In planta production of the nylon precursor beta-ketoadipate.

Beta-ketoadipate (βKA) is an intermediate of the βKA pathway involved in the degradation of aromatic compounds in several bacteria and fungi. Beta-ketoadipate also represents a promising chemical for the manufacturing of performance-advantaged nylons. We established a strategy for the in planta synthesis of βKA via manipulation of the shikimate pathway and the expression of bacterial enzymes from the βKA pathway.

Identification of a promoter region specifically active in the maturing endosperm of Arabidopsis seeds and its use for targeted modification of fatty acid metabolism.

In angiosperm seeds, the relative proportions of the two zygotic tissues vary considerably from species to species. In many field-grown oilseed species, and in those of the model species Arabidopsis thaliana, the embryo predominates, and studies of lipid metabolism in whole seeds reflect embryonic metabolism. Metabolism in the endosperm has long been ignored in these species, where this tissue is reduced in size in the mature seed.

Plant monounsaturated fatty acids: Diversity, biosynthesis, functions and uses.

Monounsaturated fatty acids are straight-chain aliphatic monocarboxylic acids comprising a unique carbon‑carbon double bond, also termed unsaturation. More than 50 distinct molecular structures have been described in the plant kingdom, and more remain to be discovered. The evolution of land plants has apparently resulted in the convergent evolution of non-homologous enzymes catalyzing the dehydrogenation of saturated acyl chain substrates in a chemo-, regio- and stereoselective manner.

Acyl-Acyl Carrier Protein Desaturases and Plant Biotic Interactions.

Interactions between land plants and other organisms such as pathogens, pollinators, or symbionts usually involve a variety of specialized effectors participating in complex cross-talks between organisms. Fatty acids and their lipid derivatives play important roles in these biological interactions. While the transcriptional regulation of genes encoding acyl-acyl carrier protein (ACP) desaturases appears to be largely responsive to biotic stress, the different monounsaturated fatty acids produced by these enzymes were shown to take active part in plant biotic interactions and were assigned with specific functions intrinsically linked to the position of the carbon-carbon double bond within their acyl chain.

Molecular Control of Oil Metabolism in the Endosperm of Seeds.

In angiosperm seeds, the endosperm develops to varying degrees and accumulates different types of storage compounds remobilized by the seedling during early post-germinative growth. Whereas the molecular mechanisms controlling the metabolism of starch and seed-storage proteins in the endosperm of cereal grains are relatively well characterized, the regulation of oil metabolism in the endosperm of developing and germinating oilseeds has received particular attention only more recently, thanks to the emergence and continuous improvement of analytical techniques allowing the evaluation, within a spatial context, of gene activity on one side, and lipid metabolism on the other side. These studies represent a fundamental step toward the elucidation of the molecular mechanisms governing oil metabolism in this particular tissue.

Differential Activation of Partially Redundant Δ9 Stearoyl-ACP Desaturase Genes Is Critical for Omega-9 Monounsaturated Fatty Acid Biosynthesis During Seed Development in Arabidopsis.

The spatiotemporal pattern of deposition, final amount, and relative abundance of oleic acid (-ω-9 C18:1) and its derivatives in the different lipid fractions of the seed of Arabidopsis () indicates that omega-9 monoenes are synthesized at high rates in this organ. Accordingly, we observed that four Δ9 stearoyl-ACP desaturase (SAD)-coding genes ( [], [], , and ) are transcriptionally induced in seeds. We established that the three most highly expressed ones are directly activated by the WRINKLED1 transcription factor.