Endogenous rhythmicity and energy transduction. II. Phytochrome action and the conditioning of rhythmicity of adenylate kinase, NAD- and NADP-linked glyceraldehyde-3-phosphate dehydrogenase in Chenopodium rubrum by temperature and light intensity cycles during germination

1973 ◽  
Vol 51 (8) ◽  
pp. 1521-1528 ◽  
Author(s):  
Silvia Frosch ◽  
Edgar Wagner
Keyword(s):  
Light Intensity ◽  
Adenylate Kinase ◽  
Dark Period ◽  
Energy Transduction ◽  
Endogenous Rhythm ◽  
Chenopodium Rubrum ◽  
Germination Period ◽  
Endogenous Rhythmicity ◽  
Free Running

Endogenous rhythmicity in NADP- and NAD-linked glyceraldehyde-3-phosphate dehydrogenase (NADP- and NAD-GPD) as well as in adenylate kinase (AK) activity is initiated or synchronized during cyclic germination conditions of light and temperature, and is free-running in a dark period interrupting continuous light.There is phytochrome control of the amplitude in NADP-GPD and AK oscillations during the first hours of darkness if the beginning of the dark period is in phase with the beginning of the germination period. The endogenous rhythm acts like an "on-off" switch for potential phytochrome action. The results are discussed in relation to daily photoperiodic cycles.

Betacyanin accumulation, chlorophyll content, and flower initiation in Chenopodium rubrum as related to endogenous rhythmicity and phytochrome action

1970 ◽  
Vol 48 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Edgar Wagner ◽  
Bruce G. Cumming
Keyword(s):  
Gibberellic Acid ◽  
Chlorophyll Content ◽  
Dark Period ◽  
Continuous Light ◽  
High Energy ◽  
Hypocotyl Elongation ◽  
Chenopodium Rubrum ◽  
Physiological Status ◽  
Flower Initiation ◽  
Endogenous Rhythmicity

In Chenopodium rubrum seedlings (ecotypes 50°10′ N and 49°58′ N) betacyanin synthesis is light dependent (completely dark-grown seedlings contain no betacyanin) and is under phytochrome control via both the low energy and the high-energy (HER) reactions of photomorphogenesis. In continuous light, accumulation of betacyanin is linear with time. However, when a single dark period interrupts continuous light, the amount of both betacyanin and chlorophyll synthesized during a given period of time after the dark interruption shows a rhythm reflecting differences in the rate of, and (or) the capacity for, pigment accumulation that are dependent on the duration of the dark period. The rhythm in chlorophyll content was higher in frequency than circadian, with a period of about 15 h, while rhythmicity in the rate of synthesis of betacyanin was circadian. These results suggest that there is endogenous rhythmicity in the metabolic state of the system in darkness. The imposition of light after darkness apparently stabilizes the specific physiological status attained at that respective time of darkness and thus determines the metabolic activity of the seedlings.When glucose was supplied throughout darkness interrupting continuous light, the phasing of the rhythm of betacyanin synthesis was positively correlated with the rhythm of flower initiation, but this was not so when phenylalanine was supplied during darkness. In contrast, when glucose was supplied for a varied length of time in continuous light, there was rhythmicity in the rate of betacyanin accumulation, with a periodicity of about 15 h, that was dependent on the duration of the glucose application.When seedlings were supplied with 10−6 M gibberellic acid during darkness there was a rhythm in the amount of hypocotyl elongation that depended on the length of a single dark period interrupting continuous light. Other evidence has suggested that there is a rhythm in the stability of the cellular membranes; this rhythm was assayed (non-physiologically) by the time of onset of betacyanin leakage from seedlings into an extraction medium and was apparent only after application of 10−10 M gibberellic acid. The rhythms in hypocotyl elongation and in membrane stability that were revealed after the application of gibberellic acid suggest that there may be a rhythm in the rate of differentiation and (or) development of the system.It is postulated that endogenous rhythmicity is due to the spatial separation of energy production and use in different cell particulates, with phytochrome acting as a membrane operator.

Endogenous rhythmicity and energy transduction. III. Time course of phytochrome action in adenylate kinase, NAD- and NADP-linked glyceraldehyde-3-phosphate dehydrogenase in Chenopodium rubrum

1973 ◽  
Vol 51 (8) ◽  
pp. 1529-1535 ◽  
Author(s):  
Silvia Frosch ◽  
Edgar Wagner
Keyword(s):  
Enzyme Activity ◽  
Adenylate Kinase ◽  
Time Course ◽  
Functional Relationship ◽  
Relative Concentration ◽  
Red Light ◽  
Endogenous Rhythm ◽  
Activated State ◽  
Endogenous Rhythmicity ◽  
Time Courses

Evidence is presented that phytochrome triggers and maintains the increase in adenylate kinase (AK) as well as NAD- and NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (NAD- and NADP-GPD) activity. After cyclic germination conditions, the time courses of all three enzymes display an endogenous rhythmic increase of their activities in constant far-red light. After germination in constant conditions, NAD- and NADP-GPD activities displayed no rhythm, while AK activity increased rhythmically. Such readiness of AK activity to oscillate was taken as indication of a close functional relationship between the control mechanism(s) of the endogenous rhythm and AK activities. The time courses in NADP-GPD activity demonstrated that phytochrome acted as an on-off switch for the increase in enzyme activity and also controlled enzyme activity depending on the relative concentration of active phytochrome. There is evidence for a function of phytochrome in the "ground state" as well as in an "activated state."It is suggested that phytochrome could be coupled to endogenous rhythmicity by modulating the redox potential of the cell, while phytochrome action itself would be timed by the endogenous rhythm.

Conditioning circadian rhythmic control of betacyanin content in Chenopodium rubrum by temperature and light intensity cycles during germination

1971 ◽  
Vol 49 (11) ◽  
pp. 1981-1985 ◽  
Author(s):  
Edgar Wagner ◽  
Silvia Frosch
Keyword(s):  
Circadian Rhythm ◽  
Light Intensity ◽  
Metabolic Activity ◽  
Time Course ◽  
Chenopodium Rubrum ◽  
Light Conditions ◽  
Dark Light ◽  
Cyclic Temperature ◽  
Free Running ◽  
Specific Phase

Evidence is presented that a circadian rhythm in betacyanin accumulation in Chenopodium rubrum seedlings (ecotype 50°10′ N, 105°35′ W, selection 184) was initiated or synchronized by the cyclic temperature and light conditions that were imposed during germination. This rhythm was probably free-running in the constant light conditions that preceded the imposition of darkness. Rhythmic fluctuations in the time course of betacyanin content during darkness, which are probably due to betacyanin turnover, showed correlations with the alternating germination conditions, thus indicating that the rhythm is not initiated or rephased by the transition from light of 600 or 3000 ft-c to darkness. Light following darkness increased the respective level of betacyanin accumulation but did not alter the phasing of the rhythm as compared with darkness. The metabolic activity of the seedlings in the light, following darkness, depends on the specific phase of the endogenous rhythm at the time of the dark: light transition.

RHYTHMIC FLOWERING RESPONSES AND PHYTOCHROME CHANGES IN A SELECTION OF CHENOPODIUM RUBRUM

1965 ◽  
Vol 43 (7) ◽  
pp. 825-853 ◽  
Author(s):  
Bruce G. Cumming ◽  
Sterling B. Hendricks ◽  
H. A. Borthwick
Keyword(s):  
Dark Period ◽  
Continuous Light ◽  
Endogenous Rhythm ◽  
Chenopodium Rubrum ◽  
Flowering Response ◽  
Initial Substrate ◽  
Endogenous Circadian Rhythm ◽  
Light Darkness ◽  
Rhythmic Change

Flowering of Chenopodium rubrum L., selection 374, was examined with respect to an endogenous circadian rhythm, the state of phytochrome, and the result of changing the form of phytochrome during a single dark period of 2 to 96 hours interrupting continuous light. Darkness was imposed either 4 or 5 days after seeds were placed on moist filter paper in Petri dishes.The following working hypothesis, which is partly retrospective, is projected to explain the main features of the experimental results. Flowering is controlled by a product of the enzymatic action of the far-red absorbing form of phytochrome (Pfr) on a single but unknown substrate. In acting, Pfr finally reverts to the inactive red-absorbing form of phytochrome (Pr) or is changed from the Pfr form in some other way. The available substrate, if not utilized by Pfr action, is soon depleted by other reactions. The substrate for Pfr action is low during the skotophile but high during the photophile phases. The significant time for phasing is the beginning of darkness. The initial substrate supply appears to be derived from the preceding light period but some time in the region of the 9th to 12th hour of darkness a significant rhythmic change of substrate starts up. The dependence of flowering on the time that darkness is interrupted by light is directly related to a rhythmic change in the optimum Pfr level required for the processes leading to flowering.The role of the endogenous rhythm in flowering under natural conditions is questioned. Similarities that are shown in the control of flowering, whether the display is governed by an endogenous rhythm or by a daily photoperiodic cycle, indicate that phytochrome acts as a "pacemaker". It is suggested that the distinct ecotypic populations of C. rubrum that differ in flowering response have dissimilar levels and rates of supply of substrate for phytochrome action. In C. rubrum-374, complete reversion or loss of Pfr does not occur during a long dark period of 72 hours at 20 °C, but Pfr does decrease to low levels.A hydrodynamic system is discussed as an analogy to rhythmic flowering response.

Photic resetting of intrinsic rhythmicity of the rat suprachiasmatic nucleus under various photoperiods

1998 ◽  
Vol 274 (3) ◽  
pp. R857-R863 ◽  
Author(s):  
Alena Sumová ◽  
Helena Illnerová
Keyword(s):  
Suprachiasmatic Nucleus ◽  
Dark Period ◽  
Light Exposure ◽  
Light Stimulus ◽  
Phase Shifts ◽  
Late Night ◽  
Fos Protein ◽  
Endogenous Rhythmicity ◽  
Protein Immunoreactivity ◽  
First Time

To date, photic entrainment of the mammalian circadian system has been studied by following phase shifts of overt rhythms in the periphery governed by a circadian pacemaker located in the suprachiasmatic nucleus (SCN). The present study follows for the first time photic resetting of intrinsic rhythmicity of the SCN itself. Rats maintained under either a shorter photoperiod, with 12 h of light and 12 h of darkness per day, or under a long, 18:6-h light-dark photoperiod were exposed to a light stimulus during the dark period and then released into darkness, and the next day the SCN rhythm in the light-stimulated c-Fos protein immunoreactivity was followed as a marker of the SCN endogenous rhythmicity. After a light stimulus in the early night, the evening rise in the photic elevation of Fos protein photoinduction as well as the morning decline were phase delayed within one cycle. After a light stimulus in the late night, only the morning decline in the photic elevation of Fos was phase advanced the next night, not the evening rise; consequently, the interval enabling high photic elevation of Fos was reduced. After a light stimulus was administered around the middle of the night, the next night the evening rise in the light-stimulated Fos was eventually phase delayed, the morning decline was phase advanced, and the rhythm amplitude was reduced significantly; under 18:6-h light-dark, a mere 5-min light exposure exhibited such effects. The data indicate that resetting of the SCN rhythmicity in the light-elevated c-Fos 1 day after a resetting stimulus administration, i.e., during transient cycles, may proceed via nonparallel phase shifts of the evening rise and of the morning decline of the light-stimulated Fos, and via amplitude lowering and suggest a complex circadian pacemaking system in the rat SCN.

Diel Periodicity of Chlorophyll a Concentration in Oregon Coastal Waters

1972 ◽  
Vol 29 (9) ◽  
pp. 1253-1259 ◽  
Author(s):  
Walter A. Glooschenko ◽  
Herbert Curl Jr. ◽  
Lawrence F. Small
Keyword(s):  
Light Intensity ◽  
Chlorophyll A ◽  
Coastal Waters ◽  
Dark Period ◽  
Skeletonema Costatum ◽  
Time Of Day ◽  
Light Period ◽  
Diel Periodicity ◽  
Low Light ◽  
Chlorophyll Precursor

Concentrations of chlorophyll a in phytoplankton exhibited a diel periodicity in Oregon coastal waters. Maximum surface concentrations often occurred around midnight and highest 25-m concentrations early in the evening (or even in late afternoon). Concentrations at intermediate depths fell in between and in a predictable progression with depth and time of day. Minimum chlorophyll a values occurred in the afternoon. No definite periodicity was established at 50 m.Laboratory studies with Skeletonema costatum demonstrated that the diel cycle of chlorophyll a per cell was related to the light intensity and duration to which cells were exposed. Highest concentrations of this pigment occurred early in the dark period and lowest concentrations in the light period when cells were grown under photoperiods of 9, 12, and 15 hr at a light intensity of approximately 1200 ft-c. Pigment bleaching probably was responsible for the low concentrations during the light period. The decline of chlorophyll a from the maximum early in the dark period began after the cells possibly became deficient in some chlorophyll precursor or energy-yielding substrate. Addition of an external carbon source during the dark period prolonged the high chlorophyll a concentrations in the dark before the decline began. Under low light (400 ft-c) chlorophyll a synthesis occurred only in the light. This phenomenon was most likely due to an insufficient amount of energy-yielding substrate or precursor synthesized during the low-light period, and the lack of bleaching in the light period at this lower intensity. The laboratory results were consistent with interpretations of the field data. A correction for diel pigment periodicity is recommended for models estimating photosynthesis from chlorophyll and light data and for oceanographic surveys during which sampling of chlorophyll a is carried out throughout the 24-hr day.

scholarly journals Effect of Incubation Temperature, Light Intensity and Salinity on Growth, Lipid Content and Composition of Two Egyptian Race a of Botryococcus Braunii

2019 ◽  
pp. 1-9
Author(s):  
Mohammad I Abdel-Hamid ◽  
◽  
Yehia A Azab ◽  
Eman I Abdel-Aal ◽  
◽  
...  
Keyword(s):  
Light Intensity ◽  
Lipid Content ◽  
Incubation Temperature ◽  
Dark Period ◽  
Dry Weight ◽  
Botryococcus Braunii ◽  
Nacl Salinity ◽  
Potential Source ◽  
Chain Compounds ◽  
Very High

Effects of the incubation temperature, light intensity and NaCl salinity on growth in addition to lipid content and composition of two isolates of Botryococcus braunii, (JN580448.1 and JN580451.1) were investigated. The light to dark period was 16h: 8h. Cultures were incubated for 7 weeks and harvested with GF/C filters for dry weight determination. Lipids were extracted by n-hexane and analyzed by GC/MS. Compared to control cultures, the temperature of 30oC induced significant (P ≤ 0.05) increase in biomass by 14.89% and 29.89% and lipids by 16.15% and 20.29% for isolates EG-Bb01 and EG-Bb04, respectively. The light intensity 48.6 μ mol photons m-2s-1 induced very high significant (P ≤ 0.001) increase in biomass (88.71% and 100.7%) and lipids (118.63% and 94.61%) of EG-Bb01 and EGBb04, respectively. Similarly, 17 mM NaCl salinity induced high significant (P ≤ 0.01) increase in biomass (23.82% and 17.71%) and lipids (32.92% and 24.51%) of EG-Bb01 and EG-Bb04, respectively. Considerable numbers of short C6-C15 chain compounds were detected in biomass of cultures grown under light intensity of 48.6 μ mol photons m-2s-1 and in cultures supplemented with 17mM NaCl. These results may indicate that the Egyptian isolates of Botryococcus are potential source of hydrocarbon biofuel.

Effects of micro-environmental factors on the photoautotrophic growth of Hibiscus sagittifolius Kurz cultured in vitro

2018 ◽  
Vol 39 (4) ◽  
pp. 496-506 ◽  
Author(s):  
Nguyen Thuy Phuong Duyen ◽  
Tran Thi Van ◽  
Nguyen Thu Le Minh ◽  
Nguyen Thi Quynh
Keyword(s):  
Environmental Factors ◽  
Light Intensity ◽  
Leaf Area ◽  
Dark Period ◽  
Dry Weight ◽  
Fresh Weight ◽  
Photoautotrophic Growth ◽  
Temperature Regimes ◽  
Folk Remedy

The arrow leaf abelmoschus rhizome (Hibiscus sagittifolius Kurz), or Sam Bo Chinhin Vietnamese, is a perennial suffrutex herb from which the tuber root is used as a medicine in folk remedy. This species is widely distributed and can be found on many terrains across South East Asia. With an aim to create a large number of uniform and high-quality H. sagittifolius transplants in vitro, effects of some environmental factors such as photoperiod and temperature on the photoautotrophic growth of H. sagittifoliusin vitro plants were investigated. In vitro single nodal cuttings, each with an unfolded leaf, were cultured photoautotrophically (without sucrose and vitamins) on mineral SH medium, under light intensity of 150 µmol m-2 s-1, temperature of 24oC ± 2oC, relative humidity (RH) of 55% ± 5% and three different photoperiods (8, 12 or 16 h d-1) in the first experiment. Commercial polypropylene bags (V = 1,000 ml), attached with two filter-paper membranes, were used as culture vessels. After 42 days of culture, H. sagittifolius plants under the photoperiod of 16 h d-1 had the greatestincreased fresh weight (502.3 mg/plt), increased dry weight (39.5 mg/plt) and leaf area (17.0 cm2) than those put under 8 hd-1or 12 h d-1. In addition, H. sagittifolius plants also showed statistical differences in growth when photoautotrophically cultured in different air temperature regimes, including 28/25oC (photo-/dark period), 25/25oC and 20/25oC. Increased fresh weight (775 mg/plt), increased dry weight (62 mg/plt) and leaf area (22.7 cm2) of in vitro H. sagittifolius plants were the greatest when temperature was maintained at 28 oC during photoperiod. On the contrary, the photoperiod temperature of 20oC resulted in the shortest shoot length and root length of H. sagittifoliusplants. In conclusion, this study proved that H. sagittifolius plants had the best growth when cultured on SH medium, without sucrose and vitamins supplementation, under light intensity of 150 µmol m-2 s-1, RH 55% ± 5%, photoperiod of 16 h d-1, temperature regime of 28/25oC(photo-/dark period). Citation: Nguyen Thuy Phuong Duyen, Tran Thi Van, Nguyen Le Thu Minh, Nguyen Thi Quynh, 2017. Effects of micro-environmental factors on the photoautotrophic growth of Hibiscus sagittifolius Kurz cultured in vitro. Tap chi Sinh hoc, 39(4): 496-506. DOI: 10.15625/0866-7160/v39n4.11030. *Corresponding author: [email protected] 7 September 2017, accepted 15 December 2017

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