Metabolic architecture of developing seeds
Our idea is that in vivo metabolic fluxes are locally regulated and connected to seed architecture. In cereal grains, the isolation of the filial from the maternal tissues creates a complex metabolic system, involving a tripartite interaction between the pericarp, endosperm, and embryo. These three grain components in effect form an interactive system of autonomous organs, each following their own genetic programs. To specify whole-grain metabolism at the level of its component tissue parts, we are applying spatially resolved molecular, biochemical and physiological analysis of metabolic activities as well as metabolic modelling approaches.
Recent findings quantified the in vivo metabolic contributions of distinct seed organs and suggest the presence of a mechanism(s) able to ensure metabolic homeostasis in the face of short-term environmental fluctuation (Rolletschek et al., Plant Physiology 2015).
In oilseed rapeseed (Brassica napus), noninvasive NMR-based imaging has previously demonstrated the establishment of steep gradients in lipid accumulation (Borisjuk et al., Progress Lipid Research 2013). We have been investigating how metabolism in the distinct seed organs of B. napus (seed coat, endosperm, inner and outer cotyledons, radicle) is adjusted to local conditions inside the seed (Borisjuk et al, Plant Cell 2013, Lorenz et al., J Proteomics 2014, Schwender et al., Plant Physiology 2015). In current research, we focus on the characterization of the transient endosperm compartment, and investigate how it contributes to growth control of embryo.