FACKEL mutants exhibit:
FACKEL encodes sterol C-14 reductase integral to phytosterol and brassinosteroid biosynthetic pathway converting 4α-methylsterol intermediates like foliasterol into functional bulk sterols sitosterol, campesterol, and brassinolide. Sterols govern membrane fluidity, lipid raft organization, and polar targeting of PIN auxin carriers and cellulose synthases. fackel-J79 dwarf mutants resemble brassinosteroid-deficient mutants yet additionally exhibit severe embryonic patterning defects: enlarged, fused, or supernumerary cotyledons, ectopic shoot meristems, and stunted roots. This demonstrates ster
Ref: Jang et al., Genes Dev 2000; Schrick et al., Plant Cell 2004: FACKEL encodes sterol C-14 reductase, mutants show cotyledon defects.