Quantitative Measurements of Curvature Along the Growth Axis in Tropic Responses Using Free Software Environments
Tropic responses in plants have usually been studied by measuring changes in the deflection angle of the organ tip. However, the measurement of other geometric parameters, such as curvature along the entire length, may give us better understanding of tropic responses, particularly in shoots. Here, we describe methods for obtaining quantitative measurements of local curvature and other parameters based on digital images of bending Arabidopsis hypocotyls using the free software packages, ImageJ and R.
Key wordsCurvature Curve fit Hypocotyl bending ImageJ Partial derivative of curvature R
This work was funded in part by Grants-in-Aid from Ministry of Education, Culture, Sports, Science, and Technology, Japan, to K. T. Y. (19060008).