Metabolic engineering to increase isoflavone biosynthesis in soybean seed

• Published in: Phytochemistry (Oxford) 2003-08, Vol.63 (7), p.753-763
• Main Authors: Yu, Oliver, Shi, June, Hession, Aideen O., Maxwell, Carl A., McGonigle, Brian, Odell, Joan T.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Biotechnology; Fabaceae; Flavanone 3-Hydroxylase; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Genetic Engineering; Genetic technics; Genetics and breeding of economic plants; Glycine max; Glycine max - metabolism; Isoflavone; Isoflavones - metabolism; Methods. Procedures. Technologies; Molecular Structure; Phenotype; Seeds - metabolism; Signal Transduction; Transcription Factor; Transcription Factors - genetics; Transcription Factors - metabolism; Transcriptional Activation; Transgenic animals and transgenic plants; Transgenic plants; Varietal selection. Specialized plant breeding, plant breeding aims; Yield, quality, earliness, varia
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/S0031-9422(03)00345-5

Isoflavone levels in Glycine max (soybean) were increased via metabolic engineering of the complex phenylpropanoid biosynthetic pathway. Phenylpropanoid pathway genes were activated by expression of the maize C1 and R transcription factors in soybean seed, which decreased genistein and increased the daidzein levels with a small overall increase in total isoflavone levels. Cosuppression of flavanone 3-hydroxylase to block the anthocyanin branch of the pathway, in conjunction with C1/R expression, resulted in higher levels of isoflavones. The combination of transcription factor-driven gene activation and suppression of a competing pathway provided a successful means of enhancing accumulation of isoflavones in soybean seed. The combination of transcription factor-driven gene activation and suppression of a competing pathway enhances accumulation of isoflavones in soybeans.