Gibberellins (GA) were first isolated from the fungus Gibberella fujikuroi, the causal organism of foolish seedling disease of rice plants, by Kurasawa in Japan in 1926. Abscisic acid was first identified and isolated chemically from cotton plants. Auxin was discovered during the study of bending of the coleoptile of canary grass (Phalaris canariensis) towards light. 2,4-D is an herbicide that kills plants by changing the way certain cells grow.