The rnt1-1 phenotype induced by knock-out of CYP83B1. Reprinted from Bak and Feyereisen (2001).
(A) 1 week old rnt1-1 seedlings have increased hypocotyl length and epinastic cotyledons.
(B) After two weeks, exfoliation of the hypocotyl begins at the root-hypocotyl junction (-,). Secondary roots initiate from the hypocotyl, and there is an enhanced formation of secondary roots and root hairs.
(C) 6 weeks old rnt1-1 plants have increased apical dominance due to elevated IAA levels. Typically, the plants have a reduced height, an increased number of epinastic rosette leaves and a single inflorescence.