Adjustment of central metabolism to the hypoxic environment inside the seed
The hypoxic state comes about whenever the capacity for oxygen diffusion is restricted, so that the concentration of oxygen available falls below the level required for cellular metabolism. These conditions apply frequently to the developing seed (for review see Rolletschek H. (2012). “Hypoxia – a phenomenon which shapes seed metabolism”. Habilitation at the Naturwissenschaftliche Fakultät, Leibniz Universität Hannover/Germany). Seed hypoxia is not only because of high respiratory activities but mainly due to the low void space/porosity of seed tissues, and thus limited diffusive oxygen uptake (Verboeven et al., New Phytologist 2013).
In current work, funded by DFG, we are investigating the implications of internal hypoxia for assimilate uptake and partitioning in the developing maize kernel. In particular we work on the functional role of specific metabolic enzymes (PPDK; Lappe et al., PNAS 2018), the metabolic heterogeneity of endosperm (Rolletschek et al., 2017 In: Maize Kernel Development), phytoglobins and signalling components using a number of transgenic and mutant plants.