Circadian and environmental signal integration in a natural population of .

Plants sense and respond to environmental cues during 24 h fluctuations in their environment. This requires the integration of internal cues such as circadian timing with environmental cues such as light and temperature to elicit cellular responses through signal transduction. However, the integration and transduction of circadian and environmental signals by plants growing in natural environments remains poorly understood.

Seasonal switching of integrated leaf senescence controls in an evergreen perennial Arabidopsis.

Evergreeness is a substantial strategy for temperate and boreal plants and is as common as deciduousness. However, whether evergreen plants switch foliage functions between seasons remains unknown. We conduct an in natura study of leaf senescence control in the evergreen perennial, Arabidopsis halleri.

Levels of photoactivated phototropin modulate signal transmission during the chloroplast accumulation response.

Chloroplasts accumulate in regions of plant cells exposed to irradiation to maximize light reception for efficient photosynthesis. This response is mediated by the blue-light receptor phototropin. Upon the perception of blue light, phototropin is photoactivated, an unknown signal is transmitted from the photoactivated phototropin to distant chloroplasts, and the chloroplasts begin their directional movement.

An improved method for the highly specific detection of transcription start sites.

Precise detection of the transcriptional start site (TSS) is a key for characterizing transcriptional regulation of genes and for annotation of newly sequenced genomes. Here, we describe the development of an improved method, designated 'TSS-seq2.' This method is an iterative improvement of TSS-seq, a previously published enzymatic cap-structure conversion method to detect TSSs in base sequences.

Beyond heat waves: Unlocking epigenetic heat stress memory in Arabidopsis.

Plants remember their exposure to environmental changes and respond more effectively the next time they encounter a similar change by flexibly altering gene expression. Epigenetic mechanisms play a crucial role in establishing such memory of environmental changes and fine-tuning gene expression. With the recent advancements in biochemistry and sequencing technologies, it has become possible to characterize the dynamics of epigenetic changes on scales ranging from short term (minutes) to long term (generations).

Statistical analysis of organelle movement using state-space models.

Background: Organelle motility is essential for the correct cellular function of various eukaryotic cells. In plant cells, chloroplasts move towards the intracellular area irradiated by a weak light to maximise photosynthesis. To initiate this process, an unknown signal is transferred from the irradiated area to distant chloroplasts.

Distinct responses to autumn and spring temperatures by the key flowering-time regulator FLOWERING LOCUS C.

Despite the similarity in temperature regimes between late autumn and early spring, plants exhibit distinct developmental responses that result in distinct morphologies, that is, overwintering and reproductive forms. In Arabidopsis, the control of autumn-spring distinction involves the transcriptional regulation of the floral repressor FLOWERING LOCUS C (FLC). The memory of winter cold is registered as epigenetic silencing of FLC.

The Flowering Season-Meter at FLOWERING LOCUS C Across Life Histories in Crucifers.

Many plant species overwinter before they flower. Transition to flowering is aligned to the seasonal transition as a response to the prolonged cold in winter by a process called vernalization. Multiple well-documented vernalization properties in crucifer species with diverse life histories are derived from environmental regulation of a central inhibitor of the flowering gene, ().

Duration of cold exposure defines the rate of reactivation of a perennial FLC orthologue via H3K27me3 accumulation.

Vernalisation is the process in which long-term cold exposure makes plants competent to flower. In vernalisation of Arabidopsis thaliana, a floral repressor, AtFLC, undergoes epigenetic silencing. Although the silencing of AtFLC is maintained under warm conditions after a sufficient duration of cold, FLC orthologues are reactivated under the same conditions in perennial plants, such as A.

Seasonal plasticity and diel stability of H3K27me3 in natural fluctuating environments.

Diel and seasonal oscillations are two major environmental changes in nature. While organisms cope with the former by the well-characterized mechanism of the circadian clock, there is limited information on the molecular mechanisms underlying long-term responses to the latter. Histone H3 lysine 27 trimethylation (H3K27me3), a repressive histone modification, imparts stability and plasticity to gene regulation during developmental transitions.

Repressive chromatin modification underpins the long-term expression trend of a perennial flowering gene in nature.

Natural environments require organisms to possess robust mechanisms allowing responses to seasonal trends. In Arabidopsis halleri, the flowering regulator AhgFLC shows upregulation and downregulation phases along with long-term past temperature, but the underlying machinery remains elusive. Here, we investigate the seasonal dynamics of histone modifications, H3K27me3 and H3K4me3, at AhgFLC in a natural population.

Seasonal Stability and Dynamics of DNA Methylation in Plants in a Natural Environment.

DNA methylation has been considered a stable epigenetic mark but may respond to fluctuating environments. However, it is unclear how they behave in natural environments. Here, we analyzed seasonal patterns of genome-wide DNA methylation in a single clone from a natural population of the perennial .

The Long-Term "In Natura" Study Sites of Arabidopsis halleri for Plant Transcription and Epigenetic Modification Analyses in Natural Environments.

The majority of organismal phenomena show functional significance in the context of natural environments. However, we know little about how dynamic gene expression is controlled under natural complex conditions. One of the most attractive challenges in current biology is to understand organismal functions in natural environments.

From the laboratory to the field: assaying histone methylation at FLOWERING LOCUS C in naturally growing Arabidopsis halleri.

Gene regulatory mechanisms are often defined in studies performed in the laboratory but are seldom validated for natural habitat conditions, i.e., in natura.