Structure and Dynamics of the Isoprenoid Pathway Network

Abstract

Isoprenoids are functionally and structurally the most diverse group of plant metabolites reported to date. They can function as primary metabolites, participating in essential plant cellular processes, and as secondary metabolites, of which many have substantial commercial, pharmacological, and agricultural value. Isoprenoid end products participate in plants in a wide range of physiological processes acting in them both synergistically, such as chlorophyll and carotenoids during photosynthesis, or antagonistically, such as gibberellic acid and abscisic acid during seed germination. It is therefore expected that fluxes via isoprenoid metabolic network are tightly controlled both temporally and spatially, and that this control occurs at different levels of regulation and in an orchestrated manner over the entire isoprenoid metabolic network. In this review, we summarize our current knowledge of the topology of the plant isoprenoid pathway network and its regulation at the gene expression level following diverse stimuli. We conclude by discussing agronomical and biotechnological applications emerging from the plant isoprenoid metabolism and provide an outlook on future directions in the systems analysis of the plant isoprenoid pathway network.

Comprehensive Tissue-Specific Transcriptome Analysis Reveals Distinct Regulatory Programs during Early Tomato Fruit Development

“…Cluster 30, which comprised genes primarily expressed in the pericarp, had overrepresentation of genes from the transport, secondary metabolism, and hormone-related categories and contained many genes involved in isoprenoid biosynthesis and the production of steroid precursors in a variety of biosynthetic pathways (Vranová et al, 2012). Several of the genes in the hormone-related category were part of the connected brassinosteroid biosynthetic pathway, in which cycloartenol, an isoprenoid-derived steroid, is the starting point (Ohyama et al, 2009).…”

Controlled biosynthesis of odd-chain fuels and chemicals via engineered modular metabolic pathways

“…These compounds can be further modified by several decorating enzymes to yield an enormous array of products that exert physiological functions. For example, a few prenyl diphosphates produced from two simple isoprene units through the central isoprenoid pathway can be modified into over 50,000 functionally diverse isoprenoids by terpene-modifying enzymes (1,2) (Fig. 1A).…”

Volatile terpenoids: multiple functions, biosynthesis, modulation and manipulation by genetic engineering

“…The condensation of one IPP with one GPP molecule produces farnesyl pyrophosphate (FPP), which is catalyzed in the presence of FPP synthases (FPS). Similarly, GPP and FPP are precursors for the biosynthesis of monoterpenes and sesquiterpenes, respectively (Vranová et al 2012), whereas prenyl diphosphates in the trans-configuration are assumed to be the ubiquitous naturally occurring substrates for terpene synthases. In wild-type tomato trichomes, Z, Z-FPP and two prenyl diphosphates, in the cis-configuration, are also naturally occurring substrates for the synthesis of sesquiterpenes catalyzed by FPP synthase (zFPS).…”

“…Plant genomes have evolved to encode diverse FPP synthase isoforms, which are present in the cytosol, mitochondria, plastids or peroxisomes Thabet et al 2012). Terpene biosynthesis occurs at specific stages during plant development and within specific tissues (Vranová et al 2012).…”

“…The biosynthesis and regulation of emission of plant terpenoids are mostly carried out via petals, although other tissues, such as sepals, stamens, pistils and nectaries, also contribute to the floral bouquet of plant species (Farré-Armengol et al 2013). Sometimes, the regulation of terpenoids is induced via abiotic stresses, pathogens attack or feeding of herbivores (Vranová et al 2012). In Arabidopsis, mono-and sesquiterpene synthases are not expressed in flower petals, and their expression is restricted to nectaries, sepals, anthers and stigma (Tholl et al 2005).…”