title: Superoxide dismutase and ascorbate peroxidase improve the recovery of photosynthesis in sugarcane plants subjected to water deficit and low substrate temperature.
abstract: The physiological responses of C4 species to simultaneous water deficit and low substrate temperature are poorly understood, as well as the recovery capacity. This study investigated whether the effect of these abiotic stressors is cultivar-dependent. The differential responses of drought-resistant (IACSP94-2094) and drought-sensitive (IACSP97-7065) sugarcane cultivars were characterized to assess the relationship between photosynthesis and antioxidant protection by APX and SOD isoforms under stress conditions. Our results show that drought alone or combined with low root temperature led to excessive energetic pressure at the PSII level. Heat dissipation was increased in both genotypes, but the high antioxidant capacity due to higher SOD and APX activities was genotype-dependent and it operated better in the drought-resistant genotype. High SOD and APX activities were associated with a rapid recovery of photosynthesis in IACSP94-2094 plants after drought and low substrate temperature alone or simultaneously.
authors.affiliation: Laboratório de Fisiologia Vegetal "Coaracy M. Franco", Instituto Agronômico, CP 28, CEP 13012-970 Campinas, SP, Brazil.
authors.forename: Cristina R G
authors.initials: CR
authors.lastname: Sales
authors.forename: Rafael V
authors.initials: RV
authors.lastname: Ribeiro
authors.forename: Joaquim A G
authors.initials: JA
authors.lastname: Silveira
authors.forename: Eduardo C
authors.initials: EC
authors.lastname: Machado
authors.forename: Marcio O
authors.initials: MO
authors.lastname: Martins
authors.forename: Ana Maria M A
authors.initials: AM
authors.lastname: Lagôa
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000975:Antioxidants / Q000378:metabolism; D060387:Ascorbate Peroxidases / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D055864:Droughts; D005838:Genotype; D010641:Phenotype; D010788:Photosynthesis / Q000235:genetics*; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018526:Plant Transpiration; D031786:Saccharum / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics; D013482:Superoxide Dismutase / Q000235:genetics* / Q000378:metabolism; D014867:Water
chemical_list: D000975:Antioxidants; D045332:Photosystem II Protein Complex; D014867:Water; D060387:Ascorbate Peroxidases; D013482:Superoxide Dismutase
keywords: APX; C; CAT; CD; Cold; D; E; ETR; ETR/P(N); EXC; F(V)/F(M); H(2)O(2); NPQ; Oxidative stress; P(N); PET; PPFD; PSII; Photochemical activity; Photosynthesis; R; RDM; ROS; SDM; SOD; Saccharum spp.; TBARS; TDM; Water deficit; actual quantum yield of PSII; apparent electron transport rate; ascorbate-peroxidase; catalase; cold treatment; cold + drought treatment; dag; days after germination; drought treatment; g(s); hydrogen peroxide; leaf CO(2) assimilation; leaf water potential; maximum quantum yield of PSII; non-photochemical quenching; photosynthetic electron transport; photosynthetic photon flux density; photosystem II; ratio between the apparent electron transport rate and leaf CO(2) assimilation; reactive oxygen species; reference treatment; relative excessive photosynthetic photon flux density; root dry matter; shoot dry matter; stomatal conductance; superoxide dismutase; thiobarbituric acid-reactive substances; total dry matter; transpiration; ΔF/F(M)′; Ψ(w)