Various genetic interactions of GIGANTEA and EARLY FLOWERING 4 by a functional dominance during a day in Arabidopsis
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE32938 | GEO | 2012/07/01
SECONDARY ACCESSION(S): PRJNA146573
REPOSITORIES: GEO
Similar Datasets
Project description:Plants use their endogenous clock to regulate many physiological processes related to their survival and adaptability. GIGANTEA (GI), one of the clock proteins, contributes to the maintenance of circadian period length and amplitude and also regulates flowering time and hypocotyl growth in response to day length. In addition to GI, EARLY FLOWERING 4 (ELF4), another clock regulator, also contributes to these processes. However, little is known about the overall interactions between GI and ELF4 in Arabidopsis. In this study, we investigated the genetic interactions between GI and ELF4 in circadian output regulation. The results show that GI is dominant to ELF4 in flowering time determination, but ELF4 is dominant to GI in hypocotyl growth regulation. Moreover, GI and ELF4 have a synergistic effect on endogenous clock regulation. Further, gene expression profiling of gi-2, elf4, and gi-2 elf4 mutants confirmed that GI and ELF4 had differential dominant effects on circadian physiological outputs at dawn and dusk, respectively. This differential dominance of GI and ELF4 provides a potential means to achieve the diversity in the regulation of circadian physiological outputs including flowering time and hypocotyl growth. The genetic interactions between GI and ELF4 could be time-dependent functional dominance along a day, called temporal dominance hereafter. To test this hypothesis, we performed gene expression profiling of WT, gi-2, elf4 and gi elf4 plants at dawn (ZT1) and dusk (ZT16).
2012-06-30 | E-GEOD-32938 | biostudies-arrayexpress
Project description:The circadian clock represents a critical regulatory network, which allows plants to anticipate environmental changes as inputs and promote plant survival by regulating various physiological outputs. Here, we examine the function of the clock-regulated transcription factor, CYCLING DOF FACTOR 6 (CDF6), during cold stress in Arabidopsis thaliana. We found that the clock gates CDF6 transcript accumulation in the vasculature during cold stress. CDF6 mis-expression results in an altered flowering phenotype during both ambient and cold stress. A genome-wide transcriptome analysis links CDF6 to genes associated with flowering and seed germination during cold and ambient temperatures, respectively. Analysis of key floral regulators indicates that CDF6 alters flowering during cold stress by repressing photoperiodic flowering components, FLOWERING LOCUS T (FT), CONSTANS (CO), and BROTHER OF FT (BFT). Gene ontology enrichment further suggests that CDF6 regulates circadian and developmental associated genes. These results provide insight into how the clock-controlled CDF6 modulates plant development during moderate cold stress.
2022-07-01 | GSE197581 | GEO
Project description:GIGANTEA (GI) is a plant-specific, circadian clock-regulated, nuclear protein with pleiotropic functions studied in many plant species. It is involved in flowering, circadian clock control, chloroplast biogenesis, carbohydrate metabolism, stress responses and synthesis of volatiles. In potato (Solanum tuberosum L.), however, only its role in tuber initiation is reported. Based on the findings in other plant species we hypothesized that the function of GI is not restricted to tuberization in potato. To test this hypothesis we repressed the expression of a GI gene, StGI.04 in the commercial potato cultivar ‘Désirée’ and investigated the effect of repression at morphological and transcriptome level. We found that, like GI in other plant species, StGI.04 influences the expression of the key genes of circadian clock, flowering, starch synthesis and stress responses. Furthermore, we detected a novel function of a GI gene in influencing the anthocyanin synthesis and skin colour of potato tubers.
2022-03-30 | GSE189956 | GEO
Project description:Plant responses to the environment are shaped by the external stimuli and internal signaling pathways. In both the model plant Arabidopsis thaliana and crop species, circadian clock factors have been identified as critical for growth, flowering and circadian rhythms. Outside of A. thaliana, however, little is known about the molecular function of clock genes. Therefore, we sought to compare the function of Brachypodium distachyon and Seteria viridis orthologs of EARLY FLOWERING3, a key clock gene in A. thaliana. To identify both cycling genes and putative ELF3 functional orthologs in S. viridis, a circadian RNA-seq dataset and online query tool (Diel Explorer) was generated as community resource to explore expression profiles of Setaria genes under constant conditions after photo- or thermo-entrainment. The function of ELF3 orthologs from A. thaliana, B. distachyon, and S. viridis were tested for complementation of an elf3 mutation in A. thaliana. Despite comparably low sequence identity versus AtELF3 (< 37%), both monocot orthologs were capable of rescuing hypocotyl elongation, flowering time and arrhythmic clock phenotypes. Molecular analysis using affinity purification and mass spectrometry to compare physical interactions also found that BdELF3 and SvELF3 could be integrated into similar complexes and networks as AtELF3, including forming a composite evening complex. Thus, we find that, despite 180 million years of separation, BdELF3 and SvELF3 can functionally complement loss of ELF3 at the molecular and physiological level.
2018-01-08 | PXD006352 | Pride
Project description:The circadian clock is comprised of proteins that form negative feedback loops, which regulate the timing of global gene expression in a coordinated 24 hour cycle. As a result, the plant circadian clock is responsible for regulating numerous physiological processes central to growth and survival. To date, most plant circadian clock studies have relied on diurnal transcriptome changes to elucidate molecular connections between the circadian clock and observable phenotypes in wild-type plants. Here, we have combined high-throughput RNA-sequencing and mass spectrometry to comparatively characterize the lhycca1, prr7prr9, gi and toc1 circadian clock mutant rosette transcriptome and proteome at the end-of-day and end-of-night.
2018-01-02 | PXD004763 | Pride
Project description:Plants monitor and integrate temperature, photoperiod and light quality signals to respond to continuous changes in their environment. The GIGANTEA (GI) protein is central in diverse signaling pathways, including photoperiodic, sugar and light signaling pathways, stress responses and circadian clock regulation. Previously, GI was shown to activate expression of the key floral regulators CONSTANS (CO) and FLOWERING LOCUS T (FT) by facilitating degradation of a family of CYCLING DOF FACTOR (CDF) transcriptional repressors. However, whether CDFs are implicated in other processes regulated by GI remains unclear. We investigated the contribution of the GI-CDF module to traits that depend on GI. Transcriptome profiling indicated that mutations in GI and the CDFs have antagonistic effects on expression of a wider set of genes than CO and FT, whilst other genes are regulated by GI independently of the CDFs. Detailed expression studies followed by phenotypic assays showed that the CDFs function downstream of GI to control responses to freezing temperatures and growth, but are not necessary for proper clock function. Thus GI-mediated regulation of CDFs contributes to several processes in addition to flowering, but is not implicated in all of the phenotypes influenced by GI.
2015-07-31 | GSE59996 | GEO
Project description:Plants monitor and integrate temperature, photoperiod and light quality signals to respond to continuous changes in their environment. The GIGANTEA (GI) protein is central in diverse signaling pathways, including photoperiodic, sugar and light signaling pathways, stress responses and circadian clock regulation. Previously, GI was shown to activate expression of the key floral regulators CONSTANS (CO) and FLOWERING LOCUS T (FT) by facilitating degradation of a family of CYCLING DOF FACTOR (CDF) transcriptional repressors. However, whether CDFs are implicated in other processes regulated by GI remains unclear. We investigated the contribution of the GI-CDF module to traits that depend on GI. Transcriptome profiling indicated that mutations in GI and the CDFs have antagonistic effects on expression of a wider set of genes than CO and FT, whilst other genes are regulated by GI independently of the CDFs. Detailed expression studies followed by phenotypic assays showed that the CDFs function downstream of GI to control responses to freezing temperatures and growth, but are not necessary for proper clock function. Thus GI-mediated regulation of CDFs contributes to several processes in addition to flowering, but is not implicated in all of the phenotypes influenced by GI. Seedlings of Col-0, the cdf1-R cdf2-1 cdf3-1 cdf5-1 quadruple mutant, gi-100 and gi-100 cdf1-R cdf2-1 cdf3-1 cdf5-1 quintuple mutant were grown for 10 days under LD conditions (16h light/8h dark). The aerial part of the seedlings was collected at ZT12 and RNA was prepared from three biological replicas
2015-07-31 | E-GEOD-59996 | biostudies-arrayexpress
Project description:Pokhilko2013 - TOC1 signalling in Arabidopsis
circadian clock
In this model, Pokhilko
et al. has incorporated the negative transcriptional
regulations of the core clock genes by TOC1 and the up-regulation
of TOC1 expression by ABA signalling, to their previous model
BIOMD0000000412
This model is described in the article:
Modelling the widespread
effects of TOC1 signalling on the plant circadian clock and its
outputs.
Pokhilko A, Mas P, Millar AJ.
BMC Syst Biol 2013; 7: 23
Abstract:
BACKGROUND: 24-hour biological clocks are intimately
connected to the cellular signalling network, which complicates
the analysis of clock mechanisms. The transcriptional regulator
TOC1 (TIMING OF CAB EXPRESSION 1) is a founding component of
the gene circuit in the plant circadian clock. Recent results
show that TOC1 suppresses transcription of multiple target
genes within the clock circuit, far beyond its
previously-described regulation of the morning transcription
factors LHY (LATE ELONGATED HYPOCOTYL) and CCA1 (CIRCADIAN
CLOCK ASSOCIATED 1). It is unclear how this pervasive effect of
TOC1 affects the dynamics of the clock and its outputs. TOC1
also appears to function in a nested feedback loop that
includes signalling by the plant hormone Abscisic Acid (ABA),
which is upregulated by abiotic stresses, such as drought. ABA
treatments both alter TOC1 levels and affect the clock's timing
behaviour. Conversely, the clock rhythmically modulates
physiological processes induced by ABA, such as the closing of
stomata in the leaf epidermis. In order to understand the
dynamics of the clock and its outputs under changing
environmental conditions, the reciprocal interactions between
the clock and other signalling pathways must be integrated.
RESULTS: We extended the mathematical model of the plant clock
gene circuit by incorporating the repression of multiple clock
genes by TOC1, observed experimentally. The revised model more
accurately matches the data on the clock's molecular profiles
and timing behaviour, explaining the clock's responses in TOC1
over-expression and toc1 mutant plants. A simplified
representation of ABA signalling allowed us to investigate the
interactions of ABA and circadian pathways. Increased ABA
levels lengthen the free-running period of the clock,
consistent with the experimental data. Adding stomatal closure
to the model, as a key ABA- and clock-regulated downstream
process allowed to describe TOC1 effects on the rhythmic gating
of stomatal closure. CONCLUSIONS: The integrated model of the
circadian clock circuit and ABA-regulated environmental sensing
allowed us to explain multiple experimental observations on the
timing and stomatal responses to genetic and environmental
perturbations. These results crystallise a new role of TOC1 as
an environmental sensor, which both affects the pace of the
central oscillator and modulates the kinetics of downstream
processes.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000445.
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To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
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2013-03-22 | BIOMD0000000445 | BioModels
Project description:Plants are sessile organisms that have acquired highly plastic developmental strategies to adapt to the environment. Among these processes, the floral transition is essential to ensure reproductive success and is finely regulated by several internal and external genetic networks. The photoperiodic pathway, which controls the plant response to day length, is one of the most important pathways controlling flowering. In Arabidopsis photoperiodic flowering, CONSTANS (CO) is the central gene activating the expression of the florigen FLOWERING LOCUS T (FT) in the leaves at the end of a long day. CO expression is strongly regulated by the circadian clock. However, to date, no evidence has been reported regarding a feedback loop from the photoperiod pathway back to the circadian clock. Using transcriptional networks, we have identified relevant network motifs regulating the interplay between the circadian clock and the photoperiod pathway. Gene expression, chromatin immunoprecipitation experiments and phenotypic analysis allowed us to elucidate the role of CO over the circadian clock. Plants with altered CO expression showed a different internal clock period, measured by daily rhythmic movements in the leaves. We show that CO is able to activate key genes related to the circadian clock, such as CCA1, LHY, PRR5 and GI, at the end of a long day by binding to specific sites on their promoters. Moreover, a significant number of PRR5 repressed target genes are upregulated by CO, and this could explain the phase transition promoted by CO. The CO-PRR5 complex interacts with the bZIP transcription factor HY5 and helps to localize the complex in the promoters of clock genes. Our results indicate that there may be a feedback loop in which CO communicates back to the circadian clock, feeding seasonal information to the circadian system.
2023-08-01 | GSE236178 | GEO
Project description:Plants are sessile organisms that have acquired highly plastic developmental strategies to adapt to the environment. Among these processes, the floral transition is essential to ensure reproductive success and is finely regulated by several internal and external genetic networks. The photoperiodic pathway, which controls the plant response to day length, is one of the most important pathways controlling flowering. In Arabidopsis photoperiodic flowering, CONSTANS (CO) is the central gene activating the expression of the florigen FLOWERING LOCUS T (FT) in the leaves at the end of a long day. CO expression is strongly regulated by the circadian clock. However, to date, no evidence has been reported regarding a feedback loop from the photoperiod pathway back to the circadian clock. Using transcriptional networks, we have identified relevant network motifs regulating the interplay between the circadian clock and the photoperiod pathway. Gene expression, chromatin immunoprecipitation experiments and phenotypic analysis allowed us to elucidate the role of CO over the circadian clock. Plants with altered CO expression showed a different internal clock period, measured by daily rhythmic movements in the leaves. We show that CO is able to activate key genes related to the circadian clock, such as CCA1, LHY, PRR5 and GI, at the end of a long day by binding to specific sites on their promoters. Moreover, a significant number of PRR5 repressed target genes are upregulated by CO, and this could explain the phase transition promoted by CO. The CO-PRR5 complex interacts with the bZIP transcription factor HY5 and helps to localize the complex in the promoters of clock genes. Our results indicate that there may be a feedback loop in which CO communicates back to the circadian clock, feeding seasonal information to the circadian system.
2024-01-01 | GSE222657 | GEO