Chapter 8 The Methylerythritol 4-Phosphate Pathway: Regulatory Role in Plastid Isoprenoid Biosynthesis

Abstract

Plastids synthesize a variety of isoprenoid compounds that are essential for plant growth and development, like carotenoids, gibberellins, abscisic acid and the side chain of chlorophylls, plastoquinone and toco-pherols. Some plastidial isoprenoids are also relevant for their biotechnological interest The recently elucidated methylerythritol 4-phosphate (MEP) pathway provides the isopentenyl diphosphate and dimethylallyl diphosphate required for the synthesis of plastidial isoprenoids. At present, very little is known about the regulatory mechanisms underlying the control of the metabolic flux through the MEP pathway and its crosstalk with the cytosolic mevalonate (MVA) pathway. Here I summarize recent aspects related to the regulatory role of the MEP pathway in the synthesis of plastidial isoprenoids and the use of reverse genetic strategies to study the crosstalk between the MVA and the MEP pathways.