scholarly journals The Circadian Rhythm of Leaf Movement of Coleus blumei x C. frederici, a Short Day Plant. I. Under Constant Light Conditions

1968 ◽  
Vol 43 (12) ◽  
pp. 1883-1886 ◽  
Author(s):  
Ruth Halaban
Keyword(s):  
Circadian Rhythm ◽  
Constant Light ◽  
Leaf Movement ◽  
Light Conditions ◽  
Short Day ◽  
Coleus Blumei

O-158 The effect of circadian rhythm disruption due to constant light on ovarian and oocyte aging through possible relationship between PER2 and mTOR signaling pathway

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
G Bora ◽  
T Onel ◽  
E Yildirim ◽  
A Yaba
Keyword(s):  
Circadian Rhythm ◽  
Food Intake ◽  
Signaling Pathway ◽  
Constant Light ◽  
Light Conditions ◽  
Mtor Signaling Pathway ◽  
Protein Levels ◽  
Ovarian Morphology ◽  
Oocyte Aging ◽  
P70 S6k

Abstract Study question Does circadian rhythm disruption by constant light affect the ovarian morphology and function, and cause ovarian and oocyte aging through possible relationship between PER2 and mTOR? Summary answer We demonstrated that circadian rhythm disruption by light may cause ovarian and oocyte aging. What is known already Circadian rhythm regulates multiple physiological processes and PER2 is one of the core circadian rhythm components. Changes in light conditions may cause circadian rhythm disruptions. Light exposure at night may cause attenuation in PER2 mRNA and protein levels. Circadian rhythm disruptions are thought to be associated with reproductive diseases. mTOR signaling pathway functions in folliculogenesis and oocyte maturation in ovary. Also, it is associated with ovarian and oocyte aging. Study design, size, duration A total of 32 female Balb/c mice which enter estrous cycle were used in the study. Mice were randomly assigned to one of two groups as 12:12h L:D and 12:12h L:L. During the experiment, 12:12h L:D (control group) was housed in a 12:12h light:dark cycle and 12:12h L:L (experiment group) was housed in a constant light conditions 12:12h light:light for 1 week. Participants/materials, setting, methods We housed 12:12h L:D group in standard lightening conditions and 12:12h L:L group in constant light for one week. We performed food intake and body weight change analysis. We evaluated ovarian morphology, follicle counting analysis. We evaluated ZP3 and nitrotyrosine (NTY) expression for oocyte aging markers. We performed western blot for PER2, mTOR, p-mTOR, p70 S6K, p-p70 S6K, and Caspase-3 protein levels. Main results and the role of chance We demonstrated that circadian rhythm disruption caused alteration in their food intake and decrease in primordial follicle numbers and increase in atretic follicles (p < 0.05). It caused increase in oxidative stress and decrease in ZP3 expression in oocytes (p < 0.05). We showed decreased protein levels of PER2, mTOR, p-mTOR and p70 S6K (p < 0.05).  Limitations, reasons for caution The explanation of molecular mechanism underlying the relationship between circadian rhythm disruptions by light and ovarian function may lead the usage of circadian rhythm-based or light-based therapies currently using to treat some diseases on female reproductive system related diseases. Wider implications of the findings We conclude that constant light may reduce follicle reserve, cause follicles to go rapidly atresia and disrupt the oocyte quality, thus it may be a risk factor for female reproductive diseases such as premature ovarian insufficiency and early menopause.  Trial registration number not applicable

Phase Shifting Effect of Caffeine in the Circadian Rhythm of Phaseolus coccineus L

1975 ◽  
Vol 30 (11-12) ◽  
pp. 855-856 ◽  
Author(s):  
W. Mayer ◽  
I. Scherer
Keyword(s):  
Circadian Rhythm ◽  
Phaseolus Coccineus ◽  
Phase Shifting ◽  
Leaf Movement ◽  
Circadian Leaf Movement

Abstract Caffeine, Circadian Rhythm, Sleep and Wakefulness, Phaseolus coccineus L. 4-hour caffeine pulses (10 mᴍ) offered via the trans­ piration stream advances or delays the phase of the circadian leaf movement rhythm of Phaseolus coccineus as a function of the phase of application. It is hypothesized that the caffeine effect upon sleep and wakefulness in man is partly due to this phase-shifting effect.

Leaf Movement Rhythm In Arabidopsis Thaliana

1992 ◽  
Vol 47 (11-12) ◽  
pp. 925-928 ◽  
Author(s):  
Wolfgang Engelmann ◽  
Karl Simon ◽  
Chen Jyh Phen
Keyword(s):  
Arabidopsis Thaliana ◽  
Circadian Rhythm ◽  
Computer System ◽  
Leaf Movement ◽  
Leaf Movements ◽  
Weak Light

A circadian rhythm of leaf movements of Arabidopsis thaliana and its recording in continuous weak light with a video-computer system is described

scholarly journals Fluctuating light experiments and semi-automated plant phenotyping enabled by self-built growth racks and simple upgrades to the IMAGING-PAM

Plant Methods ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Dominik Schneider ◽  
Laura S. Lopez ◽  
Meng Li ◽  
Joseph D. Crawford ◽  
Helmut Kirchhoff ◽  
...  
Keyword(s):  
Data Analysis ◽  
Low Cost ◽  
Growth Conditions ◽  
Research Field ◽  
Constant Light ◽  
Plant Phenotyping ◽  
Natural Light ◽  
Light Conditions ◽  
Fluctuating Light ◽  
Science Labs

Abstract Background Over the last years, several plant science labs have started to employ fluctuating growth light conditions to simulate natural light regimes more closely. Many plant mutants reveal quantifiable effects under fluctuating light despite being indistinguishable from wild-type plants under standard constant light. Moreover, many subtle plant phenotypes become intensified and thus can be studied in more detail. This observation has caused a paradigm shift within the photosynthesis research community and an increasing number of scientists are interested in using fluctuating light growth conditions. However, high installation costs for commercial controllable LED setups as well as costly phenotyping equipment can make it hard for small academic groups to compete in this emerging field. Results We show a simple do-it-yourself approach to enable fluctuating light growth experiments. Our results using previously published fluctuating light sensitive mutants, stn7 and pgr5, confirm that our low-cost setup yields similar results as top-prized commercial growth regimes. Moreover, we show how we increased the throughput of our Walz IMAGING-PAM, also found in many other departments around the world. We have designed a Python and R-based open source toolkit that allows for semi-automated sample segmentation and data analysis thereby reducing the processing bottleneck of large experimental datasets. We provide detailed instructions on how to build and functionally test each setup. Conclusions With material costs well below USD$1000, it is possible to setup a fluctuating light rack including a constant light control shelf for comparison. This allows more scientists to perform experiments closer to natural light conditions and contribute to an emerging research field. A small addition to the IMAGING-PAM hardware not only increases sample throughput but also enables larger-scale plant phenotyping with automated data analysis.

The synchronized cell cycle of Neochloris oleoabundans and its influence on biomass composition under constant light conditions

2013 ◽  
Vol 2 (4) ◽  
pp. 313-320 ◽  
Author(s):  
Lenneke de Winter ◽  
Anne J. Klok ◽  
Maria Cuaresma Franco ◽  
Maria J. Barbosa ◽  
René H. Wijffels
Keyword(s):  
Cell Cycle ◽  
Biomass Composition ◽  
Constant Light ◽  
Neochloris Oleoabundans ◽  
Light Conditions
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