scholarly journals A high-throughput delayed fluorescence method reveals underlying differences in the control of circadian rhythms inTriticum aestivumandBrassica napus

2019 ◽  
Author(s):  
Hannah Rees ◽  
Susan Duncan ◽  
Peter Gould ◽  
Rachel Wells ◽  
Mark Greenwood ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
High Throughput ◽  
Delayed Fluorescence ◽  
Crop Plants ◽  
Growth And Yield ◽  
Constant Darkness ◽  
Competitive Growth ◽  
Representative Sampling ◽  
Circadian Control ◽  
Wide Range

AbstractBackgroundA robust circadian clock has been implicated in plant resilience, resource-use efficiency, competitive growth and yield. A huge number of physiological processes are under circadian control in plants including: responses to biotic and abiotic stresses; flowering time; plant metabolism; and mineral uptake. Understanding how the clock functions in crops such asTriticum aestivum(bread wheat) andBrassica napus(oilseed rape) therefore has great agricultural potential. Delayed fluorescence (DF) imaging has been shown to be applicable to a wide range of plant species and requires no genetic transformation. Although DF has been used to measure period length of both mutants and wild ecotypes ofArabidopsis, this assay has never been systematically optimised for crop plants. The physical size of bothB. napusandT. aestivumled us to develop a representative sampling strategy which enables high-throughput imaging of these crops.ResultsIn this study, we describe the plant-specific optimisation of DF imaging to obtain reliable circadian phenotypes with the robustness and reproducibility to detect diverging periods between cultivars of the same species. We find that the age of plant material, light regime and temperature conditions all significantly effect DF rhythms and describe the optimal conditions for measuring robust rhythms in each species. We also show that sections of leaf can be used to obtain period estimates with improved throughput for larger sample size experiments.ConclusionsWe present an optimized protocol for high-throughput phenotyping of circadian period specific to two economically valuable crop plants. Application of this method revealed significant differences between the periods of several widely grown elite cultivars. This method also identified intriguing differential responses of circadian rhythms inT. aestivumcompared toB. napus; specifically the dramatic change to rhythm robustness when plants were imaged under constant light versus constant darkness. This points towards diverging networks underling circadian control in these two species.

scholarly journals Post-Translational Mechanisms of Plant Circadian Regulation

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 325
Author(s):  
Jiapei Yan ◽  
Yeon Jeong Kim ◽  
David E. Somers
Keyword(s):  
Circadian Rhythms ◽  
Recent Work ◽  
Transcriptional Control ◽  
Circadian System ◽  
Circadian Oscillator ◽  
Circadian Regulation ◽  
Circadian Control ◽  
Wide Range ◽  
Molecular Components ◽  
Translational Mechanisms

The molecular components of the circadian system possess the interesting feature of acting together to create a self-sustaining oscillator, while at the same time acting individually, and in complexes, to confer phase-specific circadian control over a wide range of physiological and developmental outputs. This means that many circadian oscillator proteins are simultaneously also part of the circadian output pathway. Most studies have focused on transcriptional control of circadian rhythms, but work in plants and metazoans has shown the importance of post-transcriptional and post-translational processes within the circadian system. Here we highlight recent work describing post-translational mechanisms that impact both the function of the oscillator and the clock-controlled outputs.

scholarly journals Body Temperature and Activity Rhythms Under Different Photoperiods in High Arctic Svalbard ptarmigan (Lagopus muta hyperborea)

2021 ◽  
Vol 12 ◽  
Author(s):  
Daniel Appenroth ◽  
Andreas Nord ◽  
David G. Hazlerigg ◽  
Gabriela C. Wagner
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Core Body Temperature ◽  
High Arctic ◽  
The Arctic ◽  
Constant Darkness ◽  
Polar Regions ◽  
Circadian Control ◽  
Polar Day ◽  
Lagopus Muta

Organisms use circadian rhythms to anticipate and exploit daily environmental oscillations. While circadian rhythms are of clear importance for inhabitants of tropic and temperate latitudes, its role for permanent residents of the polar regions is less well understood. The high Arctic Svalbard ptarmigan shows behavioral rhythmicity in presence of light-dark cycles but is arrhythmic during the polar day and polar night. This has been suggested to be an adaptation to the unique light environment of the Arctic. In this study, we examined regulatory aspects of the circadian control system in the Svalbard ptarmigan by recording core body temperature (Tb) alongside locomotor activity in captive birds under different photoperiods. We show that Tb and activity are rhythmic with a 24-h period under short (SP; L:D 6:18) and long photoperiod (LP; L:D 16:8). Under constant light and constant darkness, rhythmicity in Tb attenuates and activity shows signs of ultradian rhythmicity. Birds under SP also showed a rise in Tb preceding the light-on signal and any rise in activity, which proves that the light-on signal can be anticipated, most likely by a circadian system.

Novel thermally activated delayed fluorescence materials by high-throughput virtual screening: going beyond donor–acceptor design

2021 ◽  
Vol 9 (9) ◽  
pp. 3324-3333 ◽  
Author(s):  
Ke Zhao ◽  
Ömer H. Omar ◽  
Tahereh Nematiaram ◽  
Daniele Padula ◽  
Alessandro Troisi
Keyword(s):  
Virtual Screening ◽  
Quantum Chemistry ◽  
High Throughput ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Quantum Chemistry Calculations ◽  
Donor Acceptor ◽  
Molecular Semiconductors ◽  
High Throughput Virtual Screening

125 potential TADF candidates are identified through quantum chemistry calculations of 700 molecules derived from a database of 40 000 molecular semiconductors. Most of them are new and some do not belong to the class of donor–acceptor molecules.

scholarly journals Solution-Processed OLEDs Based on Thermally Activated Delayed Fluorescence Copper(I) Complexes with Intraligand Charge-Transfer Excited State

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1125
Author(s):  
Teng Teng ◽  
Jinfan Xiong ◽  
Gang Cheng ◽  
Changjiang Zhou ◽  
Xialei Lv ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Density Functional ◽  
Delayed Fluorescence ◽  
Quantum Yields ◽  
Functional Theory ◽  
Solution Processed ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Wide Range

A new series of tetrahedral heteroleptic copper(I) complexes exhibiting efficient thermally-activated delayed fluorescence (TADF) in green to orange electromagnetic spectral regions has been developed by using D-A type N^N ligand and P^P ligands. Their structures, electrochemical, photophysical, and electroluminescence properties have been characterized. The complexes exhibit high photoluminescence quantum yields (PLQYs) of up to 0.71 at room temperature in doped film and the lifetimes are in a wide range of 4.3–24.1 μs. Density functional theory (DFT) calculations on the complexes reveal the lowest-lying intraligand charge-transfer excited states that are localized on the N^N ligands. Solution-processed organic light emitting diodes (OLEDs) based on one of the new emitters show a maximum external quantum efficiency (EQE) of 7.96%.

Disrupted circadian rhythms in VIP- and PHI-deficient mice

2003 ◽  
Vol 285 (5) ◽  
pp. R939-R949 ◽  
Author(s):  
Christopher S. Colwell ◽  
Stephan Michel ◽  
Jason Itri ◽  
Williams Rodriguez ◽  
J. Tam ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Wheel Running ◽  
Activity Rhythm ◽  
Activity Patterns ◽  
Circadian System ◽  
Diurnal Rhythms ◽  
Constant Darkness ◽  
Light Cycle ◽  
Wild Type ◽  
Deficient Mice

The related neuropeptides vasoactive intestinal peptide (VIP) and peptide histidine isoleucine (PHI) are expressed at high levels in the neurons of the suprachiasmatic nucleus (SCN), but their function in the regulation of circadian rhythms is unknown. To study the role of these peptides on the circadian system in vivo, a new mouse model was developed in which both VIP and PHI genes were disrupted by homologous recombination. In a light-dark cycle, these mice exhibited diurnal rhythms in activity which were largely indistinguishable from wild-type controls. In constant darkness, the VIP/PHI-deficient mice exhibited pronounced abnormalities in their circadian system. The activity patterns started ∼8 h earlier than predicted by the previous light cycle. In addition, lack of VIP/PHI led to a shortened free-running period and a loss of the coherence and precision of the circadian locomotor activity rhythm. In about one-quarter of VIP/PHI mice examined, the wheel-running rhythm became arrhythmic after several weeks in constant darkness. Another striking example of these deficits is seen in the split-activity patterns expressed by the mutant mice when they were exposed to a skeleton photoperiod. In addition, the VIP/PHI-deficient mice exhibited deficits in the response of their circadian system to light. Electrophysiological analysis indicates that VIP enhances inhibitory synaptic transmission within the SCN of wild-type and VIP/PHI-deficient mice. Together, the observations suggest that VIP/PHI peptides are critically involved in both the generation of circadian oscillations as well as the normal synchronization of these rhythms to light.

scholarly journals Cryptochromes regulate IGF-1 production and signaling through control of JAK2-dependent STAT5B phosphorylation

2017 ◽  
Vol 28 (6) ◽  
pp. 834-842 ◽  
Author(s):  
Amol Chaudhari ◽  
Richa Gupta ◽  
Sonal Patel ◽  
Nikkhil Velingkaar ◽  
Roman Kondratov
Keyword(s):  
Circadian Rhythms ◽  
Circadian Clock ◽  
Skeletal Muscles ◽  
Cancer Metabolism ◽  
Reduced Body ◽  
Circadian Control ◽  
Cell Growth And Proliferation ◽  
Deficient Mice ◽  
Igf Signaling

Insulin-like growth factor (IGF) signaling plays an important role in cell growth and proliferation and is implicated in regulation of cancer, metabolism, and aging. Here we report that IGF-1 level in blood and IGF-1 signaling demonstrates circadian rhythms. Circadian control occurs through cryptochromes (CRYs)—transcriptional repressors and components of the circadian clock. IGF-1 rhythms are disrupted in Cry-deficient mice, and IGF-1 level is reduced by 80% in these mice, which leads to reduced IGF signaling. In agreement, Cry-deficient mice have reduced body (∼30% reduction) and organ size. Down-regulation of IGF-1 upon Cry deficiency correlates with reduced Igf-1 mRNA expression in the liver and skeletal muscles. Igf-1 transcription is regulated through growth hormone–induced, JAK2 kinase–mediated phosphorylation of transcriptional factor STAT5B. The phosphorylation of STAT5B on the JAK2-dependent Y699 site is significantly reduced in the liver and skeletal muscles of Cry-deficient mice. At the same time, phosphorylation of JAK2 kinase was not reduced upon Cry deficiency, which places CRY activity downstream from JAK2. Thus CRYs link the circadian clock and JAK-STAT signaling through control of STAT5B phosphorylation, which provides the mechanism for circadian rhythms in IGF signaling in vivo.

Radiation absorption, growth and yield of cereals

1978 ◽  
Vol 91 (1) ◽  
pp. 47-60 ◽  
Author(s):  
J. N. Gallagher ◽  
P. V. Biscoe
Keyword(s):  
Dry Matter ◽  
Growing Season ◽  
Growth Efficiency ◽  
Growth And Yield ◽  
Radiation Absorption ◽  
Exponential Equation ◽  
Crop Cover ◽  
Crop Growth Rate ◽  
Wide Range ◽  
Total Crop

SummaryAnalysis of measurements of absorbed radiation and leaf area indices of wheat and barley crops showed that throughout most of growth the fraction of absorbed solar radiation could be described by a simple exponential equation.For several of these crops grown under a wide range of weather and husbandry at Sutton Bonington and Rothamsted, 2-weekly values of crop growth rate (C) were closely related to radiation absorbed until ear emergence and about 3·0 g of dry matter (D.M.) were produced by each MJ of photosynthetically active radiation (PAR) absorbed. Final crop weight was closelyrelated to total PAR absorbed during growth (SA); on average about 2·2 g D.M. were produced per MJ absorbed, equivalent to a growth efficiency (Eg) of approximately 3·9%. Unfertilized and drought-stressed crops had a smaller Eg.The fraction of total crop D.M. harvested as grain (harvest index) varied more for wheat than for barley. Calculations of a maximum realizable grain yield made using the largest values of Eg and SA for the crops measured and assuming a harvestindex of 0.53 (achieved in an experimental crop) showed a grain D.M. yield of 10·3 t D.M./ha to be possible. To achieve such a yield would require full crop cover from the beginning of April until the end of July in a typical English growing season.

The Effect of Pruning and Several Kinds of Growing Media Fertigation Hydroponic Systems Against Protection and Production of Melons (Cucumis Melo L.)

Nabatia ◽  
2016 ◽  
Vol 4 (2) ◽  
pp. 57-63
Author(s):  
M Abror ◽  
M Koko Ardiansyah
Keyword(s):  
Plant Height ◽  
Cucumis Melo ◽  
Fruit Weight ◽  
Growth And Yield ◽  
Leaf Number ◽  
Growing Media ◽  
Hydroponic System ◽  
Wide Range ◽  
Number Of Leaves ◽  
Cucumis Melo L

This study aims to determine the effect of trimming with a wide variety of growing media hydroponic system fertigation on growth and yield of melon. Research will be conducted in the green house (House of plastic) UMSIDA Agriculture Faculty, Campus 2, Gelam, Candi, Sidoarjo, research time between the months of March to June 2016 using analysis of variance and continued test HSD 5%. The variables measured were plant height, leaf number, level of sweetness of fruit, fruit weight, high-fruit, thickness of the flesh of the fruit, conclusion from this research is going on the effect of trimming and a wide variety of growing media hydroponic system fertigation in treatment PM5 (trimming down, kokopit). There was also a real influence on the treatment PM6 (without pruning, kokopit) .In observation of plant height, leaf number, fruit weight, and high fruit. And also happens to influence a wide range of growing media on growth and yield of melon on hydroponics fertigation system, the PM6 treatment (without pruning, kokopit) had the highest rates in the observation of plant height, weight of the fruit, and the number of leaves.

Pythium intermedium. [Descriptions of Fungi and Bacteria].

1964 ◽  
Author(s):  
G. M. Waterhouse
Keyword(s):  
North America ◽  
South America ◽  
Geographical Distribution ◽  
Root Rot ◽  
Crop Plants ◽  
Foot Rot ◽  
Damping Off ◽  
Wide Range

Abstract A description is provided for Pythium intermedium. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide range of hosts represented by the following families: Begoniaceae, Bromeliaceae, Chenopodiaceae, Compositae, Coniferae, Cruciferae, Euphorbiaceae, Geraniaceae, Gramineae, Leguminosae, Liliaceae, Linaceae, Moraceae, Onagraceae, Ranunculaceae, Rosaceae, Solanaceae, Ulmaceae, Violaceae; also in the Equisetales and Filicales. DISEASES: Damping-off of seedlings, foot rot and root rot of ornamentals, occasionally of crop plants and trees. GEOGRAPHICAL DISTRIBUTION: Asia (China); Australia & Oceania (Hawaii); Europe (England, Belgium, France, Germany, Holland, Sweden, U.S.S.R.); North America (U.S.A.); South America (Argentina). TRANSMISSION: A common soil inhabitant.

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