Mechanisms of development can be investigated through mutants defective in the process

Tonneau (ton) mutation causes: disorganised cell division. gnom mutation: lack apical-basal polarity. It encodes a protein with a role in the secretory pathway. There is abnormal localisation of PIN1, a transporter for the hormone auxin. Shortroot (shr) and scarecrow (scr) mutants: both lack one cell layer, the endodermis.