title: Cadmium stress antioxidant responses and root-to-shoot communication in grafted tomato plants.
abstract: Many aspects related to ROS modulation of signaling networks and biological processes that control stress responses still remain unanswered. For this purpose, the grafting technique may be a powerful tool to investigate stress signaling and specific responses between plant organs during stress. In order to gain new insights on the modulation of antioxidant stress responses mechanisms, gas-exchange measurements, lipid peroxidation, H2O2 content, proline, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), ascorbate peroxidase (APX) and guaiacol peroxidase (GPOX) were analyzed in Micro-Tom grafted plants submitted to cadmium (Cd). The results observed revealed that higher amounts of Cd accumulated mainly in the roots and rootstocks when compared to leaves and scions. Macronutrients uptake (Ca, S, P and Mg) decreased in non-grafted plants, but differed among plant parts in all grafted plants. The results showed that the accumulation of proline observed in scions of grafted plants could be associated to the lower MDA contents in the scions of grafted plants. In the presence of Cd, non-grafted plants displayed increased CAT, GR, GPOX and APX activities for both tissues, whilst grafted plants revealed distinct trends that clearly indicate signaling responses from the rootstocks, allowing sufficient time to activate defense mechanisms in shoot. The information available concerning plants subjected to grafting can provide a better understanding of the mechanisms of Cd detoxification involving root-to-shoot signaling, opening new possibilities on strategies which can be used to manipulate heavy metal tolerance, since antioxidant systems are directly involved in such mechanism.
authors.affiliation: Depto. de Biologia Aplicada à Agropecuária (DBAA), UNESP - Univ. Estadual Paulista, Jaboticabal, SP, 14884-900, Brazil.
authors.forename: Priscila Lupino
authors.initials: PL
authors.lastname: Gratão
authors.affiliation: Depto. de Biologia Aplicada à Agropecuária (DBAA), UNESP - Univ. Estadual Paulista, Jaboticabal, SP, 14884-900, Brazil.
authors.forename: Carolina Cristina
authors.initials: CC
authors.lastname: Monteiro
authors.affiliation: Centro Universitário da Fundação de Ensino Octávio Bastos, Unifeob, São João da Boa Vista, SP, 13874-149, Brazil.
authors.forename: Tiago
authors.initials: T
authors.lastname: Tezotto
authors.affiliation: Depto. de Biologia Aplicada à Agropecuária (DBAA), UNESP - Univ. Estadual Paulista, Jaboticabal, SP, 14884-900, Brazil.
authors.forename: Rogério Falleiros
authors.initials: RF
authors.lastname: Carvalho
authors.affiliation: Depto. de Biologia Aplicada à Agropecuária (DBAA), UNESP - Univ. Estadual Paulista, Jaboticabal, SP, 14884-900, Brazil.
authors.forename: Letícia Rodrigues
authors.initials: LR
authors.lastname: Alves
authors.affiliation: Depto. de Genética, Escola Superior de Agricultura Luiz de Queiroz-ESALQ, Universidade de São Paulo-USP, Piracicaba, SP, 13418-900, Brazil.
authors.forename: Leila Priscila
authors.initials: LP
authors.lastname: Peters
authors.affiliation: Depto. de Genética, Escola Superior de Agricultura Luiz de Queiroz-ESALQ, Universidade de São Paulo-USP, Piracicaba, SP, 13418-900, Brazil. raa@usp.br.
authors.forename: Ricardo Antunes
authors.initials: RA
authors.lastname: Azevedo
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D050216:Metabolic Detoxication, Phase I / Q000235:genetics; D018384:Oxidative Stress / Q000187:drug effects*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002104:Cadmium; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase
keywords: Cadmium; Grafting; Micro-Tom; Oxidative stress; Signaling