title: UV-B mediated metabolic rearrangements in poplar revealed by non-targeted metabolomics.
abstract: Plants have to cope with various abiotic stresses including UV-B radiation (280-315 nm). UV-B radiation is perceived by a photoreceptor, triggers morphological responses and primes plant defence mechanisms such as antioxidant levels, photoreapir or accumulation of UV-B screening pigments. As poplar is an important model system for trees, we elucidated the influence of UV-B on overall metabolite patterns in poplar leaves grown under high UV-B radiation. Combining non-targeted metabolomics with gas exchange analysis and confocal microscopy, we aimed understanding how UV-B radiation triggers metabolome-wide changes, affects isoprene emission, photosynthetic performance, epidermal light attenuation and finally how isoprene-free poplars adjust their metabolome under UV-B radiation. Exposure to UV-B radiation caused a comprehensive rearrangement of the leaf metabolome. Several hundreds of metabolites were up- and down-regulated over various pathways. Our analysis, revealed the up-regulation of flavonoids, anthocyanins and polyphenols and the down-regulation of phenolic precursors in the first 36 h of UV-B treatment. We also observed a down-regulation of steroids after 12 h. The accumulation of phenolic compounds leads to a reduced light transmission in UV-B-exposed plants. However, the accumulation of phenolic compounds was reduced in non-isoprene-emitting plants suggesting a metabolic- or signalling-based interaction between isoprenoid and phenolic pathways.
authors.affiliation: Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, D-85764, Neuherberg, Germany; Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, D-85764, Neuherberg, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Kaling
authors.forename: Basem
authors.initials: B
authors.lastname: Kanawati
authors.forename: Andrea
authors.initials: A
authors.lastname: Ghirardo
authors.forename: Andreas
authors.initials: A
authors.lastname: Albert
authors.forename: Jana Barbro
authors.initials: JB
authors.lastname: Winkler
authors.forename: Werner
authors.initials: W
authors.lastname: Heller
authors.forename: Csengele
authors.initials: C
authors.lastname: Barta
authors.forename: Francesco
authors.initials: F
authors.lastname: Loreto
authors.forename: Philippe
authors.initials: P
authors.lastname: Schmitt-Kopplin
authors.forename: Jörg-Peter
authors.initials: JP
authors.lastname: Schnitzler
mesh_terms: D002070:Butadienes; D045782:Hemiterpenes / Q000378:metabolism*; D055442:Metabolome; D055432:Metabolomics; D018613:Microscopy, Confocal; D010420:Pentanes; D010636:Phenols / Q000378:metabolism; D010788:Photosynthesis / Q000528:radiation effects*; D032107:Populus / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*
chemical_list: D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; D010636:Phenols; C005059:isoprene
keywords: Fourier transform ion cyclotron resonance mass spectrometry; Populus × canescens