A critical role of sterols in embryonic patterning and meristem programming revealed by the fackel mutants of Arabidopsis thaliana
2000; Cold Spring Harbor Laboratory Press; Volume: 14; Issue: 12 Linguagem: Inglês
10.1101/gad.14.12.1485
ISSN1549-5477
AutoresJyan-Chyun Jang, Shozo Fujioka, Masao Tasaka, Hideharu Seto, Suguru Takatsuto, Akira Ishii, Mitsuhiro Aida, Shigeo Yoshida, Jen Sheen,
Tópico(s)Lipid metabolism and biosynthesis
ResumoHere we report a novel Arabidopsis dwarf mutant, fackel-J79 , whose adult morphology resembles that of brassinosteroid-deficient mutants but also displays distorted embryos, supernumerary cotyledons, multiple shoot meristems, and stunted roots. We cloned the FACKEL gene and found that it encodes a protein with sequence similarity to both the human sterol reductase family and yeast C-14 sterol reductase and is preferentially expressed in actively growing cells. Biochemical analysis indicates that the fk-J79 mutation results in deficient C-14 sterol reductase activity, abnormal sterol composition, and reduction of brassinosteroids (BRs). Unlike other BR-deficient mutants, the defect of hypocotyl elongation in fk-J79 cannot be corrected by exogenous BRs. The unique phenotypes and sterol composition in fk-J79 indicate crucial roles of sterol regulation and signaling in cell division and cell expansion in embryonic and post-embryonic development in plants.
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