title: Changes in polyphenol and sugar concentrations in wild type and genetically modified Nicotiana langsdorffii Weinmann in response to water and heat stress.
abstract: In this study wild type Nicotiana langsdorffii plants were genetically transformed by the insertion of the rat gene (gr) encoding the glucocorticoid receptor or the rolC gene and exposed to water and heat stress. Water stress was induced for 15 days by adding 20% PEG 6000 in the growth medium, whereas the heat treatment was performed at 50 °C for 2 h, after that a re-growing capability study was carried out. The plant response to stress was investigated by determining electrolyte leakage, dry weight biomass production and water content. These data were evaluated in relation to antiradical activity and concentrations of total polyphenols, selected phenolic compounds and some soluble sugars, as biochemical indicators of metabolic changes due to gene insertion and/or stress treatments. As regards the water stress, the measured physiological parameters evidenced an increasing stress level in the order rolC < gr < WT plants (e.g. about 100% and 50% electrolyte leakage increase in WT and gr samples, respectively) and complied with the biochemical pattern, which consisted in a general decrease of antiradical activity and phenolics, together with an increase in sugars. As regard heat stress, electrolyte leakage data were only in partial agreement with the re-growing capability study. In fact, according to this latter evaluation, gr was the genotype less affected by the heat shock. In this regard, sugars and especially phenolic compounds are informative of the long-term effects due to heat shock treatment.
authors.affiliation: Department of Chemistry, University of Florence, Via della Lastruccia, 3 - 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Ancillotti
authors.affiliation: Department of Biology, University of Florence, Via Madonna del Piano, 6 - 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Bogani
authors.affiliation: Department of Agri-Food and Environmental Science, Viale delle Idee, 30 - 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Biricolti
authors.affiliation: Department of Agri-Food and Environmental Science, Viale delle Idee, 30 - 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Calistri
authors.affiliation: Department of Chemistry, University of Florence, Via della Lastruccia, 3 - 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Checchini
authors.affiliation: Department of Chemistry, University of Florence, Via della Lastruccia, 3 - 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Ciofi
authors.affiliation: Department of Biology, University of Florence, Via Madonna del Piano, 6 - 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gonnelli
authors.affiliation: Department of Chemistry, University of Florence, Via della Lastruccia, 3 - 50019 Sesto Fiorentino, Florence, Italy. Electronic address: delbubba@unifi.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Del Bubba
mesh_terms: D050260:Carbohydrate Metabolism; D003681:Dehydration; D018506:Gene Expression Regulation, Plant; D018869:Heat-Shock Response; D006358:Hot Temperature; D010636:Phenols / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D059808:Polyphenols / Q000378:metabolism*; D013312:Stress, Physiological; D014026:Nicotiana / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D019076:Transgenes; D014867:Water / Q000502:physiology*
chemical_list: D010636:Phenols; D059808:Polyphenols; D014867:Water
keywords: Carbohydrates; Glucocorticoid receptor; Heat stress; Phenolics; Transgenic plants; Water stress; rolC