Figure 9.

Metabolite Complementation Analysis of the bat5 Mutant.

(A) Met-derived amino acids and the corresponding 2-keto acids. Chain-elongation of 2-keto acids proceeds in plastids, and the transamination reactions are catalyzed by BCATs. Homomethionine/MTOP and dihomomethionine/MTOH are converted to the Met-derived GSs 3MSOP and 4MSOB, respectively.

(B) to (I) Two-week-old seedlings were fed with 2-keto acids or amino acids on MS plates. Feeding was performed with MTOB, MTOP, and MTOH ([B] to [E]) and Met and dihomomethionine (DiHoMet) ([F] to [I]). Means ± sd (n = 5). Contents of short- and long-chained aliphatic GSs (3MSOP, 4MSOB, 5MSOP, 6MSOH, 7MSOH, 7MTH, and 8MSOO) are given in nmol/mg dry weight in comparison with Col-0. Asterisk indicates significant difference in comparison to the wild type or bat5, respectively (Student's t test, P < 0.05). Plants were germinated on half-strength Murashige and Skoog (MS) plates with agar, and 2-week-old wild-type and bat5 seedlings were transferred to media supplemented with 0.2 mM MTOB, MTOP, MTOH, Met, or dihomomethionine, respectively, for 14 additional days, followed by analyses of aliphatic GSs.