Antagonistic actions of Arabidopsis cryptochromes and phytochrome B in the regulation of floral induction

Development ◽  
1999 ◽  
Vol 126 (10) ◽  
pp. 2073-2082 ◽  
Author(s):  
T.C. Mockler ◽  
H. Guo ◽  
H. Yang ◽  
H. Duong ◽  
C. Lin
Keyword(s):  
Flowering Time ◽  
Blue Light ◽  
Molecular Mechanisms ◽  
Light Quality ◽  
Floral Induction ◽  
Red Light ◽  
Floral Initiation ◽  
Sensitive Phase ◽  
Light Inhibition

The Arabidopsis photoreceptors cry1, cry2 and phyB are known to play roles in the regulation of flowering time, for which the molecular mechanisms remain unclear. We have previously hypothesized that phyB mediates a red-light inhibition of floral initiation and cry2 mediates a blue-light inhibition of the phyB function. Studies of the cry2/phyB double mutant provide direct evidence in support of this hypothesis. The function of cryptochromes in floral induction was further investigated using the cry2/cry1 double mutants. The cry2/cry1 double mutants showed delayed flowering in monochromatic blue light, whereas neither monogenic cry1 nor cry2 mutant exhibited late flowering in blue light. This result suggests that, in addition to the phyB-dependent function, cry2 also acts redundantly with cry1 to promote floral initiation in a phyB-independent manner. To understand how photoreceptors regulate the transition from vegetative growth to reproductive development, we examined the effect of sequential illumination by blue light and red light on the flowering time of plants. We found that there was a light-quality-sensitive phase of plant development, during which the quality of light exerts a profound influence on flowering time. After this developmental stage, which is between approximately day-1 to day-7 post germination, plants are committed to floral initiation and the quality of light has little effect on the flowering time. Mutations in either the PHYB gene or both the CRY1 and CRY2 genes resulted in the loss of the light-quality-sensitive phase manifested during floral development. The commitment time of floral transition, defined by a plant's sensitivity to light quality, coincides with the commitment time of inflorescence development revealed previously by a plant's sensitivity to light quantity - the photoperiod. Therefore, the developmental mechanism resulting in the commitment to flowering appears to be the direct target of the antagonistic actions of the photoreceptors.

scholarly journals Ginkgo biloba L. Responds to Red and Blue Light: Via Phenylpropanoid and Flavonoid Biosynthesis Pathway

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1079
Author(s):  
Lei Zhang ◽  
Gaiping Wang ◽  
Guibin Wang ◽  
Fuliang Cao
Keyword(s):  
Blue Light ◽  
Ginkgo Biloba ◽  
Metabolic Pathways ◽  
Transcriptome Sequencing ◽  
Molecular Mechanisms ◽  
Light Quality ◽  
Red Light ◽  
Enrichment Analysis ◽  
Flavonoid Biosynthesis ◽  
Sequencing Analysis

Light quality is a key environmental factor affecting plant growth and development. In this study, RNA-seq technology was used to explore the molecular mechanisms of ginkgo metabolism under different monochromatic lights. Leaves were used for transcriptome sequencing analysis after being irradiated by red, blue, and white LED lights. After treatment, 2040 differentially expressed genes (DEGs) were identified. Gene Ontology (GO) analysis showed that the DEGs were annotated into 49 terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that 736 DEGs were enriched in 100 metabolic pathways, and 13 metabolic pathways were significantly enriched, especially ‘phenylpropanoid biosynthesis’ and ‘flavonoid biosynthesis’. Further analysis of DEGs expression in the two pathways showed that Ginkgo biloba adapts to blue light mainly by promoting the expression of GbFLS to synthesize quercetin, kaempferol, and myncetin, and adapts to red light by promoting the expression of GbDFR to synthesize leucocyanidin. Nine DEGs were randomly selected for qRT-PCR verification, and the gene expression results were consistent with that of transcriptome sequencing. In conclusion, this study is the first to explore the molecular mechanism of ginkgo in response to different monochromatic lights, and it will lay a foundation for the research and application of light quality in the cultivation of leaf-use G. biloba.

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.

THE EFFECT OF LIGHT QUALITY ON THE PRODUCTS OF PHOTOSYNTHESIS IN CHLORELLA VULGARIS

1962 ◽  
Vol 40 (1) ◽  
pp. 179-189 ◽  
Author(s):  
A. H. W. Hauschild ◽  
C. D. Nelson ◽  
G. Krotkov
Keyword(s):  
Blue Light ◽  
Chlorella Vulgaris ◽  
Glycolic Acid ◽  
Light Quality ◽  
Soluble Fraction ◽  
Red Light ◽  
Total Radioactivity ◽  
Rate Of Photosynthesis ◽  
Effect Of Light

Suspensions of Chlorella vulgaris, grown in synchronous culture, were pretreated in darkness for 45 to 225 minutes and illuminated in the presence of C14-bicarbonate with red, with red plus 4% of blue, and with blue light alone. The light intensities were so adjusted that the rate of photosynthesis (fixation of C14) was the same under the different conditions of illumination. The distribution of C14 among the various compounds of the ethanol-soluble fraction was obtained using paper chromatography and autoradiography.After 5 minutes of photosynthesis, the incorporation of C14 into aspartic acid was higher in the presence of red with supplementary blue light than in red light alone. At the same time the total radioactivity in glycine plus serine and in glycolic acid decreased. After 30 minutes of photosynthesis, blue light supplementary to red and blue light alone increased the total incorporation of C14 into the amino acid plus organic acid fraction as compared with incorporation in red light. This was due mainly to an increase in the radioactivity of aspartic and glutamic acids, while at the same time the radioactivity in glycine and glycolic acid was reduced.The duration of dark pretreatment was an important factor in the 30-minute experiments. The effect of increased dark pretreatment was to lower the incorporation of C14 into aspartic and glutamic acids when photosynthesis was carried out in red light, but the incorporation of C14 into these acids was increased in the presence of supplementary blue light.It is concluded that the distribution of carbon among the products of photosynthesis is affected by the quality of light.

The influence of red and blue light on the rate of photosynthesis and the CO2 compensation point at various oxygen concentrations

1970 ◽  
Vol 48 (6) ◽  
pp. 1251-1257 ◽  
Author(s):  
N. P. Voskresenskaya ◽  
G. S. Grishina ◽  
S. N. Chmora ◽  
N. M. Poyarkova
Keyword(s):  
Nicotiana Tabacum ◽  
Blue Light ◽  
Photosynthetic Rate ◽  
Prolonged Exposure ◽  
Red Light ◽  
Compensation Point ◽  
Gas Analyzer ◽  
Co2 Compensation Point ◽  
Rate Of Photosynthesis ◽  
Light Inhibition

Apparent photosynthesis of attached leaves of Phaseolus vulgaris, Vicia faba, Pisum sativum, and Nicotiana tabacum at various intensities of blue and red light was measured by infrared CO2 gas analyzer in a closed system. Simultaneously the CO2 compensation point was measured.It was found that light-limited photosynthetic rate in blue light was equal to or more than that in red light. Inhibition of photosynthesis, which sometimes occurred at light-saturated intensities of blue light, could be avoided by addition of red light, prolonged exposure of the plants to blue light, or by lowering the O2 concentration. Accordingly, the increase of photosynthetic rate due to change of O2 concentration from 21 to 3% O2 is higher in blue light only when photosynthesis is inhibited by blue light at 21% O2. The data on the action of blue and red light on the CO2 compensation point seems to exclude the activation of photorespiration by blue light.The possible effects of blue light on apparent photosynthesis are discussed on the basis of the results presented.

ScFT6: A Putative Candidate for Sugarcane Floral Inducer

2021 ◽  
Author(s):  
Manoel Viana Linhares-Neto ◽  
Pedro Vitor Schumacher ◽  
Thales Henrique Cherubino Ribeiro ◽  
Carlos Henrique Cardon ◽  
Pâmela Marinho Resende ◽  
...  
Keyword(s):  
Flowering Time ◽  
Regulatory Networks ◽  
Floral Induction ◽  
Orthologous Gene ◽  
Time Behavior ◽  
Variable Expression ◽  
Binding Protein Gene ◽  
Sugarcane Productivity ◽  
Phosphatidylethanolamine Binding Protein

Abstract One of the factors that can decrease sugarcane productivity is the flowering, because it affects the quantity and quality of feedstock, due to sucrose consumption from the stem during inflorescence emission. Photoperiodicity is the main environmental factor involved in sugarcane floral induction, which occurs by the integration of gene regulatory networks in response to environmental and endogenous stimuli. One of the genes involved in those regulatory networks is the FLOWERING LOCUS T (FT), which is considered a phloem-mobile signal that stimulates floral induction in the shoot apical meristem. This work aimed to identify and characterize homologs of the FT gene in sugarcane, as well as to determine the putative function of these genes during floral induction. From this perspective, we have conducted in silico analyses of putative FT orthologs in sugarcane, as well as the expression levels in different photoperiodic conditions in a 24-hours-day-cycle of ScFT6 in different plant tissues in contrasting cultivars in terms of flowering time. Three new possible FT orthologs were found with high similarity to FT homologs in other species. Among three genes identified, we highlighted ScFT6, which has a conserved domain and amino acids at characteristic positions for the flowering inducer phosphatidylethanolamine-binding protein gene family. Additionally, its expression occurs according to coincidental model, possibly being controlled by the circadian clock. Cultivars with distinct flowering time behavior display variable expression for the ScFT6 gene, suggesting a possible genotypic relationship for its expression. Therefore, sugarcane has at least one putative orthologous gene in relation to FT that promotes floral induction.

scholarly journals Identification and expression of the trehalose-6-phosphate synthase gene family members in tomato exposed to different light spectra

2017 ◽  
Vol 69 (1) ◽  
pp. 93-101
Author(s):  
Zexiong Chen ◽  
Juan Lou
Keyword(s):  
Plant Growth ◽  
Blue Light ◽  
White Light ◽  
Growth And Development ◽  
Light Quality ◽  
Red Light ◽  
Floral Transition ◽  
Stem Length ◽  
Pcr Analysis ◽  
Phosphate Synthase

Light is the source of energy for plants. Light wavelengths, densities and irradiation periods act as signals directing morphological and physiological characteristics during plant growth and development. To evaluate the effects of light wavelengths on tomato growth and development, Solanum lycopersicum (cv. micro-Tom) seedlings were exposed to different light-quality environments, including white light and red light supplemented with blue light (at ratios of 3:1 and 8;1, respectively). Tomatoes grown under red light supplemented with blue light displayed significantly shorter stem length, a higher number of flower buds and rate of fruit set, but an extremely late flowering compared to white-light-grown plants. To illustrate the mechanism underlying the inhibition of stem growth and floral transition mediated by red/blue light, 10 trehalose-6-phosphate synthase (TPS) genes were identified in tomato, and bioinformatics analysis was performed. qRT-PCR analysis showed that SlTPSs were expressed widely throughout plant development and SlTPS1 was expressed at extremely high levels in stems and buds. Further analysis of several flowering-associated genes and microRNAs showed that the expressions of SlTPS1, SlFT and miR172 were significantly downregulated in tomato grown under red and blue light compared with those grown under white light, whereas miR156 transcript levels were increased. A regulatory model underlying vegetative growth and floral transition regulated by light qualities is presented. Our data provide evidence that light quality strongly affects plant growth and phase transition, most likely via the TPS1-T6P signaling pathway.

scholarly journals Interactive Effects of Light Quality and Temperature on Arabidopsis Growth and Immunity

2020 ◽  
Vol 61 (5) ◽  
pp. 933-941
Author(s):  
Xiaoying Liu ◽  
Chunmei Xue ◽  
Le Kong ◽  
Ruining Li ◽  
Zhigang Xu ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Blue Light ◽  
Light Quality ◽  
Red Light ◽  
Complex Interaction ◽  
Hypocotyl Elongation ◽  
Interactive Effects ◽  
Phytochrome B ◽  
Light Conditions ◽  
Effects Of Temperature

Abstract We report here the interactive effects of three light qualities (white, red and blue) and three growth temperatures (16�C, 22�C and 28�C) on rosette growth, hypocotyl elongation and disease resistance in Arabidopsis thaliana. While an increase in temperature promotes hypocotyl elongation irrespective of light quality, the effects of temperature on rosette growth and disease resistance are dependent on light quality. Maximum rosette growth rate under white, red and blue light are observed at 28�C, 16�C and 22�C, respectively. The highest disease resistance is observed at 16�C under all three light conditions, but the highest susceptibility is observed at 28�C for white light and 22�C for red and blue light. Interestingly, rosette growth is inhibited by phytochrome B (PHYB) under blue light at 28�C and by cryptochromes (CRYs) under red light at 16�C. In addition, disease resistance is inhibited by PHYB under blue light and promoted by CRYs under red light. Therefore, this study reveals a complex interaction between light and temperature in modulating rosette growth and disease resistance as well as the contribution of PHYB and CRY to disease resistance.

Light quality of continuous illuminating at night to induce floral initiation of Fragaria chiloensis L. CHI-24-1

2006 ◽  
Vol 109 (4) ◽  
pp. 309-314 ◽  
Author(s):  
Tomohiro Yanagi ◽  
Takanori Yachi ◽  
Nobuaki Okuda ◽  
Kensyo Okamoto
Keyword(s):  
Light Quality ◽  
Floral Initiation ◽  
Fragaria Chiloensis

scholarly journals The role of far-red light (FR) in photomorphogenesis and its use in greenhouse plant production

2020 ◽  
Vol 116 (1) ◽  
pp. 93
Author(s):  
Bojka KUMP
Keyword(s):  
Growth And Development ◽  
Light Quality ◽  
Red Light ◽  
Spectral Composition ◽  
Plant Production ◽  
Recent Developments ◽  
Long Time ◽  
Supplementary Lighting ◽  
Quality Of Products

<p>Light energy is one of the most important factors regulating the growth and development of plants. In greenhouses and other controlled- environments in which the natural radiation intensities are often low, plant production relies on supplementary lighting to optimize the photosynthesis, increase production levels, and enable year-round production. For a long time, the research related to artificial lighting sources focused on the optimization of the efficiency of use for photosynthesis. The quality of light in plant production has been widely addressed only recently with the development of advanced LED technology that is energy efficient and enables the control of the spectral composition of light. Red and far-red light are sensed by the phytochromes that trigger several morphological and developmental processes that impact productivity and yield quality. Thus, to efficiently exploit all the advantages of LEDs and to develop LED arrays for specific plant applications, it is essential to understand thoroughly how light quality influences plant growth and development. This paper presents an overview of the recent developments in light quality manipulation, focusing on far-red light and the R: FR ratio, to improve yield and quality of products and to manage plant architecture and flowering in vegetable and ornamental horticulture.</p>

scholarly journals Growth and Acclimation of In Vitro-Propagated M9 Apple Rootstock Plantlets under Various Visible Light Spectrums

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1017
Author(s):  
Guem-Jae Chung ◽  
Jin-Hui Lee ◽  
Myung-Min Oh
Keyword(s):  
Stomatal Conductance ◽  
Blue Light ◽  
Photosynthetic Rate ◽  
Light Quality ◽  
Red Light ◽  
High Ratio ◽  
The Other ◽  
Ex Vitro ◽  
Apple Rootstock

This study aimed to explore the suitable light quality condition for ex vitro acclimation of M9 apple plantlets. Light quality treatments were set as followed; monochromatic LEDs (red (R), green (G), blue (B)) and polychromatic LEDs (R:B = 7:3, 8:2 and 9:1; R:G:B = 6:1:3, 7:1:2 and 8:1:1). Plant height of R, R9B1, and R8G1B1 treatments were significantly higher than the other treatments. The number of leaves and SPAD value of B were significantly higher than the other treatments. Root fresh weights of R9B1 and R7G1B2 treatments showed an increase of at least 1.7-times compared to R, G and R8B2. R8G1B1 accumulated higher starch contents than the other treatments. Photosynthetic rate of R9B1 and R8B2 were significantly higher than the other treatments. In terms of stomatal conductance and transpiration rate, treatments with high blue ratio such as B, R7B3 had higher values. Rubisco concentration was high in R and B among monochromatic treatments. In conclusion, red light was effective to increase photosynthetic rate and biomass and blue light increased chlorophyll content and stomatal conductance. Therefore, for R9B1 and R8G1B1, a mixture of high ratio of red light with a little blue light would be proper for the acclimation of in vitro-propagated apple rootstock M9 plantlets to an ex vitro environment.

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