Circumnutation Tracker: novel software for investigation of circumnutation

Abstract

BackgroundAn endogenous, helical plant organ movement named circumnutation is ubiquitous in the plant kingdom. Plant shoots, stems, tendrils, leaves, and roots commonly circumnutate but their appearance is still poorly described. To support such investigations, novel software Circumnutation Tracker (CT) for spatial-temporal analysis of circumnutation has been developed.ResultsCT works on time-lapse video and collected circumnutation parameters: period, length, rate, shape, angle, and clockwise- and counterclockwise directions. The CT combines a filtering algorithm with a graph-based method to describe the parameters of circumnutation. The parameters of circumnutation of Helianthus annuus hypocotyls and the relationship between cotyledon arrangement and circumnutation geometry are presented here to demonstrate the CT options.ConclusionsWe have established that CT facilitates and accelerates analysis of circumnutation. In combination with the physiological, molecular, and genetic methods, this software may be a powerful tool also for investigations of gravitropism, biological clock, and membrane transport, i.e. processes involved in the mechanism of circumnutation.

Spontaneous action potentials and circumnutation in Helianthus annuus

“…The system was calibrated by a millimetre scale placed at the level of the pot. The time-lapse images were digitized using Circumnutation Tracker (Stolarz et al 2014). Experimental points (coordinates x, y of the stem apex on the horizontal plane) were determined at 1-or 5-min intervals.…”

“…Experimental points (coordinates x, y of the stem apex on the horizontal plane) were determined at 1-or 5-min intervals. The CN length (the distance that the organ apex covers during a single CN cycle) and the CN period (the time that the organ apex needs to trace a single circumnutation cycle) were calculated by Circumnutation Tracker software (Stolarz et al 2014). …”

The Kinematics of Plant Nutation Reveals a Simple Relation between Curvature and the Orientation of Differential Growth

“…As mentioned earlier, it is common to measure nutation by tracking the projection of the apical part of the organ in the horizontal plane [18,26]. In order to understand these measurements we first clearly state a sufficient and parsimonious set of hypotheses relating whole organ dynamics to the apical movement in the horizontal plane (which are otherwise generally implicitly assumed).…”

“…Furthermore, the sign of the effective dψg (t) dt is dominated by the faster oscillator. We now analyze an existing dataset of apical movements of 8 Arabidopsis thaliana plants published by Stolarz et al [18] (see Figure 8A, B, C and F for examples of measured apical patterns. Most of the observed patterns are elliptical.…”

“…A similar problem exists in the experimental measurement of nutation, where the full dynamics of plants in three-dimensional space and time are rarely taken into account. It is common, instead, to track the projection of the apical part of the organ in the plane orthogonal to the gravitational field ( defined here as the horizontal plane P a ) [18,26]. Such measurements carried out on different species and organs [1,26] exhibit disorganized patterns (zig-zag shaped), and organized patterns (for instance, elliptical patterns, and the limits of these patterns, e.g.…”