Subterranean clover has partial tolerance to the herbicide bromoxynil. This partial tolerance can be enhanced by introducing into subterranean clover, a gene encoding an enzyme capable of de-toxifying the herbicide. This raises the prospect of controlling broad leaf weeds in subterranean clover-based pastures. Bloat safety for forage legumes is also being pursued by using genetic engineering to increase the levels of condensed tannins in leaves. Bloat results when animals feed on pastures with a high proportion of protein in the soft-celled leaves of plants such as lucerne and white clover.
Bloat is responsible for substantial losses to the meat and dairy industries.
When the forage includes leaves containing condensed tannin, the ruminal bloaty foam is prevented. The biosynthetic pathway for condensed tannin and the regulation of that pathway is being explored. Genes involved in tannin synthesis are being sought for transfer to lucerne and white clover. Tannin accumulating transgenic lines of these important forage and feed legumes would be bloat safe and could have higher levels of by-pass protein. A robust system for wheat is under development.