title: Physiological and molecular responses to heavy metal stresses suggest different detoxification mechanism of Populus deltoides and P. x canadensis.
abstract: Plants have divergent defense mechanisms against the harmful effects of heavy metals present in excess in soils and groundwaters. Poplars (Populus spp.) are widely cultivated because of their rapid growth and high biomass production, and members of the genus are increasingly used as experimental model organisms of trees and for phytoremediation purposes. Our aim was to investigate the copper and zinc stress responses of three outstanding biomass producer bred poplar lines to identify such transcripts of genes involved in the detoxification mechanisms, which can play an important role in the protection against heavy metals. Poplar cuttings were grown hydroponically and subjected to short-term (one week) mild and sublethal copper and zinc stresses. We evaluated the effects of the applied heavy metals and the responses of plants by detecting the changes of multiple physiological and biochemical parameters. The most severe cellular oxidative damage was caused by 30μM copper treatment, while zinc was less harmful. Analysis of stress-related transcripts revealed genotype-specific differences that are likely related to alterations in heavy metal tolerance. P. deltoides clones B-229 and PE 19/66 clones were clearly more effective at inducing the expression of various genes implicated in the detoxification process, such as the glutathione transferases, metallothioneins, ABC transporters, (namely PtGSTU51, PxMT1, PdABCC2,3), while the P. canadensis line M-1 accumulated more metal, resulting in greater cellular oxidative damage. Our results show that all three poplar clones are efficient in stress acclimatization, but with different molecular bases.
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary. Electronic address: benyo.daniel@gmail.com.
authors.forename: Dániel
authors.initials: D
authors.lastname: Benyó
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Edit
authors.initials: E
authors.lastname: Horváth
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Edit
authors.initials: E
authors.lastname: Németh
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Tünde
authors.initials: T
authors.lastname: Leviczky
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Kinga
authors.initials: K
authors.lastname: Takács
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Nóra
authors.initials: N
authors.lastname: Lehotai
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Feigl
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kolbert
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Ördög
authors.affiliation: Department of Ecology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Róbert
authors.initials: R
authors.lastname: Gallé
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Jolán
authors.initials: J
authors.lastname: Csiszár
authors.affiliation: Laboratory of Arabidopsis Molecular Genetics, Biological Research Centre, Temesvári körút 62, H-6726 Szeged, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Szabados
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Erdei
authors.affiliation: Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Gallé
mesh_terms: D000704:Analysis of Variance; D001673:Biodegradation, Environmental / Q000187:drug effects; D002999:Clone Cells; D003300:Copper / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D008658:Inactivation, Metabolic / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D019216:Metals, Heavy / Q000633:toxicity*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D032107:Populus / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D026361:Reactive Nitrogen Species / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics; D014867:Water / Q000378:metabolism; D015032:Zinc / Q000378:metabolism
chemical_list: D019216:Metals, Heavy; D012333:RNA, Messenger; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D014867:Water; D008315:Malondialdehyde; D003300:Copper; D015032:Zinc
keywords: ABC transporter; Detoxification; Glutathione transferase; Metal stress; Metallothionein; Poplar