LeafJ: an ImageJ plugin for semi-automated leaf shape measurement.

Area of Science:

• Plant biology
• Genetics
• Computational biology

Background:

• High-throughput phenotyping (phenomics) is crucial for linking genes to plant functions.
• Leaf morphology, including petiole length and blade area, is vital for understanding plant responses to environmental cues like shade.
• Existing leaf analysis software lacks the ability to measure petiole length, hindering research on the shade avoidance syndrome (SAS).

Purpose of the Study:

• To develop and validate a novel ImageJ plugin, LeafJ, for rapid and accurate measurement of leaf petiole length and blade parameters.
• To present a complementary protocol for measuring leaf cell shape, area, and size using a touch-screen tablet.
• To facilitate large-scale phenomics approaches in plant research, especially for SAS studies.

Main Methods:

• Development of the LeafJ ImageJ plugin for automated measurement of leaf traits.
• Utilized a touch-screen tablet for manual correction and measurement of leaf cell characteristics.
• Tested the system on the model plant Arabidopsis thaliana.

Main Results:

• LeafJ enables rapid measurement of petiole length and leaf blade parameters, addressing a key limitation in existing phenotyping tools.
• The touch-screen tablet protocol allows for efficient measurement of leaf cell shape, area, and size.
• The developed system significantly enhances the capacity for large-scale leaf phenotyping.

Conclusions:

• The LeafJ plugin and associated tablet protocol provide a powerful new system for comprehensive leaf phenotyping.
• This advancement will accelerate research in plant genetics, environmental responses (e.g., SAS), and crop improvement.
• The tools are versatile and applicable to a wide range of plant phenomics studies beyond shade avoidance.