title: Heat-induced impairments and recovery of photosynthetic machinery in wheat seedlings. Role of light and prooxidant-antioxidant balance.
abstract: The extent of damage caused to the photosynthetic machinery of 10-d-old wheat seedlings by short-term exposure to mild heat, their capacity to recover from it and the possible roles of H2O2, SOD, catalase and ascorbate peroxidase on the recovery process were investigated. Seedlings were subjected to heat treatments at 40/42/44 °C for 20 min in the dark and allowed to grow for 72 h in light of different irradiances (40-800 μE m(-2) s(-1)) at 20 °C for recovery from heat induced damage. Complete or partial recovery of photosynthetic activities was observed in the seedlings treated at 40 °C and 42 °C, but not at 44 °C. Our data suggest that the balance between (pro)oxidant and antioxidant levels poised by heat stress subsequent light is the crucial factor for the extent of recovery from heat induced damage.
authors.affiliation: Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russia.
authors.forename: Vladimir D
authors.initials: VD
authors.lastname: Kreslavski
authors.forename: Valeri Yu
authors.initials: VY
authors.lastname: Lyubimov
authors.forename: Nadezhda I
authors.initials: NI
authors.lastname: Shabnova
authors.forename: Tamara I
authors.initials: TI
authors.lastname: Balakhnina
authors.forename: Anatoli A
authors.initials: AA
authors.lastname: Kosobryukhov
keywords: Antioxidant enzymes; Heat treatment; PSII; Photosynthesis; Wheat (Triticum aeslivum L.)