Metabolic engineering of plants for osmotic stress resistance.

Genes encoding critical steps in the synthesis of osmoprotectant compounds are now being expressed in transgenic plants. These plants generally accumulate low levels of osmoprotectants and have increased stress tolerance. The next priority is therefore to engineer greater osmoprotectant synthesis without detriment to the rest of metabolism. This will require manipulation of multiple genes, guided by thorough analysis of metabolite fluxes and pool sizes.