Daily pH Flux in the Water Media of the Chrysanthemum Root Zone Suggests Evidence of a Circadian Rhythm
Gorman RT1*, Tioran ME1, Sykes AL1, Leidy RB1, Gordon AM1, Harris EP1
1 Research Triangle Park Laboratories, Inc., 7201 ACC Blvd., Suite 104, Raleigh NC 27617
* Correspondence: Phone: (919) 510-0228; Fax: (919) 510-0141; Email: rtg@rtp-labs.com
Key Words: pH flux, circadian rhythm, aquaculture, splitting water, biological clock, plants
Received 4 October 2010; Revised 2 March 2011; Accepted 23 April 2011; Published 22 June 2011; Available Online 1 July 2011
Summary
Cycles in nature have long been observed and recorded, yet only a portion of the biological clock has been described and the origin of the cyclical process remains obscure. The potential causes of circadian rhythms are many—among which light, chemical, and temperature variations are the most likely. We examined the relationship of temperature, nitrogen compounds in water, and pH under both light and dark conditions to determine if a pH oscillation exists. The pH flux observed in the water media of our studies of Chrysanthemum plants indicates a daily circadian rhythm that is reproducible, predictable, and unaffected by the presence or absence of light or nutrients in the media. Moreover, this circadian rhythm was found to occur in one other species. Parity of temperature revealed the pH flux, which has a sine-wave function with observed amplitude of six-plus pH units from pH <3 to pH >9. The trough of pH <3 was attributed to acid exudates in the root environment. The peak of pH >9 was considered to be the result of hydroxyl groups produced by the splitting of water. Peak values of pH >9 observed in this study suggest that a single activity occurs independent of light or dark. If water splitting is the source of this high pH, then proton separation resulting in the formation of hydroxyl groups may be independent of light energy. Water splitting may thus be a common occurrence, although the source of this activity remains unknown. This circadian rhythm—as evidenced by a pH flux—potentially represents a form of biological clock in which the pH flux is an energy-transfer system, which could in turn contribute to some biological activity. The ramifications are that water splitting appears to be independent of light-energy input and a pH change within the cell could have a major influence on metabolic activity.