title: Differential contribution of individual dehydrin genes from Physcomitrella patens to salt and osmotic stress tolerance.
abstract: The moss Physcomitrella patens can withstand extreme environmental conditions including drought and salt stress. Tolerance to dehydration in mosses is thought to rely on efficient limitation of stress-induced cell damage and repair of cell injury upon stress relief. Dehydrin proteins (DHNs) are part of a conserved cell protecting mechanism in plants although their role in stress tolerance is not well understood. Four DHNs and two DHN-like proteins were identified in the predicted proteome of P. patens. Expression of PpDHNA and PpDHNB was induced by salt and osmotic stress and controlled by abscisic acid. Subcellular localization of the encoded proteins suggested that these dehydrins are localized in cytosol and accumulate near membranes during stress. Comparative analysis of dhnA and dhnB targeted knockout mutants of P. patens revealed that both genes play a role in cellular protection during salt and osmotic stress, although PpDHNA has a higher contribution to stress tolerance. Overexpression of PpDHNA and PpDHNB genes in transgenic Arabidopsis improved rosette and root growth in stress conditions, although PpDHNA was more efficient in this role. These results suggest that specific DHNs contribute considerably to the high stress tolerance of mosses and offer novel tools for genetic engineering stress tolerance of higher plants.
authors.affiliation: Laboratorio de Biología Molecular Vegetal, Facultad de Ciencias, Universidad de la República, Iguá 4225, CP 11400 Montevideo, Uruguay. cruibal@fcien.edu.iy
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ruibal
authors.forename: Imma Pérez
authors.initials: IP
authors.lastname: Salamó
authors.forename: Valentina
authors.initials: V
authors.lastname: Carballo
authors.forename: Alexandra
authors.initials: A
authors.lastname: Castro
authors.forename: Marcel
authors.initials: M
authors.lastname: Bentancor
authors.forename: Omar
authors.initials: O
authors.lastname: Borsani
authors.forename: László
authors.initials: L
authors.lastname: Szabados
authors.forename: Sabina
authors.initials: S
authors.lastname: Vidal
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics*; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D019068:Bryopsida / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055786:Gene Knockout Techniques; D017343:Genes, Plant / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D009995:Osmosis / Q000187:drug effects / Q000502:physiology*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015203:Reproducibility of Results; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C070556:dehydrin proteins, plant; D012965:Sodium Chloride