Biological rhythms and physiological timing

Journal Article · Thu Jan 01 04:00:00 UTC 1976 · Annu. Rev. Plant Physiol.; (United States)

DOI:https://doi.org/10.1146/annurev.pp.27.060176.001111· OSTI ID:5340368

Hillman, W S

The topics considered, largely but not exclusively in higher plants, include questions on basic mechanism, the cell cycle, photosynthesis, intermediary metabolism, and photoperiodism. This chapter deals either with circadian rhythms, those in which the free-running period (under constant conditions) is of the order of 24 hr, or with others that may be related. As used here, the term rhythms simply denotes oscillations with properties not directly reflecting environmental fluctuations. This deliberately broad usage thus includes oscillations that persist under constant conditions for tens of cycles with those that damp after one or two, and those that are entrainable by external signals to a wide range of frequencies with those having a narrow resonance range. It also bypasses the question of whether even oscillations that, under apparently constant conditions, are self-sustained and maintain no invariable phase relationship to any known geophysical periodicity, might nevertheless still result from frequency-transformation by the organism of some such input. The many instances of properties between extreme persistence or precision on the one hand and extreme lability on the other make it at least reasonable, without compelling contrary evidence, to treat all circadian oscillations conforming to the broad definition as in some sense related.

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 5340368
• Journal Information: Annu. Rev. Plant Physiol.; (United States), Journal Name: Annu. Rev. Plant Physiol.; (United States) Vol. 27; ISSN ARPPA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
BIOMASS
CELL CONSTITUENTS
CELL CYCLE
CELL MEMBRANES
CHEMICAL REACTIONS
DAILY VARIATIONS
ENERGY SOURCES
GENETIC CONTROL
LIPIDS
MEMBRANES
METABOLISM
ORGANIC COMPOUNDS
PEST CONTROL
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHYSIOLOGY
PLANTS
RENEWABLE ENERGY SOURCES
SEASONAL VARIATIONS
SYNTHESIS
TEMPERATURE DEPENDENCE
VARIATIONS