Monoterpene biosynthesis potential of plant subcellular compartments

Abstract

SummarySubcellular monoterpene biosynthesis capacity based on local geranyl diphosphate (GDP) availability or locally boosted GDP production was determined for plastids, cytosol and mitochondria.A geraniol synthase (GES) was targeted to plastids, cytosol, or mitochondria. Transient expression in Nicotiana benthamiana indicated local GDP availability for each compartment but resulted in different product levels. A GDP synthase from Picea abies (PaGDPS1) was shown to boost GDP production. PaGDPS1 was also targeted to plastids, cytosol or mitochondria and PaGDPS1 and GES were coexpressed in all possible combinations.Geraniol and geraniol-derived products were analyzed by GC-MS and LC-MS, respectively. GES product levels were highest for plastid-targeted GES, followed by mitochondrial-and then cytosolic-targeted GES. For each compartment local boosting of GDP biosynthesis increased GES product levels.GDP exchange between compartments is not equal: while no GDP is exchanged from the cytosol to the plastids, 100% of GDP in mitochondria can be exchanged to plastids, while only 7% of GDP from plastids is available for mitochondria. This suggests a direct exchange mechanism for GDP between plastids and mitochondria. Cytosolic PaGDPS1 competes with plastidial GES activity, suggesting an effective drain of isopentenyl diphosphate from the plastids to the cytosol.

Integrating pathway elucidation with yeast engineering to produce polpunonic acid the precursor of the anti-obesity agent celastrol

“…A possible downside of the approach can be the ability of endogenous tobacco enzymes to further modify the enzymatic products. For example, it is established that tobacco often glycosylates products of heterologous enzymes resulting in a multitude of glycoside products [61]. This can be circumvented by the use of glycosylase formulations, such as Viscozyme (Sigma-Aldrich) to deglycosylate the compounds to their original form prior to analysis.…”

Glucosylation of the phytoalexin N‐feruloyl tyramine modulates the levels of pathogen‐responsive metabolites in Nicotiana benthamiana

“…These studies have shown that numerous endogenous Nicotiana metabolites are decorated with sugars (Kodama et al, 1984;Pang et al, 2007;Jassbi et al, 2010;Heiling et al, 2016;Yuan et al, 2018) and newly formed metabolites are subjected to glycosylation (Dong et al, 2013(Dong et al, , 2016. The glycosylation reactions are catalyzed by uridine diphosphate dependent glycosyltransferases (UGT) that transfer carbohydrates from nucleotide-sugar donors (e.g.…”

Strategies for the production of biochemicals in bioenergy crops

“…Similarly, in Catharanthus roseus, accumulation of secologanin, a geraniol derived-monoterpene indole alkaloid, was achieved upon overexpression of CrGES along with a bifunctional CrG(G)PPS [259,260]. In addition, a combinatorial production of geraniol in tobacco has been examined using different subcellular compartments (i.e., plastids, cytosol or mitochondria): results showed that plastid-targeted VoGES combined with expression GPPS from Picea abies (PaGDPS1) for GPP overproduction lead to the highest production of geraniol [261].…”