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Sample records for arabidopsis delays leaf

  1. Leaf Downward Curvature and Delayed Flowering Caused by AtLH Overexpression in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    WUHao; YULin; TANGXiang-Rong; SHENRui-Juan; HEYu-Ke

    2004-01-01

    AtLHgene of Arabidopsis is a BcpLH(leafy head) homolog of Chinese cabbage, which encodes a double-stranded RNA-binding protein related to the curvature of folding leaf leading to the formation of leafy head. In order to elucidate the regulatory function of AtLH in the development of leaf curvature, we made a construct of 35S::AtLHand transformed it to Arabidopsis. In transgenic plants for sense-AtLH, transcripts of AtLH gene were increased significantly in leaves and flowers, giving rise to the AtLH-overexpressed plants in which the rosette leaves curved downward or outward in a manner of enhanced epinastic growth. Compared with normal plants, bolting and flowering time of the transgenic plants was significantly delayed. Moreover, the apical dominance of transgenic plants was weaker in vegetative shoots since more axillary shoots emerged from axil of rosette leaves, while stronger in flowering shoots because fewer cauline inflorescences were observed on the main inflorescence. In other aspects, these transgenic plants exhibited an increase in root-stimulating response to IAA and decrease in root-inhibitory reaction on ABA. It indicates that overexpression of AtLH causes downward curvature of transgenic plants.

  2. YUCCA6 over-expression demonstrates auxin function in delaying leaf senescence in Arabidopsis thaliana

    KAUST Repository

    Kim, Jeong Im

    2011-04-21

    The Arabidopsis thaliana YUCCA family of flavin monooxygenase proteins catalyses a rate-limiting step in de novo auxin biosynthesis. A YUCCA6 activation mutant, yuc6-1D, has been shown to contain an elevated free IAA level and to display typical high-auxin phenotypes. It is reported here that Arabidopsis plants over-expressing YUCCA6, such as the yuc6-1D activation mutant and 35S:YUC6 transgenic plants, displayed dramatic longevity. In addition, plants over-expressing YUCCA6 exhibited classical, delayed dark-induced and hormone-induced senescence in assays using detached rosette leaves. However, plants over-expressing an allele of YUCCA6, that carries mutations in the NADPH cofactor binding site, exhibited neither delayed leaf senescence phenotypes nor phenotypes typical of auxin overproduction. When the level of free IAA was reduced in yuc6-1D by conjugation to lysine, yuc6-1D leaves senesced at a rate similar to the wild-type leaves. Dark-induced senescence in detached leaves was accompanied by a decrease in their free IAA content, by the reduced expression of auxin biosynthesis enzymes such as YUCCA1 and YUCCA6 that increase cellular free IAA levels, and by the increased expression of auxin-conjugating enzymes encoded by the GH3 genes that reduce the cellular free auxin levels. Reduced transcript abundances of SAG12, NAC1, and NAC6 during senescence in yuc6-1D compared with the wild type suggested that auxin delays senescence by directly or indirectly regulating the expression of senescence-associated genes. 2011 The Author(s).

  3. Overexpression of Medicago sativa TMT elevates the α-tocopherol content in Arabidopsis seeds, alfalfa leaves, and delays dark-induced leaf senescence.

    Science.gov (United States)

    Jiang, Jishan; Jia, Huili; Feng, Guangyan; Wang, Zan; Li, Jun; Gao, Hongwen; Wang, Xuemin

    2016-08-01

    Alfalfa (Medicago sativa L.) is a major forage legume for livestock and a target for improving their dietary quality. Vitamin E is an essential vitamin that animals must obtain from their diet for proper growth and development. γ-tocopherol methyltransferase (γ-TMT), which catalyzes the conversion of δ- and γ-tocopherols (or tocotrienols) to β- and α-tocopherols (or tocotrienols), respectively, is the final enzyme involved in the vitamin E biosynthetic pathway. The overexpression of M. sativa L.'s γ-TMT (MsTMT) increased the α-tocopherol content 10-15 fold above that of wild type Arabidopsis seeds without altering the total content of vitamin E. Additionally, in response to osmotic stress, the biomass and the expression levels of several osmotic marker genes were significantly higher in the transgenic lines compared with wild type. Overexpression of MsTMT in alfalfa led to a modest, albeit significant, increase in α-tocopherol in leaves and was also responsible for a delayed leaf senescence phenotype. Additionally, the crude protein content was increased, while the acid and neutral detergent fiber contents were unchanged in these transgenic lines. Thus, increased α-tocopherol content occurred in transgenic alfalfa without compromising the nutritional qualities. The targeted metabolic engineering of vitamin E biosynthesis through MsTMT overexpression provides a promising approach to improve the α-tocopherol content of forage crops. PMID:27297993

  4. Hormonal Regulation of Leaf Morphogenesis in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Lin-Chuan Li; Ding-Ming Kang; Zhang-Liang Chen; Li-Jia Qu

    2007-01-01

    Leaf morphogenesis is strictly controlled not only by intrinsic genetic factors, such as transcriptional factors, but also by environmental cues, such as light, water and pathogens. Nevertheless, the molecular mechanism of how leaf rnorphogenesis is regulated by genetic programs and environmental cues is far from clear. Numerous series of events demonstrate that plant hormones, mostly small and simple molecules,play crucial roles in plant growth and development, and in responses of plants to environmental cues such as light. With more and more genetics and molecular evidence obtained from the model plant Arabidopsis,several fundamental aspects of leaf rnorphogenesis including the initiation of leaf primordia, the determination of leaf axes, the regulation of cell division and expansion in leaves have been gradually unveiled.Among these phytohormones, auxin is found to be essential in the regulation of leaf morphogenesis.

  5. Peach Leaf Senescence Delayed by Criconemella xenoplax

    OpenAIRE

    Nyczepir, A. P.; Wood, B. W.

    1988-01-01

    Fall annual leaf senescence of peach was delayed in the field and in microplots in the presence of Criconemella xenoplax. Soil from the rhizosphere of orchard trees with greener leaves had ca. 2.5 × more nematodes than soil around trees in a more advanced state of fall senescence. In microplots, monoclonal antibody enzyme immunoassay (EIA) of leaf cytokinins indicated that concentration of zeatin riboside-like substances and chlorophyll content were greater in leaves of trees growing in nemat...

  6. Ectopic Expression of BraYAB1-702, a Member of YABBY Gene Family in Chinese Cabbage, Causes Leaf Curling, Inhibition of Development of Shoot Apical Meristem and Flowering Stage Delaying in Arabidopsis thaliana

    OpenAIRE

    Lu-Gang Zhang; Jing Zhang; Ze-Ping Yang; Xin-Ling Zhang

    2013-01-01

    YABBY gene family plays an important role in the polarity development of lateral organs. We isolated the BraYAB1-702 gene, a member of the YABBY gene family, from young leaves of Chinese cabbage line 06J45. The full-length gene has a 937 bp CDNA sequence and contains an open reading frame (ORF) of 702 bp. The subcellular localization analysis showed that the expression product of the gene was localized in the nucleus. Ectopic expression of BraYAB1-702 in Arabidopsis thaliana caused leaf curli...

  7. A Journey Through a Leaf: Phenomics Analysis of Leaf Growth in Arabidopsis thaliana

    Science.gov (United States)

    Vanhaeren, Hannes; Gonzalez, Nathalie; Inzé, Dirk

    2015-01-01

    In Arabidopsis, leaves contribute to the largest part of the aboveground biomass. In these organs, light is captured and converted into chemical energy, which plants use to grow and complete their life cycle. Leaves emerge as a small pool of cells at the vegetative shoot apical meristem and develop into planar, complex organs through different interconnected cellular events. Over the last decade, numerous phenotyping techniques have been developed to visualize and quantify leaf size and growth, leading to the identification of numerous genes that contribute to the final size of leaves. In this review, we will start at the Arabidopsis rosette level and gradually zoom in from a macroscopic view on leaf growth to a microscopic and molecular view. Along this journey, we describe different techniques that have been key to identify important events during leaf development and discuss approaches that will further help unraveling the complex cellular and molecular mechanisms that underlie leaf growth. PMID:26217168

  8. Dysfunctional mitochondria regulate the size of root apical meristem and leaf development in Arabidopsis

    Science.gov (United States)

    Hsieh, Wei-Yu; Liao, Jo-Chien; Hsieh, Ming-Hsiun

    2015-01-01

    Mitochondria play an important role in maintaining metabolic and energy homeostasis in the plant cell. Thus, perturbation of mitochondrial structure and function will affect plant growth and development. Arabidopsis slow growth3 (slo3) is defective in At3g61360 that encodes a pentatricopeptide repeat (PPR) protein. Analysis of slo3 mitochondrial RNA metabolism revealed that the splicing of nad7 intron 2 is impaired, which leads to a dramatic reduction in complex I activity. So the SLO3 PPR protein is a splicing factor that is required for the removal of nad7 intron 2 in Arabidopsis. The slo3 mutant plants have obvious phenotypes with severe growth retardation and delayed development. The size of root apical meristem (RAM) is reduced and the production of meristem cells is decreased in slo3. Furthermore, the rosette leaves of slo3 are curled or crinkled, which may be derived from uneven growth of the leaf surface. The underlying mechanisms by which dysfunctional mitochondria affect these growth and developmental phenotypes have yet to be established. Nonetheless, plant hormone auxin is known to play an important role in orchestrating the development of RAM and leaf shape. It is possible that dysfunctional mitochondria may interact with auxin signaling pathways to regulate the boundary of RAM and the cell division arrest front during leaf growth in Arabidopsis. PMID:26237004

  9. Quantitative proteomics approaches to study leaf senescence in Arabidopsis thaliana

    OpenAIRE

    Hebeler, Romano

    2007-01-01

    Im Vergleich zu Arabidopsis thaliana Wildtyppflanzen zeigen onset of leaf death (old) Mutanten vorgezogene Blattseneszenz. Ziel der Arbeit war es, mittels relativ quantitativer Proteomics molekulare Prozesse der frühen Blattseneszenz zu analysieren. Zwei-dimensionale "difference gel electrophoresis" (DIGE) wurde eingesetzt, um Unterschiede in den Proteinkonzentrationen von A. thaliana mit normaler und veränderter Blattseneszenz zu bestimmen. Die regulierten Proteine wurden durc...

  10. Mutation of Oryza sativa CORONATINE INSENSITIVE 1b (OsCOI1b) delays leaf senescence

    Institute of Scientific and Technical Information of China (English)

    Sang-Hwa Lee; Yasuhito Sakuraba; Taeyoung Lee; Kyu-Won Kim; Gynheung An; Han Yong Lee; Nam-Chon Paek

    2015-01-01

    Jasmonic acid (JA) functions in plant development, including senescence and immunity. Arabidopsis thaliana CORONATINE INSENSITIVE 1 encodes a JA receptor and functions in the JA‐responsive signaling pathway. The Arabidopsis genome harbors a single COI gene, but the rice (Oryza sativa) genome harbors three COI homologs, OsCOI1a, OsCOI1b, and OsCOI2. Thus, it remains unclear whether each OsCOI has distinct, additive, synergistic, or redundant func-tions in development. Here, we use the oscoi1b‐1 knockout mutants to show that OsCOI1b mainly affects leaf senescence under senescence‐promoting conditions. oscoi1b‐1 mutants stayed green during dark‐induced and natural senescence, with substantial retention of chlorophylls and photosyn-thetic capacity. Furthermore, several senescence‐associated genes were downregulated in oscoi1b‐1 mutants, including homologs of Arabidopsis thaliana ETHYLENE INSENSITIVE 3 and ORESARA 1, important regulators of leaf senescence. These results suggest that crosstalk between JA signaling and ethylene signaling affects leaf senescence. The Arabidopsis coi1‐1 plants containing 35S:OsCOI1a or 35S:OsCOI1b rescued the delayed leaf senescence during dark incubation, sug-gesting that both OsCOI1a and OsCOI1b are required for promoting leaf senescence in rice. oscoi1b‐1 mutants showed significant decreases in spikelet fertility and grain weight, leading to severe reduction of grain yield, indicating that OsCOI1‐mediated JA signaling affects spikelet fertility and grain filling.

  11. Delayed leaf senescence induces extreme drought tolerance in crop plants

    OpenAIRE

    Rivero, Rosa; Peleg, Zvi; Szczerba, Mark; Tumimbang, Ellen; Jauregui, Rosa N; Liu, Li; Blumwald, Eduardo

    2009-01-01

    Drought, the most prominent threat to agricultural production worldwide, accelerates leaf senescence, leading to a decrease in canopy size, loss in photosynthesis and reduced yields. On the basis of the assumption that senescence is a type of cell death program that could be inappropriately activated during drought, we hypothesized that it may be possible to enhance drought tolerance by delaying drought-induced leaf senescence through the stress-induced synthesis of cytokinins. We generated m...

  12. Mutations in leaf starch metabolism modulate the diurnal root growth profiles of Arabidopsis thaliana

    OpenAIRE

    Yazdanbakhsh, Nima; FISAHN, JOACHIM

    2011-01-01

    Roots of Arabidopsis thaliana exhibit stable diurnal growth profiles that are controlled by the circadian clock. Here we describe the effects of mutations in leaf starch metabolism on the diurnal root growth characteristics of Arabidopsis thaliana. High temporal and spatial resolution video imaging was performed to quantify the growth kinetics of Arabidopsis wild-type as well as pgm, sex1, mex1, dpe1 and dpe2 starch metabolism mutants grown in three different photoperiods. As a result, root g...

  13. The cytokinin response factors modulate root and shoot growth and promote leaf senescence in Arabidopsis.

    Science.gov (United States)

    Raines, Tracy; Shanks, Carly; Cheng, Chia-Yi; McPherson, Duncan; Argueso, Cristiana T; Kim, Hyo J; Franco-Zorrilla, José M; López-Vidriero, Irene; Solano, Roberto; Vaňková, Radomíra; Schaller, G Eric; Kieber, Joseph J

    2016-01-01

    The cytokinin response factors (CRFs) are a group of related AP2/ERF transcription factors that are transcriptionally induced by cytokinin. Here we explore the role of the CRFs in Arabidopsis thaliana growth and development by analyzing lines with decreased and increased CRF function. While single crf mutations have no appreciable phenotypes, disruption of multiple CRFs results in larger rosettes, delayed leaf senescence, a smaller root apical meristem (RAM), reduced primary and lateral root growth, and, in etiolated seedlings, shorter hypocotyls. In contrast, overexpression of CRFs generally results in the opposite phenotypes. The crf1,2,5,6 quadruple mutant is embryo lethal, indicating that CRF function is essential for embryo development. Disruption of the CRFs results in partially insensitivity to cytokinin in a root elongation assay and affects the basal expression of a significant number of cytokinin-regulated genes, including the type-A ARRs, although it does not impair the cytokinin induction of the type-A ARRs. Genes encoding homeobox transcription factors are mis-expressed in the crf1,3,5,6 mutant, including STIMPY/WOX9 that is required for root and shoot apical meristem maintenance roots and which has previously been linked to cytokinin. These results indicate that the CRF transcription factors play important roles in multiple aspects of plant growth and development, in part through a complex interaction with cytokinin signaling. PMID:26662515

  14. Programming of Plant Leaf Senescence with Temporal and Inter-Organellar Coordination of Transcriptome in Arabidopsis.

    Science.gov (United States)

    Woo, Hye Ryun; Koo, Hee Jung; Kim, Jeongsik; Jeong, Hyobin; Yang, Jin Ok; Lee, Il Hwan; Jun, Ji Hyung; Choi, Seung Hee; Park, Su Jin; Kang, Byeongsoo; Kim, You Wang; Phee, Bong-Kwan; Kim, Jin Hee; Seo, Chaehwa; Park, Charny; Kim, Sang Cheol; Park, Seongjin; Lee, Byungwook; Lee, Sanghyuk; Hwang, Daehee; Nam, Hong Gil; Lim, Pyung Ok

    2016-05-01

    Plant leaves, harvesting light energy and fixing CO2, are a major source of foods on the earth. Leaves undergo developmental and physiological shifts during their lifespan, ending with senescence and death. We characterized the key regulatory features of the leaf transcriptome during aging by analyzing total- and small-RNA transcriptomes throughout the lifespan of Arabidopsis (Arabidopsis thaliana) leaves at multidimensions, including age, RNA-type, and organelle. Intriguingly, senescing leaves showed more coordinated temporal changes in transcriptomes than growing leaves, with sophisticated regulatory networks comprising transcription factors and diverse small regulatory RNAs. The chloroplast transcriptome, but not the mitochondrial transcriptome, showed major changes during leaf aging, with a strongly shared expression pattern of nuclear transcripts encoding chloroplast-targeted proteins. Thus, unlike animal aging, leaf senescence proceeds with tight temporal and distinct interorganellar coordination of various transcriptomes that would be critical for the highly regulated degeneration and nutrient recycling contributing to plant fitness and productivity. PMID:26966169

  15. The relationship between leaf area growth and biomass accumulation in Arabidopsis thaliana.

    Science.gov (United States)

    Weraduwage, Sarathi M; Chen, Jin; Anozie, Fransisca C; Morales, Alejandro; Weise, Sean E; Sharkey, Thomas D

    2015-01-01

    Leaf area growth determines the light interception capacity of a crop and is often used as a surrogate for plant growth in high-throughput phenotyping systems. The relationship between leaf area growth and growth in terms of mass will depend on how carbon is partitioned among new leaf area, leaf mass, root mass, reproduction, and respiration. A model of leaf area growth in terms of photosynthetic rate and carbon partitioning to different plant organs was developed and tested with Arabidopsis thaliana L. Heynh. ecotype Columbia (Col-0) and a mutant line, gigantea-2 (gi-2), which develops very large rosettes. Data obtained from growth analysis and gas exchange measurements was used to train a genetic programming algorithm to parameterize and test the above model. The relationship between leaf area and plant biomass was found to be non-linear and variable depending on carbon partitioning. The model output was sensitive to the rate of photosynthesis but more sensitive to the amount of carbon partitioned to growing thicker leaves. The large rosette size of gi-2 relative to that of Col-0 resulted from relatively small differences in partitioning to new leaf area vs. leaf thickness. PMID:25914696

  16. Individual Leaf Development in Arabidopsis thaliana: a Stable Thermal‐time‐based Programme

    OpenAIRE

    GRANIER, CHRISTINE; Massonnet, Catherine; TURC, OLIVIER; Muller, Bertrand; Chenu, Karine; Tardieu, François

    2002-01-01

    In crop species, the impact of temperature on plant development is classically modelled using thermal time. We examined whether this method could be used in a non‐crop species, Arabidopsis thaliana, to analyse the response to temperature of leaf initiation rate and of the development of two leaves of the rosette. The results confirmed the large plant‐to‐plant variability in the studied isogenic line of the Columbia ecotype: 100‐fold differences in leaf area among plants sown on the same date ...

  17. REVOLUTA and WRKY53 connect early and late leaf development in Arabidopsis

    DEFF Research Database (Denmark)

    Xie, Yakun; Huhn, Kerstin; Brandt, Ronny;

    2014-01-01

    As sessile organisms, plants have to continuously adjust growth and development to ever-changing environmental conditions. At the end of the growing season, annual plants induce leaf senescence to reallocate nutrients and energy-rich substances from the leaves to the maturing seeds. Thus, leaf...... that class III homeodomain leucine zipper (HD-ZIPIII) transcription factors, which are known to be involved in basic pattern formation, have an additional role in controlling the onset of leaf senescence in Arabidopsis. Several potential direct downstream genes of the HD-ZIPIII protein REVOLUTA (REV...... senescence is a means with which to increase reproductive success and is therefore tightly coupled to the developmental age of the plant. However, senescence can also be induced in response to sub-optimal growth conditions as an exit strategy, which is accompanied by severely reduced yield. Here, we show...

  18. Individual Leaf Development in Arabidopsis thaliana: a Stable Thermal‐time‐based Programme

    Science.gov (United States)

    GRANIER, CHRISTINE; MASSONNET, CATHERINE; TURC, OLIVIER; MULLER, BERTRAND; CHENU, KARINE; TARDIEU, FRANÇOIS

    2002-01-01

    In crop species, the impact of temperature on plant development is classically modelled using thermal time. We examined whether this method could be used in a non‐crop species, Arabidopsis thaliana, to analyse the response to temperature of leaf initiation rate and of the development of two leaves of the rosette. The results confirmed the large plant‐to‐plant variability in the studied isogenic line of the Columbia ecotype: 100‐fold differences in leaf area among plants sown on the same date were commonly observed at a given date. These differences disappeared in mature leaves, suggesting that they were due to a variability in plant developmental stage. The whole population could therefore be represented by any group of synchronous plants labelled at the two‐leaf stage and followed during their development. Leaf initiation rate, duration of leaf expansion and maximal relative leaf expansion rate varied considerably among experiments performed at different temperatures (from 6 to 26 °C) but they were linearly related to temperature in the range 6–26 °C, with a common x‐intercept of 3 °C. Expressing time in thermal time with a threshold temperature of 3 °C unified the time courses of leaf initiation and of individual leaf development for plants grown at different temperatures and experimental conditions. The two leaves studied (leaf 2 and leaf 6) had a two‐phase development, with an exponential phase followed by a phase with decreasing relative elongation rate. Both phases had constant durations for a given leaf position if expressed in thermal time. Changes in temperature caused changes in both the rate of development and in the expansion rate which mutually compensated such that they had no consequence on leaf area at a given thermal time. The resulting model of leaf development was applied to ten experiments carried out in a glasshouse or in a growth chamber, with plants grown in soil or hydroponically. Because it predicts accurately the stage

  19. Quantitative phenotyping of leaf margins in three dimensions, demonstrated on KNOTTED and TCP trangenics in Arabidopsis.

    Science.gov (United States)

    Armon, Shahaf; Yanai, Osnat; Ori, Naomi; Sharon, Eran

    2014-05-01

    The geometry of leaf margins is an important shape characteristic that distinguishes among different leaf phenotypes. Current definitions of leaf shape are qualitative and do not allow quantification of differences in shape between phenotypes. This is especially true for leaves with some non-trivial three-dimensional (3D) configurations. Here we present a novel geometrical method novel geometrical methods to define, measure, and quantify waviness and lobiness of leaves. The method is based on obtaining the curve of the leaf rim from a 3D surface measurement and decomposing its local curvature vector into the normal and geodesic components. We suggest that leaf waviness is associated with oscillating normal curvature along the margins, while lobiness is associated with oscillating geodesic curvature. We provide a way to integrate these local measures into global waviness and lobiness quantities. Using these novel definitions, we analysed the changes in leaf shape of two Arabidopsis genotypes, either as a function of gene mis-expression induction level or as a function of time. These definitions and experimental methods open the way for a more quantitative study of the shape of leaves and other growing slender organs. PMID:24706720

  20. Hydrogen isotope composition of leaf wax n-alkanes in Arabidopsis lines with different transpiration rates

    Science.gov (United States)

    Pedentchouk, N.; Lawson, T.; Eley, Y.; McAusland, L.

    2012-04-01

    Stable isotopic compositions of oxygen and hydrogen are used widely to investigate modern and ancient water cycles. The D/H composition of organic compounds derived from terrestrial plants has recently attracted significant attention as a proxy for palaeohydrology. However, the role of various plant physiological and biochemical factors in controlling the D/H signature of leaf wax lipids in extant plants remains unclear. The focus of this study is to investigate the effect of plant transpiration on the D/H composition of n-alkanes in terrestrial plants. This experiment includes 4 varieties of Arabidopsis thaliana that differ with respect to stomatal density and stomatal geometry. All 4 varieties were grown indoors under identical temperature, relative humidity, light and watering regimes and then sampled for leaf wax and leaf water stable isotopic measurements. During growth, stomatal conductance to carbon dioxide and water vapour were also determined. We found that the plants varied significantly in terms of their transpiration rates. Transpiration rates were significantly higher in Arabidopsis ost1 and ost1-1 varieties (2.4 and 3.2 mmol m-2 s-1, respectively) than in Arabidopsis RbohD and Col-0 (1.5 and 1.4). However, hydrogen isotope measurements of n-alkanes extracted from leaf waxes revealed a very different pattern. Varieties ost1, ost1-1, and RbohD have very similar deltaD values of n-C29 alkane (-125, -128, and -127 per mil), whereas the deltaD value of Col-0 is more negative (-137 per mil). The initial results of this work suggest that plant transpiration is decoupled from the D/H composition of n-alkanes. In other words, physical processes that affect water vapour movement between the plant and its environment apparently cannot account for the stable hydrogen isotope composition of organic compounds that comprise leaf waxes. Additional, perhaps biochemical, processes that affect hydrogen isotope fractionation during photosynthesis might need to be invoked

  1. In vivo packaging of triacylglycerols enhances Arabidopsis leaf biomass and energy density.

    Science.gov (United States)

    Winichayakul, Somrutai; Scott, Richard William; Roldan, Marissa; Hatier, Jean-Hugues Bertrand; Livingston, Sam; Cookson, Ruth; Curran, Amy Christina; Roberts, Nicholas John

    2013-06-01

    Our dependency on reduced carbon for energy has led to a rapid increase in the search for sustainable alternatives and a call to focus on energy densification and increasing biomass yields. In this study, we generated a uniquely stabilized plant structural protein (cysteine [Cys]-oleosin) that encapsulates triacylglycerol (TAG). When coexpressed with diacylglycerol O-acyltransferase (DGAT1) in Arabidopsis (Arabidopsis thaliana), we observed a 24% increase in the carbon dioxide (CO2) assimilation rate per unit of leaf area and a 50% increase in leaf biomass as well as approximately 2-, 3-, and 5-fold increases in the fatty acid content of the mature leaves, senescing leaves, and roots, respectively. We propose that the coexpression led to the formation of enduring lipid droplets that prevented the futile cycle of TAG biosynthesis/lipolysis and instead created a sustained demand for de novo lipid biosynthesis, which in turn elevated CO2 recycling in the chloroplast. Fatty acid profile analysis indicated that the formation of TAG involved acyl cycling in Arabidopsis leaves and roots. We also demonstrate that the combination of Cys-oleosin and DGAT1 resulted in the highest accumulation of fatty acids in the model single-cell eukaryote, Saccharomyces cerevisiae. Our results support the notion that the prevention of lipolysis is vital to enabling TAG accumulation in vegetative tissues and confirm the earlier speculation that elevating fatty acid biosynthesis in the leaf would lead to an increase in CO2 assimilation. The Cys-oleosins have applications in biofuels, animal feed, and human nutrition as well as in providing a tool for investigating fatty acid biosynthesis and catabolism. PMID:23616604

  2. Probing the reproducibility of leaf growth and molecular phenotypes: A comparison of three Arabidopsis accessions cultivated in ten laboratories

    OpenAIRE

    Massonnet, Catherine; Vile, Denis; Fabre, Juliette; Hannah, Matthew A; Caldana, C.; Lisec, J.; Beemster, G.T.S.; Meyer, R. C.; Messerli, G.; Gronlund, J.T.; Perkovic, J.; Wigmore, E.; May, S.; Bevan, M. W.; Meyer, Christian

    2010-01-01

    A major goal of the life sciences is to understand how molecular processes control phenotypes. Because understanding biological systems relies on the work of multiple laboratories, biologists implicitly assume that organisms with the same genotype will display similar phenotypes when grown in comparable conditions. We investigated to what extent this holds true for leaf growth variables and metabolite and transcriptome profiles of three Arabidopsis (Arabidopsis thaliana) genotypes grown in 10...

  3. Influence of atmospheric oxygen on leaf structure and starch deposition in Arabidopsis thaliana

    Science.gov (United States)

    Ramonell, K. M.; Kuang, A.; Porterfield, D. M.; Crispi, M. L.; Xiao, Y.; McClure, G.; Musgrave, M. E.

    2001-01-01

    Plant culture in oxygen concentrations below ambient is known to stimulate vegetative growth, but apart from reports on increased leaf number and weight, little is known about development at subambient oxygen concentrations. Arabidopsis thaliana (L.) Heynh. (cv. Columbia) plants were grown full term in pre-mixed atmospheres with oxygen partial pressures of 2.5, 5.1, 10.1, 16.2, and 21.3 kPa O2, 0.035 kPa CO2 and the balance nitrogen under continuous light. Fully expanded leaves were harvested and processed for light and transmission electron microscopy or for starch quantification. Growth in subambient oxygen concentrations caused changes in leaf anatomy (increased thickness, stomatal density and starch content) that have also been described for plants grown under carbon dioxide enrichment. However, at the lowest oxygen treatment (2.5 kPa), developmental changes occurred that could not be explained by changes in carbon budget caused by suppressed photorespiration, resulting in very thick leaves and a dwarf morphology. This study establishes the leaf parameters that change during growth under low O2, and identifies the lower concentration at which O2 limitation on transport and biosynthetic pathways detrimentally affects leaf development. Grant numbers: NAG5-3756, NAG2-1020, NAG2-1375.

  4. Hpa1 harpin needs nitroxyl terminus to promote vegetative growth and leaf photosynthesis in Arabidopsis

    Indian Academy of Sciences (India)

    Xiaojie Li; Liping Han; Yanying Zhao; Zhenzhen You; Chunling Zhang; Zhenzhen You; Hansong Dong; Chunling Zhang

    2014-03-01

    Hpa1 is a harpin protein produced by Xanthomonas oryzae, an important bacterial pathogen of rice, and has the growth-promoting activity in plants. To understand the molecular basis for the function of Hpa1, we generated an inactive variant protein, Hpa1NT, by deleting the nitroxyl-terminal region of the Hpa1 sequence and compared Hpa1NT with the full-length protein in terms of the effects on vegetative growth and related physiological responses in Arabidopsis. When Hpa1 was applied to plants, it acted to enhance the vegetative growth but did not affect the floral development. Enhanced plant growth was accompanied by induced expression of growth-promoting genes in plant leaves. The growth-promoting activity of Hpa1 was further correlated with a physiological consequence shown as promoted leaf photosynthesis as a result of facilitated CO2 conduction through leaf stomata and mesophyll cells. On the contrary, plant growth, growth-promoting gene expression, and the physiological consequence changed little in response to the Hpa1NT treatment. These analyses suggest that Hpa1 requires the nitroxyl-terminus to facilitate CO2 transport inside leaf cells and promote leaf photosynthesis and vegetative growth of the plant.

  5. The TORNADO1 and TORNADO2 genes function in several patterning processes during early leaf development in Arabidopsis thaliana

    OpenAIRE

    Cnops, Gerda; Neyt, Pia; Raes, Jeroen; Petrarulo, Marica; Nelissen, Hilde; Malenica, Nenad; Luschnig, Christian; Tietz, Olaf; Ditengou, Franck; Palme, Klaus; Azmi, Abdelkrim; Prinsen, Els; Van Lijsebettens, Maria

    2006-01-01

    In multicellular organisms, patterning is a process that generates axes in the primary body plan, creates domains upon organ formation, and finally leads to differentiation into tissues and cell types. We identified the Arabidopsis thaliana TORNADO1 (TRN1) and TRN2 genes and their role in leaf patterning processes such as lamina venation, symmetry, and lateral growth. In trn mutants, the leaf venation network had a severely reduced complexity: incomplete loops, no tertiary or quaternary veins...

  6. Defects in leaf epidermis of Arabidopsis thaliana plants with CDKA;1 activity reduced in the shoot apical meristem

    OpenAIRE

    Borowska-Wykret, Dorota; Elsner, Joanna; De Veylder, Lieven; Kwiatkowska, Dorota

    2012-01-01

    In Arabidopsis thaliana, like in other dicots, the shoot epidermis originates from protodermis, the outermost cell layer of shoot apical meristem. We examined leaf epidermis in transgenic A. thaliana plants in which CDKA;1.N146, a negative dominant allele of A-type cyclin-dependent kinase, was expressed from the SHOOTMERISTEMLESS promoter, i.e., in the shoot apical meristem. Using cleared whole mount preparations of expanding leaves and sequential in vivo replicas of expanding leaf surface, w...

  7. Delayed leaf senescence induces extreme drought tolerance in a flowering plant

    OpenAIRE

    Rivero, Rosa M.; Kojima, Mikiko; Gepstein, Amira; Sakakibara, Hitoshi; Mittler, Ron; Gepstein, Shimon; Blumwald, Eduardo

    2007-01-01

    Drought, the most prominent threat to agricultural production worldwide, accelerates leaf senescence, leading to a decrease in canopy size, loss in photosynthesis and reduced yields. On the basis of the assumption that senescence is a type of cell death program that could be inappropriately activated during drought, we hypothesized that it may be possible to enhance drought tolerance by delaying drought-induced leaf senescence. We generated transgenic plants expressing an isopentenyltransfera...

  8. The Arabidopsis Floral Repressor BFT DelaysFlowering by Competing with FT for FD Bindingunder High Salinity

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Soil salinity is one of the most serious agricultural problems that significantly reduce crop yields in the aridand semi-arid regions. It influences various phases of plant growth and developmental processes, such as seed germina-tion, leaf and stem growth, and reproductive propagation. Salt stress delays the onset of flowering in many plant spe-cies. We have previously reported that the Arabidopsis BROTHER OF FT AND TFL1 (BFT) acts as a floral repressor undersalt stress. However, the molecular mechanisms underlying the BFT function in the salt regulation of flowering inductionis unknown. In this work, we found that BFT delays flowering under high salinity by competing with FLOWERING LOCUST (FT) for binding to the FD transcription factor. The flowering time of FD-deficient fd-2 mutant was insensitive to highsalinity. BFT interacts with FD in the nucleus via the C-terminal domain of FD, which is also required for the interactionof FD with FT, and interferes with the FT-FD interaction. These observations indicate that BFT constitutes a distinct saltstress signaling pathway that modulates the function of the FT-FD module and possibly provides an adaptation strategythat fine-tunes photoperiodic flowering under high salinity.

  9. Effects of stomatal delays on the economics of leaf gas exchange under intermittent light regimes.

    Science.gov (United States)

    Vico, Giulia; Manzoni, Stefano; Palmroth, Sari; Katul, Gabriel

    2011-11-01

    • Understory plants are subjected to highly intermittent light availability and their leaf gas exchanges are mediated by delayed responses of stomata and leaf biochemistry to light fluctuations. In this article, the patterns in stomatal delays across biomes and plant functional types were studied and their effects on leaf carbon gains and water losses were quantified. • A database of more than 60 published datasets on stomatal responses to light fluctuations was assembled. To interpret these experimental observations, a leaf gas exchange model was developed and coupled to a novel formulation of stomatal movement energetics. The model was used to test whether stomatal delays optimize light capture for photosynthesis, whilst limiting transpiration and carbon costs for stomatal movement. • The data analysis showed that stomatal opening and closing delays occurred over a limited range of values and were strongly correlated. Plant functional type and climate were the most important drivers of stomatal delays, with faster responses in graminoids and species from dry climates. • Although perfectly tracking stomata would maximize photosynthesis and minimize transpiration at the expense of large opening costs, the observed combinations of opening and closure times appeared to be consistent with a near-optimal balance of carbon gain, water loss and movement costs. PMID:21851359

  10. Programming of Plant Leaf Senescence with Temporal and Inter-Organellar Coordination of Transcriptome in Arabidopsis1[OPEN

    Science.gov (United States)

    Koo, Hee Jung; Kim, Jeongsik; Jeong, Hyobin; Yang, Jin Ok; Lee, Il Hwan; Jun, Ji Hyung; Choi, Seung Hee; Park, Su Jin; Kang, Byeongsoo; Kim, You Wang; Phee, Bong-Kwan; Kim, Jin Hee; Seo, Chaehwa; Park, Charny; Kim, Sang Cheol; Park, Seongjin; Lee, Byungwook; Lee, Sanghyuk; Hwang, Daehee; Lim, Pyung Ok

    2016-01-01

    Plant leaves, harvesting light energy and fixing CO2, are a major source of foods on the earth. Leaves undergo developmental and physiological shifts during their lifespan, ending with senescence and death. We characterized the key regulatory features of the leaf transcriptome during aging by analyzing total- and small-RNA transcriptomes throughout the lifespan of Arabidopsis (Arabidopsis thaliana) leaves at multidimensions, including age, RNA-type, and organelle. Intriguingly, senescing leaves showed more coordinated temporal changes in transcriptomes than growing leaves, with sophisticated regulatory networks comprising transcription factors and diverse small regulatory RNAs. The chloroplast transcriptome, but not the mitochondrial transcriptome, showed major changes during leaf aging, with a strongly shared expression pattern of nuclear transcripts encoding chloroplast-targeted proteins. Thus, unlike animal aging, leaf senescence proceeds with tight temporal and distinct interorganellar coordination of various transcriptomes that would be critical for the highly regulated degeneration and nutrient recycling contributing to plant fitness and productivity. PMID:26966169

  11. Development-related PcG target in the apex 4 controls leaf margin architecture in Arabidopsis thaliana.

    Science.gov (United States)

    Engelhorn, Julia; Reimer, Julia J; Leuz, Iris; Göbel, Ulrike; Huettel, Bruno; Farrona, Sara; Turck, Franziska

    2012-07-01

    In a reverse genetics screen based on a group of genes enriched for development-related Polycomb group targets in the apex (DPAs), we isolated DPA4 as a novel regulator of leaf margin shape. T-DNA insertion lines in the DPA4 locus display enhanced leaf margin serrations and enlarged petals, whereas overexpression of DPA4 results in smooth margins. DPA4 encodes a putative RAV (Related to ABI3/VP1) transcriptional repressor and is expressed in the lateral organ boundary region and in the sinus of leaf serrations. DPA4 expression domains overlap with those of the known leaf shape regulator CUP-SHAPED COTYLEDON 2 (CUC2) and we provide evidence that DPA4 negatively regulates CUC2 expression independently of MIR164A, an established regulator of CUC2. Taken together, the data suggest DPA4 as a newly identified player in the signalling network that controls leaf serrations in Arabidopsis thaliana. PMID:22675210

  12. Chloroplast Dysfunction Causes Multiple Defects in Cell Cycle Progression in the Arabidopsis crumpled leaf Mutant

    KAUST Repository

    Hudik, Elodie

    2014-07-18

    The majority of research on cell cycle regulation is focused on the nuclear events that govern the replication and segregation of the genome between the two daughter cells. However, eukaryotic cells contain several compartmentalized organelles with specialized functions, and coordination among these organelles is required for proper cell cycle progression, as evidenced by the isolation of several mutants in which both organelle function and overall plant development were affected. To investigate how chloroplast dysfunction affects the cell cycle, we analyzed the crumpled leaf (crl) mutant of Arabidopsis (Arabidopsis thaliana), which is deficient for a chloroplastic protein and displays particularly severe developmental defects. In the crl mutant, we reveal that cell cycle regulation is altered drastically and that meristematic cells prematurely enter differentiation, leading to reduced plant stature and early endoreduplication in the leaves. This response is due to the repression of several key cell cycle regulators as well as constitutive activation of stress-response genes, among them the cell cycle inhibitor SIAMESE-RELATED5. One unique feature of the crl mutant is that it produces aplastidic cells in several organs, including the root tip. By investigating the consequence of the absence of plastids on cell cycle progression, we showed that nuclear DNA replication occurs in aplastidic cells in the root tip, which opens future research prospects regarding the dialogue between plastids and the nucleus during cell cycle regulation in higher plants.

  13. Putative sugarcane FT/TFL1 genes delay flowering time and alter reproductive architecture in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Carla P. Coelho

    2014-05-01

    Full Text Available Agriculturally important grasses such as rice, maize and sugarcane are evolutionarily distant from Arabidopsis, yet some components of the floral induction process are highly conserved. Flowering in sugarcane is an important factor that negatively affects cane yield and reduces sugar/ethanol production from this important perennial bioenergy crop. Comparative studies have facilitated the identification and characterization of putative orthologs of key flowering time genes in sugarcane, a complex polyploid plant whose genome has yet to be sequenced completely. Using this approach we identified phosphatidylethanolamine-binding protein (PEBP gene family members in sugarcane that are similar to the archetypical FT and TFL1 genes of Arabidopsis that play an essential role in controlling the transition from vegetative to reproductive growth. Expression analysis of ScTFL1, which falls into the TFL1-clade of floral repressors, showed transcripts in developing leaves surrounding the shoot apex but not at the apex itself. ScFT1 was detected in immature leaves and apical regions of vegetatively growing plants and, after the floral transition, expression also occurred in mature leaves. Ectopic over-expression of ScTFL1 in Arabidopsis caused delayed flowering in Arabidopsis, as might be expected for a gene related to TFL1. In addition, lines with the latest flowering phenotype exhibited aerial rosette formation. Unexpectedly, over-expression of ScFT1, which has greatest similarity to the florigen-encoding FT, also caused a delay in flowering. This preliminary analysis of divergent sugarcane FT and TFL1 gene family members from Saccharum spp. suggests that their expression patterns and roles in the floral transition has diverged from the predicted role of similar PEBP family members.

  14. The Thiol Reductase Activity of YUCCA6 Mediates Delayed Leaf Senescence by Regulating Genes Involved in Auxin Redistribution.

    Science.gov (United States)

    Cha, Joon-Yung; Kim, Mi R; Jung, In J; Kang, Sun B; Park, Hee J; Kim, Min G; Yun, Dae-Jin; Kim, Woe-Yeon

    2016-01-01

    Auxin, a phytohormone that affects almost every aspect of plant growth and development, is biosynthesized from tryptophan via the tryptamine, indole-3-acetamide, indole-3-pyruvic acid, and indole-3-acetaldoxime pathways. YUCCAs (YUCs), flavin monooxygenase enzymes, catalyze the conversion of indole-3-pyruvic acid (IPA) to the auxin (indole acetic acid). Arabidopsis thaliana YUC6 also exhibits thiol-reductase and chaperone activity in vitro; these activities require the highly conserved Cys-85 and are essential for scavenging of toxic reactive oxygen species (ROS) in the drought tolerance response. Here, we examined whether the YUC6 thiol reductase activity also participates in the delay in senescence observed in YUC6-overexpressing (YUC6-OX) plants. YUC6 overexpression delays leaf senescence in natural and dark-induced senescence conditions by reducing the expression of SENESCENCE-ASSOCIATED GENE 12 (SAG12). ROS accumulation normally occurs during senescence, but was not observed in the leaves of YUC6-OX plants; however, ROS accumulation was observed in YUC6-OX(C85S) plants, which overexpress a mutant YUC6 that lacks thiol reductase activity. We also found that YUC6-OX plants, but not YUC6-OX(C85S) plants, show upregulation of three genes encoding NADPH-dependent thioredoxin reductases (NTRA, NTRB, and NTRC), and GAMMA-GLUTAMYLCYSTEINE SYNTHETASE 1 (GSH1), encoding an enzyme involved in redox signaling. We further determined that excess ROS accumulation caused by methyl viologen treatment or decreased glutathione levels caused by buthionine sulfoximine treatment can decrease the levels of auxin efflux proteins such as PIN2-4. The expression of PINs is also reduced in YUC6-OX plants. These findings suggest that the thiol reductase activity of YUC6 may play an essential role in delaying senescence via the activation of genes involved in redox signaling and auxin availability. PMID:27242830

  15. Ectopic expression of the Arabidopsis transcriptional activator Athb-1 alters leaf cell fate in tobacco.

    Science.gov (United States)

    Aoyama, T; Dong, C H; Wu, Y; Carabelli, M; Sessa, G; Ruberti, I; Morelli, G; Chua, N H

    1995-11-01

    The Arabidopsis thaliana Athb-1 is a homeobox gene of unknown function. By analogy with homeobox genes of other organisms, its gene product, Athb-1, is most likely a transcription factor involved in developmental processes. We constructed a series of Athb-1-derived genes to examine the roles of Athb-1 in transcriptional regulation and plant development. Athb-1 was found to transactivate a promoter linked to a specific DNA binding site by transient expression assays. In transgenic tobacco plants, overexpression of Athb-1 or its chimeric derivatives with heterologous transactivating domains of the yeast transcription factor GAL4 or herpes simplex virus transcription factor VP16 conferred deetiolated phenotypes in the dark, including cotyledon expansion, true leaf development, and an inhibition of hypocotyl elongation. Expression of Athb-1 or the two chimeric derivatives also affected the development of palisade parenchyma under normal growth conditions, resulting in light green sectors in leaves and cotyledons, whereas other organs in the transgenic plants remained normal. Both developmental phenotypes were induced by glucocorticoid in transgenic plants expressing a chimeric transcription factor comprising the Athb-1 DNA binding domain, the VP16 transactivating domain, and the glucocorticoid receptor domain. Plants with severe inducible phenotypes showed additional abnormality in cotyledon expansion. Our results suggest that Athb-1 is a transcription activator involved in leaf development. PMID:8535134

  16. Repression of AS2 by WOX family transcription factors is required for leaf development in Medicago and Arabidopsis.

    Science.gov (United States)

    Zhang, Fei; Tadege, Million

    2015-01-01

    WOX transcription factors are key regulators of meristematic activity in plants. The Medicago WOX gene, STF, functions in maintenance of leaf marginal meristem, analogous to the function of WUS in the shoot apical meristem. Both STF and WUS directly repress AS2 expression in their respective domains. Ectopic expression of AS2 with WUS promoter leads to a narrow leaf phenotype and other phenotypes similar to the wus mutant. We also found that a wox1 prs wus triple mutant produces much narrower leaf blades than the wox1 prs double mutant, indicating that WUS genetically interacts with WOX1 and PRS in Arabidopsis leaf blade development. Our data points to a general requirement for AS2 repression in meristematic regions to allow cell proliferation. PMID:25807065

  17. Gradual shifts in sites of free-auxin production during leaf-primordium development and their role in vascular differentiation and leaf morphogenesis in Arabidopsis.

    Science.gov (United States)

    Aloni, Roni; Schwalm, Katja; Langhans, Markus; Ullrich, Cornelia I

    2003-03-01

    The major regulatory shoot signal is auxin, whose synthesis in young leaves has been a mystery. To test the leaf-venation hypothesis [R. Aloni (2001) J Plant Growth Regul 20: 22-34], the patterns of free-auxin production, movement and accumulation in developing leaf primordia of DR5::GUS-transformed Arabidopsis thaliana (L.) Heynh. were visualized. DR5::GUS expression was regarded to reflect sites of free auxin, while immunolocalization with specific monoclonal antibodies indicated total auxin distribution. The mRNA expression of key enzymes involved in the synthesis, conjugate hydrolysis, accumulation and basipetal transport of auxin, namely indole-3-glycerol-phosphate-synthase, nitrilase, IAA-amino acid hydrolase, chalcone synthase and PIN1 as an essential component of the basipetal IAA carrier, was investigated by reverse transcription-polymerase chain reaction. Near the shoot apex, stipules were the earliest sites of high free-auxin production. During early stages of primordium development, leaf apical dominance was evident from strong beta-glucuronidase activity in the elongating tip, possibly suppressing the production of free auxin in the leaf tissues below it. Hydathodes, which develop in the tip and later in the lobes, were apparently primary sites of high free-auxin production, the latter supported by auxin-conjugate hydrolysis, auxin retention by the chalcone synthase-dependent action of flavonoids and also by the PIN1-component of the carrier-mediated basipetal transport. Trichomes and mesophyll cells were secondary sites of free-auxin production. During primordium development there are gradual shifts in sites and concentrations of free-auxin production occurring first in the tip of a leaf primordium, then progressing basipetally along the margins, and finally appearing also in the central regions of the lamina. This developmental pattern of free-auxin production is suggested to control the basipetal maturation sequence of leaf development and vascular

  18. Arabidopsis plants grown in the field and climate chambers significantly differ in leaf morphology and photosystem components

    OpenAIRE

    Mishra Yogesh; Johansson Jänkänpää Hanna; Kiss Anett Z; Funk Christiane; Schröder Wolfgang P; Jansson Stefan

    2012-01-01

    Abstract Background Plants exhibit phenotypic plasticity and respond to differences in environmental conditions by acclimation. We have systematically compared leaves of Arabidopsis thaliana plants grown in the field and under controlled low, normal and high light conditions in the laboratory to determine their most prominent phenotypic differences. Results Compared to plants grown under field conditions, the "indoor plants" had larger leaves, modified leaf shapes and longer petioles. Their p...

  19. Starch synthase 4 is essential for coordination of starch granule formation with chloroplast division during Arabidopsis leaf expansion

    OpenAIRE

    Crumpton-Taylor, Matilda; Pike, Marilyn; Lu, Kuan-Jen; Hylton, Christopher M.; Feil, Regina; Eicke, Simona; Lunn, John E.; Zeeman, Samuel C.; Smith, Alison M.

    2013-01-01

    Arabidopsis thaliana mutants lacking the SS4 isoform of starch synthase have strongly reduced numbers of starch granules per chloroplast, suggesting that SS4 is necessary for the normal generation of starch granules. To establish whether it plays a direct role in this process, we investigated the circumstances in which granules are formed in ss4 mutants. Starch granule numbers and distribution and the accumulation of starch synthase substrates and products were investigated during ss4 leaf de...

  20. Selection of valine-resistance in callus culture of Arabidopsis thaliana (L.) Heynh. derived from leaf explants

    OpenAIRE

    Małgorzata D. Gaj; Grzegorz Czaja; Małgorzata Nawrot

    2014-01-01

    The selection of valine-resistant mutants was carried out in leaf explant cultures of three Arabidopsis thaliana (L.) Heynh. ecotypes: C-24, RLD and Columbia. The valine concentration used for in vitro selection, lethal for seed-growing plants, has not affected callus formation and growth. However, strong inhibition of shoot regeneration ability of calli growing under selection pressure was noticed. In total, 1043 explants were cultured on valine medium and 18 shoots were regenerated with an ...

  1. A crinkly leaf and delay flowering mutant of tobacco obtained from recoverable satellite-flown seeds

    Science.gov (United States)

    Cai, Liu-Ti; Zheng, Shao-Qing; Huang, Xue-Lin

    Dry seeds of Nicotiana tabacum (L) cv. K346 were flown with a recoverable satellite, the Chinese "Shen Zhou III" for 162 h. After spaceflight, a crinkly leaf and delay flowering mutant of tobacco ( T-cldf), which phenotype differed from the ground control (K346), was obtained from the seedlings after 48 d of the recoverable satellite-flown seeds germination. Major characteristics of T-cldf phenotype included crinkly leaf with outgrowth of the adaxial surface among the secondary veins and delay flowering. Amplified fragment length polymorphism (AFLP) analysis showed that five polymorphic bands were detected between T-cldf and ground control. The results suggested that recoverable satellite-flown condition could bring inheritable mutagenic effects on tobacco seeds and maybe used as a tool for accelerating the progress in tobacco breeding.

  2. A geographic cline in leaf salicylic acid with increasing elevation in Arabidopsis thaliana.

    Science.gov (United States)

    Zhang, Nana; Tonsor, Stephen J; Traw, M Brian

    2015-01-01

    Salicylic acid (SA) occupies a key role as a hormone central to both plant resistance to bacterial pathogens and tolerance of abiotic stresses. Plants at high elevation experience colder temperatures and elevated UV levels. While it has been predicted that SA concentrations will be higher in plants from high elevation populations, few studies have addressed this question. Here, we asked how concentrations of SA vary in natural populations of Arabidopsis thaliana collected across an elevational gradient on the Iberian Peninsula. In a series of common garden experiments, we found that constitutive SA concentrations were highest in genotypes from the low elevation populations. This result was in the opposite direction from our prediction and is an exception to the general finding that phenolic compounds increase with increasing elevation. These data suggest that high constitutive SA is not associated with resistance to cold temperatures in these plants. Furthermore, we also found that leaf constitutive camalexin concentrations, an important defense against some bacterial and fungal enemies, were highest in the low elevation populations, suggesting that pathogen pressures may be important. Further examination of this elevational cline will likely provide additional insights into the interplay between phenolic compounds and biotic and abiotic stress. PMID:25875692

  3. The microbiome of the leaf surface of Arabidopsis protects against a fungal pathogen.

    Science.gov (United States)

    Ritpitakphong, Unyarat; Falquet, Laurent; Vimoltust, Artit; Berger, Antoine; Métraux, Jean-Pierre; L'Haridon, Floriane

    2016-05-01

    We have explored the importance of the phyllosphere microbiome in plant resistance in the cuticle mutants bdg (BODYGUARD) or lacs2.3 (LONG CHAIN FATTY ACID SYNTHASE 2) that are strongly resistant to the fungal pathogen Botrytis cinerea. The study includes infection of plants under sterile conditions, 16S ribosomal DNA sequencing of the phyllosphere microbiome, and isolation and high coverage sequencing of bacteria from the phyllosphere. When inoculated under sterile conditions bdg became as susceptible as wild-type (WT) plants whereas lacs2.3 mutants retained the resistance. Adding washes of its phyllosphere microbiome could restore the resistance of bdg mutants, whereas the resistance of lacs2.3 results from endogenous mechanisms. The phyllosphere microbiome showed distinct populations in WT plants compared to cuticle mutants. One species identified as Pseudomonas sp isolated from the microbiome of bdg provided resistance to B. cinerea on Arabidopsis thaliana as well as on apple fruits. No direct activity was observed against B. cinerea and the action of the bacterium required the plant. Thus, microbes present on the plant surface contribute to the resistance to B. cinerea. These results open new perspectives on the function of the leaf microbiome in the protection of plants. PMID:26725246

  4. Genetic and histological studies on the delayed systemic movement of Tobacco Mosaic Virus in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Matus José

    2008-09-01

    Full Text Available Abstract Background Viral infections and their spread throughout a plant require numerous interactions between the host and the virus. While new functions of viral proteins involved in these processes have been revealed, current knowledge of host factors involved in the spread of a viral infection is still insufficient. In Arabidopsis thaliana, different ecotypes present varying susceptibilities to Tobacco mosaic virus strain U1 (TMV-U1. The rate of TMV-U1 systemic movement is delayed in ecotype Col-0 when compared with other 13 ecotypes. We followed viral movement through vascular tissue in Col-0 plants by electronic microscopy studies. In addition, the delay in systemic movement of TMV-U1 was genetically studied. Results TMV-U1 reaches apical leaves only after 18 days post rosette inoculation (dpi in Col-0, whereas it is detected at 9 dpi in the Uk-4 ecotype. Genetic crosses between Col-0 and Uk-4 ecotypes, followed by analysis of viral movement in F1 and F2 populations, revealed that this delayed movement correlates with a recessive, monogenic and nuclear locus. The use of selected polymorphic markers showed that this locus, denoted DSTM1 (Delayed Systemic Tobamovirus Movement 1, is positioned on the large arm of chromosome II. Electron microscopy studies following the virion's route in stems of Col-0 infected plants showed the presence of curved structures, instead of the typical rigid rods of TMV-U1. This was not observed in the case of TMV-U1 infection in Uk-4, where the observed virions have the typical rigid rod morphology. Conclusion The presence of defectively assembled virions observed by electron microscopy in vascular tissue of Col-0 infected plants correlates with a recessive delayed systemic movement trait of TMV-U1 in this ecotype.

  5. Dynamics of Jasmonate Metabolism upon Flowering and across Leaf Stress Responses in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Emilie Widemann

    2016-01-01

    Full Text Available The jasmonic acid (JA signaling pathway plays important roles in adaptation of plants to environmental cues and in specific steps of their development, particularly in reproduction. Recent advances in metabolic studies have highlighted intricate mechanisms that govern enzymatic conversions within the jasmonate family. Here we analyzed jasmonate profile changes upon Arabidopsis thaliana flower development and investigated the contribution of catabolic pathways that were known to turnover the active hormonal compound jasmonoyl-isoleucine (JA-Ile upon leaf stress. We report a rapid decline of JA-Ile upon flower opening, concomitant with the massive accumulation of its most oxidized catabolite, 12COOH-JA-Ile. Detailed genetic analysis identified CYP94C1 as the major player in this process. CYP94C1 is one out of three characterized cytochrome P450 enzymes that define an oxidative JA-Ile turnover pathway, besides a second, hydrolytic pathway represented by the amido-hydrolases IAR3 and ILL6. Expression studies combined with reporter gene analysis revealed the dominant expression of CYP94C1 in mature anthers, consistent with the established role of JA signaling in male fertility. Significant CYP94B1 expression was also evidenced in stamen filaments, but surprisingly, CYP94B1 deficiency was not associated with significant changes in JA profiles. Finally, we compared global flower JA profiles with those previously reported in leaves reacting to mechanical wounding or submitted to infection by the necrotrophic fungus Botrytis cinerea. These comparisons revealed distinct dynamics of JA accumulation and conversions in these three biological systems. Leaf injury boosts a strong and transient JA and JA-Ile accumulation that evolves rapidly into a profile dominated by ω-oxidized and/or Ile-conjugated derivatives. In contrast, B. cinerea-infected leaves contain mostly unconjugated jasmonates, about half of this content being ω-oxidized. Finally, developing

  6. Dynamics of Jasmonate Metabolism upon Flowering and across Leaf Stress Responses in Arabidopsis thaliana.

    Science.gov (United States)

    Widemann, Emilie; Smirnova, Ekaterina; Aubert, Yann; Miesch, Laurence; Heitz, Thierry

    2016-01-01

    The jasmonic acid (JA) signaling pathway plays important roles in adaptation of plants to environmental cues and in specific steps of their development, particularly in reproduction. Recent advances in metabolic studies have highlighted intricate mechanisms that govern enzymatic conversions within the jasmonate family. Here we analyzed jasmonate profile changes upon Arabidopsis thaliana flower development and investigated the contribution of catabolic pathways that were known to turnover the active hormonal compound jasmonoyl-isoleucine (JA-Ile) upon leaf stress. We report a rapid decline of JA-Ile upon flower opening, concomitant with the massive accumulation of its most oxidized catabolite, 12COOH-JA-Ile. Detailed genetic analysis identified CYP94C1 as the major player in this process. CYP94C1 is one out of three characterized cytochrome P450 enzymes that define an oxidative JA-Ile turnover pathway, besides a second, hydrolytic pathway represented by the amido-hydrolases IAR3 and ILL6. Expression studies combined with reporter gene analysis revealed the dominant expression of CYP94C1 in mature anthers, consistent with the established role of JA signaling in male fertility. Significant CYP94B1 expression was also evidenced in stamen filaments, but surprisingly, CYP94B1 deficiency was not associated with significant changes in JA profiles. Finally, we compared global flower JA profiles with those previously reported in leaves reacting to mechanical wounding or submitted to infection by the necrotrophic fungus Botrytis cinerea. These comparisons revealed distinct dynamics of JA accumulation and conversions in these three biological systems. Leaf injury boosts a strong and transient JA and JA-Ile accumulation that evolves rapidly into a profile dominated by ω-oxidized and/or Ile-conjugated derivatives. In contrast, B. cinerea-infected leaves contain mostly unconjugated jasmonates, about half of this content being ω-oxidized. Finally, developing flowers present an

  7. Ethylene-inhibiting compound 1-MCP delays leaf senescence in cotton plants under abiotic stress conditions

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuan; J T Cothren; CHEN De-hua; Amir M H Ibrahim; Leonardo Lombardini

    2015-01-01

    Cotton (Gossypium hirsutum L.) plants produce more ethylene when subjected to abiotic stresses, such as high temperatures and drought, which result in premature leaf senescence, reduced photosynthetic efifciency, and thus decreased yield. This study was conducted to test the hypothesis that the ethylene-inhibiting compound 1-methylcyclopropene (1-MCP) treatment of cotton plants can delay leaf senescence under high temperature, drought, and the aging process in control ed environ-mental conditions. Potted cotton plants were exposed to 1-MCP treatment at the early square stage of development. The protective effect of 1-MCP against membrane damage was found on older compared to younger leaves, indicating 1-MCP could lower the stress level caused by aging. Application of 1-MCP resulted in reduction of lipid peroxidation, membrane leakage, soluble sugar content, and increased chlorophyl content, in contrast to the untreated plants under heat stress, suggesting that 1-MCP treatment of cotton plants may also have the potential to reduce the effect of heat stress in terms of delayed senescence. Application of 1-MCP caused reductions of lipid peroxidation, membrane leakage, and soluble sugar content, together with increases in water use efifciency (WUE), water potential, chlorophyl content, and lfuorescence quantum efifciency, compared to the untreated plants under drought, suggesting that 1-MCP treatment of cotton plants may also have the ability to reduce the level of stress under drought conditions. In conclusion, 1-MCP treatment of cotton should have the potential to delay senescence under heat and drought stress, and the aging process. Additional y, 1-MCP is more effective under stress than under non-stress conditions.

  8. Induction of stromule formation by extracellular sucrose and glucose in epidermal leaf tissue of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Schattat Martin

    2011-08-01

    Full Text Available Abstract Background Stromules are dynamic tubular structures emerging from the surface of plastids that are filled with stroma. Despite considerable progress in understanding the importance of certain cytoskeleton elements and motor proteins for stromule maintenance, their function within the plant cell is still unknown. It has been suggested that stromules facilitate the exchange of metabolites and/or signals between plastids and other cell compartments by increasing the cytosolically exposed plastid surface area but experimental evidence for the involvement of stromules in metabolic processes is not available. The frequent occurrence of stromules in both sink tissues and heterotrophic cell cultures suggests that the presence of carbohydrates in the extracellular space is a possible trigger of stromule formation. We have examined this hypothesis with induction experiments using the upper epidermis from rosette leaves of Arabidopsis thaliana as a model system. Results We found that the stromule frequency rises significantly if either sucrose or glucose is applied to the apoplast by vacuum infiltration. In contrast, neither fructose nor sorbitol or mannitol are capable of inducing stromule formation which rules out the hypothesis that stromule induction is merely the result of changes in the osmotic conditions. Stromule formation depends on translational activity in the cytosol, whereas protein synthesis within the plastids is not required. Lastly, stromule induction is not restricted to the plastids of the upper epidermis but is similarly observed also with chloroplasts of the palisade parenchyma. Conclusions The establishment of an experimental system allowing the reproducible induction of stromules by vacuum infiltration of leaf tissue provides a suitable tool for the systematic analysis of conditions and requirements leading to the formation of these dynamic organelle structures. The applicability of the approach is demonstrated here by

  9. DELAYED FLOWERING, an Arabidopsis Gene That Acts in the Autonomous Flowering Promotion Pathway and Is Required for Normal Development

    Institute of Scientific and Technical Information of China (English)

    Ming-Jie Chen; Zheng Yuan; Hai Huang

    2006-01-01

    The control of flowering time in higher plants is one of the most important physiological processes and is critical for their reproductive success. To investigate the mechanisms controlling flowering time, we screened for Arabidopsis mutants with late-flowering phenotypes. One mutant, designated delayed flowering (dfr) in the Landsberg erecta (Ler) ecotype, was identified with delayed flowering time. Genetic analysis revealed that dfr is a single gene recessive nuclear mutant and the mutation was mapped to a locus tightly linked to UFO on chromosome 1. To our knowledge, no gene regulating flowering time has been reported yet in this region. The dfr mutant plant showed a delayed flowering time under the different growth conditions examined,including long- and short-day photoperiods and gibberellic acid GA3 treatments, suggesting that DFR is a gene involved in the autonomous flowering promotion pathway. The Arabidopsis gene FLOWERING LOCUS C (FLC) plays a central role in repressing flowering and its transcripts are undetectable in wild-type Ler.However, FLCexpression was upregulated in the dfrmutant, suggesting that DFR is a negative regulator of FLC. In addition, the dfr mutant plant displayed altered valve shapes of the silique and the number of trichomes and branches of each trichome were both reduced, indicating that the DRFgene is also required for normal plant development. Moreover, dfr leafy-5 (Ify-5) double mutant plants showed a much later flowering time than either dfr or Ify-5 single mutants, indicating that DFR and LFYact synergistically to promote flowering in Arabidopsis.

  10. High-contrast three-dimensional imaging of the Arabidopsis leaf enables the analysis of cell dimensions in the epidermis and mesophyll

    Directory of Open Access Journals (Sweden)

    Granier Christine

    2010-07-01

    Full Text Available Abstract Background Despite the wide spread application of confocal and multiphoton laser scanning microscopy in plant biology, leaf phenotype assessment still relies on two-dimensional imaging with a limited appreciation of the cells' structural context and an inherent inaccuracy of cell measurements. Here, a successful procedure for the three-dimensional imaging and analysis of plant leaves is presented. Results The procedure was developed based on a range of developmental stages, from leaf initiation to senescence, of soil-grown Arabidopsis thaliana (L. Heynh. Rigorous clearing of tissues, made possible by enhanced leaf permeability to clearing agents, allowed the optical sectioning of the entire leaf thickness by both confocal and multiphoton microscopy. The superior image quality, in resolution and contrast, obtained by the latter technique enabled the three-dimensional visualisation of leaf morphology at the individual cell level, cell segmentation and the construction of structural models. Image analysis macros were developed to measure leaf thickness and tissue proportions, as well as to determine for the epidermis and all layers of mesophyll tissue, cell density, volume, length and width. For mesophyll tissue, the proportion of intercellular spaces and the surface areas of cells were also estimated. The performance of the procedure was demonstrated for the expanding 6th leaf of the Arabidopsis rosette. Furthermore, it was proven to be effective for leaves of another dicotyledon, apple (Malus domestica Borkh., which has a very different cellular organisation. Conclusions The pipeline for the three-dimensional imaging and analysis of plant leaves provides the means to include variables on internal tissues in leaf growth studies and the assessment of leaf phenotypes. It also allows the visualisation and quantification of alterations in leaf structure alongside changes in leaf functioning observed under environmental constraints. Data

  11. Leaf Age-Dependent Photoprotective and Antioxidative Response Mechanisms to Paraquat-Induced Oxidative Stress in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Julietta Moustaka

    2015-06-01

    Full Text Available Exposure of Arabidopsis thaliana young and mature leaves to the herbicide paraquat (Pq resulted in a localized increase of hydrogen peroxide (H2O2 in the leaf veins and the neighboring mesophyll cells, but this increase was not similar in the two leaf types. Increased H2O2 production was concomitant with closed reaction centers (qP. Thirty min after Pq exposure despite the induction of the photoprotective mechanism of non-photochemical quenching (NPQ in mature leaves, H2O2 production was lower in young leaves mainly due to the higher increase activity of ascorbate peroxidase (APX. Later, 60 min after Pq exposure, the total antioxidant capacity of young leaves was not sufficient to scavenge the excess reactive oxygen species (ROS that were formed, and thus, a higher H2O2 accumulation in young leaves occurred. The energy allocation of absorbed light in photosystem II (PSII suggests the existence of a differential photoprotective regulatory mechanism in the two leaf types to the time-course Pq exposure accompanied by differential antioxidant protection mechanisms. It is concluded that tolerance to Pq-induced oxidative stress is related to the redox state of quinone A (QA.

  12. 3D fluorescent in situ hybridization using Arabidopsis leaf cryosections and isolated nuclei

    Directory of Open Access Journals (Sweden)

    Biot Eric

    2009-08-01

    Full Text Available Abstract Background Fluorescent hybridization techniques are widely used to study the functional organization of different compartments within the mammalian nucleus. However, few examples of such studies are known in the plant kingdom. Indeed, preservation of nuclei 3D structure, which is required for nuclear organization studies, is difficult to fulfill. Results We report a rapid protocol for fluorescent in situ hybridization (FISH performed on 3D isolated nuclei and thin cryosectioned leaves of Arabidopsis thaliana. The use of direct labeling minimized treatment steps, shortening the overall procedure. Using image analysis, we measured different parameters related to nucleus morphology and overall 3D structure. Conclusion Our work describes a 3D-FISH protocol that preserves the 3D structure of Arabidopsis interphase nuclei. Moreover, we report for the first time FISH using cryosections of Arabidopsis leaves. This protocol is a valuable tool to investigate nuclear architecture and chromatin organization.

  13. Ectopic expression of soybean GmKNT1 in Arabidopsis results in altered leaf morphology and flower identity

    Institute of Scientific and Technical Information of China (English)

    Jun Liu; Da Ha; Zongming Xie; Chunmei Wang; Huiwen Wang; Wanke Zhang; Jinsong Zhang; Shouyi Chen

    2008-01-01

    Plant morphology is specified by leaves and flowers, and the shoot apical meristem (SAM) defines the architecture of plant leaves and flowers. Here, we reported the characterization of a soybean KNOX gene GmKNT1, which was highly homologous to Arabidopsis STM. The GmKNT1 was strongly expressed in roots, flowers and developing seeds. Its expression could be induced by IAA, ABA and JA, but inhibited by GA or cytokinin. Staining of the transgenic plants overexpressing GmKNT1-GUS fusion protein revealed that the GmKNT1 was mainly expressed at lobe region, SAM of young leaves, sepal and carpel, not in seed and mature leaves. Scanning electron micros- copy (SEM) disclosed multiple changes in morphology of the epidermal cells and stigma. The transgenic Arabidopsis plants overexpress- ing the GmKNT1 showed small and lobed leaves, shortened internodes and small clustered inflorescence. The lobed leaves might result from the function of the meristems located at the boundary of the leaf. Compared with wild type plants, transgenic plants had higher ex- pression of the SAM-related genes including the CUP, WUS, CUC1, KNAT2 and KNAT6. These results indicated that the GmKNT1 could affect multiple aspects of plant growth and development by regulation of downstream genes expression.

  14. A geographic cline in leaf salicylic acid with increasing elevation in Arabidopsis thaliana

    OpenAIRE

    Zhang, Nana; Tonsor, Stephen J; Traw, M. Brian

    2015-01-01

    Salicylic acid (SA) occupies a key role as a hormone central to both plant resistance to bacterial pathogens and tolerance of abiotic stresses. Plants at high elevation experience colder temperatures and elevated UV levels. While it has been predicted that SA concentrations will be higher in plants from high elevation populations, few studies have addressed this question. Here, we asked how concentrations of SA vary in natural populations of Arabidopsis thaliana collected across an elevationa...

  15. The novel protein DELAYED PALE-GREENING1 is required for early chloroplast biogenesis in Arabidopsis thaliana.

    Science.gov (United States)

    Liu, Dong; Li, Weichun; Cheng, Jianfeng

    2016-01-01

    Chloroplast biogenesis is one of the most important subjects in plant biology. In this study, an Arabidopsis early chloroplast biogenesis mutant with a delayed pale-greening phenotype (dpg1) was isolated from a T-DNA insertion mutant collection. Both cotyledons and true leaves of dpg1 mutants were initially albino but gradually became pale green as the plant matured. Transmission electron microscopic observations revealed that the mutant displayed a delayed proplastid-to-chloroplast transition. Sequence and transcription analyses showed that AtDPG1 encodes a putatively chloroplast-localized protein containing three predicted transmembrane helices and that its expression depends on both light and developmental status. GUS staining for AtDPG1::GUS transgenic lines showed that this gene was widely expressed throughout the plant and that higher expression levels were predominantly found in green tissues during the early stages of Arabidopsis seedling development. Furthermore, quantitative real-time RT-PCR analyses revealed that a number of chloroplast- and nuclear-encoded genes involved in chlorophyll biosynthesis, photosynthesis and chloroplast development were substantially down-regulated in the dpg1 mutant. These data indicate that AtDPG1 plays an essential role in early chloroplast biogenesis, and its absence triggers chloroplast-to-nucleus retrograde signalling, which ultimately down-regulates the expression of nuclear genes encoding chloroplast-localized proteins. PMID:27160321

  16. Modulation of ethylene and heat-controlled hyponastic leaf movement in Arabidopsis thaliana by the plant defense hormones jasmonate and salicylate

    OpenAIRE

    van Zanten, Martijn; Ritsema, Tita; Polko, Joanna K.; Leon-Reyes, Antonio; Voesenek, Laurentius A C J; Frank F Millenaar; Pieterse, Corné M. J.; Peeters, Anton J. M.

    2012-01-01

    Upward leaf movement (hyponastic growth) is adopted by several plant species including Arabidopsis thaliana, as a mechanism to escape adverse growth conditions. Among the signals that trigger hyponastic growth are, the gaseous hormone ethylene, low light intensities, and supra-optimal temperatures (heat). Recent studies indicated that the defence-related phytohormones jasmonic acid (JA) and salicylic acid (SA) synthesized by the plant upon biotic infestation repress low light-induced hyponast...

  17. Improvements in the transformation of Arabidopsis thaliana C24 leaf-discs by Agrobacterium tumefaciens

    DEFF Research Database (Denmark)

    van der Graaff, Eric; Hooykaas, P J

    1996-01-01

    We report here an efficient Arabidopsis leafdisc transformation protocol yielding an average transformation frequency of 1.6 transgenic shoots per leaf explant 4 weeks after the bacterial infection period. Subsequent cultivation in vitro is such that a high percentage (85-90%) of the primary tran...... harboring an activator T-DNA construct in a gene tagging approach to isolate genes involved in morphogenesis and auxin signal transduction....

  18. A workflow for mathematical modeling of subcellular metabolic pathways in leaf metabolism of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Thomas eNägele

    2013-12-01

    Full Text Available During the last decade genome sequencing has experienced a rapid technological development resulting in numerous sequencing projects and applications in life science. In plant molecular biology, the availability of sequence data on whole genomes has enabled the reconstruction of metabolic networks. Enzymatic reactions are predicted by the sequence information. Pathways arise due to the participation of chemical compounds as substrates and products in these reactions. Although several of these comprehensive networks have been reconstructed for the genetic model plant Arabidopsis thaliana, the integration of experimental data is still challenging. Particularly the analysis of subcellular organization of plant cells limits the understanding of regulatory instances in these metabolic networks in vivo. In this study, we develop an approach for the functional integration of experimental high-throughput data into such large-scale networks. We present a subcellular metabolic network model comprising 524 metabolic intermediates and 548 metabolic interactions derived from a total of 2769 reactions. We demonstrate how to link the metabolite covariance matrix of different Arabidopsis thaliana accessions with the subcellular metabolic network model for the inverse calculation of the biochemical Jacobian, finally resulting in the calculation of a matrix which satisfies a Lyaponov equation involving a covariance matrix. In this way, differential strategies of metabolite compartmentation and involved reactions were identified in the accessions when exposed to low temperature.

  19. 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.

  20. Impacts of high ATP supply from chloroplasts and mitochondria on the leaf metabolism of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Chao eLiang

    2015-10-01

    Full Text Available Chloroplasts and mitochondria are the major ATP producing organelles in plant leaves. Arabidopsis thaliana purple acid phosphatase 2 (AtPAP2 is a phosphatase dually targeted to the outer membranes of both organelles and it plays a role in the import of selected nuclear-encoded proteins into these two organelles. Overexpression (OE of AtPAP2 in Arabidopsis thaliana accelerates plant growth and promotes flowering, seed yield and biomass at maturity. Measurement of ADP/ATP/NADP+/NADPH contents in the leaves of 20-day-old OE and wild-type lines at the end of night and at 1 and 8 h following illumination in a 16/8 h photoperiod revealed that the ATP levels and ATP/NADPH ratios were significantly increased in the OE line at all three time points. The AtPAP2 OE line is therefore a good model to investigate the impact of high energy on the global molecular status of Arabidopsis. In this study, transcriptome, proteome and metabolome profiles of the high ATP transgenic line were examined and compared with those of wild-type plants. A comparison of OE and WT at the end of the night provide valuable information on the impact of higher ATP output from mitochondria on plant physiology, as mitochondrial respiration is the major source of ATP in the dark in leaves. Similarly, comparison of OE and WT following illumination will provide information on the impact of higher energy output from chloroplasts on plant physiology. Overexpression of AtPAP2 was found to significantly affect the transcript and protein abundances of genes encoded by the two organellar genomes. For example, the protein abundances of many ribosomal proteins encoded by the chloroplast genome were higher in the AtPAP2 OE line under both light and dark conditions, while the protein abundances of multiple components of the photosynthetic complexes were lower. RNA-seq data also showed that the transcription of the mitochondrial genome is greatly affected by the availability of energy. These data

  1. Genome-wide analysis of the Arabidopsis leaf transcriptome reveals interaction of phosphate and sugar metabolism

    DEFF Research Database (Denmark)

    Muller, Renate; Morant, Marc; Jarmer, Hanne Østergaard;

    2007-01-01

    factors individually. The genes exhibiting interactions form three main clusters with different response patterns and functionality of genes. One cluster (cluster 1) most likely represents a regulatory program to support increased growth and development when both P and carbohydrates are ample. Another...... cluster (cluster 3) represents genes induced to alleviate P starvation and these are further induced by carbohydrate accumulation. Thus, interactions between P and Suc reveal two different signaling programs and novel interactions in gene regulation in response to environmental factors. cis......-Regulatory elements were analyzed for each factor and for interaction clusters. PHR1 binding sites were more frequent in promoters of P-regulated genes as compared to the entire Arabidopsis genome, and E2F and PHR1 binding sites were more frequent in interaction clusters 1 and 3, respectively....

  2. Changes in leaf proteome profile of Arabidopsis thaliana in response to salicylic acid

    Indian Academy of Sciences (India)

    Riddhi Datta; Ragini Sinha; Sharmila Chattopadhyay

    2013-06-01

    Salicylic acid (SA) has been implicated in determining the outcome of interactions between many plants and their pathogens. Global changes in response to this phytohormone have been observed at the transcript level, but little is known of how it induces changes in protein abundance. To this end we have investigated the effect of 1 mM SA on soluble proteins of Arabidopsis thaliana leaves by proteomic analysis. An initial study at transcript level has been performed on temporal landscape, which revealed that induction of most of the SA-responsive genes occurs within 3 to 6 h post treatment (HPT) and the expression peaked within 24 HPT. Two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF MS/MS analysis has been used to identify differentially expressed proteins and 63 spots have been identified successfully. This comparative proteomic profiling of SA treated leaves versus control leaves demonstrated the changes of many defence related proteins like pathogenesis related protein 10a (PR10a), disease-resistance-like protein, putative late blight-resistance protein, WRKY4, MYB4, etc. along with gross increase in the rate of energy production, while other general metabolism rate is slightly toned down, presumably signifying a transition from ‘normal mode’ to ‘defence mode’.

  3. Arabidopsis Type II Phosphatidylinositol 4-Kinase PI4Kγ5 Regulates Auxin Biosynthesis and Leaf Margin Development through Interacting with Membrane-Bound Transcription Factor ANAC078.

    Science.gov (United States)

    Tang, Yong; Zhao, Chun-Yan; Tan, Shu-Tang; Xue, Hong-Wei

    2016-08-01

    Normal leaf margin development is important for leaf morphogenesis and contributes to diverse leaf shapes in higher plants. We here show the crucial roles of an atypical type II phosphatidylinositol 4-kinase, PI4Kγ5, in Arabidopsis leaf margin development. PI4Kγ5 presents a dynamics expression pattern along with leaf development and a T-DNA mutant lacking PI4Kγ5, pi4kγ5-1, presents serrated leaves, which is resulted from the accelerated cell division and increased auxin concentration at serration tips. Studies revealed that PI4Kγ5 interacts with and phosphorylates a membrane-bound NAC transcription factor, ANAC078. Previous studies demonstrated that membrane-bound transcription factors regulate gene transcription by undergoing proteolytic process to translocate into nucleus, and ANAC078 undergoes proteolysis by cleaving off the transmembrane region and carboxyl terminal. Western blot analysis indeed showed that ANAC078 deleting of carboxyl terminal is significantly reduced in pi4kγ5-1, indicating that PI4Kγ5 is important for the cleavage of ANAC078. This is consistent with the subcellular localization observation showing that fluorescence by GFP-ANAC078 is detected at plasma membrane but not nucleus in pi4kγ5-1 mutant and that expression of ANAC078 deleting of carboxyl terminal, driven by PI4Kγ5 promoter, could rescue the leaf serration defects of pi4kγ5-1. Further analysis showed that ANAC078 suppresses the auxin synthesis by directly binding and regulating the expression of auxin synthesis-related genes. These results indicate that PI4Kγ5 interacts with ANAC078 to negatively regulate auxin synthesis and hence influences cell proliferation and leaf development, providing informative clues for the regulation of in situ auxin synthesis and cell division, as well as the cleavage and functional mechanism of membrane-bound transcription factors. PMID:27529511

  4. ELEVATED GROWTH CO2 DELAYS DROUGHT STRESS AND ACCELERATES RECOVERY OF RICE LEAF PHOTOSYNTHESIS.

    Science.gov (United States)

    Rice (Oryza sativa L. cv. IR-72) was grown season-long in sunlit, controlled-environment chambers at ambient and twice-ambient CO2 under continuous flooding, or drought imposed during panicle initiation and anthesis growth phases. At high CO2, leaf CO2 exchange rate (CER) and content of chlorophyll ...

  5. Detection system of acid rain pollution using light-induced delayed fluorescence of plant leaf in vivo

    Science.gov (United States)

    Zeng, Lizhang; Xing, Da

    2006-09-01

    Photosynthetic apparatus is susceptible to environmental stress. Light-induced delayed fluorescence (DF) in plant is an intrinsic label of the efficiency of charge separation at P680 in photosystem II (PS II). In this investigation, we have developed a biosensor that can accurately inspect acid rain pollution by means of DF in vivo. Compared with traditional methods, the proposed technique can continuously monitor environmental changes, making fast, real-time and noninvasive inspection possible. The biosensor is an all-weather measuring instrument; it has its own illumination power and utilizes intrinsic DF as the measurement marker. With soybean (Glycine max (L.) Merr.) seedling as a testing model, which is sensitive to acid rain pollution, the relationship that delayed fluorescence properties and capability of photosynthetic apparatus after being affected by simulated acid rain with different pH value was studied. The current investigation has revealed that the changes of delayed fluorescence (equation available in paper) can probably characterize the pollution degree of simulated acid rain, Inspecting the changes in DF characteristics (φ i) of plant leaf in vivo may be a new approach for the detection of acid rain pollution and its impact on the ecosystem.

  6. Regulated expression of a cytokinin biosynthesis gene IPT delays leaf senescence and improves yield under rainfed and irrigated conditions in canola (Brassica napus L..

    Directory of Open Access Journals (Sweden)

    Surya Kant

    Full Text Available Delay of leaf senescence through genetic modification can potentially improve crop yield, through maintenance of photosynthetically active leaves for a longer period. Plant growth hormones such as cytokinin regulate and delay leaf senescence. Here, the structural gene (IPT encoding the cytokinin biosynthetic enzyme isopentenyltransferase was fused to a functionally active fragment of the AtMYB32 promoter and was transformed into canola plants. Expression of the AtMYB32xs::IPT gene cassette delayed the leaf senescence in transgenic plants grown under controlled environment conditions and field experiments conducted for a single season at two geographic locations. The transgenic canola plants retained higher chlorophyll levels for an extended period and produced significantly higher seed yield with similar growth and phenology compared to wild type and null control plants under rainfed and irrigated treatments. The yield increase in transgenic plants was in the range of 16% to 23% and 7% to 16% under rainfed and irrigated conditions, respectively, compared to control plants. Most of the seed quality parameters in transgenic plants were similar, and with elevated oleic acid content in all transgenic lines and higher oil content and lower glucosinolate content in one specific transgenic line as compared to control plants. The results suggest that by delaying leaf senescence using the AtMYB32xs::IPT technology, productivity in crop plants can be improved under water stress and well-watered conditions.

  7. Overexpression of the Transcription Factors GmSHN1 and GmSHN9 Differentially Regulates Wax and Cutin Biosynthesis, Alters Cuticle Properties, and Changes Leaf Phenotypes in Arabidopsis.

    Science.gov (United States)

    Xu, Yangyang; Wu, Hanying; Zhao, Mingming; Wu, Wang; Xu, Yinong; Gu, Dan

    2016-01-01

    SHINE (SHN/WIN) clade proteins, transcription factors of the plant-specific APETALA 2/ethylene-responsive element binding factor (AP2/ERF) family, have been proven to be involved in wax and cutin biosynthesis. Glycine max is an important economic crop, but its molecular mechanism of wax biosynthesis is rarely characterized. In this study, 10 homologs of Arabidopsis SHN genes were identified from soybean. These homologs were different in gene structures and organ expression patterns. Constitutive expression of each of the soybean SHN genes in Arabidopsis led to different leaf phenotypes, as well as different levels of glossiness on leaf surfaces. Overexpression of GmSHN1 and GmSHN9 in Arabidopsis exhibited 7.8-fold and 9.9-fold up-regulation of leaf cuticle wax productions, respectively. C31 and C29 alkanes contributed most to the increased wax contents. Total cutin contents of leaves were increased 11.4-fold in GmSHN1 overexpressors and 5.7-fold in GmSHN9 overexpressors, mainly through increasing C16:0 di-OH and dioic acids. GmSHN1 and GmSHN9 also altered leaf cuticle membrane ultrastructure and increased water loss rate in transgenic Arabidopsis plants. Transcript levels of many wax and cutin biosynthesis and leaf development related genes were altered in GmSHN1 and GmSHN9 overexpressors. Overall, these results suggest that GmSHN1 and GmSHN9 may differentially regulate the leaf development process as well as wax and cutin biosynthesis. PMID:27110768

  8. Overexpression of the Transcription Factors GmSHN1 and GmSHN9 Differentially Regulates Wax and Cutin Biosynthesis, Alters Cuticle Properties, and Changes Leaf Phenotypes in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Yangyang Xu

    2016-04-01

    Full Text Available SHINE (SHN/WIN clade proteins, transcription factors of the plant-specific APETALA 2/ethylene-responsive element binding factor (AP2/ERF family, have been proven to be involved in wax and cutin biosynthesis. Glycine max is an important economic crop, but its molecular mechanism of wax biosynthesis is rarely characterized. In this study, 10 homologs of Arabidopsis SHN genes were identified from soybean. These homologs were different in gene structures and organ expression patterns. Constitutive expression of each of the soybean SHN genes in Arabidopsis led to different leaf phenotypes, as well as different levels of glossiness on leaf surfaces. Overexpression of GmSHN1 and GmSHN9 in Arabidopsis exhibited 7.8-fold and 9.9-fold up-regulation of leaf cuticle wax productions, respectively. C31 and C29 alkanes contributed most to the increased wax contents. Total cutin contents of leaves were increased 11.4-fold in GmSHN1 overexpressors and 5.7-fold in GmSHN9 overexpressors, mainly through increasing C16:0 di-OH and dioic acids. GmSHN1 and GmSHN9 also altered leaf cuticle membrane ultrastructure and increased water loss rate in transgenic Arabidopsis plants. Transcript levels of many wax and cutin biosynthesis and leaf development related genes were altered in GmSHN1 and GmSHN9 overexpressors. Overall, these results suggest that GmSHN1 and GmSHN9 may differentially regulate the leaf development process as well as wax and cutin biosynthesis.

  9. The intrinsically disordered protein LEA7 from Arabidopsis thaliana protects the isolated enzyme lactate dehydrogenase and enzymes in a soluble leaf proteome during freezing and drying.

    Science.gov (United States)

    Popova, Antoaneta V; Rausch, Saskia; Hundertmark, Michaela; Gibon, Yves; Hincha, Dirk K

    2015-10-01

    The accumulation of Late Embryogenesis Abundant (LEA) proteins in plants is associated with tolerance against stresses such as freezing and desiccation. Two main functions have been attributed to LEA proteins: membrane stabilization and enzyme protection. We have hypothesized previously that LEA7 from Arabidopsis thaliana may stabilize membranes because it interacts with liposomes in the dry state. Here we show that LEA7, contrary to this expectation, did not stabilize liposomes during drying and rehydration. Instead, it partially preserved the activity of the enzyme lactate dehydrogenase (LDH) during drying and freezing. Fourier-transform infrared (FTIR) spectroscopy showed no evidence of aggregation of LDH in the dry or rehydrated state under conditions that lead to complete loss of activity. To approximate the complex influence of intracellular conditions on the protective effects of a LEA protein in a convenient in-vitro assay, we measured the activity of two Arabidopsis enzymes (glucose-6-P dehydrogenase and ADP-glucose pyrophosphorylase) in total soluble leaf protein extract (Arabidopsis soluble proteome, ASP) after drying and rehydration or freezing and thawing. LEA7 partially preserved the activity of both enzymes under these conditions, suggesting its role as an enzyme protectant in vivo. Further FTIR analyses indicated the partial reversibility of protein aggregation in the dry ASP during rehydration. Similarly, aggregation in the dry ASP was strongly reduced by LEA7. In addition, mixtures of LEA7 with sucrose or verbascose reduced aggregation more than the single additives, presumably through the effects of the protein on the H-bonding network of the sugar glasses. PMID:25988244

  10. Decreased glycolate oxidase activity leads to altered carbon allocation and leaf senescence after a transfer from high CO2 to ambient air in Arabidopsis thaliana.

    Science.gov (United States)

    Dellero, Younès; Jossier, Mathieu; Glab, Nathalie; Oury, Céline; Tcherkez, Guillaume; Hodges, Michael

    2016-05-01

    Metabolic and physiological analyses of Arabidopsis thaliana glycolate oxidase (GOX) mutant leaves were performed to understand the development of the photorespiratory phenotype after transfer from high CO2 to air. We show that two Arabidopsis genes, GOX1 and GOX2, share a redundant photorespiratory role. Air-grown single gox1 and gox2 mutants grew normally and no significant differences in leaf metabolic levels and photosynthetic activities were found when compared with wild-type plants. To study the impact of a highly reduced GOX activity on plant metabolism, both GOX1 and GOX2 expression was knocked-down using an artificial miRNA strategy. Air-grown amiRgox1/2 plants with a residual 5% GOX activity exhibited a severe growth phenotype. When high-CO2-grown adult plants were transferred to air, the photosynthetic activity of amiRgox1/2 was rapidly reduced to 50% of control levels, and a high non-photochemical chlorophyll fluorescence quenching was maintained. (13)C-labeling revealed that daily assimilated carbon accumulated in glycolate, leading to reduced carbon allocation to sugars, organic acids, and amino acids. Such changes were not always mirrored in leaf total metabolite levels, since many soluble amino acids increased after transfer, while total soluble protein, RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase), and chlorophyll amounts decreased in amiRgox1/2 plants. The senescence marker, SAG12, was induced only in amiRgox1/2 rosettes after transfer to air. The expression of maize photorespiratory GOX in amiRgox1/2 abolished all observed phenotypes. The results indicate that the inhibition of the photorespiratory cycle negatively impacts photosynthesis, alters carbon allocation, and leads to early senescence in old rosette leaves. PMID:26896850

  11. Efeitos da radiação ultravioleta-B sobre a morfologia foliar de Arabidopsis thaliana (L. Heynh. (Brassicaceae Effects of ultraviolet-B radiation on leaf morphology of Arabidopsis thaliana (L. Heynh. (Brassicaceae

    Directory of Open Access Journals (Sweden)

    Maria Regina Torres Boeger

    2006-06-01

    Full Text Available A redução da camada de ozônio resulta no aumento da radiação ultravioleta que atinge a superfície terrestre, especialmente a radiação ultravioletaB (UV-B. O aumento da radiação poderá induzir a mudanças estruturais e fisiológicas nas plantas, influenciando no seu crescimento e desenvolvimento. O objetivo deste trabalho foi determinar os efeitos da radiação UV-B ambiente sobre a morfologia das folhas de Arabidopsis thaliana desenvolvidas em condições controladas. As sementes de A. thaliana cresceram em câmaras de crescimento, com 300 µmol m-2s-1 de radiação fotossinteticamente ativa (PAR com ou sem 6 kJ m-2 s-1 de radiação UV-Bbe (UV-Bbe; UV-B biologicamente efetiva. Após 21 dias, 10 folhas de cada tratamento (com e sem radiação UV-B foram coletadas para avaliar área foliar, massa fresca e seca, AEF, densidades estomáticas e de tricomas de ambas as faces da folha, espessura da lâmina foliar e concentração de compostos fenólicos e de clorofila total, a e b. As folhas tratadas com radiação UV-B apresentaram menor área foliar, massa fresca e seca, densidade de tricomas na face adaxial e densidade de estômatos na face abaxial da folha. Entretanto, apresentaram os maiores valores médios de espessura total da lâmina e do mesofilo, maior concentração de clorofila total, clorofila a e clorofila b e compostos fenólicos foliares do que as folhas não tratadas com radiação UV-B. Essas diferenças morfológicas significativas (p Reduction of the ozone layer results in the increase in ultraviolet radiation reaching the earth's surface, especially the ultraviolet-B (UV-B. The increase of radiation may induce structural and physiological changes in plants, influencing their growth and development. This paper evaluates the effects of ambient UV-B radiation upon to the leaf morphology of Arabidopsis thaliana developed under controlled conditions. The seeds of A. thaliana grown in environmental chamber, with 300 µmol m-2

  12. Repression of AS2 by WOX family transcription factors is required for leaf development in Medicago and Arabidopsis

    OpenAIRE

    Zhang, Fei; Tadege, Million

    2015-01-01

    WOX transcription factors are key regulators of meristematic activity in plants. The Medicago WOX gene, STF, functions in maintenance of leaf marginal meristem, analogous to the function of WUS in the shoot apical meristem. Both STF and WUS directly repress AS2 expression in their respective domains. Ectopic expression of AS2 with WUS promoter leads to a narrow leaf phenotype and other phenotypes similar to the wus mutant. We also found that a wox1 prs wus triple mutant produces much narrower...

  13. Nitric Oxide Deficiency Accelerates Chlorophyll Breakdown and Stability Loss of Thylakoid Membranes during Dark-Induced Leaf Senescence in Arabidopsis

    OpenAIRE

    Liu, Fang(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China); Guo, Fang-Qing

    2013-01-01

    Nitric oxide (NO) has been known to preserve the level of chlorophyll (Chl) during leaf senescence. However, the mechanism by which NO regulates Chl breakdown remains unknown. Here we report that NO negatively regulates the activities of Chl catabolic enzymes during dark-induced leaf senescence. The transcriptional levels of the major enzyme genes involving Chl breakdown pathway except for RED CHL CATABOLITE REDUCTASE (RCCR) were dramatically up-regulated during dark-induced Chl degradation i...

  14. A mutation in the cytosolic O-acetylserine (thiol lyase induces a genome-dependent early leaf death phenotype in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Schippers Jos HM

    2010-04-01

    Full Text Available Abstract Background Cysteine is a component in organic compounds including glutathione that have been implicated in the adaptation of plants to stresses. O-acetylserine (thiol lyase (OAS-TL catalyses the final step of cysteine biosynthesis. OAS-TL enzyme isoforms are localised in the cytoplasm, the plastids and mitochondria but the contribution of individual OAS-TL isoforms to plant sulphur metabolism has not yet been fully clarified. Results The seedling lethal phenotype of the Arabidopsis onset of leaf death3-1 (old3-1 mutant is due to a point mutation in the OAS-A1 gene, encoding the cytosolic OAS-TL. The mutation causes a single amino acid substitution from Gly162 to Glu162, abolishing old3-1 OAS-TL activity in vitro. The old3-1 mutation segregates as a monogenic semi-dominant trait when backcrossed to its wild type accession Landsberg erecta (Ler-0 and the Di-2 accession. Consistent with its semi-dominant behaviour, wild type Ler-0 plants transformed with the mutated old3-1 gene, displayed the early leaf death phenotype. However, the old3-1 mutation segregates in an 11:4:1 (wild type: semi-dominant: mutant ratio when backcrossed to the Colombia-0 and Wassilewskija accessions. Thus, the early leaf death phenotype depends on two semi-dominant loci. The second locus that determines the old3-1 early leaf death phenotype is referred to as odd-ler (for old3 determinant in the Ler accession and is located on chromosome 3. The early leaf death phenotype is temperature dependent and is associated with increased expression of defence-response and oxidative-stress marker genes. Independent of the presence of the odd-ler gene, OAS-A1 is involved in maintaining sulphur and thiol levels and is required for resistance against cadmium stress. Conclusions The cytosolic OAS-TL is involved in maintaining organic sulphur levels. The old3-1 mutation causes genome-dependent and independent phenotypes and uncovers a novel function for the mutated OAS-TL in cell

  15. Arabidopsis NRT1.5 Mediates the Suppression of Nitrate Starvation-Induced Leaf Senescence by Modulating Foliar Potassium Level.

    Science.gov (United States)

    Meng, Shuan; Peng, Jia-Shi; He, Ya-Ni; Zhang, Guo-Bin; Yi, Hong-Ying; Fu, Yan-Lei; Gong, Ji-Ming

    2016-03-01

    Nitrogen deficiency induces leaf senescence. However, whether or how nitrate might affect this process remains to be investigated. Here, we report an interesting finding that nitrate-instead of nitrogen-starvation induced early leaf senescence in nrt1.5 mutant, and present genetic and physiological data demonstrating that nitrate starvation-induced leaf senescence is suppressed by NRT1.5. NRT1.5 suppresses the senescence process dependent on its function from roots, but not the nitrate transport function. Further analyses using nrt1.5 single and nia1 nia2 nrt1.5-4 triple mutant showed a negative correlation between nitrate concentration and senescence rate in leaves. Moreover, when exposed to nitrate starvation, foliar potassium level decreased in nrt1.5, but adding potassium could essentially restore the early leaf senescence phenotype of nrt1.5 plants. Nitrate starvation also downregulated the expression of HAK5, RAP2.11, and ANN1 in nrt1.5 roots, and appeared to alter potassium level in xylem sap from nrt1.5. These data suggest that NRT1.5 likely perceives nitrate starvation-derived signals to prevent leaf senescence by facilitating foliar potassium accumulation. PMID:26732494

  16. CCR1, an enzyme required for lignin biosynthesis in Arabidopsis, mediates cell proliferation exit for leaf development

    DEFF Research Database (Denmark)

    Xue, Jingshi; Luo, Dexian; Xu, Deyang;

    2015-01-01

    After initiation, leaves first undergo rapid cell proliferation. During subsequent development, leaf cells gradually exit the proliferation phase and enter the expansion stage, following a basipetally ordered pattern starting at the leaf tip. The molecular mechanism directing this pattern of leaf...... intermediate in lignin biosynthesis. FeA is known to have antioxidant activity, and the levels of reactive oxygen species (ROS) in ccr1 were markedly reduced. We also characterized another double mutant in CAFFEIC ACID O-METHYLTRANSFERASE (comt) and CAFFEOYL CoA 3-O-METHYLTRANSFERASE (ccoaomt), in which the FeA...... level was dramatically reduced. Cell proliferation in comt ccoaomt leaves was decreased, accompanied by elevated ROS levels, and the mutant phenotypes were partially rescued by treatment with FeA or another antioxidant (N-acetyl-L-cysteine). Taken together, our results suggest that CCR1, FeA and ROS...

  17. Abscisic acid as an internal integrator of multiple physiological processes modulates leaf senescence onset in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Yuwei eSong

    2016-02-01

    Full Text Available Many studies have shown that exogenous abscisic acid (ABA promotes leaf abscission and senescence. However, owing to a lack of genetic evidence, ABA function in plant senescence has not been clearly defined. Here, two-leaf early-senescence mutants (eas that were screened by chlorophyll fluorescence imaging and named eas1-1 and eas1-2 showed high photosynthetic capacity in the early stage of plant growth compared with the wild type. Gene mapping showed that eas1-1 and eas1-2 are two novel ABA2 allelic mutants. Under unstressed conditions, the eas1 mutations caused plant dwarf, early germination, larger stomatal apertures, and early leaf senescence compared with those of the wild type. Flow cytometry assays showed that the cell apoptosis rate in eas1 mutant leaves was higher than that of the wild type after day 30. A significant increase in the transcript levels of several senescence-associated genes, especially SAG12, was observed in eas1 mutant plants in the early stage of plant growth. More importantly, ABA-activated calcium channel activity in plasma membrane and induced the increase of cytoplasmic calcium concentration in guard cells are suppressed due to the mutation of EAS1. In contrast, the eas1 mutants lost chlorophyll and ion leakage significant faster than in the wild type under treatment with calcium channel blocker. Hence, our results indicate that endogenous ABA level is an important factor controlling the onset of leaf senescence through Ca2+ signaling.

  18. Leaf Development

    OpenAIRE

    Tsukaya, Hirokazu

    2013-01-01

    Leaves are the most important organs for plants. Without leaves, plants cannot capture light energy or synthesize organic compounds via photosynthesis. Without leaves, plants would be unable perceive diverse environmental conditions, particularly those relating to light quality/quantity. Without leaves, plants would not be able to flower because all floral organs are modified leaves. Arabidopsis thaliana is a good model system for analyzing mechanisms of eudicotyledonous, simple-leaf developm...

  19. Global metabolic profiling of Arabidopsis Polyamine Oxidase 4 (AtPAO4 loss-of-function mutants exhibiting delayed dark-induced senescence

    Directory of Open Access Journals (Sweden)

    Miren Iranzu Sequera-Mutiozabal

    2016-02-01

    Full Text Available Early and more recent studies have suggested that some polyamines (PAs, and particularly spermine (Spm, exhibit anti-senescence properties in plants. In this work, we have investigated the role of Arabidopsis Polyamine Oxidase 4 (PAO4, encoding a PA back-conversion oxidase, during dark-induced senescence. Two independent PAO4 (pao4-1 and pao4-2 loss-of-function mutants have been found that accumulate 10-fold higher Spm, and this associated with delayed entry into senescence under dark conditions. Mechanisms underlying pao4 delayed senescence have been studied using global metabolic profiling by GC-TOF/MS. pao4 mutants exhibit constitutively higher levels of important metabolites involved in redox regulation, central metabolism and signaling that support a priming status against oxidative stress. During senescence, interactions between PAs and oxidative, sugar and nitrogen metabolism have been detected that additively contribute to delayed entry into senescence. Our results indicate the occurrence of metabolic interactions between PAs, particularly Spm, with cell oxidative balance and transport/biosynthesis of amino acids as a strategy to cope with oxidative damage produced during senescence.

  20. Determination of Inter-leaf Translocated Free Glyphosate in Arabidopsis thaliana using Liquid Chromatography Tandem Mass Spectrometry (LCMS/MS) after Derivatization with Fluorenylmethyloxycarbonyl Chloride (FMOC-Cl)

    KAUST Repository

    Raji, Misjudeen

    2014-02-03

    Glyphosate is a broad-spectrum herbicide widely used for eliminating weeds in crop fields. Its mode of action is believed to be via translocation from the source to the sink tissues where it then interferes with the activities of 5-enol-pyruvylshikimate-3-phosphate synthase (EPSPS). In this study, the translocation of glyphosate in the leaves of Arabidopsis thaliana was investigated using an HPLC-MS/MS method following derivatization of the secondary amino group in the analyte using N-(9-fluorenylmethoxycarbonyloxy) chloride. To eliminate the errant precipitation that occurred when the reagent and the analyte are mixed, optimization of this method was required. The method linearity has a correlation coefficient higher than 0.99 over the concentration range of 0.005-2 μM. The limits of detection and quantitation were estimated to be 0.002 μM and 0.008 μM respectively. The repeatability of the method (as%R.S.D) ranged from 10% to 13%. The presented method was employed for the determination of free glyphosate in young untreated leaves of the specimen plants after treating a single leaf and allowing it to stand for 12 hours.

  1. A genetic link between epigenetic repressor AS1-AS2 and a putative small subunit processome in leaf polarity establishment of Arabidopsis.

    Science.gov (United States)

    Matsumura, Yoko; Ohbayashi, Iwai; Takahashi, Hiro; Kojima, Shoko; Ishibashi, Nanako; Keta, Sumie; Nakagawa, Ayami; Hayashi, Rika; Saéz-Vásquez, Julio; Echeverria, Manuel; Sugiyama, Munetaka; Nakamura, Kenzo; Machida, Chiyoko; Machida, Yasunori

    2016-01-01

    Although the DEAD-box RNA helicase family is ubiquitous in eukaryotes, its developmental role remains unelucidated. Here, we report that cooperative action between the Arabidopsis nucleolar protein RH10, an ortholog of human DEAD-box RNA helicase DDX47, and the epigenetic repressor complex of ASYMMETRIC-LEAVES1 (AS1) and AS2 (AS1-AS2) is critical to repress abaxial (ventral) genes ETT/ARF3 and ARF4, which leads to adaxial (dorsal) development in leaf primordia at shoot apices. Double mutations of rh10-1 and as2 (or as1) synergistically up-regulated the abaxial genes, which generated abaxialized filamentous leaves with loss of the adaxial domain. DDX47 is part of the small subunit processome (SSUP) that mediates rRNA biogenesis. In rh10-1 we found various defects in SSUP-related events, such as: accumulation of 35S/33S rRNA precursors; reduction in the 18S/25S ratio; and nucleolar hypertrophy. Double mutants of as2 with mutations of genes that encode other candidate SSUP-related components such as nucleolin and putative rRNA methyltransferase exhibited similar synergistic defects caused by up-regulation of ETT/ARF3 and ARF4 These results suggest a tight link between putative SSUP and AS1-AS2 in repression of the abaxial-determining genes for cell fate decisions for adaxial development. PMID:27334696

  2. A genetic link between epigenetic repressor AS1-AS2 and a putative small subunit processome in leaf polarity establishment of Arabidopsis

    Directory of Open Access Journals (Sweden)

    Yoko Matsumura

    2016-07-01

    Full Text Available Although the DEAD-box RNA helicase family is ubiquitous in eukaryotes, its developmental role remains unelucidated. Here, we report that cooperative action between the Arabidopsis nucleolar protein RH10, an ortholog of human DEAD-box RNA helicase DDX47, and the epigenetic repressor complex of ASYMMETRIC-LEAVES1 (AS1 and AS2 (AS1-AS2 is critical to repress abaxial (ventral genes ETT/ARF3 and ARF4, which leads to adaxial (dorsal development in leaf primordia at shoot apices. Double mutations of rh10-1 and as2 (or as1 synergistically up-regulated the abaxial genes, which generated abaxialized filamentous leaves with loss of the adaxial domain. DDX47 is part of the small subunit processome (SSUP that mediates rRNA biogenesis. In rh10-1 we found various defects in SSUP-related events, such as: accumulation of 35S/33S rRNA precursors; reduction in the 18S/25S ratio; and nucleolar hypertrophy. Double mutants of as2 with mutations of genes that encode other candidate SSUP-related components such as nucleolin and putative rRNA methyltransferase exhibited similar synergistic defects caused by up-regulation of ETT/ARF3 and ARF4. These results suggest a tight link between putative SSUP and AS1-AS2 in repression of the abaxial-determining genes for cell fate decisions for adaxial development.

  3. The DOF transcription factor Dof5.1 influences leaf axial patterning by promoting Revoluta transcription in Arabidopsis

    KAUST Repository

    Kim, Hyungsae

    2010-10-05

    Dof proteins are transcription factors that have a conserved single zinc finger DNA-binding domain. In this study, we isolated an activation tagging mutant Dof5.1-D exhibiting an upward-curling leaf phenotype due to enhanced expression of the REV gene that is required for establishing adaxialabaxial polarity. Dof5.1-D plants also had reduced transcript levels for IAA6 and IAA19 genes, indicating an altered auxin biosynthesis in Dof5.1-D. An electrophoretic mobility shift assay using the Dof5.1 DNA-binding motif and the REV promoter region indicated that the DNA-binding domain of Dof5.1 binds to a TAAAGT motif located in the 5′-distal promoter region of the REV promoter. Further, transient and chromatin immunoprecipitation assays verified binding activity of the Dof5.1 DNA-binding motif with the REV promoter. Consistent with binding assays, constitutive over-expression of the Dof5.1 DNA-binding domain in wild-type plants caused a downward-curling phenotype, whereas crossing Dof5.1-D to a rev mutant reverted the upward-curling phenotype of the Dof5.1-D mutant leaf to the wild-type. These results suggest that the Dof5.1 protein directly binds to the REV promoter and thereby regulates adaxialabaxial polarity. © 2010 Blackwell Publishing Ltd.

  4. Expression of potato RNA-binding proteins StUBA2a/b and StUBA2c induces hypersensitive-like cell death and early leaf senescence in Arabidopsis.

    Science.gov (United States)

    Na, Jong-Kuk; Kim, Jae-Kwang; Kim, Dool-Yi; Assmann, Sarah M

    2015-07-01

    The Arabidopsis thaliana genome encodes three RNA-binding proteins (RBPs), UBP1-associated protein 2a (UBA2a), UBA2b, and UBA2c, that contain two RNA-recognition motif (RRM) domains. They play important roles in wounding response and leaf senescence, and are homologs of Vicia faba abscisic-acid-activated protein kinase-interacting protein 1 (VfAKIP1). The potato (Solanum tuberosum) genome encodes at least seven AKIP1-like RBPs. Here, two potato RBPs have been characterized, StUBA2a/b and StUBA2c, that are homologous to VfAKIP1 and Arabidopsis UBA2s. Transient expression of StUBA2s induced a hypersensitive-like cell death phenotype in tobacco leaves, and an RRM-domain deletion assay of StUBA2s revealed that the first RRM domain is crucial for the phenotype. Unlike overexpression of Arabidopsis UBA2s, constitutive expression of StUBA2a/b in Arabidopsis did not cause growth arrest and lethality at the young seedling stage, but induced early leaf senescence. This phenotype was associated with increased expression of defence- and senescence-associated genes, including pathogen-related genes (PR) and a senescence-associated gene (SAG13), and it was aggravated upon flowering and ultimately resulted in a shortened life cycle. Leaf senescence of StUBA2a/b Arabidopsis plants was enhanced under darkness and was accompanied by H2O2 accumulation and altered expression of autophagy-associated genes, which likely cause cellular damage and are proximate causes of the early leaf senescence. Expression of salicylic acid signalling and biosynthetic genes was also upregulated in StUBA2a/b plants. Consistent with the localization of UBA2s-GFPs and VfAKIP1-GFP, soluble-modified GFP-StUBA2s localized in the nucleus within nuclear speckles. StUBA2s potentially can be considered for transgenic approaches to induce potato shoot senescence, which is desirable at harvest. PMID:25944928

  5. The embryonic leaf identity gene FUSCA3 regulates vegetative phase transitions by negatively modulating ethylene-regulated gene expression in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Lumba Shelley

    2012-02-01

    Full Text Available Abstract Background The embryonic temporal regulator FUSCA3 (FUS3 plays major roles in the establishment of embryonic leaf identity and the regulation of developmental timing. Loss-of-function mutations of this B3 domain transcription factor result in replacement of cotyledons with leaves and precocious germination, whereas constitutive misexpression causes the conversion of leaves into cotyledon-like organs and delays vegetative and reproductive phase transitions. Results Herein we show that activation of FUS3 after germination dampens the expression of genes involved in the biosynthesis and response to the plant hormone ethylene, whereas a loss-of-function fus3 mutant shows many phenotypes consistent with increased ethylene signaling. This FUS3-dependent regulation of ethylene signaling also impinges on timing functions outside embryogenesis. Loss of FUS3 function results in accelerated vegetative phase change, and this is again partially dependent on functional ethylene signaling. This alteration in vegetative phase transition is dependent on both embryonic and vegetative FUS3 function, suggesting that this important transcriptional regulator controls both embryonic and vegetative developmental timing. Conclusion The results of this study indicate that the embryonic regulator FUS3 not only controls the embryonic-to-vegetative phase transition through hormonal (ABA/GA regulation but also functions postembryonically to delay vegetative phase transitions by negatively modulating ethylene-regulated gene expression.

  6. The Arabidopsis thaliana natriuretic peptide AtPNP-A is a systemic regulator of leaf dark respiration and signals via the phloem

    KAUST Repository

    Ruzvidzo, Oziniel

    2011-09-01

    Plant natriuretic peptides (PNPs) belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. Here we show that a recombinant Arabidopsis thaliana PNP (AtPNP-A) rapidly increased the rate of dark respiration in treated leaves after 5 min. In addition, we observed increases in lower leaves, and with a lag time of 10 min, the effect spread to the upper leaves and subsequently (after 15 min) to the opposite leaves. This response signature is indicative of phloem mobility of the signal, a hypothesis that was further strengthened by the fact that cold girdling, which affects phloem but not xylem or apoplastic processes, delayed the long distance AtPNP-A effect. We conclude that locally applied AtPNP-A can induce a phloem-mobile signal that rapidly modifies plant homeostasis in distal parts. © 2011 Elsevier GmbH.

  7. Levels of Arabidopsis thaliana leaf phosphatidic acids, phosphatidylserines, and most trienoate-containing polar lipid molecular species increase during the dark period of the diurnal cycle

    Directory of Open Access Journals (Sweden)

    Sara eMaatta

    2012-03-01

    Full Text Available Previous work has demonstrated that plant leaf polar lipid fatty acid composition varies during the diurnal (dark-light cycle. Fatty acid synthesis occurs primarily during the light, but fatty acid desaturation continues in the absence of light, resulting in polyunsaturated fatty acids reaching their highest levels toward the end of the dark period. In this work, Arabidopsis thaliana were grown at constant (21°C temperature with 12-h light and 12-h dark periods. Collision induced dissociation time-of-flight mass spectrometry demonstrated that 16:3 and 18:3 fatty acid content in membrane lipids of leaves are higher at the end of the dark than at the end of the light period, while 16:1, 16:2, 18:0, and 18:1 content are higher at the end of the light period. Lipid profiling of membrane galactolipids, phospholipids, and lysophospholipids by electrospray ionization triple quadrupole mass spectrometry indicated that the monogalactosyldiacylglycerol, phosphatidylglycerol, and phosphatidylcholine classes include molecular species whose levels are highest at end of the light period and others that are highest at the end of the dark period. The levels of phosphatidic acid and phosphatidylserine classes were higher at the end of the dark period, and molecular species within these classes either followed the class pattern or were not significantly changed in the diurnal cycle. Phospholipase D (PLD is a family of enzymes that hydrolyzes phospholipids to produce phosphatidic acid. Analysis of several PLD mutant lines suggests that PLDζ2 and possibly PLDα1 may contribute to diurnal cycling of phosphatidic acid. The polar lipid compositional changes are considered in relation to recent data that demonstrate phosphatidylcholine acyl editing.

  8. PD trafficking of potato leaf roll virus movement protein in Arabidopsis depends on site-specific protein phosphorylation

    Directory of Open Access Journals (Sweden)

    Katrin eLink

    2011-06-01

    Full Text Available Many plant viruses encode for specialised movement proteins (MP to facilitate passage of viral material to and through plasmodesmata (PD. To analyse intracellular trafficking of potato leaf roll virus (PLRV movement protein (MP17 we performed GFP fusion experiments with distinct deletion variants of MP17. These studies revealed that the C-terminus of MP17 is essential but not sufficient for PD targeting. Interestingly, fusion of GFP to three C-terminal MP17 deletion variants resulted in the accumulation of GFP in chloroplasts. This indicates that MP17 harbours hidden plastid targeting sequences. Previous studies showed that posttranslational protein phosphorylation influences PD targeting of MP and virus spread. Analysis of MP17-derived phospho-peptides by mass spectrometry revealed four phosphorylated serine residues (S71, S79, S137 and S140. Site-directed mutagenesis of S71/S79 and S137/S140 showed that the C-terminal serine residues S137/S140 are dispensable for PD targeting. However, exchange of S71/S79 to A71/A79 abolished PD targeting of the mutated MP17 protein. To mimic phosphorylation of S71/S79 both amino acids were substituted by aspartic acid. The resulting D71/D79 variant of MP17 was efficiently targeted to PD. Further deletion analysis showed that PD targeting of MP17 is dependent on the C-terminus, phosphorylation of S71 and/or S79 and a N-terminal domain.

  9. Growth at elevated CO2 delays the adverse effects of drought stress on leaf photosynthesis of the C4 sugarcane

    Science.gov (United States)

    Sugarcane was grown in sunlit greenhouses at 360 and 720 ppm CO2, and drought was imposed for 13 days on 4-month old plants. Leaf CO2 exchange rate (CER) and activity of Rubisco were marginally affected by high CO2 but were reduced by drought, whereas activity of PEP carboxylase was reduced by high ...

  10. Silencing of the CaCP Gene Delays Salt- and Osmotic-Induced Leaf Senescence in Capsicum annuum L.

    Directory of Open Access Journals (Sweden)

    Huai-Juan Xiao

    2014-05-01

    Full Text Available Cysteine proteinases have been known to participate in developmental processes and in response to stress in plants. Our present research reported that a novel CP gene, CaCP, was involved in leaf senescence in pepper (Capsicum annuum L.. The full-length CaCP cDNA is comprised of 1316 bp, contains 1044 nucleotides in open reading frame (ORF, and encodes a 347 amino acid protein. The deduced protein belongs to the papain-like cysteine proteases (CPs superfamily, containing a highly conserved ERFNIN motif, a GCNGG motif and a conserved catalytic triad. This protein localized to the vacuole of plant cells. Real-time quantitative PCR analysis revealed that the expression level of CaCP gene was dramatically higher in leaves and flowers than that in roots, stems and fruits. Moreover, CaCP transcripts were induced upon during leaf senescence. CaCP expression was upregulated by plant hormones, especially salicylic acid. CaCP was also significantly induced by abiotic and biotic stress treatments, including high salinity, mannitol and Phytophthora capsici. Loss of function of CaCP using the virus-induced gene-silencing technique in pepper plants led to enhanced tolerance to salt- and osmotic-induced stress. Taken together, these results suggest that CaCP is a senescence-associated gene, which is involved in developmental senescence and regulates salt- and osmotic-induced leaf senescence in pepper.

  11. Decrease in Leaf Sucrose Synthesis Leads to Increased Leaf Starch Turnover and Decreased RuBP-limited Photosynthesis But Not Rubisco-limited Photosynthesis in Arabidopsis Null Mutants of SPSA1

    Science.gov (United States)

    SPS (Sucrose phosphate synthase) isoforms from dicots cluster into families A, B and C. In this study, we investigated the individual effect of null mutations of each of the four SPS genes in Arabidopsis (spsa1, spsa2, spsb and spsc) on photosynthesis and carbon partitioning. Null mutants spsa1 and ...

  12. Activation tagging of the LEAFY PETIOLE gene affects leaf petiole development in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    van der Graaff, Eric; Dulk-Ras, A D; Hooykaas, P J;

    2000-01-01

    In a screen for leaf developmental mutants we have isolated an activator T-DNA-tagged mutant that produces leaves without a petiole. In addition to that leafy petiole phenotype this lettuce (let) mutant shows aberrant inflorescence branching and silique shape. The LEAFY PETIOLE (LEP) gene is...... located close to the right border of the T-DNA insert linked with these dominant phenotypes and encodes a protein with a domain with similarity to the DNA binding domain of members of the AP2/EREBP family of transcription factors. Introduction of the activation-tagged LEP gene in wild-type plants...... conferred all the phenotypic aberrations mentioned above. The leafy petiole phenotype consists of a conversion of the proximal part of the leaf from petiole into leaf blade, which means that leaf development in let is disturbed along the proximodistal axis. Therefore, LEP is involved in either cell division...

  13. A Dynamic Analysis of the Shade-induced Plasticity in Arabidopsis thaliana Rosette Leaf Development Reveals New Components of the Shade-adaptative Response

    OpenAIRE

    Cookson, Sarah Jane; Granier, Christine

    2006-01-01

    • Background and Aims It is well known that plant aerial development is affected by light intensity in terms of the date of flowering, the length of stems and petioles, and the final individual leaf area. The aim of the work presented here was to analyse how shade-induced changes in leaf development occur on a dynamic basis from the whole rosette level to that of the cells.

  14. Defects in leaf carbohydrate metabolism compromise acclimation to high light and lead to a high chlorophyll fluorescence phenotype in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Schmitz Jessica

    2012-01-01

    Full Text Available Abstract Background We have studied the impact of carbohydrate-starvation on the acclimation response to high light using Arabidopsis thaliana double mutants strongly impaired in the day- and night path of photoassimilate export from the chloroplast. A complete knock-out mutant of the triose phosphate/phosphate translocator (TPT; tpt-2 mutant was crossed to mutants defective in (i starch biosynthesis (adg1-1, pgm1 and pgi1-1; knock-outs of ADP-glucose pyrophosphorylase, plastidial phosphoglucomutase and phosphoglucose isomerase or (ii starch mobilization (sex1-3, knock-out of glucan water dikinase as well as in (iii maltose export from the chloroplast (mex1-2. Results All double mutants were viable and indistinguishable from the wild type when grown under low light conditions, but - except for sex1-3/tpt-2 - developed a high chlorophyll fluorescence (HCF phenotype and growth retardation when grown in high light. Immunoblots of thylakoid proteins, Blue-Native gel electrophoresis and chlorophyll fluorescence emission analyses at 77 Kelvin with the adg1-1/tpt-2 double mutant revealed that HCF was linked to a specific decrease in plastome-encoded core proteins of both photosystems (with the exception of the PSII component cytochrome b559, whereas nuclear-encoded antennae (LHCs accumulated normally, but were predominantly not attached to their photosystems. Uncoupled antennae are the major cause for HCF of dark-adapted plants. Feeding of sucrose or glucose to high light-grown adg1-1/tpt-2 plants rescued the HCF- and growth phenotypes. Elevated sugar levels induce the expression of the glucose-6-phosphate/phosphate translocator2 (GPT2, which in principle could compensate for the deficiency in the TPT. A triple mutant with an additional defect in GPT2 (adg1-1/tpt-2/gpt2-1 exhibited an identical rescue of the HCF- and growth phenotype in response to sugar feeding as the adg1-1/tpt-2 double mutant, indicating that this rescue is independent from the

  15. Easy Leaf Area: Automated Digital Image Analysis for Rapid and Accurate Measurement of Leaf Area

    OpenAIRE

    Hsien Ming Easlon; Bloom, Arnold J.

    2014-01-01

    Premise of the study: Measurement of leaf areas from digital photographs has traditionally required significant user input unless backgrounds are carefully masked. Easy Leaf Area was developed to batch process hundreds of Arabidopsis rosette images in minutes, removing background artifacts and saving results to a spreadsheet-ready CSV file. Methods and Results: Easy Leaf Area uses the color ratios of each pixel to distinguish leaves and calibration areas from their background and compares ...

  16. Leaf development: A cellular perspective

    Directory of Open Access Journals (Sweden)

    Gerrit TS Beemster

    2014-07-01

    Full Text Available Through its photosynthetic capacity the leaf provides the basis for growth of the whole plant. In order to improve crops for higher productivity and resistance for future climate scenarios, it is important to obtain a mechanistic understanding of leaf growth and development and the effect of genetic and environmental factors on the process. Cells are both the basic building blocks of the leaf and the regulatory units that integrate genetic and environmental information into the developmental program. Therefore, to fundamentally understand leaf development, one needs to be able to reconstruct the developmental pathway of individual cells (and their progeny from the stem cell niche to their final position in the mature leaf. To build the basis for such understanding, we review current knowledge on the spatial and temporal regulation mechanisms operating on cells, contributing to the formation of a leaf. We focus on the molecular networks that control exit from stem cell fate, leaf initiation, polarity, cytoplasmic growth, cell division, endoreduplication, transition between division and expansion, expansion and differentiation and their regulation by intercellular signaling molecules, including plant hormones, sugars, peptides, proteins and microRNAs. We discuss to what extent the knowledge available in the literature is suitable to be applied in systems biology approaches to model the process of leaf growth, in order to better understand and predict leaf growth starting with the model species Arabidopsis thaliana.

  17. Chloroplasts Are Central Players in Sugar-Induced Leaf Growth.

    Science.gov (United States)

    Van Dingenen, Judith; De Milde, Liesbeth; Vermeersch, Mattias; Maleux, Katrien; De Rycke, Riet; De Bruyne, Michiel; Storme, Véronique; Gonzalez, Nathalie; Dhondt, Stijn; Inzé, Dirk

    2016-05-01

    Leaves are the plant's powerhouses, providing energy for all organs through sugar production during photosynthesis. However, sugars serve not only as a metabolic energy source for sink tissues but also as signaling molecules, affecting gene expression through conserved signaling pathways to regulate plant growth and development. Here, we describe an in vitro experimental assay, allowing one to alter the sucrose (Suc) availability during early Arabidopsis (Arabidopsis thaliana) leaf development, with the aim to identify the affected cellular and molecular processes. The transfer of seedlings to Suc-containing medium showed a profound effect on leaf growth by stimulating cell proliferation and postponing the transition to cell expansion. Furthermore, rapidly after transfer to Suc, mesophyll cells contained fewer and smaller plastids, which are irregular in shape and contain fewer starch granules compared with control mesophyll cells. Short-term transcriptional responses after transfer to Suc revealed the repression of well-known sugar-responsive genes and multiple genes encoded by the plastid, on the one hand, and up-regulation of a GLUCOSE-6-PHOSPHATE TRANSPORTER (GPT2), on the other hand. Mutant gpt2 seedlings showed no stimulation of cell proliferation and no repression of chloroplast-encoded transcripts when transferred to Suc, suggesting that GPT2 plays a critical role in the Suc-mediated effects on early leaf growth. Our findings, therefore, suggest that induction of GPT2 expression by Suc increases the import of glucose-6-phosphate into the plastids that would repress chloroplast-encoded transcripts, restricting chloroplast differentiation. Retrograde signaling from the plastids would then delay the transition to cell expansion and stimulate cell proliferation. PMID:26932234

  18. The Arabidopsis synaptotagmin SYTA regulates the cell-to-cell movement of diverse plant viruses

    Directory of Open Access Journals (Sweden)

    Asako eUchiyama

    2014-11-01

    Full Text Available Synaptotagmins are a large gene family in animals that have been extensively characterized due to their role as calcium sensors to regulate synaptic vesicle exocytosis and endocytosis in neurons, and dense core vesicle exocytosis for hormone secretion from neuroendocrine cells. Thought to be exclusive to animals, synaptotagmins have recently been characterized in Arabidopsis thaliana, in which they comprise a five gene family. Using infectivity and leaf-based functional assays, we have shown that Arabidopsis SYTA regulates endocytosis and marks an endosomal vesicle recycling pathway to regulate movement protein-mediated trafficking of the Begomovirus Cabbage leaf curl virus (CaLCuV and the Tobamovirus Tobacco mosaic virus (TMV through plasmodesmata (Lewis and Lazarowitz, 2010. To determine whether SYTA has a central role in regulating the cell-to-cell trafficking of a wider range of diverse plant viruses, we extended our studies here to examine the role of SYTA in the cell-to-cell movement of additional plant viruses that employ different modes of movement, namely the Potyvirus Turnip mosaic virus (TuMV, the Caulimovirus Cauliflower mosaic virus (CaMV and the Tobamovirus Turnip vein clearing virus (TVCV, which in contrast to TMV does efficiently infect Arabidopsis. We found that both TuMV and TVCV systemic infection, and the cell-to-cell trafficking of the their movement proteins, were delayed in the Arabidopsis Col-0 syta-1 knockdown mutant. In contrast, CaMV systemic infection was not inhibited in syta-1. Our studies show that SYTA is a key regulator of plant virus intercellular movement, being necessary for the ability of diverse cell-to-cell movement proteins encoded by Begomoviruses (CaLCuV MP, Tobamoviruses (TVCV and TMV 30K protein and Potyviruses (TuMV P3N-PIPO to alter PD and thereby mediate virus cell-to-cell spread.

  19. Shotgun Proteomic Analysis of Arabidopsis thaliana Leaves

    Science.gov (United States)

    Two shotgun tandem mass spectrometry proteomics approaches, Multidimensional Protein Identification Technology (MudPIT) and 1D-Gel-LC-MS/MS, were used to identify Arabidopsis thaliana leaf proteins. These methods utilize different protein/peptide separation strategies. Detergents not compatible wit...

  20. Elucidating the role of transport processes in leaf glucosinolate distribution.

    Science.gov (United States)

    Madsen, Svend Roesen; Olsen, Carl Erik; Nour-Eldin, Hussam Hassan; Halkier, Barbara Ann

    2014-11-01

    In Arabidopsis (Arabidopsis thaliana), a strategy to defend its leaves against herbivores is to accumulate glucosinolates along the midrib and at the margin. Although it is generally assumed that glucosinolates are synthesized along the vasculature in an Arabidopsis leaf, thereby suggesting that the margin accumulation is established through transport, little is known about these transport processes. Here, we show through leaf apoplastic fluid analysis and glucosinolate feeding experiments that two glucosinolate transporters, GTR1 and GTR2, essential for long-distance transport of glucosinolates in Arabidopsis, also play key roles in glucosinolate allocation within a mature leaf by effectively importing apoplastically localized glucosinolates into appropriate cells. Detection of glucosinolates in root xylem sap unambiguously shows that this transport route is involved in root-to-shoot glucosinolate allocation. Detailed leaf dissections show that in the absence of GTR1 and GTR2 transport activity, glucosinolates accumulate predominantly in leaf margins and leaf tips. Furthermore, we show that glucosinolates accumulate in the leaf abaxial epidermis in a GTR-independent manner. Based on our results, we propose a model for how glucosinolates accumulate in the leaf margin and epidermis, which includes symplasmic movement through plasmodesmata, coupled with the activity of putative vacuolar glucosinolate importers in these peripheral cell layers. PMID:25209984

  1. LeafJ: an ImageJ plugin for semi-automated leaf shape measurement.

    Science.gov (United States)

    Maloof, Julin N; Nozue, Kazunari; Mumbach, Maxwell R; Palmer, Christine M

    2013-01-01

    High throughput phenotyping (phenomics) is a powerful tool for linking genes to their functions (see review and recent examples). Leaves are the primary photosynthetic organ, and their size and shape vary developmentally and environmentally within a plant. For these reasons studies on leaf morphology require measurement of multiple parameters from numerous leaves, which is best done by semi-automated phenomics tools. Canopy shade is an important environmental cue that affects plant architecture and life history; the suite of responses is collectively called the shade avoidance syndrome (SAS). Among SAS responses, shade induced leaf petiole elongation and changes in blade area are particularly useful as indices. To date, leaf shape programs (e.g. SHAPE, LAMINA, LeafAnalyzer, LEAFPROCESSOR) can measure leaf outlines and categorize leaf shapes, but can not output petiole length. Lack of large-scale measurement systems of leaf petioles has inhibited phenomics approaches to SAS research. In this paper, we describe a newly developed ImageJ plugin, called LeafJ, which can rapidly measure petiole length and leaf blade parameters of the model plant Arabidopsis thaliana. For the occasional leaf that required manual correction of the petiole/leaf blade boundary we used a touch-screen tablet. Further, leaf cell shape and leaf cell numbers are important determinants of leaf size. Separate from LeafJ we also present a protocol for using a touch-screen tablet for measuring cell shape, area, and size. Our leaf trait measurement system is not limited to shade-avoidance research and will accelerate leaf phenotyping of many mutants and screening plants by leaf phenotyping. PMID:23380664

  2. Antagonistic regulation of growth and immunity by the Arabidopsis basic helix-loop-helix transcription factor homolog of brassinosteroid enhanced expression2 interacting with increased leaf inclination1 binding bHLH1

    DEFF Research Database (Denmark)

    Malinovsky, Frederikke Gro; Batoux, Martine; Schwessinger, Benjamin;

    2014-01-01

    mechanisms is needed. Here, we identify the basic helix-loop-helix (bHLH) transcription factor homolog of brassinosteroid enhanced expression2 interacting with IBH1 (HBI1) as a negative regulator of PTI signaling in Arabidopsis (Arabidopsis thaliana). HBI1 expression is down-regulated in response to......Plants need to finely balance resources allocated to growth and immunity to achieve optimal fitness. A tradeoff between pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and brassinosteroid (BR)-mediated growth was recently reported, but more information about the underlying...

  3. Use of NAP gene to manipulate leaf senescence in plants

    Science.gov (United States)

    Gan, Susheng; Guo, Yongfeng

    2013-04-16

    The present invention discloses transgenic plants having an altered level of NAP protein compared to that of a non-transgenic plant, where the transgenic plants display an altered leaf senescence phenotype relative to a non-transgenic plant, as well as mutant plants comprising an inactivated NAP gene, where mutant plants display a delayed leaf senescence phenotype compared to that of a non-mutant plant. The present invention also discloses methods for delaying leaf senescence in a plant, as well as methods of making a mutant plant having a decreased level of NAP protein compared to that of a non-mutant plant, where the mutant plant displays a delayed leaf senescence phenotype relative to a non-mutant plant. Methods for causing precocious leaf senescence or promoting leaf senescence in a plant are also disclosed. Also disclosed are methods of identifying a candidate plant suitable for breeding that displays a delayed leaf senescence and/or enhanced yield phenotype.

  4. Phytohormones and microRNAs as sensors and regulators of leaf senescence: assigning macro roles to small molecules.

    Science.gov (United States)

    Sarwat, Maryam; Naqvi, Afsar Raza; Ahmad, Parvaiz; Ashraf, Muhammad; Akram, Nudrat Aisha

    2013-12-01

    Ageing or senescence is an intricate and highly synchronized developmental phase in the life of plant parts including leaf. Senescence not only means death of a plant part, but during this process, different macromolecules undergo degradation and the resulting components are transported to other parts of the plant. During the period from when a leaf is young and green to the stage when it senesces, a multitude of factors such as hormones, environmental factors and senescence associated genes (SAGs) are involved. Plant hormones including salicylic acid, abscisic acid, jasmonic acid and ethylene advance leaf senescence, whereas others like cytokinins, gibberellins, and auxins delay this process. The environmental factors which generally affect plant development and growth, can hasten senescence, the examples being nutrient dearth, water stress, pathogen attack, radiations, high temperature and light intensity, waterlogging, and air, water or soil contamination. Other important influences include carbohydrate accumulation and high carbon/nitrogen level. To date, although several genes involved in this complex process have been identified, still not much information exists in the literature on the signalling mechanism of leaf senescence. Now, the Arabidopsis mutants have paved our way and opened new vistas to elucidate the signalling mechanism of leaf senescence for which various mutants are being utilized. Recent studies demonstrating the role of microRNAs in leaf senescence have reinforced our knowledge of this intricate process. This review provides a comprehensive and critical analysis of the information gained particularly on the roles of several plant growth regulators and microRNAs in regulation of leaf senescence. PMID:23453916

  5. Interactions Between Temperature and Sugars in the Regulation of Leaf Senescence in the Perennial Herb Arabis alpina L.

    Institute of Scientific and Technical Information of China (English)

    Astrid Wingler; Emma Josefine Stangberg; Triambak Saxena; Rupal Mistry

    2012-01-01

    Annual plants usually flower and set seed once before senescence results in the death of the whole plant (monocarpic senescence).Leaf senescence also occurs in polycarpic perennials; even in "evergreen" species individual leaves senesce.In the annual model Arabidopsis thaliana sugars accumulate in the senescent leaves and senescence is accelerated by high sugar availability.Similar to A.thaliana,sugar contents increased with leaf age in the perennial Arabis alpina grown under warm conditions (22 ℃day/18 night).At 5 ℃,sugar contents in non-senescent leaves were higher than at a warm temperature,but dependent on the accession,either sugars did not accumulate or their contents decreased in old leaves.In A.alpina plants grown in their natural habitat in the Alps,sugar contents declined with leaf age.Growth at a cold temperature slightly delayed senescence in A.alpina.In both warm and cold conditions,an external glucose supply accelerated senescence,but natural variation was found in this response.In conclusion,sugar accumulation under warm conditions could accelerate leaf senescence in A.alpina plants,but genotype-specific responses and interactions with growth temperature are likely to influence senescence under natural conditions.

  6. Chloroplasts Are Central Players in Sugar-Induced Leaf Growth1[OPEN

    Science.gov (United States)

    De Milde, Liesbeth; Maleux, Katrien

    2016-01-01

    Leaves are the plant’s powerhouses, providing energy for all organs through sugar production during photosynthesis. However, sugars serve not only as a metabolic energy source for sink tissues but also as signaling molecules, affecting gene expression through conserved signaling pathways to regulate plant growth and development. Here, we describe an in vitro experimental assay, allowing one to alter the sucrose (Suc) availability during early Arabidopsis (Arabidopsis thaliana) leaf development, with the aim to identify the affected cellular and molecular processes. The transfer of seedlings to Suc-containing medium showed a profound effect on leaf growth by stimulating cell proliferation and postponing the transition to cell expansion. Furthermore, rapidly after transfer to Suc, mesophyll cells contained fewer and smaller plastids, which are irregular in shape and contain fewer starch granules compared with control mesophyll cells. Short-term transcriptional responses after transfer to Suc revealed the repression of well-known sugar-responsive genes and multiple genes encoded by the plastid, on the one hand, and up-regulation of a GLUCOSE-6-PHOSPHATE TRANSPORTER (GPT2), on the other hand. Mutant gpt2 seedlings showed no stimulation of cell proliferation and no repression of chloroplast-encoded transcripts when transferred to Suc, suggesting that GPT2 plays a critical role in the Suc-mediated effects on early leaf growth. Our findings, therefore, suggest that induction of GPT2 expression by Suc increases the import of glucose-6-phosphate into the plastids that would repress chloroplast-encoded transcripts, restricting chloroplast differentiation. Retrograde signaling from the plastids would then delay the transition to cell expansion and stimulate cell proliferation. PMID:26932234

  7. Analysis of Circadian Leaf Movements.

    Science.gov (United States)

    Müller, Niels A; Jiménez-Gómez, José M

    2016-01-01

    The circadian clock is a molecular timekeeper that controls a wide variety of biological processes. In plants, clock outputs range from the molecular level, with rhythmic gene expression and metabolite content, to physiological processes such as stomatal conductance or leaf movements. Any of these outputs can be used as markers to monitor the state of the circadian clock. In the model plant Arabidopsis thaliana, much of the current knowledge about the clock has been gained from time course experiments profiling expression of endogenous genes or reporter constructs regulated by the circadian clock. Since these methods require labor-intensive sample preparation or transformation, monitoring leaf movements is an interesting alternative, especially in non-model species and for natural variation studies. Technological improvements both in digital photography and image analysis allow cheap and easy monitoring of circadian leaf movements. In this chapter we present a protocol that uses an autonomous point and shoot camera and free software to monitor circadian leaf movements in tomato. PMID:26867616

  8. Arabidopsis ECERIFERUM9 involvement in cuticle formation and maintenance of plant water status

    Science.gov (United States)

    A unique set of allelic Arabidopsis mutants are described that exhibit either suppressed or completely inhibited expression of a gene designated ECERIFERUM9 (CER9). These mutants exhibit a dramatic elevation in the total amount of leaf cutin monomers, and a dramatic shift in the leaf cuticular wax p...

  9. Enhanced Expression and Activation of the Alternative Oxidase during Infection of Arabidopsis with Pseudomonas syringae pv tomato

    NARCIS (Netherlands)

    Simons, Bert H.; Millenaar, F.F.; Mulder, Lonneke; Loon, L.C. van; Lambers, Hans

    2002-01-01

    Cyanide-resistant ("alternative") respiration was studied in Arabidopsis during incompatible and compatible infection with Pseudomonas syringae pv tomato DC3000. Total leaf respiration increased as the leaves became necrotic, as did the cyanideresistant component that was sensitive to salicylhydroxa

  10. Cytokinin signaling regulates pavement cell morphogenesis in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Hongjiang Li; Tongda Xu; Deshu Lin; Mingzhang Wen; Mingtang Xie; Jér(o)me Duclercq; Agnieszka Bielach

    2013-01-01

    The puzzle piece-shaped Arabidopsis leaf pavement cells (PCs) with interdigitated lobes and indents is a good model system to investigate the mechanisms that coordinate cell polarity and shape formation within a tissue.Auxin has been shown to coordinate the interdigitation by activating ROP GTPase-dependent signaling pathways.To identify additional components or mechanisms,we screened for mutants with abnormal PC morphogenesis and found that cytokinin signaling regulates the PC interdigitation pattern.Reduction in cytokinin accumulation and defects in cytokinin signaling (such as in ARR7-over-expressing lines,the ahk3cre1 cytokinin receptor mutant,and the ahp12345 cytokinin signaling mutant) enhanced PC interdigitation,whereas over-production of cytokinin and over-activation of cytokinin signaling in an ARR20 over-expression line delayed or abolished PC interdigitation throughout the cotyledon.Genetic and biochemical analyses suggest that cytokinin signaling acts upstream of ROPs to suppress the formation of interdigitated pattern.Our results provide novel mechanistic understanding of the pathways controlling PC shape and uncover a new role for cytokinin signaling in cell morphogenesis.

  11. Elucidating the Role of Transport Processes in Leaf Glucosinolate Distribution

    DEFF Research Database (Denmark)

    Madsen, Svend Roesen; Olsen, Carl Erik; Nour-Eldin, Hussam Hassan;

    2014-01-01

    glucosinolates in Arabidopsis, also play key roles in glucosinolate allocation within a mature leaf by effectively importing apoplastically localized glucosinolates into appropriate cells. Detection of glucosinolates in root xylem sap unambiguously shows that this transport route is involved in root...... the margin accumulation is established through transport, little is known about these transport processes. Here, we show through leaf apoplastic fluid analysis and glucosinolate feeding experiments that two glucosinolate transporters, GTR1 and GTR2, essential for long-distance transport of......-to-shoot glucosinolate allocation. Detailed leaf dissections show that in the absence of GTR1 and GTR2 transport activity, glucosinolates accumulate predominantly in leaf margins and leaf tips. Furthermore, we show that glucosinolates accumulate in the leaf abaxial epidermis in a GTR-independent manner. Based on our...

  12. Altered life cycle in Arabidopsis plants expressing PsUGT1, a UDP-glucuronosyltransferase-encoding gene from pea.

    Science.gov (United States)

    Woo, Ho-Hyung; Faull, Kym F; Hirsch, Ann M; Hawes, Martha C

    2003-10-01

    Alfalfa (Medicago sativa) and Arabidopsis were used as model systems to examine molecular mechanisms underlying developmental effects of a microsomal UDP-glucuronosyltransferase-encoding gene from pea (Pisum sativum; PsUGT1). Alfalfa expressing PsUGT1 antisense mRNA under the control of the cauliflower mosaic virus (CaMV) 35S promoter exhibited delayed root emergence, reduced root growth, and increased lateral root development. The timing of root emergence in wild-type and antisense plants was correlated with the transient accumulation of auxin at the site of root emergence. Cell suspension cultures derived from the antisense alfalfa plants exhibited a delay in cell cycle from 24-h in the wild-type plants to 48-h in the antisense plants. PsUGT1::uidA was introduced into Arabidopsis to demonstrate that, as in alfalfa and pea, PsUGT1 expression occurs in regions of active cell division. This includes the root cap and root apical meristems, leaf primordia, tips of older leaves, and the transition zone between the hypocotyl and the root. Expression of PsUGT1::uidA colocalized with the expression of the auxin-responding reporter DR5::uidA. Co-expression of DR5::uidA in transgenic Arabidopsis lines expressing CaMV35S::PsUGT1 revealed that ectopic expression of CaMV35S::PsUGT1 is correlated with a change in endogenous auxin gradients in roots. Roots of ecotype Columbia expressing CaMV35S::PsUGT1 exhibited distinctive responses to exogenous naphthalene acetic acid. Completion of the life cycle occurred in 4 to 6 weeks compared with 6 to 7 weeks for wild-type Columbia. Inhibition of endogenous ethylene did not correct this early senescence phenotype. PMID:12972656

  13. Delayed fission

    International Nuclear Information System (INIS)

    Delayed fission is a nuclear process that couples beta decay and fission. In the delayed fission process, a parent nucleus undergoes beta decay or electron capture and thus populates excited states in the daughter nucleus. This review covers experimental methods for detecting and measuring delayed fission. Experimental results (ECDF activities and beta-DF activities) and theory are presented. The future prospects for study of delayed fission are discussed. 50 refs., 8 figs., 2 tabs

  14. C2-substituted aromatic cytokinin sugar conjugates delay the onset of senescence by maintaining the activity of the photosynthetic apparatus.

    Science.gov (United States)

    Vylíčilová, Hana; Husičková, Alexandra; Spíchal, Lukáš; Srovnal, Josef; Doležal, Karel; Plíhal, Ondřej; Plíhalová, Lucie

    2016-02-01

    Cytokinins are plant hormones with biological functions ranging from coordination of plant growth and development to the regulation of senescence. A series of 2-chloro-N(6)-(halogenobenzylamino)purine ribosides was prepared and tested for cytokinin activity in detached wheat leaf senescence, tobacco callus and Amaranthus bioassays. The synthetic compounds showed significant activity, especially in delaying senescence in detached wheat leaves. They were also tested in bacterial receptor bioassays using both monocot and dicot members of the cytokinin receptor family. Most of the derivatives did not trigger cytokinin signaling via the AHK3 and AHK4 receptors from Arabidopsis thaliana in the bacterial assay, but some of them specifically activated the ZmHK1 receptor from Zea mays and were also more active than the aromatic cytokinin BAP in an ARR5::GUS cytokinin bioassay using transgenic Arabidopsis plants. Whole transcript expression analysis was performed using an Arabidopsis model to gather information about the reprogramming of gene transcription when senescent leaves were treated with selected C2-substituted aromatic cytokinin ribosides. Genome-wide expression profiling revealed that the synthetic halogenated derivatives induced the expression of genes related to cytokinin signaling and metabolism. They also prompted both up- and down-regulation of a unique combination of genes coding for components of the photosystem II (PSII) reaction center, light-harvesting complex II (LHCII), and the oxygen-evolving complex, as well as several stress factors responsible for regulating photosynthesis and chlorophyll degradation. Chlorophyll content and fluorescence analyses demonstrated that treatment with the halogenated derivatives increased the efficiency of PSII photochemistry and the abundance of LHCII relative to DMSO- and BAP-treated controls. These findings demonstrate that it is possible to manipulate and fine-tune leaf longevity using synthetic aromatic cytokinin

  15. Influence of IAA Treatment on Isolation of Protoplasts in Leaf of Arabidopsis thaliana%IAA处理对拟南芥叶原生质体分离的影响

    Institute of Scientific and Technical Information of China (English)

    赵严伟; 黄志刚; 李合松

    2011-01-01

    By treated leaves of Arabidopsis thaliana with different concentrations of IAA, the changes of amount and activity of protoplasts under different enzymolysis methods with different enzymatic solution combinations and different enzymolysis time were compared to analyze influence of IAA on isolation of protoplast. The results showed that 10-7 mol/L of IAA can effectively improve amount and activity of protoplasts, and the activity of protoplast was the highest when combining 0.6% cellulase R-10 with 0.2% macerozyme R-10, which was 87.44%. IAA also can enhance isolation speed of protoplasts.%通过对拟南芥叶片进行不同浓度的IAA处理,比较其在不同的酶解方式、酶液组合、酶解时间下原生质体数量与活力的变化,探讨了IAA对原生质体分离的影响.结果表明,10-7 mol/L的IAA能有效增加活力原生质体数量,且在与0.6%纤维素酶R-10与0.2%离析酶R-10组合时活力最高,为87.44%.材料外施IAA可提高原生质体分离速率.

  16. Two alanine aminotranferases link mitochondrial glycolate oxidation to the major photorespiratory pathway in Arabidopsis and rice

    OpenAIRE

    Niessen, M; K. Krause; Horst, I.; Staebler, N.; Klaus, S; Gaertner, S.; Kebeish, R.; Araujo, W.; Fernie, A.; Peterhansel, C.

    2012-01-01

    The major photorespiratory pathway in higher plants is distributed over chloroplasts, mitochondria, and peroxisomes. In this pathway, glycolate oxidation takes place in peroxisomes. It was previously suggested that a mitochondrial glycolate dehydrogenase (GlcDH) that was conserved from green algae lacking leaf-type peroxisomes contributes to photorespiration in Arabidopsis thaliana. Here, the identification of two Arabidopsis mitochondrial alanine:glyoxylate aminotransferases (ALAATs) that li...

  17. ML3: a novel regulator of herbivory-induced responses in Arabidopsis thaliana

    OpenAIRE

    Fridborg, I.; Johansson, A; Lagensjo, J.; Leelarasamee, N.; Floková, K. (Kristýna); Tarkowská, D. (Danuše); Meijer, J.; Bejai, S.

    2013-01-01

    ML (MD2-related lipid recognition) proteins are known to enhance innate immune responses in mammals. This study reports the analysis of the putative ML gene family in Arabidopsis thaliana and suggests a role for the ML3 gene in herbivory-associated responses in plants. Feeding by larvae of the Lepidopteran generalist herbivore Spodoptera littoralis and larvae of the specialist herbivore Plutella xylostella activated ML3 transcription in leaf tissues. ML3 loss-of-function Arabidopsis plants we...

  18. Leaf Senescence Induced by Mild Water Deficit Follows the Same Sequence of Macroscopic, Biochemical, and Molecular Events as Monocarpic Senescence in Pea1

    Science.gov (United States)

    Pic, Emmanuelle; de la Serve, Bernard Teyssendier; Tardieu, François; Turc, Olivier

    2002-01-01

    We have compared the time course of leaf senescence in pea (Pisum sativum L. cv Messire) plants subjected to a mild water deficit to that of monocarpic senescence in leaves of three different ages in well-watered plants and to that of plants in which leaf senescence was delayed by flower excision. The mild water deficit (with photosynthesis rate maintained at appreciable levels) sped up senescence by 15 d (200°Cd), whereas flower excision delayed it by 17 d (270°Cd) compared with leaves of the same age in well-watered plants. The range of life spans in leaves of different ages in control plants was 25 d (340°Cd). In all cases, the first detected event was an increase in the mRNA encoding a cysteine-proteinase homologous to Arabidopsis SAG2. This happened while the photosynthesis rate and the chlorophyll and protein contents were still high. The 2-fold variability in life span of the studied leaves was closely linked to the duration from leaf unfolding to the beginning of accumulation of this mRNA. In contrast, the duration of the subsequent phases was essentially conserved in all studied cases, except in plants with excised flowers, where the degradation processes were slower. These results suggest that senescence in water-deficient plants was triggered by an early signal occurring while leaf photosynthesis was still active, followed by a program similar to that of monocarpic senescence. They also suggest that reproductive development plays a crucial role in the triggering of senescence. PMID:11788769

  19. Dataset of Arabidopsis plants that overexpress FT driven by a meristem-specific KNAT1 promoter

    OpenAIRE

    Duplat-Bermúdez, L.; Ruiz-Medrano, R.; Landsman, D.; Mariño-Ramírez, L; Xoconostle-Cázares, B.

    2016-01-01

    In this dataset we integrated figures comparing leaf number and rosette diameter in three Arabidopsis FT overexpressor lines (AtFTOE) driven by KNAT1 promoter, “A member of the KNOTTED class of homeodomain proteins encoded by the STM gene of Arabidopsis” [5], vs Wild Type (WT) Arabidopsis plats. Also, presented in the tables are some transcriptomic data obtained by RNA-seq Illumina HiSeq from rosette leaves of Arabidopsis plants of AtFTOE 2.1 line vs WT with accession numbers SRR2094583 and S...

  20. Crescimento, desenvolvimento e retardamento da senescência foliar em girassol de vaso (Helianthus annuus L.: fontes e doses de nitrogênio Growth, development and delay of leaf senescence in pot-grown sunflower (Helianthus annuus L.: sources and rates of nitrogen

    Directory of Open Access Journals (Sweden)

    Joelma Dutra Fagundes

    2007-08-01

    Full Text Available O girassol é a quarta oleaginosa em produção de grãos no mundo e alguns genótipos são usados com finalidade ornamental para flor de corte e de vaso (girassol de vaso. O objetivo do trabalho foi avaliar o efeito de diferentes fontes e doses de nitrogênio sobre alguns parâmetros de crescimento, desenvolvimento e no retardamento da senescência das folhas basais em girassol de vaso. Um experimento foi conduzido em casa de vegetação, em Santa Maria, RS. Os tratamentos foram: uréia, nitrato de amônio e nitrato de cálcio nas doses de 0, 50, 100 e 150mg L-1 de N na solução de fertirrigação, com duas aplicações semanais. O experimento foi um bi-fatorial (fontes e doses de N no delineamento inteiramente casualizado, com seis repetições. Cada repetição foi um vaso no 15 (1,3L, 15cm de altura com uma planta por vaso. As variáveis analisadas foram: número final de folhas, altura final de plantas, porcentagem de folhas senescentes no ponto de venda, porcentagem de folhas senescentes no final de vida de vaso, área foliar total da planta, filocrono e a soma térmica acumulada da emergência ao botão visível e da emergência ao ponto de venda. A fonte de N tem influência sobre a área foliar do girassol de vaso, sendo a uréia recomendável para o maior crescimento das folhas. A dose de N em torno de 100mg L-1 aplicada duas vezes por semana via fertirrigação favorece características desejáveis para a comercialização, como precocidade e retardamento da senescência das folhas.Sunflower is the fourth oil grain crop grown worldwide and some genotypes are used with ornamental purpose as cut and pot-grown flower. The objective of this study was to evaluate the effect of different sources and rates of nitrogen on some growth and developmental parameters, and on the delay of leaf senescence in pot-grown sunflower. An experiment was carried out inside a greenhouse in Santa Maria, RS, Brazil. Treatments were: urea, ammonium nitrate and

  1. The NAC transcription factor ANAC046 is a positive regulator of chlorophyll degradation and senescence in Arabidopsis leaves

    Science.gov (United States)

    Oda-Yamamizo, Chihiro; Mitsuda, Nobutaka; Sakamoto, Shingo; Ogawa, Daisuke; Ohme-Takagi, Masaru; Ohmiya, Akemi

    2016-01-01

    Chlorophyll (Chl) degradation occurs during leaf senescence, embryo degreening, bud breaking, and fruit ripening. The Chl catabolic pathway has been intensively studied and nearly all the enzymes involved are identified and characterized; however, the molecular regulatory mechanisms of this pathway are largely unknown. In this study, we performed yeast one-hybrid screening using a transcription factor cDNA library to search for factors controlling the expression of Chl catabolic genes. We identified ANAC046 as a common regulator that directly binds to the promoter regions of NON-YELLOW COLORING1, STAY-GREEN1 (SGR1), SGR2, and PHEOPHORBIDE a OXYGENASE. Transgenic plants overexpressing ANAC046 exhibited an early-senescence phenotype and a lower Chl content in comparison with the wild-type plants, whereas loss-of-function mutants exhibited a delayed-senescence phenotype and a higher Chl content. Microarray analysis of ANAC046 transgenic plants showed that not only Chl catabolic genes but also senescence-associated genes were positively regulated by ANAC046. We conclude that ANAC046 is a positive regulator of Arabidopsis leaf senescence and exerts its effect by controlling the expression of Chl catabolic genes and senescence-associated genes. PMID:27021284

  2. Delayed discharge.

    Science.gov (United States)

    Allen, Daniel

    2016-07-01

    Essential facts Delays in discharging older peo ple from hospital cost the NHS £820 million a year, according to a report from the National Audit Office (NAO). Last year in acute hospitals, 1.15 million bed days were lost to delayed transfers of care, an increase of 31% since 2013. The NAO says rising demand for NHS services is compounded by reduced local authority spending on adult social care - down by 10% since 2009-10. PMID:27380673

  3. Collection of apoplastic fluids from Arabidopsis thaliana leaves

    DEFF Research Database (Denmark)

    Madsen, Svend Roesen; Nour-Eldin, Hussam Hassan; Halkier, Barbara Ann

    2016-01-01

    The leaf apoplast comprises the extracellular continuum outside cell membranes. A broad range of processes take place in the apoplast, including intercellular signaling, metabolite transport, and plant-microbe interactions. To study these processes, it is essential to analyze the metabolite content...... in apoplastic fluids. Due to the fragile nature of leaf tissues, it is a challenge to obtain apoplastic fluids from leaves. Here, methods to collect apoplastic washing fluid and guttation fluid from Arabidopsis thaliana leaves are described....

  4. 磷脂酶Dδ对拟南芥叶片衰老过程中内源ROS和激素含量的影响%The Effects of Phospholipase Dδ Suppression on the Responses of ROS and Hormones to Artificial Leaf Senescence in Arabidopsis thanliana

    Institute of Scientific and Technical Information of China (English)

    贾艳霞; 陶发清; 李唯奇

    2013-01-01

    活性氧(ROS)和植物激素是植物衰老过程中重要的内在或者外在的调控因子.我们发现,相对于离体诱导的衰老过程,在脱落酸(ABA)和乙烯(ethylene)促进的衰老过程中有较多的活性氧积累;在对拟南芥磷脂酶Dδ (PLDδ)缺失型突变体的研究中发现,与野生型相比,突变体在衰老过程中产生较少的活性氧.我们比较了上述两种基因型的离体叶片在离体、ABA和ethylene三种衰老处理下内源的ABA、茉莉酸甲酯(MeJA)、玉米素核苷(Zeatin Riboside,ZR)和吲哚乙酸(IAA)的含量变化,发现每一种激素对上述三种衰老处理的响应模式都很相似.在离体诱导的衰老中,两种基因型拟南芥的内源激素含量没有差异;而在ABA促进的衰老过程中,PLDδ缺失型突变体叶片中的MeJA的含量较低,ZR和IAA含量较高;在乙烯促进的衰老过程中,突变体中的ABA和MeJA的含量较低,ZR和IAA含量较高.上述内源激素的这种变化可能有助于延缓突变体的衰老.%The reactive oxygen species (ROS) and hormones can act as an important internal or external factor influencing plant senescence.In the present study,we found that suppression of phospholipase Dδ (PLDδ) attenuated ROS production during abscisic acid (ABA)-and ethylene-promoted leaf senescence.We also comparatively analyzed the content of endogenous hormones,ABA,methyl jasmonate (MeJA),indole-3-acetic acid (IAA),and total zeatin in detachment induced-senescence leaves,exogenous ABA and ethylene-promoted senescence in wild type and PLDδ-knockout (PLDδ-KO) Arabidopsis leaves.We found that the response patterns of the four endogenous hormones to the three senescence treatments were identical.In comparison with wild type,PLDδ-KO plants showed higher ZR and IAA levels and lower MeJA content under ABA and higher ZR and IAA levels and lower ABA and MeJA content under ethylene.The results suggested that these hormones might contribute to retarding ABA

  5. Senescence-specific Alteration of Hydrogen Peroxide Levels in Arabidopsis thaliana and Oilseed Rape Spring Variety Brassica napus L.cv.Mozart

    Institute of Scientific and Technical Information of China (English)

    Stefan Bieker; Lena Riester; Mark Stahl; Jürgen Franzaring; Ulrike Zentgraf

    2012-01-01

    In order to analyze the signaling function of hydrogen peroxide (H2O2) production in senescence in more detail,we manipulated intracellular H2O2 levels in Arabidopsis thaliala (L.) Heynh by using the hydrogenperoxide-sensitive part of the Escherichia coli transcription regulator OxyR,which was directed to the cytoplasm as well as into the peroxisomes.H2O2 levels were lowered and senescence was delayed in both transgenic lines,but OxyR was found to be more effective in the cytoplasm.To transfer this knowledge to crop plants,we analyzed oilseed rape plants Brassica napus L.cv.Mozart for H2O2 and its scavenging enzymes catalase (CAT) and ascorbate peroxidase (APX) during leaf and plant development.H2O2 levels were found to increase during bolting and flowering time,but no increase could be observed in the very late stages of senescence.With increasing H2O2 levels,CAT and APX activities declined,so it is likely that similar mechanisms are used in oilseed rape and Arabidopsis to control H2O2 levels.Under elevated CO2 conditions,oilseed rape senescence was accelerated and coincided with an earlier increase in H2O2 levels,indicating that H2O2 may be one of the signals to inducing senescence in a broader range of Brassicaceae.

  6. Phosphoprotein Enrichment Combined with Phosphopeptide Enrichment to Identify Putative Phosphoproteins During Defense Response in Arabidopsis thaliana.

    Science.gov (United States)

    Lassowskat, Ines; Hoehenwarter, Wolfgang; Lee, Justin; Scheel, Dierk

    2016-01-01

    Phosphoprotein/peptide enrichment is an important technique to elucidate signaling components of defense responses with mass spectrometry. Normally, proteins can be detected easily by shotgun experiments but the low abundance of phosphoproteins hinders their detection. Here, we describe a combination of prefractionation with desalting, phosphoprotein and phosphopeptide enrichment to effectively accumulate phosphorylated proteins from leaf tissue of stressed Arabidopsis plants. PMID:26867639

  7. Genetic, molecular, and morphological analysis of compound leaf development.

    Science.gov (United States)

    Goliber, T; Kessler, S; Chen, J J; Bharathan, G; Sinha, N

    1999-01-01

    Leaves, the plant organs responsible for capturing and converting most of the 170 billion metric tons of carbon fixed globally each year, can be broadly grouped into two morphological categories: simple and compound. Although simple-leaved species such as corn and Arabidopsis have traditionally been favored model systems for studying leaf development, recent years have seen an increase in genetic and molecular studies of compound leaf development. Two compound-leaved species in particular have emerged as model systems: tomato and pea. A variety of mutations which alter leaf morphology in these species have been described, and analyses of these mutations have allowed the construction of testable models of leaf development. Also, the knotted-like homeobox (KNOX) genes, which were originally discovered as regulators of meristem function, now appear to have a role in compound leaf development. In addition to the recent genetic and molecular analyses of tomato and pea, insight into the nature of compound leaf development may be gained through the study of (a) heteroblasty and heterophylly, phenomena in which a range of leaf forms can be produced by a single shoot, and (b) the evolutionary origins of compound leaves. PMID:9891889

  8. Delayed privatization

    OpenAIRE

    Bernardo Bortolotti; Paolo Pinotti

    2008-01-01

    This paper studies the timing of privatization in 21 major developed economies in the 1977-2002 period. Duration analysis shows that political fragmentation plays a significant role in explaining government's decision to privatize: privatization is delayed longer in democracies characterized by a larger number of parties and operating under proportional electoral rules, as predicted by war of attrition models of economic reform. Results are robust to various assumptions on the underlying stat...

  9. Phytotoxicity of trichothecenes using an Arabidopsis detached leaf assay

    Science.gov (United States)

    Trichothecenes are sesquiterpenoid epoxide mycotoxins produced by Fusarium and other fungi. Although some Fusarium trichothecenes are virulence factors in plant disease, the phytotoxicities of many trichothecenes have not been investigated. Results of previous studies, using a limited group of tri...

  10. Phytotoxicity of trichothecenes using Arabidopsis detached leaf and Chlamydomonas assays

    Science.gov (United States)

    Many plant pathogenic species of the genus Fusarium produce trichothecenes, a large group of sesquiterpene epoxides that are inhibitors of eukaryotic protein synthesis. Fusarium graminearum, F. sporotrichioides, and other trichothecene-producing Fusarium species are common pathogens of cereal grain...

  11. Regeneration from leaf protoplasts of Arabidopsis thaliana ecotype estland.

    Science.gov (United States)

    Gandhi, R; Khurana, P

    2001-07-01

    Protoplasts (2 x 10(7)/g fresh wt) were isolated from leaves of A. thaliana ecotype estland, with a viability of more than 90%. Protoplasts cultured in calcium alginate beads or layers showed division while culture in liquid or agarose beads failed to elicit any division. Effect of culture density showed highest frequency of division occurring at 5 x 10(5) while no division was seen when cultured at a density of 5 x 10(4). Culture in MS medium resulted in higher division frequency and better sustenance of microcolonies as compared to B5 medium. Under optimized conditions, macrocolonies were formed at a frequency of 1.8%. Shoot regeneration was seen in 50% of microcalli transferred to shoot induction medium for regeneration. Shoots were rooted and plantlets transferred to pots. The plants produced flowers and were fertile. PMID:12019766

  12. Leaf senescence in alstroemeria: regulation by phytochrome gibberellins and cytokinins.

    OpenAIRE

    Kappers, I

    1998-01-01

    Leaf senescence in plants is a regulated process influenced by light as well as phytohormones. In the present study the putative role of the phytohormones cytokinins and gibberellins as mediators for the light signal on leaf senescence in alstroemeria was studied. It was found that low photon fluences of red light ensured maximal delay of chlorophyll and protein breakdown. This effect of red light could be completely counteracted by a subsequent far red irradiation, indicating phytochrome inv...

  13. Mapping leaf surface landscapes.

    OpenAIRE

    Mechaber, W.L.; Marshall, D B; Mechaber, R A; Jobe, R T; Chew, F S

    1996-01-01

    Leaf surfaces provide the ecologically relevant landscapes to those organisms that encounter or colonize the leaf surface. Leaf surface topography directly affects microhabitat availability for colonizing microbes, microhabitat quality and acceptability for insects, and the efficacy of agricultural spray applications. Prior detailed mechanistic studies that examined particular fungi-plant and pollinator-plant interactions have demonstrated the importance of plant surface topography or roughne...

  14. Arabidopsis Growth Simulation Using Image Processing Technology

    Directory of Open Access Journals (Sweden)

    Junmei Zhang

    2014-01-01

    Full Text Available This paper aims to provide a method to represent the virtual Arabidopsis plant at each growth stage. It includes simulating the shape and providing growth parameters. The shape is described with elliptic Fourier descriptors. First, the plant is segmented from the background with the chromatic coordinates. With the segmentation result, the outer boundary series are obtained by using boundary tracking algorithm. The elliptic Fourier analysis is then carried out to extract the coefficients of the contour. The coefficients require less storage than the original contour points and can be used to simulate the shape of the plant. The growth parameters include total area and the number of leaves of the plant. The total area is obtained with the number of the plant pixels and the image calibration result. The number of leaves is derived by detecting the apex of each leaf. It is achieved by using wavelet transform to identify the local maximum of the distance signal between the contour points and the region centroid. Experiment result shows that this method can record the growth stage of Arabidopsis plant with fewer data and provide a visual platform for plant growth research.

  15. A multiple-method approach reveals a declining amount of chloroplast DNA during development in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Oldenburg Delene J

    2009-01-01

    Full Text Available Abstract Background A decline in chloroplast DNA (cpDNA during leaf maturity has been reported previously for eight plant species, including Arabidopsis thaliana. Recent studies, however, concluded that the amount of cpDNA during leaf development in Arabidopsis remained constant. Results To evaluate alternative hypotheses for these two contradictory observations, we examined cpDNA in Arabidopsis shoot tissues at different times during development using several methods: staining leaf sections as well as individual isolated chloroplasts with 4',6-diamidino-2-phenylindole (DAPI, real-time quantitative PCR with DNA prepared from total tissue as well as from isolated chloroplasts, fluorescence microscopy of ethidium-stained DNA molecules prepared in gel from isolated plastids, and blot-hybridization of restriction-digested total tissue DNA. We observed a developmental decline of about two- to three-fold in mean DNA per chloroplast and two- to five-fold in the fraction of cellular DNA represented by chloroplast DNA. Conclusion Since the two- to five-fold reduction in cpDNA content could not be attributed to an artifact of chloroplast isolation, we conclude that DNA within Arabidopsis chloroplasts is degraded in vivo as leaves mature.

  16. Metabolic footprint of epiphytic bacteria on Arabidopsis thaliana leaves.

    Science.gov (United States)

    Ryffel, Florian; Helfrich, Eric Jn; Kiefer, Patrick; Peyriga, Lindsay; Portais, Jean-Charles; Piel, Jörn; Vorholt, Julia A

    2016-03-01

    The phyllosphere, which is defined as the parts of terrestrial plants above the ground, is a large habitat for different microorganisms that show a high extent of adaption to their environment. A number of hypotheses were generated by culture-independent functional genomics studies to explain the competitiveness of specialized bacteria in the phyllosphere. In contrast, in situ data at the metabolome level as a function of bacterial colonization are lacking. Here, we aimed to obtain new insights into the metabolic interplay between host and epiphytes upon colonization of Arabidopsis thaliana leaves in a controlled laboratory setting using environmental metabolomics approaches. Quantitative nuclear magnetic resonance (NMR) and imaging high-resolution mass spectrometry (IMS) methods were used to identify Arabidopsis leaf surface compounds and their possible involvement in the epiphytic lifestyle by relative changes in compound pools. The dominant carbohydrates on the leaf surfaces were sucrose, fructose and glucose. These sugars were significantly and specifically altered after epiphytic leaf colonization by the organoheterotroph Sphingomonas melonis or the phytopathogen Pseudomonas syringae pv. tomato, but only to a minor extent by the methylotroph Methylobacterium extorquens. In addition to carbohydrates, IMS revealed surprising alterations in arginine metabolism and phytoalexin biosynthesis that were dependent on the presence of bacteria, which might reflect the consequences of bacterial activity and the recognition of not only pathogens but also commensals by the plant. These results highlight the power of environmental metabolomics to aid in elucidating the molecular basis underlying plant-epiphyte interactions in situ. PMID:26305156

  17. Comparison of freezing tolerance, compatible solutes and polyamines in geographically diverse collections of Thellungiella sp. and Arabidopsis thaliana accessions

    Directory of Open Access Journals (Sweden)

    Lee Yang

    2012-08-01

    Full Text Available Abstract Background Thellungiella has been proposed as an extremophile alternative to Arabidopsis to investigate environmental stress tolerance. However, Arabidopsis accessions show large natural variation in their freezing tolerance and here the tolerance ranges of collections of accessions in the two species were compared. Results Leaf freezing tolerance of 16 Thellungiella accessions was assessed with an electrolyte leakage assay before and after 14 days of cold acclimation at 4°C. Soluble sugars (glucose, fructose, sucrose, raffinose and free polyamines (putrescine, spermidine, spermine were quantified by HPLC, proline photometrically. The ranges in nonacclimated freezing tolerance completely overlapped between Arabidopsis and Thellungiella. After cold acclimation, some Thellungiella accessions were more freezing tolerant than any Arabidopsis accessions. Acclimated freezing tolerance was correlated with sucrose levels in both species, but raffinose accumulation was lower in Thellungiella and only correlated with freezing tolerance in Arabidopsis. The reverse was true for leaf proline contents. Polyamine levels were generally similar between the species. Only spermine content was higher in nonacclimated Thellungiella plants, but decreased during acclimation and was negatively correlated with freezing tolerance. Conclusion Thellungiella is not an extremophile with regard to freezing tolerance, but some accessions significantly expand the range present in Arabidopsis. The metabolite data indicate different metabolic adaptation strategies between the species.

  18. Arabidopsis in Wageningen

    OpenAIRE

    Koornneef, M

    2013-01-01

    Arabidopsis thaliana is the plant species that in the past 25 years has developed into the major model species in plant biology research. This was due to its properties such as short generation time, its small genome and its easiness to be transformed. Wageningen University has played an important role in the development of this model, based on interdisciplinary collaborations using genetics as a major tool to investigate aspects of physiology, development, plant-microbe interactions and evol...

  19. ORS1,an H2O2-Responsive NAC Transcription Factor,Controls Senescence in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Salma Balazadeh; Miroslaw Kwasniewski; Camila Caldana; Mohammad Mehrnia; María Inés Zanor; Gang-Ping Xue; Bernd Mueller-Roeber

    2011-01-01

    We report here that ORS1,a previously uncharacterized member of the NAC transcription factor family,controls leaf senescence in Arabidopsis thaliana. Overexpression of ORS1 accelerates senescence in transgenic plants,whereas its inhibition delays it. Genes acting downstream of ORS1 were identified by global expression analysis using transgenic plants producing dexamethasone-inducible ORS1-GR fusion protein. Of the 42 up-regulated genes,30 (~70%) were previously shown to be up-regulated during age-dependent senescence. We also observed that 32 (~76%) of the ORS1-de-pendent genes were induced by long-term (4 d),but not short-term (6 h) salinity stress (150 mM NaCI). Furthermore,expression of 16 and 24 genes,respectively,was induced after 1 and 5 h of treatment with hydrogen peroxide (H2O2),a reactive oxygen species known to accumulate during salinity stress. ORS1 itself was found to be rapidly and strongly induced by H2O2 treatment in both leaves and roots. Using in vitro binding site selection,we determined the preferred binding motif of ORS1 and found it to be present in half of the ORS1 -dependent genes. ORS1 is a paralog of ORE1/ ANAC092/AtNAC2,a previously reported regulator of leaf senescence. Phylogenetic footprinting revealed evolutionary conservation of the ORS1 and ORE1 promoter sequences in different Brassicaceae species,indicating strong positive selection acting on both genes. We conclude that ORS1,similarly to ORE1,triggers expression of senescence-associated genes through a regulatory network that may involve cross-talk with salt- and H2O2-dependent signaling pathways.

  20. Leaf spring, and electromagnetic actuator provided with a leaf spring

    OpenAIRE

    Berkhoff, Arthur Perry; Lemmen, Remco Louis Christiaan

    2002-01-01

    The invention relates to a leaf spring for an electromagnetic actuator and to such an electromagnetic actuator. The leaf spring is formed as a whole from a disc of plate-shaped, resilient material. The leaf spring comprises a central fastening part, an outer fastening part extending therearound and at least two leaf spring arms extending between the central and outer fastening part. Viewed from the central fastening part, the leaf spring arms (23) have a first zone (24) originating from the c...

  1. 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

  2. STENOFOLIA acts as a repressor in regulating leaf blade outgrowth

    OpenAIRE

    Lin, Hao; Niu, Lifang; Tadege, Million

    2013-01-01

    We recently reported that the Medicago WOX gene, STENOFOLIA (STF), acts as a transcriptional repressor in regulating leaf blade outgrowth. By using the Nicotiana sylvestris bladeless lam1 mutant as a genetic tool, we showed that the WUS-box, which is conserved among WUS clade WOX genes, is partly responsible for the repressive activity of STF. All members of the modern/WUS clade genes (WUS, WOX1-WOX7) in Arabidopsis that contain intact WUS-box can substitute for STF/LAM1 function while the in...

  3. Geometric leaf placement strategies

    International Nuclear Information System (INIS)

    Geometric leaf placement strategies for multileaf collimators (MLCs) typically involve the expansion of the beam's-eye-view contour of a target by a uniform MLC margin, followed by movement of the leaves until some point on each leaf end touches the expanded contour. Film-based dose-distribution measurements have been made to determine appropriate MLC margins-characterized through an index d90-for multileaves set using one particular strategy to straight lines lying at various angles to the direction of leaf travel. Simple trigonometric relationships exist between different geometric leaf placement strategies and are used to generalize the results of the film work into d90 values for several different strategies. Measured d90 values vary both with angle and leaf placement strategy. A model has been derived that explains and describes quite well the observed variations of d90 with angle. The d90 angular variations of the strategies studied differ substantially, and geometric and dosimetric reasoning suggests that the best strategy is the one with the least angular variation. Using this criterion, the best straightforwardly implementable strategy studied is a 'touch circle' approach for which semicircles are imagined to be inscribed within leaf ends, the leaves being moved until the semicircles just touch the expanded target outline

  4. The Significance of Hydrogen Sulfide for Arabidopsis Seed Germination

    Science.gov (United States)

    Baudouin, Emmanuel; Poilevey, Aurélie; Hewage, Nishodi Indiketi; Cochet, Françoise; Puyaubert, Juliette; Bailly, Christophe

    2016-01-01

    Hydrogen sulfide (H2S) recently emerged as an important gaseous signaling molecule in plants. In this study, we investigated the possible functions of H2S in regulating Arabidopsis seed germination. NaHS treatments delayed seed germination in a dose-dependent manner and were ineffective in releasing seed dormancy. Interestingly, endogenous H2S content was enhanced in germinating seeds. This increase was correlated with higher activity of three enzymes (L-cysteine desulfhydrase, D-cysteine desulfhydrase, and β-cyanoalanine synthase) known as sources of H2S in plants. The H2S scavenger hypotaurine and the D/L cysteine desulfhydrase inhibitor propargylglycine significantly delayed seed germination. We analyzed the germinative capacity of des1 seeds mutated in Arabidopsis cytosolic L-cysteine desulfhydrase. Although the mutant seeds do not exhibit germination-evoked H2S formation, they retained similar germination capacity as the wild-type seeds. In addition, des1 seeds responded similarly to temperature and were as sensitive to ABA as wild type seeds. Taken together, these data suggest that, although its metabolism is stimulated upon seed imbibition, H2S plays, if any, a marginal role in regulating Arabidopsis seed germination under standard conditions.

  5. An early nodulin-like protein accumulates in the sieve element plasma membrane of Arabidopsis

    DEFF Research Database (Denmark)

    Khan, Junaid A.; Wang, Qi; Sjölund, Richard D.;

    2007-01-01

    ) tissue cultures, recognizes an antigen in the Arabidopsis (Arabidopsis thaliana) ecotype Columbia that is associated specifically with the plasma membrane of sieve elements, but not companion cells, and accumulates at the earliest stages of sieve element differentiation. The identity of the RS6 antigen...... cleaved from the precursor protein, resulting in a mature peptide of approximately 15 kD that is attached to the sieve element plasma membrane via a carboxy-terminal glycosylphosphatidylinositol membrane anchor. Many of the Arabidopsis ENOD-like proteins accumulate in gametophytic tissues, whereas in both......Membrane proteins within the sieve element-companion cell complex have essential roles in the physiological functioning of the phloem. The monoclonal antibody line RS6, selected from hybridomas raised against sieve elements isolated from California shield leaf (Streptanthus tortuosus; Brassicaceae...

  6. Auxin distribution and transport during embryogenesis and seed germi-nation of Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Auxin distribution during embryogenesis and seed germination were studied with transgenic Arabidopsis plants expressing GUS gene driven by a synthetic DR5 promoter, an auxin responsive promoter. The results showed that GUS activity is higher in ends of hypophysis and cotyledon primordia of heart-, torpedo- and cotyledon-stage embryos, leaf tip area, lateral root primordia, root apex and cotyledon of young seedlings.And GUS accumulated in root apex of the seedlings grown on auxin transport inhibitor containing media.All these suggested that above-mentioned part of the organs and tissues have a higher level of auxin, and auxin polar transport inhibitor could cause the accumulation of auxin in root apex. And auxin transport inhibitor also resulted in aberration of Arabidopsis leaf pattern formation, root gravitropism and elongation.

  7. Deer predation on leaf miners via leaf abscission

    Science.gov (United States)

    Yamazaki, Kazuo; Sugiura, Shinji

    2008-03-01

    The evergreen oak Quercus gilva Blume sheds leaves containing mines of the leaf miner Stigmella sp. (Lepidoptera: Nepticulidae) earlier than leaves with no mines in early spring in Nara, central Japan. The eclosion rates of the leaf miner in abscised and retained leaves were compared in the laboratory to clarify the effects of leaf abscission on leaf miner survival in the absence of deer. The leaf miner eclosed successfully from both fallen leaves and leaves retained on trees. However, sika deer ( Cervus nippon centralis Kishida) feed on the fallen mined leaves. Field observations showed that deer consume many fallen leaves under Q. gilva trees, suggesting considerable mortality of leaf miners due to deer predation via leaf abscission. This is a previously unreported relationship between a leaf miner and a mammalian herbivore via leaf abscission.

  8. An Arabidopsis callose synthase

    DEFF Research Database (Denmark)

    Ostergaard, Lars; Petersen, Morten; Mattsson, Ole;

    2002-01-01

    unclear whether callose synthases can also produce cellulose and whether plant cellulose synthases may also produce beta-1,3-glucans. We describe here an Arabidopsis gene, AtGsl5, encoding a plasma membrane-localized protein homologous to yeast beta-1,3-glucan synthase whose expression partially......Beta-1,3-glucan polymers are major structural components of fungal cell walls, while cellulosic beta-1,4-glucan is the predominant polysaccharide in plant cell walls. Plant beta-1,3-glucan, called callose, is produced in pollen and in response to pathogen attack and wounding, but it has been...

  9. Genome-wide Analysis of Ovate Family Proteins in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Huang Jian-ping; Li Hong-ling; Chang Ying

    2012-01-01

    Arabidopsis thaliana ovate family proteins (AtOFPs) is a newly found plant-specific protein family interacting with TALE (3-aa loop extension homeodomain proteins) homeodomain proteins in Arabidopsis. Here, based on bioinformatic analysis, we found that Arabidopsis genome actually encoded 17 OVATE domain-containing proteins. One of them, AtOFP19, has not been previously identified. Based on their amino acid sequence similarity, AtOFPs proteins can be divided into two groups. Most of the AtOFPs were located in nuclear, four of them were presented in chloroplast and the remaining two members appeared in cytoplasmic. A genome- wide microarray based gene expression analysis involving 47 stages of vegetative and reproductive development revealed that AtOFPs have diverse expression pattems. Investigation of proteins interaction showed that nine AtOFPs only interacted with TALE homeodomain proteins, which are fundamental regulators of plant meristem function and leaf development. Our work could provide important leads toward functional genomics studies of ovate family proteins, which may be involved in a previously unrecognized control mechanism in plant development

  10. The Arabidopsis AtRaptor genes are essential for post-embryonic plant growth

    Directory of Open Access Journals (Sweden)

    Veit Bruce

    2005-04-01

    Full Text Available Abstract Background Flowering plant development is wholly reliant on growth from meristems, which contain totipotent cells that give rise to all post-embryonic organs in the plant. Plants are uniquely able to alter their development throughout their lifespan through the generation of new organs in response to external signals. To identify genes that regulate meristem-based growth, we considered homologues of Raptor proteins, which regulate cell growth in response to nutrients in yeast and metazoans as part of a signaling complex with the target of rapamycin (TOR kinase. Results We identified AtRaptor1A and AtRaptor1B, two loci predicted to encode Raptor proteins in Arabidopsis. Disruption of AtRaptor1B yields plants with a wide range of developmental defects: roots are thick and grow slowly, leaf initiation and bolting are delayed and the shoot inflorescence shows reduced apical dominance. AtRaptor1A AtRaptor1B double mutants show normal embryonic development but are unable to maintain post-embryonic meristem-driven growth. AtRaptor transcripts accumulate in dividing and expanding cells and tissues. Conclusion The data implicate the TOR signaling pathway, a major regulator of cell growth in yeast and metazoans, in the maintenance of growth from the shoot apical meristem in plants. These results provide insights into the ways in which TOR/Raptor signaling has been adapted to regulate plant growth and development, and indicate that in plants, as in other eukaryotes, there is some Raptor-independent TOR activity.

  11. Photorepair mutants of Arabidopsis

    International Nuclear Information System (INIS)

    UV radiation induces two major DNA damage products, the cyclobutane pyrimidine dimer (CPD) and, at a lower frequency, the pyrimidine (6-4) pyrimidinone dimer (6-4 product). Although Escherichia coli and Saccharomyces cerevisiae produce a CPD-specific photolyase that eliminates only this class of dimer, Arabidopsis thaliana, Drosophila melanogaster, Crotalus atrox, and Xenopus laevis have recently been shown to photoreactivate both CPDs and 6-4 products. We describe the isolation and characterization of two new classes of mutants of Arabidopsis, termed uvr2 and uvr3, that are defective in the photoreactivation of CPDs and 6-4 products, respectively. We demonstrate that the CPD photolyase mutation is genetically linked to a DNA sequence encoding a type II (metazoan) CPD photolyase. In addition, we are able to generate plants in which only CPDs or 6-4 products are photoreactivated in the nuclear genome by exposing these mutants to UV light and then allowing them to repair one or the other class of dimers. This provides us with a unique opportunity to study the biological consequences of each of these two major UV-induced photoproducts in an intact living system

  12. Connecting Source with Sink: The Role of Arabidopsis AAP8 in Phloem Loading of Amino Acids.

    Science.gov (United States)

    Santiago, James P; Tegeder, Mechthild

    2016-05-01

    Allocation of large amounts of nitrogen to developing organs occurs in the phloem and is essential for plant growth and seed development. In Arabidopsis (Arabidopsis thaliana) and many other plant species, amino acids represent the dominant nitrogen transport forms in the phloem, and they are mainly synthesized in photosynthetically active source leaves. Following their synthesis, a broad spectrum of the amino nitrogen is actively loaded into the phloem of leaf minor veins and transported within the phloem sap to sinks such as developing leaves, fruits, or seeds. Controlled regulation of the source-to-sink transport of amino acids has long been postulated; however, the molecular mechanism of amino acid phloem loading was still unknown. In this study, Arabidopsis AMINO ACID PERMEASE8 (AAP8) was shown to be expressed in the source leaf phloem and localized to the plasma membrane, suggesting its function in phloem loading. This was further supported by transport studies with aap8 mutants fed with radiolabeled amino acids and by leaf exudate analyses. In addition, biochemical and molecular analyses revealed alterations in leaf nitrogen pools and metabolism dependent on the developmental stage of the mutants. Decreased amino acid phloem loading and partitioning to sinks led to decreased silique and seed numbers, but seed protein levels were unchanged, demonstrating the importance of AAP8 function for sink development rather than seed quality. Overall, these results show that AAP8 plays an important role in source-to-sink partitioning of nitrogen and that its function affects source leaf physiology and seed yield. PMID:27016446

  13. Dataset of Arabidopsis plants that overexpress FT driven by a meristem-specific KNAT1 promoter.

    Science.gov (United States)

    Duplat-Bermúdez, L; Ruiz-Medrano, R; Landsman, D; Mariño-Ramírez, L; Xoconostle-Cázares, B

    2016-09-01

    In this dataset we integrated figures comparing leaf number and rosette diameter in three Arabidopsis FT overexpressor lines (AtFTOE) driven by KNAT1 promoter, "A member of the KNOTTED class of homeodomain proteins encoded by the STM gene of Arabidopsis" [5], vs Wild Type (WT) Arabidopsis plats. Also, presented in the tables are some transcriptomic data obtained by RNA-seq Illumina HiSeq from rosette leaves of Arabidopsis plants of AtFTOE 2.1 line vs WT with accession numbers SRR2094583 and SRR2094587 for AtFTOE replicates 1-3 and AtWT for control replicates 1-2 respectively. Raw data of paired-end sequences are located in the public repository of the National Center for Biotechnology Information of the National Library of Medicine, National Institutes of Health, United States of America, Bethesda, MD, USA as Sequence Read Archive (SRA). Performed analyses of differential expression genes are visualized by Mapman and presented in figures. "Transcriptomic analysis of Arabidopsis overexpressing flowering locus T driven by a meristem-specific promoter that induces early flowering" [2], described the interpretation and discussion of the obtained data. PMID:27366785

  14. 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. PMID:24796562

  15. Leaf spring, and electromagnetic actuator provided with a leaf spring

    NARCIS (Netherlands)

    Berkhoff, Arthur Perry; Lemmen, Remco Louis Christiaan

    2002-01-01

    The invention relates to a leaf spring for an electromagnetic actuator and to such an electromagnetic actuator. The leaf spring is formed as a whole from a disc of plate-shaped, resilient material. The leaf spring comprises a central fastening part, an outer fastening part extending therearound and

  16. Transgenic Arabidopsis Gene Expression System

    Science.gov (United States)

    Ferl, Robert; Paul, Anna-Lisa

    2009-01-01

    The Transgenic Arabidopsis Gene Expression System (TAGES) investigation is one in a pair of investigations that use the Advanced Biological Research System (ABRS) facility. TAGES uses Arabidopsis thaliana, thale cress, with sensor promoter-reporter gene constructs that render the plants as biomonitors (an organism used to determine the quality of the surrounding environment) of their environment using real-time nondestructive Green Fluorescent Protein (GFP) imagery and traditional postflight analyses.

  17. A Potential Role of Flag Leaf Potassium in Conferring Tolerance to Drought-Induced Leaf Senescence in Barley.

    Science.gov (United States)

    Hosseini, Seyed A; Hajirezaei, Mohammad R; Seiler, Christiane; Sreenivasulu, Nese; von Wirén, Nicolaus

    2016-01-01

    Terminal drought stress decreases crop yields by inducing abscisic acid (ABA) and premature leaf senescence. As potassium (K) is known to interfere with ABA homeostasis we addressed the question whether there is genetic variability regarding the role of K nutrition in ABA homeostasis and drought tolerance. To compare their response to drought stress, two barley lines contrasting in drought-induced leaf senescence were grown in a pot experiment under high and low K supply for the analysis of flag leaves from the same developmental stage. Relative to the drought-sensitive line LPR, the line HPR retained more K in its flag leaves under low K supply and showed delayed flag leaf senescence under terminal drought stress. High K retention was further associated with a higher leaf water status, a higher concentration of starch and other primary carbon metabolites. With regard to ABA homeostasis, HPR accumulated less ABA but higher levels of the ABA degradation products phaseic acid (PA) and dehydro-PA. Under K deficiency this went along with higher transcript levels of ABA8'-HYDROXYLASE, encoding a key enzyme in ABA degradation. The present study provides evidence for a positive impact of the K nutritional status on ABA homeostasis and carbohydrate metabolism under drought stress. We conclude that genotypes with a high K nutritional status in the flag leaf show superior drought tolerance by promoting ABA degradation but attenuating starch degradation which delays flag leaf senescence. Flag leaf K levels may thus represent a useful trait for the selection of drought-tolerant barley cultivars. PMID:26955376

  18. A new member of the LIR family from perennial ryegrass is cold-responsive, and promotes vegetative growth in ¤Arabidopsis¤

    DEFF Research Database (Denmark)

    Ciannamea, S.; Jensen, Christian Sig; Agerskov, Henrik;

    2007-01-01

    dusk and declined during the night. Heterologous expression of LpLIR1 in Arabidopsis led to a significant increase in leaf formation under short days (SD) conditions but only when plants had received a preceding vernalization treatment. Furthermore, dissection of plant development under SD revealed a...

  19. Overexpression of a maize SNF-related protein kinase gene, ZmSnRK2.11, reduces salt and drought tolerance in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fan; CHEN Xun-ji; WANG Jian-hua; ZHENG Jun

    2015-01-01

    Sucrose non-fermenting-1 related protein kinase 2 (SnRK2) is a unique family of protein kinases associated with abiotic stress signal transduction in plants. In this study, a maize SnRK2 gene ZmSnRK2.11 was cloned and characterized. The results showed that ZmSnRK2.11 is up-regulated by high-salinity and dehydration treatment, and it is expressed mainly in maize mature leaf. A transient expression assay using onion epidermal cel s revealed that ZmSnRK2.11-GFP fusion proteins are localized to both the nucleus and cytoplasm. Overexpressing-ZmSnRK2.11 in Arabidopsis resulted in salt and drought sensitivity phenotypes that exhibited an increased rate of water loss, reduced relative water content, delayed stoma closure, accumulated less free proline content and increased malondialdehyde (MDA) content relative to the phenotypes observed in wild-type (WT) control. Furthermore, overexpression of ZmSnRK2.11 up-regulated the expression of the genes ABI1 and ABI2 and decreased the expression of DREB2A and P5CS1. Taken together, our results suggest that ZmSnRK2.11 is a possible negative regulator involved in the salt and drought stress signal transduction pathways in plants.

  20. The RPT2 subunit of the 26S proteasome directs complex assembly, histone dynamics, and gametophyte and sporophyte development in Arabidopsis.

    Science.gov (United States)

    Lee, Kwang-Hee; Minami, Atsushi; Marshall, Richard S; Book, Adam J; Farmer, Lisa M; Walker, Joseph M; Vierstra, Richard D

    2011-12-01

    The regulatory particle (RP) of the 26S proteasome contains a heterohexameric ring of AAA-ATPases (RPT1-6) that unfolds and inserts substrates into the core protease (CP) for degradation. Through genetic analysis of the Arabidopsis thaliana gene pair encoding RPT2, we show that this subunit plays a critical role in 26S proteasome assembly, histone dynamics, and plant development. rpt2a rpt2b double null mutants are blocked in both male and female gamete transmission, demonstrating that the subunit is essential. Whereas rpt2b mutants are phenotypically normal, rpt2a mutants display a range of defects, including impaired leaf, root, trichome, and pollen development, delayed flowering, stem fasciation, hypersensitivity to mitomycin C and amino acid analogs, hyposensitivity to the proteasome inhibitor MG132, and decreased 26S complex stability. The rpt2a phenotype can be rescued by both RPT2a and RPT2b, indicative of functional redundancy, but not by RPT2a mutants altered in ATP binding/hydrolysis or missing the C-terminal hydrophobic sequence that docks the RPT ring onto the CP. Many rpt2a phenotypes are shared with mutants lacking the chromatin assembly factor complex CAF1. Like caf1 mutants, plants missing RPT2a or reduced in other RP subunits contain less histones, thus implicating RPT2 specifically, and the 26S proteasome generally, in plant nucleosome assembly. PMID:22158466

  1. Nitrate metabolism in tobacco leaves overexpressing Arabidopsis nitrite reductase.

    Science.gov (United States)

    Davenport, Susie; Le Lay, Pascaline; Sanchez-Tamburrrino, Juan Pablo

    2015-12-01

    Primary nitrogen assimilation in plants includes the reduction of nitrite to ammonium in the chloroplasts by the enzyme nitrite reductase (NiR EC:1.7.7.1) or in the plastids of non-photosynthetic organs. Here we report on a study overexpressing the Arabidopsis thaliana NiR (AtNiR) gene in tobacco plants under the control of a constitutive promoter (CERV - Carnation Etched Ring Virus). The aim was to overexpress AtNiR in an attempt to alter the level of residual nitrite in the leaf which can act as precursor to the formation of nitrosamines. The impact of increasing the activity of AtNiR produced an increase in leaf protein and a stay-green phenotype in the primary transformed AtNiR population. Investigation of the T1 homozygous population demonstrated elevated nitrate reductase (NR) activity, reductions in leaf nitrite and nitrate and the amino acids proline, glutamine and glutamate. Chlorophyl content of the transgenic lines was increased, as evidenced by the stay-green phenotype. This reveals the importance of NiR in primary nitrogen assimilation and how modification of this key enzyme affects both the nitrogen and carbon metabolism of tobacco plants. PMID:26447683

  2. Rapid endocytosis is triggered upon imbibition in Arabidopsis seeds.

    Science.gov (United States)

    Pagnussat, Luciana; Burbach, Christian; Baluška, František; de la Canal, Laura

    2012-03-01

    During seed imbibition and embryo activation, rapid change from a metabolically resting state to the activation of diverse extracellular and/or membrane bound molecules is essential and, hence, endocytosis could be activated too. In fact, we have documented endocytic internalization of the membrane impermeable endocytic tracer FM4-64 already upon 30 min of imbibition of Arabidopsis seeds. This finding suggest that endocytosis is activated early during seed imbibition in Arabidopsis. Immunolocalization of rhamnogalacturonan-II (RG-II) complexed with boron showed that whereas this pectin is localized only in the cell walls of dry seed embryos, it starts to be intracellular once the imbibition started. Brefeldin A (BFA) exposure resulted in recruitment of the intracellular RG-II pectin complexes into the endocytic BFA-induced compartments, confirming the endocytic origin of the RG-II signal detected intracellularly. Finally, germination was significantly delayed when Arabidopsis seeds were germinated in the presence of inhibitors of endocytic pathways, suggesting that trafficking of extracellular molecules might play an important role in the overcome of germination. This work constitutes the first demonstration of endocytic processes during germination and opens new perspectives about the role of the extracellular matrix and membrane components in seed germination. PMID:22476454

  3. Rapid expression of transgenes driven by seed-specific constructs in leaf tissue: DHA production

    Directory of Open Access Journals (Sweden)

    Zhou Xue-Rong

    2010-03-01

    Full Text Available Abstract Background Metabolic engineering of seed biosynthetic pathways to diversify and improve crop product quality is a highly active research area. The validation of genes driven by seed-specific promoters is time-consuming since the transformed plants must be grown to maturity before the gene function can be analysed. Results In this study we demonstrate that genes driven by seed-specific promoters contained within complex constructs can be transiently-expressed in the Nicotiana benthamiana leaf-assay system by co-infiltrating the Arabidopsis thaliana LEAFY COTYLEDON2 (LEC2 gene. A real-world case study is described in which we first assembled an efficient transgenic DHA synthesis pathway using a traditional N. benthamiana Cauliflower Mosaic Virus (CaMV 35S-driven leaf assay before using the LEC2-extended assay to rapidly validate a complex seed-specific construct containing the same genes before stable transformation in Arabidopsis. Conclusions The LEC2-extended N. benthamiana assay allows the transient activation of seed-specific promoters in leaf tissue. In this study we have used the assay as a rapid preliminary screen of a complex seed-specific transgenic construct prior to stable transformation, a feature that will become increasingly useful as genetic engineering moves from the manipulation of single genes to the engineering of complex pathways. We propose that the assay will prove useful for other applications wherein rapid expression of transgenes driven by seed-specific constructs in leaf tissue are sought.

  4. Leaf absorbance and photosynthesis

    Science.gov (United States)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  5. An Analytical Delay Model

    Institute of Scientific and Technical Information of China (English)

    MIN Yinghua; LI Zhongcheng

    1999-01-01

    Delay consideration has been a majorissue in design and test of high performance digital circuits. Theassumption of input signal change occurring only when all internal nodesare stable restricts the increase of clock frequency. It is no longertrue for wave pipelining circuits. However, previous logical delaymodels are based on the assumption. In addition, the stable time of arobust delay test generally depends on the longest sensitizable pathdelay. Thus, a new delay model is desirable. This paper explores thenecessity first. Then, Boolean process to analytically describe thelogical and timing behavior of a digital circuit is reviewed. Theconcept of sensitization is redefined precisely in this paper. Based onthe new concept of sensitization, an analytical delay model isintroduced. As a result, many untestable delay faults under thelogical delay model can be tested if the output waveforms can be sampledat more time points. The longest sensitizable path length is computedfor circuit design and delay test.

  6. Contact rate modulates foraging efficiency in leaf cutting ants

    OpenAIRE

    S. Bouchebti; Ferrere, S.; Vittori, K.; LATIL, G.; Dussutour, A; Fourcassié, V.

    2015-01-01

    Lane segregation is rarely observed in animals that move in bidirectional flows. Consequently, these animals generally experience a high rate of head-on collisions during their journeys. Although these collisions have a cost (each collision induces a delay resulting in a decrease of individual speed), they could also have a benefit by promoting information transfer between individuals. Here we explore the impact of head-on collisions in leaf-cutting ants moving on foraging trails by artificia...

  7. The Effect of Leaf Litter Cover on Surface Runoff and Soil Erosion in Northern China

    OpenAIRE

    Li, Xiang; Niu, Jianzhi; Xie, Baoyuan

    2014-01-01

    The role of leaf litter in hydrological processes and soil erosion of forest ecosystems is poorly understood. A field experiment was conducted under simulated rainfall in runoff plots with a slope of 10%. Two common types of litter in North China (from Quercus variabilis, representing broadleaf litter, and Pinus tabulaeformis, representing needle leaf litter), four amounts of litter, and five rainfall intensities were tested. Results revealed that the litter reduced runoff and delayed the beg...

  8. Leaf-to-leaf distances in Catalan tree graphs

    OpenAIRE

    Goldsborough, Andrew M.; Fellows, Jonathan M; Bates, Matthew; Rautu, S. Alex; Rowlands, George; Römer, Rudolf A.

    2015-01-01

    We study the average leaf-to-leaf path lengths on ordered Catalan tree graphs with $n$ nodes and show that these are equivalent to the average length of paths starting from the root node. We give an explicit analytic formula for the average leaf-to-leaf path length as a function of separation of the leaves and study its asymptotic properties. At the heart of our method is a strategy based on an abstract graph representation of generating functions which we hope can be useful also in other con...

  9. Multiple components are integrated to determine leaf complexity in Lotus japonicus.

    Science.gov (United States)

    Wang, Zhenhua; Chen, Jianghua; Weng, Lin; Li, Xin; Cao, Xianglin; Hu, Xiaohe; Luo, Da; Yang, Jun

    2013-05-01

    Transcription factors and phytohormones have been reported to play crucial roles to regulate leaf complexity among plant species. Using the compound-leafed species Lotus japonicus, a model legume plant with five visible leaflets, we characterized four independent mutants with reduced leaf complexity, proliferating floral meristem (pfm), proliferating floral organ-2 (pfo-2), fused leaflets1 (ful1) and umbrella leaflets (uml), which were further identified as loss-of-function mutants of Arabidopsis orthologs LEAFY (LFY), UNUSUAL FLORAL ORGANS (UFO), CUP-SHAPED COTYLEDON 2 (CUC2) and PIN-FORMED 1 (PIN1), respectively. Comparing the leaf development of wild-type and mutants by a scanning electron microscopy approach, leaflet initiation and/or dissection were found to be affected in these mutants. Expression and phenotype analysis indicated that PFM/LjLFY and PFO/LjUFO determined the basipetal leaflet initiation manner in L. japonicus. Genetic analysis of ful1 and uml mutants and their double mutants revealed that the CUC2-like gene and auxin pathway also participated in leaflet dissection in L. japonicus, and their functions might influence cytokinin biogenesis directly or indirectly. Our results here suggest that multiple genes were interplayed and played conserved functions in controlling leaf complexity during compound leaf development in L. japonicus. PMID:23331609

  10. Functional analysis of the theobroma cacao NPR1 gene in arabidopsis

    Directory of Open Access Journals (Sweden)

    Verica Joseph

    2010-11-01

    Full Text Available Abstract Background The Arabidopsis thaliana NPR1 gene encodes a transcription coactivator (NPR1 that plays a major role in the mechanisms regulating plant defense response. After pathogen infection and in response to salicylic acid (SA accumulation, NPR1 translocates from the cytoplasm into the nucleus where it interacts with other transcription factors resulting in increased expression of over 2000 plant defense genes contributing to a pathogen resistance response. Results A putative Theobroma cacao NPR1 cDNA was isolated by RT-PCR using degenerate primers based on homologous sequences from Brassica, Arabidopsis and Carica papaya. The cDNA was used to isolate a genomic clone from Theobroma cacao containing a putative TcNPR1 gene. DNA sequencing revealed the presence of a 4.5 kb coding region containing three introns and encoding a polypeptide of 591 amino acids. The predicted TcNPR1 protein shares 55% identity and 78% similarity to Arabidopsis NPR1, and contains each of the highly conserved functional domains indicative of this class of transcription factors (BTB/POZ and ankyrin repeat protein-protein interaction domains and a nuclear localization sequence (NLS. To functionally define the TcNPR1 gene, we transferred TcNPR1 into an Arabidopsis npr1 mutant that is highly susceptible to infection by the plant pathogen Pseudomonas syringae pv. tomato DC3000. Driven by the constitutive CaMV35S promoter, the cacao TcNPR1 gene partially complemented the npr1 mutation in transgenic Arabidopsis plants, resulting in 100 fold less bacterial growth in a leaf infection assay. Upon induction with SA, TcNPR1 was shown to translocate into the nucleus of leaf and root cells in a manner identical to Arabidopsis NPR1. Cacao NPR1 was also capable of participating in SA-JA signaling crosstalk, as evidenced by the suppression of JA responsive gene expression in TcNPR1 overexpressing transgenic plants. Conclusion Our data indicate that the TcNPR1 is a functional

  11. The IBR5 phosphatase promotes Arabidopsis auxin responses through a novel mechanism distinct from TIR1-mediated repressor degradation

    OpenAIRE

    Bartel Bonnie; Monroe-Augustus Melanie; Strader Lucia C

    2008-01-01

    Abstract Background In Arabidopsis, INDOLE-3-BUTYRIC ACID RESPONSE5 (IBR5), a putative dual-specificity protein phosphatase, is a positive regulator of auxin response. Mutations in IBR5 result in decreased plant height, defective vascular development, increased leaf serration, fewer lateral roots, and resistance to the phytohormones auxin and abscisic acid. However, the pathways through which IBR5 influences auxin responses are not fully understood. Results We analyzed double mutants of ibr5 ...

  12. Yeast Cell Wall Extract Induces Disease Resistance against Bacterial and Fungal Pathogens in Arabidopsis thaliana and Brassica Crop

    OpenAIRE

    Narusaka, Mari; Minami, Taichi; Iwabuchi, Chikako; Hamasaki, Takashi; Takasaki, Satoko; Kawamura, Kimito; Narusaka, Yoshihiro

    2015-01-01

    Housaku Monogatari (HM) is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated incre...

  13. Differences in photosynthesis and terpene content in leaves and roots of wild-type and transgenic Arabidopsis thaliana plants

    OpenAIRE

    Blanch Roure, Josep-Salvador; Peñuelas, Josep; Llusià Benet, Joan; Sardans i Galobart, Jordi; Owen, Susan M.

    2015-01-01

    We investigated the hypotheses that two different varieties of Arabidopsis thaliana show differences in physiology and terpene production. The two varieties of A. thaliana used in this study were wildtype (WT) and transgenic line (CoxIVFaNES I) genetically modified to emit nerolidol with linalool/nerolidol synthase (COX). Photosynthetic rate, electron transport rate, fluorescence, leaf volatile terpene contents and root volatile terpene contents were analyzed. For both types, we found coeluti...

  14. Post-translational regulation and trafficking of the granulin-containing protease RD21 of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Christian Gu

    Full Text Available RD21-like proteases are ubiquitous, plant-specific papain-like proteases typified by carrying a C-terminal granulin domain. RD21-like proteases are involved in immunity and associated with senescence and various types of biotic and abiotic stresses. Here, we interrogated Arabidopsis RD21 regulation and trafficking by site-directed mutagenesis, agroinfiltration, western blotting, protease activity profiling and protein degradation. Using an introduced N-glycan sensor, deglycosylation experiments and glyco-engineered N. benthamiana plants, we show that RD21 passes through the Golgi where it becomes fucosylated. Our studies demonstrate that RD21 is regulated at three post-translational levels. Prodomain removal is not blocked in the catalytic Cys mutant, indicating that RD21 is activated by a proteolytic cascade. However, RD21 activation in Arabidopsis does not require vacuolar processing enzymes (VPEs or aleurain-like protease AALP. In contrast, granulin domain removal requires the catalytic Cys and His residues and is therefore autocatalytic. Furthermore, SDS can (re-activate latent RD21 in Arabidopsis leaf extracts, indicating the existence of a third layer of post-translational regulation, possibly mediated by endogenous inhibitors. RD21 causes a dominant protease activity in Arabidopsis leaf extracts, responsible for SDS-induced proteome degradation.

  15. Studies on the Rice LEAF INCLINATION1 (LC1),an IAA-amido Synthetase, Reveal the Effects of Auxin in Leaf Inclination Control

    Institute of Scientific and Technical Information of China (English)

    Shu-Qing Zhao; Jing-Jing Xiang; Hong-Wei Xue

    2013-01-01

    The angle of rice leaf inclination is an important agronomic trait and closely related to the yields and architecture of crops.Although few mutants with altered leaf angles have been reported,the molecular mechanism remains to be elucidated,especially whether hormones are involved in this process.Through genetic screening,a rice gain-offunction mutant leaf inclination1,Ic1-D,was identified from the Shanghai T-DNA Insertion Population (SHIP).Phenotypic analysis confirmed the exaggerated leaf angles of Ic1-D due to the stimulated cell elongation at the lamina joint.LC1 is transcribed in various tissues and encodes OsGH3-1,an indole-3-acetic acid (IAA) amido synthetase,whose homolog of Arabidopsis functions in maintaining the auxin homeostasis by conjugating excess IAA to various amino acids.Indeed,recombinant LC1 can catalyze the conjugation of IAA to Ala,Asp,and Asn in vitro,which is consistent with the decreased free IAA amount in Ic1-D mutant.Ic1-D is insensitive to IAA and hypersensitive to exogenous BR,in agreement with the microarray analysis that reveals the altered transcriptions of genes involved in auxin signaling and BR biosynthesis.These results indicate the crucial roles of auxin homeostasis in the leaf inclination control.

  16. Delayed Gambler's Ruin

    CERN Document Server

    Imai, Tomohisa

    2016-01-01

    We present here a new extended model of the gambler's ruin problem by incorporating delays in receiving of rewards and paying of penalties. When there is a difference between two delays, an exact analysis of the ruin probability is difficult. We derive an approximate scheme to find an effective shift in the initial assets of the gambler. Through comparison against computer simulations, this approximation is shown to work for small differences between the two delays.

  17. 7 CFR 29.2528 - Leaf.

    Science.gov (United States)

    2010-01-01

    ...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2528 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.2528 Section 29.2528 Agriculture...

  18. VARIABLE TIME DELAY MEANS

    Science.gov (United States)

    Clemensen, R.E.

    1959-11-01

    An electrically variable time delay line is described which may be readily controlled simuitaneously with variable impedance matching means coupied thereto such that reflections are prevented. Broadly, the delay line includes a signal winding about a magnetic core whose permeability is electrically variable. Inasmuch as the inductance of the line varies directly with the permeability, the time delay and characteristic impedance of the line both vary as the square root of the permeability. Consequently, impedance matching means may be varied similariy and simultaneously w:th the electrically variable permeability to match the line impedance over the entire range of time delay whereby reflections are prevented.

  19. BODYGUARD is required for the biosynthesis of cutin in Arabidopsis.

    Science.gov (United States)

    Jakobson, Liina; Lindgren, Leif Ove; Verdier, Gaëtan; Laanemets, Kristiina; Brosché, Mikael; Beisson, Fred; Kollist, Hannes

    2016-07-01

    The cuticle plays a critical role in plant survival during extreme drought conditions. There are, however, surprisingly, many gaps in our understanding of cuticle biosynthesis. An Arabidopsis thaliana T-DNA mutant library was screened for mutants with enhanced transpiration using a simple condensation spot method. Five mutants, named cool breath (cb), were isolated. The cb5 mutant was found to be allelic to bodyguard (bdg), which is affected in an α/β-hydrolase fold protein important for cuticle structure. The analysis of cuticle components in cb5 (renamed as bdg-6) and another T-DNA mutant allele (bdg-7) revealed no impairment in wax synthesis, but a strong decrease in total cutin monomer load in young leaves and flowers. Root suberin content was also reduced. Overexpression of BDG increased total leaf cutin monomer content nearly four times by affecting preferentially C18 polyunsaturated ω-OH fatty acids and dicarboxylic acids. Whole-plant gas exchange analysis showed that bdg-6 had higher cuticular conductance and rate of transpiration; however, plant lines overexpressing BDG resembled the wild-type with regard to these characteristics. This study identifies BDG as an important component of the cutin biosynthesis machinery in Arabidopsis. We also show that, using BDG, cutin can be greatly modified without altering the cuticular water barrier properties and transpiration. PMID:26990896

  20. Posttranslational modifications of FERREDOXIN-NADP+ OXIDOREDUCTASE in Arabidopsis chloroplasts.

    Science.gov (United States)

    Lehtimäki, Nina; Koskela, Minna M; Dahlström, Käthe M; Pakula, Eveliina; Lintala, Minna; Scholz, Martin; Hippler, Michael; Hanke, Guy T; Rokka, Anne; Battchikova, Natalia; Salminen, Tiina A; Mulo, Paula

    2014-12-01

    Rapid responses of chloroplast metabolism and adjustments to photosynthetic machinery are of utmost importance for plants' survival in a fluctuating environment. These changes may be achieved through posttranslational modifications of proteins, which are known to affect the activity, interactions, and localization of proteins. Recent studies have accumulated evidence about the crucial role of a multitude of modifications, including acetylation, methylation, and glycosylation, in the regulation of chloroplast proteins. Both of the Arabidopsis (Arabidopsis thaliana) leaf-type FERREDOXIN-NADP(+) OXIDOREDUCTASE (FNR) isoforms, the key enzymes linking the light reactions of photosynthesis to carbon assimilation, exist as two distinct forms with different isoelectric points. We show that both AtFNR isoforms contain multiple alternative amino termini and undergo light-responsive addition of an acetyl group to the α-amino group of the amino-terminal amino acid of proteins, which causes the change in isoelectric point. Both isoforms were also found to contain acetylation of a conserved lysine residue near the active site, while no evidence for in vivo phosphorylation or glycosylation was detected. The dynamic, multilayer regulation of AtFNR exemplifies the complex regulatory network systems controlling chloroplast proteins by a range of posttranslational modifications, which continues to emerge as a novel area within photosynthesis research. PMID:25301888

  1. Piriformospora indica Stimulates Root Metabolism of Arabidopsis thaliana.

    Science.gov (United States)

    Strehmel, Nadine; Mönchgesang, Susann; Herklotz, Siska; Krüger, Sylvia; Ziegler, Jörg; Scheel, Dierk

    2016-01-01

    Piriformospora indica is a root-colonizing fungus, which interacts with a variety of plants including Arabidopsis thaliana. This interaction has been considered as mutualistic leading to growth promotion of the host. So far, only indolic glucosinolates and phytohormones have been identified as key players. In a comprehensive non-targeted metabolite profiling study, we analyzed Arabidopsis thaliana's roots, root exudates, and leaves of inoculated and non-inoculated plants by ultra performance liquid chromatography/electrospray ionization quadrupole-time-of-flight mass spectrometry (UPLC/(ESI)-QTOFMS) and gas chromatography/electron ionization quadrupole mass spectrometry (GC/EI-QMS), and identified further biomarkers. Among them, the concentration of nucleosides, dipeptides, oligolignols, and glucosinolate degradation products was affected in the exudates. In the root profiles, nearly all metabolite levels increased upon co-cultivation, like carbohydrates, organic acids, amino acids, glucosinolates, oligolignols, and flavonoids. In the leaf profiles, we detected by far less significant changes. We only observed an increased concentration of organic acids, carbohydrates, ascorbate, glucosinolates and hydroxycinnamic acids, and a decreased concentration of nitrogen-rich amino acids in inoculated plants. These findings contribute to the understanding of symbiotic interactions between plant roots and fungi of the order of Sebacinales and are a valid source for follow-up mechanistic studies, because these symbioses are particular and clearly different from interactions of roots with mycorrhizal fungi or dark septate endophytes. PMID:27399695

  2. Effect of Plant Growth Regulators on Leaf Number, Leaf Area and Leaf Dry Matter in Grape

    OpenAIRE

    Zahoor Ahmad BHAT; Rizwan RASHID; Javid Ahmad BHAT

    2011-01-01

    Influence of phenylureas (CPPU) and brassinosteriod (BR) along with GA (gibberellic acid) were studied on seedless grape vegetative characteristics like leaf number, leaf area and leaf dry matter. Growth regulators were sprayed on the vines either once (7 days after fruit set or 15 days after fruit set) or twice (7+15 days after fruit set). CPPU 2 ppm+BR 0.4 ppm+GA 25 ppm produced maximum number of leaves (18.78) while as untreated vines produced least leaf number (16.22) per shoot. Maximum l...

  3. The artificial leaf.

    Science.gov (United States)

    Nocera, Daniel G

    2012-05-15

    To convert the energy of sunlight into chemical energy, the leaf splits water via the photosynthetic process to produce molecular oxygen and hydrogen, which is in a form of separated protons and electrons. The primary steps of natural photosynthesis involve the absorption of sunlight and its conversion into spatially separated electron-hole pairs. The holes of this wireless current are captured by the oxygen evolving complex (OEC) of photosystem II (PSII) to oxidize water to oxygen. The electrons and protons produced as a byproduct of the OEC reaction are captured by ferrodoxin of photosystem I. With the aid of ferrodoxin-NADP(+) reductase, they are used to produce hydrogen in the form of NADPH. For a synthetic material to realize the solar energy conversion function of the leaf, the light-absorbing material must capture a solar photon to generate a wireless current that is harnessed by catalysts, which drive the four electron/hole fuel-forming water-splitting reaction under benign conditions and under 1 sun (100 mW/cm(2)) illumination. This Account describes the construction of an artificial leaf comprising earth-abundant elements by interfacing a triple junction, amorphous silicon photovoltaic with hydrogen- and oxygen-evolving catalysts made from a ternary alloy (NiMoZn) and a cobalt-phosphate cluster (Co-OEC), respectively. The latter captures the structural and functional attributes of the PSII-OEC. Similar to the PSII-OEC, the Co-OEC self-assembles upon oxidation of an earth-abundant metal ion from 2+ to 3+, may operate in natural water at room temperature, and is self-healing. The Co-OEC also activates H(2)O by a proton-coupled electron transfer mechanism in which the Co-OEC is increased by four hole equivalents akin to the S-state pumping of the Kok cycle of PSII. X-ray absorption spectroscopy studies have established that the Co-OEC is a structural relative of Mn(3)CaO(4)-Mn cubane of the PSII-OEC, where Co replaces Mn and the cubane is extended in a

  4. Dynamic Network Delay Cartography

    CERN Document Server

    Rajawat, Ketan; Giannakis, Georgios B

    2012-01-01

    Path delays in IP networks are important metrics, required by network operators for assessment, planning, and fault diagnosis. Monitoring delays of all source-destination pairs in a large network is however challenging and wasteful of resources. The present paper advocates a spatio-temporal Kalman filtering approach to construct network-wide delay maps using measurements on only a few paths. The proposed network cartography framework allows efficient tracking and prediction of delays by relying on both topological as well as historical data. Optimal paths for delay measurement are selected in an online fashion by leveraging the notion of submodularity. The resulting predictor is optimal in the class of linear predictors, and outperforms competing alternatives on real-world datasets.

  5. Deterministically delayed pseudofractal networks

    International Nuclear Information System (INIS)

    On the basis of pseudofractal networks (PFNs), we propose a family of delayed pseudofractal networks (DPFNs) with a special feature that newly added edges delay producing new nodes, differing from the evolution algorithms of PFNs where all existing edges simultaneously generate new nodes. We obtain analytical formulae for degree distribution, clustering coefficient (C) and average path length (APL). We compare DPFNs and PFNs, and show that the exponent of the degree distribution of DPFNs is smaller than that of PFNs, meaning that the heterogeneity of this kind of delayed network is higher. Compared to PFNs, small-world features of DPFNs are more prominent (larger C and smaller APL). We also find that the delay strengthens the scale-free and small-world characteristics of DPFNs. In addition, we calculate and compare the mean first passage time (MFPT) numerically, revealing that the MFPT of DPFNs is shorter. Our study may help with a deeper understanding of various deterministically growing delayed networks

  6. STENOFOLIA acts as a repressor in regulating leaf blade outgrowth.

    Science.gov (United States)

    Lin, Hao; Niu, Lifang; Tadege, Million

    2013-06-01

    We recently reported that the Medicago WOX gene, STENOFOLIA (STF), acts as a transcriptional repressor in regulating leaf blade outgrowth. By using the Nicotiana sylvestris bladeless lam1 mutant as a genetic tool, we showed that the WUS-box, which is conserved among WUS clade WOX genes, is partly responsible for the repressive activity of STF. All members of the modern/WUS clade genes (WUS, WOX1-WOX7) in Arabidopsis that contain intact WUS-box can substitute for STF/LAM1 function while the intermediate and ancient clade members including WOX9,WOX11 and WOX13 cannot, due to lack of the intact WUS-box. Taken together, our results reveal a conserved repression mechanism playing a central role in cell proliferation conferred to the evolutionarily dynamic WOX gene family with acquisition of a repressor domain. PMID:23603965

  7. CURLY LEAF Regulates Gene Sets Coordinating Seed Size and Lipid Biosynthesis1[OPEN

    Science.gov (United States)

    Wang, Huan; Ye, Jian; Wu, Hui-Wen; Sun, Hai-Xi; Chua, Nam-Hai

    2016-01-01

    CURLY LEAF (CLF), a histone methyltransferase of Polycomb Repressive Complex 2 (PRC2) for trimethylation of histone H3 Lys 27 (H3K27me3), has been thought as a negative regulator controlling mainly postgermination growth in Arabidopsis (Arabidopsis thaliana). Approximately 14% to 29% of genic regions are decorated by H3K27me3 in the Arabidopsis genome; however, transcriptional repression activities of PRC2 on a majority of these regions remain unclear. Here, by analysis of transcriptome profiles, we found that approximately 11.6% genes in the Arabidopsis genome were repressed by CLF in various organs. Unexpectedly, approximately 54% of these genes were preferentially repressed in siliques. Further analyses of 118 transcriptome datasets uncovered a group of genes that was preferentially expressed and repressed by CLF in embryos at the mature-green stage. This observation suggests that CLF mediates a large-scale H3K27me3 programming/reprogramming event during embryonic development. Plants of clf-28 produced bigger and heavier seeds with higher oil content, larger oil bodies, and altered long-chain fatty acid composition compared with wild type. Around 46% of CLF-repressed genes were associated with H3K27me3 marks; moreover, we verified histone modification and transcriptional repression by CLF on regulatory genes. Our results suggest that CLF silences specific gene expression modules. Genes operating within a module have various molecular functions, but they cooperate to regulate a similar physiological function during embryo development. PMID:26945048

  8. HANABA TARANU regulates the shoot apical meristem and leaf development in cucumber (Cucumis sativus L.).

    Science.gov (United States)

    Ding, Lian; Yan, Shuangshuang; Jiang, Li; Liu, Meiling; Zhang, Juan; Zhao, Jianyu; Zhao, Wensheng; Han, Ying-Yan; Wang, Qian; Zhang, Xiaolan

    2015-12-01

    The shoot apical meristem (SAM) is essential for continuous organogenesis in higher plants, while the leaf is the primary source organ and the leaf shape directly affects the efficiency of photosynthesis. HANABA TARANU (HAN) encodes a GATA3-type transcription factor that functions in floral organ development, SAM organization, and embryo development in Arabidopsis, but is involved in suppressing bract outgrowth and promoting branching in grass species. Here the function of the HAN homologue CsHAN1 was characterized in cucumber, an important vegetable with great agricultural and economic value. CsHAN1 is predominantly expressed at the junction of the SAM and the stem, and can partially rescue the han-2 floral organ phenotype in Arabidopsis. Overexpression and RNAi of CsHAN1 transgenic cucumber resulted in retarded growth early after embryogenesis and produced highly lobed leaves. Further, it was found that CsHAN1 may regulate SAM development through regulating the WUSCHEL (WUS) and SHOOT MERISTEMLESS (STM) pathways, and mediate leaf development through a complicated gene regulatory network in cucumber. PMID:26320238

  9. Early Autumn Senescence in Red Maple (Acer rubrum L. Is Associated with High Leaf Anthocyanin Content

    Directory of Open Access Journals (Sweden)

    Rachel Anderson

    2015-08-01

    Full Text Available Several theories exist about the role of anthocyanins in senescing leaves. To elucidate factors contributing to variation in autumn leaf anthocyanin contents among individual trees, we analysed anthocyanins and other leaf traits in 27 individuals of red maple (Acer rubrum L. over two growing seasons in the context of timing of leaf senescence. Red maple usually turns bright red in the autumn, but there is considerable variation among the trees. Leaf autumn anthocyanin contents were consistent between the two years of investigation. Autumn anthocyanin content strongly correlated with degree of chlorophyll degradation mid to late September, early senescing leaves having the highest concentrations of anthocyanins. It also correlated positively with leaf summer chlorophyll content and dry matter content, and negatively with specific leaf area. Time of leaf senescence and anthocyanin contents correlated with soil pH and with canopy openness. We conclude that the importance of anthocyanins in protection of leaf processes during senescence depends on the time of senescence. Rather than prolonging the growing season by enabling a delayed senescence, autumn anthocyanins in red maple in Ontario are important when senescence happens early, possibly due to the higher irradiance and greater danger of oxidative damage early in the season.

  10. Delay in Contests

    OpenAIRE

    Bester, Helmut; Konrad, Kai A.

    2003-01-01

    "Why is there delay in contests? In this paper we follow and extend the line of reasoning of Carl von Clausewitz to explain delay. For a given contest technology, delay may occur if there is an asymmetry between defense and attack, if the expected change in relative strengths is moderate, and if the additional cost of investment in future strength is low." (author's abstract) "In Konfliktsituationen findet der 'showdown' häufig mit einer Verzögerung statt. Das ist überraschend, weil sich m...

  11. Leaf segmentation in plant phenotyping

    NARCIS (Netherlands)

    Scharr, Hanno; Minervini, Massimo; French, Andrew P.; Klukas, Christian; Kramer, David M.; Liu, Xiaoming; Luengo, Imanol; Pape, Jean Michel; Polder, Gerrit; Vukadinovic, Danijela; Yin, Xi; Tsaftaris, Sotirios A.

    2016-01-01

    Image-based plant phenotyping is a growing application area of computer vision in agriculture. A key task is the segmentation of all individual leaves in images. Here we focus on the most common rosette model plants, Arabidopsis and young tobacco. Although leaves do share appearance and shape cha

  12. Arabidopsis thaliana—Aphid Interaction

    OpenAIRE

    Louis, Joe; Singh, Vijay,; Shah, Jyoti

    2012-01-01

    Aphids are important pests of plants that use their stylets to tap into the sieve elements to consume phloem sap. Besides the removal of photosynthates, aphid infestation also alters source-sink patterns. Most aphids also vector viral diseases. In this chapter, we will summarize on recent significant findings in plant-aphid interaction, and how studies involving Arabidopsis thaliana and Myzus persicae (Sülzer), more commonly known as the green peach aphid (GPA), are beginning to provide impor...

  13. Selenium Speciation in Arabidopsis Thaliana

    OpenAIRE

    Wang, Xiaoou

    2011-01-01

    Selenium has been proved as an essential micronutrient and is beneficial to animals and humans. It is a structural component of the important antioxidant enzyme, glutathione peroxidase, which catalyzes reactions to detoxify reactive oxygen species. However, the essentiality of Se in plants remains controversial and the protective role of Se in plants has rarely been investigated. In this study, Arabidopsis thaliana was grown in controlled environments having selenate or selenite enriched medi...

  14. Stem cell organization in Arabidopsis

    OpenAIRE

    Wendrich, J.R.

    2016-01-01

    Growth of plant tissues and organs depends on continuous production of new cells, by niches of stem cells. Stem cells typically divide to give rise to one differentiating daughter and one non-differentiating daughter. This constant process of self-renewal ensures that the niches of stem cells or meristems stay active throughout plant-life. Specification of stem cells occurs very early during development of the emrbyo and they are maintained during later stages. The Arabidopsis embryo is a hig...

  15. Leaf Relative Water Content Estimated from Leaf Reflectance and Transmittance

    Science.gov (United States)

    Vanderbilt, Vern; Daughtry, Craig; Dahlgren, Robert

    2016-01-01

    Remotely sensing the water status of plants and the water content of canopies remain long term goals of remote sensing research. In the research we report here, we used optical polarization techniques to monitor the light reflected from the leaf interior, R, as well as the leaf transmittance, T, as the relative water content (RWC) of corn (Zea mays) leaves decreased. Our results show that R and T both change nonlinearly. The result show that the nonlinearities cancel in the ratio R/T, which appears linearly related to RWC for RWC less than 90%. The results suggest that potentially leaf water status and perhaps even canopy water status could be monitored starting from leaf and canopy optical measurements.

  16. Regulation of Compound Leaf Development

    Directory of Open Access Journals (Sweden)

    Yuan Wang

    2013-12-01

    Full Text Available Leaf morphology is one of the most variable, yet inheritable, traits in the plant kingdom. How plants develop a variety of forms and shapes is a major biological question. Here, we discuss some recent progress in understanding the development of compound or dissected leaves in model species, such as tomato (Solanum lycopersicum, Cardamine hirsuta and Medicago truncatula, with an emphasis on recent discoveries in legumes. We also discuss progress in gene regulations and hormonal actions in compound leaf development. These studies facilitate our understanding of the underlying regulatory mechanisms and put forward a prospective in compound leaf studies.

  17. STATIC ANALYSIS OF LEAF SPRING

    OpenAIRE

    E VENUGOPAL GOUD; G HARINATH GOWD

    2012-01-01

    Leaf springs are special kind of springs used in automobile suspension systems. The advantage of leaf spring over helical spring is that the ends of the spring may be guided along a definite path as it deflects to act as a structural member in addition to energy absorbing device. The main function of leaf spring is not only tosupport vertical load but also to isolate road induced vibrations. It is subjected to millions of load cycles leading to fatigue failure. Static analysis determines the ...

  18. commensurate point delays

    Directory of Open Access Journals (Sweden)

    M. de la Sen

    2005-01-01

    nominal controller is maintained. In the current approach, the finite spectrum assignment is only considered as a particular case of the designer's choice of a (delay-dependent arbitrary spectrum assignment objective.

  19. Vernier Delay Unit

    International Nuclear Information System (INIS)

    This module will accept differential ECL pulses from the auxiliary rear panel or NIM level pulses from the front panel. The pulses are produced at the output with a fixed delay that is software programmable in steps of 0.1 ns over the range of 0.1 to 10.5 ns. Multiple outputs are available at the front panel. Minimum delay through the module is 9 ns

  20. Delayed Product Introduction

    OpenAIRE

    Kai-Lung Hui; Qiu-Hong Wang

    2005-01-01

    We investigate the incentives of a monopolistic seller to delay the introduction of a new and improved version of his product. By analyzing a three-period model, we show that the seller may prefer to delay introducing a new product, even though the enabling technologies for the product are already available. The underlying motivation is analogous to that found in the durable goods monopolist literature – the seller suffers from a time inconsistency problem that causes his old and new products...

  1. Quad precision delay generator

    International Nuclear Information System (INIS)

    A Quad Precision Delay Generator delays a digital edge by a programmed amount of time, varying from nanoseconds to microseconds. The output of this generator has an amplitude of the order of tens of volts and rise time of the order of nanoseconds. This was specifically designed and developed to meet the stringent requirements of the plasma focus experiments. Plasma focus is a laboratory device for producing and studying nuclear fusion reactions in hot deuterium plasma. 3 figs

  2. Effect of Plant Growth Regulators on Leaf Number, Leaf Area and Leaf Dry Matter in Grape

    Directory of Open Access Journals (Sweden)

    Zahoor Ahmad BHAT

    2011-03-01

    Full Text Available Influence of phenylureas (CPPU and brassinosteriod (BR along with GA (gibberellic acid were studied on seedless grape vegetative characteristics like leaf number, leaf area and leaf dry matter. Growth regulators were sprayed on the vines either once (7 days after fruit set or 15 days after fruit set or twice (7+15 days after fruit set. CPPU 2 ppm+BR 0.4 ppm+GA 25 ppm produced maximum number of leaves (18.78 while as untreated vines produced least leaf number (16.22 per shoot. Maximum leaf area (129.70 cm2 and dry matter content (26.51% was obtained with higher CPPU (3 ppm and BR (0.4 ppm combination along with GA 25 ppm. Plant growth regulators whether naturally derived or synthetic are used to improve the productivity and quality of grapes. The relatively high value of grapes justifies more expensive inputs. A relatively small improvement in yield or fruit quality can justify the field application of a very costly product. Application of new generation growth regulators like brassinosteroids and phenylureas like CPPU have been reported to increase the leaf number as well as leaf area and dry matter thereby indirectly influencing the fruit yield and quality in grapes.

  3. 7 CFR 29.3033 - Leaf.

    Science.gov (United States)

    2010-01-01

    ... Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.3033 Section 29.3033 Agriculture Regulations... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS...

  4. 7 CFR 29.3036 - Leaf surface.

    Science.gov (United States)

    2010-01-01

    ... Leaf surface. The smoothness or roughness of the web or lamina of a tobacco leaf. Leaf surface is... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf surface. 29.3036 Section 29.3036 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS...

  5. 7 CFR 29.3525 - Leaf.

    Science.gov (United States)

    2010-01-01

    ... Type 95) § 29.3525 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.3525 Section 29.3525 Agriculture Regulations... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS...

  6. 7 CFR 29.1028 - Leaf.

    Science.gov (United States)

    2010-01-01

    ... Type 92) § 29.1028 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.1028 Section 29.1028 Agriculture Regulations... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS...

  7. Genetics of Ophraella leaf beetles

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal is to collect samples of each species of Ophraella leaf beetle encountered, not to exceed 50 specimens per species, for genetic analysis using DNA...

  8. An International Bioinformatics Infrastructure to Underpin the Arabidopsis Community

    Science.gov (United States)

    The future bioinformatics needs of the Arabidopsis community as well as those of other scientific communities that depend on Arabidopsis resources were discussed at a pair of recent meetings held by the Multinational Arabidopsis Steering Committee (MASC) and the North American Arabidopsis Steering C...

  9. Arabidopsis CDS blastp result: AK106750 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK106750 002-115-C09 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylu ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  10. Arabidopsis CDS blastp result: AK104851 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104851 001-043-A10 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylu ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  11. Arabidopsis CDS blastp result: AK100909 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100909 J023132G24 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylul ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  12. Arabidopsis CDS blastp result: AK058950 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK058950 001-020-A07 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylu ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  13. Arabidopsis CDS blastp result: AK059821 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK059821 006-205-D11 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylu ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  14. Arabidopsis CDS blastp result: AK064944 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK064944 J013000P14 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylul ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  15. Arabidopsis CDS blastp result: AK068400 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK068400 J013151M04 At3g45810.1 ferric reductase-like transmembrane component family protein sim ... ilar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ... EMBL:AF055357 [gi:3242789], similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ...

  16. Arabidopsis CDS blastp result: AK066013 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK066013 J013047I12 At3g45810.1 ferric reductase-like transmembrane component family protein sim ... ilar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ... EMBL:AF055357 [gi:3242789], similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ...

  17. Arabidopsis CDS blastp result: AK100241 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100241 J023054P13 At3g45810.1 ferric reductase-like transmembrane component family protein sim ... ilar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ... EMBL:AF055357 [gi:3242789], similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ...

  18. Arabidopsis CDS blastp result: AK318553 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK318553 J075145A22 At3g45810.1 68416.m04958 ferric reductase-like transmembrane component famil ... y protein similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ... EMBL:AF055357 [gi:3242789], similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ...

  19. Using "Arabidopsis" Genetic Sequences to Teach Bioinformatics

    Science.gov (United States)

    Zhang, Xiaorong

    2009-01-01

    This article describes a new approach to teaching bioinformatics using "Arabidopsis" genetic sequences. Several open-ended and inquiry-based laboratory exercises have been designed to help students grasp key concepts and gain practical skills in bioinformatics, using "Arabidopsis" leucine-rich repeat receptor-like kinase (LRR RLK) genetic…

  20. Agave Americana Leaf Fibers

    Directory of Open Access Journals (Sweden)

    Ashish Hulle

    2015-02-01

    Full Text Available The growing environmental problems, the problem of waste disposal and the depletion of non-renewable resources have stimulated the use of green materials compatible with the environment to reduce environmental impacts. Therefore, there is a need to design products by using natural resources. Natural fibers seem to be a good alternative since they are abundantly available and there are a number of possibilities to use all the components of a fiber-yielding crop; one such fiber-yielding plant is Agave Americana. The leaves of this plant yield fibers and all the parts of this plant can be utilized in many applications. The “zero-waste” utilization of the plant would enable its production and processing to be translated into a viable and sustainable industry. Agave Americana fibers are characterized by low density, high tenacity and high moisture absorbency in comparison with other leaf fibers. These fibers are long and biodegradable. Therefore, we can look this fiber as a sustainable resource for manufacturing and technical applications. Detailed discussion is carried out on extraction, characterization and applications of Agave Americana fiber in this paper.

  1. Why do leaf-tying caterpillars abandon their leaf ties?

    Directory of Open Access Journals (Sweden)

    Michelle Sliwinski

    2013-09-01

    Full Text Available Leaf-tying caterpillars act as ecosystem engineers by building shelters between overlapping leaves, which are inhabited by other arthropods. Leaf-tiers have been observed to leave their ties and create new shelters (and thus additional microhabitats, but the ecological factors affecting shelter fidelity are poorly known. For this study, we explored the effects of resource limitation and occupant density on shelter fidelity and assessed the consequences of shelter abandonment. We first quantified the area of leaf material required for a caterpillar to fully develop for two of the most common leaf-tiers that feed on white oak, Quercus alba. On average, Psilocorsis spp. caterpillars consumed 21.65 ± 0.67 cm2 leaf material to complete development. We also measured the area of natural leaf ties found in a Maryland forest, to determine the distribution of resources available to caterpillars in situ. Of 158 natural leaf ties examined, 47% were too small to sustain an average Psilocorsis spp. caterpillar for the entirety of its development. We also manipulated caterpillar densities within experimental ties on potted trees to determine the effects of cohabitants on the likelihood of a caterpillar to leave its tie. We placed 1, 2, or 4 caterpillars in ties of a standard size and monitored the caterpillars twice daily to track their movement. In ties with more than one occupant, caterpillars showed a significantly greater propensity to leave their tie, and left sooner and at a faster rate than those in ties as single occupants. To understand the consequences of leaf tie abandonment, we observed caterpillars searching a tree for a site to build a shelter in the field. This is a risky behavior, as 17% of the caterpillars observed died while searching for a shelter site. Caterpillars that successfully built a shelter traveled 110 ± 20 cm and took 28 ± 7 min to find a suitable site to build a shelter. In conclusion, leaf-tying caterpillars must frequently

  2. Effects of stomata clustering on leaf gas exchange.

    Science.gov (United States)

    Lehmann, Peter; Or, Dani

    2015-09-01

    A general theoretical framework for quantifying the stomatal clustering effects on leaf gaseous diffusive conductance was developed and tested. The theory accounts for stomatal spacing and interactions among 'gaseous concentration shells'. The theory was tested using the unique measurements of Dow et al. (2014) that have shown lower leaf diffusive conductance for a genotype of Arabidopsis thaliana with clustered stomata relative to uniformly distributed stomata of similar size and density. The model accounts for gaseous diffusion: through stomatal pores; via concentration shells forming at pore apertures that vary with stomata spacing and are thus altered by clustering; and across the adjacent air boundary layer. Analytical approximations were derived and validated using a numerical model for 3D diffusion equation. Stomata clustering increases the interactions among concentration shells resulting in larger diffusive resistance that may reduce fluxes by 5-15%. A similar reduction in conductance was found for clusters formed by networks of veins. The study resolves ambiguities found in the literature concerning stomata end-corrections and stomatal shape, and provides a new stomata density threshold for diffusive interactions of overlapping vapor shells. The predicted reduction in gaseous exchange due to clustering, suggests that guard cell function is impaired, limiting stomatal aperture opening. PMID:25967110

  3. Plant neighbor detection through touching leaf tips precedes phytochrome signals.

    Science.gov (United States)

    de Wit, Mieke; Kegge, Wouter; Evers, Jochem B; Vergeer-van Eijk, Marleen H; Gankema, Paulien; Voesenek, Laurentius A C J; Pierik, Ronald

    2012-09-01

    Plants in dense vegetation compete for resources, including light, and optimize their growth based on neighbor detection cues. The best studied of such behaviors is the shade-avoidance syndrome that positions leaves in optimally lit zones of a vegetation. Although proximate vegetation is known to be sensed through a reduced ratio between red and far-red light, we show here through computational modeling and manipulative experiments that leaves of the rosette species Arabidopsis thaliana first need to move upward to generate sufficient light reflection potential for subsequent occurrence and perception of a reduced red to far-red ratio. This early hyponastic leaf growth response is not induced by known neighbor detection cues under both climate chamber and natural sunlight conditions, and we identify a unique way for plants to detect future competitors through touching of leaf tips. This signal occurs before light signals and appears to be the earliest means of above-ground plant-plant signaling in horizontally growing rosette plants. PMID:22908260

  4. What determines a leaf's shape?

    Science.gov (United States)

    Dkhar, Jeremy; Pareek, Ashwani

    2014-01-01

    The independent origin and evolution of leaves as small, simple microphylls or larger, more complex megaphylls in plants has shaped and influenced the natural composition of the environment. Significant contributions have come from megaphyllous leaves, characterized usually as flat, thin lamina entrenched with photosynthetic organelles and stomata, which serve as the basis of primary productivity. During the course of evolution, the megaphylls have attained complexity not only in size or venation patterns but also in shape. This has fascinated scientists worldwide, and research has progressed tremendously in understanding the concept of leaf shape determination. Here, we review these studies and discuss the various factors that contributed towards shaping the leaf; initiated as a small bulge on the periphery of the shoot apical meristem (SAM) followed by asymmetric outgrowth, expansion and maturation until final shape is achieved. We found that the underlying factors governing these processes are inherently genetic: PIN1 and KNOX1 are indicators of leaf initiation, HD-ZIPIII, KANADI, and YABBY specify leaf outgrowth while ANGUSTIFOLIA3 and GROWTH-REGULATING FACTOR5 control leaf expansion and maturation; besides, recent research has identified new players such as APUM23, known to specify leaf polarity. In addition to genetic control, environmental factors also play an important role during the final adjustment of leaf shape. This immense amount of information available will serve as the basis for studying and understanding innovative leaf morphologies viz. the pitchers of the carnivorous plant Nepenthes which have evolved to provide additional support to the plant survival in its nutrient-deficient habitat. In hindsight, formation of the pitcher tube in Nepenthes might involve the recruitment of similar genetic mechanisms that occur during sympetaly in Petunia. PMID:25584185

  5. Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf.

    Science.gov (United States)

    Simonin, Kevin A; Burns, Emily; Choat, Brendan; Barbour, Margaret M; Dawson, Todd E; Franks, Peter J

    2015-03-01

    Leaf hydraulic conductance (k leaf) is a central element in the regulation of leaf water balance but the properties of k leaf remain uncertain. Here, the evidence for the following two models for k leaf in well-hydrated plants is evaluated: (i) k leaf is constant or (ii) k leaf increases as transpiration rate (E) increases. The difference between stem and leaf water potential (ΔΨstem-leaf), stomatal conductance (g s), k leaf, and E over a diurnal cycle for three angiosperm and gymnosperm tree species growing in a common garden, and for Helianthus annuus plants grown under sub-ambient, ambient, and elevated atmospheric CO₂ concentration were evaluated. Results show that for well-watered plants k leaf is positively dependent on E. Here, this property is termed the dynamic conductance, k leaf(E), which incorporates the inherent k leaf at zero E, which is distinguished as the static conductance, k leaf(0). Growth under different CO₂ concentrations maintained the same relationship between k leaf and E, resulting in similar k leaf(0), while operating along different regions of the curve owing to the influence of CO₂ on g s. The positive relationship between k leaf and E minimized variation in ΔΨstem-leaf. This enables leaves to minimize variation in Ψleaf and maximize g s and CO₂ assimilation rate over the diurnal course of evaporative demand. PMID:25547915

  6. Parental RNA is Significantly Degraded During Arabidopsis Seed Germination

    Institute of Scientific and Technical Information of China (English)

    Qing Li; Jian-Xun Feng; Pei Han; Yu-Xian Zhu

    2006-01-01

    Germination is the first and maybe the foremost growth stage in the life cycle of a plant. Herein, we report that initiation of germination in the Arabidopsis Columbia ecotype was accompanied by a sharp decrease in the amount of extractable total RNA. At the beginning of our germination experiment, we were usually able to obtain 35-40 μg total RNA from 100 mg dry seeds. However, after 3 d of cold stratification, we could only obtain less than 5 μg total RNA from the same amount of starting material. Young seedlings contained approximately 100 μg total RNA per 100 mg fresh tissue. Further studies showed that inhibition of de novo RNA synthesis by actinomycin D prevented the degradation of parental RNA and, in the meantime, significantly delayed the germination process. Several ribonuclease-like genes that were highly expressed in dry seeds, and especially during the cold stratification period, were discovered. We propose that these enzymes are involved in the regulation of parental RNA degradation. These results indicate that parental RNA metabolism may be an important process for Arabidopsis seed germination.

  7. STATIC ANALYSIS OF LEAF SPRING

    Directory of Open Access Journals (Sweden)

    E VENUGOPAL GOUD

    2012-08-01

    Full Text Available Leaf springs are special kind of springs used in automobile suspension systems. The advantage of leaf spring over helical spring is that the ends of the spring may be guided along a definite path as it deflects to act as a structural member in addition to energy absorbing device. The main function of leaf spring is not only tosupport vertical load but also to isolate road induced vibrations. It is subjected to millions of load cycles leading to fatigue failure. Static analysis determines the safe stress and corresponding pay load of the leaf spring and also to study the behavior of structures under practical conditions. The present work attempts to analyze the safeload of the leaf spring, which will indicate the speed at which a comfortable speed and safe drive is possible. A typical leaf spring configuration of TATA-407 light commercial vehicle is chosen for study. Finite element analysis has been carried out to determine the safe stresses and pay loads.

  8. Relating Stomatal Conductance to Leaf Functional Traits

    OpenAIRE

    Kröber, Wenzel; Plath, Isa; Heklau, Heike; Bruelheide, Helge

    2015-01-01

    Leaf functional traits are important because they reflect physiological functions, such as transpiration and carbon assimilation. In particular, morphological leaf traits have the potential to summarize plants strategies in terms of water use efficiency, growth pattern and nutrient use. The leaf economics spectrum (LES) is a recognized framework in functional plant ecology and reflects a gradient of increasing specific leaf area (SLA), leaf nitrogen, phosphorus and cation content, and decreas...

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

    OpenAIRE

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

    2016-01-01

    Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interest...

  10. Proteomic Identification of Putative MicroRNA394 Target Genes in Arabidopsis thaliana Identifies Major Latex Protein Family Members Critical for Normal Development.

    Science.gov (United States)

    Litholdo, Celso G; Parker, Benjamin L; Eamens, Andrew L; Larsen, Martin R; Cordwell, Stuart J; Waterhouse, Peter M

    2016-06-01

    Expression of the F-Box protein Leaf Curling Responsiveness (LCR) is regulated by microRNA, miR394, and alterations to this interplay in Arabidopsis thaliana produce defects in leaf polarity and shoot apical meristem organization. Although the miR394-LCR node has been documented in Arabidopsis, the identification of proteins targeted by LCR F-box itself has proven problematic. Here, a proteomic analysis of shoot apices from plants with altered LCR levels identified a member of the Latex Protein (MLP) family gene as a potential LCR F-box target. Bioinformatic and molecular analyses also suggested that other MLP family members are likely to be targets for this post-translational regulation. Direct interaction between LCR F-Box and MLP423 was validated. Additional MLP members had reduction in protein accumulation, in varying degrees, mediated by LCR F-Box. Transgenic Arabidopsis lines, in which MLP28 expression was reduced through an artificial miRNA technology, displayed severe developmental defects, including changes in leaf patterning and morphology, shoot apex defects, and eventual premature death. These phenotypic characteristics resemble those of Arabidopsis plants modified to over-express LCR Taken together, the results demonstrate that MLPs are driven to degradation by LCR, and indicate that MLP gene family is target of miR394-LCR regulatory node, representing potential targets for directly post-translational regulation mediated by LCR F-Box. In addition, MLP28 family member is associated with the LCR regulation that is critical for normal Arabidopsis development. PMID:27067051

  11. Wounding of Arabidopsis halleri leaves enhances cadmium accumulation that acts as a defense against herbivory.

    Science.gov (United States)

    Plaza, Sonia; Weber, Johann; Pajonk, Simone; Thomas, Jérôme; Talke, Ina N; Schellenberg, Maja; Pradervand, Sylvain; Burla, Bo; Geisler, Markus; Martinoia, Enrico; Krämer, Ute

    2015-06-01

    Approximately 0.2% of all angiosperms are classified as metal hyperaccumulators based on their extraordinarily high leaf metal contents, for example >1% zinc, >0.1% nickel or >0.01% cadmium (Cd) in dry biomass. So far, metal hyperaccumulation has been considered to be a taxon-wide, constitutively expressed trait, the extent of which depends solely on available metal concentrations in the soil. Here we show that in the facultative metallophyte Arabidopsis halleri, both insect herbivory and mechanical wounding of leaves trigger an increase specifically in leaf Cd accumulation. Moreover, the Cd concentrations accumulated in leaves can serve as an elemental defense against herbivory by larvae of the Brassicaceae specialist small white (Pieris rapae), thus allowing the plant to take advantage of this non-essential trace element and toxin. Metal homeostasis genes are overrepresented in the systemic transcriptional response of roots to the wounding of leaves in A. halleri, supporting that leaf Cd accumulation is preceded by systemic signaling events. A similar, but quantitatively less pronounced transcriptional response was observed in A. thaliana, suggesting that the systemically regulated modulation of metal homeostasis in response to leaf wounding also occurs in non-hyperaccumulator plants. This is the first report of an environmental stimulus influencing metal hyperaccumulation. PMID:25753945

  12. Time Delay Cosmography

    CERN Document Server

    Treu, Tommaso

    2016-01-01

    Gravitational time delays, observed in strong lens systems where the variable background source is multiply-imaged by a massive galaxy in the foreground, provide direct measurements of cosmological distance that are very complementary to other cosmographic probes. The success of the technique depends on the availability and size of a suitable sample of lensed quasars or supernovae, precise measurements of the time delays, accurate modeling of the gravitational potential of the main deflector, and our ability to characterize the distribution of mass along the line of sight to the source. We review the progress made during the last 15 years, during which the first competitive cosmological inferences with time delays were made, and look ahead to the potential of significantly larger lens samples in the near future.

  13. Genetic Variation and Divergence of Genes Involved in Leaf Adaxial-Abaxial Polarity Establishment in Brassica rapa.

    Science.gov (United States)

    Liang, Jianli; Liu, Bo; Wu, Jian; Cheng, Feng; Wang, Xiaowu

    2016-01-01

    Alterations in leaf adaxial-abaxial (ad-ab) polarity are one of the main factors that influence leaf curvature. In Chinese cabbage, leaf incurvature is an essential prerequisite to the formation of a leafy head. Identifying ad-ab patterning genes and investigating their genetic variation may facilitate elucidation of the mechanisms underlying leaf incurvature during head formation. Comparative genomic analysis of 45 leaf ad-ab patterning genes in Brassica rapa based on 26 homologs of Arabidopsis thaliana indicated that these genes underwent expansion and were retained after whole genome triplication (WGT). We also assessed the nucleotide diversity and selection footprints of these 45 genes in a collection of 94 Brassica rapa accessions that were composed of heading and non-heading morphotypes. Six of the 45 genes showed significant negative Tajima's D indices and nucleotide diversity reduction in heading accessions compared to those in non-heading accessions, indicating that they underwent purifying selection. Further testing of the BrARF3.1 gene, which was one of the selection signals from a larger collection, confirmed that purifying selection did occur. Our results provide genetic evidence that ad-ab patterning genes are involved in leaf incurvature, which is associated with formation of a leafy head, as well as promote an understanding of the genetic mechanism underlying leafy head formation in Chinese cabbage. PMID:26904064

  14. Genetic Variation and Divergence of Genes Involved in Leaf Adaxial-abaxial Polarity Establishment in Brassica rapa

    Directory of Open Access Journals (Sweden)

    Jianli eLiang

    2016-02-01

    Full Text Available Alterations in leaf adaxial–abaxial (ad-ab polarity are one of the main factors that are responsible for leaf curvature. In Chinese cabbage, to form a leafy head, leaf incurvature is an essential prerequisite. Identifying ad-ab patterning genes and investigating its genetic variations will facilitate in elucidating the mechanism underlying leaf incurvature during head formation. In the present study we conducted comparative genomic analysis of the identification of 45 leaf ad-ab patterning genes in Brassica rapa based on 26 homologs in Arabidopsis thaliana, indicating that these genes underwent expansion and were retained after whole genome triplication (WGT. We also assessed the nucleotide diversity and selection footprints of these 45 genes in a collection of 94 Brassica rapa accessions that were composed of heading and non-heading morphotypes. Six of the 45 genes showed significant negative Tajima’s D indices and nucleotide diversity reduction in heading accessions compared to that in non-heading accessions, indicating that these underwent purifying selection. Further testing of the BrARF3.1 gene, which was one of the selection signals from a larger collection, confirmed that purifying selection did occur. Our results provide genetic evidence that ad-ab patterning genes are involved in leaf incurvature that is associated in the formation of a leafy head, as well as promote an understanding of the genetic mechanism underlying leafy head formation in Chinese cabbage.

  15. Approximation of distributed delays

    CERN Document Server

    Lu, Hao; Eberard, Damien; Simon, Jean-Pierre

    2010-01-01

    We address in this paper the approximation problem of distributed delays. Such elements are convolution operators with kernel having bounded support, and appear in the control of time-delay systems. From the rich literature on this topic, we propose a general methodology to achieve such an approximation. For this, we enclose the approximation problem in the graph topology, and work with the norm defined over the convolution Banach algebra. The class of rational approximates is described, and a constructive approximation is proposed. Analysis in time and frequency domains is provided. This methodology is illustrated on the stabilization control problem, for which simulations results show the effectiveness of the proposed methodology.

  16. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne;

    2011-01-01

    -stage procedures. From the Danish Registry for Plastic Surgery of the Breast, which has prospectively registered data for women undergoing breast implantations since 1999, we identified 559 women without a history of radiation therapy undergoing 592 delayed breast reconstructions following breast cancer during the......Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two...

  17. Transcriptome analysis of intraspecific competition in Arabidopsis thaliana reveals organ-specific signatures related to nutrient acquisition and general stress response pathways.

    OpenAIRE

    Masclaux Frédéric G.; Bruessow Friederike; Schweizer Fabian; Gouhier-Darimont Caroline; Keller Laurent; Reymond Philippe

    2012-01-01

    Abstract Background Plants are sessile and therefore have to perceive and adjust to changes in their environment. The presence of neighbours leads to a competitive situation where resources and space will be limited. Complex adaptive responses to such situation are poorly understood at the molecular level. Results Using microarrays, we analysed whole-genome expression changes in Arabidopsis thaliana plants subjected to intraspecific competition. The leaf and root transcriptome was strongly al...

  18. Transcriptional responses to polycyclic aromatic hydrocarbon-induced stress in Arabidopsis thaliana reveal the involvement of hormone and defense signaling pathways

    OpenAIRE

    Colón-Carmona Adán; Alkio Merianne; Weisman David

    2010-01-01

    Abstract Background Polycyclic aromatic hydrocarbons (PAHs) are toxic, widely-distributed, environmentally persistent, and carcinogenic byproducts of carbon-based fuel combustion. Previously, plant studies have shown that PAHs induce oxidative stress, reduce growth, and cause leaf deformation as well as tissue necrosis. To understand the transcriptional changes that occur during these processes, we performed microarray experiments on Arabidopsis thaliana L. under phenanthrene treatment, and c...

  19. Asynchronous Bounded Expected Delay Networks

    OpenAIRE

    Bakhshi, Rena; Endrullis, Jörg; Fokkink, Wan; Pang, Jun

    2010-01-01

    The commonly used asynchronous bounded delay (ABD) network models assume a fixed bound on message delay. We propose a probabilistic network model, called asynchronous bounded expected delay (ABE) model. Instead of a strict bound, the ABE model requires only a bound on the expected message delay. While the conditions of ABD networks restrict the set of possible executions, in ABE networks all asynchronous executions are possible, but executions with extremely long delays are less probable. In ...

  20. Requirement of KNAT1/BP for the Development of Abscission Zones in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Xiao-Qun Wang; Wei-Hui Xu; Li-Geng Ma; Zhi-Ming Fu; Xing-Wang Deng; Jia-Yang Li; Yong-Hong Wang

    2006-01-01

    The KNAT1 gene is a member of the Class Ⅰ KNOXhomeobox gene family and is thought to play an important role in meristem development and leaf morphogenesis. Recent studies have demonstrated that KNAT1/BP regulates the architecture of the inflorescence by affecting pedicle development in Arabidopsis thaliana.Herein, we report the characterization of an Arabidopsis T-DNA insertion mutant that shares considerable phenotypic similarity to the previously identified mutant brevipedicle (bp). Molecular and genetic analyses showed that the mutant is allelic to bp and that the T-DNA is located within the first helix of the KNAT1homeodomain (HD). Although the mutation causes a typical abnormality of short pedicles, propendent siliques,and semidwarfism, no obvious defects are observed in the vegetative stage. A study on cell morphology showed that asymmetrical division and inhibition of cell elongation contribute to the downward-pointing and shorter pedicle phenotype. Loss of KNAT/BPfunction results in the abnormal development of abscission zones. Microarray analysis of gene expression profiling suggests that KNAT1/BP may regulate abscission zone development through hormone signaling and hormone metabolism in Arabidopsis.

  1. Comparative proteomics and physiological characterization of Arabidopsis thaliana seedlings in responses to Ochratoxin A.

    Science.gov (United States)

    Wang, Yan; Hao, Junran; Zhao, Weiwei; Yang, Zhuojun; Wu, Weihong; Zhang, Yu; Xu, Wentao; Luo, YunBo; Huang, Kunlun

    2013-07-01

    Ochratoxin A (OTA) is a mycotoxin that is primarily produced by Aspergillus ochraceus and Penicillium verrucosum. This mycotoxin is a contaminant of food and feedstock worldwide and may induce cell death in plants. To investigate the dynamic growth process of Arabidopsis seedlings in response to OTA stress and to obtain a better understanding of the mechanism of OTA toxicity towards Arabidopsis, a comparative proteomics study using 2-DE and MALDI-TOF/TOF MS/MS was performed. Mass spectrometry analysis identified 59 and 51 differentially expressed proteins in seedlings exposed to 25 and 45 μM OTA for 7 days, respectively. OTA treatment decreased root elongation and leaf area, increased anthocyanin accumulation, damaged the photosynthetic apparatus and inhibited photosynthesis. Treatment of the seedlings with 25 μM OTA enhanced energy metabolism, whereas higher concentration of OTA (45 μM) inhibited energy metabolism in the seedlings. OTA treatment caused an increase of ROS, an enhancement of antioxidant enzyme defense responses, disturbance of redox homeostasis and activation of lipid oxidation. Glutamine and S-adenosylmethionine metabolism may also play important roles in the response to OTA. In conclusion, our study provided novel insights regarding the response of Arabidopsis to OTA at the level of the proteome. These results are expected to be highly useful for understanding the physiological responses and dissecting the OTA response pathways in higher plants. PMID:23625346

  2. Functional Analysis of the Arabidopsis TETRASPANIN Gene Family in Plant Growth and Development.

    Science.gov (United States)

    Wang, Feng; Muto, Antonella; Van de Velde, Jan; Neyt, Pia; Himanen, Kristiina; Vandepoele, Klaas; Van Lijsebettens, Mieke

    2015-11-01

    TETRASPANIN (TET) genes encode conserved integral membrane proteins that are known in animals to function in cellular communication during gamete fusion, immunity reaction, and pathogen recognition. In plants, functional information is limited to one of the 17 members of the Arabidopsis (Arabidopsis thaliana) TET gene family and to expression data in reproductive stages. Here, the promoter activity of all 17 Arabidopsis TET genes was investigated by pAtTET::NUCLEAR LOCALIZATION SIGNAL-GREEN FLUORESCENT PROTEIN/β-GLUCURONIDASE reporter lines throughout the life cycle, which predicted functional divergence in the paralogous genes per clade. However, partial overlap was observed for many TET genes across the clades, correlating with few phenotypes in single mutants and, therefore, requiring double mutant combinations for functional investigation. Mutational analysis showed a role for TET13 in primary root growth and lateral root development and redundant roles for TET5 and TET6 in leaf and root growth through negative regulation of cell proliferation. Strikingly, a number of TET genes were expressed in embryonic and seedling progenitor cells and remained expressed until the differentiation state in the mature plant, suggesting a dynamic function over developmental stages. The cis-regulatory elements together with transcription factor-binding data provided molecular insight into the sites, conditions, and perturbations that affect TET gene expression and positioned the TET genes in different molecular pathways; the data represent a hypothesis-generating resource for further functional analyses. PMID:26417009

  3. Fluorescence reports intact quantum dot uptake into roots and translocation to leaves of Arabidopsis thaliana and subsequent ingestion by insect herbivores.

    Science.gov (United States)

    Koo, Yeonjong; Wang, Jing; Zhang, Qingbo; Zhu, Huiguang; Chehab, E Wassim; Colvin, Vicki L; Alvarez, Pedro J J; Braam, Janet

    2015-01-01

    We explored the impact of quantum dot (QD) coat characteristics on NP stability, uptake, and translocation in Arabidopsis thaliana, and subsequent transfer to primary consumers, Trichoplusia ni (T. ni). Arabidopsis was exposed to CdSe/CdZnS QDs with three different coatings: Poly(acrylic acid-ethylene glycol) (PAA-EG), polyethylenimine (PEI) and poly(maleic anhydride-alt-1-octadecene)-poly(ethylene glycol) (PMAO-PEG), which are anionic, cationic, and relatively neutral, respectively. PAA-EG-coated QDs were relatively stable and taken up from a hydroponic medium through both Arabidopsis leaf petioles and roots, without apparent aggregation, and showed generally uniform distribution in leaves. In contrast, PEI- and PMAO-PEG-coated QDs displayed destabilization in the hydroponic medium, and generated particulate fluorescence plant tissues, suggesting aggregation. PAA-EG QDs moved faster than PEI QDs through leaf petioles; however, 8-fold more cadmium accumulated in PEI QD-treated leaves than in those exposed to PAA-EG QDs, possibly due to PEI QD dissolution and direct metal uptake. T. ni caterpillars that fed on Arabidopsis exposed to QDs had reduced performance, and QD fluorescence was detected in both T. ni bodies and frass, demonstrating trophic transfer of intact QDs from plants to insects. Overall, this paper demonstrates that QD coat properties influence plant nanoparticle uptake and translocation and can impact transfer to herbivores. PMID:25437125

  4. Functional relationships of leafing intensity to plant height, growth form and leaf habit

    Science.gov (United States)

    Yan, En-Rong; Milla, Rubén; Aarssen, Lonnie W.; Wang, Xi-Hua

    2012-05-01

    Leafing intensity, i.e. the number of leaves per unit of stem volume or mass, is a common developmental correlate of leaf size. However, the ecological significance and the functional implications of variation in leafing intensity, other than its relation to leaf size, are unknown. Here, we explore its relationships with plant height, growth form, leaf size, and leaf habit to test a series of corollaries derived from the leafing intensity premium hypothesis. Volume-based leafing intensities and plant heights were recorded for 109 woody species from the subtropical evergreen broadleaf forests of eastern China. In addition, we compiled leafing intensity data from published literature, and combined it with our data to form a 398 species dataset, to test for differences of leafing intensity between plant growth forms (i.e. herbaceous and woody) and leaf habits (i.e. deciduous and evergreens). Leafing intensity was negatively correlated with plant height and individual leaf mass. Volume-based leafing intensities were significantly higher in herbaceous species than in woody species, and also higher in deciduous than in evergreen woody species. In conclusion, leafing intensity relates strongly to plant height, growth form, leaf size, and leaf habit in directions generally in accordance to the leafing intensity premium hypothesis. These results can be interpreted in terms of the evolution of adaptive strategies involving response to herbivory, competitive ability for light and reproductive economy.

  5. Expression of NO scavenging hemoglobin is involved in the timing of bolting in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Hebelstrup, Kim Henrik; Jensen, Erik Østergaard

    2008-01-01

    -symbiotic hemoglobin gene, GLB2, in Arabidopsis thaliana. Lines with GLB1 silencing had a significant delay of bolting and after bolting, shoots reverted to the rosette vegetative phase by formation of aerial rosettes at lateral meristems. Lines with overexpression of GLB1 or GLB2 bolted earlier than wild type plants....... By germinating the lines in a medium containing the nitric oxide (NO) donor, sodium nitroprusside (SNP), it was demonstrated that both GLB1 and GLB2 promote bolting by antagonizing the effect of NO, suggesting that non-symbiotic plant hemoglobin controls bolting by scavenging the floral transition...... with an optimum at low concentrations. It was observed that overexpression of either GLB1 or GLB2 shifts the optimum for NO growth stimulation to a higher concentration. In conclusion, we have found that expression of NO scavenging plant hemoglobin is involved in the control of bolting in Arabidopsis....

  6. The Arabidopsis thaliana homeobox gene ATHB12 is involved in symptom development caused by geminivirus infection.

    Directory of Open Access Journals (Sweden)

    Jungan Park

    Full Text Available BACKGROUND: Geminiviruses are single-stranded DNA viruses that infect a number of monocotyledonous and dicotyledonous plants. Arabidopsis is susceptible to infection with the Curtovirus, Beet severe curly top virus (BSCTV. Infection of Arabidopsis with BSCTV causes severe symptoms characterized by stunting, leaf curling, and the development of abnormal inflorescence and root structures. BSCTV-induced symptom development requires the virus-encoded C4 protein which is thought to interact with specific plant-host proteins and disrupt signaling pathways important for controlling cell division and development. Very little is known about the specific plant regulatory factors that participate in BSCTV-induced symptom development. This study was conducted to identify specific transcription factors that are induced by BSCTV infection. METHODOLOGY/PRINCIPAL FINDINGS: Arabidopsis plants were inoculated with BSCTV and the induction of specific transcription factors was monitored using quantitative real-time polymerase chain reaction assays. We found that the ATHB12 and ATHB7 genes, members of the homeodomain-leucine zipper family of transcription factors previously shown to be induced by abscisic acid and water stress, are induced in symptomatic tissues of Arabidopsis inoculated with BSCTV. ATHB12 expression is correlated with an array of morphological abnormalities including leaf curling, stunting, and callus-like structures in infected Arabidopsis. Inoculation of plants with a BSCTV mutant with a defective c4 gene failed to induce ATHB12. Transgenic plants expressing the BSCTV C4 gene exhibited increased ATHB12 expression whereas BSCTV-infected ATHB12 knock-down plants developed milder symptoms and had lower ATHB12 expression compared to the wild-type plants. Reporter gene studies demonstrated that the ATHB12 promoter was responsive to BSCTV infection and the highest expression levels were observed in symptomatic tissues where cell cycle genes also were

  7. How to pattern a leaf.

    Science.gov (United States)

    Bolduc, N; O'Connor, D; Moon, J; Lewis, M; Hake, S

    2012-01-01

    Leaf development presents a tremendous resource for tackling the question of patterning in biology. Leaves can be simple or highly dissected. They may have elaborated parts such as the tendrils of a pea leaf or the rolled blade of a carnivorous pitcher plant. Despite the variation in size, shape, and function, all leaves initiate in the same manner: from the flanks of a meristem. The maize leaf is useful for analysis of patterning due to the wealth of mutants and the distinct tissues along the proximal distal axis. The blade is distal, the sheath is proximal, and the ligule forms at the blade/sheath boundary. Establishment of this boundary involves the transcription factors LIGULELESS1 and LIGULELESS2 and the kinase LIGULELESS NARROW. The meristem-specific protein KNOTTED1 (KN1) binds and modulates the lg2 gene. Given the localization of KN1 at the proximal end of the leaf from the time of inception, we hypothesize that KN1 has a role in establishing the very proximal end of the leaf, whereas an auxin maximum guides the growing distal tip. PMID:23174765

  8. Delayed traumatic diaphragmatic hernia

    Science.gov (United States)

    Lu, Jing; Wang, Bo; Che, Xiangming; Li, Xuqi; Qiu, Guanglin; He, Shicai; Fan, Lin

    2016-01-01

    Abstract Background: Traumatic diaphragmatic hernias (TDHs) are sometimes difficult to identify at an early stage and can consequently result in diagnostic delays with life-threatening outcomes. It is the aim of this case study to highlight the difficulties encountered with the earlier detection of traumatic diaphragmatic hernias. Methods: Clinical data of patients who received treatment for delayed traumatic diaphragmatic hernias in registers of the First Affiliated Hospital of Xi’an Jiaotong University from 1998 to 2014 were analyzed retrospectively. Results: Six patients were included in this study. Left hemidiaphragm was affected in all of them. Most of the patients had a history of traffic accident and 1 a stab-penetrating injury. The interval from injury to developing symptoms ranged from 2 to 11 years (median 5 years). The hernial contents included the stomach, omentum, small intestine, and colon. Diaphragmatic injury was missed in all of them during the initial managements. All patients received operations once the diagnosis of delayed TDH was confirmed, and no postoperative mortality was detected. Conclusions: Delayed TDHs are not common, but can lead to serious consequences once occurred. Early detection of diaphragmatic injuries is crucial. Surgeons should maintain a high suspicion for injuries of the diaphragm in cases with abdominal or lower chest traumas, especially in the initial surgical explorations. We emphasize the need for radiographical follow-up to detect diaphragmatic injuries at an earlier stage. PMID:27512848

  9. Speech and Language Delay

    Science.gov (United States)

    ... child depends on the cause of the speech delay. Your doctor will tell you the cause of your child's problem and explain any treatments that might fix the problem or make it better. A speech and language pathologist might be helpful in making treatment plans. This ...

  10. Transcription Factor ATAF1 in Arabidopsis Promotes Senescence by Direct Regulation of Key Chloroplast Maintenance and Senescence Transcriptional Cascades.

    Science.gov (United States)

    Garapati, Prashanth; Xue, Gang-Ping; Munné-Bosch, Sergi; Balazadeh, Salma

    2015-07-01

    Senescence represents a fundamental process of late leaf development. Transcription factors (TFs) play an important role for expression reprogramming during senescence; however, the gene regulatory networks through which they exert their functions, and their physiological integration, are still largely unknown. Here, we identify the Arabidopsis (Arabidopsis thaliana) abscisic acid (ABA)- and hydrogen peroxide-activated TF Arabidopsis thaliana activating factor1 (ATAF1) as a novel upstream regulator of senescence. ATAF1 executes its physiological role by affecting both key chloroplast maintenance and senescence-promoting TFs, namely GOLDEN2-LIKE1 (GLK1) and ORESARA1 (Arabidopsis NAC092), respectively. Notably, while ATAF1 activates ORESARA1, it represses GLK1 expression by directly binding to their promoters, thereby generating a transcriptional output that shifts the physiological balance toward the progression of senescence. We furthermore demonstrate a key role of ATAF1 for ABA- and hydrogen peroxide-induced senescence, in accordance with a direct regulatory effect on ABA homeostasis genes, including nine-CIS-epoxycarotenoid dioxygenase3 involved in ABA biosynthesis and ABC transporter G family member40, encoding an ABA transport protein. Thus, ATAF1 serves as a core transcriptional activator of senescence by coupling stress-related signaling with photosynthesis- and senescence-related transcriptional cascades. PMID:25953103

  11. High throughput selection of novel plant growth regulators: Assessing the translatability of small bioactive molecules from Arabidopsis to crops.

    Science.gov (United States)

    Rodriguez-Furlán, Cecilia; Miranda, Giovanna; Reggiardo, Martín; Hicks, Glenn R; Norambuena, Lorena

    2016-04-01

    Plant growth regulators (PGRs) have become an integral part of agricultural and horticultural practices. Accordingly, there is an increased demand for new and cost-effective products. Nevertheless, the market is limited by insufficient innovation. In this context chemical genomics has gained increasing attention as a powerful approach addressing specific traits. Here is described the successful implementation of a highly specific, sensitive and efficient high throughput screening approach using Arabidopsis as a model. Using a combination of techniques, 10,000 diverse compounds were screened and evaluated for several important plant growth traits including root and leaf growth. The phenotype-based selection allowed the compilation of a collection of putative Arabidopsis growth regulators with a broad range of activities and specificities. A subset was selected for evaluating their bioactivity in agronomically valuable plants. Their validation as growth regulators in commercial species such as tomato, lettuce, carrot, maize and turfgrasses reinforced the success of the screening in Arabidopsis and indicated that small molecules activity can be efficiently translated to commercial species. Therefore, the chemical genomics approach in Arabidopsis is a promising field that can be incorporated in PGR discovery programs and has a great potential to develop new products that can be efficiently used in crops. PMID:26940491

  12. Interferometric Propagation Delay

    Science.gov (United States)

    Goldstein, Richard

    1999-01-01

    Radar interferometry based on (near) exact repeat passes has lately been used by many groups of scientists, worldwide, to achieve state of the art measurements of topography, glacier and ice stream motion, earthquake displacements, oil field subsidence, lava flows, crop-induced surface decorrelation, and other effects. Variations of tropospheric and ionospheric propagation delays limit the accuracy of all such measurements. We are investigating the extent of this limitation, using data from the Shuttle radar flight, SIR-C, which is sensitive to the troposphere, and the Earth Resources Satellites, ERS-1/2, which are sensitive to both the troposphere and the ionosphere. We are presently gathering statistics of the delay variations over selected, diverse areas to determine the best accuracy possible for repeat track interferometry. The phases of an interferogram depend on both the topography of the scene and variations in propagation delay. The delay variations can be caused by movement of elements in the scene, by changes in tropospheric water vapor and by changes of the charge concentrations in the ionosphere. We plan to separate these causes by using the data from a third satellite visit (three-pass interferometry). The figure gives the geometry of the three-pass observations. The page of the figure is taken to be perpendicular to the spacecraft orbits. The three observational locations are marked on the figure, giving baselines B-12 and B-13, separated by the angle alpha. These parameters are almost constant over the whole scene. However, each pixel has an individual look angle, theta, which is related to the topography, rho is the slant range. A possible spurious time delay is shown. Additional information is contained in the original.

  13. Optimizing environmental conditions for mass application of mechano-dwarfing stimuli to Arabidopsis

    Science.gov (United States)

    Montgomery, Jill A.; Bressan, Ray A.; Mitchell, Cary A.

    2004-01-01

    Obtaining uniform mechano-dwarfing of Arabidopsis thaliana (L.) Heynh. seedlings within dense plantings is problematic. Alternative forms of mechano-stimulation were applied to seedlings in effort to obtain uniform growth reduction compared with undisturbed controls in both greenhouse and controlled growth environments. Arabidopsis grown under low photosynthetic photon flux (PPF) artificial light grew upright with limited leaf expansion, which enhanced mechano-responsiveness compared to that of rosette-growing plants under filtered sunlight or high PPF artificial light. Hypocotyls of seedlings grown at PPFs > 60 micromoles m-2 s-1 elongated less and had 6% less sensitivity to mechanical stress than seedlings grown at PPFs < 60 micromoles m-2 s-1. Fluorescent lamps alone (F) or fluorescent plus incandescent (F+I) lamps were compared for seedling responses to mechanical stress. Under F lighting, hypocotyl elongation was reduced 25% to 40% by twice-daily brush or plate treatments, and brushed seedlings exhibited more growth reduction than did plate treatments. Seedlings grown under F+I lamps exhibited similar stress-induced growth reduction compared to seedlings grown under F only, but stressed F+I seedlings lodged to a greater extent due to excessive hypocotyl elongation. Temperature-response studies using standardized F-only lighting indicated increased hypocotyl elongation but decreased leaf expansion, and decreased mechano-responsivity to brushing over the temperature range from 20 to 28 degrees C. Daylength studies indicated similar degrees of mechano-inhibition of hypocotyl elongation over the daylength range of 12, 16, 20, and 24 hours, whereas fresh weight of stressed seedling shoots declined compared to controls. A combination of environmental growth parameters that give repeatable, visual mechanical dwarfing of Arabidopsis include low-PPF fluorescent lighting from 55 to 60 micromoles m-2 s-1, ambient temperatures from 22 to 25 degrees C, and twice

  14. Zinc distribution and speciation in Arabidopsis halleri x Arabidops is lyrata progenies presenting various zinc accumulation capacities

    Energy Technology Data Exchange (ETDEWEB)

    Sarret, Geraldine; Willems, Glenda; Isaure, Marie-Pierre; Marcus, Matthew A.; Fakra, Sirine C.; Frerot, Helene; Pairis, Sebastien; Geoffroy, Nicolas; Manceau, Alain; Saumitou-Laprade, Pierre

    2010-04-08

    - The purpose of this study was to investigate the relationship between the chemical form and localization of zinc (Zn) in plant leaves and their Zn accumulationcapacity. - An interspecific cross between Arabidopsis halleri sp. halleri and Arabidopsis lyrata sp. petrea segregating for Zn accumulation was used. Zinc (Zn) speciation and Zn distribution in the leaves of the parent plants and of selected F1 and F2 progenies were investigated by spectroscopic and microscopic techniques and chemical analyses. - A correlation was observed between the proportion of Zn being in octahedral coordination complexed to organic acids and free in solution (Zn?OAs + Znaq) and Zn content in the leaves. This pool varied between 40percent and 80percent of total leaf Zn depending on the plant studied. Elemental mapping of the leaves revealed different Zn partitioning between the veins and the leaf tissue. The vein : tissue fluorescence ratio was negatively correlated with Zn accumulation. - The higher proportion of Zn?OAs + Znaq and the depletion of the veins in the stronger accumulators are attributed to a higher xylem unloading and vacuolar sequestration in the leaf cells. Elemental distributions in the trichomes were also investigated, and results support the role of carboxyl and⁄ or hydroxyl groups as major Zn ligands in these cells.

  15. Analysis of Peanut Leaf Proteome

    DEFF Research Database (Denmark)

    Ramesh, R.; Suravajhala, Prashanth; Pechan, T.

    2010-01-01

    approach to define function of their associated genes. Proteome analysis linked to genome sequence information is critical for functional genomics. However, the available protein expression data is extremely inadequate. Proteome analysis of peanut leaf was conducted using two-dimensional gel....... Furthermore, the leaf proteome map will lead to development of protein markers for cultivar identification at seedling stage of the plant. Overall, this study will contribute to improve our understanding of plant genetics and metabolism, and overall assist in the selection and breeding programs geared toward...

  16. Biophysical control of leaf temperature

    Science.gov (United States)

    Dong, N.; Prentice, I. C.; Wright, I. J.

    2014-12-01

    In principle sunlit leaves can maintain their temperatures within a narrower range than ambient temperatures. This is an important and long-known (but now overlooked) prediction of energy balance theory. Net radiation at leaf surface in steady state (which is reached rapidly) must be equal to the combination of sensible and latent heat exchanges with surrounding air, the former being proportional to leaf-to-air temperature difference (ΔT), the latter to the transpiration rate. We present field measurements of ΔT which confirm the existence of a 'crossover temperature' in the 25-30˚C range for species in a tropical savanna and a tropical rainforest environment. This finding is consistent with a simple representation of transpiration as a function of net radiation and temperature (Priestley-Taylor relationship) assuming an entrainment factor (ω) somewhat greater than the canonical value of 0.26. The fact that leaves in tropical forests are typically cooler than surrounding air, often already by solar noon, is consistent with a recently published comparison of MODIS day-time land-surface temperatures with air temperatures. Theory further predicts a strong dependence of leaf size (which is inversely related to leaf boundary-layer conductance, and therefore to absolute magnitude of ΔT) on moisture availability. Theoretically, leaf size should be determined by either night-time constraints (risk of frost damage to active leaves) or day-time constraints (risk of heat stress damage),with the former likely to predominate - thereby restricting the occurrence of large leaves - at high latitudes. In low latitudes, daytime maximum leaf size is predicted to increase with temperature, provided that water is plentiful. If water is restricted, however, transpiration cannot proceed at the Priestley-Taylor rate, and it quickly becomes advantageous for plants to have small leaves, which do not heat up much above the temperature of their surroundings. The difference between leaf

  17. RELATIONSHIP BETWEEN MANGOSTEEN LEAF NITROGEN CONTENTS AND LEAF SPAD VALUES

    Directory of Open Access Journals (Sweden)

    Eko Setiawan

    2014-03-01

    Full Text Available We investigated nitrogen contents on mangosteen leaf and related on leaf SPAD value. The experiment was conducted using mangosteen trees grown in commercial orchard in Bogor, Indonesia during May to October 2010. Mangosteen trees of 3 different ages, young (20-year-old, middle-aged (35-year-old, and old (50-year-old trees, each of five trees, were selected for study, and the canopy of each tree was divided into 9 sectors based on height (bottom, middle, top and width (inner, center, outer. SPAD values had a negative correlation with leaf N content in all ages and could be explained by regressionl equations N level (% DW = -0.0099 × SPAD + 2.2366; R² = 0.91; N level (% DW = -0.0177 × SPAD + 2.8001; R² = 0.67; and N level (% DW = -0.0187 × SPAD + 2.7785; R² = 0.45 in young, middle-aged and old trees, respectively. It is suggested that the SPAD value determined by a portable chlorophyll meter can be used to obtain a quick estimation of mangosteen leaf N status. Keywords: age, fruiting position, Garcinia mangostana L., nitrogen, SPAD

  18. A leaf detection method using image sequences and leaf movement

    NARCIS (Netherlands)

    Hemming, J.; Henten, van E.J.; Tuijl, van B.A.J.; Bontsema, J.

    2005-01-01

    Besides harvesting the fruits, a very time demanding task is removing old leaves from cucumber and tomato plants grown in greenhouses. To be able to automate this process by a robot, a leaf detection method is required. One possibility for the detection is to exploit the different dynamic behaviour

  19. Transformation of Arabidopsis thaliana via Agrobacterium tumefacience with an endochitinase gene from Trichoderma, and enhanced resistance to Sclerotinia sclerotiorum

    Institute of Scientific and Technical Information of China (English)

    DAI Fu-ming; XU Tong

    2004-01-01

    @@ Sclerotinia sclerotiorum is an important pathogen to many crops and is especially damaging to rape in China. As a model plant Arabidopsis thaliana (ColO) was transformed by spraying Agrobacterium tumefacience with Trichoderma endochitinase gene ThEn-42 at initial bud stage. Eleven seedlings (corresponding to about 0.22 percent transformation) exhibited resistance to hygromycin. The DNA fragment unique to endochitinase ( ThEn-42 ) was amplified by Arabidopsis leaf-PCR or genomic DNA PCR. Unfertile, dwarf and normal phenotypes appeared in the T1 generation. In addition, an enhanced resistance to S. sclerotiorum was observed. The mortality percentage (7.7% to 33.3%) in transgenic plants was significantly lower than in non-transgenic plants (86. 7%) 10 days after inoculation with the pathogen.

  20. Ectopic expression of Arabidopsis ABC transporter MRP7 modifies cadmium root-to-shoot transport and accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Wojas, Sylwia [Faculty of Biology, University of Warsaw, Miecznikowa str. 1, 02-096 Warszawa (Poland); Hennig, Jacek [Institute of Biochemistry and Biophysics PAS, Pawinskiego str. 5A, 02-106 Warszawa (Poland); Plaza, Sonia; Geisler, Markus [Institute of Plant Biology, University of Zuerich, CH-8008 Zuerich (Switzerland); Siemianowski, Oskar; Sklodowska, Aleksandra [Faculty of Biology, University of Warsaw, Miecznikowa str. 1, 02-096 Warszawa (Poland); Ruszczynska, Anna; Bulska, Ewa [Faculty of Chemistry, University of Warsaw, Pasteura str.1, 02-093 Warszawa (Poland); Antosiewicz, Danuta M., E-mail: dma@biol.uw.edu.p [Faculty of Biology, University of Warsaw, Miecznikowa str. 1, 02-096 Warszawa (Poland)

    2009-10-15

    Arabidopsis MRPs/ABCCs have been shown to remove various organic and inorganic substrates from the cytosol to other subcellular compartments. Here we first demonstrate that heterologous expression of AtMRP7 in tobacco (Nicotiana tabacum var. Xanthi) modifies cadmium accumulation, distribution and tolerance. Arabidopsis MRP7 was localized both in the tonoplast and in the plasma membrane when expressed in tobacco. Its overexpression increased tobacco Cd-tolerance and resulted in enhanced cadmium concentration in leaf vacuoles, indicating more efficient detoxification by means of vacuolar storage. Heterologous AtMRP7 expression also led to more efficient retention of Cd in roots, suggesting a contribution to the control of cadmium root-to-shoot translocation. The results underscore the use of AtMRP7 in plant genetic engineering to modify the heavy-metal accumulation pattern for a broad range of applications. - AtMRP7 expression in tobacco enhances Cd-tolerance and increases Cd storage in vacuoles

  1. Arabidopsis CDS blastp result: AK119708 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK119708 002-157-E08 At1g28330.1 dormancy-associated protein, putative (DRM1) identical to dormancy...-associated protein [Arabidopsis thaliana] GI:2995990; similar to dormancy-associated protei

  2. Arabidopsis CDS blastp result: AK060981 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060981 006-202-H08 At1g28330.1 dormancy-associated protein, putative (DRM1) identical to dormancy...-associated protein [Arabidopsis thaliana] GI:2995990; similar to dormancy-associated protei

  3. Arabidopsis CDS blastp result: AK111736 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111736 J023047L09 At1g68370.1 gravity -responsive protein / altered response to gravity ... protein ... (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  4. Arabidopsis CDS blastp result: AK070093 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK070093 J023041M10 At2g39290.1 phosphatidylglycerolphosphate synthase (PGS1) identical to phosphati...dylglycerolphosphate synthase GI:13365519 from [Arabidopsis thaliana] 7e-78 ...

  5. Arabidopsis CDS blastp result: AK060009 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060009 006-302-D03 At2g39290.1 phosphatidylglycerolphosphate synthase (PGS1) identical to phosphati...dylglycerolphosphate synthase GI:13365519 from [Arabidopsis thaliana] 8e-71 ...

  6. Arabidopsis CDS blastp result: AK058419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK058419 001-015-D06 At4g16280.3 flowering time ... control protein / FCA gamma (FCA) identical to S ... P|O04425 Flowering time ... control protein FCA {Arabidopsis thaliana}; four a ...

  7. Arabidopsis CDS blastp result: AK073225 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK073225 J033023C04 At4g16280.3 flowering time ... control protein / FCA gamma (FCA) identical to SP ... |O04425 Flowering time ... control protein FCA {Arabidopsis thaliana}; four a ...

  8. Arabidopsis CDS blastp result: AK102695 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK102695 J033103F21 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  9. Arabidopsis CDS blastp result: AK102134 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK102134 J033085F12 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  10. Arabidopsis CDS blastp result: AK066835 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK066835 J013087I16 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-171 ...

  11. Arabidopsis CDS blastp result: AK065259 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK065259 J013002J18 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  12. Arabidopsis CDS blastp result: AK100523 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100523 J023100P04 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  13. Arabidopsis CDS blastp result: AK288065 [KOME

    Lifescience Database Archive (English)

    Full Text Available al to sulfate tansporter Sultr1;3 [Arabidopsis thaliana] GI:10716805; contains Pfam profile PF00916: Sulfate... transporter family; contains Pfam profile PF01740: STAS domain; contains TIGRfam profile TIGR00815: sulfate permease 1e-145 ...

  14. Arabidopsis CDS blastp result: AK288002 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288002 J075110B01 At1g68510.1 68414.m07826 LOB domain protein 42 ... / lateral organ boundaries do ... main protein 42 ... (LBD42 ) identical to LOB DOMAIN 42 ... [Arabidopsis th ...

  15. Arabidopsis CDS blastp result: AK241043 [KOME

    Lifescience Database Archive (English)

    Full Text Available upted by a stop codon, creating non-consensus donor and acceptor splice sites. 2e-41 ... ...tical to SP|P92997 Germin-like protein subfamily 1 member 13 precursor {Arabidopsis thaliana}; exon 2 interr

  16. Arabidopsis CDS blastp result: AK243135 [KOME

    Lifescience Database Archive (English)

    Full Text Available upted by a stop codon, creating non-consensus donor and acceptor splice sites. 7e-43 ... ...tical to SP|P92997 Germin-like protein subfamily 1 member 13 precursor {Arabidopsis thaliana}; exon 2 interr

  17. Arabidopsis CDS blastp result: AK111785 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111785 J023089N11 At5g62310.1 incomplete root hair ... elongation (IRE) / protein kinase, putative ... nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  18. Arabidopsis CDS blastp result: AK243050 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243050 J100011E04 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  19. Arabidopsis CDS blastp result: AK242758 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242758 J090051H03 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  20. Arabidopsis CDS blastp result: AK242717 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242717 J090043H19 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  1. Arabidopsis CDS blastp result: AK288095 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288095 J075191E21 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  2. Arabidopsis CDS blastp result: AK242638 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242638 J090023J02 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  3. Arabidopsis CDS blastp result: AK242651 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242651 J090026B08 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  4. Arabidopsis CDS blastp result: AK287631 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287631 J065073J24 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  5. Arabidopsis CDS blastp result: AK288923 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288923 J090081P06 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  6. Arabidopsis CDS blastp result: AK242271 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242271 J075187A19 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  7. Arabidopsis CDS blastp result: AK242681 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242681 J090032N04 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  8. Arabidopsis CDS blastp result: AK243656 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243656 J100088L22 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  9. Arabidopsis CDS blastp result: AK241519 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241519 J065170E12 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  10. Arabidopsis CDS blastp result: AK240655 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240655 J023135E11 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  11. Arabidopsis CDS blastp result: AK242733 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242733 J090047O22 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  12. Arabidopsis CDS blastp result: AK242859 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242859 J090073L24 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  13. Arabidopsis CDS blastp result: AK243187 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243187 J100039E11 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  14. Arabidopsis CDS blastp result: AK242550 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242550 J080319D10 At2g35630.1 68415.m04369 microtubule organization 1 protein (MO...R1) identical to microtubule organization 1 protein GI:14317953 from [Arabidopsis thaliana] 5e-44 ...

  15. Arabidopsis CDS blastp result: AK101368 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK101368 J033035L13 At5g24270.1 calcineurin B-like protein, putative / calcium sensor ... homolog (S ... OS3) identical to calcium sensor ... homolog [Arabidopsis thaliana] GI:3309575; similar ...

  16. Arabidopsis CDS blastp result: AK111570 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111570 J013071C24 At5g24270.1 calcineurin B-like protein, putative / calcium sensor ... homolog (S ... OS3) identical to calcium sensor ... homolog [Arabidopsis thaliana] GI:3309575; similar ...

  17. Arabidopsis CDS blastp result: AK243065 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243065 J100015N03 At5g24270.1 68418.m02855 calcineurin B-like protein, putative / calcium sensor ... or homolog (SOS3) identical to calcium sensor ... homolog [Arabidopsis thaliana] GI:3309575; similar ...

  18. The fifth international conference on Arabidopsis research

    Energy Technology Data Exchange (ETDEWEB)

    Hangarter, R.; Scholl, R.; Davis, K.; Feldmann, K.

    1993-12-31

    This volume contains abstracts of oral and poster presentations made in conjunction with the Fifth International Conference on Arabidopsis Research held August 19--22, 1993 at the Ohio State University, Columbus, Ohio.

  19. Arabidopsis CDS blastp result: AK070528 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK070528 J023060D13 At3g10920.1 superoxide dismutase [Mn], mitochondrial (SODA) / manganese ... supe ... roxide dismutase (MSD1) identical to manganese ... superoxide dismutase [Arabidopsis thaliana] gi|327 ...

  20. Arabidopsis CDS blastp result: AK119904 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK119904 002-182-A05 At3g10920.1 superoxide dismutase [Mn], mitochondrial (SODA) / manganese ... sup ... eroxide dismutase (MSD1) identical to manganese ... superoxide dismutase [Arabidopsis thaliana] gi|327 ...

  1. Arabidopsis CDS blastp result: AK104030 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104030 001-020-C01 At3g10920.1 superoxide dismutase [Mn], mitochondrial (SODA) / manganese ... sup ... eroxide dismutase (MSD1) identical to manganese ... superoxide dismutase [Arabidopsis thaliana] gi|327 ...

  2. Arabidopsis CDS blastp result: AK104160 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104160 006-211-E09 At3g10920.1 superoxide dismutase [Mn], mitochondrial (SODA) / manganese ... sup ... eroxide dismutase (MSD1) identical to manganese ... superoxide dismutase [Arabidopsis thaliana] gi|327 ...

  3. Arabidopsis CDS blastp result: AK287459 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287459 J043019O07 At4g37000.1 68417.m05242 accelerated cell death ... 2 (ACD2) identical to accele ... rated cell death ... 2 (ACD2) GI:12484129 from [Arabidopsis thaliana] 4 ...

  4. Arabidopsis CDS blastp result: AK288034 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288034 J075140H07 At4g37000.1 68417.m05242 accelerated cell death ... 2 (ACD2) identical to accele ... rated cell death ... 2 (ACD2) GI:12484129 from [Arabidopsis thaliana] 5 ...

  5. Arabidopsis CDS blastp result: AK111576 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111576 J013075J23 At1g01510.1 C-terminal binding protein (ANGUSTIFOLIA) nearly id...entical to C-terminal binding protein ANGUSTIFOLIA [Arabidopsis thaliana] GI:15408535; contains Pfam profile

  6. Arabidopsis CDS blastp result: AK120838 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK120838 J023022B11 At1g01510.1 C-terminal binding protein (ANGUSTIFOLIA) nearly id...entical to C-terminal binding protein ANGUSTIFOLIA [Arabidopsis thaliana] GI:15408535; contains Pfam profile

  7. Arabidopsis CDS blastp result: AK111921 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111921 001-013-A10 At1g01510.1 C-terminal binding protein (ANGUSTIFOLIA) nearly i...dentical to C-terminal binding protein ANGUSTIFOLIA [Arabidopsis thaliana] GI:15408535; contains Pfam profil

  8. The Arabidopsis NPR1 gene confers broad-spectrum disease resistance in strawberry.

    Science.gov (United States)

    Silva, Katchen Julliany P; Brunings, Asha; Peres, Natalia A; Mou, Zhonglin; Folta, Kevin M

    2015-08-01

    Although strawberry is an economically important fruit crop worldwide, production of strawberry is limited by its susceptibility to a wide range of pathogens and the lack of major commercial cultivars with high levels of resistance to multiple pathogens. The objective of this study is to ectopically express the Arabidopsis thaliana NPR1 gene (AtNPR1) in the diploid strawberry Fragaria vesca L. and to test transgenic plants for disease resistance. AtNPR1 is a key positive regulator of the long-lasting broad-spectrum resistance known as systemic acquired resistance (SAR) and has been shown to confer resistance to a number of pathogens when overexpressed in Arabidopsis or ectopically expressed in several crop species. We show that ectopic expression of AtNPR1 in strawberry increases resistance to anthracnose, powdery mildew, and angular leaf spot, which are caused by different fungal or bacterial pathogens. The increased resistance is related to the relative expression levels of AtNPR1 in the transgenic plants. In contrast to Arabidopsis plants overexpressing AtNPR1, which grow normally and do not constitutively express defense genes, the strawberry transgenic plants are shorter than non-transformed controls, and most of them fail to produce runners and fruits. Consistently, most of the transgenic lines constitutively express the defense gene FvPR5, suggesting that the SAR activation mechanisms in strawberry and Arabidopsis are different. Nevertheless, our results indicate that overexpression of AtNPR1 holds the potential for generation of broad-spectrum disease resistance in strawberry. PMID:25812515

  9. Spectral reflectance relationships to leaf water stress

    Science.gov (United States)

    Ripple, William J.

    1986-01-01

    Spectral reflectance data were collected from detached snapbean leaves in the laboratory with a multiband radiometer. Four experiments were designed to study the spectral response resulting from changes in leaf cover, relative water content of leaves, and leaf water potential. Spectral regions included in the analysis were red (630-690 nm), NIR (760-900 nm), and mid-IR (2.08-2.35 microns). The red and mid-IR bands showed sensitivity to changes in both leaf cover and relative water content of leaves. The NIR was only highly sensitive to changes in leaf cover. Results provided evidence that mid-IR reflectance was governed primarily by leaf moisture content, although soil reflectance was an important factor when leaf cover was less than 100 percent. High correlations between leaf water potentials and reflectance were attributed to covariances with relative water content of leaves and leaf cover.

  10. YUCCA-mediated auxin biogenesis is required for cell fate transition occurring during de novo root organogenesis in Arabidopsis.

    Science.gov (United States)

    Chen, Lyuqin; Tong, Jianhua; Xiao, Langtao; Ruan, Ying; Liu, Jingchun; Zeng, Minhuan; Huang, Hai; Wang, Jia-Wei; Xu, Lin

    2016-07-01

    Many plant organs have the ability to regenerate a new plant after detachment or wounding via de novo organogenesis. During de novo root organogenesis from Arabidopsis thaliana leaf explants, endogenic auxin is essential for the fate transition of regeneration-competent cells to become root founder cells via activation of WUSCHEL-RELATED HOMEOBOX 11 (WOX11). However, the molecular events from leaf explant detachment to auxin-mediated cell fate transition are poorly understood. In this study, we used an assay to determine the concentration of indole-3-acetic acid (IAA) to provide direct evidence that auxin is produced after leaf explant detachment, a process that involves YUCCA (YUC)-mediated auxin biogenesis. Inhibition of YUC prevents expression of WOX11 and fate transition of competent cells, resulting in the blocking of rooting. Further analysis showed that YUC1 and YUC4 act quickly (within 4 hours) in response to wounding after detachment in both light and dark conditions and promote auxin biogenesis in both mesophyll and competent cells, whereas YUC5, YUC8, and YUC9 primarily respond in dark conditions. In addition, YUC2 and YUC6 contribute to rooting by providing a basal auxin level in the leaf. Overall, our study indicates that YUC genes exhibit a division of labour during de novo root organogenesis from leaf explants in response to multiple signals. PMID:27255928

  11. Arabidopsis CDS blastp result: AK073140 [KOME

    Lifescience Database Archive (English)

    Full Text Available me 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains a Ser/Thr protein...AK073140 J033022I01 At2g39840.1 serine/threonine protein phosphatase PP1 isozyme 4 (TOPP4) / phosphoprotein... phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphatase PP1 isozy... phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 1e-168 ...

  12. Arabidopsis CDS blastp result: AK120439 [KOME

    Lifescience Database Archive (English)

    Full Text Available me 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains a Ser/Thr protein...AK120439 J013098H20 At2g39840.1 serine/threonine protein phosphatase PP1 isozyme 4 (TOPP4) / phosphoprotein... phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphatase PP1 isozy... phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 1e-154 ...

  13. Arabidopsis CDS blastp result: AK121378 [KOME

    Lifescience Database Archive (English)

    Full Text Available me 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains a Ser/Thr protein...AK121378 J023127F14 At2g39840.1 serine/threonine protein phosphatase PP1 isozyme 4 (TOPP4) / phosphoprotein... phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphatase PP1 isozy... phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 1e-142 ...

  14. Arabidopsis CDS blastp result: AK063856 [KOME

    Lifescience Database Archive (English)

    Full Text Available yme 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains a Ser/Thr protein...AK063856 001-122-D05 At2g39840.1 serine/threonine protein phosphatase PP1 isozyme 4 (TOPP4) / phosphoprotein... phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphatase PP1 isoz... phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 6e-46 ...

  15. Terpene Specialized Metabolism in Arabidopsis thaliana

    OpenAIRE

    Tholl, Dorothea; Lee, Sungbeom

    2011-01-01

    Terpenes constitute the largest class of plant secondary (or specialized) metabolites, which are compounds of ecological function in plant defense or the attraction of beneficial organisms. Using biochemical and genetic approaches, nearly all Arabidopsis thaliana (Arabidopsis) enzymes of the core biosynthetic pathways producing the 5-carbon building blocks of terpenes have been characterized and closer insight has been gained into the transcriptional and posttranscriptional/translational mech...

  16. Optimum Delayed Retirement Credit

    OpenAIRE

    Sheshinski, Eytan

    2002-01-01

    A central question for pension design is how benefits should vary with the age of retirement beyond early eligibility age. It is often argued that in order to be neutral with respect to individual retirement decisions benefits should be actuarially fair, that is, the present value of additional contributions and benefits (’Delayed Retirement Credit’ - DRC) due to postponed retirement should be equal. We show that in a self-selection, asymmetric information model, because individual decisions ...

  17. Delay reduction: current status.

    OpenAIRE

    Fantino, E; Preston, R. A.; Dunn, R

    1993-01-01

    Delay-reduction theory states that the effectiveness of a stimulus as a conditioned reinforcer may be predicted most accurately by the reduction in time to primary reinforcement correlated with its onset. We review support for the theory and then discuss two new types of experiments that assess it. One compares models of choice in situations wherein the less preferred outcome is made more accessible; the other investigates whether frequency of conditioned reinforcement affects choice beyond t...

  18. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  19. Time-Delay Interferometry

    Science.gov (United States)

    Dhurandhar, Sanjeev V.; Tinto, Massimo

    2005-07-01

    Equal-arm interferometric detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers), the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called Time-Delay Interferometry (TDI). This article provides an overview of the theory and mathematical foundations of TDI as it will be implemented by the forthcoming space-based interferometers such as the Laser Interferometer Space Antenna (LISA) mission. We have purposely left out from this first version of our "Living Review" article on TDI all the results of more practical and experimental nature, as well as all the aspects of TDI that the data analysts will need to account for when analyzing the LISA TDI data combinations. Our forthcoming "second edition" of this review paper will include these topics.

  20. A method to improve leaf succulence quantification

    OpenAIRE

    André Mantovani

    1999-01-01

    Leaf succulence has important physiological and ecological implications. Currently it is quantified by Delf's index (fresh weight/leaf area) and fresh weight/ dry weight ratio. Both indeces are reconsidered and a new index is proposed. Shade and sun leaves from terrestrial, hemiepiphytic and epiphytic aroids were studied. Delf's formula, which does not consider dry weight, overestimated leaf succulence. As fresh weight / dry weight ratio (fw / dw) does not consider leaf area, plants with the ...

  1. Current Vaccine Shortages and Delays

    Science.gov (United States)

    ... CDC.gov . Vaccines and Immunizations Share Compartir Current Vaccine Shortages & Delays Last Updated December 7, 2015 On ... schedule are included in this update. Chart of Vaccines* in Delay or Shortage Vaccines are listed in ...

  2. 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.

  3. 7 CFR 29.2277 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2277 Leaf scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2277 Section 29.2277...

  4. 7 CFR 29.3526 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3526 Section 29.3526...

  5. 7 CFR 29.6023 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.6023 Section 29.6023 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Definitions § 29.6023 Leaf structure. The cell development of a leaf as indicated by...

  6. 7 CFR 29.2529 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2529 Leaf scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2529 Section 29.2529...

  7. 7 CFR 29.3034 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS...

  8. 7 CFR 29.6022 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or broken leaves. ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.6022 Section 29.6022...

  9. 7 CFR 29.1162 - Leaf (B Group).

    Science.gov (United States)

    2010-01-01

    ... Quality Green Leaf Immature, tight leaf structure, fleshy, lean in oil, narrow. Uniformity, 70 percent... Quality Lemon Leaf Ripe, firm leaf structure, medium body, lean in oil, weak color intensity, narrow... Quality Lemon Leaf Ripe, firm leaf structure, medium body, lean in oil, weak color intensity,...

  10. Early light-induced proteins protect Arabidopsis from photooxidative stress.

    Science.gov (United States)

    Hutin, Claire; Nussaume, Laurent; Moise, Nicolae; Moya, Ismaël; Kloppstech, Klaus; Havaux, Michel

    2003-04-15

    The early light-induced proteins (ELIPs) belong to the multigenic family of light-harvesting complexes, which bind chlorophyll and absorb solar energy in green plants. ELIPs accumulate transiently in plants exposed to high light intensities. By using an Arabidopsis thaliana mutant (chaos) affected in the posttranslational targeting of light-harvesting complex-type proteins to the thylakoids, we succeeded in suppressing the rapid accumulation of ELIPs during high-light stress, resulting in leaf bleaching and extensive photooxidative damage. Constitutive expression of ELIP genes in chaos before light stress resulted in ELIP accumulation and restored the phototolerance of the plants to the wild-type level. Free chlorophyll, a generator of singlet oxygen in the light, was detected by chlorophyll fluorescence lifetime measurements in chaos leaves before the symptoms of oxidative stress appeared. Our findings indicate that ELIPs fulfill a photoprotective function that could involve either the binding of chlorophylls released during turnover of pigment-binding proteins or the stabilization of the proper assembly of those proteins during high-light stress. PMID:12676998

  11. Mobile gene silencing in Arabidopsis is regulated by hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Dacheng Liang

    2014-12-01

    Full Text Available In plants and nematodes, RNAi can spread from cells from which it is initiated to other cells in the organism. The underlying mechanism controlling the mobility of RNAi signals is not known, especially in the case of plants. A genetic screen designed to recover plants impaired in the movement but not the production or effectiveness of the RNAi signal identified RCI3, which encodes a hydrogen peroxide (H2O2-producing type III peroxidase, as a key regulator of silencing mobility in Arabidopsis thaliana. Silencing initiated in the roots of rci3 plants failed to spread into leaf tissue or floral tissue. Application of exogenous H2O2 reinstated the spread in rci3 plants and accelerated it in wild-type plants. The addition of catalase or MnO2, which breaks down H2O2, slowed the spread of silencing in wild-type plants. We propose that endogenous H2O2, under the control of peroxidases, regulates the spread of gene silencing by altering plasmodesmata permeability through remodelling of local cell wall structure, and may play a role in regulating systemic viral defence.

  12. Cell-cell interactions during patterning of the Arabidopsis anther.

    Science.gov (United States)

    Feng, Xiaoqi; Dickinson, Hugh G

    2010-04-01

    Key steps in the evolution of the angiosperm anther include the patterning of the concentrically organized microsporangium and the incorporation of four such microsporangia into a leaf-like structure. Mutant studies in the model plant Arabidopsis thaliana are leading to an increasingly accurate picture of (i) the cell lineages culminating in the different cell types present in the microsporangium (the microsporocytes, the tapetum, and the middle and endothecial layers), and (ii) some of the genes responsible for specifying their fates. However, the processes that confer polarity on the developing anther and position the microsporangia within it remain unclear. Certainly, data from a range of experimental strategies suggest that hormones play a central role in establishing polarity and the patterning of the anther initial, and may be responsible for locating the microsporangia. But the fact that microsporangia were originally positioned externally suggests that their development is likely to be autonomous, perhaps with the reproductive cells generating signals controlling the growth and division of the investing anther epidermis. These possibilities are discussed in the context of the expression of genes which initiate and maintain male and female reproductive development, and in the perspective of our current views of anther evolution. PMID:20298223

  13. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Dhurandhar Sanjeev V.

    2005-07-01

    Full Text Available Equal-arm interferometric detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called Time-Delay Interferometry (TDI. This article provides an overview of the theory and mathematical foundations of TDI as it will be implemented by the forthcoming space-based interferometers such as the Laser Interferometer Space Antenna (LISA mission. We have purposely left out from this first version of our "Living Review" article on TDI all the results of more practical and experimental nature, as well as all the aspects of TDI that the data analysts will need to account for when analyzing the LISA TDI data combinations. Our forthcoming "second edition" of this review paper will include these topics.

  14. Vehicle barrier with access delay

    Science.gov (United States)

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  15. Concurrent Delay in Construction Disputes

    DEFF Research Database (Denmark)

    Cavaleri, Sylvie Cécile

    Delay is one of the issues most frequently encountered in today’s construction industry; it causes significant economic damage to all parties involved. Construction contracts, standard and bespoke, almost invariably consider delay from a perspective of single liability. If the event causing the...... period of delay can potentially be attributed to several events falling within both parties' spheres of responsibility, commonly termed concurrent delay, is rarely regulated in construction contracts in spite of its common occurrence. This book analyses both the theoretical foundations and the practical...... solutions to the issue of concurrent delay in a comparative perspective between common and civil law systems, with an emphasis on Danish and English law....

  16. Seed-to-seed growth of superdwarf wheat and arabidopsis using red light-emitting diodes (LED's): A report on baseline tests conducted for NASA's proposed Plant Research Unit (PRU)

    Science.gov (United States)

    Goins, G. D.; Yorio, N. C.; Sanwo, M. M.; Brown, C. S.

    1996-01-01

    To determine the influence of narrow-spectrum red light-emitting diodes (LED's) on plant growth and seed production, wheat (Triticum aestivum L.cv Superdwarf) and Arabidopsis (Arabidopsis thaliana (L.) Heynh, race Columbia) plants were grown under red LED's (peak emission 660 nm) and compared to plants grown under daylight fluorescent (white) light and red LED's supplemented with either 1 percent or 10 percent blue fluorescent (BF) light. Wheat growth under red LED's alone appeared normal, whereas Arabidopsis under red LED's alone developed curled leaf margins and a spiraling growth pattern. Both wheat and Arabidopsis under red LED's alone or red LED's + 1 percent BF light had significantly lower seed yield than plants grown under white light. However, the addition of 10 percent BF light to red LED's partially alleviated the adverse effect of red LED's on yield. Irrespective of the light treatment, viable seeds were produced by wheat(75-92 percent germination rate) and Arabidopsis (85-100 percent germination rate). These results indicate that wheat, and to a lesser extent Arabidopsis, can be successfully grown under red LED's alone, but supplemental blue light is required with red LED's to sufficiently match the growth characteristics and seed yield associated with plants grown under white light.

  17. Advances in Arabidopsis research in China from 2006 to 2007

    Institute of Scientific and Technical Information of China (English)

    LIANG Yan; ZUO JianRu; YANG WeiCai

    2007-01-01

    @@ Arabidopsis thaliana, a model plant species, has a number of advantages over other plant species as an experimental organism due to many of its genetic and genomic features. The Chinese Arabidopsis community has made significant contributions to plant biology research in recent years[1,2]. In 2006, studies of plant biology in China received more attention than ever before, especially those pertaining to Arabidopsis research. Here we briefly summarize recent advances in Arabidopsis research in China.

  18. Leaf spring assembly for wheel suspension

    Energy Technology Data Exchange (ETDEWEB)

    Nishiyama, K.; Mishima, Y.; Kuwayama, K.

    1986-09-16

    This patent describes a leaf spring assembly which consists of: a longitudinal leaf spring made of fiber reinforced plastics having a first surface to be applied with a tension force and a second surface to be applied with a compression force, the first surface of the leaf spring being a flat surface, and the second surface of the leaf spring being provided with a protrusion located substantially at the central portion of the leaf spring. The protrusion is made of a number of laminated short fibrous sheet-like materials saturated with synthetic resin, the short fibrous sheet-like materials of the protrusion being laminated independently and separately from reinforcement fibrous sheet-like materials in the leaf spring; a pair of pad members of elastic material attached to the first and second surfaces of the leaf spring; a pair of retainer plates attached to the first and second surfaces of the leaf spring through the pad members, one of the retainer plates being formed with an indented portion coupled with the protrusion of the leaf spring through one of the pad members without any clearance to clamp the leaf spring at its central portion and being further provided with a pair of protruded portions which are arranged adjacent to the indented portion to retain the paid member in place by engagement therewith; and means for clamping the retainer plates to the leaf spring and mounting the same on an axle housing.

  19. Effects of osmotic stress on antioxidant enzymes activities in leaf discs of PSAG12-IPT modified gerbera

    Institute of Scientific and Technical Information of China (English)

    LAI Qi-xian; BAO Zhi-yi; ZHU Zhu-jun; QIAN Qiong-qiu; MAO Bi-zeng

    2007-01-01

    Leaf senescence is often caused by water deficit and the chimeric gene PSAG12-IPT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, carotenoids, soluble protein and thiobarbituric acid reactive substance (TBARS) and antioxidant enzymes activities were investigated during leaf senescence of PSAG12-IPT modified gerbera induced by osmotic stress compared with the control plant (wild type). Leaf discs were incubated in 20%, 40% (w/v) polyethylene glycol (PEG) 6 000 nutrient solution for 20 h under continuous light [130 μmol/(m2·s)]. The results showed that the contents of chlorophylls, carotenoids and soluble protein were decreased by osmotic stress with the decrease being more pronounced at 40% PEG, but that, at the same PEG concentration the decrease in the transgenic plants was significantly lower than that in the control plant. The activities of superoxide dismutase (SOD), catalases (CAT), ascorbate peroxidase (APX),guaiacol peroxidase (GPX) and dehydroascorbate reductase (DHAR) were stimulated by PEG treatment. However, the increases were higher in PSAG12-IPT transgenic plants than in the control plants, particularly at 40% PEG treatment. Lipid peroxidation (TBARS content) was increased by PEG treatment with the increase being much lower in transgenic plant than in the control plant.It could be concluded that the increases in the activities of antioxidant enzymes including SOD, CAT, APX, GPX and DHAR were responsible for the delay of leaf senescence induced by osmotic stress.

  20. Identification and characterization of transcription factors regulating Arabidopsis HAK5.

    Science.gov (United States)

    Hong, Jong-Pil; Takeshi, Yoshizumi; Kondou, Youichi; Schachtman, Daniel P; Matsui, Minami; Shin, Ryoung

    2013-09-01

    Potassium (K) is an essential macronutrient for plant growth and reproduction. HAK5, an Arabidopsis high-affinity K transporter gene, plays an important role in K uptake. Its expression is up-regulated in response to K deprivation and is rapidly down-regulated when sufficient K levels have been re-established. To identify transcription factors regulating HAK5, an Arabidopsis TF FOX (Transcription Factor Full-length cDNA Over-eXpressor) library containing approximately 800 transcription factors was used to transform lines previously transformed with a luciferase reporter gene whose expression was driven by the HAK5 promoter. When grown under sufficient K levels, 87 lines with high luciferase activity were identified, and endogenous HAK5 expression was confirmed in 27 lines. Four lines overexpressing DDF2 (Dwarf and Delayed Flowering 2), JLO (Jagged Lateral Organs), TFII_A (Transcription initiation Factor II_A gamma chain) and bHLH121 (basic Helix-Loop-Helix 121) were chosen for further characterization by luciferase activity, endogenous HAK5 level and root growth in K-deficient conditions. Further analysis showed that the expression of these transcription factors increased in response to low K and salt stress. In comparison with controls, root growth under low K conditions was better in each of these four TF FOX lines. Activation of HAK5 expression by these four transcription factors required at least 310 bp of upstream sequence of the HAK5 promoter. These results indicate that at least these four transcription factors can bind to the HAK5 promoter in response to K limitation and activate HAK5 expression, thus allowing plants to adapt to nutrient stress. PMID:23825216

  1. Bacterial communities associated with the leaves and the roots of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Natacha Bodenhausen

    Full Text Available Diverse communities of bacteria inhabit plant leaves and roots and those bacteria play a crucial role for plant health and growth. Arabidopsis thaliana is an important model to study plant pathogen interactions, but little is known about its associated bacterial community under natural conditions. We used 454 pyrosequencing to characterize the bacterial communities associated with the roots and the leaves of wild A. thaliana collected at 4 sites; we further compared communities on the outside of the plants with communities in the endophytic compartments. We found that the most heavily sequenced bacteria in A. thaliana associated community are related to culturable species. Proteobacteria, Actinobacteria, and Bacteroidetes are the most abundant phyla in both leaf and root samples. At the genus level, sequences of Massilia and Flavobacterium are prevalent in both samples. Organ (leaf vs root and habitat (epiphytes vs endophytes structure the community. In the roots, richness is higher in the epiphytic communities compared to the endophytic compartment (P = 0.024, while the reverse is true for the leaves (P = 0.032. Interestingly, leaf and root endophytic compartments do not differ in richness, diversity and evenness, while they differ in community composition (P = 0.001. The results show that although the communities associated with leaves and roots share many bacterial species, the associated communities differ in structure.

  2. Establishment of an Indirect Genetic Transformation Method for Arabidopsis thaliana ecotype Bangladesh

    Directory of Open Access Journals (Sweden)

    Bulbul AHMED

    2011-11-01

    Full Text Available Arabidopsis thaliana is a small flowering plant belonging to the Brassicaceae family, which is adopted as a model plant for genetic research. Agrobacterium tumifaciensmediated transformation method for A. thaliana ecotype Bangladesh was established. Leaf discs of A. thaliana were incubated with A. tumefaciens strain LBA4404 containing chimeric nos. nptII. nos and intron-GUS genes. Following inoculation and co-cultivation, leaf discs were cultured on selection medium containing 50 mg/l kanamycin + 50 mg/l cefotaxime + 1.5 mg/l NAA and kanamycin resistant shoots were induced from the leaf discs after two weeks. Shoot regeneration was achieved after transferring the tissues onto fresh medium of the same combination. Finally, the shoots were rooted on MS medium containing 50 mg/l kanamycin. Incorporation and expression of the transgenes were confirmed by PCR analysis. Using this protocol, transgenic A. thaliana plants can be obtained and indicates that genomic transformation in higher plants is possible through insertion of desired gene. Although Agrobacterium mediated genetic transformation is established for A. thaliana, this study was the conducted to transform A. thaliana ecotype Bangladesh.

  3. A novel method for efficient and abundant production of Phytophthora brassicae zoospores on Brussels sprout leaf discs

    Directory of Open Access Journals (Sweden)

    Govers Francine

    2009-08-01

    Full Text Available Abstract Background Phytophthora species are notorious oomycete pathogens that cause diseases on a wide range of plants. Our understanding how these pathogens are able to infect their host plants will benefit greatly from information obtained from model systems representative for plant-Phytophthora interactions. One attractive model system is the interaction between Arabidopsis and Phytophthora brassicae. Under laboratory conditions, Arabidopsis can be easily infected with mycelial plugs as inoculum. In the disease cycle, however, sporangia or zoospores are the infectious propagules. Since the current P. brassicae zoospore isolation methods are generally regarded as inefficient, we aimed at developing an alternative method for obtaining high concentrations of P. brassicae zoospores. Results P. brassicae isolates were tested for pathogenicity on Brussels sprout plants (Brassica oleracea var. gemmifera. Microscopic examination of leaves, stems and roots infected with a GFP-tagged transformant of P. brassicae clearly demonstrated the susceptibility of the various tissues. Leaf discs were cut from infected Brussels sprout leaves, transferred to microwell plates and submerged in small amounts of water. In the leaf discs the hyphae proliferated and abundant formation of zoosporangia was observed. Upon maturation the zoosporangia released zoospores in high amounts and zoospore production continued during a period of at least four weeks. The zoospores were shown to be infectious on Brussels sprouts and Arabidopsis. Conclusion The in vitro leaf disc method established from P. brassicae infected Brussels sprout leaves facilitates convenient and high-throughput production of infectious zoospores and is thus suitable to drive small and large scale inoculation experiments. The system has the advantage that zoospores are produced continuously over a period of at least one month.

  4. The relationship of leaf photosynthetic traits - V cmax and J max - to leaf nitrogen, leaf phosphorus, and specific leaf area: a meta-analysis and modeling study.

    Science.gov (United States)

    Walker, Anthony P; Beckerman, Andrew P; Gu, Lianhong; Kattge, Jens; Cernusak, Lucas A; Domingues, Tomas F; Scales, Joanna C; Wohlfahrt, Georg; Wullschleger, Stan D; Woodward, F Ian

    2014-08-01

    Great uncertainty exists in the global exchange of carbon between the atmosphere and the terrestrial biosphere. An important source of this uncertainty lies in the dependency of photosynthesis on the maximum rate of carboxylation (V cmax) and the maximum rate of electron transport (J max). Understanding and making accurate prediction of C fluxes thus requires accurate characterization of these rates and their relationship with plant nutrient status over large geographic scales. Plant nutrient status is indicated by the traits: leaf nitrogen (N), leaf phosphorus (P), and specific leaf area (SLA). Correlations between V cmax and J max and leaf nitrogen (N) are typically derived from local to global scales, while correlations with leaf phosphorus (P) and specific leaf area (SLA) have typically been derived at a local scale. Thus, there is no global-scale relationship between V cmax and J max and P or SLA limiting the ability of global-scale carbon flux models do not account for P or SLA. We gathered published data from 24 studies to reveal global relationships of V cmax and J max with leaf N, P, and SLA. V cmax was strongly related to leaf N, and increasing leaf P substantially increased the sensitivity of V cmax to leaf N. J max was strongly related to V cmax, and neither leaf N, P, or SLA had a substantial impact on the relationship. Although more data are needed to expand the applicability of the relationship, we show leaf P is a globally important determinant of photosynthetic rates. In a model of photosynthesis, we showed that at high leaf N (3 gm(-2)), increasing leaf P from 0.05 to 0.22 gm(-2) nearly doubled assimilation rates. Finally, we show that plants may employ a conservative strategy of J max to V cmax coordination that restricts photoinhibition when carboxylation is limiting at the expense of maximizing photosynthetic rates when light is limiting. PMID:25473475

  5. Agrobacterium mediated transfer of a mutant Arabidopsis acetolactate synthase gene confers resistance to chlorsulfuron in chicory (Cichorium intybus L.).

    Science.gov (United States)

    Vermeulen, A; Vaucheret, H; Pautot, V; Chupeau, Y

    1992-06-01

    Leaf discs of C. intybus were inoculated with an Agrobacterium tumefaciens strain harboring a neomycin phosphotransferase (neo) gene for kanamycin resistance and a mutant acetolactate synthase gene (csr1-1) from Arabidopsis thaliana conferring resistance to sulfonylurea herbicides. A regeneration medium was optimized which permitted an efficient shoot regeneration from leaf discs. Transgenic shoots were selected on rooting medium containing 100 mg/l kanamycin sulfate. Integration of the csr1-1 gene into genomic DNA of kanamycin resistant chicory plants was confirmed by Southern blot hybridizations. Analysis of the selfed progenies (S1 and S2) of two independent transformed clones showed that kanamycin and chlorsulfuron resistances were inherited as dominant Mendelian traits. The method described here for producing transformed plants will allow new opportunities for chicory breeding. PMID:24203132

  6. Effects of Aerated Irrigation on Leaf Senescence at Late Growth Stage and Grain Yield of Rice

    Institute of Scientific and Technical Information of China (English)

    ZHU Lian-feng; Yu Sheng-miao; JIN Qian-yu

    2012-01-01

    With the japonica inbred cultivar Xiushui 09,indica hybrid combinations Guodao 6 and Liangyoupeijiu as materials,field experiments were conducted in 2007 and 2008 to study the effects of aerated irrigation on leaf senescence at late growth stage and grain yield of rice.The dissolved oxygen concentration of aerated water evidently increased and decreased at a slow rate.The soil oxidation-reduction potential under aerated irrigation treatment was significantly higher than that of the CK,contributing to significant increases in effective panicles,seed setting rate and grain yield.In addition,the aerated irrigation improved root function,increased superoxide dismutase activity and decreased malondialdehyde content in flag leaves at post-flowering,which delayed leaf senescence process,prolonged leaf functional activity and led to enhanced grain filling.

  7. Mining the active proteome of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Renier A. L. Van Der Hoorn

    2011-11-01

    Full Text Available Assigning functions to the >30.000 proteins encoded by the Arabidopsis genome is a challenging task of the Arabidopsis Functional Genomics Network. Although genome-wide technologies like proteomics and transcriptomics have generated a wealth of information that significantly accelerated gene annotation, protein activities are poorly predicted by transcript or protein levels as protein activities are post-translationally regulated. To directly display protein activities in Arabidopsis proteomes, we developed and applied Activity-based Protein Profiling (ABPP. ABPP is based on the use of small molecule probes that react with the catalytic residues of distinct protein classes in an activity-dependent manner. Labeled proteins are separated and detected from proteins gels and purified and identified by mass spectrometry. Using probes of six different chemotypes we have displayed of activities of 76 Arabidopsis proteins. These proteins represent over ten different protein classes that contain over 250 Arabidopsis proteins, including cysteine- serine- and metallo-proteases, lipases, acyltransferases, and the proteasome. We have developed methods for identification of in vivo labeled proteins using click-chemistry and for in vivo imaging with fluorescent probes. In vivo labeling has revealed novel protein activities and unexpected subcellular activities of the proteasome. Labeling of extracts displayed several differential activities e.g. of the proteasome during immune response and methylesterases during infection. These studies illustrate the power of ABPP to display the functional proteome and testify to a successful interdisciplinary collaboration involving chemical biology, organic chemistry and proteomics.

  8. Bioavailability of nanoparticulate hematite to Arabidopsis thaliana

    International Nuclear Information System (INIS)

    The environmental effects and bioavailability of nanoparticulate iron (Fe) to plants are currently unknown. Here, plant bioavailability of synthesized hematite Fe nanoparticles was evaluated using Arabidopsis thaliana (A. thaliana) as a model. Over 56-days of growing wild-type A. thaliana, the nanoparticle-Fe and no-Fe treatments had lower plant biomass, lower chlorophyll concentrations, and lower internal Fe concentrations than the Fe-treatment. Results for the no-Fe and nanoparticle-Fe treatments were consistently similar throughout the experiment. These results suggest that nanoparticles (mean diameter 40.9 nm, range 22.3–67.0 nm) were not taken up and therefore not bioavailable to A. thaliana. Over 14-days growing wild-type and transgenic (Type I/II proton pump overexpression) A. thaliana, the Type I plant grew more than the wild-type in the nanoparticle-Fe treatment, suggesting Type I plants cope better with Fe limitation; however, the nanoparticle-Fe and no-Fe treatments had similar growth for all plant types. -- Highlights: ► Iron nanoparticles were synthesized and assessed for bioavailability to Arabidopsis. ► Arabidopsis grew better in the presence of EDTA-bound iron than nanoparticulate iron. ► Arabidopsis grew the same in the presence of nanoparticulate iron compared to no iron. -- Synthesized iron nanoparticles were not bioavailable to Arabidopsis thaliana in agar nutrient media

  9. The mitochondrial monothiol glutaredoxin S15 is essential for iron-sulfur protein maturation in Arabidopsis thaliana

    Science.gov (United States)

    Moseler, Anna; Aller, Isabel; Wagner, Stephan; Nietzel, Thomas; Przybyla-Toscano, Jonathan; Mühlenhoff, Ulrich; Lill, Roland; Berndt, Carsten; Rouhier, Nicolas; Schwarzländer, Markus; Meyer, Andreas J.

    2015-01-01

    The iron-sulfur cluster (ISC) is an ancient and essential cofactor of many proteins involved in electron transfer and metabolic reactions. In Arabidopsis, three pathways exist for the maturation of iron-sulfur proteins in the cytosol, plastids, and mitochondria. We functionally characterized the role of mitochondrial glutaredoxin S15 (GRXS15) in biogenesis of ISC containing aconitase through a combination of genetic, physiological, and biochemical approaches. Two Arabidopsis T-DNA insertion mutants were identified as null mutants with early embryonic lethal phenotypes that could be rescued by GRXS15. Furthermore, we showed that recombinant GRXS15 is able to coordinate and transfer an ISC and that this coordination depends on reduced glutathione (GSH). We found the Arabidopsis GRXS15 able to complement growth defects based on disturbed ISC protein assembly of a yeast Δgrx5 mutant. Modeling of GRXS15 onto the crystal structures of related nonplant proteins highlighted amino acid residues that after mutation diminished GSH and subsequently ISC coordination, as well as the ability to rescue the yeast mutant. When used for plant complementation, one of these mutant variants, GRXS15K83/A, led to severe developmental delay and a pronounced decrease in aconitase activity by approximately 65%. These results indicate that mitochondrial GRXS15 is an essential protein in Arabidopsis, required for full activity of iron-sulfur proteins. PMID:26483494

  10. Performance of Late Sown Wheat in Response to Foliar Application of Moringa oleifera Lam. Leaf Extract Rendimiento de Trigo Sembrado Tarde en Respuesta a la Aplicación Foliar de Extracto de Hojas de Moringa oleifera Lam.

    OpenAIRE

    Azra Yasmeen; Shahzad Maqsood Ahmed Basra; Rashid Ahmad; Abdul Wahid

    2012-01-01

    A rise in temperature during early spring inducing early maturity is a key yield-reducing factor in late sown wheat (Triticum aestivum L.). Moringa oleifera Lam. leaves are rich in zeatin, a cytokinin that plays a role in delaying leaf senescence, in addition to other growth-enhancing compounds such as ascorbates, phenolics, and minerals. The objective of this study was to optimize dose and optimum growth stage for foliar-applied moringa leaf extract (MLE) and its role in delaying leaf senesc...

  11. The Arabidopsis male-sterile mutant dde2-2 is defective in the ALLENE OXIDE SYNTHASE gene encoding one of the key enzymes of the jasmonic acid biosynthesis pathway

    DEFF Research Database (Denmark)

    von Malek, Bernadette; van der Graaff, Eric; Schneitz, Kay; Keller, Beat

    2002-01-01

    The Arabidopsis thaliana (L.) Heynh. mutant delayed-dehiscence2-2 (dde2-2) was identified in an En1/Spm1 transposon-induced mutant population screened for plants showing defects in fertility. The dde2-2 mutant allele is defective in the anther dehiscence process and filament elongation and thus e...

  12. Synchronizing time delay systems using variable delay in coupling

    International Nuclear Information System (INIS)

    Highlights: → Delay and anticipation in coupling function varies with system dynamics. → Delay or anticipation of the synchronized state is independent of system delay. → Stability analysis developed is quite general. → We demonstrate enhanced security in communication. → Generalized synchronization possible over a wide range of parameter mismatch. - Abstract: We present a mechanism for synchronizing time delay systems using one way coupling with a variable delay in coupling that is reset at finite intervals. We present the analysis of the error dynamics that helps to isolate regions of stability of the synchronized state in the parameter space of interest for single and multiple delays. We supplement this by numerical simulations in a standard time delay system like Mackey Glass system. This method has the advantage that it can be adjusted to be delay or anticipatory in synchronization with a time which is independent of the system delay. We demonstrate the use of this method in communication using the bi channel scheme. We show that since the synchronizing channel carries information from transmitter only at intervals of reset time, it is not susceptible to an easy reconstruction.

  13. INVESTIGATION OF STRESSES IN MASTER LEAF OF LEAF SPRING BY FEM AND ITS EXPERIMENTAL VERIFICATION

    OpenAIRE

    R. B. Charde; Dr. D. V. Bhope

    2012-01-01

    The main component of leaf spring is master leaf and it is subjected to cyclic loading. There are many causes of master leaf failure. The maximum stress induced in the master leaf is at support. Due to non geometric linearity and large deflection behavior the stress may be occurred at any section over the span of leaf spring. Hence inthis work evaluation of stresses in master leaf over the span is studied using finite element method and strain gauge technique. The stress analysis of half cant...

  14. Structure-activity relationships of trichothecene toxins in an Arabidopsis thaliana leaf assay

    Science.gov (United States)

    Many Fusarium species produce trichothecenes, sesquiterpene epoxides that differ in patterns of oxygenation and esterification at carbon positions C-3, C-4, C-7, C-8, and C-15. For the first comprehensive and quantitative comparison of the effects of oxygenation and esterification on trichothecene ...

  15. Auxin depletion from the leaf axil conditions competence for axillary meristem formation in Arabidopsis and tomato

    OpenAIRE

    Wang, Quan; Kohlen, Wouter; Rossmann, Susanne; Vernoux, Teva

    2014-01-01

    The enormous variation in architecture of flowering plants is based to a large extent on their ability to form new axes of growth throughout their life span. Secondary growth is initiated from groups of pluripotent cells, called meristems, which are established in the axils of leaves. Such meristems form lateral organs and develop into a side shoot or a flower, depending on the developmental status of the plant and environmental conditions. The phytohormone auxin is well known to play an impo...

  16. The cytokinin response factors modulate root and shoot growth and promote leaf senescence in Arabidopsis

    Czech Academy of Sciences Publication Activity Database

    Raines, T.; Shanks, C.; Cheng, C.Y.; McPherson, D.; Argueso, C.T.; Kim, H.J.; Franco-Zorrilla, J.M.; Lopez-Vidriero, I.; Solano, R.; Vaňková, Radomíra; Schaller, G.E.; Kieber, J.J.

    2016-01-01

    Roč. 85, č. 1 (2016), s. 134-147. ISSN 0960-7412 Institutional support: RVO:61389030 Keywords : cytokinin * two-component signaling * transcription factors Subject RIV: EF - Botanics Impact factor: 5.972, year: 2014

  17. Long delayed radio echoes

    International Nuclear Information System (INIS)

    This thesis describes an experimental program carried out at Stanford over a five-year period. The experiment involved transmitting a radio signal, and tape-recording the output of a receiver gang-tuned with the transmitter for the following 30 s interval. The tapes were later audited for possible LDE. Although none of the possible LDE received reproduces exactly the transmitted signal, many exhibit features that seem unlikely to have been generated except by an LDE mechanism. A mechanism for producing LDE has been studied which involves signal propagation in an electron plasma wave mode at very low group velocity. Modifications to the simplified theory leading to prediction of longer delays are discussed

  18. Recent Progress in Arabidopsis Research in China: A Preface

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hong Xu

    2006-01-01

    @@ In 2002, a workshop on Arabidopsis research in China was held in Shanghai, when a small group of Chinese plant scientists was working on this model species. Since then, we have witnessed the rapid growth of Arabidopsis research in China. This special issue of Journal of Integrative Plant Biology is dedicated exclusively to the Fourth Workshop on Arabidopsis Research in China, scheduled on November 30, 2005, in Beijing. In addition to reports collected in this special issue, the Chinese Arabidopsis community has been able to make significant contributions to many research fields. Here, I briefly summarize recent advances in Arabidopsis research in China.

  19. Novel Synthetic Promoters from the Cestrum Yellow Leaf Curling Virus.

    Science.gov (United States)

    Sahoo, Dipak Kumar; Sarkar, Shayan; Maiti, Indu B; Dey, Nrisingha

    2016-01-01

    Constitutive promoters direct gene expression uniformly in most tissues and cells at all stages of plant growth and development; they confer steady levels of transgene expression in plant cells and hence their demand is high in plant biology. The gene silencing due to promoter homology can be avoided by either using diverse promoters isolated from different plant and viral genomes or by designing synthetic promoters. The aim of this chapter was to describe the basic protocols needed to develop and analyze novel, synthetic, nearly constitutive promoters from Cestrum yellow leaf curling virus (CmYLCV) through promoter/leader deletion and activating cis-sequence analysis. We also describe the methods to evaluate the strength of the promoters efficiently in various transient expression systems like agroinfiltration assay, gene-gun method, and assay in tobacco protoplasts. Besides, the detailed methods for developing transgenic plants (tobacco and Arabidopsis) for evaluation of the promoter using the GUS reporter gene are also described. The detailed procedure for electrophoretic mobility shift assay (EMSA) coupled with super-shift EMSA analysis are also described for showing the binding of tobacco transcription factor, TGA1a to cis-elements in the CmYLCV distal promoter region. PMID:27557764

  20. Do pH changes in the leaf apoplast contribute to rapid inhibition of leaf elongation rate by water stress? Comparison of stress responses induced by polyethylene glycol and down-regulation of root hydraulic conductivity.

    Science.gov (United States)

    Ehlert, Christina; Plassard, Claude; Cookson, Sarah Jane; Tardieu, François; Simonneau, Thierry

    2011-08-01

    We have dissected the influences of apoplastic pH and cell turgor on short-term responses of leaf growth to plant water status, by using a combination of a double-barrelled pH-selective microelectrodes and a cell pressure probe. These techniques were used, together with continuous measurements of leaf elongation rate (LER), in the (hidden) elongating zone of the leaves of intact maize plants while exposing roots to various treatments. Polyethylene glycol (PEG) reduced water availability to roots, while acid load and anoxia decreased root hydraulic conductivity. During the first 30 min, acid load and anoxia induced moderate reductions in leaf growth and turgor, with no effect on leaf apoplastic pH. PEG stopped leaf growth, while turgor was only partially reduced. Rapid alkalinization of the apoplast, from pH 4.9 ± 0.3 to pH 5.8 ± 0.2 within 30 min, may have participated to this rapid growth reduction. After 60 min, leaf growth inhibition correlated well with turgor reduction across all treatments, supporting a growth limitation by hydraulics. We conclude that apoplastic alkalinization may transiently impair the control of leaf growth by cell turgor upon abrupt water stress, whereas direct hydraulic control of growth predominates under moderate conditions and after a 30-60 min delay following imposition of water stress. PMID:21477119

  1. The arabidopsis cyclic nucleotide interactome

    KAUST Repository

    Donaldson, Lara

    2016-05-11

    Background Cyclic nucleotides have been shown to play important signaling roles in many physiological processes in plants including photosynthesis and defence. Despite this, little is known about cyclic nucleotide-dependent signaling mechanisms in plants since the downstream target proteins remain unknown. This is largely due to the fact that bioinformatics searches fail to identify plant homologs of protein kinases and phosphodiesterases that are the main targets of cyclic nucleotides in animals. Methods An affinity purification technique was used to identify cyclic nucleotide binding proteins in Arabidopsis thaliana. The identified proteins were subjected to a computational analysis that included a sequence, transcriptional co-expression and functional annotation analysis in order to assess their potential role in plant cyclic nucleotide signaling. Results A total of twelve cyclic nucleotide binding proteins were identified experimentally including key enzymes in the Calvin cycle and photorespiration pathway. Importantly, eight of the twelve proteins were shown to contain putative cyclic nucleotide binding domains. Moreover, the identified proteins are post-translationally modified by nitric oxide, transcriptionally co-expressed and annotated to function in hydrogen peroxide signaling and the defence response. The activity of one of these proteins, GLYGOLATE OXIDASE 1, a photorespiratory enzyme that produces hydrogen peroxide in response to Pseudomonas, was shown to be repressed by a combination of cGMP and nitric oxide treatment. Conclusions We propose that the identified proteins function together as points of cross-talk between cyclic nucleotide, nitric oxide and reactive oxygen species signaling during the defence response.

  2. Location Estimation using Delayed Measurements

    DEFF Research Database (Denmark)

    Bak, Martin; Larsen, Thomas Dall; Nørgård, Peter Magnus;

    1998-01-01

    When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new techn...... technique to a sensor fusion system for estimating the location of an autonomous guided vehicle. The system fuses encoder and vision measurements in an extended Kalman filter. Results from experiments in a real environment are reported...

  3. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Bennett, Matthew R. [Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77204, USA and Institute of Biosciences and Bioengineering, Rice University, Houston, Texas 77005 (United States); Josić, Krešimir [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204 (United States)

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  4. Post-CTS Delay Insertion

    OpenAIRE

    Jianchao Lu; Baris Taskin

    2010-01-01

    A post-clock-tree-synthesis (post-CTS) optimization method is proposed that suggests delay insertion at the leaves of the clock tree in order to implement a limited version of clock skew scheduling. Delay insertion is limited on each clock tree branch simultaneous with a global monitoring of the total amount of delay insertion. The delay insertion for nonzero clock skew operation is performed only at the clock sinks in order to preserve the structure and the optimizations implemented in the c...

  5. Static Analysis of Hybrid Composite Leaf Spring

    Directory of Open Access Journals (Sweden)

    B.Arun*1,

    2014-06-01

    Full Text Available Leaf spring is a simple form of suspension spring used to absorb vibrations induced during the motion of a vehicle. The automobile industry has shown increased interest in the replacement of steel leaf spring (65Si7 with hybrid composite leaf spring with Jute/E-glass/Epoxy due to high strength to weight ratio, higher stiffness, high impact energy absorption and lesser stresses. This research is aimed to investigate the suitability of natural and synthetic fiber reinforced hybrid composite material in automobile leaf spring application. hybrid composite leaf spring with Jute/E-glass/Epoxy due to high strength to weight ratio, higher stiffness, high impact energy absorption and lesser stresses. This research is aimed to investigate the suitability of natural and synthetic fiber reinforced hybrid composite material in automobile leaf spring application.

  6. Arabidopsis CDS blastp result: AK243152 [KOME

    Lifescience Database Archive (English)

    Full Text Available ase PP1 isozyme 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains...P1 isozyme 4 (TOPP4) / phosphoprotein phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphat... a Ser/Thr protein phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 1e-154 ... ...AK243152 J100032N02 At2g39840.1 68415.m04893 serine/threonine protein phosphatase P

  7. Arabidopsis CDS blastp result: AK288069 [KOME

    Lifescience Database Archive (English)

    Full Text Available ase PP1 isozyme 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains...P1 isozyme 4 (TOPP4) / phosphoprotein phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphat... a Ser/Thr protein phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 6e-70 ... ...AK288069 J075158N05 At2g39840.1 68415.m04893 serine/threonine protein phosphatase P

  8. Gibberellins control fruit patterning in Arabidopsis thaliana.

    Science.gov (United States)

    Arnaud, Nicolas; Girin, Thomas; Sorefan, Karim; Fuentes, Sara; Wood, Thomas A; Lawrenson, Tom; Sablowski, Robert; Østergaard, Lars

    2010-10-01

    The Arabidopsis basic helix-loop-helix (bHLH) proteins INDEHISCENT (IND) and ALCATRAZ (ALC) specify tissues required for fruit opening that have major roles in seed dispersal and plant domestication. Here, we show that synthesis of the phytohormone gibberellin is a direct and necessary target of IND, and that ALC interacts directly with DELLA repressors, which antagonize ALC function but are destabilized by gibberellin. Thus, the gibberellin/DELLA pathway has a key role in patterning the Arabidopsis fruit, and the interaction between DELLA and bHLH proteins, previously shown to connect gibberellin and light responses, is a versatile regulatory module also used in tissue patterning. PMID:20889713

  9. Expression of a High Mobility Group Protein Isolated from Cucumis sativus Affects the Germination of Arabidopsis thaliana under Abiotic Stress Conditions

    Institute of Scientific and Technical Information of China (English)

    Ji Young Jang; Kyung Jin Kwak; Hunseung Kang

    2008-01-01

    Although high mobility group B (HMGB) proteins have been identified from a variety of plant species, their importance and functional roles in plant responses to changing environmental conditions are largely unknown. Here, we investigated the functional roles of a CsHMGB isolated from cucumber (Cucurnis sativus L.) in plant responses to environmental stimuli. Under normal growth conditions or when subjected to cold stress, no differences in plant growth were found between the wild.type and transgenic Arabidopsis thaliana overexpressing CsHMGB. By contrast, the transgenic Arabidopsis plants displayed retarded germination compared with the wild-type plants when grown under high salt or dehydration stress conditions. Germination of the transgenic plants was delayed by the addition of abscisic acid (ABA), implying that CsHMGB affects germination through an ABA-dependent way. The expression of CsHMGB had affected only the germination stage, and CsHMGB did not affect the seedling growth of the transgenic plants under the stress conditions. The transcript levels of several germination-responsive genes were modulated by the expression of CsHMGB in Arabidopsis. Taken together, these results suggest that ectopic expression of a CsHMGB in Arabidopsis modulates the expression of several germination-responsive genes, and thereby affects the germination of Arabidopsis plants under different stress conditions.

  10. The better growth phenotype of DvGS1-transgenic arabidopsis thaliana is attributed to the improved efficiency of nitrogen assimilation

    Directory of Open Access Journals (Sweden)

    Zhu Chenguang

    2015-01-01

    Full Text Available The overexpression of the algal glutamine synthetase (GS gene DvGS1 in Arabidopsis thaliana resulted in higher plant biomass and better growth phenotype. The purpose of this study was to recognize the biological mechanism for the growth improvement of DvGS1-transgenic Arabidopsis. A series of molecular and biochemical investigations related to nitrogen and carbon metabolism in the DvGS1-transgenic line was conducted. Analysis of nitrogen use efficiency (NUE-related gene transcription and enzymatic activity revealed that the transcriptional level and enzymatic activity of the genes encoding GS, glutamate synthase, glutamate dehydrogenase, alanine aminotransferase and aspartate aminotransferase, were significantly upregulated, especially from leaf tissues of the DvGS1-transgenic line under two nitrate conditions. The DvGS1-transgenic line showed increased total nitrogen content and decreased carbon: nitrogen ratio compared to wild-type plants. Significant reduced concentrations of free nitrate, ammonium, sucrose, glucose and starch, together with higher concentrations of total amino acids, individual amino acids (glutamate, aspartate, asparagine, methionine, soluble proteins and fructose in leaf tissues confirmed that the DvGS1-transgenic line demonstrated a higher efficiency of nitrogen assimilation, which subsequently affected carbon metabolism. These improved metabolisms of nitrogen and carbon conferred the DvGS1-transgenic Arabidopsis higher NUE, more biomass and better growth phenotype compared with the wild-type plants.

  11. Static Analysis of Hybrid Composite Leaf Spring

    OpenAIRE

    B.Arun*1,; P. Chithambaranathan2

    2014-01-01

    Leaf spring is a simple form of suspension spring used to absorb vibrations induced during the motion of a vehicle. The automobile industry has shown increased interest in the replacement of steel leaf spring (65Si7) with hybrid composite leaf spring with Jute/E-glass/Epoxy due to high strength to weight ratio, higher stiffness, high impact energy absorption and lesser stresses. This research is aimed to investigate the suitability of natural and synthetic fiber reinforced hybrid comp...

  12. Comparative leaf anatomy of Heisteria (Olacaceae)

    OpenAIRE

    Baas, P; Kool, R.

    1983-01-01

    The leaf anatomy of all 33 species of Heisteria is described, based on a study of 143 specimens. There is a considerable amount of diversity in stomatal type (anisocytic, anomocytic, cyclocytic, laterocytic or paracytic), in occurrence and type of mesophyll sclereids, and of fibre bundles along the leaf margin. Outline and thickness of anticlinal epidermal cell walls, cuticle thickness, crystal complement, and stomatal size also vary, but often below the species level. The leaf anatomical div...

  13. Anaerobic Capacities of Leaf Litter

    OpenAIRE

    Kusel, K.; Drake, H L

    1996-01-01

    Leaf litter displayed a capacity to spontaneously form organic acids, alcohols, phenolic compounds, H(inf2), and CO(inf2) when incubated anaerobically at 20(deg)C either as buffered suspensions or in a moistened condition in microcosms. Acetate was the predominant organic product formed regardless of the degree of litter decomposition. Initial rates of acetate formation in litter suspensions and microcosms approximated 2.6 and 0.53 (mu)mol of acetate per g (dry weight) of litter per h, respec...

  14. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  15. In Silico Identification of Co-transcribed Core Cell Cycle Regulators and Transcription Factors in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Regulatory networks involving transcription factors and core cell cycle regulators are expected to play crucial roles in plant growth and development. In this report, we describe the identification of two groups of co-transcribed core cell cycle regulators and transcription factors via a two-step in silico screening. The core cell cycle regulators include TARDY ASYNCHRONOUS MEIOSIS (CYCA1;2), CYCB1;1, CYCB2;1, CDKB1;2, and CDKB2;2 while the transcription factors include CURLY LEAF, AINTEGUMENTA, a MYB protein, two Forkhead-associated domain proteins, and a SCARECROW family protein. Promoter analysis revealed a potential web of cross- and self-regulations among the identified proteins. Because one criterion for screening for these genes is that they are predominantly transcribed in young organs but not in mature organs, these genes are likely to be particularly involved in Arabidopsis organ growth.

  16. 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.

  17. A role in immunity for Arabidopsis cysteine protease RD21, the ortholog of the tomato immune protease C14.

    Directory of Open Access Journals (Sweden)

    Takayuki Shindo

    Full Text Available Secreted papain-like Cys proteases are important players in plant immunity. We previously reported that the C14 protease of tomato is targeted by cystatin-like EPIC proteins that are secreted by the oomycete pathogen Phytophthora infestans (Pinf during infection. C14 has been under diversifying selection in wild potato species coevolving with Pinf and reduced C14 levels result in enhanced susceptibility for Pinf. Here, we investigated the role C14-EPIC-like interactions in the natural pathosystem of Arabidopsis with the oomycete pathogen Hyaloperonospora arabidopsidis (Hpa. In contrast to the Pinf-solanaceae pathosystem, the C14 orthologous protease of Arabidopsis, RD21, does not evolve under diversifying selection in Arabidopsis, and rd21 null mutants do not show phenotypes upon compatible and incompatible Hpa interactions, despite the evident lack of a major leaf protease. Hpa isolates express highly conserved EPIC-like proteins during infections, but it is unknown if these HpaEPICs can inhibit RD21 and one of these HpaEPICs even lacks the canonical cystatin motifs. The rd21 mutants are unaffected in compatible and incompatible interactions with Pseudomonas syringae pv. tomato, but are significantly more susceptible for the necrotrophic fungal pathogen Botrytis cinerea, demonstrating that RD21 provides immunity to a necrotrophic pathogen.

  18. The sunflower transcription factor HaHB11 improves yield, biomass and tolerance to flooding in transgenic Arabidopsis plants.

    Science.gov (United States)

    Cabello, Julieta V; Giacomelli, Jorge I; Piattoni, Claudia V; Iglesias, Alberto A; Chan, Raquel L

    2016-03-20

    HaHB11 is a member of the sunflower homeodomain-leucine zipper I subfamily of transcription factors. The analysis of a sunflower microarray hybridized with RNA from HaHB11-transformed leaf-disks indicated the regulation of many genes encoding enzymes from glycolisis and fermentative pathways. A 1300bp promoter sequence, fused to the GUS reporter gene, was used to transform Arabidopsis plants showing an induction of expression after flooding treatments, concurrently with HaHB11 regulation by submergence in sunflower. Arabidopsis transgenic plants expressing HaHB11 under the control of the CaMV 35S promoter and its own promoter were obtained and these plants exhibited significant increases in rosette and stem biomass. All the lines produced more seeds than controls and particularly, those of high expression level doubled seeds yield. Transgenic plants also showed tolerance to flooding stress, both to submergence and waterlogging. Carbohydrates contents were higher in the transgenics compared to wild type and decreased less after submergence treatments. Finally, transcript levels of selected genes involved in glycolisis and fermentative pathways as well as the corresponding enzymatic activities were assessed both, in sunflower and transgenic Arabidopsis plants, before and after submergence. Altogether, the present work leads us to propose HaHB11 as a biotechnological tool to improve crops yield, biomass and flooding tolerance. PMID:26876611

  19. Sequence and nitrate regulation of the Arabidopsis thaliana mRNA encoding nitrate reductase, a metalloflavoprotein with three functional domains

    International Nuclear Information System (INIS)

    The sequence of nitrate reductase mRNA from the plant Arabidopsis thaliana has been determined. A 3.0-kilobase-long cDNA was isolated from a λgt10 cDNA library of Arabidopsis leaf poly(A)+ RNA. The cDNA hybridized to a 3.2-kilobase mRNA whose level increased 15-fold in response to treatment of the plant with nitrate. An open reading frame encoding a 917 amino acid protein was found in the sequence. This protein is very similar to tobacco nitrate reductase, being >80% identical within a section of 450 amino acids. By comparing the Arabidopsis protein sequence with other protein sequences, three functional domains were deduced: (i) a molybdenum-pterin-binding domain that is similar to the molybdenum-pterin-binding domain of rat liver sulfite oxidase, (ii) a heme-binding domain that is similar to proteins in the cytochrome b5 superfamily, and (iii) an FAD-binding domain that is similar to NADH-cytochrome b5 reductase

  20. The pharmaceutics from the foreign empire: the molecular pharming of the prokaryotic staphylokinase in Arabidopsis thaliana plants.

    Science.gov (United States)

    Hnatuszko-Konka, Katarzyna; Łuchniak, Piotr; Wiktorek-Smagur, Aneta; Gerszberg, Aneta; Kowalczyk, Tomasz; Gatkowska, Justyna; Kononowicz, Andrzej K

    2016-07-01

    Here, we present the application of microbiology and biotechnology for the production of recombinant pharmaceutical proteins in plant cells. To the best of our knowledge and belief it is one of few examples of the expression of the prokaryotic staphylokinase (SAK) in the eukaryotic system. Despite the tremendous progress made in the plant biotechnology, most of the heterologous proteins still accumulate to low concentrations in plant tissues. Therefore, the composition of expression cassettes to assure economically feasible level of protein production in plants remains crucial. The aim of our research was obtaining a high concentration of the bacterial anticoagulant factor-staphylokinase, in Arabidopsis thaliana seeds. The coding sequence of staphylokinase was placed under control of the β-phaseolin promoter and cloned between the signal sequence of the seed storage protein 2S2 and the carboxy-terminal KDEL signal sequence. The engineered binary vector pATAG-sak was introduced into Arabidopsis thaliana plants via Agrobacterium tumefaciens-mediated transformation. Analysis of the subsequent generations of Arabidopsis seeds revealed both presence of the sak and nptII transgenes, and the SAK protein. Moreover, a plasminogen activator activity of staphylokinase was observed in the protein extracts from seeds, while such a reaction was not observed in the leaf extracts showing seed-specific activity of the β-phaseolin promoter. PMID:27263008

  1. Overexpression of a New Putative Membrane Protein Gene AtMRB1 Results in Organ Size Enlargement in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Hua Guan; Dingming Kang; Min Fan; Zhangliang Chen; LiJia Qu

    2009-01-01

    Arabidopsis AtMRB1 is predicted to encode a novel protein of 432 amino acid residues in length, with four putative trans-membrane domains. In the present study, characterization of AtMRB1 is conducted. Green fluorescent protein (GFP) fusion protein assay showed that AtMRB1 was located in the plasma membrane. Transgenic lines overexprsssing AtMRB1 driven by a CaMV 35S promoter were generated. Statistic analysis showed that, during the seedling stage, the organ sizes of the transgenic lines including hypocotyl length, root length and root weight were significantly larger than those of the wild type plants under both light and dark conditions. In the adult plant stage, the AtMRB1 overexpressor plants were found to have larger organ sizes in terms of leaf length and width, and increased number of cauline leaves and branches when bolting. Further observation indicated that the larger leaf size phenotype was due to a larger number of mesophyll cells, the size of which was not altered. Quantitative real-time polymerase chain reaction analysis showed that the transcription of ANT, ROT3 and GRF5 were upregulated in the AtMRB1-overexpressor plants. These data suggest that AtMRB1 is possibly a positive regulator of organ size development in Arabidopsis, mainly through cell number control.

  2. Altered regulation of lipid biosynthesis in a mutant of Arabidopsis deficient in chloroplast glycerol-3-phosphate acyltransferase activity

    International Nuclear Information System (INIS)

    The leaf membrane lipids of many plant species, including Arabidopsis thaliana (L.) Heynh., are synthesized by two complementary pathways that are associated with the chloroplast and the endoplasmic reticulum. By screening directly for alterations in lipid acyl-group composition, the authors have identified several mutants of Arabidopsis that lack the plastid pathway because of a deficiency in activity of the first enzyme in the plastid pathway of glycerolipid synthesis, acyl-ACP:sn-glycerol-3-phosphate acyltransferase. The lesion results in an increased synthesis of lipids by the cytoplasmic pathway that largely compensates for the loss of the plastid pathway and provides nearly normal amounts of all the lipids required for chloroplast biogenesis. However, the fatty acid composition of the leaf membrane lipids of the mutants is altered because the acyltransferases associated with the two pathways normally exhibit different substrate specificities. The remarkable flexibility of the system provides an insight into the nature of the regulatory mechanisms that allocate lipids for membrane biogenesis

  3. Transcriptomic analysis of Arabidopsis overexpressing flowering locus T driven by a meristem-specific promoter that induces early flowering.

    Science.gov (United States)

    Duplat-Bermúdez, L; Ruiz-Medrano, R; Landsman, D; Mariño-Ramírez, L; Xoconostle-Cázares, B

    2016-08-10

    Here we analyzed in leaves the effect of FT overexpression driven by meristem-specific KNAT1 gene homolog of Arabidopsis thaliana (Lincoln et al., 1994; Long et al., 1996) on the transcriptomic response during plant development. Our results demonstrated that meristematic FT overexpression generates a phenotype with an early flowering independent of photoperiod when compared with wild type (WT) plants. Arabidopsis FT-overexpressor lines (AtFTOE) did not show significant differences compared with WT lines neither in leaf number nor in rosette diameter up to day 21, when AtFTOE flowered. After this period AtFTOE plants started flower production and no new rosette leaves were produced. Additionally, WT plants continued on vegetative stage up to day 40, producing 12-14 rosette leaves before flowering. Transcriptomic analysis of rosette leaves studied by sequencing Illumina RNA-seq allowed us to determine the differential expression in mature leaf rosette of 3652 genes, being 626 of them up-regulated and 3026 down-regulated. Overexpressed genes related with flowering showed up-regulated transcription factors such as MADS-box that are known as flowering markers in meristem and which overexpression has been related with meristem identity preservation and the transition from vegetative to floral stage. Genes related with sugar transport have shown a higher demand of monosaccharides derived from the hydrolysis of sucrose to glucose and probably fructose, which can also be influenced by reproductive stage of AtFTOE plants. PMID:27154816

  4. Transcriptomic analysis of Arabidopsis overexpressing flowering locus T driven by a meristem-specific promoter that induces early flowering

    Science.gov (United States)

    Duplat-Bermúdez, L.; Ruiz-Medrano, R.; Landsman, D.; Mariño-Ramírez, L.; Xoconostle-Cázares, B.

    2016-01-01

    Here we analyzed in leaves the effect of FT overexpression driven by meristem-specific KNAT1 gene homolog of Arabidopsis thaliana (Lincoln et al., 1994; Long et al., 1996) on the transcriptomic response during plant development. Our results demonstrated that meristematic FT overexpression generates a phenotype with an early flowering independent of photoperiod when compared with wild type (WT) plants. Arabidopsis FT-overexpressor lines (AtFTOE) did not show significant differences compared with WT lines neither in leaf number nor in rosette diameter up to day 21, when AtFTOE flowered. After this period AtFTOE plants started flower production and no new rosette leaves were produced. Additionally, WT plants continued on vegetative stage up to day 40, producing 12–14 rosette leaves before flowering. Transcriptomic analysis of rosette leaves studied by sequencing Illumina RNA-seq allowed us to determine the differential expression in mature leaf rosette of 3652 genes, being 626 of them up-regulated and 3026 down-regulated. Overexpressed genes related with flowering showed up-regulated transcription factors such as MADS-box that are known as flowering markers in meristem and which overexpression has been related with meristem identity preservation and the transition from vegetative to floral stage. Genes related with sugar transport have shown a higher demand of monosaccharides derived from the hydrolysis of sucrose to glucose and probably fructose, which can also be influenced by reproductive stage of AtFTOE plants. PMID:27154816

  5. On the role of a Lipid-Transfer Protein. Arabidopsis ltp3 mutant is compromised in germination and seedling growth.

    Science.gov (United States)

    Pagnussat, Luciana A; Oyarburo, Natalia; Cimmino, Carlos; Pinedo, Marcela L; de la Canal, Laura

    2015-01-01

    Plant Lipid-Transfer Proteins (LTPs) exhibit the ability to reversibly bind/transport lipids in vitro. LTPs have been involved in diverse physiological processes but conclusive evidence on their role has only been presented for a few members, none of them related to seed physiology. Arabidopsis seeds rely on storage oil breakdown to supply carbon skeletons and energy for seedling growth. Here, Arabidopsis ltp3 mutant was analyzed for its ability to germinate and for seedling establishment. Ltp3 showed delayed germination and reduced germination frequency. Seedling growth appeared reduced in the mutant but this growth restriction was rescued by the addition of an exogenous carbon supply, suggesting a defective oil mobilization. Lipid breakdown analysis during seedling growth revealed a differential profile in the mutant compared to the wild type. The involvement of LTP3 in germination and seedling growth and its relationship with the lipid transfer ability of this protein is discussed. PMID:26479260

  6. Delayed unlatching mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Bzorgi, Fariborz M.

    2015-05-19

    In various embodiments an apparatus is presented for securing a structure such as a door, window, hatch, or gate that moves between an open and a closed position relative to a fixed structure to provide or deny access to a compartment, a room, an outdoor area, or a facility. Various embodiments provide a delay in opening the closure of sufficient duration to frustrate a rapid activation that might be desired by a person who is attempting to pass through the closure for some illicit purpose. Typically, hydraulics are used to activate the apparatus and no electrical energy or electronic signals are employed. In one embodiment, a plurality of actuations of a hand lever operates a hydraulic pump that moves a locking bolt from a first position in which a locking bolt is engaged with a recess in the fixed structure (preventing opening of a gate) to a second position in which the locking bolt is disengaged from the recess to permit opening of the gate.

  7. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne;

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... the period between 1999 and 2006. A history of radiation therapy was associated with increased risk of severe capsular contracture for 1- and 2-stage procedures, with adjusted hazard ratios (HR) of 3.3 (95% confidence interval [CI]: 0.9-12.4) and 7.2 (95% CI: 2.4-21.4), respectively. Similarly, a...... history of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy...

  8. Delay Adjusted Incidence Infographic

    Science.gov (United States)

    This Infographic shows the National Cancer Institute SEER Incidence Trends. The graphs show the Average Annual Percent Change (AAPC) 2002-2011. For Men, Thyroid: 5.3*,Liver & IBD: 3.6*, Melanoma: 2.3*, Kidney: 2.0*, Myeloma: 1.9*, Pancreas: 1.2*, Leukemia: 0.9*, Oral Cavity: 0.5, Non-Hodgkin Lymphoma: 0.3*, Esophagus: -0.1, Brain & ONS: -0.2*, Bladder: -0.6*, All Sites: -1.1*, Stomach: -1.7*, Larynx: -1.9*, Prostate: -2.1*, Lung & Bronchus: -2.4*, and Colon & Rectum: -3/0*. For Women, Thyroid: 5.8*, Liver & IBD: 2.9*, Myeloma: 1.8*, Kidney: 1.6*, Melanoma: 1.5, Corpus & Uterus: 1.3*, Pancreas: 1.1*, Leukemia: 0.6*, Brain & ONS: 0, Non-Hodgkin Lymphoma: -0.1, All Sites: -0.1, Breast: -0.3, Stomach: -0.7*, Oral Cavity: -0.7*, Bladder: -0.9*, Ovary: -0.9*, Lung & Bronchus: -1.0*, Cervix: -2.4*, and Colon & Rectum: -2.7*. * AAPC is significantly different from zero (p<.05). Rates were adjusted for reporting delay in the registry. www.cancer.gov Source: Special section of the Annual Report to the Nation on the Status of Cancer, 1975-2011.

  9. Geometric time delay interferometry

    International Nuclear Information System (INIS)

    The space-based gravitational-wave observatory LISA, a NASA-ESA mission to be launched after 2012, will achieve its optimal sensitivity using time delay interferometry (TDI), a LISA-specific technique needed to cancel the otherwise overwhelming laser noise in the interspacecraft phase measurements. The TDI observables of the Michelson and Sagnac types have been interpreted physically as the virtual measurements of a synthesized interferometer. In this paper, I present Geometric TDI, a new and intuitive approach to extend this interpretation to all TDI observables. Unlike the standard algebraic formalism, Geometric TDI provides a combinatorial algorithm to explore exhaustively the space of second-generation TDI observables (i.e., those that cancel laser noise in LISA-like interferometers with time-dependent arm lengths). Using this algorithm, I survey the space of second-generation TDI observables of length (i.e., number of component phase measurements) up to 24, and I identify alternative, improved forms of the standard second-generation TDI observables. The alternative forms have improved high-frequency gravitational-wave sensitivity in realistic noise conditions (because they have fewer nulls in the gravitational-wave and noise response functions), and are less susceptible to instrumental gaps and glitches (because their component phase measurements span shorter time periods)

  10. Geometric Time Delay Interferometry

    CERN Document Server

    Vallisneri, M

    2005-01-01

    The space-based gravitational-wave observatory LISA, a NASA--ESA mission to be launched after 2012, will achieve its optimal sensitivity using Time Delay Interferometry (TDI), a LISA-specific technique needed to cancel the otherwise overwhelming laser noise in the inter-spacecraft phase measurements. In this paper I present_Geometric TDI_, a new, intuitive approach to derive the TDI observables and to understand them as the virtual measurements of a synthesized multi-beam interferometer. Unlike the standard algebraic formalism, Geometric TDI provides a combinatorial algorithm to explore exhaustively the space of _second-generation_ TDI observables (i.e., those that cancel laser noise in LISA-like interferometers with time-dependent armlengths). Using this algorithm, I survey the space of second-generation TDI observables of length (i.e., number of component phase measurements) up to 24, and I identify alternative, improved forms of the standard second-generation TDI observables. The alternative forms have imp...

  11. An intergenic region shared by At4g35985 and At4g35987 in Arabidopsis thaliana is a tissue specific and stress inducible bidirectional promoter analyzed in transgenic arabidopsis and tobacco plants.

    Directory of Open Access Journals (Sweden)

    Joydeep Banerjee

    Full Text Available On chromosome 4 in the Arabidopsis genome, two neighboring genes (calmodulin methyl transferase At4g35987 and senescence associated gene At4g35985 are located in a head-to-head divergent orientation sharing a putative bidirectional promoter. This 1258 bp intergenic region contains a number of environmental stress responsive and tissue specific cis-regulatory elements. Transcript analysis of At4g35985 and At4g35987 genes by quantitative real time PCR showed tissue specific and stress inducible expression profiles. We tested the bidirectional promoter-function of the intergenic region shared by the divergent genes At4g35985 and At4g35987 using two reporter genes (GFP and GUS in both orientations in transient tobacco protoplast and Agro-infiltration assays, as well as in stably transformed transgenic Arabidopsis and tobacco plants. In transient assays with GFP and GUS reporter genes the At4g35985 promoter (P85 showed stronger expression (about 3.5 fold compared to the At4g35987 promoter (P87. The tissue specific as well as stress responsive functional nature of the bidirectional promoter was evaluated in independent transgenic Arabidopsis and tobacco lines. Expression of P85 activity was detected in the midrib of leaves, leaf trichomes, apical meristemic regions, throughout the root, lateral roots and flowers. The expression of P87 was observed in leaf-tip, hydathodes, apical meristem, root tips, emerging lateral root tips, root stele region and in floral tissues. The bidirectional promoter in both orientations shows differential up-regulation (2.5 to 3 fold under salt stress. Use of such regulatory elements of bidirectional promoters showing spatial and stress inducible promoter-functions in heterologous system might be an important tool for plant biotechnology and gene stacking applications.

  12. Magnetic bearing optical delay line

    NARCIS (Netherlands)

    Dool, T.C. van den; Kamphues, F.G.; Fouss, B.; Henrioulle, K.; Hogenhuis, H.

    2004-01-01

    TNO TPD, in close cooperation with Micromega-Dynamics and Dutch Space, has developed an advanced Optical Delay Line (ODL) for use in PRIMA, GENIE and other ground based interferometers. The delay line design is modular and flexible, which makes scaling for other applications a relatively easy task.

  13. Consumer Procrastination and Purchase Delay

    OpenAIRE

    Darpy, Denis

    2000-01-01

    Recent research on purchase delay have developed numerous situational and individual causes. This paper proposes Consumer Procrastination to conceptualize the individual factor which influence people to chronically delay their purchases. Consumer Procrastination is measured with a new scale. An experiment is designed to show the importance of its impact on the decision to not choose along with context effects.

  14. #FakeNobelDelayReasons

    CERN Multimedia

    2013-01-01

    Tuesday’s hour-long delay of the Nobel Prize in Physics announcement was (and still is) quite the cause for speculation. But on the Twittersphere, it was simply the catalyst for some fantastic puns, so-bad-they're-good physics jokes and other shenanigans. Here are some of our favourite #FakeNobelDelayReasons.    

  15. Delayed Reinforcement of Operant Behavior

    Science.gov (United States)

    Lattal, Kennon A.

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement but also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between…

  16. The Quantitative Basis of the Arabidopsis Innate Immune System to Endemic Pathogens Depends on Pathogen Genetics.

    Science.gov (United States)

    Corwin, Jason A; Copeland, Daniel; Feusier, Julie; Subedy, Anushriya; Eshbaugh, Robert; Palmer, Christine; Maloof, Julin; Kliebenstein, Daniel J

    2016-02-01

    The most established model of the eukaryotic innate immune system is derived from examples of large effect monogenic quantitative resistance to pathogens. However, many host-pathogen interactions involve many genes of small to medium effect and exhibit quantitative resistance. We used the Arabidopsis-Botrytis pathosystem to explore the quantitative genetic architecture underlying host innate immune system in a population of Arabidopsis thaliana. By infecting a diverse panel of Arabidopsis accessions with four phenotypically and genotypically distinct isolates of the fungal necrotroph B. cinerea, we identified a total of 2,982 genes associated with quantitative resistance using lesion area and 3,354 genes associated with camalexin production as measures of the interaction. Most genes were associated with resistance to a specific Botrytis isolate, which demonstrates the influence of pathogen genetic variation in analyzing host quantitative resistance. While known resistance genes, such as receptor-like kinases (RLKs) and nucleotide-binding site leucine-rich repeat proteins (NLRs), were found to be enriched among associated genes, they only account for a small fraction of the total genes associated with quantitative resistance. Using publically available co-expression data, we condensed the quantitative resistance associated genes into co-expressed gene networks. GO analysis of these networks implicated several biological processes commonly connected to disease resistance, including defense hormone signaling and ROS production, as well as novel processes, such as leaf development. Validation of single gene T-DNA knockouts in a Col-0 background demonstrate a high success rate (60%) when accounting for differences in environmental and Botrytis genetic variation. This study shows that the genetic architecture underlying host innate immune system is extremely complex and is likely able to sense and respond to differential virulence among pathogen genotypes. PMID:26866607

  17. Structural diversity and transcription of class III peroxidases from Arabidopsis thaliana.

    Science.gov (United States)

    Welinder, Karen G; Justesen, Annemarie F; Kjaersgård, Inger V H; Jensen, Rikke B; Rasmussen, Søren K; Jespersen, Hans M; Duroux, Laurent

    2002-12-01

    Understanding peroxidase function in plants is complicated by the lack of substrate specificity, the high number of genes, their diversity in structure and our limited knowledge of peroxidase gene transcription and translation. In the present study we sequenced expressed sequence tags (ESTs) encoding novel heme-containing class III peroxidases from Arabidopsis thaliana and annotated 73 full-length genes identified in the genome. In total, transcripts of 58 of these genes have now been observed. The expression of individual peroxidase genes was assessed in organ-specific EST libraries and compared to the expression of 33 peroxidase genes which we analyzed in whole plants 3, 6, 15, 35 and 59 days after sowing. Expression was assessed in root, rosette leaf, stem, cauline leaf, flower bud and cell culture tissues using the gene-specific and highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR). We predicted that 71 genes could yield stable proteins folded similarly to horseradish peroxidase (HRP). The putative mature peroxidases derived from these genes showed 28-94% amino acid sequence identity and were all targeted to the endoplasmic reticulum by N-terminal signal peptides. In 20 peroxidases these signal peptides were followed by various N-terminal extensions of unknown function which are not present in HRP. Ten peroxidases showed a C-terminal extension indicating vacuolar targeting. We found that the majority of peroxidase genes were expressed in root. In total, class III peroxidases accounted for an impressive 2.2% of root ESTs. Rather few peroxidases showed organ specificity. Most importantly, genes expressed constitutively in all organs and genes with a preference for root represented structurally diverse peroxidases (< 70% sequence identity). Furthermore, genes appearing in tandem showed distinct expression profiles. The alignment of 73 Arabidopsis peroxidase sequences provides an easy access to the identification of orthologous peroxidases

  18. Light acclimation potential and carry-over effects vary among three evergreen tree species with contrasting patterns of leaf emergence and maturation.

    Science.gov (United States)

    Ishii, Hiroaki; Ohsugi, Yoshihiro

    2011-08-01

    We compared light acclimation potential among three evergreen broadleaved species with contrasting patterns of shoot elongation, leaf emergence and leaf maturation. Understory saplings were transferred to a high-light environment before bud break, grown for 13 months, and then transferred back to the understory to observe subsequent carry-over effects. Acclimation potential was highest and sapling mortality was lowest for Cinnamomum japonicum Sieb. ex Nakai. Indeterminate growth and successive leaf emergence allowed this species to acclimate to both high and low light by adjusting leaf production as well as leaf properties. Sapling mortality occurred after both transfers for Camellia japonica L., which also has indeterminate growth and successive leaf emergence. In this species, carry-over effects were observed at the individual level, but leaf-level acclimation potential was high. Acclimation potential was lowest and sapling mortality occurred soon after the transfer to high light for Quercus glauca Thunb. ex Murray. Determinate growth and flush-type leaf emergence resulted in significant carry-over effects in this species. Indeterminate growth and successive leaf emergence increase whole-plant acclimation potential by extending the period of growth and architectural development during the growing season. Similarly, we inferred that delayed leaf maturation, observed in many evergreen species, increases the acclimation potential of current-year leaves by extending the period of leaf development. In evergreen species, the acclimation potential of preexisting leaves determines the role that leaf turnover plays in whole-plant light acclimation, resulting in diverse strategies for light acclimation among species, as observed in this study. PMID:21868403

  19. Posttranslational Modifications of FERREDOXIN-NADP+ OXIDOREDUCTASE in Arabidopsis Chloroplasts1[W][OPEN

    Science.gov (United States)

    Lehtimäki, Nina; Koskela, Minna M.; Dahlström, Käthe M.; Pakula, Eveliina; Lintala, Minna; Scholz, Martin; Hippler, Michael; Hanke, Guy T.; Rokka, Anne; Battchikova, Natalia; Salminen, Tiina A.; Mulo, Paula

    2014-01-01

    Rapid responses of chloroplast metabolism and adjustments to photosynthetic machinery are of utmost importance for plants’ survival in a fluctuating environment. These changes may be achieved through posttranslational modifications of proteins, which are known to affect the activity, interactions, and localization of proteins. Recent studies have accumulated evidence about the crucial role of a multitude of modifications, including acetylation, methylation, and glycosylation, in the regulation of chloroplast proteins. Both of the Arabidopsis (Arabidopsis thaliana) leaf-type FERREDOXIN-NADP+ OXIDOREDUCTASE (FNR) isoforms, the key enzymes linking the light reactions of photosynthesis to carbon assimilation, exist as two distinct forms with different isoelectric points. We show that both AtFNR isoforms contain multiple alternative amino termini and undergo light-responsive addition of an acetyl group to the α-amino group of the amino-terminal amino acid of proteins, which causes the change in isoelectric point. Both isoforms were also found to contain acetylation of a conserved lysine residue near the active site, while no evidence for in vivo phosphorylation or glycosylation was detected. The dynamic, multilayer regulation of AtFNR exemplifies the complex regulatory network systems controlling chloroplast proteins by a range of posttranslational modifications, which continues to emerge as a novel area within photosynthesis research. PMID:25301888

  20. Two alanine aminotranferases link mitochondrial glycolate oxidation to the major photorespiratory pathway in Arabidopsis and rice.

    Science.gov (United States)

    Niessen, Markus; Krause, Katrin; Horst, Ina; Staebler, Norma; Klaus, Stephanie; Gaertner, Stefanie; Kebeish, Rashad; Araujo, Wagner L; Fernie, Alisdair R; Peterhansel, Christoph

    2012-04-01

    The major photorespiratory pathway in higher plants is distributed over chloroplasts, mitochondria, and peroxisomes. In this pathway, glycolate oxidation takes place in peroxisomes. It was previously suggested that a mitochondrial glycolate dehydrogenase (GlcDH) that was conserved from green algae lacking leaf-type peroxisomes contributes to photorespiration in Arabidopsis thaliana. Here, the identification of two Arabidopsis mitochondrial alanine:glyoxylate aminotransferases (ALAATs) that link glycolate oxidation to glycine formation are described. By this reaction, the mitochondrial side pathway produces glycine from glyoxylate that can be used in the glycine decarboxylase (GCD) reaction of the major pathway. RNA interference (RNAi) suppression of mitochondrial ALAAT did not result in major changes in metabolite pools under standard conditions or enhanced photorespiratroy flux, respectively. However, RNAi lines showed reduced photorespiratory CO(2) release and a lower CO(2) compensation point. Mitochondria isolated from RNAi lines are incapable of converting glycolate to CO(2), whereas simultaneous overexpression of GlcDH and ALAATs in transiently transformed tobacco leaves enhances glycolate conversion. Furthermore, analyses of rice mitochondria suggest that the side pathway for glycolate oxidation and glycine formation is conserved in monocotyledoneous plants. It is concluded that the photorespiratory pathway from green algae has been functionally conserved in higher plants. PMID:22268146

  1. Conserved non-coding regulatory signatures in Arabidopsis co-expressed gene modules.

    Directory of Open Access Journals (Sweden)

    Jacob B Spangler

    Full Text Available Complex traits and other polygenic processes require coordinated gene expression. Co-expression networks model mRNA co-expression: the product of gene regulatory networks. To identify regulatory mechanisms underlying coordinated gene expression in a tissue-enriched context, ten Arabidopsis thaliana co-expression networks were constructed after manually sorting 4,566 RNA profiling datasets into aerial, flower, leaf, root, rosette, seedling, seed, shoot, whole plant, and global (all samples combined groups. Collectively, the ten networks contained 30% of the measurable genes of Arabidopsis and were circumscribed into 5,491 modules. Modules were scrutinized for cis regulatory mechanisms putatively encoded in conserved non-coding sequences (CNSs previously identified as remnants of a whole genome duplication event. We determined the non-random association of 1,361 unique CNSs to 1,904 co-expression network gene modules. Furthermore, the CNS elements were placed in the context of known gene regulatory networks (GRNs by connecting 250 CNS motifs with known GRN cis elements. Our results provide support for a regulatory role of some CNS elements and suggest the functional consequences of CNS activation of co-expression in specific gene sets dispersed throughout the genome.

  2. Biocontrol activity of Paenibacillus polymyxa AC-1 against Pseudomonas syringae and its interaction with Arabidopsis thaliana.

    Science.gov (United States)

    Hong, Chi Eun; Kwon, Suk Yoon; Park, Jeong Mee

    2016-04-01

    Paenibacillus polymyxa AC-1 (AC-1) is a plant growth-promoting rhizobacterium (PGPR) that has been used as a soil inoculant for biocontrol of plant pathogenic fungi and to promote plant growth. In this study, we examine the effects of AC-1 on the bacterial phytopathogen Pseudomonas syringae and internal colonization of AC-1 by counting bacterial populations that colonize plants. AC-1 inhibited the growth of both P. syringae pv. tomato DC3000 (Pst) and P. syringae pv. tabaci (Pta) in a concentration-dependent manner in in vitro assays. Upon treatment of AC-1 dropping at root tip of axenically grown Arabidopsis, we found that most of the AC-1 was detected in interior of leaves of Arabidiopsis plants rather than roots after 5 days post infection, indicating systemic spreading of AC-1 occur. We examined further AC-1 colonization patterns in Arabidopsis mutants deficient in phytohormone signaling pathways. These results indicated that abscisic acid (ABA) and jasmonic acid (JA) signaling pathways positively and negatively contributed, respectively, to AC-1 colonization of leaves, whereas epiphytic accumulation of AC-1 around root tissues was not affected. This study shows that AC-1 is an effective biocontrol agent to suppress P. syringae growth, possibly owing to its colonization patterns as a leaf-inhabiting endophyte. The results showed in this work will help to expand our understanding of the mode of action of AC-1 as a biological control agent and consequently, its application in agriculture. PMID:26946374

  3. NADPH Thioredoxin Reductase C Controls the Redox Status of Chloroplast 2-Cys Peroxiredoxins in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Kerstin Kirchsteiger; Pablo Pulido; Maricruz Gonzalez; Francisco Javier Cejudo

    2009-01-01

    Chloroplast 2-Cys peroxiredoxins (2-Cys Prxs) are efficiently reduced by NADPH Thioredoxin reductase C (NTRC). To investigate the effect of light/darkness on NTRC function, the content of abundant plastidial enzymes, Rubisco, glutamine synthetase (GS), and 2-Cys Prxs was analyzed during two consecutive days in Arabidopsis wild-type and ntrc mutant plants. No significant difference of the content of these proteins was observed during the day or the night in wild-type and mutant plants. NTRC deficiency caused a lower content of fully reduced 2-Cys Prxs, which was undetectable in darkness, suggesting that NTRC is the most important pathway for 2-Cys Prx reduction, probably the only one during the night. Arabidopsis contains two plastidial 2-Cys Prxs, A and B, for which T-DNA insertion lines were characterized showing the same phenotype as wild-type plants. Two-dimensional gel analysis of leaf extracts from these mutants allowed the identification of basic and acidic isoforms of 2-Cys Prx A and B. In-vitro assays and mass spectrometry analysis showed that the acidic isoform of both proteins is produced by overoxidation of the peroxidatic Cys residue to sulfinic acid. 2-Cys Prx overoxidation was lower in the NTRC mutant. These results show the important function of NTRC to maintain the redox equilibrium of chloroplast 2-Cys Prxs.

  4. Coordination of Plastid and Light Signaling Pathways upon Development of Arabidopsis Leaves under Various Photoperiods

    Institute of Scientific and Technical Information of China (English)

    Anna Lepist(o); Eevi Rintam(a)ki

    2012-01-01

    Plants synchronize their cellular and physiological functions according to the photoperiod(the length of the light period)in the cycle of 24 h.Photoperiod adjusts several traits in the plant life cycle,including flowering and senescence in annuals and seasonal growth cessation in perennials.Photoperiodic development is controlled by the coordinated action of photoreceptors and the circadian clock.During the past 10 years,remarkable progress has been made in understanding the molecular mechanism of the circadian clock,especially with regard to the transition of Arabidopsis from the vegetative growth to the reproductive phase.Besides flowering photoperiod also modifies plant photosynthetic structures and traits.Light signals controlling biogenesis of chloroplasts and development of leaf photosynthetic structures are perceived both by photoreceptors and in chloroplasts.In this review,we provide evidence suggesting that the photoperiodic development of Arabidopsis leaves mimics the acclimation of plant to various light intensities.Furthermore,the chloroplast-to-nucleus retrograde signals that adjust acclimation to light intensity are proposed to contribute also to the signaling pathways that control photoperiodic acclimation of leaves.

  5. Time-delay damping theory

    Institute of Scientific and Technical Information of China (English)

    洪峰

    2002-01-01

    In this paper, existing damping theories are briefly reviewed. On the basis of the existing damping theories, a new kind of damping theory, i.e., the time-delay damping theory, is developed. In the time-delay damping theory, the damping force is considered to be directly proportional to the increment of displacement. The response analysis of an SDOF time-delay damping system is carried out, and the methods for obtaining the solution for a time-delay damping system in the time domain as well as the frequency domain are given. The comparison between results from different damping theories shows that the time-delay damping theory is both reasonable and convenient.

  6. Functional characterization and hormonal regulation of the PHEOPHYTINASE gene LpPPH controlling leaf senescence in perennial ryegrass.

    Science.gov (United States)

    Zhang, Jing; Yu, Guohui; Wen, Wuwu; Ma, Xiqing; Xu, Bin; Huang, Bingru

    2016-02-01

    Chlorophyll (Chl) degradation occurs naturally during leaf maturation and senescence, and can be induced by stresses, both processes involving the regulation of plant hormones. The objective of this study was to determine the functional roles and hormonal regulation of a gene encoding pheophytin pheophorbide hydrolyase (PPH) that catabolizes Chl degradation during leaf senescence in perennial grass species. A PPH gene, LpPPH, was cloned from perennial ryegrass (Lolium perenne L.). LpPPH was localized in the chloroplast. Overexpressing LpPPH accelerated Chl degradation in wild tobacco, and rescued the stay-green phenotype of the Arabidopsis pph null mutant. The expression level of LpPPH was positively related to the extent of leaf senescence. Exogenous application of abscisic acid (ABA) and ethephon (an ethylene-releasing agent) accelerated the decline in Chl content in leaves of perennial ryegrass, whereas cytokinin (CK) and aminoethoxyvinylglycine (AVG; an ethylene biosynthesis inhibitor) treatments suppressed leaf senescence, corresponding to the up- or down-regulation of LpPPH expression. The promoters of five orthologous PPH genes were predicted to share conserved cis-elements potentially recognized by transcription factors in the ABA and CK pathways. Taken together, the results suggested that LpPPH-mediated Chl breakdown could be regulated positively by ABA and ethylene, and negatively by CK, and LpPPH could be a direct downstream target gene of transcription factors in the ABA and CK signaling pathways. PMID:26643195

  7. Arabidopsis CDS blastp result: AK066771 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK066771 J013083K07 At1g01170.1 ozone-responsive stress-related protein, putative s...imilar to stress-related ozone-induced protein AtOZI1 (GI:790583) [Arabidopsis thaliana]; contains 1 predicted transmembrane domain; 2e-29 ...

  8. Arabidopsis CDS blastp result: AK059353 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK059353 001-026-D01 At1g01170.1 ozone-responsive stress-related protein, putative ...similar to stress-related ozone-induced protein AtOZI1 (GI:790583) [Arabidopsis thaliana]; contains 1 predicted transmembrane domain; 2e-29 ...

  9. Arabidopsis CDS blastp result: AK059160 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK059160 001-023-D05 At1g01170.1 ozone-responsive stress-related protein, putative ...similar to stress-related ozone-induced protein AtOZI1 (GI:790583) [Arabidopsis thaliana]; contains 1 predicted transmembrane domain; 3e-28 ...

  10. Arabidopsis CDS blastp result: AK242849 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242849 J090072M15 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  11. Arabidopsis CDS blastp result: AK288959 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288959 J090084E19 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  12. Arabidopsis CDS blastp result: AK243008 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243008 J090097H12 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  13. Arabidopsis CDS blastp result: AK288072 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288072 J075161I05 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  14. Arabidopsis CDS blastp result: AK243178 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243178 J100036P15 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  15. Arabidopsis CDS blastp result: AK243505 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243505 J100074N19 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  16. Arabidopsis CDS blastp result: AK287577 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287577 J065037N08 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  17. Protease gene families in Populus and Arabidopsis

    Directory of Open Access Journals (Sweden)

    Jansson Stefan

    2006-12-01

    Full Text Available Abstract Background Proteases play key roles in plants, maintaining strict protein quality control and degrading specific sets of proteins in response to diverse environmental and developmental stimuli. Similarities and differences between the proteases expressed in different species may give valuable insights into their physiological roles and evolution. Results We have performed a comparative analysis of protease genes in the two sequenced dicot genomes, Arabidopsis thaliana and Populus trichocarpa by using genes coding for proteases in the MEROPS database 1 for Arabidopsis to identify homologous sequences in Populus. A multigene-based phylogenetic analysis was performed. Most protease families were found to be larger in Populus than in Arabidopsis, reflecting recent genome duplication. Detailed studies on e.g. the DegP, Clp, FtsH, Lon, rhomboid and papain-Like protease families showed the pattern of gene family expansion and gene loss was complex. We finally show that different Populus tissues express unique suites of protease genes and that the mRNA levels of different classes of proteases change along a developmental gradient. Conclusion Recent gene family expansion and contractions have made the Arabidopsis and Populus complements of proteases different and this, together with expression patterns, gives indications about the roles of the individual gene products or groups of proteases.

  18. Arabidopsis CDS blastp result: AK241402 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241402 J065159A02 At4g19070.1 68417.m02810 cadmium-responsive protein / cadmium i...nduced protein (AS8) identical to cadmium induced protein AS8 SP:P42735 from [Arabidopsis thaliana] 3e-11 ...

  19. Arabidopsis CDS blastp result: AK242143 [KOME

    Lifescience Database Archive (English)

    Full Text Available ar to GI:6573119 from [Lycopersicon esculentum] (Plant Physiol. 122 (1), 292 (2000)) 3e-12 ... ... identical to SP|Q9C888 Phospholipase D epsilon (EC 3.1.4.4) (AtPLDepsilon) (PLD epsilon) (PLDalpha3) {Arabidopsis thaliana}; simil

  20. Arabidopsis CDS blastp result: AK242143 [KOME

    Lifescience Database Archive (English)

    Full Text Available ar to GI:6573119 from [Lycopersicon esculentum] (Plant Physiol. 122 (1), 292 (2000)) 6e-22 ... ... identical to SP|Q9C888 Phospholipase D epsilon (EC 3.1.4.4) (AtPLDepsilon) (PLD epsilon) (PLDalpha3) {Arabidopsis thaliana}; simil

  1. Arabidopsis CDS blastp result: AK240654 [KOME

    Lifescience Database Archive (English)

    Full Text Available ar to GI:6573119 from [Lycopersicon esculentum] (Plant Physiol. 122 (1), 292 (2000)) 1e-160 ... ... identical to SP|Q9C888 Phospholipase D epsilon (EC 3.1.4.4) (AtPLDepsilon) (PLD epsilon) (PLDalpha3) {Arabidopsis thaliana}; simil

  2. Arabidopsis CDS blastp result: AK242290 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242290 J075191E07 At4g13870.1 68417.m02148 Werner Syndrome-like exonuclease (WEX)... contains Pfam profile PF01612: 3'-5' exonuclease; identical to Werner Syndrome-like exonuclease [Arabidopsis thaliana] GP:28195109 gb:AAO33765 1e-20 ...

  3. Arabidopsis CDS blastp result: AK063585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK063585 001-118-A04 At4g13870.2 Werner Syndrome-like exonuclease (WEX) contains Pf...am profile PF01612: 3'-5' exonuclease; identical to Werner Syndrome-like exonuclease [Arabidopsis thaliana] GP:28195109 gb:AAO33765 6e-16 ...

  4. Arabidopsis CDS blastp result: AK242290 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242290 J075191E07 At4g13870.2 68417.m02149 Werner Syndrome-like exonuclease (WEX)... contains Pfam profile PF01612: 3'-5' exonuclease; identical to Werner Syndrome-like exonuclease [Arabidopsis thaliana] GP:28195109 gb:AAO33765 1e-20 ...

  5. Arabidopsis CDS blastp result: AK243230 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243230 J100044L04 At1g19850.1 68414.m02490 transcription factor MONOPTEROS (MP) /... auxin-responsive protein (IAA24) / auxin response factor 5 (ARF5) identical to transcription factor MONOPTEROS (MP/IAA24/ARF5) SP:P93024 from [Arabidopsis thaliana] 2e-65 ...

  6. Arabidopsis CDS blastp result: AK103452 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK103452 J033129I11 At1g19850.1 transcription factor MONOPTEROS (MP) / auxin-respon...sive protein (IAA24) / auxin response factor 5 (ARF5) identical to transcription factor MONOPTEROS (MP/IAA24/ARF5) SP:P93024 from [Arabidopsis thaliana] 1e-166 ...

  7. Arabidopsis CDS blastp result: AK318617 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK318617 J100090H20 At1g19850.1 68414.m02490 transcription factor MONOPTEROS (MP) /... auxin-responsive protein (IAA24) / auxin response factor 5 (ARF5) identical to transcription factor MONOPTEROS (MP/IAA24/ARF5) SP:P93024 from [Arabidopsis thaliana] 2e-63 ...

  8. Arabidopsis CDS blastp result: AK287832 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287832 J065187F20 At1g30950.1 68414.m03790 unusual floral organ (UFO ) / F-box family protein ( ... ubunit; almost identical to unusual floral organs (UFO )GI:4376159 from [Arabidopsis thaliana] Landsberg-e ...

  9. Arabidopsis CDS blastp result: AK241547 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241547 J065176G22 At1g30950.1 68414.m03790 unusual floral organ (UFO ) / F-box family protein ( ... ubunit; almost identical to unusual floral organs (UFO )GI:4376159 from [Arabidopsis thaliana] Landsberg-e ...

  10. Arabidopsis CDS blastp result: AK242616 [KOME

    Lifescience Database Archive (English)

    Full Text Available ve contains PF00481: Protein phosphatase 2C domain; identical to protein phosphatase 2C (GI:4587992) [Arabidopsis thaliana] 2e-34 ... ...AK242616 J090017C19 At2g40180.1 68415.m04941 protein phosphatase 2C, putative / PP2C, putati

  11. Arabidopsis CDS blastp result: AK242846 [KOME

    Lifescience Database Archive (English)

    Full Text Available ve contains PF00481: Protein phosphatase 2C domain; identical to protein phosphatase 2C (GI:4587992) [Arabidopsis thaliana] 9e-12 ... ...AK242846 J090071I10 At2g40180.1 68415.m04941 protein phosphatase 2C, putative / PP2C, putati

  12. Arabidopsis CDS blastp result: AK241162 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241162 J065116A05 At5g54800.1 68418.m06826 glucose-6-phosphate/phosphate translocator, putative identic...al to glucose 6 phosphate/phosphate translocator [Arabidopsis thaliana] gi|7229675|gb|AAF42936 2e-11 ...

  13. Arabidopsis CDS blastp result: AK242098 [KOME

    Lifescience Database Archive (English)

    Full Text Available ve contains PF00481: Protein phosphatase 2C domain; identical to protein phosphatase 2C (GI:4587992) [Arabidopsis thaliana] 3e-22 ... ...AK242098 J075143H11 At2g40180.1 68415.m04941 protein phosphatase 2C, putative / PP2C, putati

  14. Arabidopsis CDS blastp result: AK243041 [KOME

    Lifescience Database Archive (English)

    Full Text Available ve contains PF00481: Protein phosphatase 2C domain; identical to protein phosphatase 2C (GI:4587992) [Arabidopsis thaliana] 4e-31 ... ...AK243041 J100008G07 At2g40180.1 68415.m04941 protein phosphatase 2C, putative / PP2C, putati

  15. Arabidopsis CDS blastp result: AK243539 [KOME

    Lifescience Database Archive (English)

    Full Text Available ve contains PF00481: Protein phosphatase 2C domain; identical to protein phosphatase 2C (GI:4587992) [Arabidopsis thaliana] 6e-34 ... ...AK243539 J100078G04 At2g40180.1 68415.m04941 protein phosphatase 2C, putative / PP2C, putati

  16. Arabidopsis CDS blastp result: AK242576 [KOME

    Lifescience Database Archive (English)

    Full Text Available ve contains PF00481: Protein phosphatase 2C domain; identical to protein phosphatase 2C (GI:4587992) [Arabidopsis thaliana] 3e-22 ... ...AK242576 J090009A15 At2g40180.1 68415.m04941 protein phosphatase 2C, putative / PP2C, putati

  17. Arabidopsis CDS blastp result: AK289111 [KOME

    Lifescience Database Archive (English)

    Full Text Available ve contains PF00481: Protein phosphatase 2C domain; identical to protein phosphatase 2C (GI:4587992) [Arabidopsis thaliana] 5e-20 ... ...AK289111 J090096N14 At2g40180.1 68415.m04941 protein phosphatase 2C, putative / PP2C, putati

  18. Arabidopsis CDS blastp result: AK289248 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK289248 J100079D02 At5g54800.1 68418.m06826 glucose-6-phosphate/phosphate translocator, putative identic...al to glucose 6 phosphate/phosphate translocator [Arabidopsis thaliana] gi|7229675|gb|AAF42936 7e-19 ...

  19. Arabidopsis CDS blastp result: AK287695 [KOME

    Lifescience Database Archive (English)

    Full Text Available ve contains PF00481: Protein phosphatase 2C domain; identical to protein phosphatase 2C (GI:4587992) [Arabidopsis thaliana] 3e-81 ... ...AK287695 J065129B08 At2g40180.1 68415.m04941 protein phosphatase 2C, putative / PP2C, putati

  20. Arabidopsis CDS blastp result: AK243048 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243048 J100010D20 At1g07370.1 68414.m00786 proliferating cell nuclear ... antigen 1 (PCNA1) identi ... cal to SP|Q9M7Q7 Proliferating cellular nuclear ... antigen 1 (PCNA 1) {Arabidopsis thaliana}; nearly ... identical to SP|Q43124 Proliferating cell nuclear ... antigen (PCNA) {Brassica napus}; contains Pfam pro ...

  1. Arabidopsis CDS blastp result: AK071591 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK071591 J023105C08 At2g29570.1 proliferating cell nuclear ... antigen 2 (PCNA2) identical to SP|Q9Z ... W35 Proliferating cell nuclear ... antigen 2 (PCNA 2) {Arabidopsis thaliana}; nearly ... identical to SP|Q43124 Proliferating cell nuclear ... antigen (PCNA) {Brassica napus}; contains Pfam pro ...

  2. Arabidopsis CDS blastp result: AK243048 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243048 J100010D20 At2g29570.1 68415.m03591 proliferating cell nuclear ... antigen 2 (PCNA2) identi ... cal to SP|Q9ZW35 Proliferating cell nuclear ... antigen 2 (PCNA 2) {Arabidopsis thaliana}; nearly ... identical to SP|Q43124 Proliferating cell nuclear ... antigen (PCNA) {Brassica napus}; contains Pfam pro ...

  3. Arabidopsis CDS blastp result: AK241265 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241265 J065132C02 At3g19450.1 68416.m02466 cinnamyl-alcohol dehydrogenase (CAD ) identical to S ... 523 Cinnamyl-alcohol dehydrogenase (EC 1.1.1.195) (CAD ) [Arabidopsis thaliana] 1e-81 ...

  4. Arabidopsis CDS blastp result: AK105739 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK105739 001-202-A05 At3g19450.1 cinnamyl-alcohol dehydrogenase (CAD ) identical to SP|P48523 Cin ... namyl-alcohol dehydrogenase (EC 1.1.1.195) (CAD ) [Arabidopsis thaliana] 2e-46 ...

  5. Arabidopsis CDS blastp result: AK243022 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243022 J100001E20 At3g19450.1 68416.m02466 cinnamyl-alcohol dehydrogenase (CAD ) identical to S ... 523 Cinnamyl-alcohol dehydrogenase (EC 1.1.1.195) (CAD ) [Arabidopsis thaliana] 4e-64 ...

  6. Arabidopsis CDS blastp result: AK287708 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287708 J065132C02 At3g19450.1 68416.m02466 cinnamyl-alcohol dehydrogenase (CAD ) identical to S ... 523 Cinnamyl-alcohol dehydrogenase (EC 1.1.1.195) (CAD ) [Arabidopsis thaliana] 1e-81 ...

  7. Arabidopsis CDS blastp result: AK121261 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK121261 J023104H13 At1g55350.4 calpain-type cysteine protease family identical to calpain...-like protein GI:20268660 from [Arabidopsis thaliana]; contains Pfam profiles: PF00648 Calpain family... cysteine protease, PF01067 Calpain large subunit,domain III; identical to cDNA calpain-like protein GI:20268659 0.0 ...

  8. Arabidopsis CDS blastp result: AK100867 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100867 J023124E13 At2g29640.1 josephin family protein contains Pfam domain PF02099: Jose...phin; similar to Josephin-like protein (Swiss-Prot:O82391) [Arabidopsis thaliana] 7e-59 ...

  9. Arabidopsis CDS blastp result: AK065851 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK065851 J013041L15 At1g79010.1 NADH-ubiquinone oxidoreductase 23 kDa subunit, mitochondrial (TY ... ursor (EC 1.6.5.3) (EC 1.6.99.3) (Complex I-23KD) (CI -23KD) (Complex I- 28.5KD) (CI -28.5KD) {Arabidopsis ...

  10. Arabidopsis CDS blastp result: AK119532 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK119532 001-203-F01 At1g79010.1 NADH-ubiquinone oxidoreductase 23 kDa subunit, mitochondrial (T ... ursor (EC 1.6.5.3) (EC 1.6.99.3) (Complex I-23KD) (CI -23KD) (Complex I- 28.5KD) (CI -28.5KD) {Arabidopsis ...

  11. Arabidopsis CDS blastp result: AK243512 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243512 J100075C18 At4g16280.3 68417.m02471 flowering time ... control protein / FCA gamma (FCA) id ... entical to SP|O04425 Flowering time ... control protein FCA {Arabidopsis thaliana}; four a ...

  12. Arabidopsis CDS blastp result: AK243512 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243512 J100075C18 At4g16280.2 68417.m02470 flowering time ... control protein / FCA gamma (FCA) id ... entical to SP|O04425 Flowering time ... control protein FCA {Arabidopsis thaliana}; four a ...

  13. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-130 ...

  14. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 2e-65 ...

  15. Arabidopsis CDS blastp result: AK110534 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK110534 002-168-A07 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-114 ...

  16. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 1e-24 ...

  17. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  18. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 2e-45 ...

  19. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 3e-66 ...

  20. Arabidopsis CDS blastp result: AK069071 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK069071 J023010H01 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-167 ...

  1. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-124 ...

  2. Arabidopsis CDS blastp result: AK060286 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060286 001-006-C08 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 6e-78 ...

  3. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 0.0 ...

  4. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 2e-29 ...

  5. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 5e-25 ...

  6. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-28 ...

  7. Arabidopsis CDS blastp result: AK105393 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK105393 001-123-B04 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  8. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 8e-25 ...

  9. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 1e-126 ...

  10. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 8e-63 ...

  11. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 1e-125 ...

  12. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 0.0 ...

  13. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 2e-26 ...

  14. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 4e-47 ...

  15. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 4e-98 ...

  16. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 8e-98 ...

  17. Arabidopsis CDS blastp result: AK109812 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK109812 002-147-H02 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 5e-90 ...

  18. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 3e-31 ...

  19. Arabidopsis CDS blastp result: AK121003 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK121003 J023045B21 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-167 ...

  20. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 5e-48 ...

  1. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-45 ...

  2. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 4e-27 ...

  3. Arabidopsis CDS blastp result: AK061162 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK061162 006-209-A01 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 3e-35 ...

  4. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 4e-50 ...

  5. Arabidopsis CDS blastp result: AK066153 [KOME

    Lifescience Database Archive (English)

    Full Text Available pC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF02861: Clp amino... terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  6. Arabidopsis CDS blastp result: AK287906 [KOME

    Lifescience Database Archive (English)

    Full Text Available subunit / ClpC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF028...61: Clp amino terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  7. Arabidopsis CDS blastp result: AK069552 [KOME

    Lifescience Database Archive (English)

    Full Text Available pC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF02861: Clp amino... terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  8. Arabidopsis CDS blastp result: AK100126 [KOME

    Lifescience Database Archive (English)

    Full Text Available pC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF02861: Clp amino... terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  9. Arabidopsis CDS blastp result: AK058510 [KOME

    Lifescience Database Archive (English)

    Full Text Available lpC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF02861: Clp amin...o terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  10. Arabidopsis CDS blastp result: AK318553 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK318553 J075145A22 At4g11230.1 68417.m01819 respiratory burst ... oxidase, putative / NADPH oxidase ... , putative similar to respiratory burst ... oxidase homolog F [gi:3242456], RbohAp108 [gi:2654 ... 868] from Arabidopsis thaliana, respiratory burst ... oxidase homolog [GI:16549087] from Solanum tuberos ...

  11. Arabidopsis CDS blastp result: AK110694 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK110694 002-170-A08 At5g59560.2 sensitivity to red light reduced protein (SRR1) id...entical to sensitivity to red light reduced protein [Arabidopsis thaliana] GI:25527089; supporting cDNA gi|25527088|gb|AY127047.1| 1e-18 ...

  12. Arabidopsis CDS blastp result: AK099399 [KOME

    Lifescience Database Archive (English)

    Full Text Available 079; contains weak similarity to the SAPB protein (TR:E236624) [Arabidopsis thaliana]; similar to seven transme...AK099399 J013000O17 At3g05010.1 transmembrane protein, putative similar to GB:AAB61...mbrane domain orphan receptor (GI:4321619) [Mus musculus] contains 7 transmembrane domains; 2e-89 ...

  13. Arabidopsis CDS blastp result: AK241202 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241202 J065122B10 At3g20600.1 68416.m02607 non-race specific disease resistance protein (NDR1) ... protein (NDR1) GB:AF021346 [Arabidopsis thaliana] (Science ... 278 (5345), 1963-1965 (1997)) 2e-11 ...

  14. Arabidopsis CDS blastp result: AK240830 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240830 J065014C16 At3g12280.1 68416.m01533 retinoblastoma-related protein (RBR1) nearly identical to retin...oblastoma-related protein [Arabidopsis thaliana] GI:8777927; contains Pfam profiles: PF01858 retinoblastoma...-associated protein A domain, PF01857 retinoblastoma-associated protein B domain 0.0 ...

  15. Arabidopsis CDS blastp result: AK121431 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK121431 J023138G19 At3g12280.1 retinoblastoma-related protein (RBR1) nearly identical to retinoblastoma...-related protein [Arabidopsis thaliana] GI:8777927; contains Pfam profiles: PF01858 retinoblastoma...-associated protein A domain, PF01857 retinoblastoma-associated protein B domain 0.0 ...

  16. Arabidopsis CDS blastp result: AK064987 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK064987 J013001D03 At3g12280.1 retinoblastoma-related protein (RBR1) nearly identical to retinoblastoma...-related protein [Arabidopsis thaliana] GI:8777927; contains Pfam profiles: PF01858 retinoblastoma...-associated protein A domain, PF01857 retinoblastoma-associated protein B domain 0.0 ...

  17. Arabidopsis CDS blastp result: AK241627 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241627 J065187G05 At3g12280.1 68416.m01533 retinoblastoma-related protein (RBR1) nearly identical to retin...oblastoma-related protein [Arabidopsis thaliana] GI:8777927; contains Pfam profiles: PF01858 retinoblastoma...-associated protein A domain, PF01857 retinoblastoma-associated protein B domain 0.0 ...

  18. Arabidopsis CDS blastp result: AK241568 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241568 J065179E12 At3g56700.1 68416.m06307 male ... sterility protein, putative similar to SP|Q088 ... 91 Male ... sterility protein 2 {Arabidopsis thaliana}; contai ... ns Pfam profile PF03015: Male ... sterility protein 2e-70 ...

  19. Arabidopsis CDS blastp result: AK242888 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242888 J090079L06 At3g56700.1 68416.m06307 male ... sterility protein, putative similar to SP|Q088 ... 91 Male ... sterility protein 2 {Arabidopsis thaliana}; contai ... ns Pfam profile PF03015: Male ... sterility protein 8e-81 ...

  20. Arabidopsis CDS blastp result: AK287630 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287630 J065073I15 At5g22260.1 68418.m02593 male ... sterility 1 protein, putative (MS1) identical ... to male ... sterility 1 protein [Arabidopsis thaliana] gi|1555 ... fam profile PF00628: PHD-finger; identical to cDNA male ... sterility 1 protein (ms1 gene) GI:15554514 3e-78 ...