The Acetate Pathway Supports Flavonoid and Lipid Biosynthesis in Arabidopsis

Abstract

The phenylpropanoid pathway of flavonoid biosynthesis has been the subject of considerable research attention. By contrast, the proposed polyketide pathway, also known as the acetate pathway, which provides malonyl-CoA moieties for the C2 elongation reaction catalyzed by chalcone synthase, is less well studied. Here, we identified four genes as candidates for involvement in the supply of cytosolic malonyl-CoA from the catabolism of acyl-CoA, based on coexpression analysis with other flavonoid-related genes. Two of these genes, ACC and KAT5, have been previously characterized with respect to their involvement in lipid metabolism, but no information concerning their relationship to flavonoid biosynthesis is available. To assess the occurrence and importance of the acetate pathway, we characterized the metabolomes of two mutant or transgenic Arabidopsis lines for each of the four enzymes of this putative pathway using a hierarchical approach covering primary and secondary metabolites as well as lipids. Intriguingly, not only flavonoid content but also glucosinolate content was altered in lines deficient in the acetate pathway, as were levels of lipids and most primary metabolites. We discuss these data in the context of our current understanding of flavonoids and lipid metabolism as well as with regard to improving human nutrition.

Patatin-Related Phospholipase AtpPLAIIIα Affects Lignification of Xylem in Arabidopsis and Hybrid Poplars

“…Lignin provides mechanical reinforcement for a plant to stand upright and enables long-distance water transport [35]. The genes involved in the phenylpropanoid pathway of flavonoid biosynthesis and lipid biosynthesis showed clear functional enrichment, and are supported by the acetate pathway [36]. This suggests that the functional activity of phospholipase involved in lipid metabolism could possibly affect the phenylpropanoid-based polymer-like lignin biosynthesis.…”

Treasure from garden: Bioactive compounds of buckwheat

“…Various flavonol- O -glycosides, including quercitrin, rutin, isoquercitrin, quercetin 3- O -robinobioside, kaempferol 3- O -rutinoside and so on present in buckwheat ( Kiprovski et al, 2015 , Taguchi, 2016 ), therefore buckwheat was used as an ideal plant to investigate the biosynthesis of flavonoids particularly in the old days ( Taguchi, 2016 ). Flavonols and their O -glycosides have a well-organized biosynthesis pathway in different higher plants ( Martin and Li, 2017 , Perez de Souza et al, 2020 ). The rutin biosynthesis initiates from phenylalanine which is deaminated by phenylalanine ammonia-lyase ( PAL ) to form cinnamic acid, followed by a series of reactions catalyzed by cinnamate 4-hydroxylase ( C4H ), 4-coumarate CoA ligase ( 4CL ), chalcone synthase ( CHS ) and chalcone isomerase ( CHI ) ( Davies et al, 2020 , Matsui and Walker, 2019 , Taguchi, 2016 , Yonekura-Sakakibara et al, 2019 ).…”

Metabolomic Characterization of Olive Xylem Sap Reveals Differences According to Plant Age and Genotype

“…Thus, mannitol is known as an osmoregulator being synthesized by plants in response to dehydration conditions [41] and has a remarkable role in protecting plant cells against damage by reactive oxygen species (ROS) [42]. Otherwise, several works have studied the role of glutamine amino acid in the activation of defense responses of the plant against pathogens where the deficit of glutamine is linked to the inhibition of glutamine synthetase complex activating plant defense genes [43,44]; or the antibacterial activity of acetate that supports flavonoid and lipid biosynthesis [45,46]. In relation to ions, K and Clwere the element and inorganic anion more abundant, respectively.…”