Journal Article

Reprogramming the Phenylpropanoid Metabolism in Seeds of Oilseed Rape by Suppressing the Orthologs of REDUCED EPIDERMAL FLUORESCENCE1

Mittasch, Juliane, Frolov, Andrej, Milkowski, Carsten, Strack, Dieter, Böttcher, Christoph

2013

Overview

As a result of the phenylpropanoid pathway, many Brassicaceae produce considerable amounts of soluble hydroxycinnamate conjugates, mainly sinapate esters. From oilseed rape (Brassica napus), we cloned two orthologs of the Arabidopsis (Arabidopsis thaliana) gene REDUCED EPIDERMAL FLUORESCENCE1 (REF1) encoding a coniferaldehyde/sinapaldehyde dehydrogenase. The enzyme is involved in the formation of ferulate and sinapate from the corresponding aldehydes, thereby linking lignin and hydroxycinnamate biosynthesis as a potential branch-point enzyme. We used RNA interference to silence REF1 genes in seeds of oilseed rape. Nontargeted metabolite profiling showed that BnREF1-suppressing seeds produced a novel chemotype characterized by reduced levels of sinapate esters, the appearance of conjugated monolignols, dilignols, and trilignols, altered accumulation patterns of kaempferol glycosides, and changes in minor conjugates of caffeate, ferulate, and 5-hydroxyferulate. BnREF1 suppression affected the level of minor sinapate conjugates more severely than that of the major component sinapine. Mapping of the changed metabolites onto the phenylpropanoid metabolic network revealed partial redirection of metabolic sequences as a major impact of BnREF1 suppression.

• Publisher: American Society of Plant Biologists
• Subject: Alcohols / aldehyde dehydrogenase / Aldehyde Dehydrogenase - chemistry / BIOCHEMISTRY AND METABOLISM / Biological and medical sciences / Biosynthetic Pathways / Blotting, Southern / Brassica napus / Brassica napus - enzymology / Brassica napus - genetics / Brassica napus - metabolism / Choline - analogs & derivatives / Choline - analysis / Chromatography, High Pressure Liquid / Complementary DNA / Crosses, Genetic / DNA / Esters / Esters - chemistry / Esters - metabolism / Fundamental and applied biological sciences. Psychology / Genes, Plant - genetics / Genome, Plant - genetics / Genomics / Homozygote / Metabolism / Metabolites / Metabolome / Molecular Sequence Data / Oilseeds / Plant physiology and development / Plant Proteins - metabolism / Plants, Genetically Modified / Polymerase chain reaction / Propanols - metabolism / Seeds / Seeds - metabolism / Sequence Homology, Amino Acid