Soybean gets protein lift

Soybeans are a highly nutritious, protein-rich food source. However, they have lower amounts of the amino acids methionine and cysteine, both of which are essential to human and animal growth and development.

To supplant this deficiency, genes which express methionine and cyteine-rich proteins may be introduced into soybean. Zhiwu Li, of Kansas State University, and colleagues explore this option as they induce the "High level expression of maize c-zein protein in transgenic soybean (Glycine max.)." Their work appears in the latest issue of Molecular Breeding.

Researchers introduced the maize-derived, c-zein gene into the Jack soybean cultivar. C-zein produces a sulfur-rich protein, which also contains methionine and cysteine. Their techniques yielded three transgenic lines, two of which showed significant cysteine and methionine content upon protein extraction and assaying of the grown plants' seed flour.

These two transgenic lines produced as much as 30% more cysteine, and 18.6% more methionine than the Jack cultivar. The two transgenic cultivars also stably passed the c-zein gene on to subsequent soybean generations.

Subscribers to Molecular Breeding may download the complete article at http://dx.doi.org/10.1007/s11032-004-7658-6. Other readers may view the abstract at the same site.

Source: CropBiotech Update