title: Grassland species differentially regulate proline concentrations under future climate conditions: an integrated biochemical and modelling approach.
abstract: Proline (Pro) is a versatile metabolite playing a role in the protection of plants against environmental stresses. To gain a deeper understanding of the regulation of Pro metabolism under predicted future climate conditions, including drought stress, elevated temperature and CO2 , we combined measurements in contrasting grassland species (two grasses and two legumes) at multiple organisational levels, that is, metabolite concentrations, enzyme activities and gene expression. Drought stress (D) activates Pro biosynthesis and represses its catabolism, and elevated temperature (DT) further elevated its content. Elevated CO2 attenuated the DT effect on Pro accumulation. Computational pathway control analysis allowed a mechanistic understanding of the regulatory changes in Pro metabolism. This analysis indicates that the experimentally observed coregulation of multiple enzymes is more effective in modulating Pro concentrations than regulation of a single step. Pyrroline-5-carboxylate synthetase (P5CS) and pyrroline-5-carboxylate reductase (P5CR) play a central role in grasses (Lolium perenne, Poa pratensis), and arginase (ARG), ornithine aminotransferase (OAT) and P5CR play a central role in legumes (Medicago lupulina, Lotus corniculatus). Different strategies in the regulation of Pro concentrations under stress conditions were observed. In grasses the glutamate pathway is activated predominantly, and in the legumes the ornithine pathway, possibly related to differences in N-nutritional status.
authors.affiliation: Laboratory for Molecular Plant Physiology and Biotechnology, Department of Biology, University of Antwerp, B-2020, Antwerp, Belgium.|Department of Botany, Faculty of Science, University of Beni-Sueif, Beni-Sueif, 62511, Egypt.
authors.forename: Hamada
authors.initials: H
authors.lastname: AbdElgawad
authors.affiliation: Laboratory for Molecular Plant Physiology and Biotechnology, Department of Biology, University of Antwerp, B-2020, Antwerp, Belgium.|Department of Mathematics and Computer Science, University of Antwerp, B-2020, Antwerp, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: De Vos
authors.affiliation: Laboratory for Molecular Plant Physiology and Biotechnology, Department of Biology, University of Antwerp, B-2020, Antwerp, Belgium.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Zinta
authors.affiliation: Laboratory for Molecular Plant Physiology and Biotechnology, Department of Biology, University of Antwerp, B-2020, Antwerp, Belgium.|Molecular Parasitology Unit, Department of Medical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Malgorzata A
authors.initials: MA
authors.lastname: Domagalska
authors.affiliation: Laboratory for Molecular Plant Physiology and Biotechnology, Department of Biology, University of Antwerp, B-2020, Antwerp, Belgium.
authors.forename: Gerrit T S
authors.initials: GT
authors.lastname: Beemster
authors.affiliation: Laboratory for Molecular Plant Physiology and Biotechnology, Department of Biology, University of Antwerp, B-2020, Antwerp, Belgium.
authors.forename: Han
authors.initials: H
authors.lastname: Asard
mesh_terms: D002980:Climate; D018698:Glutamic Acid / Q000378:metabolism; D065948:Grassland; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D009010:Monte Carlo Method; D009952:Ornithine / Q000378:metabolism; D011392:Proline / Q000378:metabolism*; D011758:Pyrroles / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D013816:Thermodynamics
chemical_list: D011758:Pyrroles; D012333:RNA, Messenger; C015485:delta-1-pyrroline-5-carboxylate; D018698:Glutamic Acid; D011392:Proline; D009952:Ornithine
keywords: drought; elevated CO2; elevated temperature; grassland species; metabolic control analysis; proline (Pro) metabolism