RootIX: An Easy and Ready to Use Tool for the Study of Plant Root Growth and Architecture.

Abstract Background: Agronomical and plant physiological studies employ a large variety of compounds that impact root development. The effect of these compounds is often evaluated by root architecture analyses using dedicated software. During the past decade, a growing number of tools proposed complex and deep analysis of the root system architecture. While these software applications are often complex and require specific set up, here, we propose a simple method based on the most common tools used by biologists: ImageJ and Excel®.Results: First, roots are measured manually with ImageJ following a succession of operations (i. choose a plant; ii. Measure: a. the primary root - b. lateral roots). Secondly, RootIX, an Excel file with dedicated macros that will automatically extract, sort and treat the data, is launched. Tables and graphics describing the data are generated. Root length, elongation rate and additional lateral roots are the main indicators provided among many others. We evaluated the effect of algae extracts on tomato roots growth with RootIX. We highlighted that these compounds negatively affect root growth while promoting generation of lateral roots.Conclusion: Ease of use and settings as well as complete data analyses without any cost are the scaffold of RootIX.