title: Multiple heat priming enhances thermo-tolerance to a later high temperature stress via improving subcellular antioxidant activities in wheat seedlings.
abstract: Seedlings of winter wheat (Triticum aestivum L.) were firstly twice heat-primed at 32/24 °C, and subsequently subjected to a more severe high temperature stress at 35/27 °C. The later high temperature stress significantly decreased plant biomass and leaf total soluble sugars concentration. However, plants experienced priming (PH) up-regulated the Rubisco activase B encoding gene RcaB, which was in accordance with the higher photosynthesis rate in relation to the non-primed plants (NH) under the later high temperature stress. In relation to NH, the major chlorophyll a/b-binding protein gene Cab was down-regulated in PH plants, implying a reduction of the light absorption to protect the photosystem II from excitation energy under high temperature stress. At the same time, under the later high temperature stress PH plants showed significantly higher actual photochemical efficiency, indicating an improvement of light use efficiency due to the priming pre-treatment. Under the later high temperature stress, PH could be maintained a better redox homeostasis than NH, as exemplified by the higher activities of superoxide dismutase (SOD) in chloroplasts and glutathione reductase (GR), and of peroxidase (POD) in mitochondria, which contributed to the lower superoxide radical production rate and malondialdehyde concentration in both chloroplasts and mitochondria. The improved antioxidant capacity in chloroplasts and mitochondria was related to the up-regulated expressions of Cu/Zn-SOD, Mn-SOD and GR in PH. Collectively, heat priming effectively improved thermo-tolerance of wheat seedlings subjected to a later high temperature stress, which could be largely ascribed to the enhanced anti-oxidation at the subcellular level.
authors.affiliation: National Engineering and Technology Center for Information Agriculture, Key Laboratory of Crop Physiology and Ecology in Southern China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China; Aarhus University, Faculty of Science and Technology, Institute of Agroecology, Research Centre Flakkebjerg, DK 4200 Slagelse, Denmark.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Engineering and Technology Center for Information Agriculture, Key Laboratory of Crop Physiology and Ecology in Southern China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Cai
authors.affiliation: University of Copenhagen, Faculty of Sciences, Department of Plant and Environmental Sciences, Højbakkegaard Allé 13, DK-2630 Taastrup, Denmark.
authors.forename: Fulai
authors.initials: F
authors.lastname: Liu
authors.affiliation: National Engineering and Technology Center for Information Agriculture, Key Laboratory of Crop Physiology and Ecology in Southern China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Tingbo
authors.initials: T
authors.lastname: Dai
authors.affiliation: National Engineering and Technology Center for Information Agriculture, Key Laboratory of Crop Physiology and Ecology in Southern China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Weixing
authors.initials: W
authors.lastname: Cao
authors.affiliation: Aarhus University, Faculty of Science and Technology, Institute of Agroecology, Research Centre Flakkebjerg, DK 4200 Slagelse, Denmark.
authors.forename: Bernd
authors.initials: B
authors.lastname: Wollenweber
authors.affiliation: National Engineering and Technology Center for Information Agriculture, Key Laboratory of Crop Physiology and Ecology in Southern China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: jiangd@njau.edu.cn.
authors.forename: Dong
authors.initials: D
authors.lastname: Jiang
mesh_terms: D000222:Adaptation, Physiological; D000975:Antioxidants / Q000378:metabolism*; D018533:Biomass; D006358:Hot Temperature; D008315:Malondialdehyde / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology*; D013347:Subcellular Fractions / Q000378:metabolism*; D014908:Triticum / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*
chemical_list: D000975:Antioxidants; D008315:Malondialdehyde; D010100:Oxygen
keywords: Antioxidant system; Chloroplasts; GR; H(2)O(2); Heat priming; High temperature tolerance; MDA; MII; Mitochondria; POD; Pn; ROS; RuBP; SOD; TSS; Winter wheat (Triticum aestivum L.); actual photochemical efficiency; g(s); glutathione reductase (EC 1.6.4.2); hydrogen peroxide; malondialdehyde; membrane injury index; peroxidase (EC 1.11.1.7); photosynthetic rate; reactive oxygen species; ribulose-1,5-bisphosphate; stomatal conductance; superoxide dismutase (EC 1.15.1.1); superoxide radical; the quantum yield of quenching due to light-induced processes; total soluble sugars; ΦNPQ; ΦPSII