- Seminars - maillist.psb.ugent.be

PSB event reminder
by contact＠psb.vib-ugent.be 02 Jul '13

02 Jul '13

Calendar Name: seminars Scheduled for: Tuesday, July 2 2013, 14:00 - 15:30 Event text: Prof Masaaki Umeda & Dr Naoki Takahashi Nara Institute of Science and Technology Ikoma Nara JAPAN Details: �Cell-cycle control in Arabidopsis roots by internal and external factors� ABSTRACT Plant roots respond to various internal and external signals and adjust themselves to changes of environmental conditions. Previous studies indicate that an antagonistic interaction between auxin and cytokinin hormones determines meristem size. We found that, in Arabidopsis, cytokinins promote the transition from the mitotic cell cycle to the endocycle, a modified cell cycle in which DNA replication is repeated without mitosis and cytokinesis. The cytokinin-activated type-B response regulator up-regulates the expression of CCS52A1, which encodes an activator of an E3 ubiquitin ligase, anaphase-promoting complex/cyclosome (APC/C), thereby promoting the onset of the endocycle and restricting meristem size. Our results indicate that cytokinins directly control the cell cycle and maintain root meristem size. Under stressful conditions, however, down-regulation of mitotic activity in the meristem plays an important role to sustain the suppressive state of root growth. Recently we found that repressor-type MYB transcription factors are essential to suppress mitotic activity in DNA-damaged cells, causing cell death in the stem cell region and promoting endocycle onset in the root meristem. We shall discuss how different types of MYB transcription factors control mitotic activity, and how cyclin-dependent kinase activities are involved in the regulation under changing environmental conditions.

1 0

Seminar Prof Ron Mittler on Monday, July 15 at 11 am
by Delphine Verspeel 02 Jul '13

02 Jul '13

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 . If you do not wish to receive this information anymore, please unsubscribe from future mailings at https://maillist.psb.ugent.be/mailman/options/seminars . cid:946540515@15122008-0D1CPSBcid:946540515@15122008-0D23 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

1 0

PSB event reminder
by contact＠psb.vib-ugent.be 01 Jul '13

01 Jul '13

Calendar Name: seminars Scheduled for: Monday, July 1 2013, 14:00 - 15:30 Event text: Prof Klaas Van Wijk Department of Plant Biology Cornell University Ithaca NY USA Details: �Plastoglobules and their ABC1 Kinases in Arabidopsis thaliana� ABSTRACT Plastoglobules (PG) are plastid lipid-protein particles with a small specialized proteome and metabolome. In my talk I will provide evidence that PG function as thylakoid microdomains facilitating concentration of metabolites and proteins to accommodate metabolic channeling and higher flux rates, as well as signal transduction. We constructed a comprehensive functional model of the PG based on co-expression analysis using identified PG proteins as baits. The resulting co-expression network implicated four specific functions for the PG: i) senescence, ii) plastid biogenesis, iii) prenyl-lipid metabolism, and iv) redox/photosynthetic regulation. Among the 30 PG proteins are six proteins of the ancient ABC1 atypical kinase (ABC1K) family and their locations in the co-expression network suggested important regulatory roles. Algae and higher plants have typically more than 16 ABC1Ks members, where they localize to plastids and mitochondria. We hypothesized that targets of ABC1Ks include enzymes of prenyl-lipid metabolism as well as components of the organellar gene expression machineries. Loss of function mutants for PG-localized ABC1K1 and ABC1K3 in Arabidopsis thaliana show conditional senescence-like phenotypes, involving degradation of the PSII core and upregulation of chlorophyll degradation. The senescence-like phenotype was independent of the EXECUTER pathway and correlated with increased levels of the 1O2-derived carotenoid β-cyclocitral, a retrograde plastid signal. Metabolite and proteome analyses show that ABC1K1/3 contribute to PG function in prenyl-lipid metabolism, stress response and thylakoid remodeling, and contribute to cross-talk between the thylakoid and the Calvin cycle. Ytterberg, A.J., Peltier, J.B., and van Wijk, K.J. (2006). Protein profiling of plastoglobules in chloroplasts and chromoplasts; a surprising site for differential accumulation of metabolic enzymes. Plant Physiol 140, 984-997. Brehelin, C., Kessler, F., and van Wijk, K.J. (2007). Plastoglobules: versatile lipoprotein particles in plastids. Trends Plant Sci 12, 260-266. Lundquist, P., Poliakov, A., Bhuiyan, N.H., Zybailov, B., Sun, Q., and van Wijk, K.J. (2012a). The functional network of the Arabidopsis thaliana plastoglobule proteome based on quantitative proteomics and genome-wide co-expression analysis. Plant Physiol 58, 1172-1192. Lundquist, P.K., Davis, J.I., and van Wijk, K.J. (2012b). ABC1K atypical kinases in plants: filling the organellar kinase void. Trends Plant Sci 17, 546-555. Lundquist, P., Poliakov, A., Giacomelli, L., Friso, G., Appel, M., McQuinn, R.P., Krasnoff, S.B., Rowland, O., Ponnala, L., Sun, Q., and van Wijk, K.J. (2013). Loss of plastoglobule-localized kinases ABC1K1 and ABC1K3 leads to a conditional degreening phenotype, a modified prenyl-lipid composition and recruitment of JA biosynthesis. Plant Cell - prepublication online.

1 0

PSB event reminder
by contact＠psb.vib-ugent.be 30 Jun '13

30 Jun '13

Calendar Name: seminars Scheduled for: Tuesday, July 2 2013, 14:00 - 15:30 Event text: Prof Masaaki Umeda & Dr Naoki Takahashi Nara Institute of Science and Technology Ikoma Nara JAPAN Details: �Cell-cycle control in Arabidopsis roots by internal and external factors� ABSTRACT Plant roots respond to various internal and external signals and adjust themselves to changes of environmental conditions. Previous studies indicate that an antagonistic interaction between auxin and cytokinin hormones determines meristem size. We found that, in Arabidopsis, cytokinins promote the transition from the mitotic cell cycle to the endocycle, a modified cell cycle in which DNA replication is repeated without mitosis and cytokinesis. The cytokinin-activated type-B response regulator up-regulates the expression of CCS52A1, which encodes an activator of an E3 ubiquitin ligase, anaphase-promoting complex/cyclosome (APC/C), thereby promoting the onset of the endocycle and restricting meristem size. Our results indicate that cytokinins directly control the cell cycle and maintain root meristem size. Under stressful conditions, however, down-regulation of mitotic activity in the meristem plays an important role to sustain the suppressive state of root growth. Recently we found that repressor-type MYB transcription factors are essential to suppress mitotic activity in DNA-damaged cells, causing cell death in the stem cell region and promoting endocycle onset in the root meristem. We shall discuss how different types of MYB transcription factors control mitotic activity, and how cyclin-dependent kinase activities are involved in the regulation under changing environmental conditions.

1 0

PSB event reminder
by contact＠psb.vib-ugent.be 29 Jun '13

29 Jun '13

Calendar Name: seminars Scheduled for: Monday, July 1 2013, 14:00 - 15:30 Event text: Prof Klaas Van Wijk Department of Plant Biology Cornell University Ithaca NY USA Details: �Plastoglobules and their ABC1 Kinases in Arabidopsis thaliana� ABSTRACT Plastoglobules (PG) are plastid lipid-protein particles with a small specialized proteome and metabolome. In my talk I will provide evidence that PG function as thylakoid microdomains facilitating concentration of metabolites and proteins to accommodate metabolic channeling and higher flux rates, as well as signal transduction. We constructed a comprehensive functional model of the PG based on co-expression analysis using identified PG proteins as baits. The resulting co-expression network implicated four specific functions for the PG: i) senescence, ii) plastid biogenesis, iii) prenyl-lipid metabolism, and iv) redox/photosynthetic regulation. Among the 30 PG proteins are six proteins of the ancient ABC1 atypical kinase (ABC1K) family and their locations in the co-expression network suggested important regulatory roles. Algae and higher plants have typically more than 16 ABC1Ks members, where they localize to plastids and mitochondria. We hypothesized that targets of ABC1Ks include enzymes of prenyl-lipid metabolism as well as components of the organellar gene expression machineries. Loss of function mutants for PG-localized ABC1K1 and ABC1K3 in Arabidopsis thaliana show conditional senescence-like phenotypes, involving degradation of the PSII core and upregulation of chlorophyll degradation. The senescence-like phenotype was independent of the EXECUTER pathway and correlated with increased levels of the 1O2-derived carotenoid β-cyclocitral, a retrograde plastid signal. Metabolite and proteome analyses show that ABC1K1/3 contribute to PG function in prenyl-lipid metabolism, stress response and thylakoid remodeling, and contribute to cross-talk between the thylakoid and the Calvin cycle. Ytterberg, A.J., Peltier, J.B., and van Wijk, K.J. (2006). Protein profiling of plastoglobules in chloroplasts and chromoplasts; a surprising site for differential accumulation of metabolic enzymes. Plant Physiol 140, 984-997. Brehelin, C., Kessler, F., and van Wijk, K.J. (2007). Plastoglobules: versatile lipoprotein particles in plastids. Trends Plant Sci 12, 260-266. Lundquist, P., Poliakov, A., Bhuiyan, N.H., Zybailov, B., Sun, Q., and van Wijk, K.J. (2012a). The functional network of the Arabidopsis thaliana plastoglobule proteome based on quantitative proteomics and genome-wide co-expression analysis. Plant Physiol 58, 1172-1192. Lundquist, P.K., Davis, J.I., and van Wijk, K.J. (2012b). ABC1K atypical kinases in plants: filling the organellar kinase void. Trends Plant Sci 17, 546-555. Lundquist, P., Poliakov, A., Giacomelli, L., Friso, G., Appel, M., McQuinn, R.P., Krasnoff, S.B., Rowland, O., Ponnala, L., Sun, Q., and van Wijk, K.J. (2013). Loss of plastoglobule-localized kinases ABC1K1 and ABC1K3 leads to a conditional degreening phenotype, a modified prenyl-lipid composition and recruitment of JA biosynthesis. Plant Cell - prepublication online.

1 0

Invitation mini-symposium
by Delphine Verspeel 27 Jun '13

27 Jun '13

Dear colleague, We are pleased to invite you and your team to the mini-symposium on maize as a model system hosted at our Department on September 12 th , 2013. Dave Jackson (Cold Spring Harbor Laboratory) and Mike Muszynski (Iowa State University) agreed to be our keynote speakers and will present their latest work. Feel free to forward the attached flyer to interested colleagues . Kind regards, Dirk Inz é and Hilde Nelissen -- ================================================================== Hilde Nelissen Tel:+32 (0)9 331 35 27 fax:+32 (0)9 3313809 VIB Department of Plant Systems Biology, Ghent University Technologiepark 927, 9052 Gent, BELGIUM hinel(a)psb.vib-ugent.be http://www.psb.vib-ugent.be ==================================================================

1 0

PSB event reminder
by contact＠psb.vib-ugent.be 27 Jun '13

27 Jun '13

Calendar Name: seminars Scheduled for: Thursday, June 27 2013, 11:00 - 12:30 Event text: Dr Delphine Fleury Australian Centre for Plant Functional Genomics University of Adelaide-Waite campus Glen Osmond AUSTRALIA Details: �Genetic dissection of drought tolerance in wheat� ABSTRACT Tolerance to drought is a quantitative trait, with a complex phenotype, often confounded by plant phenology. Breeding for drought tolerance is further complicated since several types of abiotic stress, such as high temperatures, high irradiance and nutrient toxicities or deficiencies can challenge crop plants simultaneously. There are additional problems in investigating the genomics of drought tolerance in wheat: most pathways and candidates genes are unknown and progress in genomics and gene cloning had been slowed due to the size (16,000 Mb) and the complexity of the genome (hexaploid). A research program for increasing drought tolerance of wheat should tackle the problem in a multi-disciplinary approach, considering interaction between multiple stresses and plant phenology, and integrating the physiological dissection of drought tolerance traits and the genetic and genomics tools, such as quantitative trait loci (QTL), microarrays and transgenic crops. The strategy developed at the ACPFG target a specific environment and select appropriate germplasms adapted to the chosen environment based on extensive definition of the morpho-physiological and molecular mechanisms of tolerance of the parents. Traditional genetics and recent omics tools are used to create structured populations and develop models for QTL analysis and positional cloning.

1 0

PSB event reminder
by contact＠psb.vib-ugent.be 25 Jun '13

25 Jun '13

Calendar Name: seminars Scheduled for: Thursday, June 27 2013, 11:00 - 12:30 Event text: Dr Delphine Fleury Australian Centre for Plant Functional Genomics University of Adelaide-Waite campus Glen Osmond AUSTRALIA Details: �Genetic dissection of drought tolerance in wheat� ABSTRACT Tolerance to drought is a quantitative trait, with a complex phenotype, often confounded by plant phenology. Breeding for drought tolerance is further complicated since several types of abiotic stress, such as high temperatures, high irradiance and nutrient toxicities or deficiencies can challenge crop plants simultaneously. There are additional problems in investigating the genomics of drought tolerance in wheat: most pathways and candidates genes are unknown and progress in genomics and gene cloning had been slowed due to the size (16,000 Mb) and the complexity of the genome (hexaploid). A research program for increasing drought tolerance of wheat should tackle the problem in a multi-disciplinary approach, considering interaction between multiple stresses and plant phenology, and integrating the physiological dissection of drought tolerance traits and the genetic and genomics tools, such as quantitative trait loci (QTL), microarrays and transgenic crops. The strategy developed at the ACPFG target a specific environment and select appropriate germplasms adapted to the chosen environment based on extensive definition of the morpho-physiological and molecular mechanisms of tolerance of the parents. Traditional genetics and recent omics tools are used to create structured populations and develop models for QTL analysis and positional cloning.

1 0

Seminar Prof Masaaki Umeda & Dr Naoki Takahashi on Tuesday, July 2 at 2 pm
by Delphine Verspeel 21 Jun '13

21 Jun '13

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 . If you do not wish to receive this information anymore, please unsubscribe from future mailings at https://maillist.psb.ugent.be/mailman/options/seminars . cid:946540515@15122008-0D1CPSBcid:946540515@15122008-0D23 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

1 0

Seminar Prof Klaas Van Wijk on Monday, July 1 at 2 pm
by Delphine Verspeel 21 Jun '13

21 Jun '13

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 . If you do not wish to receive this information anymore, please unsubscribe from future mailings at https://maillist.psb.ugent.be/mailman/options/seminars . cid:946540515@15122008-0D1CPSBcid:946540515@15122008-0D23 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

1 0