Metabolic engineering and profiling of rice with increased lysine.

Publisher: Wiley on behalf of the Society for Experimental Biology, Association of Applied Biologists Country of Publication: England NLM ID: 101201889 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1467-7652 (Electronic) Linking ISSN: 14677644 NLM ISO Abbreviation: Plant Biotechnol J Subsets: MEDLINE

Publication: 2014- : Oxford Wiley on behalf of the Society for Experimental Biology, Association of Applied Biologists
Original Publication: [Oxford] : Blackwell Pub., c2003-

Lysine/*metabolism ; Metabolic Engineering/*methods ; Oryza/*metabolism ; Plants, Genetically Modified/*metabolism; Gene Expression Regulation, Plant/genetics ; Gene Expression Regulation, Plant/physiology ; Oryza/genetics ; Plants, Genetically Modified/genetics

Lysine (Lys) is the first limiting essential amino acid in rice, a stable food for half of the world population. Efforts, including genetic engineering, have not achieved a desirable level of Lys in rice. Here, we genetically engineered rice to increase Lys levels by expressing bacterial lysine feedback-insensitive aspartate kinase (AK) and dihydrodipicolinate synthase (DHPS) to enhance Lys biosynthesis; through RNA interference of rice lysine ketoglutaric acid reductase/saccharopine dehydropine dehydrogenase (LKR/SDH) to down-regulate its catabolism; and by combined expression of AK and DHPS and interference of LKR/SDH to achieve both metabolic effects. In these transgenic plants, free Lys levels increased up to ~12-fold in leaves and ~60-fold in seeds, substantially greater than the 2.5-fold increase in transgenic rice seeds reported by the only previous related study. To better understand the metabolic regulation of Lys accumulation in rice, metabolomic methods were employed to analyse the changes in metabolites of the Lys biosynthesis and catabolism pathways in leaves and seeds at different stages. Free Lys accumulation was mainly regulated by its biosynthesis in leaves and to a greater extent by catabolism in seeds. The transgenic plants did not show observable changes in plant growth and seed germination nor large changes in levels of asparagine (Asn) and glutamine (Gln) in leaves, which are the major amino acids transported into seeds. Although Lys was highly accumulated in leaves of certain transgenic lines, a corresponding higher Lys accumulation was not observed in seeds, suggesting that free Lys transport from leaves into seeds did not occur.
(© 2012 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.)

K3Z4F929H6 (Lysine)

Date Created: 20130103 Date Completed: 20131104 Latest Revision: 20151119

20221213

10.1111/pbi.12037

23279104