title: Design of substrate label for steady state flux measurements in plant systems using the metabolic network of Brassica napus embryos.
abstract: Steady state metabolic flux analysis using (13)C labeled substrates is of growing importance in plant physiology and metabolic engineering. The quality of the flux estimates in (13)C metabolic flux analysis depend on the: (i) network structure; (ii) flux values; (iii) design of the labeling substrate; and (iv) label measurements performed. Whereas the first two parameters are facts of nature, the latter two are to some extent controlled by the experimenter, yet they have received little attention in most plant studies. Using the metabolic flux map of developing Brassica napus (Rapeseed) embryos, this study explores the value of optimal substrate label designs obtained with different statistical criteria and addresses the applicability of different optimal designs to biological questions. The results demonstrate the value of optimizing the choice of labeled substrates and show that substrate combinations commonly used in bacterial studies can be far from optimal for mapping fluxes in plant systems. The value of performing additional experiments and the inclusion of measurements is also evaluated.
authors.affiliation: Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA. libourel@msu.edu
authors.forename: Igor G L
authors.initials: IG
authors.lastname: Libourel
authors.forename: Jackson P
authors.initials: JP
authors.lastname: Gehan
authors.forename: Yair
authors.initials: Y
authors.lastname: Shachar-Hill
mesh_terms: D029688:Brassica napus / Q000196:embryology* / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes; D007553:Isotope Labeling; D010427:Pentose Phosphate Pathway; D012107:Research Design; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D012639:Seeds / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D002245:Carbon Dioxide; D012273:Ribulose-Bisphosphate Carboxylase