Anthocyanin Synthesis in Corn Endosperm Tissue Cultures. I. Identity of the Pigments and General Factors.

Abstract

There are at least 3 pigments produced by these tissue cultures. Two of them have been identified as cyanidin-3-monoglucoside and pelargonidin-3-monoglucoside. The 3d is present in trace amounts and was not identified. The absorption spectra of these pigments were determined using 2% HC1 in 95% ethanol (v/v). The cyanidin derivative has peaks at 272 m[mu] and at 540 m[mu]. The pelargonidin derivative has peaks at 275 m[mu] and at 520 m[mu]. In general acid media have small promotive effects on pigment production, but alkaline media have a definitely inhibitory effect. It is suggested that the latter is due to the unavailability of copper or other mineral nutrients in alkaline media. Sucrose, on a molar basis, permits greater pigment synthesis than either glucose or fructose. Increased concentrations of sucrose from 0.05 [image] to 0.20 [image] have rather small effects on increasing pigment production. Light is essential for the synthesis of anthocyanin by these tissues. When grown in the dark, the tissue is virtually colorless. Such tissue shows visible signs of pigmentation after 6 hours exposure to light. It is suggested as one possibility that precursors are produced in the dark which require a photochemical reaction in order to be transformed into anthocyanin.