Light in the Fungal World: From Photoreception to Gene Transcription and Beyond

2019 ◽  
Vol 53 (1) ◽  
pp. 149-170 ◽  
Author(s):  
Luis M. Corrochano
Keyword(s):  
Blue Light ◽  
Gene Transcription ◽  
Red Light ◽  
Green Light ◽  
White Collar ◽  
Fungal Species ◽  
Signal Transduction Pathways ◽  
Fungal Biology ◽  
White Collar Complex ◽  
Effect Of Light

Fungi see light of different colors by using photoreceptors such as the White Collar proteins and cryptochromes for blue light, opsins for green light, and phytochromes for red light. Light regulates fungal development, promotes the accumulation of protective pigments and proteins, and regulates tropic growth. The White Collar complex (WCC) is a photoreceptor and a transcription factor that is responsible for regulating transcription after exposure to blue light. In Neurospora crassa, light promotes the interaction of WCCs and their binding to the promoters to activate transcription. In Aspergillus nidulans, the WCC and the phytochrome interact to coordinate gene transcription and other responses, but the contribution of these photoreceptors to fungal photobiology varies across fungal species. Ultimately, the effect of light on fungal biology is the result of the coordinated transcriptional regulation and activation of signal transduction pathways.

scholarly journals Guard cells control hypocotyl elongation through HXK1, HY5, and PIF4

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gilor Kelly ◽  
Danja Brandsma ◽  
Aiman Egbaria ◽  
Ofer Stein ◽  
Adi Doron-Faigenboim ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Blue Light ◽  
Opposite Effect ◽  
Red Light ◽  
Guard Cells ◽  
Cell Types ◽  
Hypocotyl Elongation ◽  
Sugar Production ◽  
Effect Of Light

AbstractThe hypocotyls of germinating seedlings elongate in a search for light to enable autotrophic sugar production. Upon exposure to light, photoreceptors that are activated by blue and red light halt elongation by preventing the degradation of the hypocotyl-elongation inhibitor HY5 and by inhibiting the activity of the elongation-promoting transcription factors PIFs. The question of how sugar affects hypocotyl elongation and which cell types stimulate and stop that elongation remains unresolved. We found that overexpression of a sugar sensor, Arabidopsis hexokinase 1 (HXK1), in guard cells promotes hypocotyl elongation under white and blue light through PIF4. Furthermore, expression of PIF4 in guard cells is sufficient to promote hypocotyl elongation in the light, while expression of HY5 in guard cells is sufficient to inhibit the elongation of the hy5 mutant and the elongation stimulated by HXK1. HY5 exits the guard cells and inhibits hypocotyl elongation, but is degraded in the dark. We also show that the inhibition of hypocotyl elongation by guard cells’ HY5 involves auto-activation of HY5 expression in other tissues. It appears that guard cells are capable of coordinating hypocotyl elongation and that sugar and HXK1 have the opposite effect of light on hypocotyl elongation, converging at PIF4.

scholarly journals Photosynthetic Physiology of Blue, Green, and Red Light: Light Intensity Effects and Underlying Mechanisms

2021 ◽  
Vol 12 ◽  
Author(s):  
Jun Liu ◽  
Marc W. van Iersel
Keyword(s):  
Blue Light ◽  
Interactive Effect ◽  
Red Light ◽  
Green Light ◽  
Photosynthetic Photon Flux Density ◽  
Interactive Effects ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light Spectrum ◽  
Response Curves

Red and blue light are traditionally believed to have a higher quantum yield of CO2 assimilation (QY, moles of CO2 assimilated per mole of photons) than green light, because green light is absorbed less efficiently. However, because of its lower absorptance, green light can penetrate deeper and excite chlorophyll deeper in leaves. We hypothesized that, at high photosynthetic photon flux density (PPFD), green light may achieve higher QY and net CO2 assimilation rate (An) than red or blue light, because of its more uniform absorption throughtout leaves. To test the interactive effects of PPFD and light spectrum on photosynthesis, we measured leaf An of “Green Tower” lettuce (Lactuca sativa) under red, blue, and green light, and combinations of those at PPFDs from 30 to 1,300 μmol⋅m–2⋅s–1. The electron transport rates (J) and the maximum Rubisco carboxylation rate (Vc,max) at low (200 μmol⋅m–2⋅s–1) and high PPFD (1,000 μmol⋅m–2⋅s–1) were estimated from photosynthetic CO2 response curves. Both QYm,inc (maximum QY on incident PPFD basis) and J at low PPFD were higher under red light than under blue and green light. Factoring in light absorption, QYm,abs (the maximum QY on absorbed PPFD basis) under green and red light were both higher than under blue light, indicating that the low QYm,inc under green light was due to lower absorptance, while absorbed blue photons were used inherently least efficiently. At high PPFD, the QYinc [gross CO2 assimilation (Ag)/incident PPFD] and J under red and green light were similar, and higher than under blue light, confirming our hypothesis. Vc,max may not limit photosynthesis at a PPFD of 200 μmol m–2 s–1 and was largely unaffected by light spectrum at 1,000 μmol⋅m–2⋅s–1. Ag and J under different spectra were positively correlated, suggesting that the interactive effect between light spectrum and PPFD on photosynthesis was due to effects on J. No interaction between the three colors of light was detected. In summary, at low PPFD, green light had the lowest photosynthetic efficiency because of its low absorptance. Contrary, at high PPFD, QYinc under green light was among the highest, likely resulting from more uniform distribution of green light in leaves.

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.

Chromatic adaptation in lichen phyco- and photobionts

Biologia ◽  
2010 ◽  
Vol 65 (4) ◽  
Author(s):  
Bazyli Czeczuga ◽  
Ewa Czeczuga-Semeniuk ◽  
Adrianna Semeniuk
Keyword(s):  
Photosynthetic Pigments ◽  
Light Quality ◽  
Red Light ◽  
Green Light ◽  
Total Content ◽  
Chromatic Adaptation ◽  
Xanthoria Parietina ◽  
Flavoparmelia Caperata ◽  
Peltigera Canina ◽  
Effect Of Light

AbstractThe effect of light quality on the photosynthetic pigments as chromatic adaptation in 8 species of lichens were examined. The chlorophylls, carotenoids in 5 species with green algae as phycobionts (Cladonia mitis, Hypogymnia physodes, H. tubulosa var. tubulosa and subtilis, Flavoparmelia caperata, Xanthoria parietina) and the chlorophyll a, carotenoids and phycobiliprotein pigments in 3 species with cyanobacteria as photobionts (Peltigera canina, P. polydactyla, P. rufescens) were determined. The total content of photosynthetic pigments was calculated according to the formule and particular pigments were determined by means CC, TLC, HPLC and IEC chromatography. The total content of the photosynthetic pigments (chlorophylls, carotenoids) in the thalli was highest in red light (genus Peltigera), yellow light (Xanthoria parietina), green light (Cladonia mitis) and at blue light (Flavoparmelia caperata and both species of Hypogymnia). The biggest content of the biliprotein pigments at red and blue lights was observed. The concentration of C-phycocyanin increased at red light, whereas C-phycoerythrin at green light.In Trebouxia phycobiont of Hypogymnia and Nostoc photobiont of Peltigera species the presence of the phytochromes was observed.

Photosensitivity of anthocyanin production in dark-grown and light-pretreated Zea mays seedlings

1988 ◽  
Vol 66 (6) ◽  
pp. 1021-1027 ◽  
Author(s):  
Zdenko Rengel ◽  
Herbert A. Kordan
Keyword(s):  
Zea Mays ◽  
Blue Light ◽  
White Light ◽  
Zea Mays L ◽  
Red Light ◽  
Anthocyanin Formation ◽  
Anthocyanin Production ◽  
Effect Of Light

Anthocyanin production in roots and shoots of Zea mays L. seedlings was higher in blue than in red light and was very low in far red light. Under dichromatic irradiation, a phytochrome mediation of a blue-dependent photoreaction was evident. Pretreatments with both white and blue light allowed increased anthocyanin production under subsequent inductive conditions, as did occurs in treatments with continuous blue, red, far red, or white light. It is suggested that the effect of light pretreatments on phytochrome-controlled anthocyanin formation may differ from that controlled by the combination of cryptochrome and phytochrome.

scholarly journals Transcriptomic and Metabolomic Profiling Reveals the Effect of LED Light Quality on Fruit Ripening and Anthocyanin Accumulation in Cabernet Sauvignon Grape

2021 ◽  
Vol 8 ◽  
Author(s):  
Peian Zhang ◽  
Suwen Lu ◽  
Zhongjie Liu ◽  
Ting Zheng ◽  
Tianyu Dong ◽  
...  
Keyword(s):  
Blue Light ◽  
White Light ◽  
Plant Traits ◽  
Soluble Sugars ◽  
Red Light ◽  
Green Light ◽  
Grape Berries ◽  
Light Spectra ◽  
Metabolomic Profiling ◽  
Highly Expressed Genes

Different light qualities have various impacts on the formation of fruit quality. The present study explored the influence of different visible light spectra (red, green, blue, and white) on the formation of quality traits and their metabolic pathways in grape berries. We found that blue light and red light had different effects on the berries. Compared with white light, blue light significantly increased the anthocyanins (malvidin-3-O-glucoside and peonidin-3-O-glucoside), volatile substances (alcohols and phenols), and soluble sugars (glucose and fructose), reduced the organic acids (citric acid and malic acid), whereas red light achieved the opposite effect. Transcriptomics and metabolomics analyses revealed that 2707, 2547, 2145, and 2583 differentially expressed genes (DEGs) and (221, 19), (254, 22), (189, 17), and (234, 80) significantly changed metabolites (SCMs) were filtered in the dark vs. blue light, green light, red light, and white light, respectively. According to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, most of the DEGs identified were involved in photosynthesis and biosynthesis of flavonoids and flavonols. Using weighted gene co-expression network analysis (WGCNA) of 23410 highly expressed genes, two modules significantly related to anthocyanins and soluble sugars were screened out. The anthocyanins accumulation is significantly associated with increased expression of transcription factors (VvHY5, VvMYB90, VvMYB86) and anthocyanin structural genes (VvC4H, Vv4CL, VvCHS3, VvCHI1, VvCHI2, VvDFR), while significantly negatively correlated with VvPIF4. VvISA1, VvISA2, VvAMY1, VvCWINV, VvβGLU12, and VvFK12 were all related to starch and sucrose metabolism. These findings help elucidate the characteristics of different light qualities on the formation of plant traits and can inform the use of supplemental light in the field and after harvest to improve the overall quality of fruit.

scholarly journals Effect of light quality on the cultivation of chlorella pyrenoidosa

2020 ◽  
Vol 143 ◽  
pp. 02033
Author(s):  
Hancheng Guo ◽  
Zhiguo Fang
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Blue Light ◽  
Optical Density ◽  
Light Quality ◽  
Specific Growth ◽  
Red Light ◽  
Total Lipid Content ◽  
Chlorella Pyrenoidosa ◽  
Effect Of Light

Effect of light quality, including red light, blue light, white light, red and blue mixing light with 8:1, 8:2 and 8:3, on the growth characteristics and metabolite accumulation of chlorella pyrenoidosa was conducted based on light emitting diode (LED). Results showed that chlorella pyrenoidosa grew best under blue light, and the optical density, specific growth rate and biomass of chlorella pyrenoidosa was about 2.4, 0.10 d-1 and 6.4 g·L-1, respectively, while the optical density of chlorella pyrenoidosa was between 1.0 and 1.7, specific growth rate was between 0.06-0.10 d-1 and biomass was between 2.7 and 3.8 g·L-1 under other light quality after 30 days of cultivation. The optical density, specific growth rate and biomass of chlorella pyrenoidosa was approximately 2.05 times, 1.33 times and 2.06 times under blue light than red light, respectively. Moreover, Red and blue mixing light was conducive to the synthesis of chlorophyll a and carotenoids of chlorella pyrenoidosa, and blue light could promote the synthesis of chlorophyll b. Chlorophyll a and carotenoids content of chlorella pyrenoidosa was 13.5 mg·g-1and 5.8 mg·g-1 respectively under red and blue mixing light with 8:1, while it was 8.4 mg·g-1 and 3.6 mg·g-1 respectively under blue light. Red and blue mixing light was more conducive to protein and total lipid content per dry cell of chlorella pyrenoidosa. Protein and total lipid content was 489.3 mg·g-1 and 311.2 mg·g-1 under red and blue mixing light with 8:3, while it was 400.9 mg·g-1 and 231.9 mg·g-1 respectively under blue light.

Control by Light Quality of Chlorophyll Synthesis in the Brown Alga Desmarestia aculeata

1991 ◽  
Vol 46 (7-8) ◽  
pp. 542-548 ◽  
Author(s):  
F. López-Figueroa
Keyword(s):  
Blue Light ◽  
Light Quality ◽  
Red Light ◽  
Green Light ◽  
Chlorophyll Synthesis ◽  
Natural Conditions ◽  
Light Pulses ◽  
Light Effects ◽  
Starvation Conditions

Abstract The chlorophyll synthesis in the brown algae Desmarestia aculeata is affected by light quality and by the nutrient state in the medium before the illumination. Pulses of 5 min of red, green and blue light together with 200 μM nitrate in plants growing under natural conditions deter­ mined similar induction of chlorophyll synthesis. However, when the plants were incubated previously under starvation conditions the light effect was different. The induction of chlorophyll synthesis was greater after blue and green light than after red light pulses. Red-light photoreceptor was only involved in the chlorophyll synthesis under no nutrient limitations and under starvation conditions after previous illumination with blue light followed by far-red light. The induction of chlorophyll synthesis by green and blue light pulses applied together with nitrate was greater when the algae were incubated in starvation conditions than in natural conditions (normal nutrient state). Because all light effects were partially reversed by far-red light the involvement of a phyto-chrome-like photoreceptor is proposed. In addition, a coaction between blue-and a green-light photoreceptors and phytochrome is suggested.

scholarly journals Dual and Multi-Emission Hybrid Micelles Realized through Coordination-Driven Self-Assembly

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 440
Author(s):  
Youxiong Zheng ◽  
Yan Tang ◽  
Jianwei Yu ◽  
Lan Xie ◽  
Huiyou Dong ◽  
...  
Keyword(s):  
Blue Light ◽  
White Light ◽  
Self Assembly ◽  
Light Emission ◽  
Raft Polymerization ◽  
Red Light ◽  
Green Light ◽  
Assembly Process ◽  
Blue Light Emission ◽  
Dual Emission

Building novel functional nanomaterials with a polymer is one of the most dynamic research fields at present. Here, three amphiphilic block copolymers of 8-hydroxyquinoline derivative motifs (MQ) with excellent coordination function were synthesized by Reversible Addition-Fragmentation Chain Transfer Polymerization (RAFT) polymerization. The coordination micelles were prepared through the self-assembly process, which the MQ motifs were dispersed in the hydrophobic polystyrene (PSt) blocks and hydrophilic Poly(N-isopropylacrylamide (PNIPAM)) blocks, respectively. The dual-emission micelles including the intrinsic red light emission of quantum dots (QDs) and the coordination green light emission of Zn2+-MQ complexes were built by introducing the CdSe/ZnS and CdTe/ZnS QDs in the core and shell precisely in the coordination micelles through the coordination-driven self-assembly process. Furthermore, based on the principle of three primary colors that produce white light emission, vinyl carbazole units (Polyvinyl Carbazole, PVK) with blue light emission were introduced into the hydrophilic PNIPAM blocks to construct the white light micelles that possess special multi-emission properties in which the intrinsic red light emission of QDs, the coordination green light of Zn2+-MQ complexes, and the blue light emission of PVK were synergized. The dual and multi-emission hybrid micelles have great application prospects in ratiometric fluorescent probes and biomarkers.

scholarly journals Green Light Improves Photosystem Stoichiometry in Cucumber Seedlings (Cucumis sativus) Compared to Monochromatic Red Light

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 824
Author(s):  
Nicholas B. Claypool ◽  
J. Heinrich Lieth
Keyword(s):  
Leaf Area ◽  
Cucumis Sativus ◽  
Blue Light ◽  
Quantum Efficiency ◽  
Photosynthetic Capacity ◽  
Red Light ◽  
Green Light ◽  
Photosynthetic Performance ◽  
Cucumber Seedlings ◽  
Light Enhancement

It has been shown that monochromatic red and blue light influence photosynthesis and morphology in cucumber. It is less clear how green light impacts photosynthetic performance or morphology, either alone or in concert with other wavelengths. In this study, cucumber (Cucumis sativus) was grown under monochromatic blue, green, and red light, dichromatic blue–green, red–blue, and red–green light, as well as light containing red, green, and blue wavelengths, with or without supplemental far-red light. Photosynthetic data collected under treatment spectra at light-limiting conditions showed that both red and green light enhance photosynthesis. However, photosynthetic data collected with a 90% red, 10% blue, 1000 µmol photons m−2 s−1, saturating light show significantly lower photosynthesis in the green, red, and red–green treatments, indicating a blue light enhancement due to photosystem stoichiometric differences. The red–green and green light treatments show improved photosynthetic capacity relative to red light, indicating partial remediation by green light. Despite a lower quantum efficiency and the lowest ambient photosynthesis levels, the monochromatic blue treatment produced among the tallest, most massive plants with the greatest leaf area and thickest stems.

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