Light and Methyl Jasmonate Impact in the Biosynthesis of Anthocyanins and VLCFAs in the Euonymus maximowiczianus Aril-Derived Long-Term Suspension-Cultured Cells

The genus Euonymus (L.) consists of shrubs or woody plants, distributed mainly in the Northern Hemisphere. To date, from Euonymus spp. several hundreds of different secondary metabolites have been isolated and identified. In addition, fatty oil was found in the fruits of some species of these plants, which accumulates not only in the seeds, but also in the arils. This study presents the research of unique long-term (ten-year-old) suspension cell cultures of Euonymus maximoviczianus Prokh. which were obtained from arils of unripe capsules. Suspension cells retain the ability to form oil droplets containing neutral lipids, both in the dark and in the light, the cells are able to synthesize very-long-chain fatty acids (VLCFAs), and can synthesize delphinidin-3-O-hexoside, cyanidin-3-O-hexoside, and peonidin-3-O-hexoside. Here, we research of the fatty acid, VLCFA, and anthocyanin biosynthesis dynamics in the subcultivation, as well as the influence of methyl jasmonate (MeJa) on these processes in the dark- and under-light-grown cell cultures. In the darkness, the formation of VLCFAs is more intense, and the biosynthesis of anthocyanins is significantly activated in the light. MeJA substantially enhances the biosynthesis of anthocyanins in the light and, surprisingly, the formation of VLCFAs in the darknss. In connection with the commonality of the cytosolic pool of malonyl-CoA, which is necessary both for the biosynthesis of VLCFAs and dihydroflavonols (and, ultimately, anthocyanins), the competition of these biosynthetic pathways is discussed.