Complementation of fln1-1 with dexamethasone-inducible FLN1-HA . (A) Complementation of fln1-1 phenotype. BC1 F2 seeds from FLN1/fln1-1 or T3FLN1/fln1-1 FLN1-HA seeds were plated on the indicated concentration of dexamethasone and grown for 7 days at 20o C under constant light. 0 μM is DMSO solvent control. Plates shown are one representative experiment of at least three independent experiments. (B) FLN1-HA induction by dexamethasone in FLN1/fln1-1 FLN1-HA lines. Proteins were extracted from seedlings after 7 days growth, under constant light at 20o C, on GM plates supplemented with indicated concentration of dexamethasone (DEX) and immunoblotted with anti-HA antibodies. Ponceau S stained (PS) membrane is shown as a loading control. Wild-type (wt) plants were green seedlings from a FLN1/fln1-1 parent without the FLN1-HA transgene. Seedlings processed for the “0” treatment for these complementation lines were green siblings (mixed genotype) that segregated with the fln1-1 phenotype in the absence of DEX. Seedlings for other treatments consisted of a pool of all seedlings (all possible genotypes) on the plate (as fln1-1 phenotype was complemented on DEX). The presumed FLN1-HA precursor band is denoted by a double-cross, and the mature, processed FLN-HA by a single-cross. Size markers, in kDa, are to the left of blots. Lines 1, 2, 3 refer to three independent FLN/fln1-1 FLN1-HA lines. Seedlings were F3 seedlings from a FLN/fln1-1 FLN1-HA parental genotype.