Although the flows of material through metabolic networks are central to cell function, they are not easy to measure other than at the level of inputs and outputs. This is particularly true in plant cells, where the network spans multiple subcellular compartments and where the network may function either heterotrophically or photoautotrophically. Recently, it has become possible to map the fluxes in central carbon metabolism using the stable isotope labelling techniques of metabolic flux analysis (MFA), and to predict intracellular fluxes using constraints-based modelling procedures such as flux balance analysis (FBA).
In this review from Nicholas Kruger and R. George Ratcliffe at the Department of Plant Sciences, University of Oxford, the principal features of MFA and FBA as applied to plants are outlined, followed by a discussion of the insights that have been gained into plant metabolic networks through the application of these time-consuming and non-trivial methods.
Protein ID (intrinsic disorder) plays a significant, yet relatively unexplored role in transcription factors (TFs). In this recent study from Charlotte O'Shea and Karen Skriver in Copenhagen show that analysis of the transcription regulatory domains (TRDs) of six phylogenetically representative, plant-specific NAC [no apical meristem, ATAF (Arabidopsis transcription activation factor), cup-shaped cotyledon] TFs are mostly disordered. The single molecular recognition feature (MoRF) in ANAC046 (Arabidopsis NAC domain containing protein 46) is a functional hot spot mediating interactions with RCD1 (radical-induced cell death 1), a stress-associated hub which exploits disorder and different mechanisms for interactions.