Although bodyguard (bdg), lacerata (lcr) and fiddlehead (fdh) mutations affect three unrelated genes, they trigger similar effects, i.e. ectopic organ fusion, increase of cuticle permeability. After performing cutin and wax analyses on these Arabidopsis thaliana mutants, which did not coincide with the putative enzyme functions, we hypothesised that these mutations trigger a complex response which may be visible at the transcriptional level.
Dissection of the complex phenotype in cuticular mutants of Arabidopsis reveals a role of SERRATE as a mediator.
Specimen part
View SamplesRecognition of microbial patterns and host derived damage signals by host pattern recognition receptors is a key step in immune activation in multicellular eukaryotes. Here we show how mutations in ethylene signaling and the coreceptor bak1 affect host immune responses triggered by elicitors.
Layered pattern receptor signaling via ethylene and endogenous elicitor peptides during Arabidopsis immunity to bacterial infection.
Treatment, Time
View SamplesInnate immune responses of plant cells confer the first line of defence against pathogens. Signals generated by activated receptors are integrated inside the cell and converge on transcriptional programmes in the nucleus. The Arabidopsis Toll-related intracellular receptor RPS4 operates inside nuclei to trigger resistance to Pseudomonas bacteria expressing AvrRps4 and defence gene reprogramming through the stress response regulator, EDS1.
Arabidopsis TNL-WRKY domain receptor RRS1 contributes to temperature-conditioned RPS4 auto-immunity.
Specimen part
View SamplesArabidopsis SnRK1 is structurally and functionally related to the yeast Snf1 and mammalian AMP-activated kinases, which are activated in response to carbon/glucose limitation and stress conditions causing an imbalance of energy homeostasis increasing the AMP/ATP ratio. Mutations of the SNF4 activating subunit of trimeric Arabidopsis SnRK1 complexes are not transmitted through the male meiosis. Silencing of SNF4 by a -estradiol-inducible artificial microRNA (amiR-SNF4) constructs was used to examine how inhibition of SnRK1 affects transcriptional regulation of different cellular pathways in dark and light grown seedlings. This study shows that amiR-SNF4 silencing of SnRK1 leads to coordinate transcriptional activation of salicylic acid and trehalose synthesis, oxidative/endoplasmic reticulum stress and pathogen defense responses by inducing simultaneous changes in numerous other essential hormonal and metabolic pathways in Arabidopsis.
No associated publication
Age, Specimen part
View SamplesSerine phosphorylation of conserved Y1S2P3T4S5P6S7 repeats of RNA polymerase II carboxy-terminal domain (RNAPII CTD) plays a central role in the regulation of transcription and co-transcriptional RNA processing. Maintenance of CTD phosphoserine-7 mark in Arabidopsis requires the CDKF;1 kinase, which mediates in vivo activation of downstream-acting CDKD CTD kinase family. Knockout mutations of CDKF;1 lead to over 50% reduction of RNAPII CTD Ser-7 phosphorylation as early as 7 days after germination in seedlings. The transcript profiling experiment aimed at determining how early changes in CTD Ser-7 phosphorylation affect global regulation of transcription.
No associated publication
Specimen part
View SamplesTIR-type nucleotide-binding leucine-rich repeat domain proteins (TNLs) constitute one major group of immune receptors in dicotyledonous plants. Under normal conditions, TNLs can detect non-self or modified-self within the plant cytoplasm to activate immune signaling characterized by extensive transcriptional reprogramming and efficiently counteracting pathogen infection. At the same time, TNLs, in negative epistatic interaction with a second endogeneous locus or allele are causal for induction of autoimmunity or hybrid necrosis. Both native, pathogen-induced TNL responses and autoimmunity are fully dependent on the plant-specific lipase-like protein EDS1, which is a central integrator for all TNL-mediated responses. EDS1 signals within structurally similar, but spatially distinct complexes with PAD4 and SAG101. We here analyzed stable transgenic lines expressing an EDS1 fusion with enforced nuclear localization. Even in absence of SAG101, nuclear-localized EDS1-PAD4 complexes are fully sufficient to function in basal and effector-triggered immunity. Furthermore, we show that nuclear EDS1, when expressed to high levels, can induce autoimmuity in combination with an RPP1-like gene cluster from ecotype Ler. RPP1-like genes are also implicated in several cases of hybrid necrosis, and we can identify the RPP1 paralog R8 as causal for autoimmunity induction by nuclear EDS1 and a previously characterized, EMS-induced mutation. This highlights the important role of EDS1-family proteins in the nuclear compartment in different immune-like responses.
Arabidopsis thaliana DM2h (R8) within the Landsberg RPP1-like Resistance Locus Underlies Three Different Cases of EDS1-Conditioned Autoimmunity.
Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Alternative generation of CNS neural stem cells and PNS derivatives from neural crest-derived peripheral stem cells.
Specimen part
View SamplesNeural crest-derived neural stem cells (NCSCs) from the embryonic PNS can be reprogrammed in neurosphere culture (NS) to rNCSCs that produce CNS progeny, including myelinating oligodendrocytes. Using global gene expression analysis we now demonstrate that rNCSCs completely lose their previous PNS characteristics and acquire the identity of neural stem cells derived from embryonic spinal cord (SCSCs). Reprogramming proceeds rapidly and results in a homogenous population of Olig2-, Sox3- and Lex-positive CNS stem cells. Low-level expression of pluripotency inducing genes Oct4, Nanog and Klf4 argues against a transient pluripotent state during reprogramming. The acquisition of CNS properties is prevented in the presence of BMP4 (BMP NCSCs) as shown by marker gene expression and the potential to produce PNS neurons and glia. In addition, genes characteristic for mesenchymal and perivascular progenitors are expressed, which suggests that BMP NCSCs are directed towards a pericyte progenitor/mesenchymal stem cell (MSC) fate. Adult NCSCs from mouse palate, an easily accessible source of adult NCSCs, display strikingly similar properties. They do not generate cells with CNS characteristics but lose the neural crest markers Sox10 and p75 and produce MSCs. These findings show that embryonic NCSCs acquire a full CNS identity in neurosphere culture. In contrast, MSCs are generated from adult pNCSCs and BMP NCSCs, which reveals that postmigratory NCSCs are a source for MSCs up to the adult stage.
Alternative generation of CNS neural stem cells and PNS derivatives from neural crest-derived peripheral stem cells.
Specimen part
View SamplesC57BL/6 male mice were fed a standardized NCD or HFD after weaning (4 weeks of age) over a course of 12 weeks.
No associated publication
Sex, Specimen part
View SamplesNeural crest-derived neural stem cells (NCSCs) from the embryonic PNS can be reprogrammed in neurosphere culture (NS) to rNCSCs that produce CNS progeny, including myelinating oligodendrocytes. Using global gene expression analysis we now demonstrate that rNCSCs completely lose their previous PNS characteristics and acquire the identity of neural stem cells derived from embryonic spinal cord (SCSCs). Reprogramming proceeds rapidly and results in a homogenous population of Olig2-, Sox3- and Lex-positive CNS stem cells. Low-level expression of pluripotency inducing genes Oct4, Nanog and Klf4 argues against a transient pluripotent state during reprogramming. The acquisition of CNS properties is prevented in the presence of BMP4 (BMP NCSCs) as shown by marker gene expression and the potential to produce PNS neurons and glia. In addition, genes characteristic for mesenchymal and perivascular progenitors are expressed, which suggests that BMP NCSCs are directed towards a pericyte progenitor/mesenchymal stem cell (MSC) fate. Adult NCSCs from mouse palate, an easily accessible source of adult NCSCs, display strikingly similar properties. They do not generate cells with CNS characteristics but lose the neural crest markers Sox10 and p75 and produce MSCs. These findings show that embryonic NCSCs acquire a full CNS identity in neurosphere culture. In contrast, MSCs are generated from adult pNCSCs and BMP NCSCs, which reveals that postmigratory NCSCs are a source for MSCs up to the adult stage.
Alternative generation of CNS neural stem cells and PNS derivatives from neural crest-derived peripheral stem cells.
Specimen part
View Samples