title: Comprehensive Mitochondrial Metabolic Shift during the Critical Node of Seed Ageing in Rice.
abstract: The critical node (CN) in seed aging in rice (Oryza sativa) is the transformation from Phase I (P-I) to Phase II (P-II) of the reverse S-shaped curve (RS-SC). Although mitochondrial dysfunction plays a key role in seed ageing, the metabolic shift in the CN remains poorly understood. Here, we investigated the mitochondrial regulatory mechanisms during the CN of rice seed ageing. We showed that during the CN of seed ageing, the mitochondrial ultrastructure was impaired, causing oxygen consumption to decrease, along with cytochrome c (cyt c) oxidase and malate dehydrogenase (MDH) activity. In addition, the transcript levels for the alternative pathway of the electron transport chain (ETC) were significantly induced, whereas the transcripts of the cytochrome oxidase (COX) pathway were inhibited. These changes were concomitant with the down-regulation of mitochondrial protein levels related to carbon and nitrogen metabolism, ATP synthase (ATPase) complex, tricarboxylic acid cycle (TCA) cycle, mitochondrial oxidative enzymes, and a variety of other proteins. Therefore, while these responses inhibit the production of ATP and its intermediates, signals from mitochondria (such as the decrease of cyt c and accumulation of reactive oxygen species (ROS)) may also induce oxidative damage. These events provide considerable information about the mitochondrial metabolic shifts involved in the progression of seed ageing in the CN.
authors.affiliation: National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Guangkun
authors.initials: G
authors.lastname: Yin
authors.affiliation: Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Whelan
authors.affiliation: National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Shuhua
authors.initials: S
authors.lastname: Wu
authors.affiliation: National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
authors.affiliation: National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.|Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture & Forestry University, Fuzhou, Fujian, 350002, China.
authors.forename: Baoyin
authors.initials: B
authors.lastname: Chen
authors.affiliation: National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Chen
authors.affiliation: National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Jinmei
authors.initials: J
authors.lastname: Zhang
authors.affiliation: National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Juanjuan
authors.initials: J
authors.lastname: He
authors.affiliation: National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Xin
authors.affiliation: National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xinxiong
authors.initials: X
authors.lastname: Lu
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D002952:Citric Acid Cycle / Q000502:physiology; D045304:Cytochromes c / Q000378:metabolism; D015536:Down-Regulation / Q000502:physiology; D003576:Electron Transport Complex IV / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000378:metabolism*
chemical_list: D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; D002244:Carbon; D045304:Cytochromes c; D008291:Malate Dehydrogenase; D003576:Electron Transport Complex IV; D000251:Adenosine Triphosphatases; D009584:Nitrogen