Abstract
ER body is an ER (endoplasmic reticulum) derived organelle, which might be responsible for a novel defense system, because it is induced by wounding. ER-localized-type GFP, SP-GFP-HDEL, visualizes ER bodies in addition to the ER network. The fluorescent ER bodies are found in the epidermis cells of cotyledons and roots as spindle-shape structures with major axes of approximately 5 micrometers. To reveal control mechanisms for the ER-body morphology, we established a system for quantitative measurement of the ER-body morphology. By using the quantification system, we identified Arabidopsis mutants having abnormally-shaped ER bodies; long ER body mutants (leb) and short ER body mutants (seb).