Let it bloom: crosstalk between light and flowering signalling in Arabidopsis

The terrestrial environment is complex, with many parameters fluctuating on daily and seasonal basis. Plants in particular, have developed complex sensory and signalling networks to extract and integrate information about their surroundings, in order to maximise their fitness and mitigate some of the detrimental effects of their sessile lifestyles. Light and temperature each provide crucial insight on the surrounding environment and in combination allow plants to appropriately develop, grow and adapt. Crosstalk between light and temperature signalling cascades allow plants to time key developmental decisions accordingly to ensure they are “in sync” with their environment. In this review, we discuss the major players that regulate light and temperature signalling, and the cross‐talk between them, in reference to a crucial developmental decision faced by plants: to bloom or not to bloom

HISTONE DEACETYLASE 9 stimulates auxin-dependent thermomorphogenesis in Arabidopsis thaliana by mediating H2A.Z depletion

Many plant species respond to unfavorable high ambient temperatures by adjusting their vegetative body plan to facilitate cooling. This process is known as thermomorphogenesis and is induced by the phytohormone auxin. Here, we demonstrate that the chromatin-modifying enzyme HISTONE DEACETYLASE 9 (HDA9) mediates thermomorphogenesis but does not interfere with hypocotyl elongation during shade avoidance. HDA9 is stabilized in response to high temperature and mediates histone deacetylation at the YUCCA8 locus, a rate-limiting enzyme in auxin biosynthesis, at warm temperatures. We show that HDA9 permits net eviction of the H2A.Z histone variant from nucleosomes associated with YUCCA8, allowing binding and transcriptional activation by PHYTOCHROME INTERACTING FACTOR 4, followed by auxin accumulation and thermomorphogenesis

Investigating the role of chromatin modification and hormone signalling components in regulating light and temperature responses in Arabidopsis thaliana

Abstract not currently available

Low fluence ultraviolet-B promotes ultraviolet resistance 8-modulated flowering in Arabidopsis

Ultraviolet-B (UV-B) irradiation (280–320 nm) is an integral part of sunlight and a pivotal environmental cue that triggers various plant responses, from photoprotection to photomorphogenesis and metabolic processes. UV-B is perceived by ULTRAVIOLET RESISTANCE 8 (UVR8), which orchestrates UV-B signal transduction and transcriptional control of UV-B-responsive genes. However, there is limited information on the molecular mechanism underlying the UV-B- and UVR8-dependent regulation of flowering time in plants. Here, we investigate the role of UV-B and UVR8 in photoperiodic flowering in Arabidopsis thaliana. Our findings suggest that UV-B controls photoperiodic flowering in an ecotype-specific manner and that UVR8 acts as a negative regulator of UV-B-induced flowering. Overall, our research shows that UV-B modulates flowering initiation through the action of UVR8 at the transcriptional level

The epigenetic mechanisms underlying thermomorphogenesis and heat stress responses in Arabidopsis

Integration of temperature cues is crucial for plant survival and adaptation. Global warming is a prevalent issue, especially in modern agriculture, since the global rise in average temperature is expected to impact crop productivity worldwide. Hence, better understanding of the mechanisms by which plants respond to warmer temperatures is very important. This review focuses on the epigenetic mechanisms implicated in plant responses to high temperature and distinguishes the different epigenetic events that occur at warmer average temperatures, leading to thermomorphogenic responses, or subjected to extreme warm temperatures, leading to heat stress

Let it bloom: cross‐talk between light and flowering signaling in Arabidopsis

The terrestrial environment is complex, with many parameters fluctuating on daily and seasonal basis. Plants in particular, have developed complex sensory and signalling networks to extract and integrate information about their surroundings, in order to maximise their fitness and mitigate some of the detrimental effects of their sessile lifestyles. Light and temperature each provide crucial insight on the surrounding environment and in combination allow plants to appropriately develop, grow and adapt. Crosstalk between light and temperature signalling cascades allow plants to time key developmental decisions accordingly to ensure they are “in sync” with their environment. In this review, we discuss the major players that regulate light and temperature signalling, and the cross‐talk between them, in reference to a crucial developmental decision faced by plants: to bloom or not to bloom

Light, chromatin, action: nuclear events regulating light signaling in Arabidopsis

The plant nucleus provides a major hub for environmental signal integration at the chromatin level. Multiple light signaling pathways operate and exchange information by regulating a large repertoire of gene targets that shape plant responses to a changing environment. In addition to the established role of transcription factors in triggering photo-regulated changes in gene expression, there are eminent reports on the significance of chromatin regulators and nuclear scaffold dynamics in promoting light-induced plant responses. Here, we report and discuss recent advances in chromatin-regulatory mechanisms modulating plant architecture and development in response to light, including the molecular and physiological roles of key modifications such as DNA, RNA and histone methylation, and/or acetylation. The significance of the formation of biomolecular condensates of key light signaling components is discussed and potential applications to agricultural practices overviewed

Histone Deacetylase 9 stimulates auxin-dependent thermomorphogenesis in Arabidopsis thaliana by mediating H2A.Z depletion

Many plant species respond to unfavorable high ambient temperatures by adjusting their vegetative body plan to facilitate cooling. This process is known as thermomorphogenesis and is induced by the phytohormone auxin. Here, we demonstrate that the chromatin-modifying enzyme HISTONE DEACETYLASE 9 (HDA9) mediates thermomorphogenesis but does not interfere with hypocotyl elongation during shade avoidance. HDA9 is stabilized in response to high temperature and mediates histone deacetylation at the YUCCA8 locus, a rate-limiting enzyme in auxin biosynthesis, at warm temperatures. We show that HDA9 permits net eviction of the H2A.Z histone variant from nucleosomes associated with YUCCA8, allowing binding and transcriptional activation by PHYTOCHROME INTERACTING FACTOR 4, followed by auxin accumulation and thermomorphogenesis

HISTONE DEACETYLASE 9 stimulates auxin-dependent thermomorphogenesis in Arabidopsis thaliana by mediating H2A.Z depletion

Many plant species respond to unfavorable high ambient temperatures by adjusting their vegetative body plan to facilitate cooling. This process is known as thermomorphogenesis and is induced by the phytohormone auxin. Here, we demonstrate that the chromatin-modifying enzyme HISTONE DEACETYLASE 9 (HDA9) mediates thermomorphogenesis but does not interfere with hypocotyl elongation during shade avoidance. HDA9 is stabilized in response to high temperature and mediates histone deacetylation at the YUCCA8 locus, a rate-limiting enzyme in auxin biosynthesis, at warm temperatures. We show that HDA9 permits net eviction of the H2A.Z histone variant from nucleosomes associated with YUCCA8, allowing binding and transcriptional activation by PHYTOCHROME INTERACTING FACTOR 4, followed by auxin accumulation and thermomorphogenesis