Increase in nitrate uptake by soybean plants during interruption of the dark period with low intensity light

1991 ◽  
Vol 81 (2) ◽  
pp. 183-189
Author(s):  
C. David Raper Jr ◽  
J. Kevin Vessey ◽  
Leslie T. Henry
Keyword(s):  
Nitrate Uptake ◽  
Dark Period ◽  
Low Intensity ◽  
Soybean Plants

Variability in photoperiod and the inhibition of flowering in a high latitude population of Saxifraga rivularis

1981 ◽  
Vol 59 (3) ◽  
pp. 388-391 ◽  
Author(s):  
J. A. Teeri ◽  
S. J. Tonsor
Keyword(s):  
High Latitude ◽  
High Intensity ◽  
Dark Period ◽  
Controlled Environment ◽  
Photoperiodic Control ◽  
Incandescent Light ◽  
Devon Island ◽  
Low Intensity ◽  
Long Day ◽  
Long Day Plants

A population of Saxifraga rivularis L. collected at Truelove Lowland, Devon Island, N.W.T., Canada (75°41′ N) exhibits a photoperiodic control of flowering in controlled environment chambers. The plants respond in a manner typical of long-day plants with flowering inhibited by either a 6-h daily dark period, or by a 6-h daily low intensity irradiance regime of incandescent light. The inhibition of flowering by 6 h day−1 of incandescent light does not occur if the incandescent light is given in twelve 0.5-h doses, each followed by 1 h of red-rich high intensity irradiance.

scholarly journals The involvement of gibberellins in phytochrome-controlled flowering of Pharbitis nil

2014 ◽  
Vol 71 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Halina Kulikowska-Gulewska ◽  
Jan Kopcewicz
Keyword(s):  
Seedling Growth ◽  
White Light ◽  
Dark Period ◽  
Light Flash ◽  
Total Content ◽  
Light Period ◽  
Pharbitis Nil ◽  
Low Intensity ◽  
Controlled Flowering ◽  
Growth Of Seedlings

The seedlings of <em>Pharbitis nil</em>, a sesitive short-day plant (SDP), were cultivated under special photoperiodic conditions: 72-h-long darkness, 24-h-long white light with low intensity, 24-h-long inductive night. During 24-h-long inductive darkness the total content of gibberellins in cotyledons underwent fluctuations with a maximum at 0 h and 8 h, and a decrease at the end of the dark period. FR light applied at the end of the 24-h-long white-light period inhibited flowering. R light flash and partially exogenous GA3 added on cotyledons could reverse the effect of FR. The seedling growth was not affected by FR and R light irradiation, but was promoted by exogenous GA3 application. The obtained results suggest that gibberellins are involved in photoperiodic control of SDP <em>P. nil</em> flowering. This involvement has nothing in common with participation of gibberellins in the control of the elongation growth of seedlings.

Die Tagesperiodik der Photosynthese bei Acetabularia und ihre Abhängigkeit von Kernaktivität, RNS- und Protein-Synthese

1963 ◽  
Vol 18 (12) ◽  
pp. 1085-1090 ◽  
Author(s):  
Gerhard Richter
Keyword(s):  
Diurnal Rhythm ◽  
Rna Synthesis ◽  
Marine Alga ◽  
Photosynthetic Capacity ◽  
Dark Period ◽  
Biological Clock ◽  
Continuous Light ◽  
Low Intensity ◽  
Minimum Value ◽  
Clock Mechanism

Normal and enucleate cells of the unicellular marine alga Acetabularia crenulata showed a diurnal rhythm of photosynthesis when cultivated in a 12 hour cycle of light and dark; it is characterized by a maximum and a minimum value of photosynthetic capacity in the middle of the light and the dark period respectively. In cells which had been raised from zygotes in continuous light, and from which the nucleus had been removed by severing the basal rhizoid before exposure to the 12 hour light-dark schedule the typical photosynthetic rhythm occurred. Obviously the nucleus is not essential for the induction and the maintenance of the latter. In aged enucleate cells the rhythm of photosynthesis persisted even 33 days after removal of the nucleus; as synthesis of cellular RNA and proteins had ceased long before it is evident that DNA-dependent RNA synthesis is probably not involved in rhythmicity and in a biological clock mechanism. The observed diurnal rhythm of photosynthesis did not persist in continuous light of low intensity and in darkness.

Nitrate Uptake, Root and Shoot Growth, and Ion Balance of Soybean Plants during Acclimation to Root-Zone Acidity

1982 ◽  
Vol 143 (1) ◽  
pp. 5-14 ◽  
Author(s):  
Thomas W. Rufty, ◽  
C. David Raper, ◽  
William A. Jackson
Keyword(s):  
Nitrate Uptake ◽  
Shoot Growth ◽  
Root Zone ◽  
Ion Balance ◽  
Root And Shoot Growth ◽  
Soybean Plants

The low intensity light reaction of stomata: effects of red light on rhythmic stomatal behaviour in Xanthium pennsyIvanicum

1965 ◽  
Vol 162 (989) ◽  
pp. 567-574 ◽  
Keyword(s):  
Phase Shift ◽  
Dark Period ◽  
Red Light ◽  
Bright Light ◽  
High Energy ◽  
Light Reaction ◽  
Intensity Effect ◽  
Low Intensity ◽  
Young Leaves ◽  
Large Phase

It has been shown (Mansfield 1964 ) that exposure to very low intensity light, during what would otherwise be a 16 h dark period, causes a phase shift in a rhythm of ‘opening ability’ in Xanthium stomata so that they open less rapidly in bright light at the end of the period. This low intensity effect was found to be greatest at a wavelength of 703 nm , with old leaves, and this is now confirmed for young leaves, which are found to be even more sensitive. Interruptions of the 16 h dark period with short periods of relatively high intensity red light only produce a detectable phase shift if they are frequent. Phase shift is produced by 4 min of red light every half hour or 2 min every quarter hour and the latter treatment appears to be as effective as continuous irradiation with low intensity red light providing the same total energy. If the frequency or the intensity of the interruptions is reduced the resulting phase shift is much smaller. The large phase shift due to interruptions with red light every quarter hour is not reversed when each of these is immediately followed by a period of high energy far-red. The results suggest that this stomatal response to low intensity light operates through a pigment system different from that which drives the ordinary stomatal opening in light, for in the latter blue light is more effective than red. The possibility that phytochrome is involved in the low intensity reaction is considered.

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