Parallel determination of enzyme activities and in vivo fluxes in Brassica napus embryos grown on organic or inorganic nitrogen source

Brassica napus embryos were grown in culture with either glutamine and alanine or ammonium nitrate as the sole nitrogen source. Dependent on the nitrogen source, in vivo metabolic fluxes around the TCA cycle changed distinctly. The changes observed in enzyme activity were not consistent with the changes in metabolic flux. It is suggested that the observed flux adjustments are driven by mass balances rather than transcriptional regulation.