title: Water stress reveals differential antioxidant responses of tolerant and non-tolerant sugarcane genotypes.
abstract: The biochemical responses of the enzymatic antioxidant system of a drought-tolerant cultivar (IACSP 94-2094) and a commercial cultivar in Brazil (IACSP 95-5000) grown under two levels of soil water restriction (70% and 30% Soil Available Water Content) were investigated. IACSP 94-2094 exhibited one additional active superoxide dismutase (Cu/Zn-SOD VI) isoenzyme in comparison to IACSP 95-5000, possibly contributing to the heightened response of IACSP 94-2094 to the induced stress. The total glutathione reductase (GR) activity increased substantially in IACSP 94-2094 under conditions of severe water stress; however, the appearance of a new GR isoenzyme and the disappearance of another isoenzyme were found not to be related to the stress response because the cultivars from both treatment groups (control and water restrictions) exhibited identical changes. Catalase (CAT) activity seems to have a more direct role in H2O2 detoxification under water stress condition and the shift in isoenzymes in the tolerant cultivar might have contributed to this response, which may be dependent upon the location where the excessive H2O2 is being produced under stress. The improved performance of IACSP 94-2094 under drought stress was associated with a more efficient antioxidant system response, particularly under conditions of mild stress.
authors.affiliation: Departamento de Genética, Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz", Avenida Pádua Dias 11, CP 9, 13418-900 Piracicaba, SP, Brazil.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Boaretto
authors.affiliation: Departamento de Genética, Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz", Avenida Pádua Dias 11, CP 9, 13418-900 Piracicaba, SP, Brazil.
authors.forename: Giselle
authors.initials: G
authors.lastname: Carvalho
authors.affiliation: Departamento de Genética, Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz", Avenida Pádua Dias 11, CP 9, 13418-900 Piracicaba, SP, Brazil.
authors.forename: Lucélia
authors.initials: L
authors.lastname: Borgo
authors.affiliation: Centro Cana de Açúcar, Instituto Agronômico de Campinas, CP 206, 14001-970 Ribeirão Preto, SP, Brazil.
authors.forename: Silvana
authors.initials: S
authors.lastname: Creste
authors.affiliation: Centro Cana de Açúcar, Instituto Agronômico de Campinas, CP 206, 14001-970 Ribeirão Preto, SP, Brazil.
authors.forename: Marcos G A
authors.initials: MG
authors.lastname: Landell
authors.affiliation: Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, CP 6109, 13083-970 Campinas, SP, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Mazzafera
authors.affiliation: Departamento de Genética, Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz", Avenida Pádua Dias 11, CP 9, 13418-900 Piracicaba, SP, Brazil. Electronic address: raa@usp.br.
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Azevedo
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D005838:Genotype; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D031786:Saccharum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013312:Stress, Physiological; D014867:Water
chemical_list: D000975:Antioxidants; D014867:Water; D006861:Hydrogen Peroxide; D002374:Catalase; D005980:Glutathione Reductase
keywords: (1)O(2); Abiotic stress; Antioxidant enzymes; AsA; CAT; Drought stress; GPOX; GPX; GR; GSH; GSSG; H(2)O(2); MDA; O(2−); OH(•); PAGE; ROS; RWC; Reactive oxygen species; Relative Water Content; SAWC; SOD; Soil Available Water Content; TBARS; ascorbic acid; catalase; glutathione; glutathione peroxidase; glutathione reductase; guaiacol peroxidase; hydrogen peroxide; hydroxyl radical; malondialdehyde; oxidized glutathione; polyacrylamide gel electrophoresis; reactive oxygen species; singlet oxygen; superoxide dismutase; superoxide radical; thiobarbituric acid reactive substances