50 results on '"E. Miginiac"'
Search Results
2. Photomorphogenesis and phytohormones
- Author
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Y. Kraepiel, E. Miginiac, Physiologie cellulaire et moléculaire des plantes (PCMP), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
chemistry.chemical_classification ,Light Signal Transduction ,Physiology ,Mechanism (biology) ,[SDV]Life Sciences [q-bio] ,food and beverages ,Plant Science ,Biology ,chemistry.chemical_compound ,Biochemistry ,chemistry ,Auxin ,Photomorphogenesis ,Abscisic acid - Abstract
There are numerous reports of interactions between light and phytohormones. However, the exact nature of this interaction is not well understood. This article considers the possible roles played in the light signal transduction chain by four phytohormones (auxin, abscisic acid, gibberellins and cytokinins). As the involvement of phytohormones in this signalling mechanism is controversial, the major arguments in the debate are reported, including recently published results based on genetic, biochemical and physiological approaches.
- Published
- 1997
3. Effects of NO3-, NH4+ and urea nutrition on endogenous levels of IAA and four cytokinins in two epiphytic bromeliads
- Author
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B. Sotta, E. Miginiac, Gilberto Barbante Kerbauy, and Helenice Mercier
- Subjects
chemistry.chemical_classification ,Physiology ,food and beverages ,Plant Science ,Biology ,biology.organism_classification ,chemistry.chemical_compound ,chemistry ,Auxin ,Cytokinin ,Botany ,Shoot ,Urea ,Ammonium ,Tillandsia recurvata ,Isopentenyladenosine ,Zeatin - Abstract
The long-term effects of different nitrogen sources on the endogenous IAA and cytokinin levels in two bromeliad species were investigated. In nature, Vriesea philippocoburgii is a tank-forming epiphytic bromeliad which uses the tank water reservoir as a substitute for soil, whereas Tillandsia pohliana is a tankless atmospheric epiphytic species. A culture was established from seeds germinated in aseptic condictions, and the plantlets were grown for 6 months in a modified Knudson medium to which was added 8 mol m -3 of nitrogen in the form of NO 3 - NH4 + or urea. The hormonal contents of the bromeliad shoots were determined by means of high-performance liquid chromatography (HPLC), coupled to an enzyme-linked immunosorbent assay (ELISA) for indole-3-acetic acid (IAA), isopentenyladenine (iP), isopentenyladenosine ([9R]iP), zeatin (Z) and zeatin riboside ([9R]Z). Nitrogen supplied in the form of urea gave the highest values of fresh and dry weights for both species, and this was positively correlated to IAA levels. The cytokinin patterns showed that isopentenyladenosine was the predominant form for both species in all samples. However, urea induced the highest level of this riboside form and also the highest level of total cytokinins for V. philippocoburgii, while NH 4 + had the same effect on the atmospheric species. These results are discussed in terms of the different growth habits of these two species in nature. It is suggested that urea may be an important source of nitrogen often found inside the tank of V. philippocoburgii. NO 3 - treatment increased the IAA/Cks balance, mainly for V. philippocoburgii, while urea and NH 4 + shifted this ratio in favour of cytokinins, thus apparently inhibiting root development in both species.
- Published
- 1997
4. Micropropagation of Pyrus communis cultivar ‘Passe Crassane’ seedlings and cultivar ‘Williams’: factors affecting root formation in vitro and ex vitro
- Author
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E. Miginiac, Y. Arnaud, and K. Al-Maarri
- Subjects
chemistry.chemical_classification ,1-Naphthaleneacetic acid ,PEAR ,biology ,fungi ,food and beverages ,Cold storage ,Horticulture ,biology.organism_classification ,chemistry.chemical_compound ,chemistry ,Micropropagation ,Auxin ,Shoot ,Botany ,Cultivar ,Pyrus communis - Abstract
Rooting of cultivars ‘Passe Crassane’ pear seedlings and ‘Williams’, which is difficult to root by conventional propagation methods, was obtained in vitro. The best exogenous auxin for rooting was naphthalene acetic acid at 0.2 mg/l. Addition of phloroglucinol to the rooting medium did not increase the percentage of shoots forming roots. Rooting percentage in ‘Williams’ was improved with increasing number of subcultures. In vivo rooting under non-sterile conditions was induced after cold storage pretreatment for 1 month followed by immersing for 1 h in auxin solutions.
- Published
- 1994
5. Session 21 Tree physiology
- Author
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A. Blažková, B. Sotta, H. Tranvan, R. Maldiney, M. Bonnet, J. Einhorn, L. Kerhoas, E. Miginiac, Ch. J. J. Buddendorf, A. D. Boer, W. M. F. Jongen, P. Correia, M. A. Martins Loução, A. M. Gonzalez-Rodriguez, D. Morales, M. S. Jimenez, L. Hřivna, R. Richter, Z. Poulík, J. Kučera, J. čermák, M. V. Marek, J. Kalina, I. Markova, T. Schulzová, I. Marková, J. Čermák, Hardy Pfanz, Bohumir Lomský, S. Pukacka, J. J. Sauter, Z. Piskornik, A. Mareczek, M. Brzezina, M. Qamaruddin, I. Ekberg, I. Dormling, L. Norell, D. H. Clapham, S. Arnold, G. Eriksson, J. Talvinen, R. Pellinen, S. Roy, T. Eloranta, R. Julkunen-Tiitto, J. Kangasjärvi, U. Schlesinger, S. Jahnke, O. T. Vedina, S. I. Toma, A. V. Veretennikov, and S. Zajaczkowski
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Tree physiology ,Communication ,business.industry ,Plant Science ,Session (computer science) ,Horticulture ,business ,Psychology - Published
- 1994
6. Detection of membrane-bound cytokinin-binding proteins in Arabidopsis thaliana cells
- Author
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M, Brault, O, Caiveau, J, Pédron, R, Maldiney, B, Sotta, and E, Miginiac
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Isopentenyladenosine ,Adenosine ,Cytokinins ,Solubility ,Arabidopsis Proteins ,Microsomes ,Arabidopsis ,Enzyme-Linked Immunosorbent Assay ,Carrier Proteins ,Chromatography, Ion Exchange ,Sensitivity and Specificity ,Plant Proteins ,Potassium Chloride - Abstract
In order to isolate cytokinin-binding proteins (CBPs), we have developed new affinity probes constituted of a cytokinin such as zeatin riboside ([9R]Z) conjugated to a carrier protein. These probes were used for detecting CBPs in an ELISA procedure. The efficiency of the cytokinin conjugate in detecting CBPs was controlled with protein model: proteins having an affinity for cytokinin such as the monoclonal anti-[9R]Z antibodies did bind the cytokinin conjugate whereas proteins unable to bind cytokinin such as bovine serum albumin did not. Using these new affinity probes, we showed that CBPs are present in the membrane fraction of in vitro cultured Arabidopsis thaliana cells. The nature of the protein at the detected binding sites was demonstrated by submitting the microsomal proteins to a proteolytic treatment, which was found to eradicate the binding. Free biologically active cytokinins or monoclonal anti-[9R]Z antibodies inhibited the binding, thus showing the specificity of the interaction. The detected CBPs were partially solubilized from the membranes with potassium chloride, indicating their peripheral membrane location. The separation by anion exchange chromatography of solubilized microsomal proteins revealed the existence of two different CBPs. They were present at higher levels in cells during the exponential growth phase.
- Published
- 1999
7. Organ correlations affecting flowering in relation to phytohormones
- Author
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E. Miginiac and B. Sotta
- Subjects
photoperiodism ,biology ,Chenopodium ,Bud ,fungi ,food and beverages ,Plant Science ,Horticulture ,biology.organism_classification ,chemistry.chemical_compound ,chemistry ,Botany ,Gibberellin ,Zeatin ,Chenopodiaceae ,Abscisic acid ,Hormone - Abstract
The influence of different organs on flowering of photoperiod- or temperature-dependent plants and of neutral plants is described. Special attention is given to the influence of roots which generally inhibit flowering. High or low temperatures applied to the roots ofChenopodium polyspermum, a quantitative short day plant, induce flowering. Vernalizing treatment of roots ofCichorium intybus suppresses the inhibition of flowering arising from the tissues immediately underlying the terminal bud. Other plants such as coniferous trees can flower more intensively if the growth of their roots is reduced. After a short presentation of the very complex situation concerning the regulation of floweringvia the presently known hormones, the methodological limitations of our understanding of the precise hormone mechanism of flowering will be discussed. One example of an immunologica 1 approach to localize endogenous hormones inside tissues is given, using abscisic acid.
- Published
- 1985
8. Mathematical Growth Analysis of Young Terminalia superba Plants in a Controlled Environment: Comparison of Growth Rhythms of the Principal Axis and of Axillary Branches
- Author
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E. Miginiac, Pascale Maillard, M. Jacques, B. Millet, UMR Physiologie Intégrée de l'Arbre Fruitier et Forestier, Université Blaise Pascal - Clermont-Ferrand 2 (UBP), and ProdInra, Migration
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0106 biological sciences ,biology ,Ecology ,Environment controlled ,Plant Science ,[SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,[SDV.BV.BOT] Life Sciences [q-bio]/Vegetal Biology/Botanics ,Terminalia superba ,Rhythm ,Botany ,RHYTHME DE CROISSANCE ,ComputingMilieux_MISCELLANEOUS ,010606 plant biology & botany ,Principal axis theorem - Abstract
International audience
- Published
- 1989
9. ACTION OF LIGHT ON ROOTING IN VITRO AND ACCLIMATIZATION OF SEQUOIA SEMPERVIRENS TO SOIL
- Author
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E. Miginiac, N. Walker, and R. Jacques
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Horticulture ,biology ,Sequoia ,Botany ,biology.organism_classification ,Acclimatization - Published
- 1987
10. Influence des corrélations entre organes sur la croissance et le développement floral des bourgeons cotylédonaires chez leScrofularia arguta Sol
- Author
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E. Miginiac
- Subjects
food.ingredient ,food ,Vegetative reproduction ,Bud ,Apical dominance ,Axillary bud ,Botany ,Plant Science ,Horticulture ,Biology ,Cotyledon - Abstract
The importance of various correlative influences on growth and vegetative or floral development of cotyledonary buds inScrofularia arguta Sol. is shown. The terminal bud, on the one hand, inhibits growth of cotyledonary buds and, on the other hand, induces their early flowering. The cotyledon stimulates growth of its axillary bud, but has no action on its floral development. Leaves above the cotyledonary node have the same effect as the cotyledon. Finally, roots stimulate vegetative growth of cotyledonary buds and suppress floral expression, but only when apical dominance has been removed at an early stage of development. Zjistily se korelativni vlivy na vegetativni a generativni vývoj kotylarnich pupenů uScrofularia arguta Sol. Terminalni pupen na jedne straně inhibuje růst kotylarů, na druhe straně vyvolava jejich casne kveteni. Dělohy stimuluji růst svých axilarů, ale neovlivňuji nastup generativniho vývoje. Listy nad dělohami maji stejný ucinek jako dělohy. Kořeny podporuji vegetativni růst kotylarů, ale potlacuji jejich generativni vývoj v připadě, že byla apikalni dominance anulovana v casných etapach vývoje.
- Published
- 1970
11. Un gradient metabolique: Rapport scopolamine/hyoscyamine dans les feuilles du Duboisia myoporoides en fonction de leur niveau d'insertion et du stade de croissance
- Author
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E. Miginiac, Louis Cosson, and N. Cougoul
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Developmental stage ,biology ,Chemistry ,food and beverages ,Plant Science ,General Medicine ,Horticulture ,biology.organism_classification ,Biochemistry ,Botany ,Duboisia myoporoides ,Scopolamine ,medicine ,Molecular Biology ,Solanaceae ,Hyoscyamine ,medicine.drug - Abstract
Hyoscine and hyoscyamine are the main alkaloids in the Australian plant Duboisia myoporoides. The ratio of hyoscine/hyoscyamine depends both on the developmental stage of the plant and on the position of the leaves on the stem; this ratio is considered as a ‘metabolic gradient’. It is a permanent metabolic marker of a given physiological state.
- Published
- 1979
12. Croissance de jeunes Terminalia superba en conditions contrôlées
- Author
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Monique Jacques, Pascale Maillard, R. Jacques, E. Miginiac, and Revues Inra, Import
- Subjects
0106 biological sciences ,0303 health sciences ,Ramification (botany) ,Plant Science ,Biology ,biology.organism_classification ,01 natural sciences ,Terminalia superba ,03 medical and health sciences ,[SDV.SA.SF]Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry ,Botany ,[SDV.SA.SF] Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,010606 plant biology & botany - Abstract
International audience
- Published
- 1987
13. Correlative growth in young Terminalia superba in a controlled environment : Effect of the leaves on internode elongation
- Author
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M. Jacques, Pascale Maillard, E. Miginiac, ProdInra, Migration, UMR Physiologie Intégrée de l'Arbre Fruitier et Forestier, and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)
- Subjects
0106 biological sciences ,Correlative ,Combretaceae ,Environment controlled ,Tropics ,Plant Science ,Biology ,[SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Terminalia superba ,[SDV.BV.BOT] Life Sciences [q-bio]/Vegetal Biology/Botanics ,Tree (descriptive set theory) ,Botany ,Arbol ,Elongation ,computer ,ComputingMilieux_MISCELLANEOUS ,010606 plant biology & botany ,computer.programming_language - Abstract
International audience
- Published
- 1987
14. Internal levels of plant growth regulators during in vitro culture of wild cherry (Prunus avium L.)
- Author
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D. Cornu, B. Sotta, Philippe Label, E. Miginiac, and Revues Inra, Import
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0106 biological sciences ,arbre forestier ,régulateur de croissance ,0303 health sciences ,Plant growth ,cytokinine ,auxine ,culture in vitro ,MERISIER ,Plant Science ,phytohormone ,Biology ,01 natural sciences ,In vitro ,feuillu ,03 medical and health sciences ,Prunus ,substance endogène ,[SDV.SA.SF]Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry ,prunus avium ,Botany ,[SDV.SA.SF] Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,010606 plant biology & botany - Abstract
International audience
- Published
- 1989
15. Endogenous levels of abscisic acid and indole-3-acetic acid during in vitro rooting of wild cherry explants produced by micropropagation
- Author
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E. Miginiac, B. Sotta, Ph. Label, ProdInra, Migration, Unité de recherche Amélioration, Génétique et Physiologie Forestières (AGPF), and Institut National de la Recherche Agronomique (INRA)
- Subjects
0106 biological sciences ,Physiology ,[SDV]Life Sciences [q-bio] ,Endogeny ,MERISIER ,Plant Science ,Biology ,01 natural sciences ,03 medical and health sciences ,Prunus ,chemistry.chemical_compound ,Auxin ,Primordium ,Abscisic acid ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,food and beverages ,[SDV] Life Sciences [q-bio] ,Horticulture ,chemistry ,Biochemistry ,Micropropagation ,ACIDE ABSCISSIQUE ,Indole-3-acetic acid ,Agronomy and Crop Science ,010606 plant biology & botany ,Explant culture - Abstract
Levels of endogenous ABA and IAA were quantified during the first week of in vitro rooting of Wild Cherry (Prunus avium L.) using IBA in the culture medium. Hormones were measured in the apical, median and basal parts of the explants using an avidin-biotin based enzyme linked immunosorbent assay (ELISA), after a purification of the methanolic extracts by high-performance liquid chromatography (HPLC). Root primordia started to differentiate from day 5 at the basal part of the explants. ABA and IAA showed considerable changes and high levels were detected during the first week of culture. ABA levels increased transiently mainly in the apical part during root formation. Exogenous IBA was possibly transformed into IAA mainly in the basal part of the explants.
- Published
- 1989
16. Mathematical analysis and comparison of growth fluctua- tions of the aerial system of young Terminalia superba Englers et Diels (Combretaceae)
- Author
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B. Millet, E. Miginiac, Monique Jacques, Pascale Maillard, and Revues Inra, Import
- Subjects
0106 biological sciences ,Combretaceae ,biology ,[SDV.SA.SF]Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry ,Botany ,Plant Science ,[SDV.SA.SF] Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry ,biology.organism_classification ,01 natural sciences ,ComputingMilieux_MISCELLANEOUS ,[ SDV.SA.SF ] Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry ,010606 plant biology & botany ,Terminalia superba - Abstract
International audience
- Published
- 1989
17. Endogenous levels of abscisic acid, indole-3-acetic acid and benzyladenine during in vitro bud growth induction of Wild Cherry (Prunus avium L.)
- Author
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E. Miginiac, R. Maldiney, L. Sossountzov, D. Cornu, Philippe Label, Unité de recherche Amélioration, Génétique et Physiologie Forestières (AGPF), Institut National de la Recherche Agronomique (INRA), and ProdInra, Migration
- Subjects
chemistry.chemical_classification ,Physiology ,Apical dominance ,[SDV]Life Sciences [q-bio] ,MERISIER ,Plant Science ,Biology ,Molecular biology ,[SDV] Life Sciences [q-bio] ,Prunus ,Tissue culture ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Auxin ,Axillary bud ,ACIDE ABSCISSIQUE ,Indole-3-acetic acid ,Agronomy and Crop Science ,Abscisic acid ,Explant culture - Abstract
Levels of endogenous growth substances (abscisic acid: ABA; indole-3-acetic acid: IAA) and applied benzyladenine (BA) were quantified during the eight first days of in vitro propagation of Wild Cherry (Prunus avium L.). Axillary buds from the middle part of the explants started to grow at day 2, thus were released from apical dominance. Hormone levels were measured in the apical, median and basal parts of the explants using an avidin-biotin based enzyme-linked immunosorbent assay (ELISA) after a purification of the extracts by high performance liquid chromatography (HPLC). All hormones showed rapid and considerable changes during the first eight days of growth. Exogenous IBA was probably transformed into IAA mainly in the basal part of the explant, and BA penetrated quickly. ABA levels were transiently enhanced in the apical part of the explants bearing young leaves. These phenomena are discussed in connection with the axillary bud reactivation.
- Published
- 1988
18. The mitogen-activated protein kinase phosphatase PHS1 regulates flowering in Arabidopsis thaliana.
- Author
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Tang Q, Guittard-Crilat E, Maldiney R, Habricot Y, Miginiac E, Bouly JP, and Lebreton S
- Subjects
- Arabidopsis growth & development, Arabidopsis Proteins genetics, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Gene Expression Regulation, Plant, MADS Domain Proteins genetics, MADS Domain Proteins metabolism, Mutation, Photoperiod, Plants, Genetically Modified, Protein Tyrosine Phosphatases genetics, RNA Processing, Post-Transcriptional, Transcription Factors genetics, Transcription Factors metabolism, Arabidopsis physiology, Arabidopsis Proteins metabolism, Flowers physiology, Protein Tyrosine Phosphatases metabolism
- Abstract
Main Conclusion: Arabidopsis PHS1, initially known as an actor of cytoskeleton organization, is a positive regulator of flowering in the photoperiodic and autonomous pathways by modulating both CO and FLC mRNA levels. Protein phosphorylation and dephosphorylation is a major type of post-translational modification, controlling many biological processes. In Arabidopsis thaliana, five genes encoding MAPK phosphatases (MKP)-like proteins have been identified. Among them, PROPYZAMIDE HYPERSENSITIVE 1 (PHS1) encoding a dual-specificity protein tyrosine phosphatase (DsPTP) has been shown to be involved in microtubule organization, germination and ABA-regulated stomatal opening. Here, we demonstrate that PHS1 also regulates flowering under long-day and short-day conditions. Using physiological, genetic and molecular approaches, we have shown that the late flowering phenotype of the knock-out phs1-5 mutant is linked to a higher expression of FLOWERING LOCUS C (FLC). In contrast, a decline of both CONSTANS (CO) and FLOWERING LOCUS T (FT) expression is observed in the knock-out phs1-5 mutant, especially at the end of the light period under long-day conditions when the induction of flowering occurs. We show that this partial loss of sensitivity to photoperiodic induction is independent of FLC. Our results thus indicate that PHS1 plays a dual role in flowering, in the photoperiodic and autonomous pathways, by modulating both CO and FLC mRNA levels. Our work reveals a novel actor in the complex network of the flowering regulation.
- Published
- 2016
- Full Text
- View/download PDF
19. The intrinsically disordered C-terminal region of Arabidopsis thaliana TCP8 transcription factor acts both as a transactivation and self-assembly domain.
- Author
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Valsecchi I, Guittard-Crilat E, Maldiney R, Habricot Y, Lignon S, Lebrun R, Miginiac E, Ruelland E, Jeannette E, and Lebreton S
- Subjects
- Amino Acid Sequence, Amino Acids chemistry, Arabidopsis, Arabidopsis Proteins metabolism, Intrinsically Disordered Proteins metabolism, Molecular Sequence Data, Molecular Weight, Phosphorylation, Protein Binding, Protein Multimerization, Transcription Factors metabolism, Arabidopsis Proteins chemistry, Intrinsically Disordered Proteins chemistry, Protein Interaction Domains and Motifs, Transcription Factors chemistry
- Abstract
TCPs are plant specific transcription factors with non-canonical basic helix-loop-helix domains. While Arabidopsis thaliana has 24 TCPs involved in cell proliferation and differentiation, their mode of action has not been fully elucidated. Using bioinformatic tools, we demonstrate that TCP transcription factors belong to the intrinsically disordered proteins (IDP) family and that disorder is higher in class I TCPs than in class II TCPs. In particular, using bioinformatic and biochemical approaches, we have characterized TCP8, a class I TCP. TCP8 exhibits three intrinsically disordered regions (IDR) made of more than 50 consecutive residues, in which phosphorylable Ser residues are mainly clustered. Phosphorylation of Ser-211 that belongs to the central IDR was confirmed by mass spectrometry. Yeast two-hybrid assays also showed that the C-terminal IDR corresponds to a transactivation domain. Moreover, biochemical experiments demonstrated that TCP8 tends to oligomerize in dimers, trimers and higher-order multimers. Bimolecular fluorescence complementation (BiFC) experiments carried out on a truncated form of TCP8 lacking the C-terminal IDR indicated that it is effectively required for the pronounced self-assembly of TCP8. These data were reinforced by the prediction of a coiled coil domain in this IDR. The C-terminal IDR acts thus as an oligomerization domain and also a transactivation domain. Moreover, many Molecular Recognition Features (MoRFs) were predicted, indicating that TCP8 could interact with several partners to fulfill a fine regulation of transcription in response to various stimuli.
- Published
- 2013
- Full Text
- View/download PDF
20. Arabidopsis thaliana lipid phosphate phosphatase 2 is involved in abscisic acid signalling in leaves.
- Author
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Paradis S, Villasuso AL, Aguayo SS, Maldiney R, Habricot Y, Zalejski C, Machado E, Sotta B, Miginiac E, and Jeannette E
- Subjects
- Abscisic Acid pharmacology, Adaptation, Physiological genetics, Arabidopsis genetics, Arabidopsis Proteins genetics, Diacylglycerol Kinase metabolism, Down-Regulation, Droughts, Gene Expression drug effects, Genotype, Mutation, Phosphatidate Phosphatase genetics, Phosphatidic Acids metabolism, Phosphotransferases (Phosphate Group Acceptor) metabolism, Signal Transduction genetics, Stress, Physiological genetics, Water physiology, Abscisic Acid metabolism, Arabidopsis metabolism, Arabidopsis Proteins metabolism, Gene Expression Regulation, Plant drug effects, Genes, Plant, Phosphatidate Phosphatase metabolism, Plant Stomata physiology
- Abstract
Lipid phosphate phosphatases (LPPs, E.C. 3.1.3.4) catalyse the dephosphorylation of diacylglycerol pyrophosphate (DGPP) and phosphatidic acid (PA), which are secondary messengers in abscisic acid (ABA) signalling. In this study, we investigated the effect of ABA on the expression of AtLPP genes as they encode putative ABA-signalling partners. We observed that AtLPP2 expression was down-regulated by ABA and we performed experiments on Atlpp2-2, an AtLPP2 knockout mutant, to determine whether AtLPP2 was involved in ABA signalling. We observed that Atlpp2-2 plantlets contained about twice as much PA as the wild-type Col-0 and exhibited higher PA kinase (PAK) activity than Col-0 plants. In addition, we showed that ABA stimulated diacylglycerol kinase (DGK) activity independently of AtLPP2 activity but that the ABA-stimulation of PAK activity recorded in Col-0 was dependent on AtLPP2. In order to evaluate the involvement of AtLPP2 activity in guard cell function, we measured the ABA sensitivity of Atlpp2-2 stomata. The inhibition of stomatal opening was less sensitive to ABA in Atlpp2-2 than in Col-0. Watered and water-stressed plants of the two genotypes accumulated ABA to the same extent, thus leading us to consider Atlpp2-2 an ABA-signalling mutant. Taken together our observations show that AtLPP2 is a part of ABA signalling and participate to the regulation of stomatal movements., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)
- Published
- 2011
- Full Text
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21. Protein tyrosine kinases and protein tyrosine phosphatases are involved in abscisic acid-dependent processes in Arabidopsis seeds and suspension cells.
- Author
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Ghelis T, Bolbach G, Clodic G, Habricot Y, Miginiac E, Sotta B, and Jeannette E
- Subjects
- Arabidopsis cytology, Arabidopsis embryology, Arabidopsis enzymology, Electrophoresis, Gel, Two-Dimensional, Enzyme Inhibitors pharmacology, Genistein pharmacology, Hydroquinones pharmacology, Phosphorylation, Protein Tyrosine Phosphatases antagonists & inhibitors, Protein Tyrosine Phosphatases chemistry, Protein-Tyrosine Kinases antagonists & inhibitors, Protein-Tyrosine Kinases chemistry, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Tyrphostins pharmacology, Abscisic Acid metabolism, Arabidopsis metabolism, Protein Tyrosine Phosphatases metabolism, Protein-Tyrosine Kinases metabolism
- Abstract
Protein tyrosine (Tyr) phosphorylation plays a central role in many signaling pathways leading to cell growth and differentiation in animals. Tyr phosphorylated proteins have been detected in higher plants, and the roles of protein Tyr phosphatases and protein Tyr kinases in some physiological responses have been shown. We investigated the involvement of Tyr phosphorylation events in abscisic acid (ABA) signaling using a pharmacological approach. Phenylarsine oxide, a specific inhibitor of protein Tyr phosphatase activity, abolished the ABA-dependent accumulation of RAB18 (responsive to ABA 18) transcripts. Protein Tyr kinase inhibitors like genistein, tyrphostin A23, and erbstatin blocked the RAB18 expression induced by ABA in Arabidopsis (Arabidopsis thaliana). Stomatal closure induced by ABA was also inhibited by phenylarsine oxide and genistein. We studied the changes in the Tyr phosphorylation levels of proteins in Arabidopsis seeds after ABA treatment. Proteins were separated by two-dimensional gel electrophoresis, and those phosphorylated on Tyr residues were detected using an anti-phosphotyrosine antibody by western blot. Changes were detected in the Tyr phosphorylation levels of 19 proteins after ABA treatment. Genistein inhibited the ABA-dependent Tyr phosphorylation of proteins. The 19 proteins were analyzed by matrix-assisted laser-desorption ionization time-of-flight/time-of-flight mass spectrometry. Among the proteins identified were storage proteins like cruciferins, enzymes involved in the mobilization of lipid reserves like aconitase, enolase, aldolase, and a lipoprotein, and enzymes necessary for seedling development like the large subunit of Rubisco. Additionally, the identification of three putative signaling proteins, a peptidyl-prolyl isomerase, an RNA-binding protein, and a small ubiquitin-like modifier-conjugating enzyme, enlightens how Tyr phosphorylation might regulate ABA transduction pathways in plants.
- Published
- 2008
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22. The phs1-3 mutation in a putative dual-specificity protein tyrosine phosphatase gene provokes hypersensitive responses to abscisic acid in Arabidopsis thaliana.
- Author
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Quettier AL, Bertrand C, Habricot Y, Miginiac E, Agnes C, Jeannette E, and Maldiney R
- Subjects
- Arabidopsis drug effects, Arabidopsis genetics, Arabidopsis Proteins genetics, Arabidopsis Proteins metabolism, Gene Expression Regulation, Plant drug effects, Germination drug effects, Light, Mutation, Protein Tyrosine Phosphatases genetics, Protein Tyrosine Phosphatases metabolism, Signal Transduction, Abscisic Acid pharmacology, Arabidopsis enzymology, Arabidopsis Proteins physiology, Plant Growth Regulators pharmacology, Protein Tyrosine Phosphatases physiology
- Abstract
The plant hormone abscisic acid (ABA) controls numerous physiological traits: dormancy and germination of seeds, senescence and resistance to abiotic stresses. In order to get more insight into the role of protein tyrosine phosphatase (PTP) in ABA signalling, we obtained eight homozygous T-DNA insertion lines in Arabidopsis thaliana PTP genes. One mutant, named phs1-3, exhibited a strong ABA-induced inhibition of germination as only 26% of its seeds germinated after 3 days instead of 92% for the Columbia (Col-0) line. Genetic and molecular analyses of phs1-3 showed that it bears a unique T-DNA insertion in the promoter of the gene and that the mutation is recessive. PHS1 expression in the mutant is about half that of the Col-0 line. The upregulation of two ABA-induced genes (At5g06760, RAB18) and the downregulation of two ABA-repressed genes (AtCLC-A, ACL) are enhanced in the phs1-3 mutant compared with the wild-type. The 'in planta' aperture of phs1-3 stomata is reduced and the inhibition of the light-induced opening of stomata by ABA is stronger in phs1-3 leaves than in Col-0 leaves. Finally, PHS1 expression is upregulated in the presence of ABA in both phs1-3 and Col-0 but more intensively in the mutant. Thus, phs1-3 is hypersensitive to ABA. Taken together, these results show that PHS1, which encodes a dual-specificity PTP, is a negative regulator of ABA signalling.
- Published
- 2006
- Full Text
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23. Induction of abscisic acid-regulated gene expression by diacylglycerol pyrophosphate involves Ca2+ and anion currents in Arabidopsis suspension cells.
- Author
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Zalejski C, Paradis S, Maldiney R, Habricot Y, Miginiac E, Rona JP, and Jeannette E
- Subjects
- Anions metabolism, Arabidopsis cytology, Arabidopsis physiology, Arabidopsis Proteins metabolism, Calcium metabolism, Calcium Channel Blockers pharmacology, Cell Culture Techniques, Cells, Cultured, Chelating Agents pharmacology, Egtazic Acid pharmacology, Fluspirilene pharmacology, Glycerol metabolism, Membrane Potentials, Pimozide pharmacology, Signal Transduction, Abscisic Acid metabolism, Arabidopsis genetics, Arabidopsis Proteins genetics, Calcium physiology, Diphosphates metabolism, Gene Expression Regulation, Plant drug effects, Glycerol analogs & derivatives
- Abstract
Diacylglycerol pyrophosphate (DGPP) was recently shown to be a possible intermediate in abscisic acid (ABA) signaling. In this study, reverse transcription-PCR of ABA up-regulated genes was used to evaluate the ability of DGPP to trigger gene expression in Arabidopsis (Arabidopsis thaliana) suspension cells. At5g06760, LTI30, RD29A, and RAB18 were stimulated by ABA and also specifically expressed in DGPP-treated cells. Use of the Ca2+ channel blockers fluspirilene and pimozide and the Ca2+ chelator EGTA showed that Ca2+ was required for ABA induction of DGPP formation. In addition, Ca2+ participated in DGPP induction of gene expression via stimulation of anion currents. Hence, a sequence of Ca2+, DGPP, and anion currents, constituting a core of early ABA-signaling events necessary for gene expression, is proposed.
- Published
- 2006
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24. Diacylglycerol pyrophosphate is a second messenger of abscisic acid signaling in Arabidopsis thaliana suspension cells.
- Author
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Zalejski C, Zhang Z, Quettier AL, Maldiney R, Bonnet M, Brault M, Demandre C, Miginiac E, Rona JP, Sotta B, and Jeannette E
- Subjects
- Arabidopsis Proteins metabolism, Cells, Cultured, Gene Expression Regulation, Plant physiology, Phosphatidic Acids metabolism, rab GTP-Binding Proteins metabolism, Abscisic Acid metabolism, Arabidopsis metabolism, Diphosphates metabolism, Glycerol analogs & derivatives, Glycerol metabolism, Second Messenger Systems
- Abstract
In plants, the importance of phospholipid signaling in responses to environmental stresses is becoming well documented. The involvement of phospholipids in abscisic acid (ABA) responses is also established. In a previous study, we demonstrated that the stimulation of phospholipase D (PLD) activity and plasma membrane anion currents by ABA were both required for RAB18 expression in Arabidopsis thaliana suspension cells. In this study, we show that the total lipids extracted from ABA-treated cells mimic ABA in activating plasmalemma anion currents and induction of RAB18 expression. Moreover, ABA evokes within 5 min a transient 1.7-fold increase in phosphatidic acid (PA) followed by a sevenfold increase in diacylglycerol pyrophosphate (DGPP) at 20 min. PA activated plasmalemma anion currents but was incapable of triggering RAB18 expression. By contrast, DGPP mimicked ABA on anion currents and was also able to stimulate RAB18 expression. Here we show the role of DGPP as phospholipid second messenger in ABA signaling.
- Published
- 2005
- Full Text
- View/download PDF
25. Plasmalemma abscisic acid perception leads to RAB18 expression via phospholipase D activation in Arabidopsis suspension cells.
- Author
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Hallouin M, Ghelis T, Brault M, Bardat F, Cornel D, Miginiac E, Rona JP, Sotta B, and Jeannette E
- Subjects
- Arabidopsis cytology, Arabidopsis enzymology, Cell Membrane drug effects, Cells, Cultured, Enzyme Activation drug effects, Gene Expression Regulation, Enzymologic drug effects, Gene Expression Regulation, Plant drug effects, Heterotrimeric GTP-Binding Proteins metabolism, Ion Channels drug effects, Membrane Potentials drug effects, Membrane Potentials physiology, Signal Transduction drug effects, Signal Transduction physiology, Substrate Specificity, Type C Phospholipases metabolism, Abscisic Acid pharmacology, Arabidopsis genetics, Arabidopsis Proteins genetics, Cell Membrane physiology, Phospholipase D metabolism, rab GTP-Binding Proteins genetics
- Abstract
Abscisic acid (ABA) plays a key role in the control of stomatal aperture by regulating ion channel activities and water exchanges across the plasma membrane of guard cells. Changes in cytoplasmic calcium content and activation of anion and outward-rectifying K(+) channels are among the earliest cellular responses to ABA in guard cells. In Arabidopsis suspension cells, we have demonstrated that outer plasmalemma perception of ABA triggered similar early events. Furthermore, a Ca(2+) influx and the activation of anion channels are part of the ABA-signaling pathway leading to the specific expression of RAB18. Here, we determine whether phospholipases are involved in ABA-induced RAB18 expression. Phospholipase C is not implicated in this ABA pathway. Using a transphosphatidylation reaction, we show that ABA plasmalemma perception results in a transient stimulation of phospholipase D (PLD) activity, which is necessary for RAB18 expression. Further experiments showed that PLD activation was unlikely to be regulated by heterotrimeric G proteins. We also observed that ABA-dependent stimulation of PLD was necessary for the activation of plasma anion current. However, when ABA activation of plasma anion channels was inhibited, the ABA-dependent activation of PLD was unchanged. Thus, we conclude that in Arabidopsis suspension cells, ABA stimulation of PLD acts upstream from anion channels in the transduction pathway leading to RAB18 expression.
- Published
- 2002
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26. The growth of tomato (Lycopersicon esculentum Mill.) hypocotyls in the light and in darkness differentially involves auxin.
- Author
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Kraepiel Y, Agnes C, Thiery L, Maldiney R, Miginiac E, and Delarue M
- Subjects
- Cryptochromes, Flavoproteins genetics, Flavoproteins physiology, Gravitropism drug effects, Gravitropism genetics, Gravitropism physiology, Herbicides pharmacology, Hypocotyl drug effects, Hypocotyl genetics, Hypocotyl radiation effects, Indoleacetic Acids antagonists & inhibitors, Indoleacetic Acids genetics, Solanum lycopersicum drug effects, Solanum lycopersicum genetics, Solanum lycopersicum radiation effects, Mutation, Phototropism genetics, Phthalimides pharmacology, Phytochrome genetics, Phytochrome physiology, Phytochrome A, Phytochrome B, Plant Growth Regulators genetics, Plant Growth Regulators pharmacology, Plant Growth Regulators physiology, Receptors, G-Protein-Coupled, Darkness, Drosophila Proteins, Eye Proteins, Hypocotyl growth & development, Indoleacetic Acids physiology, Light, Solanum lycopersicum growth & development, Photoreceptor Cells, Photoreceptor Cells, Invertebrate, Phototropism physiology, Transcription Factors
- Abstract
Light and auxin antagonistically regulate hypocotyl elongation. We have investigated the physiological interactions of light and auxin in the control of tomato (Lycopersicon esculentum Mill.) hypocotyl elongation by studying the auxin-insensitive mutant diageotropica (dgt). The length of the hypocotyls of the dgt mutant is significantly reduced when compared to the wild type line Ailsa Craig (AC) in the dark and under red light, but not under the other light conditions tested, indicating that auxin sensitivity is involved in the elongation of hypocotyls only in these conditions. Similarly, the auxin transport inhibitor naphthylphthalamic [correction of naphtylphtalamic] acid (NPA) differentially affects elongation of dark- or light-grown hypocotyls of the MoneyMaker (MM) tomato wild type. Using different photomorphogenic mutants, we demonstrate that at least phytochrome A, phytochrome B1 and, to a much lesser extent [correction of extend], cryptochrome 1, are necessary for a switch from an auxin transport-dependent elongation of hypocotyls in the dark to an auxin transport-independent elongation in the light. Interestingly, the dgt mutant and NPA-treated seedlings exhibit a looped phenotype only under red light, indicating that the negative gravitropism of hypocotyls also differentially involves auxin in the various light conditions., (c2001 Elsevier Science Ireland Ltd. All rights reserved.)
- Published
- 2001
- Full Text
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27. Abscisic acid plasmalemma perception triggers a calcium influx essential for RAB18 gene expression in Arabidopsis thaliana suspension cells.
- Author
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Ghelis T, Dellis O, Jeannette E, Bardat F, Miginiac E, and Sotta B
- Subjects
- Arabidopsis cytology, Arabidopsis genetics, Biological Transport drug effects, Blotting, Northern, Cell Membrane metabolism, Dose-Response Relationship, Drug, Extracellular Space drug effects, Extracellular Space metabolism, Gene Expression Regulation, Plant drug effects, RNA, Plant drug effects, RNA, Plant genetics, RNA, Plant metabolism, Time Factors, Abscisic Acid pharmacology, Arabidopsis drug effects, Arabidopsis Proteins, Calcium metabolism, Cell Membrane drug effects, Plant Proteins genetics, rab GTP-Binding Proteins
- Abstract
Pretreatment of Arabidopsis thaliana suspension cells with impermeant calcium chelator EGTA inhibited the ABA-induced RAB18 gene expression. However, extracellular calcium alone, up to 10 mM, did not trigger RAB18 expression. Spectrofluorimetric extracellular Ca(2+) measurement with Fluo-3 showed a fast, within 1 min, Ca(2+) influx associated with outer plasmalemma ABA perception. In the presence of the Ca(2+) blockers Cd(2+) and Ni(2+), RAB18 expression was suppressed. Pimozide and fluspirilene inhibited Ca(2+) influx and ABA-induced RAB18 expression. Thus we demonstrated the involvement of specific Ca(2+) influx in the ABA signaling sequence leading to RAB18 expression.
- Published
- 2000
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28. Corrigendum to: abscisic acid specific expression of RAB18 involves activation of anion channels in arabidopsis thaliana suspension cells (FEBS 23703).
- Author
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Ghelis T, Dellis O, Jeannette E, Bardat F, Cornel D, Miginiac E, Rona J, and Sotta B
- Published
- 2000
- Full Text
- View/download PDF
29. Abscissic acid specific expression of RAB18 involves activation of anion channels in Arabidopsis thaliana suspension cells.
- Author
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Ghelis T, Dellis O, Jeannette E, Bardat F, Cornel D, Miginiac E, Rona JP, and Sotta B
- Subjects
- Anions, Barium Compounds pharmacology, Chlorides pharmacology, Electric Conductivity, Ion Channels antagonists & inhibitors, Patch-Clamp Techniques, Potassium Channel Blockers, Potassium Channels physiology, Signal Transduction, Tetraethylammonium pharmacology, Zinc Sulfate pharmacology, Abscisic Acid pharmacology, Arabidopsis physiology, Arabidopsis Proteins, Gene Expression drug effects, Ion Channels physiology, Plant Proteins genetics, rab GTP-Binding Proteins
- Abstract
The abscissic acid (ABA) transduction cascade following the plasmalemma perception was analyzed in intact Arabidopsis thaliana suspension cells. In response to impermeant ABA, anion currents were activated and K(+) inward rectifying currents were inhibited. Anion current activation was required for the ABA specific expression of RAB18. By contrast, specific inhibition of K(+) channels by tetraethylammonium or Ba(2+) did not affect RAB18 expression. Thus, outer plasmalemma ABA perception triggered two separated signaling pathways.
- Published
- 2000
- Full Text
- View/download PDF
30. Control of seed dormancy in Nicotiana plumbaginifolia: post-imbibition abscisic acid synthesis imposes dormancy maintenance.
- Author
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Grappin P, Bouinot D, Sotta B, Miginiac E, and Jullien M
- Subjects
- Abscisic Acid biosynthesis, Abscisic Acid genetics, Abscisic Acid pharmacology, Dose-Response Relationship, Drug, Germination physiology, Gibberellins pharmacology, Kinetics, Mutation, Plant Growth Regulators pharmacology, Pyridones pharmacology, Seeds drug effects, Seeds metabolism, Nicotiana drug effects, Nicotiana genetics, Water metabolism, Water pharmacology, Plants, Toxic, Seeds growth & development, Nicotiana physiology
- Abstract
The physiological characteristics of seed dormancy in Nicotiana plumbaginifolia Viv. are described. The level of seed dormancy is defined by the delay in seed germination (i.e the time required prior to germination) under favourable environmental conditions. A wild-type line shows a clear primary dormancy, which is suppressed by afterripening, whereas an abscisic acid (ABA)-deficient mutant shows a non-dormant phenotype. We have investigated the role of ABA and gibberellic acid (GA(3)) in the control of dormancy maintenance or breakage during imbibition in suitable conditions. It was found that fluridone, a carotenoid biosynthesis inhibitor, is almost as efficient as GA(3) in breaking dormancy. Dry dormant seeds contained more ABA than dry afterripened seeds and, during early imbibition, there was an accumulation of ABA in dormant seeds, but not in afterripened seeds. In addition, fluridone and exogenous GA(3) inhibited the accumulation of ABA in imbibed dormant seeds. This reveals an important role for ABA synthesis in dormancy maintenance in imbibed seeds.
- Published
- 2000
- Full Text
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31. Induction of RAB18 gene expression and activation of K+ outward rectifying channels depend on an extracellular perception of ABA in Arabidopsis thaliana suspension cells.
- Author
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Jeannette E, Rona JP, Bardat F, Cornel D, Sotta B, and Miginiac E
- Subjects
- Abscisic Acid chemistry, Abscisic Acid metabolism, Animals, Arabidopsis metabolism, Cattle, Gene Expression Regulation, Plant drug effects, Genes, Plant, Hydrogen-Ion Concentration, Serum Albumin, Bovine, Stereoisomerism, Abscisic Acid pharmacology, Arabidopsis drug effects, Arabidopsis genetics, Arabidopsis Proteins, Plant Proteins genetics, Potassium Channels drug effects, rab GTP-Binding Proteins
- Abstract
Important progress has been made regarding the characterization of the ABA signalling components using genetic and molecular approaches (Leung and Giraudat, 1998). However, we do not yet know the mechanism of ABA perception. Conflicting results concerning the site of ABA perception have been published. The prevailing view is that since ABA controls many responses, different sites of perception for ABA might exist. In order to establish the cellular localisation of the ABA receptors in Arabidopsis thaliana suspension cells, we developed two physiological tests based upon the capacity of impermeant ABA-BSA conjugate to mimic permeant free ABA effects. We show that purified ABA-BSA conjugate is able to trigger RAB18 gene expression and that this response is strictly due to the natural (+)-ABA enantiomer. The rate of RAB18 gene expression was independent of the level of ABA uptake by the cells. Using the voltage-clamp technique we show that ABA-BSA, similarly to ABA, evokes a membrane depolarization and activates time- and voltage-dependent outward rectifying currents (ORC). We demonstrate that these ORC are due to a K+ efflux as assessed by tail currents and specific inhibition by both tetraethylammonium (TEA) and Ba2+. These observations provide evidence in favour of an extracellular site for ABA perception.
- Published
- 1999
- Full Text
- View/download PDF
32. Detection of membrane-bound cytokinin-binding proteins in Arabidopsis thaliana cells.
- Author
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Brault M, Caiveau O, Pédron J, Maldiney R, Sotta B, and Miginiac E
- Subjects
- Adenosine analogs & derivatives, Adenosine metabolism, Carrier Proteins metabolism, Chromatography, Ion Exchange, Isopentenyladenosine analogs & derivatives, Isopentenyladenosine metabolism, Microsomes chemistry, Potassium Chloride, Sensitivity and Specificity, Solubility, Arabidopsis chemistry, Arabidopsis Proteins, Carrier Proteins analysis, Cytokinins metabolism, Enzyme-Linked Immunosorbent Assay methods, Plant Proteins
- Abstract
In order to isolate cytokinin-binding proteins (CBPs), we have developed new affinity probes constituted of a cytokinin such as zeatin riboside ([9R]Z) conjugated to a carrier protein. These probes were used for detecting CBPs in an ELISA procedure. The efficiency of the cytokinin conjugate in detecting CBPs was controlled with protein model: proteins having an affinity for cytokinin such as the monoclonal anti-[9R]Z antibodies did bind the cytokinin conjugate whereas proteins unable to bind cytokinin such as bovine serum albumin did not. Using these new affinity probes, we showed that CBPs are present in the membrane fraction of in vitro cultured Arabidopsis thaliana cells. The nature of the protein at the detected binding sites was demonstrated by submitting the microsomal proteins to a proteolytic treatment, which was found to eradicate the binding. Free biologically active cytokinins or monoclonal anti-[9R]Z antibodies inhibited the binding, thus showing the specificity of the interaction. The detected CBPs were partially solubilized from the membranes with potassium chloride, indicating their peripheral membrane location. The separation by anion exchange chromatography of solubilized microsomal proteins revealed the existence of two different CBPs. They were present at higher levels in cells during the exponential growth phase.
- Published
- 1999
- Full Text
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33. Detection of abscisic-acid-binding proteins in the microsomal protein fraction of Arabidopsis thaliana with abscisic-acid-protein conjugates used as affinity probes.
- Author
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Pedron J, Brault M, Nake C, and Miginiac E
- Subjects
- Antibodies, Monoclonal, Binding, Competitive, Carrier Proteins isolation & purification, Cell Line, Cell Membrane metabolism, Enzyme-Linked Immunosorbent Assay, Ovalbumin, Plant Proteins isolation & purification, Serum Albumin, Bovine, Abscisic Acid metabolism, Arabidopsis metabolism, Carrier Proteins analysis, Microsomes metabolism, Plant Proteins analysis
- Abstract
A family of affinity probes has been generated to detect and purify abscisic-acid (ABA)-binding proteins, by coupling ABA onto carrier proteins (ovalbumin or BSA) through the C1 carboxyl group or the C4' carbonyl group of ABA. ELISA detection showed that these ABA-protein conjugates bound efficiently to the solubilized microsomal protein fraction of Arabidopsis thaliana, but not to the soluble protein fraction. Heat or proteolytic treatments inhibited the binding of the conjugates, indicating the protein nature of these binding sites. After membrane purification of the microsomes, the binding sites were found to be preferentially located in the plasma membrane fraction. The binding of the conjugates was independent of the nature of the carrier protein or the ABA-carrier protein linker, but was competitively inhibited with an anti-ABA mAb. Furthermore, the competitive inhibition of the binding of the conjugates with ABA, but not with the inactive ABA methyl ester analog, demonstrated the specificity of the binding and the saturability of the binding sites. The binding of the conjugates was strictly correlated to the ABA/carrier protein molar coupling ratio, confirming that the affinity of the conjugates to the ABA-binding proteins was enhanced by the increase in the probability of binding events. The experimental approach permits a new insight into the nature of membrane-associated ABA-binding proteins.
- Published
- 1998
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34. Germination-specific lipid transfer protein cDNAs in Brassica napus L.
- Author
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Soufleri IA, Vergnolle C, Miginiac E, and Kader JC
- Subjects
- Amino Acid Sequence, Antigens, Plant, Base Sequence, Brassica genetics, Cotyledon metabolism, DNA, Complementary, DNA, Plant, Gene Expression, Germination, Molecular Sequence Data, Plant Proteins, Sequence Homology, Amino Acid, Brassica metabolism, Carrier Proteins genetics
- Abstract
Three cDNA clones encoding lipid transfer proteins (LTPs) were isolated by applying the rapid amplification of cDNA ends (RACE) protocol to imbibed seeds and germinating seedlings Brassica napus. The deduced amino-acid sequences show a great degree of homology and they exhibit the common features shared by all LTPs. Their expression pattern indicates a strong developmental, hormonal, and environmental regulation. They are expressed only in cotyledons and hypocotyls of germinating seedlings and their levels of expression increase upon treatment with cis-abscisic acid and NaCl. Their distribution in the cotyledons of young seedlings is suggestive of a role related to the mobilization of lipid reserves.
- Published
- 1996
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35. T L -DNA transformation decreases ABA level.
- Author
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Julliard J, Pelèse F, Sotta B, Maldiney R, Primard-Brisset C, Jouanin L, Pelletier G, and Miginiac E
- Abstract
The endogenous levels of ABA were measured in Agrobacterium rhizogenes A
4 Tl -DNA transformed oilseed rape (Brassica napus L. var. oleifera cv. Brutor and cv. Drakkar), cabbage (Brassica oleracea). A4 transformed tobacco (Nicotiana tabacum cv. Xanthi) and their normal counterparts, using high performance liquid chromatography and enzyme-liked immunosorbent assay. Measurements were made on different plant tissues (i. e. floral stem, terminal bud, young leaf, mature leaf, root and root tips) and ABA levels were compared in unstressed and osmotically stressed oilseed rape plants (cv. Brutor). In unstressed Plants. in each of the 5 independent transformation events studied, a significant reduction (about 65% of control) in ABA concentration was observed in all transformed plants. When subjected to an osmotic stress, TL transformed Brutor plants showed a higher ABA accumulation than untransformed plants. The change in ABA content as a consequence of TL -DNA transformation is discussed with regard to phenotype, drought resistance and adaptability.- Published
- 1993
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36. The differential effect of N(6)-benzyl-adenine and N (6)-(Δ (2)-isopentenyl)-adenine on in vitro propagation of Paeonia suffruticosa Andr. is correlated with different hormone contents.
- Author
-
Bouza L, Jacques M, Sotta B, and Miginiac E
- Abstract
N(6)-benzyl-adenine (BA) enhanced phyllogenesis and axillary bud development of Paeonia suffruticosa during in vitro culture allowing good propagation while N(6)-(Δ(2)isopentenyl)adenine (iP) did not. During the first five days of culture, the mitotic activity of BA-treated explants was higher than in the iP-treated ones. High BA levels were detected in the BA-treated explants, and this was correlated with the absence of or the low indole-3-acetic acid (IAA) content. The low iP levels measured in iP-treated explants were correlated with high endogenous IAA content; the new cytokinin / auxin ratio could explain the lack of axillary buds and the development of only one leaf. Abscisic acid (ABA) was detected neither in the controls nor in the cytokinin-treated explants during the first week. However, intensive restoration of ABA accumulation was observed in controls from the third week onwards. Both BA and iP-treated explants accumulated less ABA than the controls but this hormone appeared later in the BA-treated explants than in the iP-treated ones.
- Published
- 1993
- Full Text
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37. Characterization of three hormone mutants of Nicotiana plumbaginifolia: evidence for a common ABA deficiency.
- Author
-
Rousselin P, Kraepiel Y, Maldiney R, Miginiac E, and Caboche M
- Abstract
Various auxin-resistant Nicotiana plumbaginifolia mutants have already been isolated, including 1217 which shows cross-resistance to paclobutrazol. Recently, a cytokinin-resistant mutant, CKR1, has been characterized and has been shown to be affected in abscisic acid (ABA) biosynthesis. We have isolated a new mutant, Esg152, which was selected on the basis of its early germination. In each of these mutants, resistance is due to a recessive nuclear mutation at a single locus. Complementation analysis indicated that mutants I217, CKR1 and Esg152 belong to the same complementation group. They have a similar phenotype, which includes a reduction in seed dormancy and an increased tendency to wilt. These mutants display an increased auxin tolerance and enhanced root formation when leaf or hypocotyl sections are cultivated on auxin. By immunoenzymatic methods, we show that the endogenous levels of ABA are significantly lower than in the wild-type. We have assigned the symbol aba1 to the recessive alleles of the locus affected in the three mutants. The complexity of hormonal interactions is discussed briefly emerging from a consideration of this class of mutants.
- Published
- 1992
- Full Text
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38. Enhancement of Naphthaleneacetic Acid-Induced Rhizogenesis in T(L)-DNA-Transformed Brassica napus without Significant Modification of Auxin Levels and Auxin Sensitivity.
- Author
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Julliard J, Sotta B, Pelletier G, and Miginiac E
- Abstract
Determination of the abscisic acid and indoleacetic acid (IAA) contents of floral stem segments of nontransformed and pRi A(4) T(L)-DNA-transformed rape (Brassica napus L. var oleifera, cv Brutor) using a high performance liquid chromatography-enzyme-linked immunosorbent assay procedure and mass spectrometry controls showed that IAA levels were not modified. The regeneration abilities of the in vitro cultured explants were compared on media supplemented with several plant growth regulator combinations. No regeneration occurred on hormone-free media, and shoot production was similar in both genotypes when supplemented with benzyladenine. In the presence of naphthaleneacetic acid (NAA), transformed explants were characterized by faster root regeneration and reduced shoot organogenesis. The optimum for root formation was the same in nontransformed and transformed plants, but the sensitivity threshold was slightly lower in the latter. The NAA inductive period was shorter (14 versus 22 h) with transformed tissue. Root neoformation occurred about 72 h earlier on transformed explants. Our results suggest mainly that there is an acceleration of the auxinic signal transduction and/or that the events preliminary to the formation of roots occur faster in the transformed tissues than in the normal ones.
- Published
- 1992
- Full Text
- View/download PDF
39. Changes in indole-3-acetic acid levels during tomato (Lycopersicon esculentum Mill.) seed development.
- Author
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Hocher V, Sotta B, Maldiney R, Bonnet M, and Miginiac E
- Abstract
The changes in the level of indole-3-acetic acid (IAA) were investigated in seeds and fruit tissues-placenta and mesocarp-during tomato (Lycopersicon esculentum Mill.) zygotic embryogenesis, which was characterized through eight morphological embryo stages [from globular (stage 1) to mature embryo (stage 8)]. In whole seeds, IAA levels increased mainly at stage 3 (young torpedo) and at stage 5 (late torpedo stage). As the seed matured and dehydrated, IAA levels decreased and showed a new distribution pattern within seed structures, preferentially in endosperm tissue. IAA contents in fruit tissues were lower but followed the same pattern as those of seeds. These data support the hypothesis of IAA biosynthesis in seeds with a transient role of the endosperm at the end of embryo development and suggest a role of IAA in fruit and seed growth. Moreover a comparison of IAA and ABA changes suggests that IAA could be especially necessary for the beginning of embryo growth, whereas ABA could act mainly at the end of the growth phase.
- Published
- 1992
- Full Text
- View/download PDF
40. Changes in abscisic acid and its β-D-glucopyranosyl ester levels during tomato (Lycopersicon esculentum Mill.) seed development.
- Author
-
Hocher V, Sotta B, Maldiney R, and Miginiac E
- Abstract
The role of abscisic acid (ABA) in tomato (Lycopersicon esculentum Mill.) zygotic embryogenesis was analysed. ABA and ABA ß-D-glucopyranosyl ester (ABA-GE) changes were determined in seeds and fruit tissues - placenta and mesocarp - during seed development, which was defined with eight embryo stages: from globular (stage 1) to mature embryo (stage 8). In whole seeds, ABA changes paralleled fresh and dry weight pattern curves and could be characterized by a high increase during embryo growth followed by a decrease as the seed matured and dehydrated. Moreover this dehydration phase led, at stage 8, to a new ABA distribution within the seed, preferentially into integument and embryo. Fruit tissue analyses provided new information about the ABA origin in seeds. ABA-GE levels were also measured and the results suggested different ABA metabolism in seed and fruit tissues.
- Published
- 1991
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41. Spatial and temporal expression of a maize lipid transfer protein gene.
- Author
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Sossountzov L, Ruiz-Avila L, Vignols F, Jolliot A, Arondel V, Tchang F, Grosbois M, Guerbette F, Miginiac E, and Delseny M
- Subjects
- Antigens, Plant, Carrier Proteins metabolism, Immunohistochemistry, Nucleic Acid Hybridization, Organ Specificity, Plant Proteins metabolism, RNA, Messenger metabolism, Seeds genetics, Seeds metabolism, Zea mays embryology, Zea mays metabolism, Carrier Proteins genetics, Gene Expression Regulation, Plant Proteins genetics, Zea mays genetics
- Abstract
We studied the temporal and spatial pattern of lipid transfer protein (LTP) gene expression, as well as the localization of this protein, in maize. Using an LTP gene, we observed an accumulation of LTP mRNA in embryos and endosperms during seed maturation. LTP gene expression was also investigated in young seedlings. After germination, the level of LTP mRNA in the coleoptile increased, with a maximum at 7 days, whereas LTP mRNA levels were low in the scutellum and negligible in roots. The high levels of LTP mRNA found in coleoptiles and embryos were confirmed by in situ hybridization. Moreover, LTP gene expression appeared to be localized in the external cellular layers and around the leaf veins. Using immunogold methods, we also observed that LTP was distributed heterogeneously in the different cells of coleoptiles and leaves. The highest concentrations of LTP were found in the outer epidermis of the coleoptiles as well as the leaf veins. Together, our observations indicate that LTP gene expression is not only organ specific and time specific but also cell specific.
- Published
- 1991
- Full Text
- View/download PDF
42. DNA synthesis in excised tobacco leaves after bromodeoxyuridine incorporation: immunohistochemical detection in semi-thin spurr sections.
- Author
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Stroobants C, Sossountzov L, and Miginiac E
- Subjects
- Histological Techniques, Interphase, Sensitivity and Specificity, Nicotiana cytology, Bromodeoxyuridine metabolism, DNA biosynthesis, Immunohistochemistry methods, Plants, Toxic, Nicotiana metabolism
- Abstract
We describe a method for localizing replicating cells in detached tobacco leaves allowed to root. The proposed protocol has shown that formalin fixation and Spurr embedding of petiole bases can be used for demonstrating DNA synthesis after bromodeoxyuridine (BrdU) incorporation. The incorporated BrdU was immunologically visualized. After resin removal, different procedures of DNA denaturation and protease digestion were tested. Combined hydrolysis with 4 N HCl for 10 min at room temperature and digestion with 0.4% pepsin for 15 min at 37 degrees C led to the best reproducible results, with either the peroxidase or the gold detection system. The method is rapid and sensitive, with precise resolution. It can be used at the light and electron microscopic levels. Its potential application is to elucidate in the same organ the role of cytokinins, a class of plant growth regulators, in dividing cells and to define the chronology of their biosynthesis in roots in relation to DNA synthesis.
- Published
- 1990
- Full Text
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43. Hormones and Pod Development in Oilseed Rape (Brassica napus).
- Author
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de Bouille P, Sotta B, Miginiac E, and Merrien A
- Abstract
The endogenous levels of several plant growth substances (indole acetic acid, IAA; abscisic acid, ABA; zeatin, Z; zeatin riboside, [9R]Z; isopentenyladenine, iP; and isopentenyladenosine, [9R]iP were measured during pod development of field grown oilseed Rape (Brassica napus L. var oleifera cv Bienvenu) with high performance liquid chromatography and immunoenzymic (enzyme-linked immunosorbent assay, ELISA) techniques. Results show that pod development is characterized by high levels of Z and [9R]Z in 3 day old fruits and of IAA on the fourth day. During pod maturation, initially a significant increase of IAA and cytokinins was observed, followed by a progressive rise of ABA levels and a concomitant decline of IAA and cytokinin (except iP) levels. The relationship between hormone levels and development, especially pod number, seed number per pod, and seed weight determination, will be discussed.
- Published
- 1989
- Full Text
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44. Comparative quantitation of abscisic acid in plant extracts by gas-liquid chromatography and an enzyme-linked immunosorbent assay using the avidin-biotin system.
- Author
-
Leroux B, Maldiney R, Miginiac E, Sossountzov L, and Sotta B
- Abstract
In this report we describe an enzyme-linked immunosorbent assay (ELISA) for the quantitation of abscisic acid (ABA) in plant extracts. A microtitration plate is coated with an ABA-protein complex. The ABA, standard or sample, is then added to each well with a limiting quantity of rabbit anti-ABA antibodies. During the following incubation period, antibodies bind either to free or to bound ABA on the plates. After washing, bound antibodies are indirectly labelled in two steps by the means of biotinylated goat antirabbit immunoglobulin-G antibodies which act as a link between rabbit anti-ABA antibodies and an avidin-alkaline phosphatase complex. The relative enzyme activity bound is measured spectrophotometrically. The detection limit of this method is 5 pg ABA and the measuring range extends to 10 ng. Gas-liquid-chromatography controls, with an electron capture detector, show a good correlation with ELISA results obtained using extracts of Lycopersicon esculentum, Nicotiana tabacum and Pseudotsuga menziesii samples purified by high-performance liquid chromatography. This provides a good argument for the accuracy of the immunoenzymatic method. The indirect labelling of antibodies, with the avidin-biotin amplifying system, should make this technique suitable for the quantitation of other plant growth substances against which specific antibodies are available.
- Published
- 1985
- Full Text
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45. Immunocytochemical localization of cytokinins in Craigella tomato and a sideshootless mutant.
- Author
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Sossountzov L, Maddiney R, Sotta B, Sabbagh I, Habricot Y, Bonnet M, and Miginiac E
- Abstract
Post-embedding immunocytochemical techniques using peroxidase-antiperoxidase or immunoglobulin G-gold as markers were used for the localization of cytokinins (CKs) in two isogenic lines, Craigella (C) and Craigella lateral suppressor (Cls), of tomato Lycopersicon esculentum Mill. Terminal buds, nodes, hypocotyl segments and root tips were submitted to a periodate-borohydride procedure, to obtain the coupling of isopentenyladeosine and zeatin riboside to cellular proteins, followed by a fixative step with a paraformaldehyde and glutaraldehyde mixture. Enzyme-linked immunosorbent assay tests performed on ovalbumin-coated microtitration plates have shown that this method was effective for CK riboside and base coupling to proteins. Paraffin-wax- or Spurr's-resin-embedded sections were cleared of wax or resin before incubation with anti-zeatin riboside or anti-isopentenyladenosine antibodies. The procedure was thoroughly investigated and many controls were done in order to eliminate artefacts. The immunostaining patterns observed along the plants showed a basipetally decreasing gradient of CKs along the stem and in the roots. Immunolabelling was higher in the actively growing regions of the stem bud and root apices. Terminal buds of Cls appeared to be less immunoreactive than C, whereas no differences were detected in root-tip immunolabelling. The staining patterns are consistent with the idea that root and bud apices have a different CK metabolism. The absence of axillary bud formation in Cls is correlated with low CK levels in the organogensis sites.
- Published
- 1988
- Full Text
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46. Abscissic acid localization by light microscopic immunohistochemistry in Chenopodium polyspermum L. Effect of water stress.
- Author
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Sotta B, Sossountzov L, Maldiney R, Sabbagh I, Tachon P, and Miginiac E
- Subjects
- Fixatives, Histocytochemistry, Immunochemistry, Immunoenzyme Techniques, Plants, Medicinal drug effects, Abscisic Acid analysis, Cyclohexanecarboxylic Acids analysis, Plants, Medicinal analysis, Water pharmacology
- Abstract
An indirect immunohistochemical technique was developed using a rabbit anti-abscissic acid (ABA) serum and the soluble peroxidase-antiperoxidase (PAP) complex for the localization of endogenous ABA in the aerial parts of Chenopodium. Terminal bud, axillary bud bearing nodes, and adult leaves were prefixed by a soluble carbodiimide to obtain the coupling of ABA on cellular proteins and postfixed by a conventional mixture of aldehydes. They were then embedded in paraffin or in plastic. Numerous controls were carried out on sections and on a model system to test the validity of the technique. Based on the staining patterns observed along the plant, an apico-basal gradient of ABA was revealed. In the older buds, ABA was mainly concentrated in the quiescent meristematic cells of the apex. Phloem cells of the main axis and chloroplasts of the leaves were specifically labeled. No reaction product was visualized in the parenchyma cells or in the cambial zone. Water stress, which is known to increase ABA content, induced an increase of immunoreactivity within the same compartments. This physiological test validates the stain.
- Published
- 1985
- Full Text
- View/download PDF
47. Nonstomatal Inhibition of Net CO(2) Uptake by (+/-) Abscisic Acid in Pharbitis nil.
- Author
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Cornic G and Miginiac E
- Abstract
(+/-) Abscisic acid (ABA) injected into petioles of attached transpiring leaves of Pharbitis nil Chois. cv violet reduced the photosynthetic capacity of the mesophyll of these leaves as well as the stomatal conductance to CO(2) diffusion. Greater than 75% of the injected ABA was recovered as ABA, suggesting that ABA rather than some metabolite thereof was the active compound. The nonstomatal effect of ABA increased from 30% reduction in photosynthesis at 0.25 micromolar ABA in the leaf blade to 90% reduction at 18 micromolar. Despite the effect of ABA on the nonstomatal component of leaf net CO(2) uptake, it was calculated that a substantial part of the reduction in leaf net CO(2) uptake (50-80%) could be accounted for by the effect of ABA on stomatal conductance.
- Published
- 1983
- Full Text
- View/download PDF
48. Immunoelectron-microscopy localization of abscisic acid with colloidal gold on Lowicryl-embedded tissues of Chnopodium polyspermum L.
- Author
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Sossountzov L, Sotta B, Maldiney R, Sabbagh I, and Miginiac E
- Abstract
Further study on the localization of abscisic acid (ABA) has been undertaken at the ultrastructural level in Chenopodium polyspermum L. Axillary-bud-bearing nodes on the main axis were fixed with soluble 1-(3-dimethylaminopropyl)-3 ethyl carbodiimide, then postfixed with paraformaldehyde and embedded in Lowicryl K4M at-20° C. Ultrathin sections mounted on grids were successively incubated with rabbit anti-ABA antibodies and with gold-labelled goat anti-rabbit anti-bodies (40 nm particle size). Control sections treated with preimmune rabbit serum and ABA-preabsorbed antibodies were devoid of label. The background staining was very low with this technique. Quantitative analysis of the immunolabelling showed that two main sites of ABA accumulation could be defined: first, plastids in cortical cells and vascular parenchyma cells associated with sieve elements and xylem vessels; second, the cell cytoplasm and nucleus in the axillary bud tip and in procambial strands. In vascular bundles, the cambial cells showed no immunoreactivity. These observations support the hypothesis for the cytoplasmic synthesis of ABA which is subsequently trapped in plastids as cells mature.
- Published
- 1986
- Full Text
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49. Hormone Levels and Apical Dominance in the Aquatic Fern Marsilea drummondii A. Br.
- Author
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Pilate G, Sossountzov L, and Miginiac E
- Abstract
Terminal buds and successively subjacent lateral buds of the water fern, Marsilea drummondii, were examined to determine the pattern of hormone distribution in relation to apical dominance. Quantitative levels of indole-3-acetic acid (IAA), abscisic acid (ABA), zeatin and zeatin riboside (Z and ZR), and isopentenyladenosine (iPA) were determined by a solid-phase immunoassay using polycional antihormone antibodies. Enzyme-linked immunosorbent assay was used following a one-step HPLC purification procedure to obtain the free hormones. Active shoot apices contained the most IAA and Z-type cytokinins and inhibited buds the least. No significant differences in ABA levels were found leading to the conclusion that ABA did not play any role in apical dominance. The normal precedence of the most rapid outgrowth of the youngest inhibited bud as observed previously in decapitated plants was well correlated with its very high level of iPA observed in this study. The same phenomenon was observed in the median buds but with a weaker amplitude. The presence of this storage form could indicate that a bud at its entry into quiescence eventually looses the ability to hydroxylate iPA to Z-type cytokinins when it is fully inhibited. IAA and Z + ZR are concluded to be essential for lateral bud growth.
- Published
- 1989
- Full Text
- View/download PDF
50. Hormonal characterization of a nonrooting naphthalene-acetic Acid tolerant tobacco mutant by an immunoenzymic method.
- Author
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Pelese F, Megnegneau B, Sotta B, Sossountzov L, Caboche M, and Miginiac E
- Abstract
The comparative analysis of plant hormones was undertaken on a 1-naphthaleneacetic acid tolerant mutant and normal tobacco (Nicotiana tabacum cv Xanthi) plantlets. The mutant plantlet was scrubby and impaired in its root morphogenesis. Degeneration of the root meristem was studied on tissue sections; it appeared very fast (as early as the 3rd or 4th day after sowing), after which the root was further transformed into a callus. Indoleacetic acid (IAA), abscisic acid (ABA), and the isopentenyladenine (iP)- and trans-zeatin(Z)-type cytokinin levels were measured in terminal buds and root tips 13 days after sowing, by enzyme linked immunosorbent assay of high performance liquid chromatography fractions. Some differences appeared between the apical buds of the two genotypes, but the mutant tobacco differed from the wild type mainly by the presence of higher levels of IAA, ABA, and iP + isopentenyladenosine (iPA) in its small root. Thus, the IAA, ABA, and iP + iPA contents were increased by a factor of 15, 7, and 24 times, respectively, in mutant root compared to wild-type tobacco roots. Previous work has shown that the mutation impairs membrane polarization effects induced by auxin at the cell level. The present results would favor the hypothesis that the mutation has also affected the control of growth regulator accumulation in tissues.
- Published
- 1989
- Full Text
- View/download PDF
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