Expression of a bacterial feedback‐insensitive 3‐deoxy‐d‐arabino‐heptulosonate 7‐phosphate synthase of the shikimate pathway in Arabidopsis elucidates potential metabolic bottlenecks between primary and secondary metabolism

Abstract

Summary• The shikimate pathway of plants mediates the conversion of primary carbon metabolites via chorismate into the three aromatic amino acids and to numerous secondary metabolites derived from them. However, the regulation of the shikimate pathway is still far from being understood. We hypothesized that 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHPS) is a key enzyme regulating flux through the shikimate pathway.• To test this hypothesis, we expressed a mutant bacterial AroG gene encoding a feedbackinsensitive DAHPS in transgenic Arabidopsis plants. The plants were subjected to detailed analysis of primary metabolism, using GC-MS, as well as secondary metabolism, using LC-MS.• Our results exposed a major effect of bacterial AroG expression on the levels of shikimate intermediate metabolites, phenylalanine, tryptophan and broad classes of secondary metabolite, such as phenylpropanoids, glucosinolates, auxin and other hormone conjugates.• We propose that DAHPS is a key regulatory enzyme of the shikimate pathway. Moreover, our results shed light on additional potential metabolic bottlenecks bridging plant primary and secondary metabolism.

Transcriptome profiling provides new insights into the formation of floral scent in Hedychium coronarium

“…8. Among them, DAHPS is the first committed enzyme in shikimate pathway and controls the overall carbon flux into the pathway [64]. The HcDAHPS1 gene displayed a very high expression level during the petal development, while the expression level of HcDAHPS2 was low, suggesting that HcDAHPS1 play a key role in regulating the carbon flux into the shikimate pathway.…”

“…DAHPS represents the first committed enzyme and controls the overall carbon flux into the pathway [64]. Petunia contains two DAHPSs.…”

Identification and analysis of genes associated with the synthesis of bioactive constituents in Dendrobium officinale using RNA-Seq

“…The expression patterns of the unigenes annotated as elements of TIA biosynthesis were analyzed using the transcriptome data. The productions of the shikimate pathway in plants are not only essential components of protein synthesis, but are also precursors for a wide range of secondary metabolites 28, 29 . SHKG is a shikimate pathway key enzyme involved in the formation of enolpyruvylshikimate 3-phosphate 30 .…”

An insight into conflux of metabolic traffic leading to picroside-I biosynthesis by tracking molecular time course changes in a medicinal herb, Picrorhiza kurroa

“…The elevated expression of G-6-PDH gene resulting in activation of the pentose phosphate pathway, which might produce higher levels of erythrose-4-phosphate. The later one is the substrate for the enzyme DAHPS, considered to be rate-limiting enzyme of the shikimate/phenylpropanoid pathway (Tzin et al 2012). Further, PAL is supposed to be the entry point into P-I biosynthesis via the formation of cinnamoyl CoA Gahlan et al 2012).…”