Chang-Qing Ding1, Sophia Ng2,3, Lu Wang1, Yu-Chun Wang1, Na-Na Li1, Xin-Yuan Hao1, Jian-Ming Zeng1, Xin-Chao Wang4, Ya-Jun Yang5. 1. Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China. 2. ARC Centre of Excellence Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia. 3. Institut de Biosciences et Biotechnologies, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Cadarache, 13108, St Paul-Lez-Durance, France. 4. Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China. xcw75@tricaas.com. 5. Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China. yjyang@tricaas.com.
Abstract
MAIN CONCLUSION: Four typical ALTERNATIVE OXIDASE genes have been identified in tea plants, and their sequence features and gene expression profiles have provided useful information for further studies on function and regulation. Alternative oxidase (AOX) is a terminal oxidase located in the respiratory electron transport chain. AOX catalyzes the oxidation of quinol and the reduction of oxygen into water. In this study, a genome-wide search and subsequent DNA cloning were performed to identify and characterize AOX genes in tea plant (Camellia sinensis (L.) O. Kuntze cv. Longjing43). Our results showed that tea plant possesses four AOX genes, i.e., CsAOX1a, CsAOX1d, CsAOX2a and CsAOX2b. Gene structure and protein sequence analyses revealed that all CsAOXs share a four-exon/three-intron structure with highly conserved regions and amino acid residues, which are necessary for AOX secondary structures, catalytic activities and post-translational regulations. All CsAOX were shown to localize in mitochondria using the green fluorescent protein (GFP)-targeting assay. Both CsAOX1a and CsAOX1d were induced by cold, salt and drought stresses, and with different expression patterns in young and mature leaves. Reactive oxygen species (ROS) accumulated strongly after 72 and 96 h cold treatments in both young and mature leaves, while the polyphenol and total catechin decreased significantly only in mature leaves. In comparison to AtAOX1a in Arabidopsis thaliana, CsAOX1a lost almost all of the stress-responsive cis-acting regulatory elements in its promoter region (1500 bp upstream), but possesses a flavonoid biosynthesis-related MBSII cis-acting regulatory element. These results suggest a link between CsAOX1a function and the metabolism of some secondary metabolites in tea plant. Our studies provide a basis for the further elucidation of the biological function and regulation of the AOX pathway in tea plants.
MAIN CONCLUSION: Four typical ALTERNATIVE OXIDASE genes have been identified in tea plants, and their sequence features and gene expression profiles have provided useful information for further studies on function and regulation. Alternative oxidase (AOX) is a terminal oxidase located in the respiratory electron transport chain. AOX catalyzes the oxidation of quinol and the reduction of oxygen into water. In this study, a genome-wide search and subsequent DNA cloning were performed to identify and characterize AOX genes in tea plant (Camellia sinensis (L.) O. Kuntze cv. Longjing43). Our results showed that tea plant possesses four AOX genes, i.e., CsAOX1a, CsAOX1d, CsAOX2a and CsAOX2b. Gene structure and protein sequence analyses revealed that all CsAOXs share a four-exon/three-intron structure with highly conserved regions and amino acid residues, which are necessary for AOX secondary structures, catalytic activities and post-translational regulations. All CsAOX were shown to localize in mitochondria using the green fluorescent protein (GFP)-targeting assay. Both CsAOX1a and CsAOX1d were induced by cold, salt and drought stresses, and with different expression patterns in young and mature leaves. Reactive oxygen species (ROS) accumulated strongly after 72 and 96 h cold treatments in both young and mature leaves, while the polyphenol and total catechin decreased significantly only in mature leaves. In comparison to AtAOX1a in Arabidopsis thaliana, CsAOX1a lost almost all of the stress-responsive cis-acting regulatory elements in its promoter region (1500 bp upstream), but possesses a flavonoid biosynthesis-related MBSII cis-acting regulatory element. These results suggest a link between CsAOX1a function and the metabolism of some secondary metabolites in tea plant. Our studies provide a basis for the further elucidation of the biological function and regulation of the AOX pathway in tea plants.
Authors: Sophia Ng; Aneta Ivanova; Owen Duncan; Simon R Law; Olivier Van Aken; Inge De Clercq; Yan Wang; Chris Carrie; Lin Xu; Beata Kmiec; Hayden Walker; Frank Van Breusegem; James Whelan; Estelle Giraud Journal: Plant Cell Date: 2013-09-17 Impact factor: 11.277
Authors: José Hélio Costa; Erika Freitas Mota; Mariana Virginia Cambursano; Martin Alexander Lauxmann; Luciana Maia Nogueira de Oliveira; Maria da Guia Silva Lima; Elena Graciela Orellano; Dirce Fernandes de Melo Journal: J Plant Physiol Date: 2009-12-14 Impact factor: 3.549
Authors: P A N Punyasiri; I S B Abeysinghe; V Kumar; D Treutter; D Duy; C Gosch; S Martens; G Forkmann; T C Fischer Journal: Arch Biochem Biophys Date: 2004-11-01 Impact factor: 4.013