scholarly journals Phytochrome A Function in Red Light Sensing

2007 ◽  
Vol 2 (5) ◽  
pp. 383-385 ◽  
Author(s):  
Keara A. Franklin ◽  
Garry C. Whitelam
Keyword(s):  
Red Light ◽  
Phytochrome A ◽  
Light Sensing

scholarly journals Uncovering a novel function of the CCR4-NOT complex in phytochrome A-mediated light signalling in plants

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Philipp Schwenk ◽  
David J Sheerin ◽  
Jathish Ponnu ◽  
Anne-Marie Staudt ◽  
Klara L Lesch ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alternative Splicing ◽  
Growth And Development ◽  
Red Light ◽  
Negative Regulator ◽  
Potential Mechanism ◽  
Phytochrome A ◽  
Light Sensing ◽  
Light Signalling ◽  
Argonaute 1

Phytochromes are photoreceptors regulating growth and development in plants. Using the model plant Arabidopsis, we identified a novel signalling pathway downstream of the far-red light-sensing phytochrome, phyA, that depends on the highly conserved CCR4-NOT complex. CCR4-NOT is integral to RNA metabolism in yeast and animals, but its function in plants is largely unknown. NOT9B, an Arabidopsis homologue of human CNOT9, is a component of the CCR4-NOT complex, and acts as negative regulator of phyA-specific light signalling when bound to NOT1, the scaffold protein of the complex. Light-activated phyA interacts with and displaces NOT9B from NOT1, suggesting a potential mechanism for light signalling through CCR4-NOT. ARGONAUTE 1 and proteins involved in splicing associate with NOT9B and we show that NOT9B is required for specific phyA-dependent alternative splicing events. Furthermore, association with nuclear localised ARGONAUTE 1 raises the possibility that NOT9B and CCR4-NOT are involved in phyA-modulated gene expression.

Far-Red Light Blocks Greening of Arabidopsis Seedlings via a Phytochrome A: Mediated Change in Plastid Development

1996 ◽  
Vol 8 (4) ◽  
pp. 601 ◽  
Author(s):  
Simon A. Barnes ◽  
Naoko K. Nishizawa ◽  
Ronaldo B. Quaggio ◽  
Garry C. Whitelam ◽  
Nam-Hai Chua
Keyword(s):  
Red Light ◽  
Phytochrome A ◽  
Plastid Development

scholarly journals Red- and Blue-Light Sensing in the Plant Pathogen Alternaria alternata Depends on Phytochrome and the White-Collar Protein LreA

mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Olumuyiwa Igbalajobi ◽  
Zhenzhong Yu ◽  
Reinhard Fischer
Keyword(s):  
Blue Light ◽  
Alternaria Alternata ◽  
Red Light ◽  
White Collar ◽  
Nuclear Accumulation ◽  
Model Organisms ◽  
Light Induction ◽  
Content Type ◽  
High Osmolarity ◽  
Light Sensing

ABSTRACT The filamentous fungus Alternaria alternata is a common postharvest contaminant of food and feed, and some strains are plant pathogens. Many processes in A. alternata are triggered by light. Interestingly, blue light inhibits sporulation, and red light reverses the effect, suggesting interactions between light-sensing systems. The genome encodes a phytochrome (FphA), a white collar 1 (WC-1) orthologue (LreA), an opsin (NopA), and a cryptochrome (CryA) as putative photoreceptors. Here, we investigated the role of FphA and LreA and the interplay with the high-osmolarity glycerol (HOG) mitogen-activated protein (MAP) kinase pathway. We created loss-of function mutations for fphA, lreA, and hogA using CRISPR-Cas9 technology. Sporulation was reduced in all three mutant strains already in the dark, suggesting functions of the photoreceptors FphA and LreA independent of light perception. Germination of conidia was delayed in red, blue, green, and far-red light. We found that light induction of ccgA (clock-controlled gene in Neurospora crassa and light-induced gene in Aspergillus nidulans) and the catalase gene catA depended on FphA, LreA, and HogA. Light induction of ferA (a putative ferrochelatase gene) and bliC (bli-3, light regulated, unknown function) required LreA and HogA but not FphA. Blue- and green-light stimulation of alternariol formation depended on LreA. A lack of FphA or LreA led to enhanced resistance toward oxidative stress due to the upregulation of catalases and superoxide dismutases. Light activation of FphA resulted in increased phosphorylation and nuclear accumulation of HogA. Our results show that germination, sporulation, and secondary metabolism are light regulated in A. alternata with distinct and overlapping roles of blue- and red-light photosensors. IMPORTANCE Light controls many processes in filamentous fungi. The study of light regulation in a number of model organisms revealed an unexpected complexity. Although the molecular components for light sensing appear to be widely conserved in fungal genomes, the regulatory circuits and the sensitivity of certain species toward specific wavelengths seem different. In N. crassa, most light responses are triggered by blue light, whereas in A. nidulans, red light plays a dominant role. In Alternaria alternata, both blue and red light appear to be important. In A. alternata, photoreceptors control morphogenetic pathways, the homeostasis of reactive oxygen species, and the production of secondary metabolites. On the other hand, high-osmolarity sensing required FphA and LreA, indicating a sophisticated cross talk between light and stress signaling.

Dynamics of the processes leading to the acquisition of sensitivity to very low fluence of photons inDatura feroxseeds

2013 ◽  
Vol 23 (4) ◽  
pp. 233-239
Author(s):  
Gabriela Alejandra Auge ◽  
Lucila de Miguel
Keyword(s):  
Physiological State ◽  
Red Light ◽  
Light Sensitivity ◽  
Growth Potential ◽  
Soil Tillage ◽  
Phytochrome A ◽  
Light Stimulation ◽  
Endosperm Weakening ◽  
Signalling Network ◽  
Stimulation Of

AbstractSoil tillage operations stimulate germination of buried seeds in cultivated lands, allowing them to perceive light as a germination-promoting factor. The time of burial and the effect of changing environmental factors affect the physiological state of the seeds, which may lead to an extreme light-sensitivity and very low fluence response (VLFR) through phytochrome A. This paper describes the influence of the progressive process of dormancy breakage, which is accompanied by the acquisition of extreme light-sensitivity, on processes associated with endosperm weakening and embryo growth potential in the VLFR-mediated promotion ofDatura feroxseed germination. Our results show that endosperm weakening is mainly limited by β-mannosidase enzyme activity after far-red light stimulation, which is highly dependent on the dormancy level of the seeds. In addition, stimulation of the embryo growth potential by far-red irradiation did not require an extreme light-sensitivity to very low fluence of photons to reach its maximum response, and it was not completely correlated with expansin gene expression in the embryo. Our work indicates that responses of endosperm weakening and embryo growth potential to far-red irradiation, dependent on dormancy level, have different requirements for stimulation by the signalling network initiated by phytochrome A during the course of the very low fluence response inDatura feroxseeds.

Peroxisome division and proliferation in plants

2010 ◽  
Vol 38 (3) ◽  
pp. 817-822 ◽  
Author(s):  
Kyaw Aung ◽  
Xinchun Zhang ◽  
Jianping Hu
Keyword(s):  
Red Light ◽  
Specific Protein ◽  
Development Research ◽  
Phytochrome A ◽  
Division 1 ◽  
Evolutionarily Conserved ◽  
Organelle Division ◽  
Specific Factors ◽  
Related Proteins ◽  
Peroxisome Division

Peroxisomes are eukaryotic organelles with crucial functions in development. Plant peroxisomes participate in various metabolic processes, some of which are co-operated by peroxisomes and other organelles, such as mitochondria and chloroplasts. Defining the complete picture of how these essential organelles divide and proliferate will be instrumental in understanding how the dynamics of peroxisome abundance contribute to changes in plant physiology and development. Research in Arabidopsis thaliana has identified several evolutionarily conserved major components of the peroxisome division machinery, including five isoforms of PEROXIN11 proteins (PEX11), two dynamin-related proteins (DRP3A and DRP3B) and two FISSION1 proteins (FIS1A/BIGYIN and FIS1B). Recent studies in our laboratory have also begun to uncover plant-specific factors. DRP5B is a dual-localized protein that is involved in the division of both chloroplasts and peroxisomes, representing an invention of the plant/algal lineage in organelle division. In addition, PMD1 (peroxisomal and mitochondrial division 1) is a plant-specific protein tail anchored to the outer surface of peroxisomes and mitochondria, mediating the division and/or positioning of these organelles. Lastly, light induces peroxisome proliferation in dark-grown Arabidopsis seedlings, at least in part, through activating the PEX11b gene. The far-red light receptor phyA (phytochrome A) and the transcription factor HYH (HY5 homologue) are key components in this signalling pathway. In summary, pathways for the division and proliferation of plant peroxisomes are composed of conserved and plant-specific factors. The sharing of division proteins by peroxisomes, mitochondria and chloroplasts is also suggesting possible co-ordination in the division of these metabolically associated plant organelles.

scholarly journals Tips and turns of bacteriophytochrome photoactivation

2020 ◽  
Vol 19 (11) ◽  
pp. 1488-1510
Author(s):  
Heikki Takala ◽  
Petra Edlund ◽  
Janne A. Ihalainen ◽  
Sebastian Westenhoff
Keyword(s):  
Red Light ◽  
Current Understanding ◽  
Special Focus ◽  
Light Sensing

Phytochromes are red light-sensing photoreceptors. Here we review the current understanding of phytochrome photoactivation, with a special focus on bacteriophytochromes and their crystallographic studies.

scholarly journals Phosphorylation of FAR-RED ELONGATED HYPOCOTYL1 Is a Key Mechanism Defining Signaling Dynamics of Phytochrome A under Red and Far-Red Light in Arabidopsis

2012 ◽  
Vol 24 (5) ◽  
pp. 1907-1920 ◽  
Author(s):  
Fang Chen ◽  
Xiarong Shi ◽  
Liang Chen ◽  
Mingqiu Dai ◽  
Zhenzhen Zhou ◽  
...  
Keyword(s):  
Red Light ◽  
Phytochrome A ◽  
Signaling Dynamics

scholarly journals Differential responses of coral larvae to the colour of ambient light guide them to suitable settlement microhabitat

2015 ◽  
Vol 2 (10) ◽  
pp. 150358 ◽  
Author(s):  
Marie E. Strader ◽  
Sarah W. Davies ◽  
Mikhail V. Matz
Keyword(s):  
Fluorescent Protein ◽  
Critical Role ◽  
Red Light ◽  
Green Light ◽  
Ambient Light ◽  
Coral Larvae ◽  
Acropora Millepora ◽  
Light Sensing ◽  
Natal Habitat

Reef-building corals produce planktonic planula larvae that must select an appropriate habitat to settle and spend the rest of their life, a behaviour that plays a critical role in survival. Here, we report that larvae obtained from a deep-water population of Pseudodiploria strigosa settled more readily under blue light and in the dark, which aligns well with the light field characteristics of their natal habitat. By contrast, larvae of the shallow-water coral Acropora millepora settled in high proportions under blue and green light while settlement was less in the dark. Acropora millepora larvae also showed reduced settlement under red light, which should be abundant at shallow depth. Hypothesizing that this might be a mechanism preventing the larvae from settling on the exposed upwards-facing surfaces, we quantified A. millepora settlement in manipulated light chambers in situ on the reef. While A. millepora larvae naturally preferred settling on vertical rather than exposed horizontal surfaces, swapping the colours of upwards-facing and sideways-facing light fields was sufficient to invert this preference. We also tested if the variation in intrinsic red fluorescence in A. millepora larvae correlates with settlement rates, as has been suggested previously. We observed this correlation only in the absence of light, indicating that larval red fluorescent protein is probably not directly involved in light sensing. Our study reveals previously under-appreciated light-sensory capabilities in coral larvae, which could be an important axis of ecological differentiation between coral species and/or populations.

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