| 摘要 |
This invention relates to an isolated nucleic acid fragment encoding a plant enzyme that catalyze steps in the biosynthesis of lysine, threonine, methionine, cysteine and isoleucine from aspartate, the enzyme being a member selected from the group consisting of aspartic semialedhyde dehydrogenase, diaminopimelate decarboxylase, homoserine kinase, cysteine synthase and cystathionine beta -lyase. The invention also relates to the construction of a chimeric gene encoding all or a portion of the enzyme, in sense or antisense orientation, wherein expression of the chimeric gene results in production of altered levels of the enzyme in a transformed host cell. |
