Browse
Submit Data
Databases
API
Help

Dataset Information

24 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

GIGANTEA gates gibberellin signaling through stabilization of the DELLA proteins in Arabidopsis.

ABSTRACT: Circadian clock circuitry intersects with a plethora of signaling pathways to adequately time physiological processes to occur at the most appropriate time of the day and year. However, our mechanistic understanding of how the clockwork is wired to its output is limited. Here we uncover mechanistic connections between the core clock component GIGANTEA (GI) and hormone signaling through the modulation of key components of the transduction pathways. Specifically, we show how GI modulates gibberellin (GA) signaling through the stabilization of the DELLA proteins, which act as negative components in the signaling of this hormone. GI function within the GA pathway is required to precisely time the permissive gating of GA sensitivity, thereby determining the phase of GA-regulated physiological outputs.

SUBMITTER: Nohales MA

PROVIDER: S-EPMC6815129 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

GIGANTEA gates gibberellin signaling through stabilization of the DELLA proteins in <i>Arabidopsis</i>.

Nohales Maria A MA Kay Steve A SA

Proceedings of the National Academy of Sciences of the United States of America 20191009 43

Circadian clock circuitry intersects with a plethora of signaling pathways to adequately time physiological processes to occur at the most appropriate time of the day and year. However, our mechanistic understanding of how the clockwork is wired to its output is limited. Here we uncover mechanistic connections between the core clock component GIGANTEA (GI) and hormone signaling through the modulation of key components of the transduction pathways. Specifically, we show how GI modulates gibberell ...[more]

PMID: 31597737

Similar Datasets

Scarecrow-like 3 promotes gibberellin signaling by antagonizing master growth repressor DELLA in Arabidopsis.

Project description:The diterpenoid phytohormone gibberellin (GA) controls diverse developmental processes throughout the plant life cycle. DELLA proteins are master growth repressors that function immediately downstream of the GA receptor to inhibit GA signaling. By doing so, DELLAs also play pivotal roles as integrators of internal developmental signals from multiple hormone pathways and external cues. DELLAs are likely nuclear transcriptional regulators, which interact with other transcription factors to modulate expression of GA-responsive genes. DELLAs are also involved in maintaining GA homeostasis through feedback up-regulating expression of GA biosynthesis and receptor genes. However, the molecular mechanisms by which DELLAs restrict growth and development are largely unknown. This study reveals an important step of the mechanism. Previous microarray studies identified scarecrow-like 3 (SCL3) as a direct target gene of DELLA in Arabidopsis seedlings. SCL3 expression is induced by DELLA and repressed by GA. Unexpectedly, a scl3 null mutant displays reduced GA responses and elevated expression of GA biosynthesis genes during seed germination and seedling growth, indicating that SCL3 functions as a positive regulator of GA signaling. SCL3 seems to act as an attenuator of DELLA proteins. Transient expression, ChIP, and co-IP studies show that SCL3 autoregulates its own transcription by directly interacting with DELLA. Our data further show that SCL3 and DELLA antagonize each other in controlling both downstream GA responses and upstream GA biosynthetic genes. This work is beginning to shed light on how this complex regulatory network achieves GA homeostasis and controls GA-mediated growth and development in the plant.

| S-EPMC3033277 | biostudies-literature

COP1 destabilizes DELLA proteins in Arabidopsis.

Project description:DELLA transcriptional regulators are central components in the control of plant growth responses to the environment. This control is considered to be mediated by changes in the metabolism of the hormones gibberellins (GAs), which promote the degradation of DELLAs. However, here we show that warm temperature or shade reduced the stability of a GA-insensitive DELLA allele in Arabidopsis thaliana Furthermore, the degradation of DELLA induced by the warmth preceded changes in GA levels and depended on the E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). COP1 enhanced the degradation of normal and GA-insensitive DELLA alleles when coexpressed in Nicotiana benthamiana. DELLA proteins physically interacted with COP1 in yeast, mammalian, and plant cells. This interaction was enhanced by the COP1 complex partner SUPRESSOR OF phyA-105 1 (SPA1). The level of ubiquitination of DELLA was enhanced by COP1 and COP1 ubiquitinated DELLA proteins in vitro. We propose that DELLAs are destabilized not only by the canonical GA-dependent pathway but also by COP1 and that this control is relevant for growth responses to shade and warm temperature.

| S-EPMC7306988 | biostudies-literature

The blue light receptor CRY1 interacts with GID1 and DELLA proteins to repress gibberellin signaling and plant growth.

Project description:Improvements in plant architecture, such as reduced plant height under high-density planting, are important for agricultural production. Light and gibberellin (GA) are essential external and internal cues that affect plant architecture. In this study, we characterize the direct interaction of distinct receptors that link light and GA signaling in Arabidopsis (Arabidopsis thaliana) and wheat (Triticum aestivum L.). We show that the light receptor CRY1 represses GA signaling through interaction with all five DELLA proteins and promotion of RGA protein accumulation in Arabidopsis. Genetic analysis shows that CRY1-mediated growth repression is achieved by means of the DELLA proteins. Interestingly, we find that CRY1 also directly interacts with the GA receptor GID1 to competitively inhibit the GID1-GAI interaction. We also show that overexpression of TaCRY1a reduces plant height and coleoptile growth in wheat and that TaCRY1a interacts with both TaGID1 and Rht1 to competitively attenuate the TaGID1-Rht1 interaction. Based on these findings, we propose that the photoreceptor CRY1 competitively inhibits the GID1-DELLA interaction, thereby stabilizing DELLA proteins and enhancing their repression of plant growth.

| S-EPMC8577155 | biostudies-literature

DELLA-mediated PIF degradation contributes to coordination of light and gibberellin signalling in Arabidopsis.

Project description:Light and gibberellins (GAs) antagonistically regulate hypocotyl elongation in plants. It has been demonstrated that DELLAs, which are negative regulators of GA signalling, inhibit phytochrome-interacting factors 3 and 4 (PIF3 and PIF4) by sequestering their DNA-recognition domains. However, it is unclear whether there are other mechanisms of regulatory crosstalk between DELLAs and PIFs. Here, we demonstrate that DELLAs negatively regulate the abundance of four PIF proteins through the ubiquitin-proteasome system. Reduction of PIF3 protein abundance by DELLAs correlates closely with reduced hypocotyl elongation. Both sequestration and degradation of PIF3 by DELLAs contribute to a reduction in PIF3 binding to its target genes. Thus, we show that promotion of PIF degradation by DELLAs is required to coordinate light and GA signals, and the dual regulation of transcription factors by DELLAs by both sequestration and degradation may be a general mechanism.

| S-EPMC4906400 | biostudies-literature

Early gibberellin responses and DELLA protein direct targets in Arabidopsis

Project description:This SuperSeries is composed of the SubSeries listed below.

2007-11-21 | GSE8785 | GEO

Chloroplast Signaling Gates Thermotolerance in Arabidopsis.

Project description:Temperature is a key environmental variable influencing plant growth and survival. Protection against high temperature stress in eukaryotes is coordinated by heat shock factors (HSFs), transcription factors that activate the expression of protective chaperones such as HEAT SHOCK PROTEIN 70 (HSP70); however, the pathway by which temperature is sensed and integrated with other environmental signals into adaptive responses is not well understood. Plants are exposed to considerable diurnal variation in temperature, and we have found that there is diurnal variation in thermotolerance in Arabidopsis thaliana, with maximal thermotolerance coinciding with higher HSP70 expression during the day. In a forward genetic screen, we identified a key role for the chloroplast in controlling this response, suggesting that light-induced chloroplast signaling plays a key role. Consistent with this, we are able to globally activate binding of HSFA1a to its targets by altering redox status in planta independently of a heat shock.

| S-EPMC5847188 | biostudies-literature

Physical and thermodynamic characterization of the rice gibberellin receptor/gibberellin/DELLA protein complex.

Project description:Gibberellins (GAs) are phytohormones that regulate various developmental processes in plants. The initial GA signalling events involve the binding of a GA to the soluble GA receptor protein GID1, followed by the binding of the complex to the negative transcriptional regulator of GA signaling, the DELLA protein. Although X-ray structures for certain Arabidopsis GID1/GA/DELLA protein complexes have previously been determined, examination of these complexes did not fully clarify how a DELLA protein recognizes and binds to a GID1/GA complex. Herein, we present a study aimed at physically defining, via a combination of gel chromatography, isothermal titration calorimetry (ITC), small-angle X-ray scattering experiments (SAXS), NMR spectroscopy and mutagenesis, how the rice DELLA protein (SLR1) binds to the rice GID1/GA complex. We have identified the shortest SLR1 sequence (M28-A112) that binds the rice GID/GA complex tightly. The binding constant for the ternary complex that includes SLR1(M28-A112) is 2.9?×?107?M-1; the binding is enthalpically driven and does not depend on the chemical nature of the bound GA. Furthermore, the results of SAXS, ITC, and gel filtration experiments indicate that when free in solution, SLR1(M28-A112) is a natively unfolded protein. The NMR experiments expand this observation to show that the unfolded mutant also contains a small amount of marginally stable secondary structure. Conversely, the protein has a highly ordered structure when bound one-to-one to GID1/GA.

| S-EPMC6286387 | biostudies-literature

Circadian oscillation of gibberellin signaling in Arabidopsis.

Project description:Circadian clocks are endogenous timekeeping mechanisms that allow organisms to anticipate rhythmic, daily environmental changes. Temporal coordination of transcription results in a set of gene expression patterns with peak levels occurring at precise times of the day. An intriguing question is how a single clock can generate different oscillatory rhythms, and it has been proposed that hormone signaling might act in plants as a relay mechanism to modulate the amplitude and the phase of output rhythms. Here we show that the circadian clock gates gibberellin (GA) signaling through transcriptional regulation of the GA receptors, resulting in higher stability of DELLA proteins during daytime and higher GA sensitivity at night. Oscillation of GA signaling appears to be particularly critical for rhythmic growth, given that constitutive expression of the GA receptor expands the daily growth period in seedlings, and complete loss of DELLA function causes continuous, arrhythmic hypocotyl growth. Moreover, transcriptomic analysis of a pentuple della KO mutant indicates that the GA pathway mediates the rhythmic expression of many clock-regulated genes related to biotic and abiotic stress responses and cell wall modification. Thus, gating of GA sensitivity by the circadian clock represents an additional layer of regulation that might provide extra robustness to the diurnal growth rhythm and constitute a regulatory module that coordinates the circadian clock with additional endogenous and environmental signals.

| S-EPMC3107313 | biostudies-literature

Gibberellin DELLA signaling targets the retromer complex to redirect protein trafficking to the plasma membrane.

Project description:The plant hormone gibberellic acid (GA) is a crucial regulator of growth and development. The main paradigm of GA signaling puts forward transcriptional regulation via the degradation of DELLA transcriptional repressors. GA has also been shown to regulate tropic responses by modulation of the plasma membrane incidence of PIN auxin transporters by an unclear mechanism. Here we uncovered the cellular and molecular mechanisms by which GA redirects protein trafficking and thus regulates cell surface functionality. Photoconvertible reporters revealed that GA balances the protein traffic between the vacuole degradation route and recycling back to the cell surface. Low GA levels promote vacuolar delivery and degradation of multiple cargos, including PIN proteins, whereas high GA levels promote their recycling to the plasma membrane. This GA effect requires components of the retromer complex, such as Sorting Nexin 1 (SNX1) and its interacting, microtubule (MT)-associated protein, the Cytoplasmic Linker-Associated Protein (CLASP1). Accordingly, GA regulates the subcellular distribution of SNX1 and CLASP1, and the intact MT cytoskeleton is essential for the GA effect on trafficking. This GA cellular action occurs through DELLA proteins that regulate the MT and retromer presumably via their interaction partners Prefoldins (PFDs). Our study identified a branching of the GA signaling pathway at the level of DELLA proteins, which, in parallel to regulating transcription, also target by a nontranscriptional mechanism the retromer complex acting at the intersection of the degradation and recycling trafficking routes. By this mechanism, GA can redirect receptors and transporters to the cell surface, thus coregulating multiple processes, including PIN-dependent auxin fluxes during tropic responses.

| S-EPMC5889667 | biostudies-literature

DELLA proteins modulate Arabidopsis defences induced in response to caterpillar herbivory.

Project description:Upon insect herbivory, many plant species change the direction of metabolic flux from growth into defence. Two key pathways modulating these processes are the gibberellin (GA)/DELLA pathway and the jasmonate pathway. In this study, the effect of caterpillar herbivory on plant-induced responses was compared between wild-type Arabidopsis thaliana (L.) Heynh. and quad-della mutants that have constitutively elevated GA responses. The labial saliva (LS) of caterpillars of the beet armyworm, Spodoptera exigua, is known to influence induced plant defence responses. To determine the role of this herbivore cue in determining metabolic shifts, plants were subject to herbivory by caterpillars with intact or impaired LS secretions. In both wild-type and quad-della plants, a jasmonate burst is an early response to caterpillar herbivory. Negative growth regulator DELLA proteins are required for the LS-mediated suppression of hormone levels. Jasmonate-dependent marker genes are induced in response to herbivory independently of LS, with the exception of AtPDF1.2 that showed LS-dependent expression in the quad-della mutant. Early expression of the salicylic acid (SA)-marker gene, AtPR1, was not affected by herbivory which also reflected SA hormone levels; however, this gene showed LS-dependent expression in the quad-della mutant. DELLA proteins may positively regulate glucosinolate levels and suppress laccase-like multicopper oxidase activity in response to herbivory. The present results show a link between DELLA proteins and early, induced plant defences in response to insect herbivory; in particular, these proteins are necessary for caterpillar LS-associated attenuation of defence hormones.

| S-EPMC3904718 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data