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Tanimoto H, Umekawa Y, Takahashi H, Goto K, Ito K. Gene expression and metabolite levels converge in the thermogenic spadix of skunk cabbage. Plant Physiol 2024:kiae059. [PMID: 38318875 DOI: 10.1093/plphys/kiae059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 02/07/2024]
Abstract
The inflorescence (spadix) of skunk cabbage (Symplocarpus renifolius) is strongly thermogenic and can regulate its temperature at around 23°C even when the ambient temperature drops below freezing. To elucidate the mechanisms underlying developmentally controlled thermogenesis and thermoregulation in skunk cabbage, we conducted a comprehensive transcriptome and metabolome analysis across three developmental stages of spadix development. Our RNA-seq analysis revealed distinct groups of expressed genes, with selenium-binding protein 1/methanethiol oxidase (SBP1/MTO) exhibiting the highest levels in thermogenic florets. Notably, the expression of alternative oxidase (AOX) was consistently high from the pre-thermogenic stage through the thermogenic stage in the florets. Metabolome analysis showed that alterations in nucleotide levels correspond with the developmentally controlled and tissue-specific thermogenesis of skunk cabbage, evident by a substantial increase in AMP levels in thermogenic florets. Our study also reveals that hydrogen sulfide, a product of SBP1/MTO, inhibits cytochrome c (COX)-mediated mitochondrial respiration while AOX-mediated respiration remains relatively unaffected. Specifically, at lower temperatures, the inhibitory effect of hydrogen sulfide on COX-mediated respiration increases, promoting a shift towards the dominance of AOX-mediated respiration. Finally, despite the differential regulation of genes and metabolites throughout spadix development, we observed a convergence of gene expression and metabolite accumulation patterns during thermogenesis. This synchrony may play a key role in developmentally regulated thermogenesis. Moreover, such convergence during the thermogenic stage in the spadix may provide a solid molecular basis for thermoregulation in skunk cabbage.
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Affiliation(s)
- Haruka Tanimoto
- United Graduate School of Agricultural Science, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan
| | - Yui Umekawa
- Akita Research Institute of Food and Brewing, 4-26 Sanuki, Araya-machi, Akita 010-1623, Japan
| | - Hideyuki Takahashi
- Department of Agriculture, School of Agriculture, Tokai University, Kumamoto 862-8652, Japan
| | - Kota Goto
- Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan
| | - Kikukatsu Ito
- United Graduate School of Agricultural Science, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan
- Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan
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2
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Lagarda-Clark EA, Goulet C, Duarte-Sierra A. Biochemical dynamics during postharvest: Highlighting the interplay of stress during storage and maturation of fresh produce. Biomol Concepts 2024; 15:bmc-2022-0048. [PMID: 38587059 DOI: 10.1515/bmc-2022-0048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 03/18/2024] [Indexed: 04/09/2024] Open
Abstract
The lifecycle of fresh produce involves a sequence of biochemical events during their ontology, and these events are particularly significant for climacteric fruits. A high demand during ripening is observed in these plant products, which is reflected in a high rate of respiration and ethylene production. Increased respiratory demand triggers the activation of secondary pathways such as alternate oxidase, which do not experience critical increases in energy consumption in non-climacteric fruit. In addition, biochemical events produced by external factors lead to compensatory responses in fresh produce to counteract the oxidative stress caused by the former. The dynamics of these responses are accompanied by signaling, where reactive oxygen species play a pivotal role in fresh product cell perception. This review aims to describe the protection mechanisms of fresh produce against environmental challenges and how controlled doses of abiotic stressors can be used to improve quality and prolong their shelf-life through the interaction of stress and defense mechanisms.
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Affiliation(s)
- Ernesto Alonso Lagarda-Clark
- Food Science Department, Laval University, Quebec, QC G1V 0A6, Canada
- Center for Research in Plant Innovation (CRIV), Laval University, Quebec, QC G1V 6 0A6, Canada
- Institute on Nutrition and Functional Foods (INAF), Laval University, Quebec, QC G1V 8 0A6, Canada
| | - Charles Goulet
- Food Science Department, Laval University, Quebec, QC G1V 0A6, Canada
- Center for Research in Plant Innovation (CRIV), Laval University, Quebec, QC G1V 6 0A6, Canada
- Department of Phytology, Université Laval, Québec, QC G1V 0A6, Canada
| | - Arturo Duarte-Sierra
- Food Science Department, Laval University, Quebec, QC G1V 0A6, Canada
- Center for Research in Plant Innovation (CRIV), Laval University, Quebec, QC G1V 6 0A6, Canada
- Institute on Nutrition and Functional Foods (INAF), Laval University, Quebec, QC G1V 8 0A6, Canada
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3
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Flipphi M, Márton A, Bíró V, Ág N, Sándor E, Fekete E, Karaffa L. Generation, Transfer, and Loss of Alternative Oxidase Paralogues in the Aspergillaceae Family. J Fungi (Basel) 2023; 9:1195. [PMID: 38132795 PMCID: PMC10744626 DOI: 10.3390/jof9121195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 12/23/2023] Open
Abstract
Alternative oxidase (Aox) is a terminal oxidase operating in branched electron transport. The activity correlates positively with overflow metabolisms in certain Aspergilli, converting intracellular glucose by the shortest possible path into organic acids, like citrate or itaconate. Aox is nearly ubiquitous in fungi, but aox gene multiplicity is rare. Nevertheless, within the family of the Aspergillaceae and among its various species of industrial relevance-Aspergillus niger, A. oryzae, A. terreus, Penicillium rubens-paralogous aox genes coexist. Paralogous genes generally arise from duplication and are inherited vertically. Here, we provide evidence of four independent duplication events along the lineage that resulted in aox paralogues (aoxB) in contemporary Aspergillus and Penicillium taxa. In some species, three aox genes are co-expressed. The origin of the A. niger paralogue is different than that of the A. terreus paralogue, but all paralogous clades ultimately arise from ubiquitous aoxA parent genes. We found different patterns of uncorrelated gene losses reflected in the Aspergillus pedigree, albeit the original aoxA orthologues persist everywhere and are never replaced. The loss of acquired paralogues co-determines the contemporary aox gene content of individual species. In Aspergillus calidoustus, the two more ancient paralogues have, in effect, been replaced by two aoxB genes of distinct origins.
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Affiliation(s)
- Michel Flipphi
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (M.F.); (A.M.); (V.B.); (N.Á.); (L.K.)
| | - Alexandra Márton
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (M.F.); (A.M.); (V.B.); (N.Á.); (L.K.)
- Juhász-Nagy Pál Doctoral School of Biology and Environmental Sciences, University of Debrecen, H-4032 Debrecen, Hungary
| | - Vivien Bíró
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (M.F.); (A.M.); (V.B.); (N.Á.); (L.K.)
- Juhász-Nagy Pál Doctoral School of Biology and Environmental Sciences, University of Debrecen, H-4032 Debrecen, Hungary
| | - Norbert Ág
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (M.F.); (A.M.); (V.B.); (N.Á.); (L.K.)
| | - Erzsébet Sándor
- Institute of Food Science, Faculty of Agricultural and Food Science and Environmental Management, University of Debrecen, H-4032 Debrecen, Hungary;
| | - Erzsébet Fekete
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (M.F.); (A.M.); (V.B.); (N.Á.); (L.K.)
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (M.F.); (A.M.); (V.B.); (N.Á.); (L.K.)
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Sharma R, Gibb AA, Barnts K, Elrod JW, Puri S. Alternative oxidase promotes high iron tolerance in Candida albicans. Microbiol Spectr 2023; 11:e0215723. [PMID: 37929974 PMCID: PMC10714975 DOI: 10.1128/spectrum.02157-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 10/10/2023] [Indexed: 11/07/2023] Open
Abstract
IMPORTANCE The yeast C. albicans exhibits metabolic flexibility for adaptability to host niches with varying availability of nutrients including essential metals like iron. For example, blood is iron deplete, while the oral cavity and the intestinal lumen are considered iron replete. We show here that C. albicans can tolerate very high levels of environmental iron, despite an increase in high iron-induced reactive oxygen species (ROS) that it mitigates with the help of a unique oxidase, known as alternative oxidase (AOX). High iron induces AOX1/2 that limits mitochondrial accumulation of ROS. Genetic elimination of AOX1/2 resulted in diminished virulence during oropharyngeal candidiasis in high iron mice. Since human mitochondria lack AOX protein, it represents a unique target for treatment of fungal infections.
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Affiliation(s)
- Rishabh Sharma
- Oral Microbiome Research Laboratory, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania, USA
| | - Andrew A. Gibb
- Department of Cardiovascular Sciences, Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Kelcie Barnts
- Oral and Maxillofacial Pathology, Medicine and Surgery, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania, USA
| | - John W. Elrod
- Department of Cardiovascular Sciences, Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Sumant Puri
- Oral Microbiome Research Laboratory, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania, USA
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5
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Gureev AP, Alimova AA, Silachev DN, Plotnikov EY. Noncoupled Mitochondrial Respiration as Therapeutic Approach for the Treatment of Metabolic Diseases: Focus on Transgenic Animal Models. Int J Mol Sci 2023; 24:16491. [PMID: 38003681 PMCID: PMC10671337 DOI: 10.3390/ijms242216491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
Mitochondrial dysfunction contributes to numerous chronic diseases, and mitochondria are targets for various toxins and xenobiotics. Therefore, the development of drugs or therapeutic strategies targeting mitochondria is an important task in modern medicine. It is well known that the primary, although not the sole, function of mitochondria is ATP generation, which is achieved by coupled respiration. However, a high membrane potential can lead to uncontrolled reactive oxygen species (ROS) production and associated dysfunction. For over 50 years, scientists have been studying various synthetic uncouplers, and for more than 30 years, uncoupling proteins that are responsible for uncoupled respiration in mitochondria. Additionally, the proteins of the mitochondrial alternative respiratory pathway exist in plant mitochondria, allowing noncoupled respiration, in which electron flow is not associated with membrane potential formation. Over the past two decades, advances in genetic engineering have facilitated the creation of various cellular and animal models that simulate the effects of uncoupled and noncoupled respiration in different tissues under various disease conditions. In this review, we summarize and discuss the findings obtained from these transgenic models. We focus on the advantages and limitations of transgenic organisms, the observed physiological and biochemical changes, and the therapeutic potential of uncoupled and noncoupled respiration.
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Affiliation(s)
- Artem P. Gureev
- Department of Genetics, Cytology and Bioengineering, Voronezh State University, 394018 Voronezh, Russia; (A.P.G.); (A.A.A.)
- Laboratory of Metagenomics and Food Biotechnology, Voronezh State University of Engineering Technologies, 394036 Voronezh, Russia
| | - Alina A. Alimova
- Department of Genetics, Cytology and Bioengineering, Voronezh State University, 394018 Voronezh, Russia; (A.P.G.); (A.A.A.)
- Laboratory of Metagenomics and Food Biotechnology, Voronezh State University of Engineering Technologies, 394036 Voronezh, Russia
| | - Denis N. Silachev
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia;
| | - Egor Y. Plotnikov
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia;
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6
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Lukeš J, Speijer D, Zíková A, Alfonzo JD, Hashimi H, Field MC. Trypanosomes as a magnifying glass for cell and molecular biology. Trends Parasitol 2023; 39:902-912. [PMID: 37679284 DOI: 10.1016/j.pt.2023.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 09/09/2023]
Abstract
The African trypanosome, Trypanosoma brucei, has developed into a flexible and robust experimental model for molecular and cellular parasitology, allowing us to better combat these and related parasites that cause worldwide suffering. Diminishing case numbers, due to efficient public health efforts, and recent development of new drug treatments have reduced the need for continued study of T. brucei in a disease context. However, we argue that this pathogen has been instrumental in revolutionary discoveries that have widely informed molecular and cellular biology and justifies continuing research as an experimental model. Ongoing work continues to contribute towards greater understanding of both diversified and conserved biological features. We discuss multiple examples where trypanosomes pushed the boundaries of cell biology and hope to inspire researchers to continue exploring these remarkable protists as tools for magnifying the inner workings of cells.
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Affiliation(s)
- Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic.
| | - Dave Speijer
- Medical Biochemistry, University of Amsterdam, AMC, Amsterdam, The Netherlands
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Juan D Alfonzo
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Hassan Hashimi
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Mark C Field
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; School of Life Sciences, University of Dundee, Dundee, UK
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Ji J, Lin S, Xin X, Li Y, He J, Xu X, Zhao Y, Su G, Lu X, Yin G. Effects of OsAOX1a Deficiency on Mitochondrial Metabolism at Critical Node of Seed Viability in Rice. Plants (Basel) 2023; 12:2284. [PMID: 37375909 DOI: 10.3390/plants12122284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/29/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023]
Abstract
Mitochondrial alternative oxidase 1a (AOX1a) plays an extremely important role in the critical node of seed viability during storage. However, the regulatory mechanism is still poorly understood. The aim of this study was to identify the regulatory mechanisms by comparing OsAOX1a-RNAi and wild-type (WT) rice seed during artificial aging treatment. Weight gain and time for the seed germination percentage decreased to 50% (P50) in OsAOX1a-RNAi rice seed, indicating possible impairment in seed development and storability. Compared to WT seeds at 100%, 90%, 80%, and 70% germination, the NADH- and succinate-dependent O2 consumption, the activity of mitochondrial malate dehydrogenase, and ATP contents all decreased in the OsAOX1a-RNAi seeds, indicating that mitochondrial status in the OsAOX1a-RNAi seeds after imbibition was weaker than in the WT seeds. In addition, the reduction in the abundance of Complex I subunits showed that the capacity of the mitochondrial electron transfer chain was significantly inhibited in the OsAOX1a-RNAi seeds at the critical node of seed viability. The results indicate that ATP production was impaired in the OsAOX1a-RNAi seeds during aging. Therefore, we conclude that mitochondrial metabolism and alternative pathways were severely inhibited in the OsAOX1a-RNAi seeds at critical node of viability, which could accelerate the collapse of seed viability. The precise regulatory mechanism of the alternative pathway at the critical node of viability needs to be further analyzed. This finding might provide the basis for developing monitoring and warning indicators when seed viability declines to the critical node during storage.
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Affiliation(s)
- Jing Ji
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Shuangshuang Lin
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Institute of Agricultural Bioresource, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China
| | - Xia Xin
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yang Li
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Juanjuan He
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xinyue Xu
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yunxia Zhao
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Gefei Su
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- College of Biological Science, China Agricultural University, Beijing 100193, China
| | - Xinxiong Lu
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Guangkun Yin
- National Crop Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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Zhong YH, Guo ZJ, Wei MY, Wang JC, Song SW, Chi BJ, Zhang YC, Liu JW, Li J, Zhu XY, Tang HC, Song LY, Xu CQ, Zheng HL. Hydrogen sulfide upregulates the alternative respiratory pathway in mangrove plant Avicennia marina to attenuate waterlogging-induced oxidative stress and mitochondrial damage in a calcium-dependent manner. Plant Cell Environ 2023; 46:1521-1539. [PMID: 36658747 DOI: 10.1111/pce.14546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/11/2023] [Accepted: 01/16/2023] [Indexed: 06/17/2023]
Abstract
Hydrogen sulfide (H2 S) is considered to mediate plant growth and development. However, whether H2 S regulates the adaptation of mangrove plant to intertidal flooding habitats is not well understood. In this study, sodium hydrosulfide (NaHS) was used as an H2 S donor to investigate the effect of H2 S on the responses of mangrove plant Avicennia marina to waterlogging. The results showed that 24-h waterlogging increased reactive oxygen species (ROS) and cell death in roots. Excessive mitochondrial ROS accumulation is highly oxidative and leads to mitochondrial structural and functional damage. However, the application of NaHS counteracted the oxidative damage caused by waterlogging. The mitochondrial ROS production was reduced by H2 S through increasing the expressions of the alternative oxidase genes and increasing the proportion of alternative respiratory pathway in the total mitochondrial respiration. Secondly, H2 S enhanced the capacity of the antioxidant system. Meanwhile, H2 S induced Ca2+ influx and activated the expression of intracellular Ca2+ -sensing-related genes. In addition, the alleviating effect of H2 S on waterlogging can be reversed by Ca2+ chelator and Ca2+ channel blockers. In conclusion, this study provides the first evidence to explain the role of H2 S in waterlogging adaptation in mangrove plants from the mitochondrial aspect.
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Affiliation(s)
- You-Hui Zhong
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Ze-Jun Guo
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Ming-Yue Wei
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
- School of Ecology, Resources and Environment, Dezhou University, Dezhou, Shandong, China
| | - Ji-Cheng Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Shi-Wei Song
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Bing-Jie Chi
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Yu-Chen Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Jing-Wen Liu
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Jing Li
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Xue-Yi Zhu
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Han-Chen Tang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Ling-Yu Song
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Chao-Qun Xu
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Hai-Lei Zheng
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
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Martínez M, González-Aravena M, Held C, Abele D. A molecular perspective on the invasibility of the southern ocean benthos: The impact of hypoxia and temperature on gene expression in South American and Antarctic Aequiyoldia bivalves. Front Physiol 2023; 14:1083240. [PMID: 36895632 PMCID: PMC9989211 DOI: 10.3389/fphys.2023.1083240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 02/10/2023] [Indexed: 02/23/2023] Open
Abstract
When an organism makes a long-distance transition to a new habitat, the associated environmental change is often marked and requires physiological plasticity of larvae, juveniles, or other migrant stages. Exposing shallow-water marine bivalves (Aequiyoldia cf. eightsii) from southern South America (SSA) and the West Antarctic Peninsula (WAP) to changes in temperature and oxygen availability, we investigated changes in gene expression in a simulated colonization experiment of the shores of a new continent after crossing of the Drake Passage, and in a warming scenario in the WAP. Bivalves from SSA were cooled from 7°C (in situ) to 4°C and 2°C (future warmed WAP conditions), WAP bivalves were warmed from 1.5°C (current summer in situ) to 4°C (warmed WAP), gene expression patterns in response to thermal stress by itself and in combination with hypoxia were measured after 10 days. Our results confirm that molecular plasticity may play a vital role for local adaptation. Hypoxia had a greater effect on the transcriptome than temperature alone. The effect was further amplified when hypoxia and temperature acted as combined stressors. The WAP bivalves showed a remarkable ability to cope with short-term exposure to hypoxia by switching to a metabolic rate depression strategy and activating the alternative oxidation pathway, whilst the SSA population showed no comparable response. In SSA, the high prevalence of apoptosis-related differentially expressed genes especially under combined higher temperatures and hypoxia indicated that the SSA Aequiyoldia are operating near their physiological limits already. While the effect of temperature per se may not represent the single most effective barrier to Antarctic colonization by South American bivalves, the current distribution patterns as well as their resilience to future conditions can be better understood by looking at the synergistic effects of temperature in conjunction with short-term exposure to hypoxia.
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Affiliation(s)
- Mariano Martínez
- Funktionelle Ökologie, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
| | | | - Christoph Held
- Funktionelle Ökologie, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
| | - Doris Abele
- Funktionelle Ökologie, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
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10
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Inoue T, Akaji Y, Baba S, Noguchi K. Temperature dependence of O 2 respiration in mangrove leaves and roots: implications for seedling dispersal phenology. New Phytol 2023; 237:100-112. [PMID: 36156265 PMCID: PMC10091777 DOI: 10.1111/nph.18513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 09/10/2022] [Indexed: 06/16/2023]
Abstract
Seasonal differences in diaspore dispersal of three mangrove species, Kandelia obovata, Bruguiera gymnorrhiza and Rhizophora stylosa, suggest that respiratory energy production and demand may differ as a result of interspecific differences in temperature dependence of growth and maintenance processes during seedling establishment. We analyzed growth, temperature dependencies of respiratory O2 consumption and amounts of respiratory chain enzymes in seedlings of these species grown at various temperatures. Respiration rates measured at the low reference temperature, RREF , were highest in leaves of 15°C-grown K. obovata, whose dispersal occurs in the cold season, while root RREF of 15°C-grown R. stylosa was 60% those of the other species, possibly because of warm conditions during its establishment phase. In leaves and roots of K. obovata and leaves of R. stylosa, the overall activation energy, Eo , changed with growth temperature associated with changes in the ratios of the amount of protein in the two respiratory pathways. However, Eo of seedlings of B. gymnorrhiza, which has a long dispersal phase, were constant and independent of growth temperature. The different temperature responses of seedling respiration and growth among these three species may reflect the seasonal temperature range of seedling dispersal and establishment in each species.
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Affiliation(s)
- Tomomi Inoue
- National Institute for Environmental Studies16‐2 Onogawa TsukubaIbaraki305‐8506Japan
| | - Yasuaki Akaji
- National Institute for Environmental Studies16‐2 Onogawa TsukubaIbaraki305‐8506Japan
| | - Shigeyuki Baba
- International Society for Mangrove EcosystemsUniversity of the RyukyusNishiharaOkinawa903‐0129Japan
| | - Ko Noguchi
- School of Life ScienceTokyo University of Pharmacy and Life Sciences1432‐1 Horinouchi HachiojiTokyo192‐0392Japan
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11
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Matos IF, Morales LMM, Santana DB, Silva GMC, Gomes MMDA, Ayub RA, Costa JH, de Oliveira JG. Ascorbate synthesis as an alternative electron source for mitochondrial respiration: Possible implications for the plant performance. Front Plant Sci 2022; 13:987077. [PMID: 36507441 PMCID: PMC9727407 DOI: 10.3389/fpls.2022.987077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/31/2022] [Indexed: 06/01/2023]
Abstract
The molecule vitamin C, in the chemical form of ascorbic acid (AsA), is known to be essential for the metabolism of humans and animals. Humans do not produce AsA, so they depend on plants as a source of vitamin C for their food. The AsA synthesis pathway occurs partially in the cytosol, but the last oxidation step is physically linked to the respiratory chain of plant mitochondria. This oxidation step is catalyzed by l-galactono-1,4-lactone dehydrogenase (l-GalLDH). This enzyme is not considered a limiting step for AsA production; however, it presents a distinguishing characteristic: the l-GalLDH can introduce electrons directly into the respiratory chain through cytochrome c (Cytc) and therefore can be considered an extramitochondrial electron source that bypasses the phosphorylating Complex III. The use of Cytc as electron acceptor has been debated in terms of its need for AsA synthesis, but little has been said in relation to its impact on the functioning of the respiratory chain. This work seeks to offer a new view about the possible changes that result of the link between AsA synthesis and the mitochondrial respiration. We hypothesized that some physiological alterations related to low AsA may be not only explained by the deficiency of this molecule but also by the changes in the respiratory function. We discussed some findings showing that respiratory mutants contained changes in AsA synthesis. Besides, recent works that also indicate that the excessive electron transport via l-GalLDH enzyme may affect other respiratory pathways. We proposed that Cytc reduction by l-GalLDH may be part of an alternative respiratory pathway that is active during AsA synthesis. Also, it is proposed that possible links of this pathway with other pathways of alternative electron transport in plant mitochondria may exist. The review suggests potential implications of this relationship, particularly for situations of stress. We hypothesized that this pathway of alternative electron input would serve as a strategy for adaptation of plant respiration to changing conditions.
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Affiliation(s)
- Isabelle Faria Matos
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
| | | | - Diederson Bortolini Santana
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
| | - Gláucia Michelle Cosme Silva
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
| | - Mara Menezes de Assis Gomes
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
| | - Ricardo Antônio Ayub
- Laboratory of Biotechnology Applied to Fruit Growing, Department of Phytotechny and Phytosanitary, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil
| | - José Hélio Costa
- Functional Genomics and Bioinformatics, Department of Biochemistry and Molecular Biology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
| | - Jurandi Gonçalves de Oliveira
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
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12
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Romero-Aguilar L, Vázquez-Meza H, Guerra-Sánchez G, Luqueño-Bocardo OI, Pardo JP. The Mitochondrial Alternative Oxidase in Ustilago maydis Is Not Involved in Response to Oxidative Stress Induced by Paraquat. J Fungi (Basel) 2022; 8:1221. [PMID: 36422042 PMCID: PMC9693204 DOI: 10.3390/jof8111221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/10/2022] [Accepted: 11/17/2022] [Indexed: 07/29/2023] Open
Abstract
It has been shown that the alternative oxidase in mitochondria of fungi and plants has important functions in the response against stress conditions, although their role in some organisms is still unknown. This is the case of Ustilago maydis. There is no evidence of the participation of the U. maydis Aox1 in stressful conditions such as desiccation, high or low temperature, and low pH, among others. Therefore, in this work, we studied the role of the U. maydis Aox1 in cells exposed to oxidative stress induced by methyl viologen (paraquat). To gain insights into the role of this enzyme, we took advantage of four strains: the FB2 wild-type, a strain without the alternative oxidase (FB2aox1Δ), other with the Aox1 fused to the Gfp under the control of the original promoter (FB2aox1-Gfp), and one expressing constitutively de Aox1-Gfp (FB2Potef:aox1-Gfp). Cells were incubated for various times in the presence of 1 mM paraquat and growth, replicative capacities, mitochondrial respiratory activity, Aox1 capacity, and the activities of several antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase, and superoxide dismutase) were assayed. The results show that (1) the response of U. maydis against oxidative stress was the same in the presence or absence of the Aox1; (2) the activities of the antioxidant enzymes remained constant despite the oxidative stress; and (3) there was a decrease in the GSH/GSSG ratio in U. maydis cells incubated with paraquat.
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Affiliation(s)
- Lucero Romero-Aguilar
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Interior, Ciudad Universitaria, Coyoacán, Ciudad de México C.P. 04510, Mexico
| | - Héctor Vázquez-Meza
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Interior, Ciudad Universitaria, Coyoacán, Ciudad de México C.P. 04510, Mexico
| | - Guadalupe Guerra-Sánchez
- Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Departamento de Microbiología, Plan de Carpio y Plan de Ayala S/N Santo Tomás, Miguel Hidalgo, Ciudad de México C.P. 11340, Mexico
| | - Oscar Ivan Luqueño-Bocardo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Interior, Ciudad Universitaria, Coyoacán, Ciudad de México C.P. 04510, Mexico
| | - Juan Pablo Pardo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Interior, Ciudad Universitaria, Coyoacán, Ciudad de México C.P. 04510, Mexico
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13
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Sweetman C, Waterman CD, Wong DC, Day DA, Jenkins CL, Soole KL. Altering the balance between AOX1A and NDB2 expression affects a common set of transcripts in Arabidopsis. Front Plant Sci 2022; 13:876843. [PMID: 36466234 PMCID: PMC9716356 DOI: 10.3389/fpls.2022.876843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 10/24/2022] [Indexed: 06/17/2023]
Abstract
Stress-responsive components of the mitochondrial alternative electron transport pathway have the capacity to improve tolerance of plants to abiotic stress, particularly the alternative oxidase AOX1A but also external NAD(P)H dehydrogenases such as NDB2, in Arabidopsis. NDB2 and AOX1A can cooperate to entirely circumvent the classical electron transport chain in Arabidopsis mitochondria. Overexpression of AOX1A or NDB2 alone can have slightly negative impacts on plant growth under optimal conditions, while simultaneous overexpression of NDB2 and AOX1A can reverse these phenotypic effects. We have taken a global transcriptomic approach to better understand the molecular shifts that occur due to overexpression of AOX1A alone and with concomitant overexpression of NDB2. Of the transcripts that were significantly up- or down- regulated in the AOX1A overexpression line compared to wild type (410 and 408, respectively), the majority (372 and 337, respectively) reverted to wild type levels in the dual overexpression line. Several mechanisms for the AOX1A overexpression phenotype are proposed based on the functional classification of these 709 genes, which can be used to guide future experiments. Only 28 genes were uniquely up- or down-regulated when NDB2 was overexpressed in the AOX1A overexpression line. On the other hand, many unique genes were deregulated in the NDB2 knockout line. Furthermore, several changes in transcript abundance seen in the NDB2 knockout line were consistent with changes in the AOX1A overexpression line. The results suggest that an imbalance in AOX1A:NDB2 protein levels caused by under- or over-expression of either component, triggers a common set of transcriptional responses that may be important in mitochondrial redox regulation. The most significant changes were transcripts associated with photosynthesis, secondary metabolism and oxidative stress responses.
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Affiliation(s)
- Crystal Sweetman
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
| | | | - Darren C.J. Wong
- College of Science, Australian National University, Canberra, ACT, Australia
| | - David A. Day
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
| | - Colin L.D. Jenkins
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
| | - Kathleen L. Soole
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
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14
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Garmash EV, Dymova OV, Silina EV, Malyshev RV, Belykh ES, Shelyakin MA, Velegzhaninov IO. AOX1a Expression in Arabidopsis thaliana Affects the State of Chloroplast Photoprotective Systems under Moderately High Light Conditions. Plants (Basel) 2022; 11:plants11223030. [PMID: 36432760 PMCID: PMC9697105 DOI: 10.3390/plants11223030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/27/2022] [Accepted: 11/02/2022] [Indexed: 06/01/2023]
Abstract
Alternative oxidase (AOX) in the mitochondrial electron transport chain is considered important for sustaining photosynthesis under high light conditions. Here, we examined the effects of the AOX pathway on the state of chloroplast photoprotective systems. Arabidopsis thaliana plants (4 weeks old), comprising three genotypes (wild type [WT], overexpressing [XX-2] and antisense [AS-12] lines for AOX1a), were exposed to moderately high light conditions (MHL, 400 μmol m-2 s-1) in a short-term experiment (8 h). After 8 h of MHL, the WT and XX-2 plants showed stable non-photochemical quenching (qN) and violaxanthin cycle activity. Antisense plants displayed the lowest level of qN and a lower de-epoxidation state (DEPS) relative to plants of the same line after 4-6 h MHL, as well as compared to WT and XX-2 plants after 8 h MHL. The decline in DEPS in AS-12 plants was attributed to an insufficient violaxanthin de-epoxidase activity, which in turn was associated with a decrease in reduced ascorbate levels in the chloroplasts and leaves. Simultaneously, gene expression and the activity of ascorbate peroxidase in the antisense line increased after 8 h of MHL, supporting the compensatory effect of the antioxidant system when AOX1a expression is suppressed. This study emphasizes the role played by AOX in modulating the photoprotection processes and in the maintenance of relationships between mitochondria and chloroplasts by influencing ascorbate content.
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15
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Wegner LH. Empowering roots-Some current aspects of root bioenergetics. Front Plant Sci 2022; 13:853309. [PMID: 36051301 PMCID: PMC9424547 DOI: 10.3389/fpls.2022.853309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Roots of higher plants provide the shoot with nutrients and water. In exchange, they receive photosynthates, which serve both as energy source and building blocks for maintenance and growth. While studies in plant bioenergetics used to focus on photosynthesis, several more recent findings also aroused or renewed interest in energy conversion and allocation in roots. Root building costs were identified as a long-undervalued trait, which turned out to be highly relevant for stress tolerance and nutrient use efficiency. Reduced building costs per root length (e.g., by aerenchyma formation or by increasing the cell size) are beneficial for exploring the soil for nutrient-rich patches, especially in low-input agrosystems. Also, an apparent mismatch was frequently found between the root energy budget in the form of the ATP pool on the one side and the apparent costs on the other side, particularly the costs of membrane transport under stress conditions, e.g., the Na+ detoxification costs resulting from Na+ sequestration at the plasma membrane. Ion transport across the plasma membrane (and also endomembranes) is coupled to the proton motive force usually believed to be exclusively generated by H+ ATPases. Recently, an alternative mechanism, the biochemical pH clamp, was identified which relies on H+ formation and binding in the apoplast and the cytosol, respectively, driven by metabolism (so-called active buffering). On this background, several aspects of root bioenergetics are discussed. These are (1) root respiration in soil, with a critical view on calorimetric vs. gas exchange measurements; (2) processes of energy conversion in mitochondria with a special focus on the role of the alternative oxidases, which allow adjusting carbon flow through metabolic pathways to membrane transport processes; and (3) energy allocation, in particular to transport across the plasma membrane forming the interface to soil solution. A concluding remark is dedicated to modeling root bioenergetics for optimizing further breeding strategies. Apparent "energy spoilers" may bestow the plant with a yet unidentified advantage only unfolding their beneficial effect under certain environmental conditions.
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16
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Szibor M, Schenkl C, Barsottini MRO, Young L, Moore AL. Targeting the alternative oxidase (AOX) for human health and food security, a pharmaceutical and agrochemical target or a rescue mechanism? Biochem J 2022; 479:1337-59. [PMID: 35748702 DOI: 10.1042/BCJ20180192] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/23/2022] [Accepted: 06/07/2022] [Indexed: 11/25/2022]
Abstract
Some of the most threatening human diseases are due to a blockage of the mitochondrial electron transport chain (ETC). In a variety of plants, fungi, and prokaryotes, there is a naturally evolved mechanism for such threats to viability, namely a bypassing of the blocked portion of the ETC by alternative enzymes of the respiratory chain. One such enzyme is the alternative oxidase (AOX). When AOX is expressed, it enables its host to survive life-threatening conditions or, as in parasites, to evade host defenses. In vertebrates, this mechanism has been lost during evolution. However, we and others have shown that transfer of AOX into the genome of the fruit fly and mouse results in a catalytically engaged AOX. This implies that not only is the AOX a promising target for combating human or agricultural pathogens but also a novel approach to elucidate disease mechanisms or, in several cases, potentially a therapeutic cure for human diseases. In this review, we highlight the varying functions of AOX in their natural hosts and upon xenotopic expression, and discuss the resulting need to develop species-specific AOX inhibitors.
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17
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Zafari S, Vanlerberghe GC, Igamberdiev AU. The Role of Alternative Oxidase in the Interplay between Nitric Oxide, Reactive Oxygen Species, and Ethylene in Tobacco ( Nicotiana tabacum L.) Plants Incubated under Normoxic and Hypoxic Conditions. Int J Mol Sci 2022; 23:7153. [PMID: 35806157 PMCID: PMC9266549 DOI: 10.3390/ijms23137153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 06/24/2022] [Indexed: 02/05/2023] Open
Abstract
The transgenic tobacco (Nicotiana tabacum L.) plants with the modified levels of alternative oxidase (AOX) were used to evaluate the physiological roles of AOX in regulating nitro-oxidative stress and metabolic changes after exposing plants to hypoxia for 6 h. Under normoxia, AOX expression resulted in the decrease of nitric oxide (NO) levels and of the rate of protein S-nitrosylation, while under hypoxia, AOX overexpressors exhibited higher NO and S-nitrosylation levels than knockdowns. AOX expression was essential in avoiding hypoxia-induced superoxide and H2O2 levels, and this was achieved via higher activities of catalase and glutathione reductase and the reduced expression of respiratory burst oxidase homolog (Rboh) in overexpressors as compared to knockdowns. The AOX overexpressing lines accumulated less pyruvate and exhibited the increased transcript and activity levels of pyruvate decarboxylase and alcohol dehydrogenase under hypoxia. This suggests that AOX contributes to the energy state of hypoxic tissues by stimulating the increase of pyruvate flow into fermentation pathways. Ethylene biosynthesis genes encoding 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, ACC oxidase, and ethylene-responsive factors (ERFs) were induced during hypoxia and correlated with AOX and NO levels. We conclude that AOX controls the interaction of NO, reactive oxygen species, and ethylene, triggering a coordinated downstream defensive response against hypoxia.
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Affiliation(s)
- Somaieh Zafari
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada;
- Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada
| | - Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
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18
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Del-Saz NF, Iglesias-Sanchez A, Alonso-Forn D, López-Gómez M, Palma F, Clemente-Moreno MJ, Fernie AR, Ribas-Carbo M, Florez-Sarasa I. The Lack of Alternative Oxidase 1a Restricts in vivo Respiratory Activity and Stress-Related Metabolism for Leaf Osmoprotection and Redox Balancing Under Sudden Acute Water and Salt Stress in Arabidopsis thaliana. Front Plant Sci 2022; 13:833113. [PMID: 35656009 PMCID: PMC9152546 DOI: 10.3389/fpls.2022.833113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
In plants salt and water stress result in an induction of respiration and accumulation of stress-related metabolites (SRMs) with osmoregulation and osmoprotection functions that benefit photosynthesis. The synthesis of SRMs may depend on an active respiratory metabolism, which can be restricted under stress by the inhibition of the cytochrome oxidase pathway (COP), thus causing an increase in the reduction level of the ubiquinone pool. However, the activity of the alternative oxidase pathway (AOP) is thought to prevent this from occurring while at the same time, dissipates excess of reducing power from the chloroplast and thereby improves photosynthetic performance. The present research is based on the hypothesis that the accumulation of SRMs under osmotic stress will be affected by changes in folial AOP activity. To test this, the oxygen isotope-fractionation technique was used to study the in vivo respiratory activities of COP and AOP in leaves of wild-type Arabidopsis thaliana plants and of aox1a mutants under sudden acute stress conditions induced by mannitol and salt treatments. Levels of leaf primary metabolites and transcripts of respiratory-related proteins were also determined in parallel to photosynthetic analyses. The lack of in vivo AOP response in the aox1a mutants coincided with a lower leaf relative water content and a decreased accumulation of crucial osmoregulators. Additionally, levels of oxidative stress-related metabolites and transcripts encoding alternative respiratory components were increased. Coordinated changes in metabolite levels, respiratory activities and photosynthetic performance highlight the contribution of the AOP in providing flexibility to carbon metabolism for the accumulation of SRMs.
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Affiliation(s)
- Néstor F. Del-Saz
- Laboratorio de Fisiología Vegetal, Universidad de Concepción, Concepción, Chile
| | | | - David Alonso-Forn
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Zaragoza, Spain
| | | | - Francisco Palma
- Department of Plant Physiology, University of Granada, Granada, Spain
| | - María José Clemente-Moreno
- Grup de Recerca en Biologia de les Plantes en Condicions Mediterranies, Departament de Biologia, Universitat de les Illes Balears, Palma, Spain
| | | | - Miquel Ribas-Carbo
- Grup de Recerca en Biologia de les Plantes en Condicions Mediterranies, Departament de Biologia, Universitat de les Illes Balears, Palma, Spain
| | - Igor Florez-Sarasa
- Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, Barcelona, Spain
- Institut de Recerca i Tecnología Agroalimentàries (IRTA), Edifici CRAG, Barcelona, Spain
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19
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Bychkov IA, Kudryakova NV, Shugaev AG, Kuznetsov VV, Kusnetsov VV. The Melatonin Receptor CAND2/PMTR1 Is Involved in the Regulation of Mitochondrial Gene Expression under Photooxidative Stress. DOKL BIOCHEM BIOPHYS 2022; 502:15-20. [PMID: 35275300 DOI: 10.1134/s1607672922010021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/21/2021] [Accepted: 09/21/2021] [Indexed: 01/21/2023]
Abstract
Melatonin is a signaling molecule that mediates multiple stress-dependent reactions. Under photooxidative stress conditions generating intensive ROS production, exogenous melatonin (50 µM) contributed to maintaining the expression of mitochondrial encoded genes and up-regulation of RNA-polymerase genes RPOTm and RPOTmp, operating through the CAND2 receptor and α-subunit of the heterotrimeric G protein GPA1 coupled with CAND2. Unlike wild-type plants, mutants with defective CAND2 and GPA1 genes exhibited no decrease in the alternative pathway of leaf respiration, as well as the activity of an alternative oxidase, and the expression of the AOX1a gene. At the same time, the protective effect of exogenous melatonin on some physiological indicators did not depend on the receptor and was associated with the direct antioxidant function of the regulator. Thus, melatonin under photooxidative stress conditions can act as an antioxidant and as a hormone capable of regulating the expression of nuclear and organelle genes through the components of melatonin signal perception.
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Affiliation(s)
- I A Bychkov
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia.
| | - N V Kudryakova
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia
| | - A G Shugaev
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia
| | - Vl V Kuznetsov
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia
| | - V V Kusnetsov
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia
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20
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Sweetman C, Selinski J, Miller TK, Whelan J, Day DA. Legume Alternative Oxidase Isoforms Show Differential Sensitivity to Pyruvate Activation. Front Plant Sci 2022; 12:813691. [PMID: 35111186 PMCID: PMC8801435 DOI: 10.3389/fpls.2021.813691] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 12/27/2021] [Indexed: 05/29/2023]
Abstract
Alternative oxidase (AOX) is an important component of the plant respiratory pathway, enabling a route for electrons that bypasses the energy-conserving, ROS-producing complexes of the mitochondrial electron transport chain. Plants contain numerous isoforms of AOX, classified as either AOX1 or AOX2. AOX1 isoforms have received the most attention due to their importance in stress responses across a wide range of species. However, the propensity for at least one isoform of AOX2 to accumulate to very high levels in photosynthetic tissues of all legumes studied to date, suggests that this isoform has specialized roles, but we know little of its properties. Previous studies with sub-mitochondrial particles of soybean cotyledons and roots indicated that differential expression of GmAOX1, GmAOX2A, and GmAOX2D across tissues might confer different activation kinetics with pyruvate. We have investigated this using recombinantly expressed isoforms of soybean AOX in a previously described bacterial system (Selinski et al., 2016, Physiologia Plantarum 157, 264-279). Pyruvate activation kinetics were similar between the two GmAOX2 isoforms but differed substantially from those of GmAOX1, suggesting that selective expression of AOX1 and 2 could determine the level of AOX activity. However, this alone cannot completely explain the differences seen in sub-mitochondrial particles isolated from different legume tissues and possible reasons for this are discussed.
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Affiliation(s)
- Crystal Sweetman
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Jennifer Selinski
- Department of Plant Cell Biology, Botanical Institute, Christian-Albrecht University of Kiel, Kiel, Germany
| | - Troy K. Miller
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - James Whelan
- Department of Animal, Plant, and Soil Science, School of Soil Science, La Trobe University, Bundoora, VIC, Australia
| | - David A. Day
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
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21
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Sankar TV, Saharay M, Santhosh D, Vishwakarma A, Padmasree K. Structural and Biophysical Characterization of Purified Recombinant Arabidopsis thaliana's Alternative Oxidase 1A (rAtAOX1A): Interaction With Inhibitor(s) and Activator. Front Plant Sci 2022; 13:871208. [PMID: 35783971 PMCID: PMC9243770 DOI: 10.3389/fpls.2022.871208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/27/2022] [Indexed: 05/14/2023]
Abstract
In higher plants, alternative oxidase (AOX) participates in a cyanide resistant and non-proton motive electron transport pathway of mitochondria, diverging from the ubiquinone pool. The physiological significance of AOX in biotic/abiotic stress tolerance is well-documented. However, its structural and biophysical properties are poorly understood as its crystal structure is not yet revealed in plants. Also, most of the AOX purification processes resulted in a low yield/inactive/unstable form of native AOX protein. The present study aims to characterize the purified rAtAOX1A protein and its interaction with inhibitors, such as salicylhydroxamic acid (SHAM) and n-propyl gallate (n-PG), as well as pyruvate (activator), using biophysical/in silico studies. The rAtAOX1A expressed in E. coli BL21(DE3) cells was functionally characterized by monitoring the respiratory and growth sensitivity of E. coli/pAtAOX1A and E. coli/pET28a to classical mitochondrial electron transport chain (mETC) inhibitors. The rAtAOX1A, which is purified through affinity chromatography and confirmed by western blotting and MALDI-TOF-TOF studies, showed an oxygen uptake activity of 3.86 μmol min-1 mg-1 protein, which is acceptable in non-thermogenic plants. Circular dichroism (CD) studies of purified rAtAOX1A revealed that >50% of the protein content was α-helical and retained its helical absorbance signal (ellipticity) at a wide range of temperature and pH conditions. Further, interaction with SHAM, n-PG, or pyruvate caused significant changes in its secondary structural elements while retaining its ellipticity. Surface plasmon resonance (SPR) studies revealed that both SHAM and n-PG bind reversibly to rAtAOX1A, while docking studies revealed that they bind to the same hydrophobic groove (Met191, Val192, Met195, Leu196, Phe251, and Phe255), to which Duroquinone (DQ) bind in the AtAOX1A. In contrast, pyruvate binds to a pocket consisting of Cys II (Arg174, Tyr175, Gly176, Cys177, Val232, Ala233, Asn294, and Leu313). Further, the mutational docking studies suggest that (i) the Met195 and Phe255 of AtAOX1A are the potential candidates to bind the inhibitor. Hence, this binding pocket could be a 'potential gateway' for the oxidation-reduction process in AtAOX1A, and (ii) Arg174, Gly176, and Cys177 play an important role in binding to the organic acids like pyruvate.
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Affiliation(s)
- Tadiboina Veera Sankar
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Moumita Saharay
- Department of Systems and Computational Biology, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Dharawath Santhosh
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Abhaypratap Vishwakarma
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, India
- Department of Botany, Deshbandhu College, University of Delhi, New Delhi, India
| | - Kollipara Padmasree
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
- *Correspondence: Kollipara Padmasree
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Kumari A, Singh P, Kaladhar VC, Paul D, Pathak PK, Gupta KJ. Phytoglobin-NO cycle and AOX pathway play a role in anaerobic germination and growth of deepwater rice. Plant Cell Environ 2022; 45:178-190. [PMID: 34633089 DOI: 10.1111/pce.14198] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
An important and interesting feature of rice is that it can germinate under anoxic conditions. Though several biochemical adaptive mechanisms play an important role in the anaerobic germination of rice but the role of phytoglobin-nitric oxide cycle and alternative oxidase pathway is not known, therefore in this study we investigated the role of these pathways in anaerobic germination. Under anoxic conditions, deepwater rice germinated much higher and rapidly than aerobic condition and the anaerobic germination and growth were much higher in the presence of nitrite. The addition of nitrite stimulated NR activity and NO production. Important components of phytoglobin-NO cycle such as methaemoglobin reductase activity, expression of Phytoglobin1, NIA1 were elevated under anaerobic conditions in the presence of nitrite. The operation of phytoglobin-NO cycle also enhanced anaerobic ATP generation, LDH, ADH activities and in parallel ethylene levels were also enhanced. Interestingly nitrite suppressed the ROS production and lipid peroxidation. The reduction of ROS was accompanied by enhanced expression of mitochondrial alternative oxidase protein and its capacity. Application of AOX inhibitor SHAM inhibited the anoxic growth mediated by nitrite. In addition, nitrite improved the submergence tolerance of seedlings. Our study revealed that nitrite driven phytoglobin-NO cycle and AOX are crucial players in anaerobic germination and growth of deepwater rice.
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Affiliation(s)
- Aprajita Kumari
- National Institute for Plant Genome Research, New Delhi, India
- Amity Institute of Biotechnology, Amity University, Noida, India
| | - Pooja Singh
- National Institute for Plant Genome Research, New Delhi, India
| | | | - Debarati Paul
- Amity Institute of Biotechnology, Amity University, Noida, India
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Rodrigues L, Nogales A, Hansen LD, Santos F, Rato AE, Cardoso H. Exploring the Applicability of Calorespirometry to Assess Seed Metabolic Stability Upon Temperature Stress Conditions- Pisum sativum L. Used as a Case Study. Front Plant Sci 2022; 13:827117. [PMID: 35574105 PMCID: PMC9094064 DOI: 10.3389/fpls.2022.827117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/24/2022] [Indexed: 05/17/2023]
Abstract
The availability of phenotyping tools to assist breeding programs in the selection of high-quality crop seeds is of obvious interest with consequences for both seed producers and consumers. Seed germination involves the activation of several metabolic pathways, such as cellular respiration to provide the required ATP and reducing power. This work tested the applicability of calorespirometry, the simultaneous measurement of heat and CO2 rates, as a phenotyping tool to assess seed respiratory properties as a function of temperature. The effect of temperature on seed germination was evaluated after 16 h of seed imbibition by calorespirometric experiments performed in isothermal mode at 15, 20, 25, and 28°C on the seeds of three cultivars of peas (Pisum sativum L.) commonly used in conventional agriculture (cvs. 'Rondo', 'Torta de Quebrar', and 'Maravilha d'América'). Significant differences in metabolic heat rate and CO2 production rate (R CO2 ) as well as in the temperature responses of these parameters were found among the three cultivars. A seed germination trial was conducted during the 6 days of imbibition to evaluate the predictive power of the parameters derived from the calorespirometric measurements. The germination trial showed that the optimal germination temperature was 20°C and low germination rates were observed at extreme temperatures (15 or 28°C). The cv. 'Torta de Quebrar' showed significantly higher germination in comparison with the other two cultivars at all three temperatures. In comparison with the other two cultivars, 'Torta de Quebrar' has the lowest metabolic heat and CO2 rates and the smallest temperature dependence of these measured parameters. Additionally, 'Torta de Quebrar' has the lowest values of growth rate and carbon use efficiency calculated from the measured variables. These data suggest that calorespirometry is a useful tool for phenotyping physiologic efficiency at different temperatures during early germination stages, and can determine the seeds with the highest resilience to temperature variation, in this case 'Torta de Quebrar'.
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Affiliation(s)
- Lénia Rodrigues
- Mediterranean Institute for Agriculture, Environment and Development, Instituto de Formação e Investigação Avançada, Universidade de Évora, Évora, Portugal
| | - Amaia Nogales
- Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal
| | - Lee D. Hansen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, United States
| | - Fátima Santos
- Centro Nacional de Biotecnología, Unidad de Proteomica, CSIC, Calle Darwin 3, Madrid, Spain
| | - Ana Elisa Rato
- Mediterranean Institute for Agriculture, Environment and Development, Departamento de Fitotecnia, Escola de Ciências e Tecnologia, Universidade de Évora, Évora, Portugal
| | - Hélia Cardoso
- Mediterranean Institute for Agriculture, Environment and Development, Instituto de Formação e Investigação Avançada, Universidade de Évora, Évora, Portugal
- *Correspondence: Hélia Cardoso,
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Pandey S, Kumari A, Singh P, Gupta KJ. Isolation and Measurement of Respiration and Structural Studies of Purified Mitochondria from Heterotrophic Plant Tissues. Curr Protoc 2021; 1:e326. [PMID: 34919353 DOI: 10.1002/cpz1.326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mitochondria are the power houses of eukaryotic cells. These organelles contain various oxidoreductase complexes. Electron transfer from different reducing equivalents channeled via these complexes drives proton translocation across the inner mitochondrial membrane, leading to ATP generation. Plant mitochondria contain alternative NAD(P)H dehydrogenases, alternative oxidase, and uncoupling protein, and TCA cycle enzymes are located in their matrix. Apart from ATP production, mitochondria are also involved in synthesis of vitamins and cofactors and participate in fatty acid, nucleotide, photorespiratory, and antioxidant metabolism. Recent emerging evidence suggests that mitochondria play a role in redox signaling and generation of reactive oxygen and nitrogen species. For mitochondrial studies, it is essential to isolate physiologically active mitochondria with good structural integrity. In this article, we explain a detailed procedure for isolation of mitochondria from various heterotrophic tissues, such as germinating chickpea seeds, potato tubers, and cauliflower florets. This procedure requires discontinuous Percoll gradient centrifugation and can give a good yield of mitochondria, in the range of 4 to 8 mg per 50 g tissue with active respiratory capacity. After MitoTracker staining, isolated mitochondria can be visualized by using a confocal microscope. The structure of mitochondria can be monitored by scanning electron microscopy. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Isolation of mitochondria from germinating chickpea seeds, potato tubers, and cauliflower florets Basic Protocol 2: Quantification of mitochondrial protein concentration by Bradford assay Basic Protocol 3: Quantification of mitochondrial respiration using single-channel free-radical analyzer Basic Protocol 4: Staining of mitochondria and confocal imaging Basic Protocol 5: Visualization of isolated mitochondria under scanning electron microscope.
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Affiliation(s)
- Sonika Pandey
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Aprajita Kumari
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Pooja Singh
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
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Campos MD, Campos C, Nogales A, Cardoso H. Carrot AOX2a Transcript Profile Responds to Growth and Chilling Exposure. Plants (Basel) 2021; 10:plants10112369. [PMID: 34834732 PMCID: PMC8625938 DOI: 10.3390/plants10112369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 10/28/2021] [Accepted: 10/29/2021] [Indexed: 05/28/2023]
Abstract
Alternative oxidase (AOX) is a key enzyme of the alternative respiration, known to be involved in plant development and in response to various stresses. To verify the role of DcAOX1 and DcAOX2a genes in carrot tap root growth and in response to cold stress, their expression was analyzed in two experiments: during root growth for 13 weeks and in response to a cold challenge trial of 7 days, in both cases using different carrot cultivars. Carrot root growth is initially characterized by an increase in length, followed by a strong increase in weight. DcAOX2a presented the highest expression levels during the initial stages of root growth for all cultivars, but DcAOX1 showed no particular trend in expression. Cold stress had a negative impact on root growth, and generally up-regulated DcAOX2a with no consistent effect on DcAOX1. The identification of cis-acting regulatory elements (CAREs) located at the promoters of both genes showed putative sequences involved in cold stress responsiveness, as well as growth. However, DcAOX2a promoter presented more CAREs related to hormonal pathways, including abscisic acid and gibberellins synthesis, than DcAOX1. These results point to a dual role of DcAOX2a on carrot tap root secondary growth and cold stress response.
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Affiliation(s)
- Maria Doroteia Campos
- MED—Mediterranean Institute for Agriculture, Environment and Development, Instituto de Investigação e Formação Avançada, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal; (C.C.); (A.N.)
| | - Catarina Campos
- MED—Mediterranean Institute for Agriculture, Environment and Development, Instituto de Investigação e Formação Avançada, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal; (C.C.); (A.N.)
| | - Amaia Nogales
- MED—Mediterranean Institute for Agriculture, Environment and Development, Instituto de Investigação e Formação Avançada, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal; (C.C.); (A.N.)
- LEAF—Linking Landscape, Environment, Agriculture and Food Research Center, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
| | - Hélia Cardoso
- MED—Mediterranean Institute for Agriculture, Environment and Development, Instituto de Investigação e Formação Avançada, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal; (C.C.); (A.N.)
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26
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Møller IM, Rasmusson AG, Van Aken O. Plant mitochondria - past, present and future. Plant J 2021; 108:912-959. [PMID: 34528296 DOI: 10.1111/tpj.15495] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 09/02/2021] [Accepted: 09/06/2021] [Indexed: 06/13/2023]
Abstract
The study of plant mitochondria started in earnest around 1950 with the first isolations of mitochondria from animal and plant tissues. The first 35 years were spent establishing the basic properties of plant mitochondria and plant respiration using biochemical and physiological approaches. A number of unique properties (compared to mammalian mitochondria) were observed: (i) the ability to oxidize malate, glycine and cytosolic NAD(P)H at high rates; (ii) the partial insensitivity to rotenone, which turned out to be due to the presence of a second NADH dehydrogenase on the inner surface of the inner mitochondrial membrane in addition to the classical Complex I NADH dehydrogenase; and (iii) the partial insensitivity to cyanide, which turned out to be due to an alternative oxidase, which is also located on the inner surface of the inner mitochondrial membrane, in addition to the classical Complex IV, cytochrome oxidase. With the appearance of molecular biology methods around 1985, followed by genomics, further unique properties were discovered: (iv) plant mitochondrial DNA (mtDNA) is 10-600 times larger than the mammalian mtDNA, yet it only contains approximately 50% more genes; (v) plant mtDNA has kept the standard genetic code, and it has a low divergence rate with respect to point mutations, but a high recombinatorial activity; (vi) mitochondrial mRNA maturation includes a uniquely complex set of activities for processing, splicing and editing (at hundreds of sites); (vii) recombination in mtDNA creates novel reading frames that can produce male sterility; and (viii) plant mitochondria have a large proteome with 2000-3000 different proteins containing many unique proteins such as 200-300 pentatricopeptide repeat proteins. We describe the present and fairly detailed picture of the structure and function of plant mitochondria and how the unique properties make their metabolism more flexible allowing them to be involved in many diverse processes in the plant cell, such as photosynthesis, photorespiration, CAM and C4 metabolism, heat production, temperature control, stress resistance mechanisms, programmed cell death and genomic evolution. However, it is still a challenge to understand how the regulation of metabolism and mtDNA expression works at the cellular level and how retrograde signaling from the mitochondria coordinates all those processes.
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Affiliation(s)
- Ian Max Møller
- Department of Molecular Biology and Genetics, Aarhus University, Forsøgsvej 1, DK-4200, Slagelse, Denmark
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Belykh ES, Velegzhaninov IO, Garmash EV. Responses of genes of DNA repair, alternative oxidase, and pro-/antioxidant state in Arabidopsis thaliana with altered expression of AOX1a to gamma irradiation. Int J Radiat Biol 2021; 98:60-68. [PMID: 34714725 DOI: 10.1080/09553002.2022.1998712] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE High doses of gamma (γ) irradiation cause oxidative stress and DNA damage. Alternative oxidase (AOX) catalyzes the energy-dissipating cyanide-resistant alternative pathway in plant mitochondria and is an important part of the cellular defense network under stress conditions. In this study, Arabidopsis thaliana plants with an altered expression of the AOX1a gene were exposed by high dose-rate ionizing radiation to assess the expression of genes of DNA repair and pro-/antioxidant states to elucidate the functional significance of AOX in plant stress response. MATERIALS AND METHODS Five-week-old A. thaliana plants, either with basal AOX1a gene expression (wild-type Colombia-0 (Col-0)), antisense silencing of AOX1a (AS-12), and overexpression of the gene (XX-2), were γ-irradiated at a dose of 200 Gy. Gene expression and biochemical analyses were performed 12 h after irradiation. RESULTS Acute γ-irradiation caused different responses between the genotypes. XX-2 plants, either control or irradiated, showed the highest expression of AOX1a gene and AOX protein, and the lowest expression of DNA repair genes. Wild type and AS-12 plants exposed to γ-irradiation upregulated another stress-induced gene, AOX1d, and DNA repair genes. Furthermore, a higher activity of Mn-dependent superoxide dismutase (Mn-SOD) was observed in the irradiated AS-12 plants than in the untreated plants of this line. However, AS-12 plants were less effective than Col-0 plants in controlling the accumulation of the superoxide anion. XX-2 plants had the lowest reactive oxygen species (ROS) levels among the genotypes. CONCLUSIONS AS-12 plants display a compensatory mechanism by increasing the expression of AOX1d and the synthesis of the AOX protein, as well as by Mn-SOD activation. However, these were insufficient to maintain the background level of embryonic lethal mutations, and thereby the reproductive capacity. These results highlight the importance of AOX in the successful adaptation of plants to acute γ-irradiation, and indicate that AOX1a plays a key role in the regulation of the stress response.
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Affiliation(s)
- Elena S Belykh
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Ilya O Velegzhaninov
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Elena V Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
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Xu F, Copsey AC, Young L, Barsottini MRO, Albury MS, Moore AL. Comparison of the Kinetic Parameters of Alternative Oxidases From Trypanosoma brucei and Arabidopsis thaliana-A Tale of Two Cavities. Front Plant Sci 2021; 12:744218. [PMID: 34745175 PMCID: PMC8569227 DOI: 10.3389/fpls.2021.744218] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/21/2021] [Indexed: 05/27/2023]
Abstract
The alternative oxidase (AOX) is widespread in plants, fungi, and some protozoa. While the general structure of the AOX remains consistent, its overall activity, sources of kinetic activation and their sensitivity to inhibitors varies between species. In this study, the recombinant Trypanosoma brucei AOX (rTAO) and Arabidopsis thaliana AOX1A (rAtAOX1A) were expressed in the Escherichia coli ΔhemA mutant FN102, and the kinetic parameters of purified AOXs were compared. Results showed that rTAO possessed the highest V max and K m for quinol-1, while much lower V max and K m were observed in the rAtAOX1A. The catalytic efficiency (k cat/K m) of rTAO was higher than that of rAtAOX1A. The rTAO also displayed a higher oxygen affinity compared to rAtAOX1A. It should be noted that rAtAOX1a was sensitive to α-keto acids while rTAO was not. Nevertheless, only pyruvate and glyoxylate can fully activate Arabidopsis AOX. In addition, rTAO and rAtAOX1A showed different sensitivity to AOX inhibitors, with ascofuranone (AF) being the best inhibitor against rTAO, while colletochlorin B (CB) appeared to be the most effective inhibitor against rAtAOX1A. Octylgallate (OG) and salicylhydroxamic acid (SHAM) are less effective than the other inhibitors against protist and plant AOX. A Caver analysis indicated that the rTAO and rAtAOX1A differ with respect to the mixture of polar residues lining the hydrophobic cavity, which may account for the observed difference in kinetic and inhibitor sensitivities. The data obtained in this study are not only beneficial for our understanding of the variation in the kinetics of AOX within protozoa and plants but also contribute to the guidance for the future development of phytopathogenic fungicides.
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Pérez G, Lopez-Moya F, Chuina E, Ibañez-Vea M, Garde E, López-Llorca LV, Pisabarro AG, Ramírez L. Strain Degeneration in Pleurotus ostreatus: A Genotype Dependent Oxidative Stress Process Which Triggers Oxidative Stress, Cellular Detoxifying and Cell Wall Reshaping Genes. J Fungi (Basel) 2021; 7:jof7100862. [PMID: 34682283 PMCID: PMC8537115 DOI: 10.3390/jof7100862] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/08/2021] [Accepted: 10/09/2021] [Indexed: 12/13/2022] Open
Abstract
Strain degeneration has been defined as a decrease or loss in the yield of important commercial traits resulting from subsequent culture, which ultimately leads to Reactive Oxygen Species (ROS) production. Pleurotus ostreatus is a lignin-producing nematophagous edible mushroom. Mycelia for mushroom production are usually maintained in subsequent culture in solid media and frequently show symptoms of strain degeneration. The dikaryotic strain P. ostreatus (DkN001) has been used in our lab as a model organism for different purposes. Hence, different tools have been developed to uncover genetic and molecular aspects of this fungus. In this work, strain degeneration was studied in a full-sib monokaryotic progeny of the DkN001 strain with fast (F) and slow (S) growth rates by using different experimental approaches (light microscopy, malondialdehyde levels, whole-genome transcriptome analysis, and chitosan effect on monokaryotic mycelia). The results obtained showed that: (i) strain degeneration in P. ostreatus is linked to oxidative stress, (ii) the oxidative stress response in monokaryons is genotype dependent, (iii) stress and detoxifying genes are highly expressed in S monokaryons with symptoms of strain degeneration, (iv) chitosan addition to F and S monokaryons uncovered the constitutive expression of both oxidative stress and cellular detoxifying genes in S monokaryon strains which suggest their adaptation to oxidative stress, and (v) the overexpression of the cell wall genes, Uap1 and Cda1, in S monokaryons with strain degeneration phenotype indicates cell wall reshaping and the activation of High Osmolarity Glycerol (HOG) and Cell Wall Integrity (CWI) pathways. These results could constitute a hallmark for mushroom producers to distinguish strain degeneration in commercial mushrooms.
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Affiliation(s)
- Gumer Pérez
- Genetics, Genomics and Microbiology Research Group, Institute for Multidisciplinary Research in Applied Biology (IMAB), Public University of Navarre (UPNA), 31006 Pamplona, Spain; (G.P.); (E.C.); (M.I.-V.); (E.G.); (A.G.P.)
| | - Federico Lopez-Moya
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, University of Alicante, 03690 Alicante, Spain; (F.L.-M.); (L.V.L.-L.)
| | - Emilia Chuina
- Genetics, Genomics and Microbiology Research Group, Institute for Multidisciplinary Research in Applied Biology (IMAB), Public University of Navarre (UPNA), 31006 Pamplona, Spain; (G.P.); (E.C.); (M.I.-V.); (E.G.); (A.G.P.)
| | - María Ibañez-Vea
- Genetics, Genomics and Microbiology Research Group, Institute for Multidisciplinary Research in Applied Biology (IMAB), Public University of Navarre (UPNA), 31006 Pamplona, Spain; (G.P.); (E.C.); (M.I.-V.); (E.G.); (A.G.P.)
| | - Edurne Garde
- Genetics, Genomics and Microbiology Research Group, Institute for Multidisciplinary Research in Applied Biology (IMAB), Public University of Navarre (UPNA), 31006 Pamplona, Spain; (G.P.); (E.C.); (M.I.-V.); (E.G.); (A.G.P.)
| | - Luis V. López-Llorca
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, University of Alicante, 03690 Alicante, Spain; (F.L.-M.); (L.V.L.-L.)
| | - Antonio G. Pisabarro
- Genetics, Genomics and Microbiology Research Group, Institute for Multidisciplinary Research in Applied Biology (IMAB), Public University of Navarre (UPNA), 31006 Pamplona, Spain; (G.P.); (E.C.); (M.I.-V.); (E.G.); (A.G.P.)
| | - Lucía Ramírez
- Genetics, Genomics and Microbiology Research Group, Institute for Multidisciplinary Research in Applied Biology (IMAB), Public University of Navarre (UPNA), 31006 Pamplona, Spain; (G.P.); (E.C.); (M.I.-V.); (E.G.); (A.G.P.)
- Correspondence:
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Chadee A, Alber NA, Dahal K, Vanlerberghe GC. The Complementary Roles of Chloroplast Cyclic Electron Transport and Mitochondrial Alternative Oxidase to Ensure Photosynthetic Performance. Front Plant Sci 2021; 12:748204. [PMID: 34650584 PMCID: PMC8505746 DOI: 10.3389/fpls.2021.748204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 08/30/2021] [Indexed: 05/29/2023]
Abstract
Chloroplasts use light energy and a linear electron transport (LET) pathway for the coupled generation of NADPH and ATP. It is widely accepted that the production ratio of ATP to NADPH is usually less than required to fulfill the energetic needs of the chloroplast. Left uncorrected, this would quickly result in an over-reduction of the stromal pyridine nucleotide pool (i.e., high NADPH/NADP+ ratio) and under-energization of the stromal adenine nucleotide pool (i.e., low ATP/ADP ratio). These imbalances could cause metabolic bottlenecks, as well as increased generation of damaging reactive oxygen species. Chloroplast cyclic electron transport (CET) and the chloroplast malate valve could each act to prevent stromal over-reduction, albeit in distinct ways. CET avoids the NADPH production associated with LET, while the malate valve consumes the NADPH associated with LET. CET could operate by one of two different pathways, depending upon the chloroplast ATP demand. The NADH dehydrogenase-like pathway yields a higher ATP return per electron flux than the pathway involving PROTON GRADIENT REGULATION5 (PGR5) and PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE1 (PGRL1). Similarly, the malate valve could couple with one of two different mitochondrial electron transport pathways, depending upon the cytosolic ATP demand. The cytochrome pathway yields a higher ATP return per electron flux than the alternative oxidase (AOX) pathway. In both Arabidopsis thaliana and Chlamydomonas reinhardtii, PGR5/PGRL1 pathway mutants have increased amounts of AOX, suggesting complementary roles for these two lesser-ATP yielding mechanisms of preventing stromal over-reduction. These two pathways may become most relevant under environmental stress conditions that lower the ATP demands for carbon fixation and carbohydrate export.
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Affiliation(s)
- Avesh Chadee
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Nicole A. Alber
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Keshav Dahal
- Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, Fredericton, NB, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
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Costa JH, Mohanapriya G, Bharadwaj R, Noceda C, Thiers KLL, Aziz S, Srivastava S, Oliveira M, Gupta KJ, Kumari A, Sircar D, Kumar SR, Achra A, Sathishkumar R, Adholeya A, Arnholdt-Schmitt B. ROS/RNS Balancing, Aerobic Fermentation Regulation and Cell Cycle Control - a Complex Early Trait ('CoV-MAC-TED') for Combating SARS-CoV-2-Induced Cell Reprogramming. Front Immunol 2021; 12:673692. [PMID: 34305903 PMCID: PMC8293103 DOI: 10.3389/fimmu.2021.673692] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 06/17/2021] [Indexed: 12/19/2022] Open
Abstract
In a perspective entitled 'From plant survival under severe stress to anti-viral human defense' we raised and justified the hypothesis that transcript level profiles of justified target genes established from in vitro somatic embryogenesis (SE) induction in plants as a reference compared to virus-induced profiles can identify differential virus signatures that link to harmful reprogramming. A standard profile of selected genes named 'ReprogVirus' was proposed for in vitro-scanning of early virus-induced reprogramming in critical primary infected cells/tissues as target trait. For data collection, the 'ReprogVirus platform' was initiated. This initiative aims to identify in a common effort across scientific boundaries critical virus footprints from diverse virus origins and variants as a basis for anti-viral strategy design. This approach is open for validation and extension. In the present study, we initiated validation by experimental transcriptome data available in public domain combined with advancing plant wet lab research. We compared plant-adapted transcriptomes according to 'RegroVirus' complemented by alternative oxidase (AOX) genes during de novo programming under SE-inducing conditions with in vitro corona virus-induced transcriptome profiles. This approach enabled identifying a major complex trait for early de novo programming during SARS-CoV-2 infection, called 'CoV-MAC-TED'. It consists of unbalanced ROS/RNS levels, which are connected to increased aerobic fermentation that links to alpha-tubulin-based cell restructuration and progression of cell cycle. We conclude that anti-viral/anti-SARS-CoV-2 strategies need to rigorously target 'CoV-MAC-TED' in primary infected nose and mouth cells through prophylactic and very early therapeutic strategies. We also discuss potential strategies in the view of the beneficial role of AOX for resilient behavior in plants. Furthermore, following the general observation that ROS/RNS equilibration/redox homeostasis is of utmost importance at the very beginning of viral infection, we highlight that 'de-stressing' disease and social handling should be seen as essential part of anti-viral/anti-SARS-CoV-2 strategies.
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Affiliation(s)
- José Hélio Costa
- Functional Genomics and Bioinformatics Group, Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
| | - Gunasekaran Mohanapriya
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India
| | - Revuru Bharadwaj
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India
| | - Carlos Noceda
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Cell and Molecular Biotechnology of Plants (BIOCEMP)/Industrial Biotechnology and Bioproducts, Departamento de Ciencias de la Vida y de la Agricultura, Universidad de las Fuerzas Armadas-ESPE, Sangolquí, Ecuador
| | - Karine Leitão Lima Thiers
- Functional Genomics and Bioinformatics Group, Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
| | - Shahid Aziz
- Functional Genomics and Bioinformatics Group, Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
| | - Shivani Srivastava
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Centre for Mycorrhizal Research, Sustainable Agriculture Division, The Energy and Resources, Institute (TERI), TERI Gram, Gurugram, India
| | - Manuela Oliveira
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Department of Mathematics and CIMA - Center for Research on Mathematics and Its Applications, Universidade de Évora, Évora, Portugal
| | - Kapuganti Jagadis Gupta
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Aprajita Kumari
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Debabrata Sircar
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand, India
| | - Sarma Rajeev Kumar
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India
| | - Arvind Achra
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Department of Microbiology, Atal Bihari Vajpayee Institute of Medical Sciences & Dr Ram Manohar Lohia Hospital, New Delhi, India
| | - Ramalingam Sathishkumar
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India
| | - Alok Adholeya
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Centre for Mycorrhizal Research, Sustainable Agriculture Division, The Energy and Resources, Institute (TERI), TERI Gram, Gurugram, India
| | - Birgit Arnholdt-Schmitt
- Functional Genomics and Bioinformatics Group, Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
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Liu Y, Yu LL, Peng Y, Geng XX, Xu F. Alternative Oxidase Inhibition Impairs Tobacco Root Development and Root Hair Formation. Front Plant Sci 2021; 12:664792. [PMID: 34249036 PMCID: PMC8264555 DOI: 10.3389/fpls.2021.664792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 04/13/2021] [Indexed: 06/13/2023]
Abstract
Alternative oxidase (AOX) is the terminal oxidase of the mitochondrial respiratory electron transport chain in plant cells and is critical for the balance of mitochondrial hemostasis. In this study, the effect of inhibition of AOX with different concentrations of salicylhydroxamic acid (SHAM) on the tobacco root development was investigated. We show here that AOX inhibition significantly impaired the development of the main root and root hair formation of tobacco. The length of the main root of SHAM-treated tobacco was significantly shorter than that of the control, and no root hairs were formed after treatment with a concentration of 1 mM SHAM or more. The transcriptome analysis showed that AOX inhibition by 1 mM SHAM involved in the regulation of gene expression related to root architecture. A total of 5,855 differentially expressed genes (DEGs) were obtained by comparing SHAM-treated roots with control. Of these, the gene expression related to auxin biosynthesis and perception were significantly downregulated by 1 mM SHAM. Similarly, genes related to cell wall loosening, cell cycle, and root meristem growth factor 1 (RGF1) also showed downregulation on SHAM treatment. Moreover, combined with the results of physiological measurements, the transcriptome analysis demonstrated that AOX inhibition resulted in excessive accumulation of reactive oxygen species in roots, which further induced oxidative damage and cell apoptosis. It is worth noting that when indoleacetic acid (20 nM) and dimethylthiourea (10 mM) were added to the medium containing SHAM, the defects of tobacco root development were alleviated, but to a limited extent. Together, these findings indicated that AOX-mediated respiratory pathway plays a crucial role in the tobacco root development, including root hair formation.
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Affiliation(s)
- Yang Liu
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
| | - Lu-Lu Yu
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
| | - Ye Peng
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
- Biotechnology Research Center, China Three Gorges University, Yichang, China
| | - Xin-Xin Geng
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
| | - Fei Xu
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
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Alber NA, Vanlerberghe GC. The flexibility of metabolic interactions between chloroplasts and mitochondria in Nicotiana tabacum leaf. Plant J 2021; 106:1625-1646. [PMID: 33811402 DOI: 10.1111/tpj.15259] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 05/02/2023]
Abstract
To examine the effect of mitochondrial function on photosynthesis, wild-type and transgenic Nicotiana tabacum with varying amounts of alternative oxidase (AOX) were treated with different respiratory inhibitors. Initially, each inhibitor increased the reduction state of the chloroplast electron transport chain, most severely in AOX knockdowns and least severely in AOX overexpressors. This indicated that the mitochondrion was a necessary sink for photo-generated reductant, contributing to the 'P700 oxidation capacity' of photosystem I. Initially, the Complex III inhibitor myxothiazol and the mitochondrial ATP synthase inhibitor oligomycin caused an increase in photosystem II regulated non-photochemical quenching not evident with the Complex III inhibitor antimycin A (AA). This indicated that the increased quenching depended upon AA-sensitive cyclic electron transport (CET). Following 12 h with oligomycin, the reduction state of the chloroplast electron transport chain recovered in all plant lines. Recovery was associated with large increases in the protein amount of chloroplast ATP synthase and mitochondrial uncoupling protein. This increased the capacity for photophosphorylation in the absence of oxidative phosphorylation and enabled the mitochondrion to act again as a sink for photo-generated reductant. Comparing the AA and myxothiazol treatments at 12 h showed that CET optimized photosystem I quantum yield, depending upon the P700 oxidation capacity. When this capacity was too high, CET drew electrons away from other sinks, moderating the P700+ amount. When P700 oxidation capacity was too low, CET acted as an electron overflow, moderating the amount of reduced P700. This study reveals flexible chloroplast-mitochondrion interactions able to overcome lesions in energy metabolism.
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Affiliation(s)
- Nicole A Alber
- Department of Biological Sciences, Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C1A4, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences, Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C1A4, Canada
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Sakamoto H, Kita K, Matsuzaki M. A Novel 2A-peptide-containing Plasmid to Generate Stable Perkinsus marinus Cells Expressing Organelle-targeted Genes. J Eukaryot Microbiol 2021; 68:e12861. [PMID: 34051022 DOI: 10.1111/jeu.12861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Genetic manipulation techniques for marine protists are not well-established, despite immense efforts. However, Perkinsus marinus is an exception and can be developed as a genetically tractable model organism for related protists. Here, we designed a new plasmid for P. marinus that allows two proteins from a single mRNA to be differently localized using a self-cleaving 2A peptide. This enabled us to establish a stable transfectant expressing a mitochondrially targeted fluorescent protein. The system can be applied to any protein in theory and would make a powerful tool for investigating unique organelles in P. marinus and related dinoflagellates.
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Affiliation(s)
- Hirokazu Sakamoto
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan.,Department of Host-Defense Biochemistry, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Motomichi Matsuzaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,RIKEN Center for Advanced Intelligence Project, Tokyo, Japan
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35
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Garmash EV. Role of mitochondrial alternative oxidase in the regulation of cellular homeostasis during development of photosynthetic function in greening leaves. Plant Biol (Stuttg) 2021; 23:221-228. [PMID: 33190385 DOI: 10.1111/plb.13217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/08/2020] [Indexed: 05/27/2023]
Abstract
Here, recent publications on the role of mitochondrial non-phosphorylating pathways (NPhPs) in the electron transport chain during the de-etiolation of wheat leaves are reviewed. Among NPhPs, the alternative oxidase (AOX) pathway is the most effective pathway in maintaining cellular redox and energy balance, especially under stress conditions, including light stress. AOX is considered to dissipate excess reductants produced in the chloroplasts, and thereby prevent photooxidation. However, when etiolated wheat plants were exposed to a physiologically relevant light level, AOX was rapidly induced and increased, although the etioplasts did not produce excess reductants and have their own strong photoprotective mechanisms. The present study provides further insights into the role of AOX in greening cells and highlights the importance of AOX in the integration of cellular signalling pathways.
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Affiliation(s)
- E V Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, 167982, Russian Federation
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36
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Ito K, Ogata T, Seito T, Umekawa Y, Kakizaki Y, Osada H, Moore AL. Degradation of mitochondrial alternative oxidase in the appendices of Arum maculatum. Biochem J 2020; 477:3417-31. [PMID: 32856714 DOI: 10.1042/BCJ20200515] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 01/09/2023]
Abstract
Cyanide-resistant alternative oxidase (AOX) is a nuclear-encoded quinol oxidase located in the inner mitochondrial membrane. Although the quality control of AOX proteins is expected to have a role in elevated respiration in mitochondria, it remains unclear whether thermogenic plants possess molecular mechanisms for the mitochondrial degradation of AOX. To better understand the mechanism of AOX turnover in mitochondria, we performed a series of in organello AOX degradation assays using mitochondria from various stages of the appendices of Arum maculatum. Our analyses clearly indicated that AOX proteins at certain stages in the appendices are degraded at 30°C, which is close to the maximum appendix temperature observed during thermogenesis. Interestingly, such temperature-dependent protease activities were specifically inhibited by E-64, a cysteine protease inhibitor. Moreover, purification and subsequent nano LC–MS/MS analyses of E-64-sensitive and DCG-04-labeled active mitochondrial protease revealed an ∼30 kDa protein with an identical partial peptide sequence to the cysteine protease 1-like protein from Phoenix dactylifera. Our data collectively suggest that AOX is a potential target for temperature-dependent E-64-sensitive cysteine protease in the appendices of A. maculatum. A possible retrograde signalling cascade mediated by specific degradation of AOX proteins and its physiological significance are discussed.
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Hierro-Yap C, Šubrtová K, Gahura O, Panicucci B, Dewar C, Chinopoulos C, Schnaufer A, Zíková A. Bioenergetic consequences of F oF 1-ATP synthase/ATPase deficiency in two life cycle stages of Trypanosoma brucei. J Biol Chem 2021; 296:100357. [PMID: 33539923 PMCID: PMC7949148 DOI: 10.1016/j.jbc.2021.100357] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/23/2020] [Accepted: 01/28/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial ATP synthase is a reversible nanomotor synthesizing or hydrolyzing ATP depending on the potential across the membrane in which it is embedded. In the unicellular parasite Trypanosoma brucei, the direction of the complex depends on the life cycle stage of this digenetic parasite: in the midgut of the tsetse fly vector (procyclic form), the FoF1–ATP synthase generates ATP by oxidative phosphorylation, whereas in the mammalian bloodstream form, this complex hydrolyzes ATP and maintains mitochondrial membrane potential (ΔΨm). The trypanosome FoF1–ATP synthase contains numerous lineage-specific subunits whose roles remain unknown. Here, we seek to elucidate the function of the lineage-specific protein Tb1, the largest membrane-bound subunit. In procyclic form cells, Tb1 silencing resulted in a decrease of FoF1–ATP synthase monomers and dimers, rerouting of mitochondrial electron transfer to the alternative oxidase, reduced growth rate and cellular ATP levels, and elevated ΔΨm and total cellular reactive oxygen species levels. In bloodstream form parasites, RNAi silencing of Tb1 by ∼90% resulted in decreased FoF1–ATPase monomers and dimers, but it had no apparent effect on growth. The same findings were obtained by silencing of the oligomycin sensitivity-conferring protein, a conserved subunit in T. brucei FoF1–ATP synthase. However, as expected, nearly complete Tb1 or oligomycin sensitivity-conferring protein suppression was lethal because of the inability to sustain ΔΨm. The diminishment of FoF1–ATPase complexes was further accompanied by a decreased ADP/ATP ratio and reduced oxygen consumption via the alternative oxidase. Our data illuminate the often diametrically opposed bioenergetic consequences of FoF1–ATP synthase loss in insect versus mammalian forms of the parasite.
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Affiliation(s)
- Carolina Hierro-Yap
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Karolína Šubrtová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic; Institute of Immunology and Infection Research, University of Edinburgh, United Kingdom
| | - Ondřej Gahura
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Brian Panicucci
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Caroline Dewar
- Institute of Immunology and Infection Research, University of Edinburgh, United Kingdom
| | | | - Achim Schnaufer
- Institute of Immunology and Infection Research, University of Edinburgh, United Kingdom
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic.
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Granados-Arvizu JA, Canizal-García M, Madrigal-Pérez LA, González-Hernández JC, Regalado-González C. Inhibition of alternative respiration system of Scheffersomyces stipitis and effect on glucose or xylose fermentation. FEMS Yeast Res 2021; 21:6119908. [PMID: 33493281 DOI: 10.1093/femsyr/foab005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 01/22/2021] [Indexed: 11/13/2022] Open
Abstract
Scheffersomyces stipitis is a Crabtree-negative pentose fermenting yeast, which shows a complex respiratory system involving a cytochrome and an alternative salicylhydroxamic acid (SHAM)-sensitive respiration mechanism that is poorly understood. This work aimed to investigate the role of the antimycin A (AA) sensitive respiration and SHAM-sensitive respiration in the metabolism of xylose and glucose by S. stipitis, upon different agitation conditions. Inhibition of the SHAM-sensitive respiration caused a significant (P < 0.05) decrease in glycolytic flux and oxygen consumption when using glucose and xylose under agitation conditions, but without agitation, only a mild reduction was observed. The combination of SHAM and AA abolished respiration, depleting the glycolytic flux using both carbon sources tested, leading to increased ethanol production of 21.05 g/L at 250 rpm for 0.5 M glucose, and 8.3 g/L ethanol using xylose. In contrast, inhibition of only the AA-sensitive respiration, caused increased ethanol production to 30 g/L using 0.5 M glucose at 250 rpm, and 11.3 g/L from 0.5 M xylose without agitation. Results showed that ethanol production can be induced by respiration inhibition, but the active role of SHAM-sensitive respiration should be considered to investigate better conditions to increase and optimize yields.
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Affiliation(s)
- J A Granados-Arvizu
- DIPA, PROPAC. Facultad de Química, Universidad Autónoma de Querétaro, C.U. Cerro de las Campanas s/n. Col. Las Campanas, C.P. 76010 Querétaro, Qro., México
| | - M Canizal-García
- Laboratorio de Biotecnología Microbiana, Tecnológico Nacional de México/ Instituto Tecnológico Superior de Ciudad Hidalgo, Av. Ing Carlos Rojas Gutiérrez #2120, 61100 Ciudad Hidalgo, Michoacán, México
| | - L A Madrigal-Pérez
- Laboratorio de Biotecnología Microbiana, Tecnológico Nacional de México/ Instituto Tecnológico Superior de Ciudad Hidalgo, Av. Ing Carlos Rojas Gutiérrez #2120, 61100 Ciudad Hidalgo, Michoacán, México
| | - J C González-Hernández
- Laboratorio de Bioquímica, Tecnológico Nacional de México/ Instituto Tecnológico de Morelia, Av. Tecnológico de Morelia #1500, 58120 Morelia, Michoacán, México
| | - C Regalado-González
- DIPA, PROPAC. Facultad de Química, Universidad Autónoma de Querétaro, C.U. Cerro de las Campanas s/n. Col. Las Campanas, C.P. 76010 Querétaro, Qro., México
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Zafari S, Vanlerberghe GC, Igamberdiev AU. Nitric Oxide Turnover Under Hypoxia Results in the Rapid Increased Expression of the Plastid-Localized Phosphorylated Pathway of Serine Biosynthesis. Front Plant Sci 2021; 12:780842. [PMID: 35173748 PMCID: PMC8841671 DOI: 10.3389/fpls.2021.780842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/28/2021] [Indexed: 05/03/2023]
Abstract
The plant mitochondrial electron transport chain influences carbon and nitrogen metabolism under near anoxic conditions through its involvement in the phytoglobin-nitric oxide cycle, where the respiratory chain reduces nitrite to nitric oxide (NO), followed by NO conversion to nitrate by class 1 phytoglobin. Wild type (WT) and transgenic tobacco (Nicotiana tabacum L.) with differing amounts of alternative oxidase (AOX) were used to manipulate NO generation under hypoxia, and to examine whether this in turn influenced the gene expression of two stress-related amino acid biosynthetic pathways, the plastid-localized phosphorylated pathway of serine biosynthesis (PPSB), and the γ-aminobutyric acid (GABA) shunt. Under hypoxia, leaf NO emission rate was highest in AOX overexpressors and lowest in AOX knockdowns, with WT showing an intermediate rate. In turn, the rate of NO emission correlated with the degree to which amino acids accumulated. This amino acid accumulation was associated with the increased expression of the enzymes of the stress-related amino acid biosynthetic pathways. However, induction of the PPSB occurred much earlier than the GABA shunt. This work shows that high rates of NO turnover associate with rapid gene induction of the PPSB, establishing a clear link between this pathway and the maintenance of carbon, nitrogen and energy metabolism under hypoxia.
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Affiliation(s)
- Somaieh Zafari
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
- *Correspondence: Abir U. Igamberdiev,
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Cisse EHM, Miao LF, Yang F, Huang JF, Li DD, Zhang J. Gly Betaine Surpasses Melatonin to Improve Salt Tolerance in Dalbergia odorifera. Front Plant Sci 2021; 12:588847. [PMID: 33633756 PMCID: PMC7900558 DOI: 10.3389/fpls.2021.588847] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 01/19/2021] [Indexed: 05/15/2023]
Abstract
Salinity is one of the most serious factors limiting plant growth which can provoke significant losses in agricultural crop production, particularly in arid and semi-arid areas. This study aimed to investigate whether melatonin (MT; 0.05 and 0.1 mM), which has pleiotropic roles, has a better effect than glycine betaine (GB; 10 and 50 mM) on providing salt tolerance in a woody plant Dalbergia odorifera T. Chen. Also, the alternative oxidase activity (AOX) in plant subjected to MT or GB under salinity (150 and 250 mM) was evaluated given that the effect of exogenous MT or GB on AOX has not been reported yet. The results showed that the exogenous application of GB on the seedlings of D. odorifera increased the plant growth parameters, relative water content, total of chlorophyll content, and carotenoid content compared with well-watered and MT treatments. Under severe salinity, the seedlings subjected to GB showed, a significant enhancement in water use efficiency, transpiration, and net photosynthetic rate regardless to MT-treated seedlings. The levels of proline and soluble sugar in the seedlings treated with MT or GB decreased significantly under mild and severe salinity correlated with those in salt-stressed seedlings. Furthermore, GB-treated plants exhibited a significant inhibition of malondialdehyde content compared with MT-treated plants. The concentration of thiols and phenolic compounds were significantly enhanced in the leaves of seedlings treated with MT compared with those treated with GB. Under salt stress condition, GB scavenged significantly higher levels of hydrogen peroxide than MT; while under severe salinity, plants subjected to MT showed better scavenging ability for hydroxyl radicals compared with GB-treated seedlings. The results demonstrated also an enhancement of the levels of superoxide dismutase (SOD), guaiacol peroxidase, and AOX activities in seedlings treated with GB or MT compared with salt-stressed plants. The catalase activity (CAT) was increased by 0.05 mM MT and 0.1 mM GB under mild salinity. Meanwhile, the AOX activity under severe salinity was enhanced only by GB 50 mM. The findings of this study suggested that GB-treated seedlings possessed a better salt tolerance in comparison with MT-treated seedlings.
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Pierangelini M, Thiry M, Cardol P. Different levels of energetic coupling between photosynthesis and respiration do not determine the occurrence of adaptive responses of Symbiodiniaceae to global warming. New Phytol 2020; 228:855-868. [PMID: 32535971 PMCID: PMC7590187 DOI: 10.1111/nph.16738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 05/30/2020] [Indexed: 05/06/2023]
Abstract
Disentangling the metabolic functioning of corals' endosymbionts (Symbiodiniaceae) is relevant to understanding the response of coral reefs to warming oceans. In this work, we first question whether there is an energetic coupling between photosynthesis and respiration in Symbiodiniaceae (Symbiodinium, Durusdinium and Effrenium), and second, how different levels of energetic coupling will affect their adaptive responses to global warming. Coupling between photosynthesis and respiration was established by determining the variation of metabolic rates during thermal response curves, and how inhibition of respiration affects photosynthesis. Adaptive (irreversible) responses were studied by exposing two Symbiodinium species with different levels of photosynthesis-respiration interaction to high temperature conditions (32°C) for 1 yr. We found that some Symbiodiniaceae have a high level of energetic coupling; that is, photosynthesis and respiration have the same temperature dependency, and photosynthesis is negatively affected when respiration is inhibited. Conversely, photosynthesis and respiration are not coupled in other species. In any case, prolonged exposure to high temperature caused adjustments in both photosynthesis and respiration, but these changes were fully reversible. We conclude that energetic coupling between photosynthesis and respiration exhibits wide variation amongst Symbiodiniaceae and does not determine the occurrence of adaptive responses in Symbiodiniaceae to temperature increase.
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Affiliation(s)
- Mattia Pierangelini
- Génétique et Physiologie des MicroalguesInBioS/PhytosystemsInstitut de BotaniqueUniversité de LiègeB22Liège4000Belgium
| | - Marc Thiry
- Unit of Cell BiologyGIGA‐NeurosciencesCHU Sart‐TilmanUniversity of LiègeLiègeB36, 4000Belgium
| | - Pierre Cardol
- Génétique et Physiologie des MicroalguesInBioS/PhytosystemsInstitut de BotaniqueUniversité de LiègeB22Liège4000Belgium
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Ma Q, Liu Y, Fang H, Wang P, Ahammed GJ, Zai W, Shi K. An Essential Role of Mitochondrial α-Ketoglutarate Dehydrogenase E2 in the Basal Immune Response Against Bacterial Pathogens in Tomato. Front Plant Sci 2020; 11:579772. [PMID: 33193523 PMCID: PMC7661389 DOI: 10.3389/fpls.2020.579772] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/18/2020] [Indexed: 06/01/2023]
Abstract
Plants intensely modulate respiration when pathogens attack, but the function of mitochondrial respiration-related genes in plant-bacteria interaction is largely unclear. Here, the functions of α-ketoglutarate dehydrogenase (α-kGDH) E2 subunit and alternative oxidase (AOX) were investigated in the interaction between tomato and the virulent bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pst). Pst inoculation suppressed the transcript abundance of α-kGDH E2, but enhanced AOX expression and salicylic acid (SA) accumulation. Gene silencing and transient overexpression approaches revealed that plant susceptibility to Pst was significantly reduced by silencing α-kGDH E2 in tomato, but increased by overexpressing α-kGDH E2 in Nicotiana benthamiana, whereas silencing or overexpressing of AOX1a did not affect plant defense. Moreover, silencing octanoyltransferase (LIP2), engaged in the lipoylation of α-kGDH E2, significantly reduced disease susceptibility and hydrogen peroxide accumulation. Use of transgenic NahG tomato plants that cannot accumulate SA as well as the exogenous SA application experiment evidenced that α-kGDH E2 acts downstream of SA defense pathway. These results demonstrate tomato α-kGDH E2 plays a negative role in plant basal defense against Pst in an AOX-independent pathway but was associated with lipoylation and SA defense pathways. The findings help to elucidate the mechanisms of mitochondria-involved plant basal immunity.
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Affiliation(s)
- Qiaomei Ma
- Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Yaru Liu
- Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Hanmo Fang
- Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Ping Wang
- Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Golam Jalal Ahammed
- College of Forestry, Henan University of Science and Technology, Luoyang, China
| | - Wenshan Zai
- Wenzhou Vocational College of Science & Technology, Wenzhou, China
| | - Kai Shi
- Department of Horticulture, Zhejiang University, Hangzhou, China
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Hewitt S, Dhingra A. Beyond Ethylene: New Insights Regarding the Role of Alternative Oxidase in the Respiratory Climacteric. Front Plant Sci 2020; 11:543958. [PMID: 33193478 PMCID: PMC7652990 DOI: 10.3389/fpls.2020.543958] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 09/24/2020] [Indexed: 06/11/2023]
Abstract
Climacteric fruits are characterized by a dramatic increase in autocatalytic ethylene production that is accompanied by a spike in respiration at the onset of ripening. The change in the mode of ethylene production from autoinhibitory to autostimulatory is known as the System 1 (S1) to System 2 (S2) transition. Existing physiological models explain the basic and overarching genetic, hormonal, and transcriptional regulatory mechanisms governing the S1 to S2 transition of climacteric fruit. However, the links between ethylene and respiration, the two main factors that characterize the respiratory climacteric, have not been examined in detail at the molecular level. Results of recent studies indicate that the alternative oxidase (AOX) respiratory pathway may play an essential role in mediating cross-talk between ethylene response, carbon metabolism, ATP production, and ROS signaling during climacteric ripening. New genomic, metabolic, and epigenetic information sheds light on the interconnectedness of ripening metabolic pathways, necessitating an expansion of the current, ethylene-centric physiological models. Understanding points at which ripening responses can be manipulated may reveal key, species- and cultivar-specific targets for regulation of ripening, enabling superior strategies for reducing postharvest wastage.
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Affiliation(s)
- Seanna Hewitt
- Molecular Plant Sciences Program, Washington State University, Pullman, WA, United States
- Department of Horticulture, Washington State University, Pullman, WA, United States
| | - Amit Dhingra
- Molecular Plant Sciences Program, Washington State University, Pullman, WA, United States
- Department of Horticulture, Washington State University, Pullman, WA, United States
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Chadee A, Vanlerberghe GC. Distinctive mitochondrial and chloroplast components contributing to the maintenance of carbon balance during plant growth at elevated CO 2. Plant Signal Behav 2020; 15:1795395. [PMID: 32705929 PMCID: PMC8550537 DOI: 10.1080/15592324.2020.1795395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Plant carbon balance depends upon the difference between photosynthetic carbon gain and respiratory carbon loss. In C3 plants, growth at an elevated atmospheric concentration of CO2 (ECO2) stimulates photosynthesis and raises the leaf carbohydrate status, but how respiration responds is less understood. In this study, growth of Nicotiana tabacum at ECO2 increased the protein amount of the non-energy conserving mitochondrial alternative oxidase (AOX). Growth at ECO2 increased AOX1a transcript amount, and the transcript amount of a putative sugar-responsive gene encoding a chloroplast glucose-6-phosphate/phosphate translocator (GPT3). We suggest that the elevated amounts of AOX and GPT3 represent distinctive mitochondrial and chloroplast mechanisms to manage an excessive cytosolic pool of sugar phosphates. AOX respiration could consume cytosolic sugar phosphates, without this activity being restricted by rates of ATP turnover. GPT3 could allow accumulating cytosolic glucose-6-phosphate to return to the chloroplast. This could feed starch synthesis or a glucose-6-phosphate shunt in the Calvin cycle. AOX and GPT3 activities could buffer against Pi depletions that might otherwise disrupt mitochondrial and chloroplast electron transport chain activities. AOX and GPT3 activities could also buffer against a down-regulation of photosynthetic capacity by preventing a persistent imbalance between photosynthetic carbon gain and the activity of carbon utilizing sinks.
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Affiliation(s)
- Avesh Chadee
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
- CONTACT Greg C. Vanlerberghe Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ONM1C1A4, Canada
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Weaver RJ, Carrion G, Nix R, Maeda GP, Rabinowitz S, Iverson ENK, Thueson K, Havird JC. High mitochondrial mutation rates in Silene are associated with nuclear-mediated changes in mitochondrial physiology. Biol Lett 2020; 16:20200450. [PMID: 32933406 DOI: 10.1098/rsbl.2020.0450] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial (mt) respiration depends on proteins encoded both by the mitochondrial and nuclear genomes. Variation in mt-DNA mutation rates exists across eukaryotes, although the functional consequences of elevated mt mutation rates in some lineages remain underexplored. In the angiosperm genus Silene, closely related, ecologically similar species have either 'fast' or 'slow' mt-DNA mutation rates. Here, we investigated the functional consequences of elevated mt-DNA mutation rates on mt respiration profiles of Silene mitochondria. Overall levels of respiration were similar among Species. Fast species had lower respiration efficiency than slow species and relied up to 48% more on nuclear-encoded respiratory enzymes alternative oxidase (AOX) and accessory dehydrogenases (DHex), which participate in stress responses in plants. However, not all fast species showed these trends. Respiratory profiles of some enzymes were correlated, most notably AOX and DHex. We conclude that subtle differences in mt physiology among Silene lineages with dramatically different mt mutation rates may underly similar phenotypes at higher levels of biological organization, betraying the consequences of mt mutations.
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Affiliation(s)
- Ryan J Weaver
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Gina Carrion
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Rachel Nix
- Hankamer School of Business, Baylor University, Waco, TX 76798, USA
| | - Gerald P Maeda
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Samantha Rabinowitz
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Erik N K Iverson
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Kiley Thueson
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Justin C Havird
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
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Desaulniers AB, Kishore N, Adames K, Nargang FE. Characterization of Single Gene Deletion Mutants Affecting Alternative Oxidase Production in Neurospora crassa: Role of the yvh1 Gene. Microorganisms 2020; 8:E1186. [PMID: 32759834 DOI: 10.3390/microorganisms8081186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/29/2020] [Accepted: 07/31/2020] [Indexed: 01/21/2023] Open
Abstract
The Neurospora crassa AOD1 protein is a mitochondrial alternative oxidase that passes electrons directly from ubiquinol to oxygen. The enzyme is encoded by the nuclear aod-1 gene and is produced when the standard electron transport chain is inhibited. We previously identified eleven strains in the N. crassa single gene deletion library that were severely deficient in their ability to produce AOD1 when grown in the presence of chloramphenicol, an inhibitor of mitochondrial translation that is known to induce the enzyme. Three mutants affected previously characterized genes. In this report we examined the remaining mutants and found that the deficiency of AOD1 was due to secondary mutations in all but two of the strains. One of the authentic mutants contained a deletion of the yvh1 gene and was found to have a deficiency of aod-1 transcripts. The YVH1 protein localized to the nucleus and a post mitochondrial pellet from the cytoplasm. A zinc binding domain in the protein was required for rescue of the AOD1 deficiency. In other organisms YVH1 is required for ribosome assembly and mutants have multiple phenotypes. Lack of YVH1 in N. crassa likely also affects ribosome assembly leading to phenotypes that include altered regulation of AOD1 production.
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Adamowicz-Skrzypkowska A, Kwasniak-Owczarek M, Van Aken O, Kazmierczak U, Janska H. Joint inhibition of mitochondrial complex IV and alternative oxidase by genetic or chemical means represses chloroplast transcription in Arabidopsis. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190409. [PMID: 32362248 PMCID: PMC7209957 DOI: 10.1098/rstb.2019.0409] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2020] [Indexed: 12/14/2022] Open
Abstract
Changes in the functional state of mitochondria have profound effects on other cellular compartments. Genome-wide expression analysis of Arabidopsisrps10 mutants with an RNAi-silenced expression of mitoribosomal S10 protein has revealed extensive transcriptional reprogramming. A meta-analysis comparing expression datasets of 25 mitochondrial perturbations showed a high similarity of the aox1a:rpoTmp mutant, which is defective in the alternative oxidase (AOX1a) and dual-targeted mitochondrial and plastid RNA polymerase (RPOTmp), to rps10. Both rps10 and aox1a:rpoTmp showed a significantly decreased electron flux through both the cytochrome and the alternative respiratory pathways, and a markedly decreased the expression of nuclear-encoded components of the chloroplast transcription machinery. In line with this, a decreased level of plastid transcripts was observed in rps10 and aox1a:rpoTmp, which was reflected in a reduced rate of chloroplast transcription. Chemical treatment of wild-type seedlings with respiratory inhibitors showed that only simultaneous and direct inhibition of complex IV and AOX activity decreased the level of plastid transcripts. Taken together, both chemical and genetic studies show that the limitation of the activity of two mitochondrial terminal oxidases, complex IV and AOX, negatively impacts chloroplast transcription. Salicylic acid and oxygen are discussed as putative mediators of the signalling pathway between mitochondria, nucleus and chloroplasts. This article is part of the theme issue 'Retrograde signalling from endosymbiotic organelles'.
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Affiliation(s)
| | | | - Olivier Van Aken
- Department of Biology, Lund University, Sölvegatan 35, 223 62 Lund, Sweden
| | - Urszula Kazmierczak
- Faculty of Biotechnology, University of Wroclaw, F. Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Hanna Janska
- Faculty of Biotechnology, University of Wroclaw, F. Joliot-Curie 14a, 50-383 Wroclaw, Poland
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Abstract
Adenosine triphosphate (ATP), the cellular energy currency, is essential for life. The ability to provide a constant supply of ATP is therefore crucial for the construction of artificial cells in synthetic biology. Here, we describe the bottom-up assembly and characterization of a minimal respiratory system that uses NADH as a fuel to produce ATP from ADP and inorganic phosphate, and is thus capable of sustaining both upstream metabolic processes that rely on NAD+, and downstream energy-demanding processes that are powered by ATP hydrolysis. A detergent-mediated approach was used to co-reconstitute respiratory mitochondrial complex I and an F-type ATP synthase into nanosized liposomes. Addition of the alternative oxidase to the resulting proteoliposomes produced a minimal artificial "organelle" that reproduces the energy-converting catalytic reactions of the mitochondrial respiratory chain: NADH oxidation, ubiquinone cycling, oxygen reduction, proton pumping, and ATP synthesis. As a proof-of-principle, we demonstrate that our nanovesicles are capable of using an NAD+-linked substrate to drive cell-free protein expression. Our nanovesicles are both efficient and durable and may be applied to sustain artificial cells in future work.
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Affiliation(s)
- Olivier Biner
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
| | - Justin G Fedor
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
| | - Zhan Yin
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
| | - Judy Hirst
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
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Ortíz J, Sanhueza C, Romero-Munar A, Hidalgo-Castellanos J, Castro C, Bascuñán-Godoy L, Coba de la Peña T, López-Gómez M, Florez-Sarasa I, Del-Saz NF. In Vivo Metabolic Regulation of Alternative Oxidase under Nutrient Deficiency-Interaction with Arbuscular Mycorrhizal Fungi and Rhizobium Bacteria. Int J Mol Sci 2020; 21:E4201. [PMID: 32545597 PMCID: PMC7349880 DOI: 10.3390/ijms21124201] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/05/2020] [Accepted: 06/10/2020] [Indexed: 02/02/2023] Open
Abstract
The interaction of the alternative oxidase (AOX) pathway with nutrient metabolism is important for understanding how respiration modulates ATP synthesis and carbon economy in plants under nutrient deficiency. Although AOX activity reduces the energy yield of respiration, this enzymatic activity is upregulated under stress conditions to maintain the functioning of primary metabolism. The in vivo metabolic regulation of AOX activity by phosphorus (P) and nitrogen (N) and during plant symbioses with Arbuscular mycorrhizal fungi (AMF) and Rhizobium bacteria is still not fully understood. We highlight several findings and open questions concerning the in vivo regulation of AOX activity and its impact on plant metabolism during P deficiency and symbiosis with AMF. We also highlight the need for the identification of which metabolic regulatory factors of AOX activity are related to N availability and nitrogen-fixing legume-rhizobia symbiosis in order to improve our understanding of N assimilation and biological nitrogen fixation.
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Affiliation(s)
- José Ortíz
- Laboratorio de Fisiología Vegetal, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, 4030000 Concepción, Chile; (J.O.); (C.S.); (C.C.); (L.B.-G.)
| | - Carolina Sanhueza
- Laboratorio de Fisiología Vegetal, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, 4030000 Concepción, Chile; (J.O.); (C.S.); (C.C.); (L.B.-G.)
| | - Antònia Romero-Munar
- Centro de Estudios Avanzados en Fruticultura (CEAF), Camino Las Parcelas 882, km 105 Ruta 5 Sur. Sector los Choapinos, 2940000 Rengo, Chile;
| | - Javier Hidalgo-Castellanos
- Department of Plant Physiology, Faculty of sciences, University of Granada, 18071 Granada, Spain; (J.H.-C.); (M.L.-G.)
| | - Catalina Castro
- Laboratorio de Fisiología Vegetal, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, 4030000 Concepción, Chile; (J.O.); (C.S.); (C.C.); (L.B.-G.)
| | - Luisa Bascuñán-Godoy
- Laboratorio de Fisiología Vegetal, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, 4030000 Concepción, Chile; (J.O.); (C.S.); (C.C.); (L.B.-G.)
| | | | - Miguel López-Gómez
- Department of Plant Physiology, Faculty of sciences, University of Granada, 18071 Granada, Spain; (J.H.-C.); (M.L.-G.)
| | - Igor Florez-Sarasa
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain;
| | - Néstor Fernández Del-Saz
- Laboratorio de Fisiología Vegetal, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, 4030000 Concepción, Chile; (J.O.); (C.S.); (C.C.); (L.B.-G.)
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Horianopoulos LC, Hu G, Caza M, Schmitt K, Overby P, Johnson JD, Valerius O, Braus GH, Kronstad JW. The Novel J-Domain Protein Mrj1 Is Required for Mitochondrial Respiration and Virulence in Cryptococcus neoformans. mBio 2020; 11:e01127-20. [PMID: 32518190 DOI: 10.1128/mBio.01127-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cryptococcus neoformans is the causative agent of cryptococcal meningitis, a disease responsible for ∼15% of all HIV-related deaths. Unfortunately, development of antifungal drugs is challenging because potential targets are conserved between humans and C. neoformans. In this context, we characterized a unique J-domain protein, Mrj1, which lacks orthologs in humans. We showed that Mrj1 was required for normal mitochondrial respiration and that mutants lacking Mrj1 were deficient in growth, capsule elaboration, and virulence. Furthermore, we were able to phenocopy the defects in growth and capsule elaboration by inhibiting respiration. This result suggests that the role of Mrj1 in mitochondrial function was responsible for the observed virulence defects and reinforces the importance of mitochondria to fungal pathogenesis. Mitochondria are difficult to target, as their function is also key to human cells; however, Mrj1 presents an opportunity to target a unique fungal protein required for mitochondrial function and virulence in C. neoformans. The opportunistic fungal pathogen Cryptococcus neoformans must adapt to the mammalian environment to establish an infection. Proteins facilitating adaptation to novel environments, such as chaperones, may be required for virulence. In this study, we identified a novel mitochondrial co-chaperone, Mrj1 (mitochondrial respiration J-domain protein 1), necessary for virulence in C. neoformans. The mrj1Δ and J-domain-inactivated mutants had general growth defects at both routine laboratory and human body temperatures and were deficient in the major virulence factor of capsule elaboration. The latter phenotype was associated with cell wall changes and increased capsular polysaccharide shedding. Accordingly, the mrj1Δ mutant was avirulent in a murine model of cryptococcosis. Mrj1 has a mitochondrial localization and co-immunoprecipitated with Qcr2, a core component of complex III of the electron transport chain. The mrj1 mutants were deficient in mitochondrial functions, including growth on alternative carbon sources, growth without iron, and mitochondrial polarization. They were also insensitive to complex III inhibitors and hypersensitive to an alternative oxidase (AOX) inhibitor, suggesting that Mrj1 functions in respiration. In support of this conclusion, mrj1 mutants also had elevated basal oxygen consumption rates which were completely abolished by the addition of the AOX inhibitor, confirming that Mrj1 is required for mitochondrial respiration through complexes III and IV. Furthermore, inhibition of complex III phenocopied the capsule and cell wall defects of the mrj1 mutants. Taken together, these results indicate that Mrj1 is required for normal mitochondrial respiration, a key aspect of adaptation to the host environment and virulence.
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