Figure 1.
Elicitation of glyceollins in soybean roots by pH 3.0 medium. (a) Seven-day-old seedlings were transferred to pH 5.8 or pH 3.0 medium for 9 d, or exposed to a 30 W UV-C lamp for 1 h daily. Metabolites were extracted from intact seedlings (a) or dissected organs (b) by 80% ethanol and were quantified by UPLC-PDA by comparison to purified standards. (c) Root color phenotypes following 9 days treatment with pH 5.8 or pH 3.0 medium. (d) UPLC-PDA chromatograms of isoflavonoid extracts from cotyledons, leafs, hypocotyls and roots of Harosoy 63 seedlings elicited with pH 3.0 medium for 9 d. Peaks: 1) daidzin, 2) 6-O-malonyldaidzin, 3) 6-O-malonylgenistin, 4) daidzein, 5) genistein, 6) glyceollin III, 7) glyceollin II, 8) glyceollin I and 9) βprenyl-genistein.