Molecular Biology of Plant Pathways / Genetic Engineering of Amino Acid Metabolism in Plants
Summary
Apart from serving as protein building blocks, amino acids play multiple regulatory
roles in plant growth, including nitrogen assimilation and transport,
carbon/nitrogen balance, production of hormones and secondary metabolites,
stress-associated metabolism, and many other processes. Some of the amino
acids are of particular importance not only for plant growth but also for the
nutritional quality of plant foods and feeds because human and its ruminant
and nonruminant livestock cannot synthesize them and depend on their availability
in their diets. Genetic and metabolic engineering approaches have contributed
tremendously to the understanding of the regulation of amino acid metabolism in
plants. This chapter discusses how amino acid metabolism is regulated by complex
regulatory networks that operate in concert with other regulatory networks
of carbon and likely also lipid metabolism. These networks are, however, also
subjected to concerted spatial, temporal, developmental, and environmental controls.
The combined application of genomic, proteomic, and metabolomic
approaches coupled with genetic and metabolic engineering, as well as analysis
of dynamic fluxes in different intracellular organelles, offers a promising future
for the dissection of these compound regulatory networks.