Floral development at the Arabidopsis shoot apical meristem occurs in response to environmental cues that are perceived different tissues. Photoperiod is detected vascular tissue of leaf (phloem) and promotes production a systemic signal induces flowering meristem. Vernalization, winter temperatures, overcomes block on photoperiodic floral induction. In , this caused by inhibitors comprise several related MADS-box transcription factors, most prominent which FLC. We show FLC delays repressing...

Abstract In this work, the role of jasmonic acid (JA) in leaf senescence is examined. Exogenous application JA caused premature attached and detached leaves wild-type Arabidopsis but failed to induce precocious JA-insensitive mutantcoi1 plants, suggesting that JA-signaling pathway required for promote senescence. levels senescing are 4-fold higher than non-senescing ones. Concurrent with increase level leaves, genes encoding enzymes catalyze most reactions biosynthetic differentially...

The Arabidopsis autonomous floral-promotion pathway promotes flowering independently of the photoperiod and vernalization pathways by repressing FLOWERING LOCUS C ( FLC ), a MADS-boxtranscription factor that blocks transition from vegetative to reproductive development. Here, we report D FLD one sixgenes in pathway, encodes plant homolog protein found histone deacetylase complexes mammals. Lesions result hyperacetylation histones chromatin, up-regulation expression, extremely delayed...

Polycomb group (PcG) proteins are evolutionarily conserved in animals and plants, play critical roles the regulation of developmental gene expression. Here we show that Arabidopsis repressive complex 2 (PRC2) subunits CURLY LEAF (CLF), EMBRYONIC FLOWER (EMF2) FERTILIZATION INDEPENDENT ENDOSPERM (FIE) repress expression FLOWERING LOCUS C (FLC), a central repressor floral transition FLC relatives. In addition, CLF directly interacts with mediates deposition histone H3 lysine 27 trimethylation...

Plant species have evolved a wide variety of flowering habits, each adapted to maximize reproductive success in their local environment. Even within species, accessions from different environments can exhibit markedly behavior. In Arabidopsis , some are rapid-cycling summer annuals, whereas others late and vernalization responsive thus behave as winter annuals. Two genes, FLOWERING LOCUS C ( FLC ) FRIGIDA FRI ), interact synergistically confer the winter-annual habit. Previous work has shown...

The winter-annual habit (which typically involves a requirement for exposure to the cold of winter flower in spring) Arabidopsis thaliana is mainly due repression flowering by relatively high levels FLC expression. Exposure prolonged attenuates expression through process known as vernalization and thus permits occur spring. Here we show that elevated characteristic nonvernalized annuals requires two genes, EARLY FLOWERING 7 ( ELF7 ) 8 ELF8 ), are homologs components PAF1 complex...

Abstract The last phase of leaf development, generally referred to as senescence, is an integral part plant development that involves massive programmed cell death. Due a sharp decline photosynthetic capacity in leaf, senescence limits crop yield and forest biomass production. However, the biochemical components regulatory mechanisms underlying are poorly characterized. Although several approaches such differential cDNA screening, display, subtraction have been employed isolate...

The timing of the developmental transition to flowering is critical reproductive success in plants. Here, we show that Arabidopsis thaliana homologs human Lysine-Specific Demethylase1 (LSD1; a histone H3-Lys 4 demethylase) reduce levels methylation chromatin floral repressor FLOWERING LOCUS C (FLC) and sporophytically silenced FWA. Two homologs, LSD1-LIKE1 (LDL1) LSD1-LIKE2 (LDL2), act partial redundancy with D (FLD; an additional homolog LSD1) repress FLC expression. However, LDL1 LDL2...

SAG101, a leaf senescence-associated gene, was cloned from an Arabidopsis senescence enhancer trap line and functionally characterized. Reporter gene RNA gel blot analyses revealed that SAG101 not expressed until the onset of in leaves. A recombinant fusion protein overexpressed Escherichia coli displayed acyl hydrolase activity. Antisense interference transgenic plants delayed for ∼4 days. Chemically induced overexpression caused precocious both attached detached leaves plants. These data...

Abstract Winter-annual accessions of Arabidopsis thaliana are often characterized by a requirement for exposure to the cold winter initiate flowering in spring. The block prior is due high levels repressor FLOWERING LOCUS C (FLC). Exposure promotes through process known as vernalization that epigenetically represses FLC expression. Rapid-cycling typically have low expression and therefore do not require vernalization. A screen mutants which winter-annual converted rapid-cycling type has...

Allelic variation in FLOWERING LOCUS C ( FLC ), a central repressor of flowering, contributes to natural differences flowering behavior among Arabidopsis accessions. The weak nature the allele L er accession is due low levels RNA resulting, through an unknown mechanism, from transposable element inserted intron . Here we show that renders -L subject repressive chromatin modifications mediated by short interfering RNAs generated homologous elements genome. Our studies have general...

The developmental transition to flowering is timed by endogenous and environmental signals through multiple genetic pathways. In Arabidopsis, the MADS-domain protein FLOWERING LOCUS C a potent repressor. Here, we report that clade member MADS AFFECTING FLOWERING3 acts redundantly with another directly repress expression of florigen T inhibit flowering. members act in partial redundancy floral repression mediate responses temperature, addition their participation flowering-time regulation...

Histone H3 lysine-4 (H3K4) methylation is associated with transcribed genes in eukaryotes. In Drosophila and mammals, both di- tri-methylation of H3K4 are gene activation. contrast to animals, Arabidopsis trimethylation, but not mono- or di-methylation H3K4, has been implicated transcriptional catalyzed by the methyltransferase complexes known as COMPASS COMPASS-like yeast mammals. Here, we report that homologs complex core components Ash2, RbBP5, WDR5 humans form a nuclear subcomplex during...

In Arabidopsis thaliana, flowering-time variation exists among accessions, and the winter-annual (late-flowering without vernalization) versus rapid-cycling (early flowering) growth habit is typically determined by allelic at FRIGIDA (FRI) FLOWERING LOCUS C (FLC). FRI upregulates expression of FLC, a central floral repressor, to levels that inhibit flowering, resulting in habit. Here, we show promotes histone H3 lysine-4 trimethylation (H3K4me3) FLC upregulate its expression. We identified...

H3K27me3 deposition at FLC requires FCA- COOLAIR binding; SSU72 antagonizes this binding, thus reducing .