    Hao Chen

    Full Text Available Abiotic stress, such as drought and high salinity, activates a network of signaling cascades that lead to the expression of many stress-responsive genes in plants. The Arabidopsis FIERY1 (FRY1 protein is a negative regulator of stress and abscisic acid (ABA signaling and exhibits both an inositol polyphosphatase and a 3',5'-bisphosphate nucleotidase activity in vitro. The FRY1 nucleotidase degrades the sulfation byproduct 3'-phosphoadenosine-5'-phosphate (PAP, yet its in vivo functions and particularly its roles in stress gene regulation remain unclear. Here we developed a LC-MS/MS method to quantitatively measure PAP levels in plants and investigated the roles of this nucleotidase activity in stress response and plant development. It was found that PAP level was tightly controlled in plants and did not accumulate to any significant level either under normal conditions or under NaCl, LiCl, cold, or ABA treatments. In contrast, high levels of PAP were detected in multiple mutant alleles of FRY1 but not in mutants of other FRY1 family members, indicating that FRY1 is the major enzyme that hydrolyzes PAP in vivo. By genetically reducing PAP levels in fry1 mutants either through overexpression of a yeast PAP nucleotidase or by generating a triple mutant of fry1 apk1 apk2 that is defective in the biosynthesis of the PAP precursor 3'-phosphoadenosine-5'-phosphosulfate (PAPS, we demonstrated that the developmental defects and superinduction of stress-responsive genes in fry1 mutants correlate with PAP accumulation in planta. We also found that the hypersensitive stress gene regulation in fry1 requires ABH1 but not ABI1, two other negative regulators in ABA signaling pathways. Unlike in yeast, however, FRY1 overexpression in Arabidopsis could not enhance salt tolerance. Taken together, our results demonstrate that PAP is critical for stress gene regulation and plant development, yet the FRY1 nucleotidase that catabolizes PAP may not be an in vivo salt

  8. A nucleotide metabolite controls stress-responsive gene expression and plant development

    KAUST Repository

    Chen, Hao

    2011-10-19

    Abiotic stress, such as drought and high salinity, activates a network of signaling cascades that lead to the expression of many stress-responsive genes in plants. The Arabidopsis FIERY1 (FRY1) protein is a negative regulator of stress and abscisic acid (ABA) signaling and exhibits both an inositol polyphosphatase and a 3?,5?-bisphosphate nucleotidase activity in vitro. The FRY1 nucleotidase degrades the sulfation byproduct 3?-phosphoadenosine-5?-phosphate (PAP), yet its in vivo functions and particularly its roles in stress gene regulation remain unclear. Here we developed a LC-MS/MS method to quantitatively measure PAP levels in plants and investigated the roles of this nucleotidase activity in stress response and plant development. It was found that PAP level was tightly controlled in plants and did not accumulate to any significant level either under normal conditions or under NaCl, LiCl, cold, or ABA treatments. In contrast, high levels of PAP were detected in multiple mutant alleles of FRY1 but not in mutants of other FRY1 family members, indicating that FRY1 is the major enzyme that hydrolyzes PAP in vivo. By genetically reducing PAP levels in fry1 mutants either through overexpression of a yeast PAP nucleotidase or by generating a triple mutant of fry1 apk1 apk2 that is defective in the biosynthesis of the PAP precursor 3?-phosphoadenosine-5?-phosphosulfate (PAPS), we demonstrated that the developmental defects and superinduction of stress-responsive genes in fry1 mutants correlate with PAP accumulation in planta. We also found that the hypersensitive stress gene regulation in fry1 requires ABH1 but not ABI1, two other negative regulators in ABA signaling pathways. Unlike in yeast, however, FRY1 overexpression in Arabidopsis could not enhance salt tolerance. Taken together, our results demonstrate that PAP is critical for stress gene regulation and plant development, yet the FRY1 nucleotidase that catabolizes PAP may not be an in vivo salt toxicity target

  9. The pepper late embryogenesis abundant protein CaLEA1 acts in regulating abscisic acid signaling, drought and salt stress response.

    Science.gov (United States)

    Lim, Chae Woo; Lim, Sohee; Baek, Woonhee; Lee, Sung Chul

    2015-08-01

    As sessile organisms, plants are constantly challenged by environmental stresses, including drought and high salinity. Among the various abiotic stresses, osmotic stress is one of the most important factors for growth and significantly reduces crop productivity in agriculture. Here, we report a function of the CaLEA1 protein in the defense responses of plants to osmotic stress. Our analyses showed that the CaLEA1 gene was strongly induced in pepper leaves exposed to drought and increased salinity. Furthermore, we determined that the CaLEA1 protein has a late embryogenesis abundant (LEA)_3 homolog domain highly conserved among other known group 5 LEA proteins and is localized in the processing body. We generated CaLEA1-silenced peppers and CaLEA1-overexpressing (OX) transgenic Arabidopsis plants to evaluate their responses to dehydration and high salinity. Virus-induced gene silencing of CaLEA1 in pepper plants conferred enhanced sensitivity to drought and salt stresses, which was accompanied by high levels of lipid peroxidation in dehydrated and NaCl-treated leaves. CaLEA1-OX plants exhibited enhanced sensitivity to abscisic acid (ABA) during seed germination and in the seedling stage; furthermore, these plants were more tolerant to drought and salt stress than the wild-type plants because of enhanced stomatal closure and increased expression of stress-responsive genes. Collectively, our data suggest that CaLEA1 positively regulates drought and salinity tolerance through ABA-mediated cell signaling. PMID:25302464

  10. Corporate Responsibility

    DEFF Research Database (Denmark)

    Waddock, Sandra; Rasche, Andreas

    2015-01-01

    We define and discuss the concept of corporate responsibility. We suggest that corporate responsibility has some unique characteristics, which makes it different from earlier conceptions of corporate social responsibility. Our discussion further shows commonalities and differences between corporate...... responsibility and related concepts, such as corporate citizenship and business ethics. We also outline some ways in which corporations have implemented corporate responsibility in practice....

  11. Exploring jasmonates in the hormonal network of drought and salinity responses

    Directory of Open Access Journals (Sweden)

    Michael eRiemann

    2015-12-01

    Full Text Available Present and future food security is a critical issue compounded by the consequences of climate change on agriculture. Stress perception and signal transduction in plants causes changes in gene or protein expression which lead to metabolic and physiological responses. Phytohormones play a central role in the integration of different upstream signals into different adaptive outputs such as changes in the activity of ion-channels, protein modifications, protein degradation and gene expression. Phytohormone biosynthesis and signalling, and recently also phytohormone crosstalk have been investigated intensively, but the function of jasmonates under abiotic stress is still only partially understood. Although most aspects of jasmonate biosynthesis, crosstalk and signal transduction appear to be similar for biotic and abiotic stress, novel aspects have emerged that seem to be unique for the abiotic stress response. Here, we review the knowledge on the role of jasmonates under drought and salinity. The crosstalk of jasmonate biosynthesis and signal transduction pathways with those of abscisic acid (ABA is particularly taken into account due to the well-established, central role of ABA under abiotic stress. Likewise, the accumulating evidence of crosstalk of jasmonate signalling with other phytohormones is considered as important element of an integrated phytohormonal response. Finally, protein post-translational modification (PTM, which can also occur without de novo transcription, is treated with respect to its implications for phytohormone biosynthesis, signalling and crosstalk. To breed climate-resilient crop varieties, integrated understanding of the molecular processes is required to modulate and tailor particular nodes of the network to positively affect stress tolerance.

  12. Eco-physiological response of Populus euphratica Oliv. to water release of the lower reaches of the Tarim River, China

    Science.gov (United States)

    Wang, Q.; Ruan, X.; Chen, Y. N.; Li, W. H.

    2007-10-01

    Eco-physiological and plant performance responses and acclimation of Populus euphratica Oliv. to water release of the lower reaches of Tarim River, China were investigated. Three representative areas and 15 transects were selected along the lower reaches of the Tarim River. The groundwater level and salt content as well as plant performance and the contents of proline, soluble sugar, and plant endogenous hormone (ABA, CTK) in leaves were monitored and analyzed before- and after-water release. The groundwater level was raised in different areas and transects by the water release program. The physiological stress to P. euphratica decreased after the water release. Our results suggested that the groundwater level in the studied region changed from -3.15 to -4.12 m, salt content of the groundwater from 67.15 to 72.65 mM, the proline content from 9.28 to 11.06 mM, the soluble sugar content from 224.71 to 252.16 mM, the ABA content from 3.59 to 5.01 ng/(g FW), and the CK content from 4.01 to 4.56 ng/(g FW)- for the optimum growth and recover of P. euphratica indicated by the plant performance parameters, and the efficiency of water release was the highest.

  13. Response of garlic (Allium sativum L.) bolting and bulbing to temperature and photoperiod treatments.

    Science.gov (United States)

    Wu, Cuinan; Wang, Mengyi; Cheng, Zhihui; Meng, Huanwen

    2016-01-01

    This research was conducted to evaluate the effect of temperature and photoperiod treatments on the bolting and bulb formation of three local garlic cultivars (cvs) in two consecutive years. Naturally vernalized plants of cvs G107, G025 and G064 were transplanted into growth chambers and subjected to various combinations of temperature [T15/10, 15°C/10°C; T20/15, 20°C/15°C and T25/18, 25°C/18°C (day/night)] and photoperiod (L8, 8 h and L14,14 h) treatments. Plant growth, endogenous phytohormone and methyl jasmonate (MeJA) levels, along with the bolting and yield of garlic were evaluated. The experimental results from two consecutive years indicated that higher temperature (20°C or 25°C) and longer photoperiod (14 h) treatments significantly enhanced the garlic bolting, bulbing and cloving with a shorter growth period and a higher bulb weight. Moreover, the endogenous phytohormone and MeJA levels in the test plants were significantly increased by the higher temperature (25°C for the phytohormone level; 20°C for the MeJA level) and longer photoperiod [14 h, except for abscisic acid (ABA), which had the highest level at 8 h] conditions and were decreased by the lowest test temperature (15°C) and shorter photoperiod (8 h, except for ABA) conditions. This response coincided with that of the bulbing index, bolting rate, growth period and bulb weight. In addition, plants treated under the conditions of 20°C/15°C-14 h and 25°C/18°C-14 h produced the highest phytohormone levels (except for ABA) for cvs G025 and G064, respectively, and showed the best bolting and bulbing behavior. It is reasonable to assume that endogenous phytohormone (especially gibberellic acid) and MeJA levels are highly related to garlic bolting and bulbing, which might lead to the different responses of the three studied cultivars to the combination of temperature and photoperiod treatments. Furthermore, cvs G107 and G025 bolt well and have better bulb formation under 20

  14. Effects of Exogenous ABA on Accumulation of the Soluble Proteins and Dehydrins in Leaves of Ornamental Crabapples under Soil Drought Stress%干旱胁迫下外源ABA对观赏海棠叶片可溶性蛋白和脱水素积累的影响

    Institute of Scientific and Technical Information of China (English)

    胡玉净; 邓丽娟; 张杰; 沈红香; 姚允聪

    2012-01-01

    以抗旱性较强的观赏海棠品种‘王族’和抗旱性较弱的品种‘红丽’幼树为试材,采用“喷施ABA+干旱处理”和“喷水+干旱处理(对照)”2个处理组,测试不同干旱条件下ABA处理的观赏海棠叶片相对含水量(RWC)、相对电导率(REC)、可溶性蛋白含量(SPC)、可溶性蛋白和脱水素表达情况.结果显示:与对照相比,ABA处理的‘王族’叶片RWC显著升高,REC和SPC显著降低,而‘红丽’的相应指标变化则相反.SDS-PAGE分析表明:ABA处理分别引起了干旱处理过程中‘王族’叶片14.8,18.0,46.2,50.9,78.1,145.2 ku和‘红丽’叶片14.4,18.0,32.8,46.2,89.6,141.0 ku可溶性蛋白的变化.免疫蛋白印迹法测定结果表明:干旱处理分别诱导‘王族’叶片14.8,51.0 ku和‘红丽’叶片14 4,32.8 ku脱水素的积累;ABA处理显著地的诱导2品种叶片干旱处理开始时脱水素的积累,并降低干旱处理7天后‘王族’叶片14.8,51.0 ku和‘红丽’叶片14.4 ku的积累.ABA能够诱导正常水分条件下观赏海棠叶片脱水素的表达,但当植株处于干旱胁迫时,ABA抑制其叶片中被诱导的脱水素的积累,并且此抑制作用与品种间抗旱性呈正相关性.%In order to investigate the effects of ABA treatment on accumulation of the soluble proteins and dehydrins in leaves of ornamental crabapples under soil drought stress, we selected a drought resistance cultivar, Malus spp. cv. ' Royalty' and a drought susceptible cultivar,Malus spp. cv'Red Splendor' as plant materials, ABA solution or water (served as control) was sprayed on leaves of the plants subjected to soil drought. The relative water content (RWC) , relative electricity conductivity ( REC ) , soluble protein content ( SPC) , and the expression of soluble proteins and dehydrins in ornamental crabapples leaves were measured during the drought process. Our results indicated that for M. spp. cv. ' Royalty' leaves, pretreated with ABA RWC

  15. NAA和ABA处理对‘京优’葡萄花色苷生物合成相关基因表达的影响%Effects of NAA and ABA treatments on the expression of anthocyanin biosynthetic genes in 'Jing You' grape berry skin

    Institute of Scientific and Technical Information of China (English)

    周莉; 王军

    2011-01-01

    为人工调控花色苷合成,以‘京优’葡萄为实验材料,应用液相色谱-质谱(HPLC-MS)技术和荧光定量PCR,研究了萘乙酸(NAA)和脱落酸(ABA)处理对葡萄果皮花色苷积累及其生物合成相关基因表达的影响。结果表明:在‘京优’葡萄果皮中,可检测到16种花色苷;ABA处理的花色苷含量高于对照,NAA处理低于对照,并且ABA处理的果皮比对照和NAA多出3种花色苷;葡萄果实发育进入转色期,花色苷合成过程中类黄酮途径的结构基因上调表达,完熟后下调表达;ABA处理的果皮花色苷结构基因相对表达量高于对照,而NAA则低于对%In order to control anthocyanin synthesis of 'Jingyou' grape,we applied high performance liquid chromatography-mass spectrometry(HPLC-MS) and real time reverse transcription-polymerase chain reaction(RT-PCR) for studying the effects of naphthaleneacetic aicd(NAA) and abscisic acid(ABA) treatments on the accumulation of anthocyanins,as well as the expression of anthocyanin biosynthetic correlative genes.The results showed that there were 16 sorts of anthocyanins in 'Jing You' berry skin.The anthocyanin contents of ABA treatment were higher but NAA treatment lower than that of control.And there were three extra anthocyanins in ABA treatment of berry skin.The structural genes in flavonoid pathway of anthocyanin synthesis were up-regulated at veraison,but down-regulated after complete maturity.The expression of anthocyanin structural genes was higher in ABA treatment than control,but lower for NAA treatment than control.The accumulation of anthocyanin and the correlative genes of anthocyanin synthesis were promoted by exogenous ABA.And NAA treatment had the opposite impacts.

  16. Role of leaf hydraulic conductance in the regulation of stomatal conductance in almond and olive in response to water stress.

    Science.gov (United States)

    Hernandez-Santana, Virginia; Rodriguez-Dominguez, Celia M; Fernández, J Enrique; Diaz-Espejo, Antonio

    2016-06-01

    The decrease of stomatal conductance (gs) is one of the prime responses to water shortage and the main determinant of yield limitation in fruit trees. Understanding the mechanisms related to stomatal closure in response to imposed water stress is crucial for correct irrigation management. The loss of leaf hydraulic functioning is considered as one of the major factors triggering stomatal closure. Thus, we conducted an experiment to quantify the dehydration response of leaf hydraulic conductance (Kleaf) and its impact on gs in two Mediterranean fruit tree species, one deciduous (almond) and one evergreen (olive). Our hypothesis was that a higher Kleaf would be associated with a higher gs and that the reduction in Kleaf would predict the reduction in gs in both species. We measured Kleaf in olive and almond during a cycle of irrigation withholding. We also compared the results of two methods to measure Kleaf: dynamic rehydration kinetics and evaporative flux methods. In addition, determined gs, leaf water potential (Ψleaf), vein density, photosynthetic capacity and turgor loss point. Results showed that gs was higher in almond than in olive and so was Kleaf (Kmax = 4.70 and 3.42 mmol s(-1) MPa(-1) m(-2), in almond and olive, respectively) for Ψleaf > -1.2 MPa. At greater water stress levels than -1.2 MPa, however, Kleaf decreased exponentially, being similar for both species, while gs was still higher in almond than in olive. We conclude that although the Kleaf decrease with increasing water stress does not drive unequivocally the gs response to water stress, Kleaf is the variable most strongly related to the gs response to water stress, especially in olive. Other variables such as the increase in abscisic acid (ABA) may be playing an important role in gs regulation, although in our study the gs-ABA relationship did not show a clear pattern. PMID:26846979

  17. 拟南芥二氧化碳突变体生理特性的分析%Physiological Analysis of Two Arabidopsis thaliana Mutants in Response to CO2

    Institute of Scientific and Technical Information of China (English)

    宋玉伟; 陈家宝; 刘宗才

    2009-01-01

    [Objective] The purpose was to seek for the different phenotypes between wild type and Arabidopsis Mutants in response to CO2. [Method] The epidermis bioassays and seed germination test were carried out to analyze the physiological characteristics of two Arabidopsis mutants and their wild type. [Result] There existed distinct differences in stomata apertures, water loss and leaf temperature compared with wild type except for stomata density. In addition, seed germination test on the medium indicated that cdi1 was insensitive to ABA, mannitol and NaCl, but cds1 performed contrary to cdi1. [Conclusion] There are some different physiological characteristics between wild type and mutants.

  18. Order-disorder in In3+ perovskites: The example of A(In2/3B''1/3)O3 (A=Ba, Sr; B''=W, U)

    International Nuclear Information System (INIS)

    We describe the preparation and structural characterization of four In-containing perovskites from neutron powder diffraction (NPD) and X-ray powder diffraction (XRPD) data. Sr3In2B''O9 and Ba(In2/3B''1/3)O3 (B''=W, U) were synthesized by standard ceramic procedures. The crystal structure of the W-containing perovskites and Ba(In2/3U1/3)O3 have been revisited based on our high-resolution NPD and XRPD data, while for the new U-containing perovskite Sr3In2UO9 the structural refinement was carried out from high-resolution XRPD data. At room temperature, the crystal structure for the two Sr phases is monoclinic, space group P21/n, where the In atoms occupy two different sites Sr2[In]2d[In1/3B''2/3]2cO6, with a=5.7548(2) A, b=5.7706(2) A, c=8.1432(3) A, β=90.01(1)o for B''=W and a=5.861(1) A, b=5.908(1) A, c=8.315(2) A, β=89.98(1)o for B''=U. The two phases with A=Ba should be described in a simple cubic perovskite unit cell (S.G. Pm3-bar m) with In and B'' distributed at random at the octahedral sites, with a=4.16111(1) A and 4.24941(1) A for W and U compounds, respectively. - Graphical abstract: The structure of the new uranium-based double perovskite Sr3In2UO9 is described and the true symmetry of the other title compounds are revisited. The presence of long-range ordering in the Sr samples, by contrast with the Ba perovskites, is related with the smaller unit cell and B-B distances in the Sr oxides, promoting the electrostatic repulsions between highly charged W6+ and U6+ cations as driving force for the long-range B-site ordering

  19. Corporate Responsibility

    OpenAIRE

    World Bank

    2004-01-01

    Appeals to corporate responsibility often simply take for granted that businesses have ethical responsibilities that go beyond just respecting the law. This paper addresses arguments to the effect that businesses have no such responsibilities. The interesting claim is not that businesses have no ethical responsibility at all but that their primal responsibility is to increase their profits. The extent to which there is reason to take such arguments seriously delineates the limits of corporate...

  20. The Next Generation of ABA Providers.

    Science.gov (United States)

    Dixon, Mark R

    2014-10-01

    The imbalance of supply and demand for behavior analytic services will change in the near future. Behavior analysts, who want to survive in an increasing competitive marketplace, will need to show quality results and better results than the next behavior analyst. Trumpet Behavioral Health is a company designed to infuse scientific research with clinical practices. In the years ahead, look to companies like Trumpet as role models of the next generation of autism service providers. PMID:27471663

  1. Identification of gene modules associated with drought response in rice by network-based analysis.

    Directory of Open Access Journals (Sweden)

    Lida Zhang

    Full Text Available Understanding the molecular mechanisms that underlie plant responses to drought stress is challenging due to the complex interplay of numerous different genes. Here, we used network-based gene clustering to uncover the relationships between drought-responsive genes from large microarray datasets. We identified 2,607 rice genes that showed significant changes in gene expression under drought stress; 1,392 genes were highly intercorrelated to form 15 gene modules. These drought-responsive gene modules are biologically plausible, with enrichments for genes in common functional categories, stress response changes, tissue-specific expression and transcription factor binding sites. We observed that a gene module (referred to as module 4 consisting of 134 genes was significantly associated with drought response in both drought-tolerant and drought-sensitive rice varieties. This module is enriched for genes involved in controlling the response of the plant to water and embryonic development, including a heat shock transcription factor as the key regulator in the expression of ABRE-containing genes. These results suggest that module 4 is highly conserved in the ABA-mediated drought response pathway in different rice varieties. Moreover, our study showed that many hub genes clustered in rice chromosomes had significant associations with QTLs for drought stress tolerance. The relationship between hub gene clusters and drought tolerance QTLs may provide a key to understand the genetic basis of drought tolerance in rice.

  2. The 6-phosphogluconate Dehydrogenase Genes Are Responsive to Abiotic Stresses in Rice