Ultraweak, spontaneous photon emission in seedlings: toxicological and chronobiological applications

Abstract

The detection of ultraweak light emission in seedlings has been explored in toxicological and chronobiological studies. The main studies in this area are reviewed briefly, including a report on applied tests held in the last 7 years at LaFA--UNICAMP (Brazil). In general, results indicate that a linear relation for total light emission versus germination performance is found if only strong stress situations are considered, when external factors depress a seedling's development, even when considering a sequential series of tests. Light emitted by a single seedling was detected in a compact apparatus, and data are presented here for the first time showing pronounced circadian cycles are evident, with similar time and frequency profiles as those of the local gravimetric tide.

Light based cellular interactions: hypotheses and perspectives

“…The exact biochemical mechanisms were explained recently by Pospíšil [26]. Depending on what type of reactions are the sources and what kind of components are inside the cells, we will have different types of wavelength ranges and the intensities [15,41,42] of UPE. Also we should not omit that ROS are themselves part of multiple signaling pathways [43] and therefore already contain an interesting amount of information.…”

Time-resolved ultra-weak photon emission as germination performance indicator in single seedlings

“…Long term, day-length recordings of spontaneous UPE during the development of seedlings were first presented by Yan in 2006 [13] . Shortly after, UPEs were shown to be analytically useful by the Laboratory of Applied Photonics in Campinas, Brazil [14 , 15] , as light emissions constitute reliable indicators of seed germination and development in chronic toxicological testing conditions, with more developed seedlings presenting more photon counts. Under acute stress, when a chemical stressor is applied after the first days of germination, the response is the opposite, with the more damaged, less developed sprouts presenting higher photon-counts, just after the stress, than the control samples, and the burst lasting for few hours (6–12 h) [16] .…”

Short-time fractal analysis of biological autoluminescence

“…This light phenomenon differs from a rather bright bioluminescence which is dependent a specific enzymatic complexes which are present only in very specific species such as fireflies and selected jellyfish. What differentiates the general biological autoluminescence from ordinary bioluminescence is, apart the weaker intensity, its ubiquity across biological species ranging from microorganisms [2][3][4][5] through tissue cultures [6][7][8], plants [9][10][11][12][13] up to animals [14] including human [15][16][17]. There are also various synonyma used in the literature describing this light phenomenon such as ultra-weak photon emission [18], ultra-weak bioluminescence [19], endogenous biological chemiluminescence [20], biophotons [21][22][23], etc.…”