Details

Autor(en) / Beteiligte

• Zhu, Changfu
• Naqvi, Shaista
• Breitenbach, Jürgen
• Sandmann, Gerhard
• Christou, Paul
• Capell, Teresa

Titel

Combinatorial genetic transformation generates a library of metabolic phenotypes for the carotenoid pathway in maize

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 2008-11, Vol.105 (47), p.18232-18237

Ort / Verlag

United States: National Academy of Sciences

Erscheinungsjahr

2008

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Combinatorial nuclear transformation is a novel method for the rapid production of multiplex-transgenic plants, which we have used to dissect and modify a complex metabolic pathway. To demonstrate the principle, we transferred 5 carotenogenic genes controlled by different endosperm-specific promoters into a white maize variety deficient for endosperm carotenoid synthesis. We recovered a diverse population of transgenic plants expressing different enzyme combinations and showing distinct metabolic phenotypes that allowed us to identify and complement rate-limiting steps in the pathway and to demonstrate competition between β-carotene hydroxylase and bacterial β-carotene ketolase for substrates in 4 sequential steps of the extended pathway. Importantly, this process allowed us to generate plants with extraordinary levels of β-carotene and other carotenoids, including complex mixtures of hydroxycarotenoids and ketocarotenoids. Combinatorial transformation is a versatile approach that could be used to modify any metabolic pathway and pathways controlling other biochemical, physiological, or developmental processes.