Figure 7.

thi2-blk1 Mutants Are Thiamine Auxotrophs

(A) HPLC analysis of THI2 (blue), THI2-blk1 (green), and yeast THI4 (orange) protein-bound metabolites. THI2, but not THI2-blk1 protein, copurifies with bound ADT substrate. GI, glycine-imine; TT, thiazole tautomer. AU, absorbance units.

(B) to (E) Thiamine treatment rescues blk1-R phenotypes. Untreated thi2-blk1 plant with reduced leaf blade (arrow) (B) and aborted shoot apex (C). Treated thi2-blk1 mutant plant showing rescued leaves (D) and tassel inflorescence (E).

Bars = 7 cm ([B] and [D]) and 500 μm ([C] and [E]).