1
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Kuo WH, Small LL, Olsen KM. Variable expression of cyanide detoxification and tolerance genes in cyanogenic and acyanogenic white clover (Trifolium repens). AMERICAN JOURNAL OF BOTANY 2023; 110:e16233. [PMID: 37661820 DOI: 10.1002/ajb2.16233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/04/2023] [Accepted: 08/04/2023] [Indexed: 09/05/2023]
Abstract
PREMISE β-Cyanoalanine synthase (β-CAS) and alternative oxidase (AOX) play important roles in the ability of plants to detoxify and tolerate hydrogen cyanide (HCN). These functions are critical for all plants because HCN is produced at low levels during basic metabolic processes, and especially for cyanogenic species, which release high levels of HCN following tissue damage. However, expression of β-CAS and Aox genes has not been examined in cyanogenic species, nor compared between cyanogenic and acyanogenic genotypes within a species. METHODS We used a natural polymorphism for cyanogenesis in white clover to examine β-CAS and Aox gene expression in relation to cyanogenesis-associated HCN exposure. We identified all β-CAS and Aox gene copies present in the genome, including members of the Aox1, Aox2a, and Aox2d subfamilies previously reported in legumes. Expression levels were compared between cyanogenic and acyanogenic genotypes and between damaged and undamaged leaf tissue. RESULTS β-CAS and Aox2a expression was differentially elevated in cyanogenic genotypes, and tissue damage was not required to induce this increased expression. Aox2d, in contrast, appeared to be upregulated as a generalized wounding response. CONCLUSIONS These findings suggest a heightened constitutive role for HCN detoxification (via elevated β-CAS expression) and HCN-toxicity mitigation (via elevated Aox2a expression) in plants that are capable of cyanogenesis. As such, freezing-induced cyanide autotoxicity is unlikely to be the primary selective factor in the evolution of climate-associated cyanogenesis clines.
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Affiliation(s)
- Wen-Hsi Kuo
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Linda L Small
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Kenneth M Olsen
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
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2
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Ding Y, Fan B, Zhu C, Chen Z. Shared and Related Molecular Targets and Actions of Salicylic Acid in Plants and Humans. Cells 2023; 12:cells12020219. [PMID: 36672154 PMCID: PMC9856608 DOI: 10.3390/cells12020219] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/29/2022] [Accepted: 01/01/2023] [Indexed: 01/06/2023] Open
Abstract
Salicylic acid (SA) is a phenolic compound produced by all plants that has an important role in diverse processes of plant growth and stress responses. SA is also the principal metabolite of aspirin and is responsible for many of the anti-inflammatory, cardioprotective and antitumor activities of aspirin. As a result, the number of identified SA targets in both plants and humans is large and continues to increase. These SA targets include catalases/peroxidases, metabolic enzymes, protein kinases and phosphatases, nucleosomal and ribosomal proteins and regulatory and signaling proteins, which mediate the diverse actions of SA in plants and humans. While some of these SA targets and actions are unique to plants or humans, many others are conserved or share striking similarities in the two types of organisms, which underlie a host of common biological processes that are regulated or impacted by SA. In this review, we compare shared and related SA targets and activities to highlight the common nature of actions by SA as a hormone in plants versus a therapeutic agent in humans. The cross examination of SA targets and activities can help identify new actions of SA and better explain their underlying mechanisms in plants and humans.
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Affiliation(s)
- Yuanyuan Ding
- College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Baofang Fan
- Department of Botany and Plant Pathology and Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907-2054, USA
| | - Cheng Zhu
- College of Life Sciences, China Jiliang University, Hangzhou 310018, China
- Correspondence: (C.Z.); (Z.C.); Tel.: +86-571-8683-6090 (C.Z.); +1-765-494-4657 (Z.C.)
| | - Zhixiang Chen
- College of Life Sciences, China Jiliang University, Hangzhou 310018, China
- Department of Botany and Plant Pathology and Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907-2054, USA
- Correspondence: (C.Z.); (Z.C.); Tel.: +86-571-8683-6090 (C.Z.); +1-765-494-4657 (Z.C.)
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3
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Garcia A, Gaju O, Bowerman AF, Buck SA, Evans JR, Furbank RT, Gilliham M, Millar AH, Pogson BJ, Reynolds MP, Ruan Y, Taylor NL, Tyerman SD, Atkin OK. Enhancing crop yields through improvements in the efficiency of photosynthesis and respiration. THE NEW PHYTOLOGIST 2023; 237:60-77. [PMID: 36251512 PMCID: PMC10100352 DOI: 10.1111/nph.18545] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/15/2022] [Indexed: 06/06/2023]
Abstract
The rate with which crop yields per hectare increase each year is plateauing at the same time that human population growth and other factors increase food demand. Increasing yield potential (Y p ) of crops is vital to address these challenges. In this review, we explore a component ofY p that has yet to be optimised - that being improvements in the efficiency with which light energy is converted into biomass (ε c ) via modifications to CO2 fixed per unit quantum of light (α), efficiency of respiratory ATP production (ε prod ) and efficiency of ATP use (ε use ). For α, targets include changes in photoprotective machinery, ribulose bisphosphate carboxylase/oxygenase kinetics and photorespiratory pathways. There is also potential forε prod to be increased via targeted changes to the expression of the alternative oxidase and mitochondrial uncoupling pathways. Similarly, there are possibilities to improveε use via changes to the ATP costs of phloem loading, nutrient uptake, futile cycles and/or protein/membrane turnover. Recently developed high-throughput measurements of respiration can serve as a proxy for the cumulative energy cost of these processes. There are thus exciting opportunities to use our growing knowledge of factors influencing the efficiency of photosynthesis and respiration to create a step-change in yield potential of globally important crops.
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Affiliation(s)
- Andres Garcia
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - Oorbessy Gaju
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- College of Science, Lincoln Institute for Agri‐Food TechnologyUniversity of LincolnLincolnshireLN2 2LGUK
| | - Andrew F. Bowerman
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - Sally A. Buck
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - John R. Evans
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
- ARC Centre of Excellence for Translational Photosynthesis, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
| | - Robert T. Furbank
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
- ARC Centre of Excellence for Translational Photosynthesis, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
| | - Matthew Gilliham
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine & Waite Research InstituteUniversity of AdelaideGlen OsmondSA5064Australia
| | - A. Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences & Institute of AgricultureThe University of Western AustraliaCrawleyWA6009Australia
| | - Barry J. Pogson
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - Matthew P. Reynolds
- International Maize and Wheat Improvement Center (CIMMYT)Km. 45, Carretera Mexico, El BatanTexcoco56237Mexico
| | - Yong‐Ling Ruan
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - Nicolas L. Taylor
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences & Institute of AgricultureThe University of Western AustraliaCrawleyWA6009Australia
| | - Stephen D. Tyerman
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine & Waite Research InstituteUniversity of AdelaideGlen OsmondSA5064Australia
| | - Owen K. Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
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4
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Wang X, Geng X, Bi X, Li R, Chen Y, Lu C. Genome-wide identification of AOX family genes in Moso bamboo and functional analysis of PeAOX1b_2 in drought and salinity stress tolerance. PLANT CELL REPORTS 2022; 41:2321-2339. [PMID: 36063182 DOI: 10.1007/s00299-022-02923-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
Five PeAOX genes from Moso bamboo genome were identified. PeAOX1b_2-OE improved tolerance to drought and salinity stress in Arabidopsis, indicating it is involved in positive regulation of abiotic stress response. Mitochondrial alternative oxidase (AOX), the important respiratory terminal oxidase in organisms, catalyzes the energy wasteful cyanide (CN)-resistant respiration, which can improve abiotic stresses tolerance and is considered as one of the functional markers for plant resistance breeding. Here, a total of five putative AOX genes (PeAOXs) were identified and characterized in a monocotyledonous woody grass Moso bamboo (Phyllostachys edulis). Phylogenetic analysis revealed that PeAOXs belonged to AOX1 subfamily, and were named PeAOX1a_1, PeAOX1a_2, PeAOX1b_1, PeAOX1b_2 and PeAOX1c, respectively. Evolutionary and divergence patterns analysis revealed that the PeAOX, OsAOX, and BdAOX families experienced positive purifying selection and may have undergone a large-scale duplication event roughly 1.35-155.90 million years ago. Additionally, the organ-specific expression analysis showed that 80% of PeAOX members were mainly expressed in leaf. Promoter sequence analysis of PeAOXs revealed cis-acting regulatory elements (CAREs) responding to abiotic stress. Most PeAOX genes were significantly upregulated after methyl jasmonate (MeJA) and abscisic acid (ABA) treatment. Moreover, under salinity and drought stresses, the ectopic overexpression of PeAOX1b_2 in Arabidopsis enhanced seed germination and seedling establishment, increased the total respiratory rate and the proportion of AOX respiratory pathway in leaf, and enhanced antioxidant ability, suggesting that PeAOX1b_2 is crucial for abiotic stress resistance in Moso bamboo.
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Affiliation(s)
- Xiaojing Wang
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China
| | - Xin Geng
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China
| | - Xiaorui Bi
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China
| | - Rongchen Li
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China
| | - Yuzhen Chen
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.
| | - Cunfu Lu
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.
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Khan K, Van Aken O. The colonization of land was a likely driving force for the evolution of mitochondrial retrograde signalling in plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:7182-7197. [PMID: 36055768 PMCID: PMC9675596 DOI: 10.1093/jxb/erac351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
Most retrograde signalling research in plants was performed using Arabidopsis, so an evolutionary perspective on mitochondrial retrograde regulation (MRR) is largely missing. Here, we used phylogenetics to track the evolutionary origins of factors involved in plant MRR. In all cases, the gene families can be traced to ancestral green algae or earlier. However, the specific subfamilies containing factors involved in plant MRR in many cases arose during the transition to land. NAC transcription factors with C-terminal transmembrane domains, as observed in the key regulator ANAC017, can first be observed in non-vascular mosses, and close homologs to ANAC017 can be found in seed plants. Cyclin-dependent kinases (CDKs) are common to eukaryotes, but E-type CDKs that control MRR also diverged in conjunction with plant colonization of land. AtWRKY15 can be traced to the earliest land plants, while AtWRKY40 only arose in angiosperms and AtWRKY63 even more recently in Brassicaceae. Apetala 2 (AP2) transcription factors are traceable to algae, but the ABI4 type again only appeared in seed plants. This strongly suggests that the transition to land was a major driver for developing plant MRR pathways, while additional fine-tuning events have appeared in seed plants or later. Finally, we discuss how MRR may have contributed to meeting the specific challenges that early land plants faced during terrestrialization.
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Affiliation(s)
- Kasim Khan
- Department of Biology, Lund University, Lund, Sweden
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6
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Degradation of mitochondrial alternative oxidase in the appendices of Arum maculatum. Biochem J 2021; 477:3417-3431. [PMID: 32856714 PMCID: PMC7505559 DOI: 10.1042/bcj20200515] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [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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7
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Wang Y, Selinski J, Mao C, Zhu Y, Berkowitz O, Whelan J. Linking mitochondrial and chloroplast retrograde signalling in plants. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190410. [PMID: 32362265 PMCID: PMC7209950 DOI: 10.1098/rstb.2019.0410] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Retrograde signalling refers to the regulation of nuclear gene expression in response to functional changes in organelles. In plants, the two energy-converting organelles, mitochondria and chloroplasts, are tightly coordinated to balance their activities. Although our understanding of components involved in retrograde signalling has greatly increased in the last decade, studies on the regulation of the two organelle signalling pathways have been largely independent. Thus, the mechanism of how mitochondrial and chloroplastic retrograde signals are integrated is largely unknown. Here, we summarize recent findings on the function of mitochondrial signalling components and their links to chloroplast retrograde responses. From this, a picture emerges showing that the major regulators are integrators of both organellar retrograde signalling pathways. This article is part of the theme issue 'Retrograde signalling from endosymbiotic organelles'.
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Affiliation(s)
- Yan Wang
- Department of Animal, Plant and Soil Sciences, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - Jennifer Selinski
- Department of Animal, Plant and Soil Sciences, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - Chunli Mao
- Department of Animal, Plant and Soil Sciences, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia.,Department of Animal Science and Technology, Grassland Science, China Agricultural University, Beijing 100193, People's Republic of China
| | - Yanqiao Zhu
- Department of Animal, Plant and Soil Sciences, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia.,Department of Animal Science and Technology, Grassland Science, China Agricultural University, Beijing 100193, People's Republic of China
| | - Oliver Berkowitz
- Department of Animal, Plant and Soil Sciences, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - James Whelan
- Department of Animal, Plant and Soil Sciences, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
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8
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Poór P. Effects of Salicylic Acid on the Metabolism of Mitochondrial Reactive Oxygen Species in Plants. Biomolecules 2020; 10:E341. [PMID: 32098073 PMCID: PMC7072379 DOI: 10.3390/biom10020341] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/11/2020] [Accepted: 02/18/2020] [Indexed: 01/16/2023] Open
Abstract
Different abiotic and biotic stresses lead to the production and accumulation of reactive oxygen species (ROS) in various cell organelles such as in mitochondria, resulting in oxidative stress, inducing defense responses or programmed cell death (PCD) in plants. In response to oxidative stress, cells activate various cytoprotective responses, enhancing the antioxidant system, increasing the activity of alternative oxidase and degrading the oxidized proteins. Oxidative stress responses are orchestrated by several phytohormones such as salicylic acid (SA). The biomolecule SA is a key regulator in mitochondria-mediated defense signaling and PCD, but the mode of its action is not known in full detail. In this review, the current knowledge on the multifaceted role of SA in mitochondrial ROS metabolism is summarized to gain a better understanding of SA-regulated processes at the subcellular level in plant defense responses.
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Affiliation(s)
- Péter Poór
- Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary
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9
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Czobor Á, Hajdinák P, Németh B, Piros B, Németh Á, Szarka A. Comparison of the response of alternative oxidase and uncoupling proteins to bacterial elicitor induced oxidative burst. PLoS One 2019; 14:e0210592. [PMID: 30629714 PMCID: PMC6328269 DOI: 10.1371/journal.pone.0210592] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/25/2018] [Indexed: 12/03/2022] Open
Abstract
Plant UCPs are proved to take part in the fine-tuning of mitochondrial ROS generation. It has emerged that mitochondrion can be an important early source of intracellular ROS during plant-pathogen interaction thus plant UCPs must also play key role in this redox fine-tuning during the early phase of plant-pathogen interaction. On the contrary of this well-established assumption, the expression of plant UCPs and their activity has not been investigated in elicitor induced oxidative burst. Thus, the level of plant UCPs both at RNA and protein level and their activity was investigated and compared to AOX as a reference in Arabidopsis thaliana cells due to bacterial harpin treatments. Similar to the expression and activity of AOX, the transcript level of UCP4, UCP5 and the UCP activity increased due to harpin treatment and the consequential oxidative burst. The expression of UCP4 and UCP5 elevated 15-18-fold after 1 h of treatment, then the activity of UCP reached its maximal value at 4h of treatment. The quite rapid activation of UCP due to harpin treatment gives another possibility to fine tune the redox balance of plant cell, furthermore explains the earlier observed rapid decrease of mitochondrial membrane potential and consequent decrease of ATP synthesis after harpin treatment.
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Affiliation(s)
- Ádám Czobor
- Department of Applied Biotechnology and Food Science, Laboratory of Biochemistry and Molecular Biology, Budapest University of Technology and Economics, Budapest, Hungary
| | - Péter Hajdinák
- Department of Applied Biotechnology and Food Science, Laboratory of Biochemistry and Molecular Biology, Budapest University of Technology and Economics, Budapest, Hungary
| | - Bence Németh
- Department of Applied Biotechnology and Food Science, Laboratory of Biochemistry and Molecular Biology, Budapest University of Technology and Economics, Budapest, Hungary
| | - Borbála Piros
- Department of Applied Biotechnology and Food Science, Laboratory of Biochemistry and Molecular Biology, Budapest University of Technology and Economics, Budapest, Hungary
| | - Áron Németh
- Department of Applied Biotechnology and Food Science, Fermentation Pilot Plant Laboratory, Budapest University of Technology and Economics, Budapest, Hungary
| | - András Szarka
- Department of Applied Biotechnology and Food Science, Laboratory of Biochemistry and Molecular Biology, Budapest University of Technology and Economics, Budapest, Hungary
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Liu M, Guo X. A novel and stress adaptive alternative oxidase derived from alternative splicing of duplicated exon in oyster Crassostrea virginica. Sci Rep 2017; 7:10785. [PMID: 28883650 PMCID: PMC5589949 DOI: 10.1038/s41598-017-10976-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/17/2017] [Indexed: 12/25/2022] Open
Abstract
Alternative oxidase (AOX) is a mitochondrial inner-membrane oxidase that accepts electrons directly from ubiquinol and reduces oxygen to water without involving cytochrome-linked electron transport chain. It is highly conserved in many non-vertebrate taxa and may protect cells against hypoxia and oxidative stress. We identified two AOX mRNAs in eastern oyster Crassostrea virginica, CvAOXA and CvAOXB, which differ by 170 bp but encode AOXs of the same size. Sequence analyses indicate that CvAOX has 10 exons with a tandem duplication of exon 10, and 3' alternative splicing using either the first or second exon 10 produces the two variants CvAOXB or CvAOXA, respectively. The second exon 10 in CvAOXA is more conserved across taxa, while the first exon 10 in CvAOXB contains novel mutations surrounding key functional sites. Both variants are expressed in all organs with the expression of CvAOXA higher than that of CvAOXB under normal condition. Under stress by air exposure, CvAOXB showed significantly higher expression than CvAOXA and became the dominant variant. This is the first case of alternative splicing of duplicated exon in a mollusc that produces a novel variant adaptive to stress, highlighting genome's versatility in generating diversity and phenotypic plasticity.
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Affiliation(s)
- Ming Liu
- Haskin Shellfish Research Laboratory, Department of Marine and Coastal Sciences, Rutgers University, 6959 Miller Avenue, Port Norris, NJ, 08349, USA
| | - Ximing Guo
- Haskin Shellfish Research Laboratory, Department of Marine and Coastal Sciences, Rutgers University, 6959 Miller Avenue, Port Norris, NJ, 08349, USA.
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11
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Araújo Castro J, Gomes Ferreira MD, Santana Silva RJ, Andrade BS, Micheli F. Alternative oxidase (AOX) constitutes a small family of proteins in Citrus clementina and Citrus sinensis L. Osb. PLoS One 2017; 12:e0176878. [PMID: 28459876 PMCID: PMC5411082 DOI: 10.1371/journal.pone.0176878] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/18/2017] [Indexed: 11/18/2022] Open
Abstract
The alternative oxidase (AOX) protein is present in plants, fungi, protozoa and some invertebrates. It is involved in the mitochondrial respiratory chain, providing an alternative route for the transport of electrons, leading to the reduction of oxygen to form water. The present study aimed to characterize the family of AOX genes in mandarin (Citrus clementina) and sweet orange (Citrus sinensis) at nucleotide and protein levels, including promoter analysis, phylogenetic analysis and C. sinensis gene expression. This study also aimed to do the homology modeling of one AOX isoform (CcAOXd). Moreover, the molecular docking of the CcAOXd protein with the ubiquinone (UQ) was performed. Four AOX genes were identified in each citrus species. These genes have an open reading frame (ORF) ranging from 852 bp to 1150 bp and a number of exons ranging from 4 to 9. The 1500 bp-upstream region of each AOX gene contained regulatory cis-elements related to internal and external response factors. CsAOX genes showed a differential expression in citrus tissues. All AOX proteins were predicted to be located in mitochondria. They contained the conserved motifs LET, NERMHL, LEEEA and RADE-H as well as several putative post-translational modification sites. The CcAOXd protein was modeled by homology to the AOX of Trypanosona brucei (45% of identity). The 3-D structure of CcAOXd showed the presence of two hydrophobic helices that could be involved in the anchoring of the protein in the inner mitochondrial membrane. The active site of the protein is located in a hydrophobic environment deep inside the AOX structure and contains a diiron center. The molecular docking of CcAOXd with UQ showed that the binding site is a recessed pocket formed by the helices and submerged in the membrane. These data are important for future functional studies of citrus AOX genes and/or proteins, as well as for biotechnological approaches leading to AOX inhibition using UQ homologs.
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Affiliation(s)
- Jacqueline Araújo Castro
- Universidade Estadual de Santa Cruz (UESC), Centro de Biotecnologia e Genética (CBG), Ilhéus, Bahia, Brazil
- Instituto Federal de Educação, Ciência e Tecnologia Baiano (IFBaiano), Santa Inês, Bahia, Brazil
| | | | - Raner José Santana Silva
- Universidade Estadual de Santa Cruz (UESC), Centro de Biotecnologia e Genética (CBG), Ilhéus, Bahia, Brazil
| | - Bruno Silva Andrade
- Universidade Estadual Sudoeste da Bahia (UESB), Av. José Moreira Sobrinho, Jequié, Bahia, Brazil
| | - Fabienne Micheli
- Universidade Estadual de Santa Cruz (UESC), Centro de Biotecnologia e Genética (CBG), Ilhéus, Bahia, Brazil
- CIRAD, UMR AGAP, F-34398 Montpellier, France
- * E-mail:
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12
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Tang Y, Sun X, Wen T, Liu M, Yang M, Chen X. Implications of terminal oxidase function in regulation of salicylic acid on soybean seedling photosynthetic performance under water stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 112:19-28. [PMID: 28024235 DOI: 10.1016/j.plaphy.2016.11.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 11/22/2016] [Accepted: 11/22/2016] [Indexed: 05/27/2023]
Abstract
The aim of this study is to investigate whether exogenous application of salicylic acid (SA) could modulate the photosynthetic capacity of soybean seedlings in water stress tolerance, and to clarify the potential functions of terminal oxidase (plastid terminal oxidase (PTOX) and alternative oxidase (AOX)) in SA' s regulation on photosynthesis. The effects of SA and water stress on gas exchange, pigment contents, chlorophyll fluorescence, enzymes (guaiacol peroxidase (POD; EC 1.11.1.7), superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APX; EC 1.11.1.11) and NADP-malate dehydrogenase (NADP-MDH; EC1.1.1.82)) activity and transcript levels of PTOX, AOX1, AOX2a, AOX2b were examined in a hydroponic cultivation system. Results indicate that water stress significantly decreased the photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (E), pigment contents (Chla + b, Chla/b, Car), maximum quantum yield of PSⅡphotochemistry (Fv/Fm), efficiency of excitation capture of open PSⅡcenter (Fv'/Fm'), quantum efficiency of PSⅡphotochemistry (ΦPSⅡ), photochemical quenching (qP), and increased malondialdehyde (MDA) content and the activity of all the enzymes. SA pretreatment led to significant decreases in Ci and MDA content, and increases in Pn, Gs, E, pigment contents, Fv/Fm, Fv'/Fm', ΦPSⅡ, qP, and the activity of all the enzymes. SA treatment and water stress alone significantly up-regulated the expression of PTOX, AOX1 and AOX2b. SA pretreatment further increased the transcript levels of PTOX and AOX2b of soybean seedling under water stress. These results indicate that SA application alleviates the water stress-induced decrease in photosynthesis may mainly through maintaining a lower reactive oxygen species (ROS) level, a greater PSⅡefficiency, and an enhanced alternative respiration and chlororespiration. PTOX and AOX may play important roles in SA-mediated resistance to water stress.
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Affiliation(s)
- Yanping Tang
- College of Agronomy, Sichuan Agricultural University, No.211, Huimin Road, Gongping Town, Wenjiang District, Chengdu, 611130, Sichuan, China; Agrotechnical Extension Station, Agricultural Bureau of Dazhou City, No.52, Heye Street, Tongchuan District, Dazhou, 635000, Sichuan, China.
| | - Xin Sun
- College of Agronomy, Sichuan Agricultural University, No.211, Huimin Road, Gongping Town, Wenjiang District, Chengdu, 611130, Sichuan, China.
| | - Tao Wen
- College of Agronomy, Sichuan Agricultural University, No.211, Huimin Road, Gongping Town, Wenjiang District, Chengdu, 611130, Sichuan, China.
| | - Mingjie Liu
- College of Agronomy, Sichuan Agricultural University, No.211, Huimin Road, Gongping Town, Wenjiang District, Chengdu, 611130, Sichuan, China
| | - Mingyan Yang
- College of Agronomy, Sichuan Agricultural University, No.211, Huimin Road, Gongping Town, Wenjiang District, Chengdu, 611130, Sichuan, China
| | - Xuefei Chen
- College of Agronomy, Sichuan Agricultural University, No.211, Huimin Road, Gongping Town, Wenjiang District, Chengdu, 611130, Sichuan, China
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Hu J, Chen G, Zhang H, Qian Q, Ding Y. Comparative transcript profiling of alloplasmic male-sterile lines revealed altered gene expression related to pollen development in rice (Oryza sativa L.). BMC PLANT BIOLOGY 2016; 16:175. [PMID: 27496332 PMCID: PMC4974769 DOI: 10.1186/s12870-016-0864-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/02/2016] [Indexed: 05/23/2023]
Abstract
BACKGROUND Cytoplasmic male sterility (CMS) is an ideal model for investigating the mitochondrial-nuclear interaction and down-regulated genes in CMS lines which might be the candidate genes for pollen development in rice. In this study, a set of rice alloplasmic sporophytic CMS lines was obtained by successive backcrossing of Meixiang B, with three different cytoplasmic types: D62A (D type), ZS97A (WA type) and XQZ-A (DA type). RESULTS Using microarray, the anther transcript profiles of the three indica rice CMS lines revealed 622 differentially expressed genes (DEGs) in each of the three CMS lines compared with the maintainer line Meixiang B. GO and MapMan analysis indicated that these DEGs were mainly involved in lipid metabolism and cell wall organization. Compared with the gene expression of sporophytic and gametophytic CMS lines, 303 DEGs were identified and 56 of them were down-regulated in all the CMS lines of rice. These down-regulated DEGs in the CMS lines were found to be involved in tapetum or cell wall formation and their suppressed expression might be related to male sterility. Weighted gene co-expression network analysis (WGCNA) revealed that two modules were significantly associated with male sterility and many hub genes that were differentially expressed in the CMS lines. CONCLUSION A large set of putative genes involved in anther development was identified in the present study. The results will give some information for the nuclear gene regulation by different cytoplasmic genotypes and provide a rich resource for further functional research on the pollen development in rice.
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Affiliation(s)
- Jihong Hu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Guanglong Chen
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Hongyuan Zhang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Qian Qian
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yi Ding
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
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14
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Jian W, Zhang DW, Zhu F, Wang SX, Pu XJ, Deng XG, Luo SS, Lin HH. Alternative oxidase pathway is involved in the exogenous SNP-elevated tolerance of Medicago truncatula to salt stress. JOURNAL OF PLANT PHYSIOLOGY 2016; 193:79-87. [PMID: 26962709 DOI: 10.1016/j.jplph.2016.01.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 12/06/2015] [Accepted: 01/22/2016] [Indexed: 05/04/2023]
Abstract
Exogenous application of sodium nitroprusside (SNP) would enhance the tolerance of plants to stress conditions. Some evidences suggested that nitric oxide (NO) could induce the expression of alternative oxidase (AOX). In this study, Medicago truncatula (Medicago) was chosen to study the role of AOX in the SNP-elevated resistance to salt stress. Our results showed that the expression of AOX genes (especially AOX1 and AOX2b1) and cyanide-resistant respiration rate (Valt) could be significantly induced by salt stress. Exogenous application of SNP could further enhance the expression of AOX genes and Valt. Exogenous application of SNP could alleviate the oxidative damage and photosynthetic damage caused by salt stress. However, the stress resistance was significantly decreased in the plants which were pretreated with n-propyl gallate (nPG). More importantly, the damage in nPG-pretreated plants could not be alleviated by application of SNP. Further study showed that effects of nPG on the activities of antioxidant enzymes were minor. These results showed that AOX pathway played an important role in the SNP-elevated resistance of Medicago to salt stress. AOX could contribute to regulating the accumulation of reactive oxygen (ROS) and protect of photosystem, and we proposed that all these were depend on the ability of maintaining the homeostasis of redox state.
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Affiliation(s)
- Wei Jian
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Da-wei Zhang
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Feng Zhu
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Shuo-xun Wang
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Xiao-jun Pu
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Xing-guang Deng
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Shi-shuai Luo
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Hong-hui Lin
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China.
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15
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Shukla P, Singh S, Dubey P, Singh A, Singh AK. Nitric oxide mediated amelioration of arsenic toxicity which alters the alternative oxidase (Aox1) gene expression in Hordeum vulgare L. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2015; 120:59-65. [PMID: 26036416 DOI: 10.1016/j.ecoenv.2015.05.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Revised: 05/16/2015] [Accepted: 05/18/2015] [Indexed: 06/04/2023]
Abstract
The role of nitric oxide (NO) as a key molecule in the signal transduction pathway of a biotic stress response has already been described. Recent studies indicate that it also participate in the signaling of abiotic stresses. In the present study, we showed the altered expression of stress responsive gene alternative oxidase (Aox1) in seedlings of barley (Hordeum vulgare L.) in response to arsenic toxicity. Arsenic toxicity decreased the germination percentage, biomass, chlorophyll and carotenoid content whereas, arsenic toxicity enhanced the MDA content and proline content in a dose dependent manner. Other enzyme activities like catalase and superoxide dismutase increased with the increase in concentrations but it fell down at higher concentration of arsenic. Pretreatment of nitric oxide results in the enhanced expression of alternative oxidase which showed the adaptation of alternative pathway during the arsenic stress and it also enhances the growth ability and adaptability towards the arsenic stress. The results support the conclusion that nitric oxide ameliorates the arsenic toxicity not only at the level of antioxidant defense but also by affecting other mechanism of detoxification.
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Affiliation(s)
- Pratiksha Shukla
- (a) Genotoxic Lab, Department of Botany, Udai Pratap Autonomous college, Varanasi 221002, India.
| | | | | | - Aradhana Singh
- (a) Genotoxic Lab, Department of Botany, Udai Pratap Autonomous college, Varanasi 221002, India
| | - A K Singh
- (a) Genotoxic Lab, Department of Botany, Udai Pratap Autonomous college, Varanasi 221002, India
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16
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Rogov AG, Sukhanova EI, Uralskaya LA, Aliverdieva DA, Zvyagilskaya RA. Alternative oxidase: distribution, induction, properties, structure, regulation, and functions. BIOCHEMISTRY (MOSCOW) 2015; 79:1615-34. [PMID: 25749168 DOI: 10.1134/s0006297914130112] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The respiratory chain in the majority of organisms with aerobic type metabolism features the concomitant existence of the phosphorylating cytochrome pathway and the cyanide- and antimycin A-insensitive oxidative route comprising a so-called alternative oxidase (AOX) as a terminal oxidase. In this review, the history of AOX discovery is described. Considerable evidence is presented that AOX occurs widely in organisms at various levels of organization and is not confined to the plant kingdom. This enzyme has not been found only in Archaea, mammals, some yeasts and protists. Bioinformatics research revealed the sequences characteristic of AOX in representatives of various taxonomic groups. Based on multiple alignments of these sequences, a phylogenetic tree was constructed to infer their possible evolution. The ways of AOX activation, as well as regulatory interactions between AOX and the main respiratory chain are described. Data are summarized concerning the properties of AOX and the AOX-encoding genes whose expression is either constitutive or induced by various factors. Information is presented on the structure of AOX, its active center, and the ubiquinone-binding site. The principal functions of AOX are analyzed, including the cases of cell survival, optimization of respiratory metabolism, protection against excess of reactive oxygen species, and adaptation to variable nutrition sources and to biotic and abiotic stress factors. It is emphasized that different AOX functions complement each other in many instances and are not mutually exclusive. Examples are given to demonstrate that AOX is an important tool to overcome the adverse aftereffects of restricted activity of the main respiratory chain in cells and whole animals. This is the first comprehensive review on alternative oxidases of various organisms ranging from yeasts and protists to vascular plants.
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Affiliation(s)
- A G Rogov
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
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17
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Costa JH, McDonald AE, Arnholdt-Schmitt B, Fernandes de Melo D. A classification scheme for alternative oxidases reveals the taxonomic distribution and evolutionary history of the enzyme in angiosperms. Mitochondrion 2014; 19 Pt B:172-83. [DOI: 10.1016/j.mito.2014.04.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 03/23/2014] [Accepted: 04/11/2014] [Indexed: 10/25/2022]
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18
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Budahn H, Barański R, Grzebelus D, Kiełkowska A, Straka P, Metge K, Linke B, Nothnagel T. Mapping genes governing flower architecture and pollen development in a double mutant population of carrot. FRONTIERS IN PLANT SCIENCE 2014; 5:504. [PMID: 25339960 PMCID: PMC4189388 DOI: 10.3389/fpls.2014.00504] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 09/09/2014] [Indexed: 05/20/2023]
Abstract
A linkage map of carrot (Daucus carota L.) was developed in order to study reproductive traits. The F2 mapping population derived from an initial cross between a yellow leaf (yel) chlorophyll mutant and a compressed lamina (cola) mutant with unique flower defects of the sporophytic parts of male and female organs. The genetic map has a total length of 781 cM and included 285 loci. The length of the nine linkage groups (LGs) ranged between 65 and 145 cM. All LGs have been anchored to the reference map. The objective of this study was the generation of a well-saturated linkage map of D. carota. Mapping of the cola-locus associated with flower development and fertility was successfully demonstrated. Two MADS-box genes (DcMADS3, DcMADS5) with prominent roles in flowering and reproduction as well as three additional genes (DcAOX2a, DcAOX2b, DcCHS2) with further importance for male reproduction were assigned to different loci that did not co-segregate with the cola-locus.
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Affiliation(s)
- Holger Budahn
- Institute for Breeding Research on Horticultural Crops, Federal Research Centre for Cultivated Plants, Julius Kühn-InstituteQuedlinburg, Germany
| | - Rafał Barański
- Department of Genetics, Plant Breeding and Seed Science, Faculty of Horticulture, University of AgricultureKraków, Poland
| | - Dariusz Grzebelus
- Department of Genetics, Plant Breeding and Seed Science, Faculty of Horticulture, University of AgricultureKraków, Poland
| | - Agnieszka Kiełkowska
- Department of Genetics, Plant Breeding and Seed Science, Faculty of Horticulture, University of AgricultureKraków, Poland
| | - Petra Straka
- Institute for Biosafety in Plant Biotechnology, Federal Research Centre for Cultivated Plants, Julius Kühn-InstituteQuedlinburg, Germany
| | - Kai Metge
- Institute for Biosafety in Plant Biotechnology, Federal Research Centre for Cultivated Plants, Julius Kühn-InstituteQuedlinburg, Germany
| | - Bettina Linke
- Department of Biology, Humboldt UniversityBerlin, Germany
| | - Thomas Nothnagel
- Institute for Breeding Research on Horticultural Crops, Federal Research Centre for Cultivated Plants, Julius Kühn-InstituteQuedlinburg, Germany
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20
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Ng S, De Clercq I, Van Aken O, Law SR, Ivanova A, Willems P, Giraud E, Van Breusegem F, Whelan J. Anterograde and retrograde regulation of nuclear genes encoding mitochondrial proteins during growth, development, and stress. MOLECULAR PLANT 2014; 7:1075-93. [PMID: 24711293 DOI: 10.1093/mp/ssu037] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mitochondrial biogenesis and function in plants require the expression of over 1000 nuclear genes encoding mitochondrial proteins (NGEMPs). The expression of these genes is regulated by tissue-specific, developmental, internal, and external stimuli that result in a dynamic organelle involved in both metabolic and a variety of signaling processes. Although the metabolic and biosynthetic machinery of mitochondria is relatively well understood, the factors that regulate these processes and the various signaling pathways involved are only beginning to be identified at a molecular level. The molecular components of anterograde (nuclear to mitochondrial) and retrograde (mitochondrial to nuclear) signaling pathways that regulate the expression of NGEMPs interact with chloroplast-, growth-, and stress-signaling pathways in the cell at a variety of levels, with common components involved in transmission and execution of these signals. This positions mitochondria as important hubs for signaling in the cell, not only in direct signaling of mitochondrial function per se, but also in sensing and/or integrating a variety of other internal and external signals. This integrates and optimizes growth with energy metabolism and stress responses, which is required in both photosynthetic and non-photosynthetic cells.
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Affiliation(s)
- Sophia Ng
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Australia Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, Hangzhou, 310058, P.R. China
| | - Inge De Clercq
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052 Gent, Belgium
| | - Olivier Van Aken
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Australia
| | - Simon R Law
- Department of Botany, ARC Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora 3086, Victoria, Australia
| | - Aneta Ivanova
- Department of Botany, ARC Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora 3086, Victoria, Australia
| | - Patrick Willems
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052 Gent, Belgium Department of Medical Protein Research and Department of Biochemistry, 9000 Ghent, Belgium
| | - Estelle Giraud
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Australia Present address: Illumina, ANZ, 1 International Court, Scoresby Victoria 3179, Australia
| | - Frank Van Breusegem
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052 Gent, Belgium
| | - James Whelan
- Department of Botany, ARC Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora 3086, Victoria, Australia
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21
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Cavalcanti JHF, Oliveira GM, Saraiva KDDC, Torquato JPP, Maia IG, de Melo DF, Costa JH. Identification of duplicated and stress-inducible Aox2b gene co-expressed with Aox1 in species of the Medicago genus reveals a regulation linked to gene rearrangement in leguminous genomes. JOURNAL OF PLANT PHYSIOLOGY 2013; 170:1609-19. [PMID: 23891563 DOI: 10.1016/j.jplph.2013.06.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 06/08/2013] [Accepted: 06/21/2013] [Indexed: 05/24/2023]
Abstract
In flowering plants, alternative oxidase (Aox) is encoded by 3-5 genes distributed in 2 subfamilies (Aox1 and Aox2). In several species only Aox1 is reported as a stress-responsive gene, but in the leguminous Vigna unguiculata Aox2b is also induced by stress. In this work we investigated the Aox genes from two leguminous species of the Medicago genus (Medicago sativa and Medicago truncatula) which present one Aox1, one Aox2a and an Aox2b duplication (named here Aox2b1 and Aox2b2). Expression analyses by semi-quantitative RT-PCR in M. sativa revealed that Aox1, Aox2b1 and Aox2b2 transcripts increased during seed germination. Similar analyses in leaves and roots under different treatments (SA, PEG, H2O2 and cysteine) revealed that these genes are also induced by stress, but with peculiar spatio-temporal differences. Aox1 and Aox2b1 showed basal levels of expression under control conditions and were induced by stress in leaves and roots. Aox2b2 presented a dual behavior, i.e., it was expressed only under stress conditions in leaves, and showed basal expression levels in roots that were induced by stress. Moreover, Aox2a was expressed at higher levels in leaves and during seed germination than in roots and appeared to be not responsive to stress. The Aox expression profiles obtained from a M. truncatula microarray dataset also revealed a stress-induced co-expression of Aox1, Aox2b1 and Aox2b2 in leaves and roots. These results reinforce the stress-inducible co-expression of Aox1/Aox2b in some leguminous plants. Comparative genomic analysis indicates that this regulation is linked to Aox1/Aox2b proximity in the genome as a result of the gene rearrangement that occurred in some leguminous plants during evolution. The differential expression of Aox2b1/2b2 suggests that a second gene has been originated by recent gene duplication with neofunctionalization.
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MESH Headings
- Chromosomes, Plant/genetics
- Gene Expression Profiling
- Gene Expression Regulation, Plant
- Gene Rearrangement/genetics
- Genes, Duplicate/genetics
- Genes, Plant/genetics
- Genome, Plant/genetics
- Germination/genetics
- Medicago/drug effects
- Medicago/enzymology
- Medicago/genetics
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- Molecular Sequence Data
- Oxidoreductases/genetics
- Oxidoreductases/metabolism
- Phylogeny
- Plant Growth Regulators/pharmacology
- Plant Leaves/enzymology
- Plant Leaves/genetics
- Plant Proteins/genetics
- Plant Proteins/metabolism
- Plant Roots/enzymology
- Plant Roots/genetics
- Promoter Regions, Genetic/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Stress, Physiological/drug effects
- Stress, Physiological/genetics
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Feng H, Guan D, Sun K, Wang Y, Zhang T, Wang R. Expression and signal regulation of the alternative oxidase genes under abiotic stresses. Acta Biochim Biophys Sin (Shanghai) 2013; 45:985-94. [PMID: 24004533 DOI: 10.1093/abbs/gmt094] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Plants in their natural environment frequently face various abiotic stresses, such as drought, high salinity, and chilling. Plant mitochondria contain an alternative oxidase (AOX), which is encoded by a small family of nuclear genes. AOX genes have been shown to be highly responsive to abiotic stresses. Using transgenic plants with varying levels of AOX expression, it has been confirmed that AOX genes are important for abiotic stress tolerance. Although the roles of AOX under abiotic stresses have been extensively studied and there are several excellent reviews on this topic, the differential expression patterns of the AOX gene family members and the signal regulation of AOX gene(s) under abiotic stresses have not been extensively summarized. Here, we review and discuss the current progress of these two important issues.
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Affiliation(s)
- Hanqing Feng
- College of Life Science, Northwest Normal University, Lanzhou 730070, China
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23
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Tarasenko VI, Garnik EY, Konstantinov YM. Rate of alternative electron transport in arabidopsis mitochondria affects the expression of the glutamate dehydrogenase gene gdh2. DOKL BIOCHEM BIOPHYS 2013; 452:234-6. [PMID: 24150580 DOI: 10.1134/s1607672913050037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Indexed: 11/23/2022]
Affiliation(s)
- V I Tarasenko
- Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk, 664033, Russia
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24
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Moore AL, Shiba T, Young L, Harada S, Kita K, Ito K. Unraveling the heater: new insights into the structure of the alternative oxidase. ANNUAL REVIEW OF PLANT BIOLOGY 2013; 64:637-63. [PMID: 23638828 DOI: 10.1146/annurev-arplant-042811-105432] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The alternative oxidase is a membrane-bound ubiquinol oxidase found in the majority of plants as well as many fungi and protists, including pathogenic organisms such as Trypanosoma brucei. It catalyzes a cyanide- and antimycin-A-resistant oxidation of ubiquinol and the reduction of oxygen to water, short-circuiting the mitochondrial electron-transport chain prior to proton translocation by complexes III and IV, thereby dramatically reducing ATP formation. In plants, it plays a key role in cellular metabolism, thermogenesis, and energy homeostasis and is generally considered to be a major stress-induced protein. We describe recent advances in our understanding of this protein's structure following the recent successful crystallization of the alternative oxidase from T. brucei. We focus on the nature of the active site and ubiquinol-binding channels and propose a mechanism for the reduction of oxygen to water based on these structural insights. We also consider the regulation of activity at the posttranslational and retrograde levels and highlight challenges for future research.
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Affiliation(s)
- Anthony L Moore
- Biochemistry and Molecular Biology, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom.
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25
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Nargang FE, Adames K, Rüb C, Cheung S, Easton N, Nargang CE, Chae MS. Identification of genes required for alternative oxidase production in the Neurospora crassa gene knockout library. G3 (BETHESDA, MD.) 2012; 2:1345-56. [PMID: 23173086 PMCID: PMC3484665 DOI: 10.1534/g3.112.004218] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Accepted: 09/04/2012] [Indexed: 01/22/2023]
Abstract
The alternative oxidase (AOX) of Neurospora crassa transfers electrons from ubiquinol to oxygen. The enzyme is not expressed under normal conditions. However, when the function of the standard electron transport chain is compromised, AOX is induced, providing cells with a means to continue respiration and growth. Induction of the enzyme represents a form of retrograde regulation because AOX is encoded by a nuclear gene that responds to signals produced from inefficiently functioning mitochondria. To identify genes required for AOX expression, we have screened the N. crassa gene knockout library for strains that are unable to grow in the presence of antimycin A, an inhibitor of complex III of the standard electron transport chain. From the 7800 strains containing knockouts of different genes, we identified 62 strains that have reduced levels of AOX when grown under conditions known to induce the enzyme. Some strains have virtually no AOX, whereas others have only a slight reduction of the protein. A broad range of seemingly unrelated functions are represented in the knockouts. For example, we identified transcription factors, kinases, the mitochondrial import receptor Tom70, three subunits of the COP9 signalosome, a monothiol glutaredoxin, and several hypothetical proteins as being required for wild-type levels of AOX production. Our results suggest that defects in many signaling or metabolic pathways have a negative effect on AOX expression and imply that complex systems control production of the enzyme.
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Affiliation(s)
- Frank E Nargang
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
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Comparison of intact Arabidopsis thaliana leaf transcript profiles during treatment with inhibitors of mitochondrial electron transport and TCA cycle. PLoS One 2012; 7:e44339. [PMID: 23028523 PMCID: PMC3445595 DOI: 10.1371/journal.pone.0044339] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 08/02/2012] [Indexed: 01/02/2023] Open
Abstract
Plant mitochondria signal to the nucleus leading to altered transcription of nuclear genes by a process called mitochondrial retrograde regulation (MRR). MRR is implicated in metabolic homeostasis and responses to stress conditions. Mitochondrial reactive oxygen species (mtROS) are a MRR signaling component, but whether all MRR requires ROS is not established. Inhibition of the cytochrome respiratory pathway by antimycin A (AA) or the TCA cycle by monofluoroacetate (MFA), each of which initiates MRR, can increase ROS production in some plant cells. We found that for AA and MFA applied to leaves of soil-grown Arabidopsis thaliana plants, ROS production increased with AA, but not with MFA, allowing comparison of transcript profiles under different ROS conditions during MRR. Variation in transcript accumulation over time for eight nuclear encoded mitochondrial protein genes suggested operation of both common and distinct signaling pathways between the two treatments. Consequences of mitochondrial perturbations for the whole transcriptome were examined by microarray analyses. Expression of 1316 and 606 genes was altered by AA and MFA, respectively. A subset of genes was similarly affected by both treatments, including genes encoding photosynthesis-related proteins. MFA treatment resulted in more down-regulation. Functional gene category (MapMan) and cluster analyses showed that genes with expression levels affected by perturbation from AA or MFA inhibition were most similarly affected by biotic stresses such as pathogens. Overall, the data provide further evidence for the presence of mtROS-independent MRR signaling, and support the proposed involvement of MRR and mitochondrial function in plant responses to biotic stress.
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Yang X, Liu X, Lv W, Li L, Shi Q, Yang J, Zhang M. Reduced expression of BjRCE1 gene modulated by nuclear-cytoplasmic incompatibility alters auxin response in cytoplasmic male-sterile Brassica juncea. PLoS One 2012; 7:e38821. [PMID: 22719957 PMCID: PMC3377708 DOI: 10.1371/journal.pone.0038821] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 05/11/2012] [Indexed: 11/30/2022] Open
Abstract
The signal from organelle to nucleus, namely retrograde regulation of nuclear gene expression, was largely unknown. Due to the nuclear-cytoplasmic incompatibility in cytoplasmic male-sterile (CMS) plants, we employed CMS Brassica juncea to investigate the retrograde regulation of nuclear gene expression in this study. We studied how reduced BjRCE1 gene expression caused by the nuclear-cytoplasmic incompatibility altered the auxin response in CMS of B. juncea. We isolated the BjRCE1 gene that was located in the nucleus from B. juncea. Over-expression of BjRCE1 enhanced auxin response in transgenic Arabidopsis. The expression of BjRCE1 was significantly reduced in CMS compared with its maintainer fertile (MF) line of B. juncea. There were fewer lateral roots in CMS than MF under normal and treatment of indole-3-acetic acid (IAA) conditions. Expression patterns of several auxin-related genes together with their phenotypes indicated a reduced auxin response in CMS compared to MF. The phenotypes of auxin response and auxin-related gene expression pattern could be mimicked by inhibiting mitochondrial function in MF. Taken together, we proposed reduced expression of BjRCE1 gene modulated by nuclear-cytoplasmic incompatibility alters auxin response in CMS B. juncea. This may be an important mechanism of retrograde regulation of nuclear gene expression in plants.
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Affiliation(s)
- Xiaodong Yang
- Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, People’s Republic of China
- Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, People’s Republic of China
| | - Xunyan Liu
- College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, People’s Republic of China
| | - Wenhui Lv
- Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, People’s Republic of China
- Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, People’s Republic of China
| | - Lu Li
- Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, People’s Republic of China
- Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, People’s Republic of China
| | - Qianqian Shi
- Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, People’s Republic of China
- Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, People’s Republic of China
| | - Jinghua Yang
- Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, People’s Republic of China
- Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, People’s Republic of China
| | - Mingfang Zhang
- Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, People’s Republic of China
- Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, People’s Republic of China
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cDNA cloning and expression analysis of a putative alternative oxidase HsAOX1 from wild barley (Hordeum spontaneum). Genes Genomics 2012. [DOI: 10.1007/s13258-011-0164-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Schwarzländer M, König AC, Sweetlove LJ, Finkemeier I. The impact of impaired mitochondrial function on retrograde signalling: a meta-analysis of transcriptomic responses. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1735-50. [PMID: 22131156 DOI: 10.1093/jxb/err374] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Mitochondria occupy a central position in cellular metabolism. Their protein complement must therefore be dynamically adjusted to the metabolic demands of the cell. As >95% of mitochondrial proteins are encoded by nuclear DNA, regulation of the mitochondrial proteome requires signals that sense the status of the organelle and communicate it back to the nucleus. This is referred to as retrograde signalling. Mitochondria are tightly integrated into the network of cellular processes, and the output of mitochondrial retrograde signalling therefore not only feeds back to the mitochondrion, but also regulates functions across the cell. A number of transcriptomic studies have assessed the role of retrograde signalling in plants. However, single studies of a specific mitochondrial dysfunction may also measure secondary effects in addition to the specific transcriptomic output of mitochondrial signals. To gain an improved understanding of the output and role of mitochondrial retrograde signalling, a meta-analysis of 11 transcriptomic data sets from different models of plant mitochondrial dysfunction was performed. Comparing microarray data from stable mutants and short-term chemical treatments revealed unique features and commonalities in the responses that are under mitochondrial retrograde control. In particular, a common regulation of transcripts of the following functional categories was observed: plant-pathogen interactions, protein biosynthesis, and light reactions of photosynthesis. The possibility of a novel mode of interorganellar signalling, in which the mitochondrion influences processes in the plastid and other parts of the cell, is discussed.
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Affiliation(s)
- Markus Schwarzländer
- Department of Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2, D-82152 Planegg-Martinsried, Germany
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30
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Matsuo M, Hachisu R, Tabata S, Fukuzawa H, Obokata J. Transcriptome analysis of respiration-responsive genes in Chlamydomonas reinhardtii: mitochondrial retrograde signaling coordinates the genes for cell proliferation with energy-producing metabolism. PLANT & CELL PHYSIOLOGY 2011; 52:333-43. [PMID: 21149298 DOI: 10.1093/pcp/pcq192] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plant organelles are not only the recipients of signals from the nucleus, but also elicit signals to regulate nuclear genes; the latter process is called retrograde regulation. We previously reported a novel mitochondrial retrograde regulation in Chlamydomonas reinhardtii; nuclear photosynthesis genes are regulated in response to mitochondrial respiratory electron transport (RET). However, the physiological roles of this retrograde regulation are not yet fully understood. In this study, we performed a genome-wide transcriptome analysis of this alga to reveal what kinds of genes are responsive to this RET signal, using Chlamydomonas macroarrays containing 10,368 expressed sequence tag clones. From the analysis, we identified 147 inducible and 35 repressive genes based on a couple of criteria: induction/repression by activated respiration caused by exogenously added acetate, and the cancellations of these responses by treatment with antimycin A, an inhibitor of RET. Interestingly, genes for respiration, photosynthesis, glycolysis/gluconeogenesis, protein biosynthesis, cell wall biogenesis and flagella were significantly induced by RET-derived signals. From these findings, we discuss the physiological role of mitochondrial retrograde signaling in this unicellular alga, in terms of the coordination of cell proliferation with energy-producing metabolism.
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Affiliation(s)
- Mitsuhiro Matsuo
- Kyoto Prefectural University, 1-5 Hangi-cho, Shimogamo, Sakyo-ku, Kyoto, 606-8522 Japan
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31
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Costa JH, Mota EF, Cambursano MV, Lauxmann MA, de Oliveira LMN, Silva Lima MDG, Orellano EG, Fernandes de Melo D. Stress-induced co-expression of two alternative oxidase (VuAox1 and 2b) genes in Vigna unguiculata. JOURNAL OF PLANT PHYSIOLOGY 2010; 167:561-70. [PMID: 20005596 DOI: 10.1016/j.jplph.2009.11.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 11/01/2009] [Accepted: 11/02/2009] [Indexed: 05/21/2023]
Abstract
Cowpea (Vigna unguiculata) alternative oxidase is encoded by a small multigene family (Aox1, 2a and 2b) that is orthologous to the soybean Aox family. Like most of the identified Aox genes in plants, VuAox1 and VuAox2 consist of 4 exons interrupted by 3 introns. Alignment of the orthologous Aox genes revealed high identity of exons and intron variability, which is more prevalent in Aox1. In order to determine Aox gene expression in V. unguiculata, a steady-state analysis of transcripts involved in seed development (flowers, pods and dry seeds) and germination (soaked seeds) was performed and systemic co-expression of VuAox1 and VuAox2b was observed during germination. The analysis of Aox transcripts in leaves from seedlings under different stress conditions (cold, PEG, salicylate and H2O2 revealed stress-induced co-expression of both VuAox genes. Transcripts of VuAox2a and 2b were detected in all control seedlings, which was not the case for VuAox1 mRNA. Estimation of the primary transcript lengths of V. unguiculata and soybean Aox genes showed an intron length reduction for VuAox1 and 2b, suggesting that the two genes have converged in transcribed sequence length. Indeed, a bioinformatics analysis of VuAox1 and 2b promoters revealed a conserved region related to a cis-element that is responsive to oxidative stress. Taken together, the data provide evidence for co-expression of Aox1 and Aox2b in response to stress and also during the early phase of seed germination. The dual nature of VuAox2b expression (constitutive and induced) suggests that the constitutive Aox2b gene of V. unguiculata has acquired inducible regulatory elements.
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Affiliation(s)
- José Hélio Costa
- Department of Biochemistry and Molecular Biology, Federal University of Ceara, 60455-760 Fortaleza, Ceará, Brazil
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32
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Fujii S, Yamada M, Fujita M, Itabashi E, Hamada K, Yano K, Kurata N, Toriyama K. Cytoplasmic-nuclear genomic barriers in rice pollen development revealed by comparison of global gene expression profiles among five independent cytoplasmic male sterile lines. PLANT & CELL PHYSIOLOGY 2010; 51:610-20. [PMID: 20203238 DOI: 10.1093/pcp/pcq026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Cytoplasmic male sterility (CMS) is one of the most ideal phenomena known in higher plants to describe the incompatibilities between mitochondrial-nuclear genomic interactions. To elucidate the dependency of pollen development on mitochondrial genotypes and cytoplasmic-nuclear genomic barriers, we employed five CMS isogenic lines of rice, CW-, W11-, LD-, BT- and WA-type CMS lines, that exhibit distinct pollen-defective phenotypes, and we characterized the CMS phenotypes and the nuclear gene expression patterns in conjunction with their mitochondrial genomic structures. These five CMS lines carried independent mitotypes, and W11, LD and BT mitochondrial genomes were relatively close with respect to their phylogeny. In anthers at the uninucleate microspore and bicellular pollen stages, 8,199 genes significantly changed their expression in at least one of the CMS lines. Common expression patterns were observed in BT, LD and W11 after k-means clustering. Among the genes encoding putative mitochondrial proteins, ALTERNATIVE OXIDASE 1A, a gene for the well-known mitochondrial stress marker, was included in the group ectopically up-regulated in anthers at the bicellular pollen stage of BT, LD and W11. Several other clusters were also regulated in a cytoplasm-specific manner during pollen development. These clear similarities in gene regulatory networks of BT-, LD- and W11-CMS lines indicate that the phylogenetic relationships of the mitochondrial genotypes are strongly correlated with nuclear gene expression patterns and pollen abortion phenotypes, providing evidence of the mitochondrial epistacy over the nuclear genome during pollen development.
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Affiliation(s)
- Sota Fujii
- Laboratory of Environmental Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555 Japan
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33
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Chai TT, Simmonds D, Day DA, Colmer TD, Finnegan PM. Photosynthetic performance and fertility are repressed in GmAOX2b antisense soybean. PLANT PHYSIOLOGY 2010; 152:1638-49. [PMID: 20097793 PMCID: PMC2832272 DOI: 10.1104/pp.109.149294] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 01/19/2010] [Indexed: 05/07/2023]
Abstract
The alternative oxidase (AOX) is a cyanide-resistant oxidase that provides an alternative outlet for electrons from the respiratory electron transport chain embedded in the inner membrane of plant mitochondria. Examination of soybean (Glycine max) plants carrying a GmAOX2b antisense gene showed AOX to have a central role in reproductive development and fecundity. In three independently transformed antisense lines, seed set was reduced by 16% to 43%, whereas ovule abortion increased by 1.2- to 1.7-fold when compared with nontransgenic transformation control plants. Reduced fecundity was associated with reductions in whole leaf cyanide-resistant, salicylhydroxamic acid-sensitive respiration and net photosynthesis, but there was no change in total respiration in the dark. The frequency of potential fertilization events was reduced by at least one-third in the antisense plants as a likely consequence of prefertilization defects. Pistils of the antisense plants contained a higher proportion of immature-sized, nonfertile embryo sacs compared with nontransgenic control plants. Increased rates of pollen abortion in vivo and reduced rates of pollen germination in vitro suggested that the antisense gene compromised pollen development and function. Reciprocal crosses between antisense and nontransgenic plants revealed that pollen produced by antisense plants was less active in fertilization. Taken together, the results presented here indicate that AOX expression has an important role in determining normal gametophyte development and function.
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Affiliation(s)
| | | | | | | | - Patrick M. Finnegan
- School of Plant Biology and Institute of Agriculture, Faculty of Natural and Agricultural Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia (T.-T.C., T.D.C., P.M.F.); Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada K1A 0C6 (D.S.); and Australian Research Council Centre of Excellence in Plant Energy Biology, School of Biological Sciences, Flinders University, Adelaide, South Australia 5001, Australia (D.A.D.)
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34
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Polidoros AN, Mylona PV, Arnholdt-Schmitt B. Aox gene structure, transcript variation and expression in plants. PHYSIOLOGIA PLANTARUM 2009; 137:342-53. [PMID: 19781002 DOI: 10.1111/j.1399-3054.2009.01284.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Alternative oxidase (Aox) has been proposed as a functional marker for breeding stress tolerant plant varieties. This requires presence of polymorphic Aox allele sequences in plants that affect plant phenotype in a recognizable way. In this review, we examine the hypothesis that organization of genomic Aox sequences and gene expression patterns are highly variable in relation to the possibility that such a variation may allow development of Aox functional markers in plants. Aox is encoded by a small multigene family, typically with four to five members in higher plants. The predominant structure of genomic Aox sequences is that of four exons interrupted by three introns at well conserved positions. Evolutionary intron loss and gain has resulted in the variation of intron numbers in some Aox members that may harbor two to four introns and three to five exons in their sequence. Accumulating evidence suggests that Aox gene structure is polymorphic enough to allow development of Aox markers in many plant species. However, the functional significance of Aox structural variation has not been examined exhaustively. Aox expression patterns display variability and typically Aox genes fall into two discrete subfamilies, Aox1 and Aox2, the former being present in all plants and the latter restricted in eudicot species. Typically, although not exclusively, the Aox1-type genes are induced by many different kinds of stress, whereas Aox2-type genes are expressed in a constitutive or developmentally regulated way. Specific Aox alleles are among the first and most intensively stress-induced genes in several experimental systems involving oxidative stress. Differential response of Aox genes to stress may provide a flexible plan of plant defense where an energy-dissipating system in mitochondria is involved. Evidence to link structural variation and differential allele expression patterns is scarce. Much research is still required to understand the significance of polymorphisms within AOX gene sequences for gene regulation and its potential for breeding on important agronomic traits. Association studies and mapping approaches will be helpful to advance future perspectives for application more efficiently.
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Affiliation(s)
- Alexios N Polidoros
- Department of Genetics and Plant Breeding, School of Agriculture, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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35
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Rasmusson AG, Fernie AR, van Dongen JT. Alternative oxidase: a defence against metabolic fluctuations? PHYSIOLOGIA PLANTARUM 2009; 137:371-82. [PMID: 19558416 DOI: 10.1111/j.1399-3054.2009.01252.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
An increasing number of oscillating or fluctuating cellular systems have been recently described following the adaptation of fluorescent technology. In diverse organisms, these variously involve signalling factors, heat production, central metabolism and reactive oxygen species (ROS). In response to many plant stresses and primarily via the influence of ROS, changes in mRNA and protein levels or in vivo activity of alternative oxidase are often observed. However, in several investigations, a lack of correlation between the mRNA, protein and in vivo activity has been evident. This discrepancy has made it questionable whether the induction of alternative oxidase has importance in regulating alternative pathway activity in vivo, or being diagnostic for a role of alternative oxidase in stress tolerance and ROS avoidance. Here, we suggest a role of alternative oxidase in counteracting deleterious short-term metabolic fluctuations, especially under stress conditions. This model emphasizes the importance of peak activity for establishing protein levels and allows an amalgamation of the present status of physiological, cellular and molecular knowledge.
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Affiliation(s)
- Allan G Rasmusson
- Department of Cell and Organism Biology, Lund University, Sölvegatan 35B, SE-22362 Lund, Sweden.
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36
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Matos AR, Mendes AT, Scotti-Campos P, Arrabaça JD. Study of the effects of salicylic acid on soybean mitochondrial lipids and respiratory properties using the alternative oxidase as a stress-reporter protein. PHYSIOLOGIA PLANTARUM 2009; 137:485-97. [PMID: 19508334 DOI: 10.1111/j.1399-3054.2009.01250.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Biotic and abiotic stresses can lead to modifications in the lipid composition of cell membranes. Although mitochondria appear to be implicated in stress responses, little is known about the membrane lipid changes that occur in these organelles in plants. Besides cytochrome c oxidase, plant mitochondria have an alternative oxidase (AOX) that accepts electrons directly from ubiquinol, dissipating energy as heat. AOX upregulation occurs under a variety of stresses and its induction by salicylic acid (SA) has been observed in different plant species. AOX was also suggested to be used as a functional marker for cell reprogramming under stress. In the present study, we have used etiolated soybean (Glycine max (L.) Merr. cv Cresir) seedlings to study the effects of SA treatment on the lipid composition and the respiratory properties of hypocotyl mitochondria. AOX expression was studied in detail, as a reporter protein, to evaluate whether modifications in mitochondrial energy metabolism were occurring. In mitochondria extracted from SA-treated seedlings, AOX capacity and protein contents increased. Both AOX1 and AOX2b transcripts accumulated in response to SA, but with different kinetics. A reduction in external NADH oxidation capacity was observed, whereas succinate respiration remained unchanged. The phospholipid composition of mitochondria remained similar in control and SA-treated plants, but a reduction in the relative amount of linolenic acid was observed in phosphatidylcholine, phosphatidylethanolamine and cardiolipin. The possible causes of the fatty acid modifications observed, and the implications for mitochondrial metabolism are discussed.
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Affiliation(s)
- Ana Rita Matos
- Centro de Engenharia Biológica, Departamento de Biologia Vegetal, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
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Yoshida K, Noguchi K. Differential Gene Expression Profiles of the Mitochondrial Respiratory Components in Illuminated Arabidopsis Leaves. ACTA ACUST UNITED AC 2009; 50:1449-62. [DOI: 10.1093/pcp/pcp090] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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38
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Fujii S, Yamada M, Toriyama K. Cytoplasmic male sterility-related protein kinase, OsNek3, is regulated downstream of mitochondrial protein phosphatase 2C, DCW11. PLANT & CELL PHYSIOLOGY 2009; 50:828-37. [PMID: 19224952 DOI: 10.1093/pcp/pcp026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
OsNek3 (Oryza sativa L. NIMA-related kinase) and DCW11 encoding a mitochondrial putative protein phosphatase 2C were found in our previous microarray study as down-regulated genes in the rice CW-CMS line, which lacked pollen germination ability. Further analysis of DCW11 revealed that DCW11 is strongly correlated with CW-CMS occurrence. Here we show the relationship between OsNek3 and DCW11. OsNek3 was preferentially expressed in mature pollen. A knockout mutant with Tos17 inserted into OsNek3 did not show any pollen-defective phenotype. On the other hand, plants overexpressing OsNek3 occasionally produced a peculiar pollen structure in which the outer cell wall of four pollen grains fused together even at the mature pollen stages, which resembled that of quartet mutants in Arabidopsis. OsNek3 was shown to interact with a LIM domain-containing protein, OsPLIM2b, whose expression was strongly specific in mature pollen, suggesting that OsNek3 might play a role in pollen germination. OsNek3 was shown to be down-regulated in DCW11-knockdown lines, whereas osnek3 mutation did not result in DCW11 down-regulation. These results suggest that OsNek3 is downstream of DCW11 in retrograde signaling from the mitochondria to the nucleus and is involved in CW-CMS.
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Affiliation(s)
- Sota Fujii
- Laboratory of Environmental Biotechnology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
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Tarasenko VI, Garnik EY, Shmakov VN, Konstantinov YM. Induction of Arabidopsis gdh2 gene expression during changes in redox state of the mitochondrial respiratory chain. BIOCHEMISTRY (MOSCOW) 2009; 74:47-53. [DOI: 10.1134/s0006297909010076] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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Garmier M, Carroll AJ, Delannoy E, Vallet C, Day DA, Small ID, Millar AH. Complex I dysfunction redirects cellular and mitochondrial metabolism in Arabidopsis. PLANT PHYSIOLOGY 2008; 148:1324-41. [PMID: 18784283 PMCID: PMC2577250 DOI: 10.1104/pp.108.125880] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2008] [Accepted: 09/05/2008] [Indexed: 05/19/2023]
Abstract
Mitochondrial complex I is a major avenue for reduced NAD oxidation linked to oxidative phosphorylation in plants. However, the plant enzyme has structural and functional features that set it apart from its counterparts in other organisms, raising questions about the physiological significance of this complex in plants. We have developed an experimental model in which rotenone, a classic complex I inhibitor, has been applied to Arabidopsis (Arabidopsis thaliana) cell suspension cultures in order to dissect early metabolic adjustments involved in cell acclimation to mitochondrial dysfunction. Rotenone induced a transitory decrease in cellular respiration (0-4 h after treatment). Cell respiration then progressively recovered and reached a steady state at 10 to 12 h after treatment. Complex I inhibition by rotenone did not induce obvious oxidative stress or cell death but affected longer term cell growth. Integrated analyses of gene expression, the mitochondrial proteome, and changes in primary metabolism indicated that rotenone treatment caused changes in mitochondrial function via alterations in specific components. A physical disengagement of glycolytic activities associated with the mitochondrial outer membrane was observed, and the tricarboxylic acid cycle was altered. Amino acid and organic acid pools were also modified by rotenone treatment, with a marked early decrease of 2-oxoglutarate, aspartate, and glutamine pools. These data demonstrate that, in Arabidopsis cells, complex I inhibition by rotenone induces significant remodeling of metabolic pathways involving the mitochondria and other compartments and point to early metabolic changes in response to mitochondrial dysfunction.
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Affiliation(s)
- Marie Garmier
- Australian Research Council Centre of Excellence in Plant Energy Biology M316, University of Western Australia, Crawley, Western Australia 6009, Australia
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41
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McDonald AE. Alternative oxidase: an inter-kingdom perspective on the function and regulation of this broadly distributed 'cyanide-resistant' terminal oxidase. FUNCTIONAL PLANT BIOLOGY : FPB 2008; 35:535-552. [PMID: 32688810 DOI: 10.1071/fp08025] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2008] [Accepted: 07/11/2008] [Indexed: 06/11/2023]
Abstract
Alternative oxidase (AOX) is a terminal quinol oxidase located in the respiratory electron transport chain that catalyses the oxidation of quinol and the reduction of oxygen to water. However, unlike the cytochrome c oxidase respiratory pathway, the AOX pathway moves fewer protons across the inner mitochondrial membrane to generate a proton motive force that can be used to synthesise ATP. The energy passed to AOX is dissipated as heat. This appears to be very wasteful from an energetic perspective and it is likely that AOX fulfils some physiological function(s) that makes up for its apparent energetic shortcomings. An examination of the known taxonomic distribution of AOX and the specific organisms in which AOX has been studied has been used to explore themes pertaining to AOX function and regulation. A comparative approach was used to examine AOX function as it relates to the biochemical function of the enzyme as a quinol oxidase and associated topics, such as enzyme structure, catalysis and transcriptional expression and post-translational regulation. Hypotheses that have been put forward about the physiological function(s) of AOX were explored in light of some recent discoveries made with regard to species that contain AOX. Fruitful areas of research for the AOX community in the future have been highlighted.
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Affiliation(s)
- Allison E McDonald
- Department of Biology, The University of Western Ontario, Biological and Geological Sciences Building, London, Ontario N6A 5B7, Canada. Email
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Ho LHM, Giraud E, Uggalla V, Lister R, Clifton R, Glen A, Thirkettle-Watts D, Van Aken O, Whelan J. Identification of regulatory pathways controlling gene expression of stress-responsive mitochondrial proteins in Arabidopsis. PLANT PHYSIOLOGY 2008; 147:1858-73. [PMID: 18567827 PMCID: PMC2492625 DOI: 10.1104/pp.108.121384] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Accepted: 06/11/2008] [Indexed: 05/17/2023]
Abstract
In this study we analyzed transcript abundance and promoters of genes encoding mitochondrial proteins to identify signaling pathways that regulate stress-induced gene expression. We used Arabidopsis (Arabidopsis thaliana) alternative oxidase AOX1a, external NADP H-dehydrogenase NDB2, and two additional highly stress-responsive genes, At2g21640 and BCS1. As a starting point, the promoter region of AOX1a was analyzed and functional analysis identified 10 cis-acting regulatory elements (CAREs), which played a role in response to treatment with H(2)O(2), rotenone, or both. Six of these elements were also functional in the NDB2 promoter. The promoter region of At2g21640, previously defined as a hallmark of oxidative stress, shared two functional CAREs with AOX1a and was responsive to treatment with H(2)O(2) but not rotenone. Microarray analysis further supported that signaling pathways induced by H(2)O(2) and rotenone are not identical. The promoter of BCS1 was not responsive to H(2)O(2) or rotenone, but highly responsive to salicylic acid (SA), whereas the promoters of AOX1a and NDB2 were unresponsive to SA. Analysis of transcript abundance of these genes in a variety of defense signaling mutants confirmed that BCS1 expression is regulated in a different manner compared to AOX1a, NDB2, and At2g21640. These mutants also revealed a pathway associated with programmed cell death that regulated AOX1a in a manner distinct from the other genes. Thus, at least three distinctive pathways regulate mitochondrial stress response at a transcriptional level, an SA-dependent pathway represented by BCS1, a second pathway that represents a convergence point for signals generated by H(2)O(2) and rotenone on multiple CAREs, some of which are shared between responsive genes, and a third pathway that acts via EDS1 and PAD4 regulating only AOX1a. Furthermore, posttranscriptional regulation accounts for changes in transcript abundance by SA treatment for some genes.
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Affiliation(s)
- Lois H M Ho
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley 6009, Western Australia, Australia
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Millar AH, Small ID, Day DA, Whelan J. Mitochondrial biogenesis and function in Arabidopsis. THE ARABIDOPSIS BOOK 2008; 6:e0111. [PMID: 22303236 DOI: 10.1199/tab.0105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mitochondria represent the powerhouse of cells through their synthesis of ATP. However, understanding the role of mitochondria in the growth and development of plants will rely on a much deeper appreciation of the complexity of this organelle. Arabidopsis research has provided clear identification of mitochondrial components, allowed wide-scale analysis of gene expression, and has aided reverse genetic manipulation to test the impact of mitochondrial component loss on plant function. Forward genetics in Arabidopsis has identified mitochondrial involvement in mutations with notable impacts on plant metabolism, growth and development. Here we consider the evidence for components involved in mitochondria biogenesis, metabolism and signalling to the nucleus.
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Millar AH, Small ID, Day DA, Whelan J. Mitochondrial biogenesis and function in Arabidopsis. THE ARABIDOPSIS BOOK 2008; 6:e0111. [PMID: 22303236 PMCID: PMC3243404 DOI: 10.1199/tab.0111] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Mitochondria represent the powerhouse of cells through their synthesis of ATP. However, understanding the role of mitochondria in the growth and development of plants will rely on a much deeper appreciation of the complexity of this organelle. Arabidopsis research has provided clear identification of mitochondrial components, allowed wide-scale analysis of gene expression, and has aided reverse genetic manipulation to test the impact of mitochondrial component loss on plant function. Forward genetics in Arabidopsis has identified mitochondrial involvement in mutations with notable impacts on plant metabolism, growth and development. Here we consider the evidence for components involved in mitochondria biogenesis, metabolism and signalling to the nucleus.
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Affiliation(s)
- A. Harvey Millar
- Australian Research Council (ARC) Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009
| | - Ian D. Small
- Australian Research Council (ARC) Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009
| | - David A. Day
- School of Biological Sciences, The University of Sydney 2006, NSW, Australia
| | - James Whelan
- Australian Research Council (ARC) Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009
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Mitochondrial retrograde regulation tuning fork in nuclear genes expressions of higher plants. J Genet Genomics 2008; 35:65-71. [DOI: 10.1016/s1673-8527(08)60010-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 11/08/2007] [Accepted: 11/09/2007] [Indexed: 11/20/2022]
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Aranha MM, Matos AR, Teresa Mendes A, Vaz Pinto V, Rodrigues CMP, Arrabaça JD. Dinitro-o-cresol induces apoptosis-like cell death but not alternative oxidase expression in soybean cells. JOURNAL OF PLANT PHYSIOLOGY 2007; 164:675-84. [PMID: 17223224 DOI: 10.1016/j.jplph.2006.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Revised: 09/14/2006] [Accepted: 09/15/2006] [Indexed: 05/13/2023]
Abstract
In plants, programmed cell death is thought to be activated during differentiation and in response to biotic and abiotic stresses. Although its mechanisms are far less clear, several morphological and biochemical features have been described in different experimental systems, including DNA laddering and cytosolic protease activation. Moreover, plant mitochondria have an alternative terminal oxidase (AOX), which is thought to be involved in protection against increased reactive oxygen species production, perhaps representing a mechanism to prevent programmed cell death. In this study, we analysed cell death induced by the herbicide dinitro-o-cresol (DNOC) in soybean (Glycine max) suspension cell cultures and evaluated biochemical and molecular events associated with programmed cell death. AOX capacity and expression were also determined. DNOC-treated cells showed fragmented nuclear DNA as assessed by an in situ assay that detects 3'-OH ends. In addition, specific colorimetric assays and immunoblot analysis revealed activation of caspase-3-like proteins and release of cytochrome c from mitochondria, respectively, confirming the apoptotic-like phenotype. Surprisingly, AOX capacity and protein levels decreased in DNOC-treated cells, suggesting no association between cell death and AOX under these experimental conditions. In conclusion, the results show that DNOC induces programmed cell death in soybean cells, suggesting that plants and animals might share similar pathways. Further, the role of AOX in cell death has not been confirmed, and may depend on the nature and intensity of stress conditions.
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Affiliation(s)
- Márcia M Aranha
- Centro de Engenharia Biológica and Departamento de Biologia Vegetal, Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016 Lisbon, Lisbon, Portugal
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Costa JH, Jolivet Y, Hasenfratz-Sauder MP, Orellano EG, da Guia Silva Lima M, Dizengremel P, Fernandes de Melo D. Alternative oxidase regulation in roots of Vigna unguiculata cultivars differing in drought/salt tolerance. JOURNAL OF PLANT PHYSIOLOGY 2007; 164:718-27. [PMID: 16716451 DOI: 10.1016/j.jplph.2006.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 04/05/2006] [Indexed: 05/09/2023]
Abstract
The alternative oxidase (Aox) was studied at different levels (transcript, protein and capacity) in response to an osmotic shock applied to roots of cowpea (Vigna unguiculata). Two cultivars of V. unguiculata were used, Vita 3 and Vita 5, tolerant and sensitive to drought/saline stress respectively. The seedlings (17-day-old) were grown in hydroponic conditions and submitted to NaCl (100 and 200 mM) or 200.67 g L(-1) PEG 6000 (iso-osmotic condition to 100 mM NaCl). The VuAox1 and VuAox2a mRNA were not detected in either cultivar under all tested conditions while the VuAox2b gene was differently expressed. In the tolerant cultivar (Vita 3), the expression of VuAox2b gene was stimulated by an osmotic stress induced by PEG which was associated with a higher amount and capacity of the Aox protein. In the same cultivar, this gene was under-expressed in salt stress conditions with poor effect on the protein level. In the sensitive cultivar (Vita 5), the transcript level of the VuAox2b was unchanged in response to PEG treatment, even though the protein and the capacity tended to increase. Upon salt stress, the VuAox2b gene was over-expressed. At 100mM NaCl, this VuAox2b gene over-expression led to a higher amount and capacity of Aox. This effect was reduced at 200 mM NaCl. Overall, these results suggest complex mechanisms (transcriptional, translational and post-translational) for Aox regulation in response to osmotic stress.
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Affiliation(s)
- José Hélio Costa
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, P.O. Box 6029, 60455-760 Fortaleza Ceará, Brazil
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Ho LHM, Giraud E, Lister R, Thirkettle-Watts D, Low J, Clifton R, Howell KA, Carrie C, Donald T, Whelan J. Characterization of the regulatory and expression context of an alternative oxidase gene provides insights into cyanide-insensitive respiration during growth and development. PLANT PHYSIOLOGY 2007; 143:1519-33. [PMID: 17322330 PMCID: PMC1851840 DOI: 10.1104/pp.106.091819] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Accepted: 02/02/2007] [Indexed: 05/14/2023]
Abstract
Alternative oxidase (AOX) is encoded in small multigene families in plants. Functional analysis of the Arabidopsis (Arabidopsis thaliana) alternative oxidase 1c (AtAOX1c) promoter, an AOX gene not induced by oxidative stress, indicated that regulation of expression was complex, with the upstream promoter region containing positive and negative response regions. Comparison to the promoter region of soybean (Glycine max) alternative oxidase 2b (GmAOX2b), another AOX gene not induced by oxidative stress, revealed that they contained seven sequence elements in common. All elements were active in the promoter region of AtAOX1c in suspension cells and in leaf tissue from Columbia and mutant plants, where a mitochondrial protein import receptor was inactivated. Analysis of coexpressed and putatively coregulated genes, the latter defined as containing five or more sequence elements functional in AtAOX1c, indicated that AtAOX1c was coregulated with components involved with cell division and growth. Consistent with this analysis, we demonstrated that site II elements, previously shown to regulate the proliferating cell nuclear antigen, are present in the upstream promoter region of AtAOX1c and were strong negative regulators of AtAOX1c expression. It was demonstrated that NDB4, a gene encoding an external NAD(P)H dehydrogenase, displayed strong coexpression with AtAOX1c. Overall, these results indicate that AtAOX1c is regulated by growth and developmental signals.
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Affiliation(s)
- Lois H M Ho
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
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Li F, Zhang Y, Wang M, Zhang Y, Wu X, Guo X. Molecular cloning and expression characteristics of alternative oxidase gene of cotton (Gossypium hirsutum). Mol Biol Rep 2007; 35:97-105. [PMID: 17351819 DOI: 10.1007/s11033-007-9058-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Accepted: 01/17/2007] [Indexed: 10/23/2022]
Abstract
A novel alternative oxidase (AOX) gene derived from cotton (Gossypium hirsutum), designated as GhAOX1, was cloned with RACE-PCR. The full-length cDNA of GhAOX1was 1,298 bp in size, containing a 996 bp open reading frame (ORF) which corresponds to a precursor protein of 332 amino acid residues with a calculated molecular mass of 37.5 kDa. The predicted amino acid sequence exhibited 68.4%, 68.1%, 59.4%, and 69.8% homology to the alternative oxidases of Arabidopsis thaliana, Nicotiana tabacum, Solanum tuberosum and Glycine max, respectively. Interestingly, striking similarity in several coding regions, such as metal binding and hydrophobic alpha-helix regions was seen between GhAOX1 and other AOX1 proteins. Analysis of the exon/intron structure of the GhAOX1 gene showed that GhAOX1 consisted of four exons and three introns. Southern analysis indicated that the GhAOX1 was a single copy gene belonging to a multi-gene family. Expression analysis by Northern blot revealed that the GhAOX1 exhibited preferential expression in tissues, with the higher expression being found in cotyledons and petals. GhAOX1 was also found to be induced by a variety of stresses stimulation including cold, citrate, SA, KCN and antimycin A in cotton.
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Affiliation(s)
- Fang Li
- Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, 271018, Taian, Shandong, China
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Fujii S, Komatsu S, Toriyama K. Retrograde regulation of nuclear gene expression in CW-CMS of rice. PLANT MOLECULAR BIOLOGY 2007; 63:405-17. [PMID: 17086445 DOI: 10.1007/s11103-006-9097-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Accepted: 10/05/2006] [Indexed: 05/12/2023]
Abstract
The CW-cytoplasmic male sterility (CMS) line has the cytoplasm of Oryza rufipogon Griff, and mature pollen is morphologically normal under an optical microscope but lacks the ability to germinate; restorer gene Rf17 has been identified as restoring this ability. The difference between nuclear gene expression in mature anthers was compared for the CW-CMS line, [cms-CW] rf17rf17, and a maintainer line with normal cytoplasm of Oryza sativa L., [normal] rf17rf17. Using a 22-k rice oligoarray we detected 58 genes that were up-regulated more than threefold in the CW-CMS line. Expression in other organs was further investigated for 20 genes using RT-PCR. Five genes, including genes for alternative oxidase, were found to be preferentially expressed in [cms-CW] rf17rf17 but not in [normal] rf17rf17 or [cms-CW] Rf17Rf17. Such [cms-CW] rf17rf17-specific gene expression was only observed in mature anthers but not in leaves, stems, or roots, indicating the presence of anther-specific mitochondrial retrograde regulation of nuclear gene expression, and that Rf17 has a role in restoring the ectopic gene expression. We also used a proteomic approach to discover the retrograde regulated proteins and identified six proteins that were accumulated differently. These results reveal organ-specific induced mitochondrial retrograde pathways affecting nuclear gene expression possibly related to CMS.
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Affiliation(s)
- Sota Fujii
- Laboratory of Environmental Biotechnology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
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