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ChIP analysis of levels of acetylated histone H3 in Col and afr1 afr2 rosette leaves. Amounts of the immunoprecipitated genomic fragments were quantified by qPCR. The fold enrichments were calculated as follows: for each examined FT region, the amount of DNA fragments from WT or afr1 afr2 at each time point (ZT8 or ZT16) was first normalized to the constitutively expressed TUBULIN2 (TUB2) in each sample, and subsequently, the TUB2-normalized values for the afr1 afr2 at ZT8, the afr1 afr2 at ZT16, or the WT at ZT16 were divided by the value for the WT at ZT8 to obtain fold enrichments. Shown are the means and SD of two ChIP experiments. An analysis of H3 acetylation on FT chromatin in Col and afr1 afr2 seedlings is presented in Figure S11.
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The developmental transition from a vegetative to a reproductive phase (i.e., flowering) is timed by the seasonal cue day length or photoperiod in many plant species. Through the photoperiod pathway, inductive day lengths trigger the production of a systemic flowering signal, florigen, to provoke the floral transition. FLOWERING LOCUS T (FT), widel...
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Floral transition from the vegetative to the reproductive stages is precisely regulated by both environmental and endogenous signals. Among these signals, photoperiod is one of the most important environmental factors for onset of flowering. A florigen, FLOWERING LOCUS T (FT) in Arabidopsis, has thought to be a major hub in the photoperiod-dependen...
Plants possess an extraordinarily well adapted system to respond to external cues mainly to temperature and light. Light is the most important parameter that shapes the development of a plant. Plants respond to quality, intensity, direction and duration of the light signal to bring in a developmental transition. The photoperiod pathway is initiated...
Change in phenology has been an important component in crop evolution, and selection for earlier flowering through a reduction in environmental sensitivity has helped broaden adaptation in many species. Natural variation for flowering in domesticated pea (Pisum sativum L.) has been noted and studied for decades, but there has been no clear account...
Three aspects of the physiology of flowering in photoperiodic sensitive plants are discussed. These are the florigen hypothesis, phytochrome and the time measurement mechanism of flowering and genetic-molecular studies involved in flowering. There is evidence that the hypothetical compound, florigen, occurs in plants, but it has never been characte...
Key message
A novel Hd3a allele strongly promoting rice heading date was identified, and it functions through florigen activation complex (FAC) and was selected during the spread of rice cultivation to high-latitude areas.
Abstract
Heading date is a critical agronomic trait for rice that determines the utilization of light and temperature conditio...
Citations
... FT is an important component of the photoperiodic regulation of flowering. 19 In tomato, three MADS-domain proteins expressed during flowering and fruit formation Lycopersicon esculentum MADS1, 5, and 6 (LeMADS1, LeMADS5, and LeMADS6) possess a histone deacetylase binding domain which is needed to interact with mammalian HDA5. 8 In addition, Solanum lycopersicum HDA1, 3, and 4 (SlHDA1, SlHDA3 and SlHDA4; members of the RPD3/HDA1 family) interacted with TOMATO AGAMOUS1 (TAG1), and TOMATO MADS BOX29 (TM29). ...
Cellular behavior, cell differentiation and ontogenetic development in eukaryotes result from complex interactions between epigenetic and classic molecular genetic mechanisms, with many of these interactions still to be elucidated. Histone deacetylase enzymes (HDACs) promote the interaction of histones with DNA by compacting the nucleosome, thus causing transcriptional repression. MADS-domain transcription factors are highly conserved in eukaryotes and participate in controlling diverse developmental processes in animals and plants, as well as regulating stress responses in plants. In this work, we focused on finding out putative interactions of Arabidopsis thaliana HDACs and MADS-domain proteins using an evolutionary perspective combined with bioinformatics analyses and testing the more promising predicted interactions through classic molecular biology tools. Through bioinformatic analyses, we found similarities between HDACs proteins from different organisms, which allowed us to predict a putative protein-protein interaction between the Arabidopsis thaliana deacetylase HDA15 and the MADS-domain protein XAANTAL1 (XAL1). The results of two-hybrid and Bimolecular Fluorescence Complementation analysis demonstrated in vitro and in vivo HDA15-XAL1 interaction in the nucleus. Likely, this interaction might regulate developmental processes in plants as is the case for this type of interaction in animals.
... In these pathways, the expression levels of FLOWERING LOCUS T (FT), CONSTANS (CO), SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), and FLOWERING LOCUS C (FLC) are precisely regulated as core elements [20,21]. FT is the major component of the mobile florigen, which is transported through the phloem from the leaf to the shoot apical meristem (SAM) to promote flowering via the photoperiod pathway [22]. The photoperiod pathway outputs CO, whose expression is controlled via the circadian clock, to promote FT expression in leaf veins [23]. ...
SECRETORY13 (SEC13) is an essential member of the coat protein complex II (COPII), which was reported to mediate vesicular-specific transport from the endoplasmic reticulum (ER) to the Golgi apparatus and plays a crucial role in early secretory pathways. In Arabidopsis, there are two homologous proteins of SEC13: SEC13A and SEC13B. SUPPRESSOR OF FRIGIDA 4 (SUF4) encodes a C2H2-type zinc finger protein that inhibits flowering by transcriptionally activating the FLOWERING LOCUS C (FLC) through the FRIGIDA (FRI) pathway in Arabidopsis. However, it remains unclear whether SEC13 proteins are involved in Arabidopsis flowering. In this study, we first identified that the sec13b mutant exhibited early flowering under both long-day and short-day conditions. Quantitative real-time PCR (qRT–PCR) analysis showed that both SEC13A and SEC13B were expressed in all the checked tissues, and transient expression assays indicated that SEC13A and SEC13B were localized not only in the ER but also in the nucleus. Then, we identified that SEC13A and SEC13B could interact with SUF4 in vitro and in vivo. Interestingly, both sec13b and suf4 single mutants flowered earlier than the wild type (Col-0), whereas the sec13b suf4 double mutant flowered even earlier than all the others. In addition, the expression of flowering inhibitor FLC was down-regulated, and the expressions of flowering activator FLOWERING LOCUS T (FT), CONSTANS (CO), and SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1) were up-regulated in sec13b, suf4, and sec13b suf4 mutants, compared with Col-0. Taken together, our results indicated that SEC13B interacted with SUF4, and they may co-regulate the same genes in flowering-regulation pathways. These results also suggested that the COPII component could function in flowering in Arabidopsis.
... FT expression is inhibited by the Polycomb silencing complex in the afternoon because it is more abundant than SOC1 in leaf veins . FT expression is regulated through SOC1 by binding to its promoter region and affecting histone modifiers, thus controlling the expression of the FT gene (Takeno, 2013;Gu et al., 2013;. SOC1 comes in contact with MRG1 and MRG2 (MORF RELATED GENE 1 and 2), which bind to H3K36me3 and H3K4me3 at the FT locus, thus activating its expression more rapidly Bu et al., 2014). ...
Seasonal changes are crucial in shifting the developmental stages from the vegetative phase to the reproductive
phase in plants, enabling them to flower under optimal conditions. Plants grown at different latitudes sense and
interpret these seasonal variations, such as changes in day length (photoperiod) and exposure to cold winter
temperatures (vernalization). These environmental factors influence the expression of various genes related to
flowering. Plants have evolved to stimulate a rapid response to environmental conditions through genetic and
epigenetic mechanisms. Multiple epigenetic regulation systems have emerged in plants to interpret environmental
signals. During the transition to the flowering phase, changes in gene expression are facilitated by
chromatin remodeling and small RNAs interference, particularly in annual and perennial plants. Key flowering
regulators, such as FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT), interact with various factors
and undergo chromatin remodeling in response to seasonal cues. The Polycomb silencing complex (PRC) controls
the expression of flowering-related genes in photoperiodic flowering regulation. Under vernalization-dependent
flowering, FLC acts as a potent flowering suppressor by downregulating the gene expression of various flower-
promoting genes. Eventually, PRCs are critically involved in the regulation of FLC and FT locus interacting
with several key genes in photoperiod and vernalization. Subsequently, PRCs also regulate Epigenetical events
during gametogenesis and seed development as a driving force. Furthermore, DNA methylation in the context of
CHG, CG, and CHH methylation plays a critical role in embryogenesis. DNA glycosylase DME (DEMETER) is
responsible for demethylation during seed development. Thus, the review briefly discusses flowering regulation
through light signaling, day length variation, temperature variation and seed development in plants.
... PWR is required for deacetylation of H3K9 at the +1 nucleosome of PIF4 and its target YUCCA8 (YUC8). Furthermore, increased deacetylation of FT chromatin is observed under inductive long-day conditions [89]. A deeper exploration of how temperature influences FT chromatin status would provide more comprehensive insights into the molecular regulatory mechanisms of these phenomena. ...
The timing of floral transition is determined by both endogenous molecular pathways and external environmental conditions. Among these environmental conditions, photoperiod acts as a cue to regulate the timing of flowering in response to seasonal changes. Additionally, it has become clear that various environmental factors also control the timing of floral transition. Environmental factor acts as either a positive or negative signal to modulate the timing of flowering, thereby establishing the optimal flowering time to maximize the reproductive success of plants. This review aims to summarize the effects of environmental factors such as photoperiod, light intensity, temperature changes, vernalization, drought, and salinity on the regulation of flowering time in plants, as well as to further explain the molecular mechanisms that link environmental factors to the internal flowering time regulation pathway.
... FT expression is inhibited by the Polycomb silencing complex in the afternoon because it is more abundant than SOC1 in leaf veins (Luo et al., 2018;Wang et al., 2014). FT expression is regulated through SOC1 by binding to its promoter region and affecting histone modifiers, thus controlling the expression of the FT gene (Gu et al., 2013;Wang et al., 2014). ...
Plants grown at different latitudes perceive and interpret seasonal variations in day length (photoperiod) and exposure to cold winter temperatures (vernalization). These factors control the expression of various genes involved in flowering, depending on the variations in photoperiod and vernalization. Epigenetic regulatory systems have evolved in plants to process environmental signals. Gene expression is modified through chromatin remodelling and small RNAs in response to seasonal changes in both annual and perennial plants. Key regulators of flowering, such as FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT), interact with other floral regulatory factors and undergo chromatin remodelling in response to seasonal cues. The Poly-comb repressive complex (PRC) controls the expression of flowering-related genes in photoperiodic flowering regulation. FLC acts as a potent suppressor by down-regulating the expression of genes that promote flowering. Methylation, particularly in the context of CHG, CG and CHH, plays a critical role in embryogenesis. This review briefly explores and describes the regulation of flowering mechanisms in response to day-length variations, cold exposure (vernalization) and seed development in plants. K E Y W O R D S chromatin remodelling, epigenetics, flowering regulation, photoperiod, plant aging, seed development, vernalization
... Walnut trees have a relatively long juvenile stage (defined as the time from the vegetative to the reproductive phase), usually taking 8-10 years to undergo floral transition. In plants, the floral transition is regulated by several exogenous and endogenous stimuli to ensure the correct timing [7,8]. In the model plant Arabidopsis thaliana, flowering is controlled by various pathways including the photoperiod, vernalization, autonomous, and gibberellin pathways. ...
Walnut (Juglans regia L.) plants typically flower after eight to ten years of juvenile growth. Precocious germplasm, also known as early-flowering or early-mature genotypes, have shortened juvenile phases of one to two years and are therefore crucial for enhancing breeding efficiency. However, such precocious germplasms are very limited. Here, we isolated and characterized the key flowering-time gene FLOWERING LOCUS C (FLC) in the precocious walnuts of the Xinjiang Uygur Autonomous Region. Sequence alignment showed that Juglans regia FLC (JrFLC)contained a conserved MINICHROMOSOME MAINTENANCE 1 (MCM1), AGAMOUS (AG), DEFICIENS (DEF), and SERUM RESPONSE FACTOR (SRF) (MADS)-box domain. Analysis of an FLC–green fluorescent protein (GFP) fusion protein revealed that JrFLC was localized to the nucleus. Gene expression analysis showed that JrFLC was specifically expressed during the bud dormancy stage of precocious walnut, and that expression levels gradually decreased as the ambient temperature warmed. Exogenous JrFLC overexpression in Arabidopsis thaliana delayed flowering and increased the total leaf number, suggesting a similar function of JrFLC as a floral repressor in walnut and in other plants. Together, these results showed that JrFLC played an important role in regulating the floral transition of Xinjiang precocious walnut. Further studies, including a detailed characterization of JrFLC, are expected to validate JrFLC as a strong target for genetic improvement in flowering time in walnut.
... Under LD conditions, HD2C is recruited by MRG1/2 to the promoter of FT to deacetylate histone and repress the transcription of FT at the end of day . Besides, SAP30 function related 1 (AFR1) and AFR2 protein, a part of HDAC complexes (AFR1-HDAC or AFR2-HDAC), accumulate and deacetylate the FT chromatin to decrease the expression of FT at the end of day (Gu et al., 2013). Although HDA5 and HDA6 are also involved in flowering, their regulation is independent of photoperiodic pathway (Ning et al., 2019). ...
In response to changeable season, plants precisely control the initiation of flowering in appropriate time of the year to ensure reproductive success. Day length (photoperiod) acts as the most important external cue to determine flowering time. Epigenetics regulates many major developmental stages in plant life, and emerging molecular genetics and genomics researches reveal their essential roles in floral transition. Here, we summarize the recent advances in epigenetic regulation of photoperiod‐mediated flowering in Arabidopsis and rice, and discuss the potential of epigenetic regulation in crops improvement, and give the brief prospect for future study trends.
... AtING2 also interacts with other proteins, including SIN3A ASSOCIATED PROTEIN 18 (SAP18) and SHORT LIFE 1 (SHL1), indicating that it may be part of a repressive chromatin complex (Lopez-Gonzalez et al., 2014;Perrella et al., 2016). Here, we carried out yeast two-hybrid assays ( Figure S2) to test whether MtING1 and MtING2 interact with putative Medicago members of an HDAC complex regulating flowering time in Arabidopsis (Gu et al., 2013) including SAP18 (Perrella et al., 2016). However, no interactions were observed. ...
Flowering of the reference legume Medicago truncatula is promoted by winter cold (vernalization) followed by long day photoperiods (VLD) similar to winter annual Arabidopsis. However, Medicago lacks FLC and CO, key regulators of Arabidopsis VLD flowering. Most plants have two INHIBITOR OF GROWTH (ING) genes (ING1 and ING2), encoding proteins with an ING domain with two anti‐parallel alpha helices and a plant homeodomain (PHD) finger, but their genetic role has not been previously described. In Medicago, Mting1 gene‐edited mutants developed and flowered normally, but a Mting2‐1 Tnt1 insertion mutant and gene‐edited Mting2 mutants had developmental abnormalities including delayed flowering particularly in VLD, compact architecture, abnormal leaves with extra leaflets but no trichomes and smaller seeds and barrels. Mting2 mutants had reduced expression of activators of flowering including the FT‐like gene MtFTa1, and increased expression of the candidate repressor MtTFL1c, consistent with the delayed flowering of the mutant. MtING2 overexpression complemented Mting2‐1, but did not accelerate flowering in wild type. The MtING2 PHD finger bound H3K4me2/3 peptides weakly in vitro, but analysis of gene‐edited mutants indicated that it was dispensable to MtING2 function in wild type plants. RNA‐seq experiments indicated that >7,000 genes are mis‐expressed in the Mting2‐1 mutant consistent with its strong mutant phenotypes. Interestingly, ChIP‐seq analysis identified >5,000 novel H3K4me3 locations in the genome of Mting2‐1 mutants compared to wild type R108. Overall, our mutant study has uncovered an important physiological role of a plant ING2 gene in development, flowering, and gene expression, which likely involves an epigenetic mechanism.
... Since timing of fowering is crucial to the life cycle of plants, it is not surprising that plants constantly monitor environmental signals to adjust the timing of the foral transition (Capovilla et al., 2015), but it is amazing that this is exquisitely sensitive to the GMF. Plant fowering time is controlled by several genes, including circadian clock-associated genes (Hara et al., 2014), genes involved both in the transition from the vegetative to the reproductive phase (Gu et al., 2013) and in the precise control of fowering (Song et al., 2014), and microRNA regulation (Spanudakis and Jackson, 2014;Hong and Jackson, 2015). Current models provide us with a basis on which to address a number of fundamental issues for a better understanding of the molecular mechanisms by which plants respond to environmental stimuli to control fowering time (Fornara et al., 2010). ...
As sessile organisms, plants have evolved both constitutive and inducible responses to the changing environment. Several environmental factors affect plant growth and development. Among them, the Earth magnetic field or geomagnetic field (GMF) is an environmental component of our planet. This chapter highlights some of the basic mechanisms proposed to be involved in plant magnetoreception and summarizes the plant responses to varying MF intensities both dependent and independent from the presence of light. The different mechanisms of magnetoreception include: a mechanism involving radical pairs, which has been demonstrated both in animals and in plants; the presence of MF sensory receptors present in cells containing ferromagnetic particles, as has been shown in magnetotactic bacteria; and the detection of minute electric fields by electroreceptors in the ampullae of Lorenzini in elasmobranch animals.
... The reduction in miR156 accumulation in agl15 agl18 double mutants demonstrates that AGL15 and AGL18 function as co-regulators with miR156 in the determination of flowering time in Arabidopsis. AGL15 and AGL18 interact with putative CArG motifs in the MIR156 promoter both in vitro and in vivo [96][97][98]. ...
Rice (Oryza sativa L.) and Arabidopsis thaliana (L.) life cycles involve several major phase changes, throughout which MADS-box genes have a variety of functions. MADS-box genes are well recognized for their functions in floral induction and development, and some have multiple functions in apparently unrelated developmental stages. For example, in Arabidopsis, AGL15 and AGL6 play roles in both vegetative development and floral transition. Similarly, in rice, OsMADS1 is involved in flowering time and seed development, and OsMADS26 is expressed not only in the roots, but also in the leaves, shoots, panicles, and seeds. The roles of other MADS-box genes responsible for the regulation of specific traits in both rice and Arabidopsis are also discussed. Several are key components of gene regulatory networks involved in root development under diverse environmental factors such as drought, heat, and salt stress, and are also involved in the shift from vegetative to flowering growth in response to seasonal changes in environmental conditions. Thus, we argue that MADS-box genes are critical elements of gene regulation that underpin diverse gene expression profiles, each of which is linked to a unique developmental stage that occurs during root development and the shift from vegetative to reproductive growth.
