Inhibition of Anthocyanin Synthesis by Cobaltous Ions in the First Internode ofSorghum bicolorL. Moench

Abstract

Cobaltous ions (Co²⁺) inhibited light-mediated anthocyanin synthesis in excised first internodes of Sorghum bicolor (L.) Moench. Studies with precursors/intermediates of the anthocyanin biosynthetic pathway, such as acetate, phenylalanine, t-cinnamic acid, tyrosine, and p-coumaric acid were undertaken to identify the metabolic site at which Co²⁺ ions inhibit anthocyanin synthesis. p-Coumaric acid partially restored anthocyanin synthesis. No other intermediate was effective in bringing about recovery. It is suggested that Co²⁺ might interfere with process/es which leads to the formation of p-coumaric acid, an intermediate of the anthocyanin biosynthetic pathway.