Multi-omic analyses unveil contrasting composition and spatial distribution of specialized metabolites in seeds ofCamelina sativaand other Brassicaceae

Abstract

Seeds of Brassicaceae species produce a large diversity of specialized metabolites (SMs) that strongly influence their quality, with beneficial or toxic effects on human and animal nutrition, and provide resistance to biotic or abiotic stresses. While the distribution of these compounds has been described in leaves and roots tissues, very limited information is available about their spatio-temporal accumulation in seeds of model or crop plants.Camelina sativa(camelina) is an oilseed Brassicaceae cultivated for human and animal nutrition, and for industrial uses. While we previously explored in detail SM diversity and plasticity, no information is available about SM distribution and expression of SM-related proteins and genes in camelina seeds. In this study we used untargeted metabolomics (LC-MS/MS), proteomics (DIA) and transcriptomics (RNA-Seq) to analyse synthesis, transport, modifications and degradations of SMs that are accumulated in the different seed tissues (i.e. seed coat, endosperm, and embryo) at 6 developmental and 2 germination stages. Our results showed specific patterns for many SMs, and related proteins or genes, during seed coat and embryo development. We also showed that, differently fromArabidopsis thalianaseeds, the defence and antinutritional glucosinolates compounds were accumulated in both the seed coat and endosperm, and the corresponding degradation products isothiocyanates were present at high level in the embryos of dry seeds, inC. sativa.Characterizing the spatial dynamics of seed SMs will contribute to the development of crops with an optimized distribution of beneficial and toxic metabolites for seeds quality and animal nutrition.