- Seminars - maillist.psb.ugent.be

PSB event reminder
by contact＠psb.vib-ugent.be 07 Jul '10

07 Jul '10

Calendar Name: seminars Scheduled for: Wednesday, July 7 2010, 11:00 - 12:30 Event text: Dr Yusuke Jikumaru Growth Regulation Research Group Plant Science Center, RIKEN Yokohama JAPAN "Establishment of a method for comprehensive plant hormone analysis by LC-MS/MS" Details: ABSTRACT Current studies revealed that the hormonal regulations were not always independent or parallel but rather often synergistic or antagonistic. In order to better understand their interactive networks, we have developed a method for plant hormone analysis by using a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Our objective is to establish a method for quantitative analysis of as many hormones and related metabolites as possible. A difficulty in this method is mainly depending on their low concentrations in plants. Because co-migrating impurities suppress ionization of target compounds, it is necessary to establish a simple but effective purification method before analysis by LC-MS/MS. We will report our current status of hormone analysis. Auxin-related compounds we analyze are indole-3-acetic acid (IAA), indole-3-aldoxime, indole-3-acetaldehyde, indole-3-acetamide and IAA-amino acid conjugates. Cytokinins are trans-zeatin, N6-(Δ2-isopentenyl)adenine, dihydrozeatin and their 3 ribosides. Abscisic acid (ABA) and its metabolites are phaseic acid (PA), dihidro-PA, 7�-OH-ABA, neo-PA and ABA-glycosyl ester (internal standards were kindly provided by Dr. Suzanne Abrams). Gibberellins are GA1, GA4 and other 12 GAs involved in GA1 and GA4 biosynthesis and metabolism. Jasmonic acid (JA) and precursors are OPDA, OPC:8 and metabolites including JA-Ile and 12-OH-JA. Salicylic acid has been analyzed relatively easily. Brassinosteroids are still difficult to analyze for now, and we can only detect castasterone. We will report our current results of Arabidopsis dry seeds, seedlings, leaves, roots and flowers. Minimum amount of plant materials we need were depending on concentrations of hormones. Usually we need approximately 250 mg fresh weight of plant materials for general hormone analysis. We can also extend the method we established for Arabidopsis to other plants.

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PSB event reminder
by contact＠psb.vib-ugent.be 05 Jul '10

05 Jul '10

Calendar Name: seminars Scheduled for: Wednesday, July 7 2010, 11:00 - 12:30 Event text: Dr Yusuke Jikumaru Growth Regulation Research Group Plant Science Center, RIKEN Yokohama JAPAN "Establishment of a method for comprehensive plant hormone analysis by LC-MS/MS" Details: ABSTRACT Current studies revealed that the hormonal regulations were not always independent or parallel but rather often synergistic or antagonistic. In order to better understand their interactive networks, we have developed a method for plant hormone analysis by using a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Our objective is to establish a method for quantitative analysis of as many hormones and related metabolites as possible. A difficulty in this method is mainly depending on their low concentrations in plants. Because co-migrating impurities suppress ionization of target compounds, it is necessary to establish a simple but effective purification method before analysis by LC-MS/MS. We will report our current status of hormone analysis. Auxin-related compounds we analyze are indole-3-acetic acid (IAA), indole-3-aldoxime, indole-3-acetaldehyde, indole-3-acetamide and IAA-amino acid conjugates. Cytokinins are trans-zeatin, N6-(Δ2-isopentenyl)adenine, dihydrozeatin and their 3 ribosides. Abscisic acid (ABA) and its metabolites are phaseic acid (PA), dihidro-PA, 7�-OH-ABA, neo-PA and ABA-glycosyl ester (internal standards were kindly provided by Dr. Suzanne Abrams). Gibberellins are GA1, GA4 and other 12 GAs involved in GA1 and GA4 biosynthesis and metabolism. Jasmonic acid (JA) and precursors are OPDA, OPC:8 and metabolites including JA-Ile and 12-OH-JA. Salicylic acid has been analyzed relatively easily. Brassinosteroids are still difficult to analyze for now, and we can only detect castasterone. We will report our current results of Arabidopsis dry seeds, seedlings, leaves, roots and flowers. Minimum amount of plant materials we need were depending on concentrations of hormones. Usually we need approximately 250 mg fresh weight of plant materials for general hormone analysis. We can also extend the method we established for Arabidopsis to other plants.

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upcoming seminar July
by Nathalie Vanden Hautte 25 Jun '10

25 Jun '10

Dear All Enclosed you can find our upcoming seminar in July. Kind regards Nathalie ____________________________________________ Nathalie Vanden Hautte Administrative Assistant VIB, Department of Plant Systems Biology Ghent University Technologiepark 927 9052 Gent Belgium Phone: +32/9/33.13.800 Fax: +32/33.13.809 Http://www.psb.ugent.be nahau(a)psb.vib-ugent.be

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PSB event reminder
by contact＠psb.vib-ugent.be 24 Jun '10

24 Jun '10

Calendar Name: seminars Scheduled for: Thursday, June 24 2010, 11:00 - 12:30 Event text: Prof Stanislaw Karpinski Warsaw University of Life Sciences Faculty of Horticulture and Landscape Architecture Dept. of Genetics, Breading and Plant Biotechnology Warsaw POLAND Details: "Can Plants think? Light Memory, Photo-Electric Signaling and Arabidopsis from Avatar" ABSTRACT We demonstrated that absorbed photons in excess regulate acclimation and immunedefenses in Arabidopsis (1, 2). We showed that local and systemic response to excess light episode is associated with photo-electro-physiological signaling (PEPS), and changes in the nonphotochemical quenching and reactive oxygen species levels. Therefore, PEPS could be a new component of the signaling network that regulate systemic acquire acclimation (SAA). PEPS propagation speed and its electrical action potential depend on glutathione synthesis in the chloroplasts and functional APX2 that is exclusively express in the bundle sheath cells. PEPS can transduce information from photosystem II of directly stressed chloroplasts to the naive chloroplasts, which never experienced excess light episodes before. DCMU and LaCl3 treatment, and mechanical braking of a petiole vasculature of exposed leaves lead to strongly reduced systemic PEPS changes and to absence of SAA. PEPS is specific for excess of blue and red light, and red but not blue light of the similar provided energy induced both, immunodefence and light acclimation. Different light episodes are differentially memorized and the wavelength-specific cellular light memory is lasting for at least several days. Our results suggest that plants could be an �intelligent� life forms (capable to learn and memorize), and indeed leaves in the dark are able to not only �see� the light (3, 4), but also are able to differently remember its spectral composition and use this memorized information to increase their survival chances. References 1. Mateo et al. (2004). Plant Phys. 136: 2818-2830. 2. M�hlenbock et al. (2008). Plant Cell 20: 2339 - 2356. 3. Foyer, C.H. and Noctor G. (1999). Science 284: 599�601. 4. Karpinski et al. (1999). Science 284: 654�657.

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seminar Dr Yusuke Jikumaru 07/07
by Nathalie Vanden Hautte 23 Jun '10

23 Jun '10

You are receiving this e-mail because you subscribed to our seminars announcements and reminders service at https://maillist.psb.ugent.be/mailman/listinfo/seminars <https://maillist.psb.ugent.be/mailman/listinfo/seminars> . If you do not wish to receive this information anymore, please unsubscribe from future mailings at https://maillist.psb.ugent.be/mailman/options/seminars <https://maillist.psb.ugent.be/mailman/options/seminars> . VIB - Department of Plant Systems Biology Technologiepark 927 B - 9052 Gent/Zwijnaarde Phone: +32 9 33 13 800 Fax: +32 9 33 13 809 Http://www.psb.vib-ugent.be

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PSB event reminder
by contact＠psb.vib-ugent.be 22 Jun '10

22 Jun '10

Calendar Name: seminars Scheduled for: Thursday, June 24 2010, 11:00 - 12:30 Event text: Prof Stanislaw Karpinski Warsaw University of Life Sciences Faculty of Horticulture and Landscape Architecture Dept. of Genetics, Breading and Plant Biotechnology Warsaw POLAND Details: "Can Plants think? Light Memory, Photo-Electric Signaling and Arabidopsis from Avatar" ABSTRACT We demonstrated that absorbed photons in excess regulate acclimation and immunedefenses in Arabidopsis (1, 2). We showed that local and systemic response to excess light episode is associated with photo-electro-physiological signaling (PEPS), and changes in the nonphotochemical quenching and reactive oxygen species levels. Therefore, PEPS could be a new component of the signaling network that regulate systemic acquire acclimation (SAA). PEPS propagation speed and its electrical action potential depend on glutathione synthesis in the chloroplasts and functional APX2 that is exclusively express in the bundle sheath cells. PEPS can transduce information from photosystem II of directly stressed chloroplasts to the naive chloroplasts, which never experienced excess light episodes before. DCMU and LaCl3 treatment, and mechanical braking of a petiole vasculature of exposed leaves lead to strongly reduced systemic PEPS changes and to absence of SAA. PEPS is specific for excess of blue and red light, and red but not blue light of the similar provided energy induced both, immunodefence and light acclimation. Different light episodes are differentially memorized and the wavelength-specific cellular light memory is lasting for at least several days. Our results suggest that plants could be an �intelligent� life forms (capable to learn and memorize), and indeed leaves in the dark are able to not only �see� the light (3, 4), but also are able to differently remember its spectral composition and use this memorized information to increase their survival chances. References 1. Mateo et al. (2004). Plant Phys. 136: 2818-2830. 2. M�hlenbock et al. (2008). Plant Cell 20: 2339 - 2356. 3. Foyer, C.H. and Noctor G. (1999). Science 284: 599�601. 4. Karpinski et al. (1999). Science 284: 654�657.

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PSB event reminder
by contact＠psb.vib-ugent.be 18 Jun '10

18 Jun '10

Calendar Name: seminars Scheduled for: Friday, June 18 2010, 11:00 - 12:30 Event text: Atle M. Bones CMBG, Department of Biology Norwegian University of Science and Technology Trondheim NORWAY Details: "From Arabidopsis thaliana to Seminavis robusta: establishing a new diatom model system for functional genomics" ABSTRACT Starting research on Arabidopsis thaliana in the 1960�s our department has a long track record of using the #1 model in plant science. Although other plants are in use the major part of our activity is still on Arabidopsis. However, we aim to establish other model systems and I will address some questions related to the establishment of Seminavis robusta as a laboratory model system for research on diatoms. Diatoms are unicellular photosynthetic algae present in marine and fresh water down to depths to which radiation can be photosynthetically exploited. Being evolutionary successful with perhaps as many as 200 000 species diatoms are major global contributors to marine primary production and to the biological carbon pump and biogeochemical cycles. Recently, the genomes of two diatoms, Thalassiosira pseudonana and Phaeodactylum tricornutum have been sequenced (Armbrust et al. 2004; Bowler et al. 2008). These two diatoms and other algae are in use in various experiments in our department related to e.g. light acclimation and bioenergy issues. Getting culture start help from professor Wim Vyverman�s group we have set out to establish Seminavis robusta as a laboratory workhorse. Basic techniques for cultivation, extraction of molecules, mating and transformation and imaging are being established. We are also aiming to sequence the Seminavis robusta genome. This work has been started and I will briefly go through the results so far and the reasoning behind the choice of Seminavis as a model system.

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PSB event reminder
by contact＠psb.vib-ugent.be 17 Jun '10

17 Jun '10

Calendar Name: seminars Scheduled for: Thursday, June 17 2010, 11:00 - 12:30 Event text: Alain Gojon Plant Biochemistry and Molecular Physiology UMR 5004 Campus INRA/SupAgro Place Viala Montpellier FRANCE Details: "Tranceptor-mediated nitrate signalling in Arabidopsis" ABSTRACT Nitrate is not only a major nitrogen source for higher plants, but also a signal molecule governing both their physiology and development. Nitrate per se regulates the expression of several hundred genes in Arabidopsis thaliana, including those of its own acquisition and assimilation pathway. The signalling effect of nitrate is also particularly strong on root development, resulting in a high plasticity of the root system architecture in response to both spatial and temporal changes in external nitrate availability. Although the nitrate signalling pathways remain largely unknown at the molecular level, evidence is accumulating that the membrane nitrate transporter NRT1.1 (CHL1) may act as a nitrate sensor triggering transduction of the nitrate signal. NRT1.1 was first characterized as a dual-affinity influx carrier involved in root nitrate acquisition from the external medium. However, knock-out mutants for NRT1.1 (chl1 mutants) display a strongly altered regulation by nitrate of other root nitrate transporters (e.g. NRT2.1, Mu�os et al. 2004, Krouk et al. 2006) and of root growth. Defective nitrate signalling in chl1 plants cannot be explained by the loss of NRT1.1 nitrate transport activity. We showed that NRT1.1 participates in a specific nitrate signalling pathway, involving the putative transcription factor ANR1, and favouring preferential growth of lateral roots in nitrate-rich patches of the external medium (Remans et al. 2006). The actual role of NRT1.1 is to repress lateral root growth in nitrate-poor patches by preventing auxin accumulation in lateral root primordia and lateral root tips when the external nitrate concentration is low. Surprisingly, the strongest effect of NRT1.1 on auxin accumulation in lateral roots is found in the absence of nitrate. The mechanisms responsible for the control of local auxin gradients in lateral roots by NRT1.1 will be discussed, in connection with the observation that NRT1.1 may not transport only nitrate, but also auxin. Altogether, recent functional studies carried out by several groups indicate that, as evidenced for the so-called yeast transceptor proteins, NRT1.1 fulfils a dual transport/sensing role governing several responses on the plant to nitrate. Mu�os S., Cazettes C., Fizames C., Gaymard F., Tillard P., Lepetit M., Lejay L., Gojon A. 2004 Transcript profiling in the chl1-5 mutant of Arabidopsis reveals a role of the nitrate transporter NRT1.1 in the regulation of another nitrate transporter, NRT2.1. Plant Cell 16: 2433-2447. Krouk G., Tillard P., Gojon A. 2006 Regulation of the high-affinity NO3- uptake system by NRT1.1-mediated NO3- demand signaling in Arabidopsis. Plant Physiol. 142: 1075-1086. Remans T., Nacry P., Pervent M., Filleur S., Diatloff E., Mounier E., Tillard P., Forde B.G., Gojon A. 2006 The Arabidopsis NRT1.1 transporter participates in the signaling pathway triggering root colonization of nitrate-rich patches. Proc. Natl. Acad. Sci. USA 103 : 19206-19211.

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PSB event reminder
by contact＠psb.vib-ugent.be 16 Jun '10

16 Jun '10

Calendar Name: seminars Scheduled for: Friday, June 18 2010, 11:00 - 12:30 Event text: Atle M. Bones CMBG, Department of Biology Norwegian University of Science and Technology Trondheim NORWAY Details: "From Arabidopsis thaliana to Seminavis robusta: establishing a new diatom model system for functional genomics" ABSTRACT Starting research on Arabidopsis thaliana in the 1960�s our department has a long track record of using the #1 model in plant science. Although other plants are in use the major part of our activity is still on Arabidopsis. However, we aim to establish other model systems and I will address some questions related to the establishment of Seminavis robusta as a laboratory model system for research on diatoms. Diatoms are unicellular photosynthetic algae present in marine and fresh water down to depths to which radiation can be photosynthetically exploited. Being evolutionary successful with perhaps as many as 200 000 species diatoms are major global contributors to marine primary production and to the biological carbon pump and biogeochemical cycles. Recently, the genomes of two diatoms, Thalassiosira pseudonana and Phaeodactylum tricornutum have been sequenced (Armbrust et al. 2004; Bowler et al. 2008). These two diatoms and other algae are in use in various experiments in our department related to e.g. light acclimation and bioenergy issues. Getting culture start help from professor Wim Vyverman�s group we have set out to establish Seminavis robusta as a laboratory workhorse. Basic techniques for cultivation, extraction of molecules, mating and transformation and imaging are being established. We are also aiming to sequence the Seminavis robusta genome. This work has been started and I will briefly go through the results so far and the reasoning behind the choice of Seminavis as a model system.

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PSB event reminder
by contact＠psb.vib-ugent.be 15 Jun '10

15 Jun '10

Calendar Name: seminars Scheduled for: Thursday, June 17 2010, 11:00 - 12:30 Event text: Alain Gojon Plant Biochemistry and Molecular Physiology UMR 5004 Campus INRA/SupAgro Place Viala Montpellier FRANCE Details: "Tranceptor-mediated nitrate signalling in Arabidopsis" ABSTRACT Nitrate is not only a major nitrogen source for higher plants, but also a signal molecule governing both their physiology and development. Nitrate per se regulates the expression of several hundred genes in Arabidopsis thaliana, including those of its own acquisition and assimilation pathway. The signalling effect of nitrate is also particularly strong on root development, resulting in a high plasticity of the root system architecture in response to both spatial and temporal changes in external nitrate availability. Although the nitrate signalling pathways remain largely unknown at the molecular level, evidence is accumulating that the membrane nitrate transporter NRT1.1 (CHL1) may act as a nitrate sensor triggering transduction of the nitrate signal. NRT1.1 was first characterized as a dual-affinity influx carrier involved in root nitrate acquisition from the external medium. However, knock-out mutants for NRT1.1 (chl1 mutants) display a strongly altered regulation by nitrate of other root nitrate transporters (e.g. NRT2.1, Mu�os et al. 2004, Krouk et al. 2006) and of root growth. Defective nitrate signalling in chl1 plants cannot be explained by the loss of NRT1.1 nitrate transport activity. We showed that NRT1.1 participates in a specific nitrate signalling pathway, involving the putative transcription factor ANR1, and favouring preferential growth of lateral roots in nitrate-rich patches of the external medium (Remans et al. 2006). The actual role of NRT1.1 is to repress lateral root growth in nitrate-poor patches by preventing auxin accumulation in lateral root primordia and lateral root tips when the external nitrate concentration is low. Surprisingly, the strongest effect of NRT1.1 on auxin accumulation in lateral roots is found in the absence of nitrate. The mechanisms responsible for the control of local auxin gradients in lateral roots by NRT1.1 will be discussed, in connection with the observation that NRT1.1 may not transport only nitrate, but also auxin. Altogether, recent functional studies carried out by several groups indicate that, as evidenced for the so-called yeast transceptor proteins, NRT1.1 fulfils a dual transport/sensing role governing several responses on the plant to nitrate. Mu�os S., Cazettes C., Fizames C., Gaymard F., Tillard P., Lepetit M., Lejay L., Gojon A. 2004 Transcript profiling in the chl1-5 mutant of Arabidopsis reveals a role of the nitrate transporter NRT1.1 in the regulation of another nitrate transporter, NRT2.1. Plant Cell 16: 2433-2447. Krouk G., Tillard P., Gojon A. 2006 Regulation of the high-affinity NO3- uptake system by NRT1.1-mediated NO3- demand signaling in Arabidopsis. Plant Physiol. 142: 1075-1086. Remans T., Nacry P., Pervent M., Filleur S., Diatloff E., Mounier E., Tillard P., Forde B.G., Gojon A. 2006 The Arabidopsis NRT1.1 transporter participates in the signaling pathway triggering root colonization of nitrate-rich patches. Proc. Natl. Acad. Sci. USA 103 : 19206-19211.

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