FRUITFULL

FRUITFULL, also called FUL or AGL8, is an Arabidopsis thaliana developmental regulatory gene encoding a MADS-box transcription factor. In the fruit, it helps establish normal valve tissue identity. The gene, its protein product and a mutant plant's phenotype are different levels of description.

The 1998 study of the ful-1 mutant identified an inserted enhancer-trap element disrupting the gene. A reporter marked valve tissue, and mutant valve cells failed to elongate and differentiate normally.^[ref] Comparing local expression and cell anatomy supplies more mechanistic information than noting only that a mature fruit is short.

A later genetic analysis clarified that the effect need not mean that FRUITFULL directly drives every elongation step. Its regulatory role includes preventing misplaced INDEHISCENT activity.^[ref] In a causal comparison, defective growth machinery and altered tissue identity can both produce a short organ. Perturbing the regulatory pathway and measuring which identity develops helps distinguish those explanations. The combined history connects gene expression, cell differentiation, fruit dehiscence and seed dispersal without treating final organ length as a direct assay of a single molecular function.