Project description:In our laboratory we are interested in studying the functions of WRKY zinc finger type transcription factors. There are 74 members of this gene family in Arabidopsis. WRKY factors are key regulators of distinct plant defense responses and are involved in certain developmental programs e.g. trichome development and plant leaf senescence. We would like to determine the functions of a small sub-group (group II-a) of WRKY factors in response to bacterial infection. Our aim is to compare and contrast the gene expression profiles of 3-week-old wild type and WRKY T-DNA knockout mutants grown in a growth chamber under long day growth conditions and subsequently challenged for 6 hours with the virulent bacterial pathogen /Pseudomonas syringae/ DC3000. Experimenter name: Bekir Uelker; Experimenter phone: 49-221-5062-310; Experimenter fax: 49-221-5062-353; Experimenter department: Somsissich Lab; Experimenter institute: Max-Planck-Institute for Plant Breeding Research; Experimenter address: Department of Plant Microbe Interactions; Experimenter address: Carl-von-Linne-Weg 10; Experimenter address: Cologne; Experimenter zip/postal_code: 50829; Experimenter country: Germany Experiment Overall Design: 7 samples were used in this experiment
Project description:Leaf senescence is the final developmental process that includes the mobilization of nutrients from old leaves to newly growing tissues. The progression of leaf senescence requires dynamic but coordinated changes of gene expression. Although several transcription factors (TFs) are known to be involved in both negative and positive modes of regulation of leaf senescence, detailed mechanisms that underlie the progression of leaf senescence are largely unknown. We report here that the class II ERF transcriptional repressors are controlled by proteasome and regulate the progression of leaf senescence in Arabidopsis. Since we had previously demonstrated that NtERF3, a model of tobacco class II ERFs, specifically interacts with a ubiquitin-conjugating enzyme, we examined the stability of NtERF3 and found that bacterially produced NtERF3 was rapidly degraded by plant protein extracts in vitro. Whereas NtERF3 accumulation was low in plants, it was increased by treatment with a proteasome inhibitor. Arabidopsis class II ERFs, namely, AtERF4 and AtERF8, were also controlled by proteasome and stabilized by aging of plants. The transgenic plants in which NtERF3, AtERF4, and AtERF8 were individually expressed under the control of the 35S promoter exhibited the precocious leaf senescence. Our microarray and RT-PCR analyses revealed that AtERF4 regulated expression of genes involving in various stress responses and leaf senescence. In contrast, aterf4 aterf8 mutant exhibited delayed leaf senescence. Taken together, we present the important role of class II ERFs in the regulation of leaf senescence.
Project description:Leaf senescence is the final developmental process that includes the mobilization of nutrients from old leaves to newly growing tissues. The progression of leaf senescence requires dynamic but coordinated changes of gene expression. Although several transcription factors (TFs) are known to be involved in both negative and positive modes of regulation of leaf senescence, detailed mechanisms that underlie the progression of leaf senescence are largely unknown. We report here that the class II ERF transcriptional repressors are controlled by proteasome and regulate the progression of leaf senescence in Arabidopsis. Since we had previously demonstrated that NtERF3, a model of tobacco class II ERFs, specifically interacts with a ubiquitin-conjugating enzyme, we examined the stability of NtERF3 and found that bacterially produced NtERF3 was rapidly degraded by plant protein extracts in vitro. Whereas NtERF3 accumulation was low in plants, it was increased by treatment with a proteasome inhibitor. Arabidopsis class II ERFs, namely, AtERF4 and AtERF8, were also controlled by proteasome and stabilized by aging of plants. The transgenic plants in which NtERF3, AtERF4, and AtERF8 were individually expressed under the control of the 35S promoter exhibited the precocious leaf senescence. Our microarray and RT-PCR analyses revealed that AtERF4 regulated expression of genes involving in various stress responses and leaf senescence. In contrast, aterf4 aterf8 mutant exhibited delayed leaf senescence. Taken together, we present the important role of class II ERFs in the regulation of leaf senescence. Transcriptomes of 35S:AtERF4-HA and 35S:NLS-GFP-HA (control) Arabidopsis two-weeks seedling were compared.
Project description:In our laboratory we are interested in studying the functions of WRKY zinc finger type transcription factors. There are 74 members of this gene family in Arabidopsis. WRKY factors are key regulators of distinct plant defense responses and are involved in certain developmental programs e.g. trichome development and plant leaf senescence. We would like to determine the functions of a small sub-group (group II-a) of WRKY factors in response to bacterial infection. Our aim is to compare and contrast the gene expression profiles of 3-week-old wild type and WRKY T-DNA knockout mutants grown in a growth chamber under long day growth conditions and subsequently challenged for 6 hours with the virulent bacterial pathogen /Pseudomonas syringae/ DC3000. Experimenter name: Bekir Uelker Experimenter phone: 49-221-5062-310 Experimenter fax: 49-221-5062-353 Experimenter department: Somsissich Lab Experimenter institute: Max-Planck-Institute for Plant Breeding Research Experimenter address: Department of Plant Microbe Interactions Experimenter address: Carl-von-Linne-Weg 10 Experimenter address: Cologne Experimenter zip/postal_code: 50829 Experimenter country: Germany Keywords: genetic_modification_design
Project description:In our laboratory we are interested in studying the functions of WRKY zink finger type transcription factors. There are 74 members of this gene family in Arabidopsis. WRKY factors are key regulators of distinct plant defense responses and are involved in certain developmental programs e.g. plant senescence. We would like to determine the functions of a small sub-group (group II-a) of WRKY factors. Our aim to compare and contrast the gene expression profiles of 35 days-old untreated wild type and WRKY T-DNA knockout plants grown in a growth chamber under long day growth conditions. All plants chosen at this stage showed slight yellowing of the first two to four leaves. Experimenter name: Bekir Uelker; Experimenter phone: 49-221-5062-310; Experimenter fax: 49-221-5062-353; Experimenter department: Somsissich Lab; Experimenter institute: Max-Planck-Institute for Plant Breeding Research; Experimenter address: Department of Plant Microbe Interactions; Experimenter address: Carl-von-Linne-Weg 10; Experimenter address: Cologne; Experimenter zip/postal_code: 50829; Experimenter country: Germany Experiment Overall Design: 8 samples were used in this experiment
Project description:The experiments were performed to monitor dynamics in WRKY transcription factor abundancies upon treatment with flg22, a peptide derived from the bacterial flagella. Mock-treated or WT seedlings treated for 2 h with flg22 were used to prepare crude nuclear lysates. Then pull downs were performed with an anti-all-WRKY antiserum to enrich for WRKY transcription factor proteins prior to MS.
Project description:In our laboratory we are interested in studying the functions of WRKY zink finger type transcription factors. There are 74 members of this gene family in Arabidopsis. WRKY factors are key regulators of distinct plant defense responses and are involved in certain developmental programs e.g. plant senescence. We would like to determine the functions of a small sub-group (group II-a) of WRKY factors. Our aim to compare and contrast the gene expression profiles of 35 days-old untreated wild type and WRKY T-DNA knockout plants grown in a growth chamber under long day growth conditions. All plants chosen at this stage showed slight yellowing of the first two to four leaves. Experimenter name: Bekir Uelker Experimenter phone: 49-221-5062-310 Experimenter fax: 49-221-5062-353 Experimenter department: Somsissich Lab Experimenter institute: Max-Planck-Institute for Plant Breeding Research Experimenter address: Department of Plant Microbe Interactions Experimenter address: Carl-von-Linne-Weg 10 Experimenter address: Cologne Experimenter zip/postal_code: 50829 Experimenter country: Germany Keywords: genetic_modification_design