Analysis of movement in primary maize roots

Studying plant root kinematics is important for understanding certain aspects of root growth and movement, which are strictly correlated in plants. However, there is little available data on autonomous movements in plant roots, such as nutations, and the data that are available are poorly described. We investigated the autonomous movements during growth in primary maize roots by estimating the main kinematic parameters of nutations (i.e., the period of duration and amplitude) and the growth rate. The estimations of nutation parameters were performed by developing dedicated methods, which are based on the analysis of root tip displacement and tip velocity. The data relative to the tip displacements were obtained using tip tracing software developed by our team specifically for this purpose. The results confirmed that the nutational phenomenon covers the continuous range of periods and amplitudes, with certain dominant period-amplitude types, which we clustered into three groups: i) amplitudes less than 0.1 mm and 4–16 min periods, ii) amplitudes less than 0.1 mm and 20–120 min periods, and iii) amplitudes greater than 0.1 mm and 24–120 min periods.