title: Overexpression ofCaAPXInduces Orchestrated Reactive Oxygen Scavenging and Enhances Cold and Heat Tolerances in Tobacco.
abstract: Ascorbate peroxidase (APX) acts indispensably in synthesizing L-ascorbate (AsA) which is pivotal to plant stress tolerance by detoxifying reactive oxygen species (ROS). Enhanced activity of APX has been shown to be a key step for genetic engineering of improving plant tolerance. However it needs a deeper understanding on the maintenance of cellular ROS homeostasis in response to stress. In this study, we identified and characterized anAPX(CaAPX) gene fromCamellia azalea. Quantitative real-time PCR (qRT-PCR) analysis showed thatCaAPXwas expressed in all tissues and peaked in immature green fruits; the expression levels were significantly upregulated upon cold and hot stresses. Transgenic plants displayed marked enhancements of tolerance under both cold and heat treatments, and plant growth was correlated withCaAPXexpression levels. Furthermore, we monitored the activities of several ROS-scavenging enzymes includingCu/Zn-SOD,CAT,DHAR, andMDHAR, and we showed that stress tolerance was synchronized with elevated activities of ROS-scavenging. Moreover, gene expression analysis of ROS-scavenging enzymes revealed a role ofCaAPXto orchestrate ROS signaling in response to temperature stresses. Overall, this study presents a comprehensive characterization of cellular response related toCaAPXexpression and provides insights to breed crops with high temperature tolerances.
authors.affiliation: Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Zhejiang Provincial Key Laboratory of Tree Breeding, Hangzhou, Zhejiang 311400, China; Lianyungang Academy of Agricultural Sciences, Flower Research Center, Lianyungang, Jiangsu 222000, China.
authors.forename: Jiangying
authors.initials: J
authors.lastname: Wang
authors.affiliation: Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Zhejiang Provincial Key Laboratory of Tree Breeding, Hangzhou, Zhejiang 311400, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.affiliation: Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Zhejiang Provincial Key Laboratory of Tree Breeding, Hangzhou, Zhejiang 311400, China.
authors.forename: Hengfu
authors.identifier: 0000-0002-0720-5311
authors.initials: H
authors.lastname: Yin
authors.affiliation: Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Zhejiang Provincial Key Laboratory of Tree Breeding, Hangzhou, Zhejiang 311400, China.
authors.forename: Zhengqi
authors.initials: Z
authors.lastname: Fan
authors.affiliation: Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Zhejiang Provincial Key Laboratory of Tree Breeding, Hangzhou, Zhejiang 311400, China.
authors.forename: Xinlei
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, China.
authors.forename: Sui
authors.initials: S
authors.lastname: Ni
authors.affiliation: Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Zhejiang Provincial Key Laboratory of Tree Breeding, Hangzhou, Zhejiang 311400, China; College of Horticulture and Landscape Architecture, Hunan Agricultural University, Changsha, Hunan 410128, China.
authors.forename: Libo
authors.identifier: 0000-0003-1478-7628
authors.initials: L
authors.lastname: He
authors.affiliation: Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Zhejiang Provincial Key Laboratory of Tree Breeding, Hangzhou, Zhejiang 311400, China.
authors.forename: Jiyuan
authors.identifier: 0000-0002-8865-3772
authors.initials: J
authors.lastname: Li
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D060387:Ascorbate Peroxidases / Q000096:biosynthesis / Q000235:genetics*; D028244:Camellia / Q000201:enzymology / Q000235:genetics; D002374:Catalase / Q000096:biosynthesis; D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant; D005982:Glutathione Transferase / Q000096:biosynthesis; D009247:NADH, NADPH Oxidoreductases / Q000096:biosynthesis; D010100:Oxygen / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics*; D000072105:Superoxide Dismutase-1 / Q000096:biosynthesis; D000071436:Thermotolerance / Q000235:genetics; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development*
chemical_list: D017382:Reactive Oxygen Species; D060387:Ascorbate Peroxidases; D002374:Catalase; D000072105:Superoxide Dismutase-1; D009247:NADH, NADPH Oxidoreductases; C023927:monodehydroascorbate reductase (NADH); D005982:Glutathione Transferase; D010100:Oxygen