Arabidopsis thaliana root growth kinetics and lunisolar tidal acceleration

Abstract

Summary• All living organisms on Earth are continually exposed to diurnal variations in the gravitational tidal force due to the Sun and Moon.• Elongation of primary roots of Arabidopsis thaliana seedlings maintained at a constant temperature was monitored for periods of up to 14 d using high temporal-and spatialresolution video imaging. The time-course of the half-hourly elongation rates exhibited an oscillation which was maintained when the roots were placed in the free-running condition of continuous illumination.• Correlation between the root growth kinetics collected from seedlings initially raised under several light protocols but whose roots were subsequently in the free-running condition and the lunisolar tidal profiles enabled us to identify that the latter is the probable exogenous determinant of the rhythmic variation in root elongation rate. Similar observations and correlations using roots of Arabidopsis starch mutants suggest a central function of starch metabolism in the response to the lunisolar tide. The periodicity of the lunisolar tidal signal and the concomitant adjustments in root growth rate indicate that an exogenous timer exists for the modulation of root growth and development.• We propose that, in addition to the sensitivity to Earthly 1G gravity, which is inherent to all animals and plants, there is another type of responsiveness which is attuned to the natural diurnal variations of the lunisolar tidal force.

An improved agar-plate method for studying root growth and response of Arabidopsis thaliana

“…Illuminated roots display the light-escape tropism via faster root growth89. Secondly, elongation rate of Arabidopsis primary root in darkness is higher than that in light under long photoperiods (16 h:8 h or 12 h:12 h, light : dark)17. Thirdly, in the presence of exogenous sucrose, Arabidopsis root can grow both in light and darkness.…”

The botanical multiverse of Peter Barlow

“…More recently, Peter's interests turned towards the moon and the influence that this satellite may have on biological phenomena on Earth [99]. That conference presentation was followed up by many papers investigating the influence of the moon on such plant phenomena as leaf movements [99][100][101], stem elongation [102], fluctuations in diameters of tree stems [103], root growth [104][105][106], emissions of biophotons by seedlings [107][108][109][110], and chlorophyll fluorescence [111]. Not constrained by gravity, Peter was also developing ideas about extraterrestrial influences and plant bioelectricity [112].…”

The effect of lunisolar tidal acceleration on stem elongation growth, nutations and leaf movements in peppermint (Mentha × piperita L.)

“…Similarly, physiological processes in plants, such as those expressed in the kinetics of root elongation in Arabidopsis (Fisahn et al . ), light emission from germinating wheat seedlings (Gallep et al . ) and chlorophyll fluorescence (Fisahn et al .…”