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1) With Chlorella ellipsoidea cells, in the presence of 5x106M DSPD, or in its absence, the amounts of 14CO2 incorporatedin P-esters, serine-plus-glycine and alanine were larger underred light than under blue light, whereas blue light specificallyincreased 14CO2-incorporation in aspartate, glutamate, malateand fumarate (blue light effect). The amount of total 14C fixedunder blue or red light was greatly decreased by the additionof DSPD. When the concentration of DSPD was raised to 5x104M, practically no radioactivity was found, under blue or redlight, in aspartate, glutamate and fumarate. Radioactivity inalanine was greatly increased. Effects of higher concentrationof DSPD are explained as due to the inhibition of PEP carboxylaseactivity in Chlorella cells. 2) The percentage incorporation of 14C into aspartate and theother compounds mentioned above, under near infra-red illuminationwas significantly smaller than that under blue light and wasalmost equal to that under red light. These results along withthe effect of 5x106 M DSPD, exclude the possibility thatcyclic photophosphorylation is involved in the "blue light effect"mechanism. (Received December 12, 1969; ) 相似文献
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1) The wavelength effects on 14CO2-fixation by Chlorella cellswere studied, using monochromatic light of different light intensities. 2) Blue light (453 mµ) stimulated the incorporation of14C into aspartate, glutamate and malate. Red light (679 mµ),on the other hand, stimulated its incorporation into P-esters,free sugars and insoluble material. 3) The blue light effect was observed in the presence of CMUat concentrations completely suppressing ordinary photosyntheticCO2-fixation. 4) The blue light effect in the presence of CMU was inducedat very low intensities. At 453 mµ, 300 erg cm2sec1 was sufficient for complete saturation. 5) Time courses of 14C-incorporation into individual compoundswere investigated. Irrespective of the wavelength of the illuminatinglight, the first stable CO2-fixation product formed under weaklight (400500 erg cm2 sec1) was citrulline.At higher light intensities (4,0007,000 erg cm2sec1), PGA was the first stable CO2-fixation product.The incorporation of 14C into citrulline was not inhibited byCMU. 6) Experimental results indicate that both blue light-inducedincorporation of 14C into amino and organic acids and the incorporationof 14C into citrulline induced by low intensity light are operatedby a mechanism(s) independent of ordinary photosynthetic CO2-fixation.Possible effects of light regulating the carbon metabolism inalgal cells are discussed. (Received July 24, 1969; ) 相似文献
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Time Lapse Analysis of Root Elongation Rates of Rice and Sorghum During the Day and Night 总被引:4,自引:0,他引:4
This paper describes a technique to monitor the root elongationrate (RER) per hour for several days, and variation in RER duringthe day and night. Rice (Oryza sativaL.) and sorghum (SorghumbicolorMoench) were grown in root boxes placed inside a growthchamber set at 25 °C with a 12 h photoperiod. Seminal rootaxes were sandwiched between a transparent acrylic board andfilter paper placed on a loamy sand soil. The roots were photographedunder dim green light using a CCD camera connected to a timelapse video recorder. The environment of the root, includingtemperature, light, nutrient, water and air supply, was controlledprecisely and maintained constant. RER fluctuated hourly insorghum and to a greater extent in rice. Maximum RERs were 1.4to 4.4 times faster than minimum rates. RERs during the dayand night did not differ statistically when temperatures werethe same.Copyright 1998 Annals of Botany Company Oryza sativaL., periodicity, root elongation,Sorghum bicolorMoench, time lapse. 相似文献
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SHIGERU KIKUKAWA RYOU HASHIZUME MIHO HONDA YUKA INOUE TATSUYA MAEKAWA RISA SAKATA NANAKO TAKAHASHI KUNIAKI TANAKA YU UCHIDA 《Physiological Entomology》2013,38(3):253-259
In addition to photoperiod, thermoperiod (or thermocycle) might be an important Zeitgeber for entraining the circadian oscillator controlling adult eclosion rhythm in the Indian meal moth Plodia interpunctella Hübner (Lepidoptera: Pyralidae). This is confirmed by exposing larvae receiving diapause‐preventing treatments to various thermocycles with different means and amplitudes of temperature. The thermocycles investigated in the present study are TC 8 : 16 h, TC 12 : 12 h, TC 16 : 8 h and TC 20 : 4 h, where T and C represent thermophase (30 °C) and cryophase (20 °C), respectively. For all thermocycles, the peak of adult eclosion rhythm occurs at around the mid‐thermophase. This indicates that the larvae use both ‘temperature‐rise’ and ‘temperature‐fall’ signals to adjust the eclosion phase in each thermocycle. The absence (DD) or presence (LL) of light affects this time‐keeping system slightly under the given thermocycle. The rhythmic adult eclosion noted after exposure of larvae to 30 °C DD for 14 days is recorded in the thermocycles (TC 12 : 12 h, DD; mean temperature = 25 °C) with different amplitudes of 27.5/22.5 °C, 26.5/23.5 °C and 25.5/24.5 °C. The peak in adult eclosion advances in time as the amplitude of the temperature cycle decreases. In the temperature cycle of 25.5/24.5 °C, a peak occurs at the end of the cryophase, 2 h before the temperature‐rise. The adult eclosion rhythm is also observed under various thermocycles (TC 12 : 12 h, DD) consisting of different temperature levels (30 to 20 °C) with different amplitudes. It is found that the temporal position of the peak advances significantly when the amplitude of the thermocycle becomes lower. 相似文献
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YUKA OGASAWARA KIMITSUNE ISHIZAKI TAKAYUKI KOHCHI YUTAKA KODAMA 《Plant, cell & environment》2013,36(8):1520-1528
Organelles change their subcellular positions in response to various environmental conditions. Recently, we reported that cold treatments alter the intracellular position of chloroplasts and nuclei (cold positioning) in the fern Adiantum capillus‐veneris; chloroplasts and nuclei localized to the periclinal cell wall relocated to anticlinal cell wall after cold treatments. To further understand organelle positioning under cold conditions, we studied cold‐induced organelle relocation in the liverwort Marchantia polymorpha L. When sporelings and gemmmalings were treated under low temperature (5 °C), chloroplast cold positioning response was successfully induced both in the sporelings and the gemmmalings of M. polymorpha. Using a genetic transformation, nuclei, mitochondria or peroxisomes were visualized with a fluorescent protein, and the transgenic gemmmalings were incubated under the cold condition. Nuclei and peroxisomes, but not mitochondria, clearly relocated from the periclinal cell wall to the anticlinal cell wall after cold treatments. Our findings suggest that several organelles concurrently change their positions in the liverwort cell to cope with cold temperature. 相似文献
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Chlorella cells incubated in the dark longer than 12 hr showedpronounced blue light-induced 14CO2 fixation into aspartate,glutamate, malate and fumarate (blue light effect), whereasthose kept under continuous light showed only a slight bluelight effect, if any. 2) During dark incubation of Chlorellacells, phosphoenolpyruvate carboxylase activity and the capacityfor dark 14CO2 fixation decreased significantly, whereas ribulose-1,5-diphosphatecarboxylase activity and the capacity for photosynthetic 14CO2fixation (measured under illumination of white light at a highlight intensity) did not decrease. 3) In cells preincubatedin the dark, intracellular levels of phosphoenolpyruvate and3-phosphoglycerate determined during illumination with bluelight were practically equal to levels determined during illuminationwith red light. 4) The blue light effect was not observed incells incubated widi chloramphenicol, indicating that blue light-inducedprotein synthesis is involved in the mechanism of the effect. (Received April 9, 1971; ) 相似文献
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SHIGERU KIKUKAWA RYOU HASHIZUME MIHO HONDA YUKA INOUE TATSUYA MAEKAWA MINA MIYABAYASHI NATSUKO MORI RISA SAKATA NANAKO TAKAHASHI YUKI TAKIGAURA KUNIAKI TANAKA YU UCHIDA 《Physiological Entomology》2012,37(3):258-265
The rhythm of adult eclosion in the Indian meal moth Plodia interpunctella Hübner (Lepidoptera: Pyralidae) is investigated under various photoperiods and temperatures aiming to determine the nature of the temperature compensation and the free‐running period. Insects that are committed to a nondiapause larval development show diel rhythms of adult eclosion at 30, 25 and 20 °C. At 30 °C, the eclosion peak (i.e. the mean time of eclosion) occurs approximately 20 h after lights off under an LD 4 : 20 h photocycle, and at approximately 15 h under an LD 20 : 4 h photocycle. At 25 °C, the peak of eclosion occurs approximately 19 h after lights off under an LD 2 : 20 h photocycle and at approximately 16 h under an LD 20 : 4 h photocycle. At 20 °C, the eclosion peak is significantly advanced under long days of >12 h (i.e. approximately 20 h after lights off under an LD 4 : 20 h photocycle and approximately 9 h under an LD 20 : 4 h photocycle), indicating an effect of both lights‐off and lights‐on signals on the timing of the adult eclosion. To determine the involvement of a self‐sustained oscillator, the rhythm of adult eclosion is examined under darkness at different temperatures (30 to 21 °C). The mean free‐running periods are 22.4, 22.8, 22.0 and 22.5 h at 30, 24, 23 and 22 °C, respectively, indicating that the eclosion rhythm is temperature‐compensated. However, this rhythm does not free‐run under constant darkness at 21 °C. Because a clear diel rhythm is observed under 24‐h photocycles at 20 °C, the oscillator might be damped out within 24 h at the lower temperature. 相似文献
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