1
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Kinet R, Richelle A, Colle M, Demaegd D, von Stosch M, Sanders M, Sehrt H, Delvigne F, Goffin P. Giving the cells what they need when they need it: Biosensor-based feeding control. Biotechnol Bioeng 2024; 121:1271-1283. [PMID: 38258490 DOI: 10.1002/bit.28657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 12/11/2023] [Accepted: 01/04/2024] [Indexed: 01/24/2024]
Abstract
"Giving the cells exactly what they need, when they need it" is the core idea behind the proposed bioprocess control strategy: operating bioprocess based on the physiological behavior of the microbial population rather than exclusive monitoring of environmental parameters. We are envisioning to achieve this through the use of genetically encoded biosensors combined with online flow cytometry (FCM) to obtain a time-dependent "physiological fingerprint" of the population. We developed a biosensor based on the glnA promoter (glnAp) and applied it for monitoring the nitrogen-related nutritional state of Escherichia coli. The functionality of the biosensor was demonstrated through multiple cultivation runs performed at various scales-from microplate to 20 L bioreactor. We also developed a fully automated bioreactor-FCM interface for on-line monitoring of the microbial population. Finally, we validated the proposed strategy by performing a fed-batch experiment where the biosensor signal is used as the actuator for a nitrogen feeding feedback control. This new generation of process control, -based on the specific needs of the cells, -opens the possibility of improving process development on a short timescale and therewith, the robustness and performance of fermentation processes.
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Affiliation(s)
| | | | | | | | | | | | - Hannah Sehrt
- TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Frank Delvigne
- TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Philippe Goffin
- Molecular and Cellular Biology, University of Brussels, Brussels, Belgium
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2
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Ľuptáková E, Vigouroux A, Končitíková R, Kopečná M, Zalabák D, Novák O, Salcedo Sarmiento S, Ćavar Zeljković S, Kopečný DJ, von Schwartzenberg K, Strnad M, Spíchal L, De Diego N, Kopečný D, Moréra S. Plant nucleoside N-ribohydrolases: riboside binding and role in nitrogen storage mobilization. Plant J 2024; 117:1432-1452. [PMID: 38044809 DOI: 10.1111/tpj.16572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 11/16/2023] [Accepted: 11/20/2023] [Indexed: 12/05/2023]
Abstract
Cells save their energy during nitrogen starvation by selective autophagy of ribosomes and degradation of RNA to ribonucleotides and nucleosides. Nucleosides are hydrolyzed by nucleoside N-ribohydrolases (nucleosidases, NRHs). Subclass I of NRHs preferentially hydrolyzes the purine ribosides while subclass II is more active towards uridine and xanthosine. Here, we performed a crystallographic and kinetic study to shed light on nucleoside preferences among plant NRHs followed by in vivo metabolomic and phenotyping analyses to reveal the consequences of enhanced nucleoside breakdown. We report the crystal structure of Zea mays NRH2b (subclass II) and NRH3 (subclass I) in complexes with the substrate analog forodesine. Purine and pyrimidine catabolism are inseparable because nucleobase binding in the active site of ZmNRH is mediated via a water network and is thus unspecific. Dexamethasone-inducible ZmNRH overexpressor lines of Arabidopsis thaliana, as well as double nrh knockout lines of moss Physcomitrium patents, reveal a fine control of adenosine in contrast to other ribosides. ZmNRH overexpressor lines display an accelerated early vegetative phase including faster root and rosette growth upon nitrogen starvation or osmotic stress. Moreover, the lines enter the bolting and flowering phase much earlier. We observe changes in the pathways related to nitrogen-containing compounds such as β-alanine and several polyamines, which allow plants to reprogram their metabolism to escape stress. Taken together, crop plant breeding targeting enhanced NRH-mediated nitrogen recycling could therefore be a strategy to enhance plant growth tolerance and productivity under adverse growth conditions.
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Affiliation(s)
- Eva Ľuptáková
- Department of Experimental Biology, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic
| | - Armelle Vigouroux
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, F-91198, France
| | - Radka Končitíková
- Department of Experimental Biology, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic
| | - Martina Kopečná
- Department of Experimental Biology, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic
| | - David Zalabák
- Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences & Palacký University, Šlechtitelů 11, Olomouc, CZ-78371, Czech Republic
| | - Ondřej Novák
- Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences & Palacký University, Šlechtitelů 11, Olomouc, CZ-78371, Czech Republic
| | - Sara Salcedo Sarmiento
- Czech Advanced Technology and Research Institute, Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Sanja Ćavar Zeljković
- Czech Advanced Technology and Research Institute, Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Genetic Resources for Vegetables, Medicinal and Special Plants, Crop Research Institute, Šlechtitelů 29, 78371, Olomouc, Czech Republic
| | - David Jaroslav Kopečný
- Department of Experimental Biology, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic
| | - Klaus von Schwartzenberg
- Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences & Palacký University, Šlechtitelů 11, Olomouc, CZ-78371, Czech Republic
| | - Lukáš Spíchal
- Czech Advanced Technology and Research Institute, Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Nuria De Diego
- Czech Advanced Technology and Research Institute, Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - David Kopečný
- Department of Experimental Biology, Faculty of Science, Palacký University, Olomouc, CZ-78371, Czech Republic
| | - Solange Moréra
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, F-91198, France
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3
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Jiang M, Song Y, Yang R, Zheng C, Zheng Y, Zhang H, Li S, Tan Y, Huang J, Shu Q, Li R. Melatonin activates the OsbZIP79-OsABI5 module that orchestrates nitrogen and ROS homeostasis to alleviate nitrogen-limitation stress in rice. Plant Commun 2023; 4:100674. [PMID: 37598294 PMCID: PMC10721462 DOI: 10.1016/j.xplc.2023.100674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/09/2023] [Accepted: 08/16/2023] [Indexed: 08/21/2023]
Abstract
Melatonin (Mel) has previously been reported to effectively alleviate nitrogen-limitation (N-L) stress and thus increase nitrogen-use efficiency (NUE) in several plants, but the underlying mechanism remains obscure. Here, we revealed that OsbZIP79 (BASIC LEUCINE ZIPPER 79) is transcriptionally activated under N-L conditions, and its expression is further enhanced by exogenous Mel. By the combined use of omics, genetics, and biological techniques, we revealed that the OsbZIP79-OsABI5 (ABSCISIC ACID INSENSITIVE 5) module stimulated regulation of reactive oxygen species (ROS) homeostasis and the uptake and metabolism of nitrogen under conditions of indoor nitrogen limitation (1/16 normal level). OsbZIP79 activated the transcription of OsABI5, and OsABI5 then bound to the promoters of target genes, including genes involved in ROS homeostasis and nitrogen metabolism, activating their transcription. This module was also indispensable for upregulation of several other genes involved in abscisic acid catabolism, nitrogen uptake, and assimilation under N-L and Mel treatment, although these genes were not directly transactivated by OsABI5. Field experiments demonstrated that Mel significantly improved rice growth under low nitrogen (L-N, half the normal level) by the same mechanism revealed in the nitrogen-limitation study. Mel application produced a 28.6% yield increase under L-N and thus similar increases in NUE. Also, two OsbZIP79-overexpression lines grown in L-N field plots had significantly higher NUE (+13.7% and +21.2%) than their wild types. Together, our data show that an OsbZIP79-OsABI5 module regulates the rice response to N insufficiency (N limitation or low N), which is important for increasing NUE in rice production.
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Affiliation(s)
- Meng Jiang
- Hainan Institute, Zhejiang University, Yazhou Bay Sci-Tech City, Sanya, China; National Key Laboratory of Rice Breeding and Biology and Zhejiang Provincial Key Laboratory of Crop Germplasm, The Advanced Seed Institute, Zhejiang University, Hangzhou, China
| | - Yue Song
- Hainan Institute, Zhejiang University, Yazhou Bay Sci-Tech City, Sanya, China; National Key Laboratory of Rice Breeding and Biology and Zhejiang Provincial Key Laboratory of Crop Germplasm, The Advanced Seed Institute, Zhejiang University, Hangzhou, China
| | - Ruifang Yang
- Crop Breeding and Cultivation Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Chenfan Zheng
- Hainan Institute, Zhejiang University, Yazhou Bay Sci-Tech City, Sanya, China; National Key Laboratory of Rice Breeding and Biology and Zhejiang Provincial Key Laboratory of Crop Germplasm, The Advanced Seed Institute, Zhejiang University, Hangzhou, China
| | - Yunchao Zheng
- School of Life Sciences, Westlake University, Hangzhou, China
| | - Huali Zhang
- State Key Laboratory of Rice Breeding and Biology and Chinese National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, China
| | - Shan Li
- National Key Laboratory of Rice Breeding and Biology and Zhejiang Provincial Key Laboratory of Crop Germplasm, The Advanced Seed Institute, Zhejiang University, Hangzhou, China
| | - Yuanyuan Tan
- National Key Laboratory of Rice Breeding and Biology and Zhejiang Provincial Key Laboratory of Crop Germplasm, The Advanced Seed Institute, Zhejiang University, Hangzhou, China
| | - Jianzhong Huang
- Hainan Institute, Zhejiang University, Yazhou Bay Sci-Tech City, Sanya, China
| | - Qingyao Shu
- Hainan Institute, Zhejiang University, Yazhou Bay Sci-Tech City, Sanya, China; National Key Laboratory of Rice Breeding and Biology and Zhejiang Provincial Key Laboratory of Crop Germplasm, The Advanced Seed Institute, Zhejiang University, Hangzhou, China.
| | - Ruiqing Li
- College of Agronomy, Anhui Agricultural University, Hefei, China.
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Cruz-Leite VRM, Moreira ALE, Silva LOS, Inácio MM, Parente-Rocha JA, Ruiz OH, Weber SS, Soares CMDA, Borges CL. Proteomics of Paracoccidioides lutzii: Overview of Changes Triggered by Nitrogen Catabolite Repression. J Fungi (Basel) 2023; 9:1102. [PMID: 37998907 PMCID: PMC10672198 DOI: 10.3390/jof9111102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/06/2023] [Accepted: 11/08/2023] [Indexed: 11/25/2023] Open
Abstract
Members of the Paracoccidioides complex are the causative agents of Paracoccidioidomycosis (PCM), a human systemic mycosis endemic in Latin America. Upon initial contact with the host, the pathogen needs to uptake micronutrients. Nitrogen is an essential source for biosynthetic pathways. Adaptation to nutritional stress is a key feature of fungi in host tissues. Fungi utilize nitrogen sources through Nitrogen Catabolite Repression (NCR). NCR ensures the scavenging, uptake and catabolism of alternative nitrogen sources, when preferential ones, such as glutamine or ammonium, are unavailable. The NanoUPLC-MSE proteomic approach was used to investigate the NCR response of Paracoccidioides lutzii after growth on proline or glutamine as a nitrogen source. A total of 338 differentially expressed proteins were identified. P. lutzii demonstrated that gluconeogenesis, β-oxidation, glyoxylate cycle, adhesin-like proteins, stress response and cell wall remodeling were triggered in NCR-proline conditions. In addition, within macrophages, yeast cells trained under NCR-proline conditions showed an increased ability to survive. In general, this study allows a comprehensive understanding of the NCR response employed by the fungus to overcome nutritional starvation, which in the human host is represented by nutritional immunity. In turn, the pathogen requires rapid adaptation to the changing microenvironment induced by macrophages to achieve successful infection.
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Affiliation(s)
- Vanessa Rafaela Milhomem Cruz-Leite
- Department of Biochemistry and Molecular Biology, Institute of Biological Sciences II, Federal University of Goiás, Goiânia 74690-900, GO, Brazil; (A.L.E.M.); (L.O.S.S.); (M.M.I.); (J.A.P.-R.); (C.M.d.A.S.)
| | - André Luís Elias Moreira
- Department of Biochemistry and Molecular Biology, Institute of Biological Sciences II, Federal University of Goiás, Goiânia 74690-900, GO, Brazil; (A.L.E.M.); (L.O.S.S.); (M.M.I.); (J.A.P.-R.); (C.M.d.A.S.)
| | - Lana O’Hara Souza Silva
- Department of Biochemistry and Molecular Biology, Institute of Biological Sciences II, Federal University of Goiás, Goiânia 74690-900, GO, Brazil; (A.L.E.M.); (L.O.S.S.); (M.M.I.); (J.A.P.-R.); (C.M.d.A.S.)
| | - Moises Morais Inácio
- Department of Biochemistry and Molecular Biology, Institute of Biological Sciences II, Federal University of Goiás, Goiânia 74690-900, GO, Brazil; (A.L.E.M.); (L.O.S.S.); (M.M.I.); (J.A.P.-R.); (C.M.d.A.S.)
- Estácio de Goiás University Center—FESGO, Goiânia 74063-010, GO, Brazil
| | - Juliana Alves Parente-Rocha
- Department of Biochemistry and Molecular Biology, Institute of Biological Sciences II, Federal University of Goiás, Goiânia 74690-900, GO, Brazil; (A.L.E.M.); (L.O.S.S.); (M.M.I.); (J.A.P.-R.); (C.M.d.A.S.)
| | - Orville Hernandez Ruiz
- MICROBA Research Group, Cellular and Molecular Biology Unit, Department of Microbiology, School of Microbiology, University of Antioquia, Medellín 050010, Colombia;
| | - Simone Schneider Weber
- Faculty of Pharmaceutical Sciences, Food and Nutrition, Federal University of Mato Grosso do Sul, Campo Grande 79304-902, MS, Brazil;
| | - Célia Maria de Almeida Soares
- Department of Biochemistry and Molecular Biology, Institute of Biological Sciences II, Federal University of Goiás, Goiânia 74690-900, GO, Brazil; (A.L.E.M.); (L.O.S.S.); (M.M.I.); (J.A.P.-R.); (C.M.d.A.S.)
| | - Clayton Luiz Borges
- Department of Biochemistry and Molecular Biology, Institute of Biological Sciences II, Federal University of Goiás, Goiânia 74690-900, GO, Brazil; (A.L.E.M.); (L.O.S.S.); (M.M.I.); (J.A.P.-R.); (C.M.d.A.S.)
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5
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Scholz SS, Barth E, Clément G, Marmagne A, Ludwig-Müller J, Sakakibara H, Kiba T, Vicente-Carbajosa J, Pollmann S, Krapp A, Oelmüller R. The Root-Colonizing Endophyte Piriformospora indica Supports Nitrogen-Starved Arabidopsis thaliana Seedlings with Nitrogen Metabolites. Int J Mol Sci 2023; 24:15372. [PMID: 37895051 PMCID: PMC10607921 DOI: 10.3390/ijms242015372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
The root-colonizing endophytic fungus Piriformospora indica promotes the root and shoot growth of its host plants. We show that the growth promotion of Arabidopsis thaliana leaves is abolished when the seedlings are grown on media with nitrogen (N) limitation. The fungus neither stimulated the total N content nor did it promote 15NO3- uptake from agar plates to the leaves of the host under N-sufficient or N-limiting conditions. However, when the roots were co-cultivated with 15N-labelled P. indica, more labels were detected in the leaves of N-starved host plants but not in plants supplied with sufficient N. Amino acid and primary metabolite profiles, as well as the expression analyses of N metabolite transporter genes suggest that the fungus alleviates the adaptation of its host from the N limitation condition. P. indica alters the expression of transporter genes, which participate in the relocation of NO3-, NH4+ and N metabolites from the roots to the leaves under N limitation. We propose that P. indica participates in the plant's metabolomic adaptation against N limitation by delivering reduced N metabolites to the host, thus alleviating metabolic N starvation responses and reprogramming the expression of N metabolism-related genes.
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Affiliation(s)
- Sandra S. Scholz
- Department of Plant Physiology, Matthias-Schleiden-Institute, Friedrich-Schiller-University Jena, 07743 Jena, Germany;
| | - Emanuel Barth
- Bioinformatics Core Facility, Friedrich-Schiller-University Jena, 07743 Jena, Germany;
| | - Gilles Clément
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France (A.M.); (A.K.)
| | - Anne Marmagne
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France (A.M.); (A.K.)
| | - Jutta Ludwig-Müller
- Institute of Botany, Technische Universität Dresden, 01217 Dresden, Germany;
| | - Hitoshi Sakakibara
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan; (H.S.); (T.K.)
| | - Takatoshi Kiba
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan; (H.S.); (T.K.)
| | - Jesús Vicente-Carbajosa
- Centro de Biotechnología y Genómica de Plantas, Instituto Nacional de Investigación y Tecnología Agraria y Alimentación (INIA), Universidad Politécnica de Madrid (UPM), Campus de Montegancedo, 28223 Madrid, Spain; (J.V.-C.); (S.P.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Stephan Pollmann
- Centro de Biotechnología y Genómica de Plantas, Instituto Nacional de Investigación y Tecnología Agraria y Alimentación (INIA), Universidad Politécnica de Madrid (UPM), Campus de Montegancedo, 28223 Madrid, Spain; (J.V.-C.); (S.P.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Anne Krapp
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France (A.M.); (A.K.)
| | - Ralf Oelmüller
- Department of Plant Physiology, Matthias-Schleiden-Institute, Friedrich-Schiller-University Jena, 07743 Jena, Germany;
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6
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Huang S, Zhang X, Song Z, Rahman MU, Fan B. Transcriptional Profiling and Transposon Mutagenesis Study of the Endophyte Pantoea eucalypti FBS135 Adapting to Nitrogen Starvation. Int J Mol Sci 2023; 24:14282. [PMID: 37762583 PMCID: PMC10532344 DOI: 10.3390/ijms241814282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/12/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
The research on plant endophytes has been drawing a lot of attention in recent years. Pantoea belongs to a group of endophytes with plant growth-promoting activity and has been widely used in agricultural fields. In our earlier studies, Pantoea eucalypti FBS135 was isolated from healthy-growing Pinus massoniana and was able to promote pine growth. P. eucalypti FBS135 can grow under extremely low nitrogen conditions. To understand the mechanism of the low-nitrogen tolerance of this bacterium, the transcriptome of FBS135 in the absence of nitrogen was examined in this study. We found that FBS135 actively regulates its gene expression in response to nitrogen deficiency. Nearly half of the number (4475) of genes in FBS135 were differentially expressed under this condition, mostly downregulated, while it significantly upregulated many transportation-associated genes and some nitrogen metabolism-related genes. In the downregulated genes, the ribosome pathway-related ones were significantly enriched. Meanwhile, we constructed a Tn5 transposon library of FBS135, from which four genes involved in low-nitrogen tolerance were screened out, including the gene for the host-specific protein J, RNA polymerase σ factor RpoS, phosphoribosamine-glycine ligase, and serine acetyltransferase. Functional analysis of the genes revealed their potential roles in the adaptation to nitrogen limitation. The results obtained in this work shed light on the mechanism of endophytes represented by P. eucalypti FBS135, at the overall transcriptional level, to an environmentally limited nitrogen supply and provided a basis for further investigation on this topic.
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Affiliation(s)
- Shengquan Huang
- Department of Forestry, Nanjing Forestry University, Nanjing 210037, China (M.U.R.)
| | - Xiuyu Zhang
- Department of Biology and Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Zongwen Song
- Department of Forestry, Nanjing Forestry University, Nanjing 210037, China (M.U.R.)
| | - Mati Ur Rahman
- Department of Forestry, Nanjing Forestry University, Nanjing 210037, China (M.U.R.)
| | - Ben Fan
- Department of Forestry, Nanjing Forestry University, Nanjing 210037, China (M.U.R.)
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7
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Shi Y, Yu B, Cheng S, Hu W, Liu F. The Change in Whole-Genome Methylation and Transcriptome Profile under Autophagy Defect and Nitrogen Starvation. Int J Mol Sci 2023; 24:14047. [PMID: 37762347 PMCID: PMC10530911 DOI: 10.3390/ijms241814047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/10/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
Through whole-genome bisulfite sequencing and RNA-seq, we determined the potential impact of autophagy in regulating DNA methylation in Arabidopsis, providing a solid foundation for further understanding the molecular mechanism of autophagy and how plants cope with nitrogen deficiency. A total of 335 notable differentially expressed genes (DEGs) were discovered in wild-type Arabidopsis (Col-0-N) and an autophagic mutant cultivated under nitrogen starvation (atg5-1-N). Among these, 142 DEGs were associated with hypomethylated regions (hypo-DMRs) and were upregulated. This suggests a correlation between DNA demethylation and the ability of Arabidopsis to cope with nitrogen deficiency. Examination of the hypo-DMR-linked upregulated DEGs indicated that the expression of MYB101, an ABA pathway regulator, may be regulated by DNA demethylation and the recruitment of transcription factors (TFs; ERF57, ERF105, ERF48, and ERF111), which may contribute to the growth arrest induced by abscisic acid (ABA). Additionally, we found that DNA methylation might impact the biosynthesis of salicylic acid (SA). The promoter region of ATGH3.12 (PBS3), a key enzyme in SA synthesis, was hypomethylated, combined with overexpression of PBS3 and its potential TF AT3G46070, suggesting that autophagy defects may lead to SA-activated senescence, depending on DNA demethylation. These findings suggest that DNA hypomethylation may impact the mechanism by which Arabidopsis autophagy mutants (atg5-1) respond to nitrogen deficiency, specifically in relation to ABA and SA regulation. Our evaluation of hormone levels verified that these two hormones are significantly enriched under nitrogen deficiency in atg5-1-N compared to Col-0-N.
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Affiliation(s)
- Yunfeng Shi
- Lushan Botanical Garden, Jiangxi Province and Chinese Academy of Sciences, Jiujiang 332000, China; (Y.S.); (B.Y.); (S.C.)
| | - Baiyang Yu
- Lushan Botanical Garden, Jiangxi Province and Chinese Academy of Sciences, Jiujiang 332000, China; (Y.S.); (B.Y.); (S.C.)
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Shan Cheng
- Lushan Botanical Garden, Jiangxi Province and Chinese Academy of Sciences, Jiujiang 332000, China; (Y.S.); (B.Y.); (S.C.)
| | - Weiming Hu
- Lushan Botanical Garden, Jiangxi Province and Chinese Academy of Sciences, Jiujiang 332000, China; (Y.S.); (B.Y.); (S.C.)
| | - Fen Liu
- Lushan Botanical Garden, Jiangxi Province and Chinese Academy of Sciences, Jiujiang 332000, China; (Y.S.); (B.Y.); (S.C.)
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8
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Andriopoulos V, Kornaros M. LASSO Regression with Multiple Imputations for the Selection of Key Variables Affecting the Fatty Acid Profile of Nannochloropsis oculata. Mar Drugs 2023; 21:483. [PMID: 37755096 PMCID: PMC10533012 DOI: 10.3390/md21090483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 08/28/2023] [Accepted: 08/31/2023] [Indexed: 09/28/2023] Open
Abstract
The marine microalga Nannochloropsis oculata has garnered significant interest as a potential source of lipids, both for biofuel and nutrition, containing significant amounts of C16:0, C16:1, and C20:5, n-3 (EPA) fatty acids (FA). Growth parameters such as temperature, pH, light intensity, and nutrient availability play a crucial role in the fatty acid profile of microalgae, with N. oculata being no exception. This study aims to identify key variables for the FA profile of N. oculata grown autotrophically. To that end, the most relevant literature data were gathered and combined with our previous work as well as with novel experimental data, with 121 observations in total. The examined variables were the percentages of C14:0, C16:0, C16:1, C18:1, C18:2, and C20:5, n-3 in total FAs, their respective ratios to C16:0, and the respective content of biomass in those fatty acids in terms of ash free dry weight. Many potential predictor variables were collected, while dummy variables were introduced to account for bias in the measured variables originating from different authors as well as for other parameters. The method of multiple imputations was chosen to handle missing data, with limits based on the literature and model-based estimation, such as using the software PHREEQC and residual modelling for the estimation of pH. To eliminate unimportant predictor variables, LASSO (Least Absolute Shrinkage and Selection Operator) regression analysis with a novel definition of optimal lambda was employed. LASSO regression identified the most relevant predictors while minimizing the risk of overfitting the model. Subsequently, stepwise linear regression with interaction terms was used to further study the effects of the selected predictors. After two rounds of regression, sparse refined models were acquired, and their coefficients were evaluated based on significance. Our analysis confirms well-known effects, such as that of temperature, and it uncovers novel unreported effects of aeration, calcium, magnesium, and manganese. Of special interest is the negative effect of aeration on polyunsaturated fatty acids (PUFAs), which is possibly related to the enzymatic kinetics of fatty acid desaturation under increased oxygen concentration. These findings contribute to the optimization of the fatty acid profile of N. oculata for different purposes, such as production of, high in PUFAs, food or feed, or production of, high in saturated and monounsaturated FA methyl esters (FAME), biofuels.
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Affiliation(s)
- Vasilis Andriopoulos
- Laboratory of Biochemical Engineering & Environmental Technology (LBEET), Department of Chemical Engineering, University of Patras, 26504 Patras, Greece;
- Institute of Circular Economy and Environment (ICEE), University of Patras’ Research and Development Center, 26504 Patras, Greece
| | - Michael Kornaros
- Laboratory of Biochemical Engineering & Environmental Technology (LBEET), Department of Chemical Engineering, University of Patras, 26504 Patras, Greece;
- Institute of Circular Economy and Environment (ICEE), University of Patras’ Research and Development Center, 26504 Patras, Greece
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9
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Lee Y, Kim B, Jang HS, Huh WK. Atg1-dependent phosphorylation of Vps34 is required for dynamic regulation of the phagophore assembly site and autophagy in Saccharomyces cerevisiae. Autophagy 2023; 19:2428-2442. [PMID: 36803233 PMCID: PMC10392759 DOI: 10.1080/15548627.2023.2182478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 02/13/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
Macroautophagy/autophagy is a key catabolic pathway in which double-membrane autophagosomes sequester various substrates destined for degradation, enabling cells to maintain homeostasis and survive under stressful conditions. Several autophagy-related (Atg) proteins are recruited to the phagophore assembly site (PAS) and cooperatively function to generate autophagosomes. Vps34 is a class III phosphatidylinositol 3-kinase, and Atg14-containing Vps34 complex I plays essential roles in autophagosome formation. However, the regulatory mechanisms of yeast Vps34 complex I are still poorly understood. Here, we demonstrate that Atg1-dependent phosphorylation of Vps34 is required for robust autophagy activity in Saccharomyces cerevisiae. Following nitrogen starvation, Vps34 in complex I is selectively phosphorylated on multiple serine/threonine residues in its helical domain. This phosphorylation is important for full autophagy activation and cell survival. The absence of Atg1 or its kinase activity leads to complete loss of Vps34 phosphorylation in vivo, and Atg1 directly phosphorylates Vps34 in vitro, regardless of its complex association type. We also demonstrate that the localization of Vps34 complex I to the PAS provides a molecular basis for the complex I-specific phosphorylation of Vps34. This phosphorylation is required for the normal dynamics of Atg18 and Atg8 at the PAS. Together, our results reveal a novel regulatory mechanism of yeast Vps34 complex I and provide new insights into the Atg1-dependent dynamic regulation of the PAS.Abbreviations: ATG: autophagy-related; BARA: the repeated, autophagy-specific Co-IP: co-immunoprecipitation; GFP: green fluorescent protein; IP-MS: immunoprecipitation followed by tandem mass spectrometry; NTD: the N-terminal domain; PAS: phagophore assembly site; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns3K: phosphatidylinositol 3-kinase; SUR: structurally uncharacterized region; Vps34[KD]: Vps34D731N.
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Affiliation(s)
- Yongook Lee
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Bongkeun Kim
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Hae-Soo Jang
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Won-Ki Huh
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- Institute of Microbiology, Seoul National University, Seoul, Republic of Korea
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10
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Lin C, Guo X, Yu X, Li S, Li W, Yu X, An F, Zhao P, Ruan M. Genome-Wide Survey of the RWP-RK Gene Family in Cassava ( Manihot esculenta Crantz) and Functional Analysis. Int J Mol Sci 2023; 24:12925. [PMID: 37629106 PMCID: PMC10454212 DOI: 10.3390/ijms241612925] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/12/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023] Open
Abstract
The plant-specific RWP-RK transcription factor family plays a central role in the regulation of nitrogen response and gametophyte development. However, little information is available regarding the evolutionary relationships and characteristics of the RWP-RK family genes in cassava, an important tropical crop. Herein, 13 RWP-RK proteins identified in cassava were unevenly distributed across 9 of the 18 chromosomes (Chr), and these proteins were divided into two clusters based on their phylogenetic distance. The NLP subfamily contained seven cassava proteins including GAF, RWP-RK, and PB1 domains; the RKD subfamily contained six cassava proteins including the RWP-RK domain. Genes of the NLP subfamily had a longer sequence and more introns than the RKD subfamily. A large number of hormone- and stress-related cis-acting elements were found in the analysis of RWP-RK promoters. Real-time quantitative PCR revealed that all MeNLP1-7 and MeRKD1/3/5 genes responded to different abiotic stressors (water deficit, cold temperature, mannitol, polyethylene glycol, NaCl, and H2O2), hormonal treatments (abscisic acid and methyl jasmonate), and nitrogen starvation. MeNLP3/4/5/6/7 and MeRKD3/5, which can quickly and efficiently respond to different stresses, were found to be important candidate genes for further functional assays in cassava. The MeRKD5 and MeNLP6 proteins were localized to the cell nucleus in tobacco leaf. Five and one candidate proteins interacting with MeRKD5 and MeNLP6, respectively, were screened from the cassava nitrogen starvation library, including agamous-like mads-box protein AGL14, metallothionein 2, Zine finger FYVE domain containing protein, glyceraldehyde-3-phosphate dehydrogenase, E3 Ubiquitin-protein ligase HUWE1, and PPR repeat family protein. These results provided a solid basis to understand abiotic stress responses and signal transduction mediated by RWP-RK genes in cassava.
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Affiliation(s)
- Chenyu Lin
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (C.L.); (X.G.); (X.Y.)
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (S.L.); (W.L.); (X.Y.)
| | - Xin Guo
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (C.L.); (X.G.); (X.Y.)
| | - Xiaohui Yu
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (C.L.); (X.G.); (X.Y.)
| | - Shuxia Li
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (S.L.); (W.L.); (X.Y.)
| | - Wenbin Li
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (S.L.); (W.L.); (X.Y.)
| | - Xiaoling Yu
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (S.L.); (W.L.); (X.Y.)
| | - Feng An
- Hainan Danzhou Agro-Ecosystem National Observation and Research Station, Rubber Research Institute of Chinese Academy of Tropical Agricultural Sciences, Danzhou 571737, China;
| | - Pingjuan Zhao
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (S.L.); (W.L.); (X.Y.)
| | - Mengbin Ruan
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; (S.L.); (W.L.); (X.Y.)
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Murison V, Hérault J, Schoefs B, Marchand J, Ulmann L. Bioinformatics-Based Screening Approach for the Identification and Characterization of Lipolytic Enzymes from the Marine Diatom Phaeodactylum tricornutum. Mar Drugs 2023; 21:md21020125. [PMID: 36827166 PMCID: PMC9964374 DOI: 10.3390/md21020125] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/17/2023] Open
Abstract
Oleaginous diatoms accumulate lipids of biotechnological interest when exposed to nutrient stress conditions such as nitrogen starvation. While accumulation mechanisms are well-known and have been engineered to improve lipid production, degradation mechanisms remain poorly investigated in diatoms. Identifying lipid-degrading enzymes is the initial step to understanding the catabolic processes. In this study, an in silico screening of the genome of Phaeodactylum tricornutum led to the identification of 57 putative triacylglycerol lipases (EC 3.1.1.3) grouped in 4 families. Further analysis revealed the presence of conserved domains and catalytic residues of lipases. Physico-chemical characteristics and subcellular localization predictions highlighted that a majority of these putative proteins are hydrophilic and cytosolic, suggesting they could be recruited to lipid droplets directly from the cytosol. Among the 57 identified putative proteins, three lipases were identified as possibly involved in lipophagy due to a potential vacuolar localization. The expression of the mRNA corresponding to the 57 proteins was then searched in 3 transcriptomic datasets obtained under nitrogen starvation. Nine genes were highly regulated and were considered as encoding enzymes with a probable important function in lipid catabolism. A tertiary structure prediction of these nine candidates yielded eight functional 3D models. Among those, two downregulated enzymes, Phatr3_J54974 and Phatr3_EG00720, were highlighted as good targets for future functional genomics and purification studies to investigate their role in lipid degradation.
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Affiliation(s)
- Victor Murison
- BiOSSE, Biology of Organisms: Stress, Health, Environment, Département Génie Biologique, Institut Universitaire de Technologie, Le Mans Université, F-53020 Laval, France
| | - Josiane Hérault
- BiOSSE, Biology of Organisms: Stress, Health, Environment, Département Génie Biologique, Institut Universitaire de Technologie, Le Mans Université, F-53020 Laval, France
| | - Benoît Schoefs
- BiOSSE, Biology of Organisms: Stress, Health, Environment, UFR Sciences et Techniques, Le Mans Université, F-72085 Le Mans, France
| | - Justine Marchand
- BiOSSE, Biology of Organisms: Stress, Health, Environment, UFR Sciences et Techniques, Le Mans Université, F-72085 Le Mans, France
| | - Lionel Ulmann
- BiOSSE, Biology of Organisms: Stress, Health, Environment, Département Génie Biologique, Institut Universitaire de Technologie, Le Mans Université, F-53020 Laval, France
- Correspondence:
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Yin Z, Zhang Z, Lei Y, Klionsky DJ. Bidirectional roles of the Ccr4-Not complex in regulating autophagy before and after nitrogen starvation. Autophagy 2023; 19:415-425. [PMID: 35167422 PMCID: PMC9851207 DOI: 10.1080/15548627.2022.2036476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 01/12/2022] [Accepted: 01/28/2022] [Indexed: 01/22/2023] Open
Abstract
Macroautophagy/autophagy is a highly conserved catabolic process by which cytoplasmic constituents are delivered to the vacuole/lysosome for degradation and recycling. To maintain cellular homeostasis and prevent pathologies, the induction and amplitude of autophagy activity are finely controlled through regulation of ATG gene expression. Here we report that the Ccr4-Not complex in Saccharomyces cerevisiae has bidirectional roles in regulating autophagy before and after nutrient deprivation. Under nutrient-rich conditions, Ccr4-Not directly targets the mRNAs of several ATG genes in the core autophagy machinery to promote their degradation through deadenylation, thus contributing to maintaining autophagy at the basal level. Upon starvation, Ccr4-Not releases its repression of these ATG genes and switches its role to promote the expression of a different subset of ATG genes, which is required for sufficient autophagy induction and activity. These results reveal that the Ccr4-Not complex is indispensable to maintain autophagy at the appropriate amplitude in both basal and stress conditions.Abbreviations: AID, auxin-inducible degron; Ape1, aminopeptidase I; Atg, autophagy related; Cvt, cytoplasm-to-vacuole targeting; DMSO, dimethyl sulfoxide; IAA, indole-3-acetic acid; PA, protein A; RIP, RNA immunoprecipitation.
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Affiliation(s)
- Zhangyuan Yin
- Life Sciences Institute, and the Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Zhihai Zhang
- Life Sciences Institute, and the Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Yuchen Lei
- Life Sciences Institute, and the Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Daniel J. Klionsky
- Life Sciences Institute, and the Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
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13
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Kim JH, Ahn JW, Park EJ, Choi JI. Overexpression of S-Adenosylmethionine Synthetase in Recombinant Chlamydomonas for Enhanced Lipid Production. J Microbiol Biotechnol 2023; 33:310-318. [PMID: 36734134 PMCID: PMC10084756 DOI: 10.4014/jmb.2212.12009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 12/26/2022] [Accepted: 01/09/2023] [Indexed: 02/04/2023]
Abstract
Microalgae are attracting much attention as promising, eco-friendly producers of bioenergy due to their fast growth, absorption of carbon dioxide from the atmosphere, and production capacity in wastewater and salt water. However, microalgae can only accumulate large quantities of lipid in abiotic stress, which reduces productivity by decreasing cell growth. In this study, the strategy was investigated to increase cell viability and lipid production by overexpressing S-adenosylmethionine (SAM) synthetase (SAMS) in the microalga Chlamydomonas reinhardtii. SAM is a substance that plays an important role in various intracellular biochemical reactions, such as cell proliferation and stress response, and the overexpression of SAMS could allow cells to withstand the abiotic stress and increase productivity. Compared to wild-type C. reinhardtii, recombinant cells overexpressing SAMS grew 1.56-fold faster and produced 1.51-fold more lipids in a nitrogen-depleted medium. Furthermore, under saline-stress conditions, the survival rate and lipid accumulation were 1.56 and 2.04 times higher in the SAMS-overexpressing strain, respectively. These results suggest that the overexpression of SAMS in recombinant C. reinhardtii has high potential in the industrial-scale production of biofuels and various other high-value-added materials.
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Affiliation(s)
- Jeong Hyeon Kim
- Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Joon Woo Ahn
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 56212, Republic of Korea
| | - Eun-Jeong Park
- Aquatic Plant Variety Center, National Institute of Fisheries Science, Mokpo 58746, Republic of Korea
| | - Jong-Il Choi
- Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju 61186, Republic of Korea
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Chen R, Yamaoka Y, Feng Y, Chi Z, Xue S, Kong F. Co-Expression of Lipid Transporters Simultaneously Enhances Oil and Starch Accumulation in the Green Microalga Chlamydomonas reinhardtii under Nitrogen Starvation. Metabolites 2023; 13. [PMID: 36677040 DOI: 10.3390/metabo13010115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/31/2022] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
Lipid transporters synergistically contribute to oil accumulation under normal conditions in microalgae; however, their effects on lipid metabolism under stress conditions are unknown. Here, we examined the effect of the co-expression of lipid transporters, fatty acid transporters, (FAX1 and FAX2) and ABC transporter (ABCA2) on lipid metabolism and physiological changes in the green microalga Chlamydomonas under nitrogen (N) starvation. The results showed that the TAG content in FAX1-FAX2-ABCA2 over-expressor (OE) was 2.4-fold greater than in the parental line. Notably, in FAX1-FAX2-ABCA2-OE, the major membrane lipids and the starch and cellular biomass content also significantly increased compared with the control lines. Moreover, the expression levels of genes directly involved in TAG, fatty acid, and starch biosynthesis were upregulated. FAX1-FAX2-ABCA2-OE showed altered photosynthesis activity and increased ROS levels during nitrogen (N) deprivation. Our results indicated that FAX1-FAX2-ABCA2 overexpression not only enhanced cellular lipids but also improved starch and biomass contents under N starvation through modulation of lipid and starch metabolism and changes in photosynthesis activity. The strategy developed here could also be applied to other microalgae to produce FA-derived energy-rich and value-added compounds.
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15
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Maslać N, Sidhu C, Teeling H, Wagner T. Comparative Transcriptomics Sheds Light on Remodeling of Gene Expression during Diazotrophy in the Thermophilic Methanogen Methanothermococcus thermolithotrophicus. mBio 2022; 13:e0244322. [PMID: 36409126 DOI: 10.1128/mbio.02443-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Some marine thermophilic methanogens are able to perform energy-consuming nitrogen fixation despite deriving only little energy from hydrogenotrophic methanogenesis. We studied this process in Methanothermococcus thermolithotrophicus DSM 2095, a methanogenic archaeon of the order Methanococcales that contributes to the nitrogen pool in some marine environments. We successfully grew this archaeon under diazotrophic conditions in both batch and fermenter cultures, reaching the highest cell density reported so far. Diazotrophic growth depended strictly on molybdenum and, in contrast to other diazotrophs, was not inhibited by tungstate or vanadium. This suggests an elaborate control of metal uptake and a specific metal recognition system for the insertion into the nitrogenase cofactor. Differential transcriptomics of M. thermolithotrophicus grown under diazotrophic conditions with ammonium-fed cultures as controls revealed upregulation of the nitrogenase machinery, including chaperones, regulators, and molybdate importers, as well as simultaneous upregulation of an ammonium transporter and a putative pathway for nitrate and nitrite utilization. The organism thus employs multiple synergistic strategies for uptake of nitrogen nutrients during the early exponential growth phase without altering transcription levels for genes involved in methanogenesis. As a counterpart, genes coding for transcription and translation processes were downregulated, highlighting the maintenance of an intricate metabolic balance to deal with energy constraints and nutrient limitations imposed by diazotrophy. This switch in the metabolic balance included unexpected processes, such as upregulation of the CRISPR-Cas system, probably caused by drastic changes in transcription levels of putative mobile and virus-like elements. IMPORTANCE The thermophilic anaerobic archaeon M. thermolithotrophicus is a particularly suitable model organism to study the coupling of methanogenesis to diazotrophy. Likewise, its capability of simultaneously reducing N2 and CO2 into NH3 and CH4 with H2 makes it a viable target for biofuel production. We optimized M. thermolithotrophicus cultivation, resulting in considerably higher cell yields and enabling the successful establishment of N2-fixing bioreactors. Improved understanding of the N2 fixation process would provide novel insights into metabolic adaptations that allow this energy-limited extremophile to thrive under diazotrophy, for instance, by investigating its physiology and uncharacterized nitrogenase. We demonstrated that diazotrophic growth of M. thermolithotrophicus is exclusively dependent on molybdenum, and complementary transcriptomics corroborated the expression of the molybdenum nitrogenase system. Further analyses of differentially expressed genes during diazotrophy across three cultivation time points revealed insights into the response to nitrogen limitation and the coordination of core metabolic processes.
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Wang Y, Liu Y, Qu S, Liang W, Sun L, Ci D, Ren Z, Fan LM, Qian W. Nitrogen starvation induces genome-wide activation of transposable elements in Arabidopsis. J Integr Plant Biol 2022; 64:2374-2384. [PMID: 36178606 DOI: 10.1111/jipb.13376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Nitrogen (N) availability is a major limiting factor for plant growth and agricultural productivity. Although the gene regulation network in response to N starvation has been extensively studied, it remains unknown whether N starvation has an impact on the activity of transposable elements (TEs). Here, we report that TEs can be transcriptionally activated in Arabidopsis under N starvation conditions. Through genetic screening of idm1-14 suppressors, we cloned GLU1, which encodes a glutamate synthase that catalyzes the synthesis of glutamate in the primary N assimilation pathway. We found that glutamate synthase 1 (GLU1) and its functional homologs GLU2 and glutamate transport 1 (GLT1) are redundantly required for TE silencing, suggesting that N metabolism can regulate TE activity. Transcriptome and methylome analyses revealed that N starvation results in genome-wide TE activation without inducing obvious alteration of DNA methylation. Genetic analysis indicated that N starvation-induced TE activation is also independent of other well-established epigenetic mechanisms, including histone methylation and heterochromatin decondensation. Our results provide new insights into the regulation of TE activity under stressful environments in planta.
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Affiliation(s)
- Yue Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking University, Beijing, 100871, China
- School of Life Sciences, Peking University, Beijing, 100871, China
| | - Yi Liu
- School of Life Sciences, Peking University, Beijing, 100871, China
| | - Shaofeng Qu
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking University, Beijing, 100871, China
| | - Wenjie Liang
- School of Life Sciences, Peking University, Beijing, 100871, China
| | - Linhua Sun
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking University, Beijing, 100871, China
| | - Dong Ci
- Peking University Institute of Advanced Agricultural Sciences, Weifang, 261000, China
| | - Zhitong Ren
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking University, Beijing, 100871, China
| | - Liu-Min Fan
- School of Life Sciences, Peking University, Beijing, 100871, China
| | - Weiqiang Qian
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking University, Beijing, 100871, China
- Peking University Institute of Advanced Agricultural Sciences, Weifang, 261000, China
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Lupette J, Tardif M, Brugière S, Couté Y, Salvaing J, Maréchal E. Quantitative proteomic analyses reveal the impact of nitrogen starvation on the proteome of the model diatom Phaeodactylum tricornutum. Proteomics 2022; 22:e2200155. [PMID: 36168874 DOI: 10.1002/pmic.202200155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 12/29/2022]
Abstract
Diatoms are one of the largest groups in phytoplankton biodiversity. Understanding their response to nitrogen variations, present from micromolar to near-zero levels in oceans and fresh waters, is essential to comprehend their ecological success. Nitrogen starvation is used in biotechnological processes, to trigger the remodeling of carbon metabolism in the direction of fatty acids and triacylglycerol synthesis. We evaluated whole proteome changes in Phaeodactylum tricornutum after 7 days of cultivation with 5.5-mM nitrate (+N) or without any nitrogen source (-N). On a total of 3768 proteins detected in biological replicates, our analysis pointed to 384 differentially abundant proteins (DAP). Analysis of proteins of lower abundance in -N revealed an arrest of amino acid and protein syntheses, a remodeling of nitrogen metabolism, and a decrease of the proteasome abundance suggesting a decline in unselective whole-proteome decay. Analysis of proteins of higher abundance revealed the setting up of a general nitrogen scavenging system dependent on deaminases. The increase of a plastid palmitoyl-ACP desaturase appeared as a hallmark of carbon metabolism rewiring in the direction of fatty acid and triacylglycerol synthesis. This dataset is also valuable to select gene candidates for improved biotechnological properties.
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Affiliation(s)
- Josselin Lupette
- Laboratoire de Physiologie Cellulaire et Végétale, CEA, CNRS, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, Grenoble, France.,Laboratoire de Biogenèse Membranaire, CNRS, Université de Bordeaux, Villenave d'Ornon, France
| | - Marianne Tardif
- Université Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, CNRS, CEA, FR2048, Grenoble, France
| | - Sabine Brugière
- Université Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, CNRS, CEA, FR2048, Grenoble, France
| | - Yohann Couté
- Université Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, CNRS, CEA, FR2048, Grenoble, France
| | - Juliette Salvaing
- Laboratoire de Physiologie Cellulaire et Végétale, CEA, CNRS, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, Grenoble, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, CEA, CNRS, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, Grenoble, France
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Chatterjee P, Schafran P, Li FW, Meeks JC. Nostoc Talks Back: Temporal Patterns of Differential Gene Expression During Establishment of Anthoceros-Nostoc Symbiosis. Mol Plant Microbe Interact 2022; 35:917-932. [PMID: 35802132 DOI: 10.1094/mpmi-05-22-0101-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Endosymbiotic associations between hornworts and nitrogen-fixing cyanobacteria form when the plant is limited for combined nitrogen (N). We generated RNA-seq data to examine temporal gene expression patterns during the culturing of N-starved Anthoceros punctatus in the absence and the presence of symbiotic cyanobacterium Nostoc punctiforme. In symbiont-free A. punctatus gametophytes, N starvation caused downregulation of chlorophyll content and chlorophyll fluorescence characteristics as well as transcription of photosynthesis-related genes. This downregulation was reversed in A. punctatus cocultured with N. punctiforme, corresponding to the provision by the symbiont of N2-derived NH4+, which commenced within 5 days of coculture and reached a maximum by 14 days. We also observed transient increases in transcription of ammonium and nitrate transporters in a N. punctiforme-dependent manner as well as that of a SWEET transporter that was initially independent of N2-derived NH4+. The temporal patterns of differential gene expression indicated that N. punctiforme transmits signals that impact gene expression to A. punctatus both prior to and after its provision of fixed N. This study is the first illustrating the temporal patterns of gene expression during establishment of an endosymbiotic nitrogen-fixing association in this monophyletic evolutionary lineage of land plants. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Poulami Chatterjee
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, U.S.A
| | - Peter Schafran
- Boyce Thompson Institute, Ithaca, NY 14853, U.S.A
- Plant Biology Section, Cornell University, Ithaca, NY 14953, U.S.A
| | - Fay-Wei Li
- Boyce Thompson Institute, Ithaca, NY 14853, U.S.A
- Plant Biology Section, Cornell University, Ithaca, NY 14953, U.S.A
| | - John C Meeks
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, U.S.A
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Wang L, Li S, Sun L, Tong Y, Yang L, Zhu Y, Wang Y. Over-Expression of Phosphoserine Aminotransferase-Encoding Gene (AtPSAT1) Prompts Starch Accumulation in L. turionifera under Nitrogen Starvation. Int J Mol Sci 2022; 23:11563. [PMID: 36232863 DOI: 10.3390/ijms231911563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 11/17/2022] Open
Abstract
It has been demonstrated that the phosphorylation pathway of L-serine (Ser) biosynthesis (PPSB) is very important in plant growth and development, but whether and how PPSB affects nitrogen metabolism and starch accumulation has not been fully elucidated. In this study, we took the energy plant duckweed (strain Lemna turionifera 5511) as the research object and used a stable genetic transformation system to heterologously over-expressing Arabidopsis AtPSAT1 (the gene encoding phosphoserine aminotransferase, the second enzyme of PPSB). Our results showed that, under nitrogen starvation, the transgenic plants grew faster, with higher values of Fv/Fm, rETR, and Y(II), as well as fresh and dry weight, than the wild-type. More promisingly, the accumulation of starch was also found to be significantly improved when over-expressing AtPSAT1 in the transgenic plants. qRT-PCR analysis results showed that the expression of genes related to nitrogen assimilation, carbon metabolism, and starch biosynthesis was up-regulated, while the expression of starch degradation-related genes was down-regulated by AtPSAT1 over-expression. We propose that the increased starch accumulation caused by AtPSAT1 over-expression may result from both elevated photosynthetic capacity and nitrogen utilization efficiency. This research sheds new light on the mechanism underlying the ability of PPSB to coordinate nitrogen and carbon metabolism, and provides a feasible way to improve starch production, that is, through engineering PPSB in crops.
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Chen X, He Y, Liu L, Zhu X, Sen B, Wang G. Nitrogen Starvation Enhances the Production of Saturated and Unsaturated Fatty Acids in Aurantiochytrium sp. PKU#SW8 by Regulating Key Biosynthetic Genes. Mar Drugs 2022; 20:621. [PMID: 36286445 DOI: 10.3390/md20100621] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/17/2022] [Accepted: 09/25/2022] [Indexed: 11/05/2022] Open
Abstract
Nitrogen deprivation is known to improve lipid accumulation in microalgae and thraustochytrids. However, the patterns of fatty acid production and the molecular mechanisms underlying the accumulation of unsaturated and saturated fatty acids (SFAs) under nitrogen starvation remain largely unknown for thraustochytrids. In this study, batch culture experiments under nitrogen replete and nitrogen starvation conditions were performed, and the changes in the transcriptome of Aurantiochytrium sp. PKU#SW8 strain between these conditions were investigated. Our results showed improved yields of total fatty acids (TFAs), total unsaturated fatty acids, and total SFAs under nitrogen starvation, which suggested that nitrogen starvation favors the accumulation of both unsaturated and saturated fatty acids in PKU#SW8. However, nitrogen starvation resulted in a more than 2.36-fold increase of SFAs whereas a 1.7-fold increase of unsaturated fatty acids was observed, indicating a disproportionate increase in these groups of fatty acids. The fabD and enoyl-CoA hydratase genes were significantly upregulated under nitrogen starvation, supporting the observed increase in the yield of TFAs from 2.63 ± 0.22 g/L to 3.64 ± 0.16 g/L. Furthermore, the pfaB gene involved in the polyketide synthase (PKS) pathway was significantly upregulated under nitrogen starvation. This suggested that the increased expression of the pfaB gene under nitrogen starvation may be one of the explanations for the increased yield of docosahexaenoic acid by 1.58-fold. Overall, our study advances the current understanding of the molecular mechanisms that underlie the response of thraustochytrids to nitrogen deprivation and their fatty acid biosynthesis.
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Roni MS, Sakil MA, Aktar MM, Takatsuka C, Mukae K, Inoue-Aono Y, Moriyasu Y. Hydrogen Peroxide Mediates Premature Senescence Caused by Darkness and Inorganic Nitrogen Starvation in Physcomitrium patens. Plants (Basel) 2022; 11:2280. [PMID: 36079662 PMCID: PMC9460043 DOI: 10.3390/plants11172280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/22/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
Leaf senescence accompanied by yellowing and Rubisco degradation occurs prematurely in response to various stresses. However, signaling pathways between stress perception and senescence responses are not understood fully, although previous studies suggest the involvement of reactive oxygen species (ROS). While investigating the physiological functions of autophagy in Physcomitrium patens using wild-type (WT) and autophagy-deficient atg5 strains, we found that Physcomitrium colonies senesce prematurely under dark or nitrogen-deficient conditions, with atg5 senescing earlier than WT. In the present study, we measured cellular H2O2, and examined whether H2O2 mediates premature senescence in Physcomitrium colonies. Methyl viologen, an ROS generator, increased cellular H2O2 levels and caused senescence-like symptoms. H2O2 levels were also elevated to the same plateau levels in WT and atg5 under dark or nitrogen-deficient conditions. The ROS scavenger N-acetylcysteine and the ROS source inhibitor carbonyl cyanide m-chlorophenylhydrazone inhibited the increase in H2O2 levels as well as senescence. Upon transfer to a nitrogen-deficient medium, H2O2 levels increased earlier in atg5 than in WT by ~18 h, whereas atg5 yellowed earlier by >2 days. We conclude that the increased H2O2 levels under dark or nitrogen-deficient conditions mediate premature senescence in Physcomitrium but do not explain the different senescence responses of WT and atg5 cells.
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Affiliation(s)
- Md. Shyduzzaman Roni
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
- Department of Horticulture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur 1706, Bangladesh
| | - Md. Arif Sakil
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
- Department of Biochemistry and Molecular Biology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh
| | - Most Mohoshena Aktar
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
- Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Dinajpur 5200, Bangladesh
| | | | - Kyosuke Mukae
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
- Research Institute for Clinical Oncology, Saitama Cancer Center, Saitama 362-0806, Japan
| | - Yuko Inoue-Aono
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Yuji Moriyasu
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
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22
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Iwagami T, Ogawa T, Ishikawa T, Maruta T. Activation of ascorbate metabolism by nitrogen starvation and its physiological impacts in Arabidopsis thaliana. Biosci Biotechnol Biochem 2022; 86:476-489. [PMID: 35090004 DOI: 10.1093/bbb/zbac010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 01/13/2022] [Indexed: 11/12/2022]
Abstract
Redox homeostasis is crucial for plant acclimation to nutrient-deficient conditions, but its molecular mechanisms remain largely unknown. In this study, the effects of nutrient deficiencies on antioxidant systems in Arabidopsis thaliana were investigated. We found that ascorbate content in the plants grown with nitrogen starvation was higher than those with complete nutrition. The higher ascorbate levels were associated with enhanced gene expression of ascorbate biosynthesis enzymes and cytosolic isozymes of the ascorbate-glutathione cycle, suggesting that nitrogen starvation facilitated both consumption and biosynthesis of ascorbate. Nevertheless, we did not identify any phenotypic differences between wild type and ascorbate-deficient mutants (vtc2) under nitrogen starvation. Under high-light stress, the vtc2 mutants suffered severer photoinhibition than wild type. Interestingly, when high-light stress and nitrogen starvation were combined, wild type and vtc2 plants exhibited photoinhibition to the same extent. Based on these findings, we discuss the regulation and role of ascorbate metabolism under nitrogen starvation.
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Affiliation(s)
- Takumi Iwagami
- Graduate School of Natural Science and Technology, Shimane University, Matsue, Shimane, Japan
| | - Takahisa Ogawa
- Graduate School of Natural Science and Technology, Shimane University, Matsue, Shimane, Japan.,Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
| | - Takahiro Ishikawa
- Graduate School of Natural Science and Technology, Shimane University, Matsue, Shimane, Japan.,Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
| | - Takanori Maruta
- Graduate School of Natural Science and Technology, Shimane University, Matsue, Shimane, Japan.,Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
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Liu T, Chen Z, Xiao Y, Yuan M, Zhou C, Liu G, Fang J, Yang B. Biochemical and Morphological Changes Triggered by Nitrogen Stress in the Oleaginous Microalga Chlorella vulgaris. Microorganisms 2022; 10:microorganisms10030566. [PMID: 35336142 PMCID: PMC8949318 DOI: 10.3390/microorganisms10030566] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/20/2022] [Accepted: 02/25/2022] [Indexed: 02/06/2023] Open
Abstract
Oleaginous microalgae have been considered promising sources of biodiesel due to their high lipid content. Nitrogen limitation/starvation is one of the most prominent strategies to induce lipid accumulation in microalgae. Nonetheless, despite numerous studies, the mechanism underlying this approach is not well understood. The aim of this study was to investigate the effect of nitrogen limitation and starvation on biochemical and morphological changes in the microalga Chlorella vulgaris FACHB-1068, thereby obtaining the optimal nitrogen stress strategy for maximizing the lipid productivity of microalgal biomass. The results showed that nitrogen limitation (nitrate concentration < 21.66 mg/L) and starvation enhanced the lipid content but generally decreased the biomass productivity, pigment concentration, and protein content in algal cells. Comparatively, 3-day nitrogen starvation was found to be a more suitable strategy to produce lipid-rich biomass. It resulted in an increased biomass production and satisfactory lipid content of 266 mg/L and 31.33%, respectively. Besides, nitrogen starvation caused significant changes in cell morphology, with an increase in numbers and total size of lipid droplets and starch granules. Under nitrogen starvation, saturated fatty acids (C-16:0, C-20:0, and C-18:0) accounted for the majority of the total fatty acids (~80%), making C. vulgaris FACHB-1068 a potential feedstock for biodiesel production. Our work may contribute to a better understanding of the biochemical and morphological changes in microalgae under nitrogen stress. Besides, our work may provide valuable information on increasing the lipid productivity of oleaginous microalgae by regulating nitrogen supply.
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Affiliation(s)
| | | | | | | | | | | | | | - Bo Yang
- Correspondence: (J.F.); (B.Y.)
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24
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Park SJ, Ahn JW, Choi JI. Improved tolerance of recombinant Chlamydomonas rainhardtii with putative 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase from Pyropia yezoensis to nitrogen starvation. J Microbiol 2021; 60:63-69. [PMID: 34964943 DOI: 10.1007/s12275-022-1491-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 11/29/2022]
Abstract
In a previous study, a putative 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase (ACMSD) was highly expressed in a mutant strain of Pyropia yezoensis, which exhibited an improved growth rate compared to its wild strain. To investigate the functional role of the putative ACMSD (Pyacmsd) of P. yezoensis, the putative Pyacmsd was cloned and expressed in Chlamydomonas reinhardtii. Recombinant C. reinhardtii cells with Pyacmsd (Cr_Pyacmsd) exhibited enhanced tolerance compared to control C. reinhardtii cells (Cr_control) under nitrogen starvation. Notably, Cr_Pyacmsd cells showed accumulation of lipids in nitrogen-enriched conditions. These results demonstrate the role of Pyacmsd in the generation of acetyl-coenzyme A. Thus, it can be used to enhance the production of biofuel using microalgae such as C. reinhardtii and increase the tolerance of other biological systems to nitrogen-deficient conditions.
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Affiliation(s)
- Seo-Jeong Park
- Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Joon Woo Ahn
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, 56212, Republic of Korea
| | - Jong-Il Choi
- Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju, 61186, Republic of Korea.
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25
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Nasaruddin ML, Tajul Arifin K. Application of Metabolomics in the Study of Starvation-Induced Autophagy in Saccharomyces cerevisiae: A Scoping Review. J Fungi (Basel) 2021; 7:987. [PMID: 34829274 DOI: 10.3390/jof7110987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 11/18/2022] Open
Abstract
This scoping review is aimed at the application of the metabolomics platform to dissect key metabolites and their intermediates to observe the regulatory mechanisms of starvation-induced autophagy in Saccharomyces cerevisiae. Four research papers were shortlisted in this review following the inclusion and exclusion criteria. We observed a commonly shared pathway undertaken by S. cerevisiae under nutritional stress. Targeted and untargeted metabolomics was applied in either of these studies using varying platforms resulting in the annotation of several different observable metabolites. We saw a commonly shared pathway undertaken by S. cerevisiae under nutritional stress. Following nitrogen starvation, the concentration of cellular nucleosides was altered as a result of autophagic RNA degradation. Additionally, it is also found that autophagy replenishes amino acid pools to sustain macromolecule synthesis. Furthermore, in glucose starvation, nucleosides were broken down into carbonaceous metabolites that are being funneled into the non-oxidative pentose phosphate pathway. The ribose salvage allows for the survival of starved yeast. Moreover, acute glucose starvation showed autophagy to be involved in maintaining ATP/energy levels. We highlighted the practicality of metabolomics as a tool to better understand the underlying mechanisms involved to maintain homeostasis by recycling degradative products to ensure the survival of S. cerevisiae under starvation. The application of metabolomics has extended the scope of autophagy and provided newer intervention targets against cancer as well as neurodegenerative diseases in which autophagy is implicated.
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Toyoda Y, Saitoh S. Fission Yeast TORC2 Signaling Pathway Ensures Cell Proliferation under Glucose-Limited, Nitrogen-Replete Conditions. Biomolecules 2021; 11:1465. [PMID: 34680098 DOI: 10.3390/biom11101465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/29/2021] [Accepted: 10/02/2021] [Indexed: 12/25/2022] Open
Abstract
Target of rapamycin (TOR) kinases form two distinct complexes, TORC1 and TORC2, which are evolutionarily conserved among eukaryotes. These complexes control intracellular biochemical processes in response to changes in extracellular nutrient conditions. Previous studies using the fission yeast, Schizosaccharomyces pombe, showed that the TORC2 signaling pathway, which is essential for cell proliferation under glucose-limited conditions, ensures cell-surface localization of a high-affinity hexose transporter, Ght5, by downregulating its endocytosis. The TORC2 signaling pathway retains Ght5 on the cell surface, depending on the presence of nitrogen sources in medium. Ght5 is transported to vacuoles upon nitrogen starvation. In this review, we discuss the molecular mechanisms underlying this regulation to cope with nutritional stress, a response which may be conserved from yeasts to mammals.
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Li X, Liang Y, Li K, Jin P, Tang J, Klepacz-Smółka A, Ledakowicz S, Daroch M. Effects of Low Temperature, Nitrogen Starvation and Their Combination on the Photosynthesis and Metabolites of Thermosynechococcus E542: A Comparison Study. Plants (Basel) 2021; 10:plants10102101. [PMID: 34685910 PMCID: PMC8537721 DOI: 10.3390/plants10102101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 11/25/2022]
Abstract
Both low temperature and nitrogen starvation caused chlorosis of cyanobacteria. Here, in this study, for the first time, we compared the effects of low temperature, nitrogen starvation, and their combination on the photosynthesis and metabolites of a thermophilic cyanobacterium strain, Thermosynechococcus E542. Under various culture conditions, the growth rates, pigment contents, and chlorophyll fluorescence were monitored, and the composition of alkanes, lipidomes, and carbohydrates were determined. It was found that low temperature (35 °C) significantly suppressed the growth of Thermosynechococcus E542. Nitrogen starvation at 45 °C and 55 °C did not affect the growth; however, combined treatment of low temperature and nitrogen starvation led to the lowest growth rate and biomass productivity. Both low temperature and nitrogen starvation caused significantly declined contents of pigments, but they resulted in a different effect on the OJIP curves, and their combination led to the lowest pigment contents. The composition of fatty acids and alkanes was altered upon low-temperature cultivation, while nitrogen starvation caused reduced contents of all lipids. The low temperature did not affect carbohydrate contents, while nitrogen starvation greatly enhanced carbohydrate content, and their combination did not enhance carbohydrate content, but led to reduced productivity. These results revealed the influence of low temperature, nitrogen starvation, and their combined treatment for the accumulation of phycobiliproteins, lipids, and carbohydrates of a thermophilic cyanobacterium strain, Thermosynechococcus E542.
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Affiliation(s)
- Xingkang Li
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
- Department School of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China
| | - Yuanmei Liang
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
| | - Kai Li
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
| | - Peng Jin
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
| | - Jie Tang
- School of Food and Bioengineering, Chengdu University, Chengdu 610106, China;
| | - Anna Klepacz-Smółka
- Department of Bioprocess Engineering, Faculty of Process and Environmental Engineering, Lodz University of Technology, ul. Wolczanska 213, 90-924 Lodz, Poland; (A.K.-S.); (S.L.)
| | - Stanislaw Ledakowicz
- Department of Bioprocess Engineering, Faculty of Process and Environmental Engineering, Lodz University of Technology, ul. Wolczanska 213, 90-924 Lodz, Poland; (A.K.-S.); (S.L.)
| | - Maurycy Daroch
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
- Correspondence: ; Tel.: +86-0755-26032184
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28
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Huo L, Guo Z, Wang Q, Cheng L, Jia X, Wang P, Gong X, Li C, Ma F. Enhanced Autophagic Activity Improved the Root Growth and Nitrogen Utilization Ability of Apple Plants under Nitrogen Starvation. Int J Mol Sci 2021; 22:ijms22158085. [PMID: 34360850 PMCID: PMC8348665 DOI: 10.3390/ijms22158085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 07/15/2021] [Accepted: 07/20/2021] [Indexed: 12/26/2022] Open
Abstract
Autophagy is a conserved degradation pathway for recycling damaged organelles and aberrant proteins, and its important roles in plant adaptation to nutrient starvation have been generally reported. Previous studies found that overexpression of autophagy-related (ATG) gene MdATG10 enhanced the autophagic activity in apple roots and promoted their salt tolerance. The MdATG10 expression was induced by nitrogen depletion condition in both leaves and roots of apple plants. This study aimed to investigate the differences in the growth and physiological status between wild type and MdATG10-overexpressing apple plants in response to nitrogen starvation. A hydroponic system containing different nitrogen levels was used. The study found that the reduction in growth and nitrogen concentrations in different tissues caused by nitrogen starvation was relieved by MdATG10 overexpression. Further studies demonstrated the increased root growth and the higher nitrogen absorption and assimilation ability of transgenic plants. These characteristics contributed to the increased uptake of limited nitrogen nutrients by transgenic plants, which also reduced the starvation damage to the chloroplasts. Therefore, the MdATG10-overexpressing apple plants could maintain higher photosynthetic ability and possess better growth under nitrogen starvation stress.
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Affiliation(s)
- Liuqing Huo
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Shaanxi 712100, China; (L.H.); (Z.G.); (Q.W.); (L.C.); (X.J.); (P.W.); (X.G.)
- Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas, College of Horticulture Science, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China
| | - Zijian Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Shaanxi 712100, China; (L.H.); (Z.G.); (Q.W.); (L.C.); (X.J.); (P.W.); (X.G.)
| | - Qi Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Shaanxi 712100, China; (L.H.); (Z.G.); (Q.W.); (L.C.); (X.J.); (P.W.); (X.G.)
| | - Li Cheng
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Shaanxi 712100, China; (L.H.); (Z.G.); (Q.W.); (L.C.); (X.J.); (P.W.); (X.G.)
| | - Xin Jia
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Shaanxi 712100, China; (L.H.); (Z.G.); (Q.W.); (L.C.); (X.J.); (P.W.); (X.G.)
| | - Ping Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Shaanxi 712100, China; (L.H.); (Z.G.); (Q.W.); (L.C.); (X.J.); (P.W.); (X.G.)
| | - Xiaoqing Gong
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Shaanxi 712100, China; (L.H.); (Z.G.); (Q.W.); (L.C.); (X.J.); (P.W.); (X.G.)
| | - Cuiying Li
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Shaanxi 712100, China; (L.H.); (Z.G.); (Q.W.); (L.C.); (X.J.); (P.W.); (X.G.)
- Correspondence: (C.L.); (F.M.)
| | - Fengwang Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Shaanxi 712100, China; (L.H.); (Z.G.); (Q.W.); (L.C.); (X.J.); (P.W.); (X.G.)
- Correspondence: (C.L.); (F.M.)
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29
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Orthwein T, Scholl J, Spät P, Lucius S, Koch M, Macek B, Hagemann M, Forchhammer K. The novel P II-interactor PirC identifies phosphoglycerate mutase as key control point of carbon storage metabolism in cyanobacteria. Proc Natl Acad Sci U S A 2021; 118:e2019988118. [PMID: 33526690 DOI: 10.1073/pnas.2019988118] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Nitrogen limitation imposes a major transition in the lifestyle of nondiazotrophic cyanobacteria that is controlled by a complex interplay of regulatory factors involving the pervasive signal processor PII Immediately upon nitrogen limitation, newly fixed carbon is redirected toward glycogen synthesis. How the metabolic switch for diverting fixed carbon toward the synthesis of glycogen or of cellular building blocks is operated was so far poorly understood. Here, using the nondiazotrophic cyanobacterium Synechocystis sp. PCC 6803 as model system, we identified a novel PII interactor, the product of the sll0944 gene, which we named PirC. We show that PirC binds to and inhibits the activity of 2,3-phosphoglycerate-independent phosphoglycerate mutase (PGAM), the enzyme that deviates newly fixed CO2 toward lower glycolysis. The binding of PirC to either PII or PGAM is tuned by the metabolite 2-oxoglutarate (2-OG), which accumulates upon nitrogen starvation. In these conditions, the high levels of 2-OG dissociate the PirC-PII complex to promote PirC binding to and inhibition of PGAM. Accordingly, a PirC-deficient mutant showed strongly reduced glycogen levels upon nitrogen deprivation, whereas polyhydroxybutyrate granules were overaccumulated compared to wild-type. Metabolome analysis revealed an imbalance in 3-phosphoglycerate to pyruvate levels in the pirC mutant, confirming that PirC controls the carbon flux in cyanobacteria via mutually exclusive interaction with either PII or PGAM.
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Krauspe V, Fahrner M, Spät P, Steglich C, Frankenberg-Dinkel N, Maček B, Schilling O, Hess WR. Discovery of a small protein factor involved in the coordinated degradation of phycobilisomes in cyanobacteria. Proc Natl Acad Sci U S A 2021; 118:e2012277118. [PMID: 33509926 DOI: 10.1073/pnas.2012277118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
During genome analysis, genes encoding small proteins are frequently neglected. Accordingly, small proteins have remained underinvestigated in all domains of life. Based on a previous systematic search for such genes, we present the functional analysis of the 66 amino acids protein NblD in a photosynthetic cyanobacterium. We show that NblD plays a crucial role during the coordinated dismantling of phycobilisome light-harvesting complexes. This disassembly is triggered when the cells become starved for nitrogen, a condition that frequently occurs in nature. Similar to NblA that tags phycobiliproteins for proteolysis, NblD binds to phycocyanin polypeptides but has a different function. The results show that, even in a well-investigated process, crucial new players can be discovered if small proteins are taken into consideration. Phycobilisomes are the major pigment–protein antenna complexes that perform photosynthetic light harvesting in cyanobacteria, rhodophyte, and glaucophyte algae. Up to 50% of the cellular nitrogen can be stored in their giant structures. Accordingly, upon nitrogen depletion, phycobilisomes are rapidly degraded following an intricate genetic program. Here, we describe the role of NblD, a cysteine-rich, small protein in this process in cyanobacteria. Deletion of the nblD gene in the cyanobacterium Synechocystis sp. PCC 6803 prevented the degradation of phycobilisomes, leading to a nonbleaching (nbl) phenotype, which could be complemented by a plasmid-localized gene copy. Competitive growth experiments between the ΔnblD and the wild-type strain provided direct evidence for the physiological importance of NblD under nitrogen-limited conditions. Ectopic expression of NblD under nitrogen-replete conditions showed no effect, in contrast to the unrelated proteolysis adaptors NblA1 and NblA2, which can trigger phycobilisome degradation. Transcriptome analysis indicated increased nblA1/2 transcript levels in the ΔnblD strain during nitrogen starvation, implying that NblD does not act as a transcriptional (co)regulator. However, immunoprecipitation and far-western experiments identified the chromophorylated (holo form) of the phycocyanin β-subunit (CpcB) as its target, while apo-CpcB was not bound. The addition of recombinant NblD to isolated phycobilisomes caused a reduction in phycocyanin absorbance and a broadening and shifting of the peak to lower wavelengths, indicating the occurrence of structural changes. These data demonstrate that NblD plays a crucial role in the coordinated dismantling of phycobilisomes and add it as a factor to the genetically programmed response to nitrogen starvation.
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Ludewig U, Vatov E, Hedderich D, Neuhäuser B. Adjusting plant nutrient acquisition to fluctuating availability: transcriptional co-regulation of the nitrate and phosphate deprivation responses in roots. J Exp Bot 2021; 72:3500-3503. [PMID: 33948653 PMCID: PMC8096598 DOI: 10.1093/jxb/erab131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This article comments on: Safi A, Medici A, Szponarski W, Martin F, Clement-Vidal A, Marshall-Colon A, Ruffel S, Gaymard F, Rouached H, Leclercq J, Coruzzi G, Lacombe B, Krouk G. 2021. GARP transcription factors repress Arabidopsis nitrogen starvation response via ROS-dependent and -independent pathways. Journal of Experimental Botany 72, 3881–3901.
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Affiliation(s)
- Uwe Ludewig
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Fruwirthstr., Stuttgart, Germany
| | - Emil Vatov
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Fruwirthstr., Stuttgart, Germany
| | - Dominik Hedderich
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Fruwirthstr., Stuttgart, Germany
| | - Benjamin Neuhäuser
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Fruwirthstr., Stuttgart, Germany
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Koksharova OA, Butenko IO, Pobeguts OV, Safronova NA, Govorun VM. β-N-Methylamino-L-Alanine (BMAA) Causes Severe Stress in Nostoc sp. PCC 7120 Cells under Diazotrophic Conditions: A Proteomic Study. Toxins (Basel) 2021; 13:325. [PMID: 33946501 PMCID: PMC8147232 DOI: 10.3390/toxins13050325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 04/07/2021] [Accepted: 04/28/2021] [Indexed: 12/24/2022] Open
Abstract
Non-proteinogenic neurotoxic amino acid β-N-methylamino-L-alanine (BMAA) is synthesized by cyanobacteria, diatoms, and dinoflagellates, and is known to be a causative agent of human neurodegenerative diseases. Different phytoplankton organisms' ability to synthesize BMAA could indicate the importance of this molecule in the interactions between microalgae in nature. We were interested in the following: what kinds of mechanisms underline BMAA's action on cyanobacterial cells in different nitrogen supply conditions. Herein, we present a proteomic analysis of filamentous cyanobacteria Nostoc sp. PCC 7120 cells that underwent BMAA treatment in diazotrophic conditions. In diazotrophic growth conditions, to survive, cyanobacteria can use only biological nitrogen fixation to obtain nitrogen for life. Note that nitrogen fixation is an energy-consuming process. In total, 1567 different proteins of Nostoc sp. PCC 7120 were identified by using LC-MS/MS spectrometry. Among them, 123 proteins belonging to different functional categories were selected-due to their notable expression differences-for further functional analysis and discussion. The presented proteomic data evidences that BMAA treatment leads to very strong (up to 80%) downregulation of α (NifD) and β (NifK) subunits of molybdenum-iron protein, which is known to be a part of nitrogenase. This enzyme is responsible for catalyzing nitrogen fixation. The genes nifD and nifK are under transcriptional control of a global nitrogen regulator NtcA. In this study, we have found that BMAA impacts in a total of 22 proteins that are under the control of NtcA. Moreover, BMAA downregulates 18 proteins that belong to photosystems I or II and light-harvesting complexes; BMAA treatment under diazotrophic conditions also downregulates five subunits of ATP synthase and enzyme NAD(P)H-quinone oxidoreductase. Therefore, we can conclude that the disbalance in energy and metabolite amounts leads to severe intracellular stress that induces the upregulation of stress-activated proteins, such as starvation-inducible DNA-binding protein, four SOS-response enzymes, and DNA repair enzymes, nine stress-response enzymes, and four proteases. The presented data provide new leads into the ecological impact of BMAA on microalgal communities that can be used in future investigations.
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Affiliation(s)
- Olga A. Koksharova
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Leninskie Gory, 1-40, 119991 Moscow, Russia;
- Institute of Molecular Genetics of National Research Center “Kurchatov Institute”, Kurchatov Square, 2, 123182 Moscow, Russia
| | - Ivan O. Butenko
- Scientific-Research Institute of Physical-Chemical Medicine, 119435 Moscow, Russia; (I.O.B.); (O.V.P.); (V.M.G.)
| | - Olga V. Pobeguts
- Scientific-Research Institute of Physical-Chemical Medicine, 119435 Moscow, Russia; (I.O.B.); (O.V.P.); (V.M.G.)
| | - Nina A. Safronova
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Leninskie Gory, 1-40, 119991 Moscow, Russia;
| | - Vadim M. Govorun
- Scientific-Research Institute of Physical-Chemical Medicine, 119435 Moscow, Russia; (I.O.B.); (O.V.P.); (V.M.G.)
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Liu H, Able AJ, Able JA. Nitrogen Starvation-Responsive MicroRNAs Are Affected by Transgenerational Stress in Durum Wheat Seedlings. Plants (Basel) 2021; 10:826. [PMID: 33919185 DOI: 10.3390/plants10050826] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/16/2021] [Accepted: 04/19/2021] [Indexed: 11/17/2022]
Abstract
Stress events have transgenerational effects on plant growth and development. In Mediterranean regions, water-deficit and heat (WH) stress is a frequent issue that negatively affects crop yield and quality. Nitrogen (N) is an essential plant macronutrient and often a yield-limiting factor for crops. Here, the response of durum wheat seedlings to N starvation under the transgenerational effects of WH stress was investigated in two genotypes. Both genotypes showed a significant reduction in seedling height, leaf number, shoot and root weight (fresh and dry), primary root length, and chlorophyll content under N starvation stress. However, in the WH stress-tolerant genotype, the percentage reduction of most traits was lower in progeny from the stressed parents than progeny from the control parents. Small RNA sequencing identified 1534 microRNAs in different treatment groups. Differentially expressed microRNAs (DEMs) were characterized subject to N starvation, parental stress and genotype factors, with their target genes identified in silico. GO and KEGG enrichment analyses revealed the biological functions, associated with DEM-target modules in stress adaptation processes, that could contribute to the phenotypic differences observed between the two genotypes. The study provides the first evidence of the transgenerational effects of WH stress on the N starvation response in durum wheat.
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Ogata T, Kuroki K. Regulation of mating and mating-type-specific genes in Zygosaccharomyces sp. yeast. Yeast 2021; 38:471-479. [PMID: 33811363 DOI: 10.1002/yea.3561] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/16/2021] [Accepted: 03/26/2021] [Indexed: 11/11/2022] Open
Abstract
Zygosaccharomyces sp. is an industrially important yeast for the production traditional fermented foods in Japan. At present, however, there is no easy method for mating Zygosaccharomyces sp. strains in the laboratory; furthermore, little is known about the expression of mating-type-specific genes in this yeast. Here, mating was observed when Zygosaccharomyces sp. was subjected to nitrogen-starvation conditions. The expression of mating-type-specific genes, Zygo STE6 and Zygo MFα1, was induced under nitrogen-starvation conditions, as confirmed by lacZ reporter assay. This expression was mating-type-specific: Zygo STE6 was expressed specifically for mating-type a, whereas and Zygo MFα1 was expressed specifically for mating-type α. Yeast strains Zygosaccharomyces rouxii DL2 and DA2, derived from type strain Z. rouxii CBS732, did not show mating even under nitrogen-starvation conditions. Gene sequencing revealed that the Zygo STE12 in Z. rouxii CBS732 has a frameshift mutation. Under nitrogen starvation, mating was observed in both DL2 and DA2 transformed with the wild-type Zygo STE12. The expression of Zygo STE6 in Z. rouxii DL2 transformed with wild-type Zygo STE12 under nitrogen-starvation conditions was confirmed by lacZ reporter assay. Collectively, these results revealed that, under nitrogen-starvation conditions, Zygosaccharomyces sp. can mate and mating-type-specific genes are expressed. Furthermore, Zygo Ste12 is essential for both mating and the expression of mating-type-specific genes in Zygosaccharomyces sp.
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Affiliation(s)
- Tomoo Ogata
- Department of Biotechnology, Maebashi Institute of Technology, Maebashi, Japan
| | - Katsuaki Kuroki
- Department of Biotechnology, Maebashi Institute of Technology, Maebashi, Japan
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Grau FC, Burkovski A, Muller YA. Crystal structures of adenylylated and unadenylylated P II protein GlnK from Corynebacterium glutamicum. Acta Crystallogr D Struct Biol 2021; 77:325-335. [PMID: 33645536 PMCID: PMC7919409 DOI: 10.1107/s2059798321000735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/21/2021] [Indexed: 11/10/2022] Open
Abstract
PII proteins are ubiquitous signaling proteins that are involved in the regulation of the nitrogen/carbon balance in bacteria, archaea, and some plants and algae. Signal transduction via PII proteins is modulated by effector molecules and post-translational modifications in the PII T-loop. Whereas the binding of ADP, ATP and the concomitant binding of ATP and 2-oxoglutarate (2OG) engender two distinct conformations of the T-loop that either favor or disfavor the interaction with partner proteins, the structural consequences of post-translational modifications such as phosphorylation, uridylylation and adenylylation are far less well understood. In the present study, crystal structures of the PII protein GlnK from Corynebacterium glutamicum have been determined, namely of adenylylated GlnK (adGlnK) and unmodified unadenylylated GlnK (unGlnK). AdGlnK has been proposed to act as an inducer of the transcription repressor AmtR, and the adenylylation of Tyr51 in GlnK has been proposed to be a prerequisite for this function. The structures of unGlnK and adGlnK allow the first atomic insights into the structural implications of the covalent attachment of an AMP moiety to the T-loop. The overall GlnK fold remains unaltered upon adenylylation, and T-loop adenylylation does not appear to interfere with the formation of the two major functionally important T-loop conformations, namely the extended T-loop in the canonical ADP-bound state and the compacted T-loop that is adopted upon the simultaneous binding of Mg-ATP and 2OG. Thus, the PII-typical conformational switching mechanism appears to be preserved in GlnK from C. glutamicum, while at the same time the functional repertoire becomes expanded through the accommodation of a peculiar post-translational modification.
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Affiliation(s)
- Florian C. Grau
- Division of Biotechnology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 91, 91052 Erlangen, Germany
| | - Andreas Burkovski
- Division of Microbiology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, 91058 Erlangen, Germany
| | - Yves A. Muller
- Division of Biotechnology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 91, 91052 Erlangen, Germany
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Doello S, Burkhardt M, Forchhammer K. The essential role of sodium bioenergetics and ATP homeostasis in the developmental transitions of a cyanobacterium. Curr Biol 2021; 31:1606-1615.e2. [PMID: 33571435 DOI: 10.1016/j.cub.2021.01.065] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/30/2020] [Accepted: 01/19/2021] [Indexed: 10/22/2022]
Abstract
The ability to resume growth after a dormant period is an important strategy for the survival and spreading of bacterial populations. Energy homeostasis is critical in the transition into and out of a quiescent state. Synechocystis sp. PCC 6803, a non-diazotrophic cyanobacterium, enters metabolic dormancy as a response to nitrogen starvation. We used Synechocystis as a model to investigate the regulation of ATP homeostasis during dormancy, and we unraveled a critical role for sodium bioenergetics in dormant cells. During nitrogen starvation, cells reduce their ATP levels and engage sodium bioenergetics to maintain the minimum ATP content required for viability. When nitrogen becomes available, energy requirements rise, and cells immediately increase ATP levels, employing sodium bioenergetics and glycogen catabolism. These processes allow them to restore the photosynthetic machinery and resume photoautotrophic growth. Our work reveals a precise regulation of the energy metabolism essential for bacterial survival during periods of nutrient deprivation.
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Affiliation(s)
- Sofia Doello
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - Markus Burkhardt
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - Karl Forchhammer
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany.
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Doppler P, Kornpointner C, Halbwirth H, Remias D, Spadiut O. Tetraedron minimum, First Reported Member of Hydrodictyaceae to Accumulate Secondary Carotenoids. Life (Basel) 2021; 11:107. [PMID: 33573287 PMCID: PMC7911234 DOI: 10.3390/life11020107] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/17/2021] [Accepted: 01/27/2021] [Indexed: 01/23/2023] Open
Abstract
We isolated a novel strain of the microalga Tetraedron minimum in Iceland from a terrestrial habitat. During long-term cultivation, a dish culture turned orange, indicating the presence of secondary pigments. Thus, we characterized T. minimum for growth and possible carotenoid production in different inorganic media. In a lab-scale photobioreactor, we confirmed that nitrogen starvation in combination with salt stress triggered a secondary carotenoid accumulation. The development of the pigment composition and the antioxidant capacity of the extracts was analyzed throughout the cultivations. The final secondary carotenoid composition was, on average, 61.1% astaxanthin and 38.9% adonixanthin. Moreover, the cells accumulated approx. 83.1% unsaturated fatty acids. This work presents the first report of the formation of secondary carotenoids within the family Hydrodictyaceae (Sphaeropleales, Chlorophyta).
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Affiliation(s)
- Philipp Doppler
- Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria;
| | - Christoph Kornpointner
- Research Division Phytochemistry and Plant Biochemistry, Institute of Chemical, Environmental, and Bioscience Engineering, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria; (C.K.); (H.H.)
| | - Heidi Halbwirth
- Research Division Phytochemistry and Plant Biochemistry, Institute of Chemical, Environmental, and Bioscience Engineering, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria; (C.K.); (H.H.)
| | - Daniel Remias
- School of Engineering, University of Applied Sciences Upper Austria, Stelzhamerstr. 23, 4600 Wels, Austria
| | - Oliver Spadiut
- Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria;
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Li YL, Liu JL. Hypoosmolality impedes cytoophidium integrity during nitrogen starvation. Yeast 2021; 38:276-289. [PMID: 33294993 DOI: 10.1002/yea.3542] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/18/2020] [Accepted: 12/03/2020] [Indexed: 12/26/2022] Open
Abstract
CTP synthase (CTPS) cytoophidia have been found in many species over domains of life in the past 10 years, implying the evolutionary conservation of these structures. However, there are differences in cytoophidia between species. The difference in CTPS cytoophidium properties between budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) inspires this research. We study the effects of culture environment on cytoophidia in S. cerevisiae by switching to the optimal medium for S. pombe. S. cerevisiae CTPS cytoophidium fragmentation and pseudohyphae formation are observed after treatment with S. pombe medium YES instead of S. cerevisiae medium YPD. By modifying the level of each ingredient of the media, we find that hypoosmolality impedes cytoophidium integrity during nitrogen starvation. Our study demonstrates the relationship between cytoophidium integrity and environmental stress, supporting the role of cytoophidia in stress resistance.
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Affiliation(s)
- Yi-Lan Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
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Kong L, Zhang Y, Du W, Xia H, Fan S, Zhang B. Signaling Responses to N Starvation: Focusing on Wheat and Filling the Putative Gaps With Findings Obtained in Other Plants. A Review. Front Plant Sci 2021; 12:656696. [PMID: 34135921 PMCID: PMC8200679 DOI: 10.3389/fpls.2021.656696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/08/2021] [Indexed: 05/16/2023]
Abstract
Wheat is one of the most important food crops worldwide. In recent decades, fertilizers, especially nitrogen (N), have been increasingly utilized to maximize wheat productivity. However, a large proportion of N is not used by plants and is in fact lost into the environment and causes serious environmental pollution. Therefore, achieving a low N optimum via efficient physiological and biochemical processes in wheat grown under low-N conditions is highly important for agricultural sustainability. Although N stress-related N capture in wheat has become a heavily researched subject, how this plant adapts and responds to N starvation has not been fully elucidated. This review summarizes the current knowledge on the signaling mechanisms activated in wheat plants in response to N starvation. Furthermore, we filled the putative gaps on this subject with findings obtained in other plants, primarily rice, maize, and Arabidopsis. Phytohormones have been determined to play essential roles in sensing environmental N starvation and transducing this signal into an adjustment of N transporters and phenotypic adaptation. The critical roles played by protein kinases and critical kinases and phosphatases, such as MAPK and PP2C, as well as the multifaceted functions of transcription factors, such as NF-Y, MYB, DOF, and WRKY, in regulating the expression levels of their target genes (proteins) for low-N tolerance are also discussed. Optimization of root system architecture (RSA) via root branching and thinning, improvement of N acquisition and assimilation, and fine-tuned autophagy are pivotal strategies by which plants respond to N starvation. In light of these findings, we attempted to construct regulatory networks for RSA modification and N uptake, transport, assimilation, and remobilization.
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Affiliation(s)
- Lingan Kong
- Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- College of Life Science, Shandong Normal University, Jinan, China
| | - Yunxiu Zhang
- Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Wanying Du
- Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- College of Life Science, Shandong Normal University, Jinan, China
| | - Haiyong Xia
- Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Shoujin Fan
- College of Life Science, Shandong Normal University, Jinan, China
| | - Bin Zhang
- Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- *Correspondence: Bin Zhang,
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Krauspe V, Timm S, Hagemann M, Hess WR. Phycobilisome breakdown effector NblD is required to maintain the cellular amino acid composition during nitrogen starvation. J Bacteriol 2021; 204:JB0015821. [PMID: 34228497 DOI: 10.1128/JB.00158-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Small proteins are critically involved in the acclimation response of photosynthetic cyanobacteria to nitrogen starvation. NblD is the 66-amino-acid effector of nitrogen-limitation-induced phycobilisome breakdown, which is believed to replenish the cellular amino acid pools. To address the physiological functions of NblD, the concentrations of amino acids, intermediates of the arginine catabolism pathway and several organic acids were measured during the response to nitrogen starvation in the cyanobacterium Synechocystis sp. PCC 6803 wild type and in an nblD deletion strain. A characteristic signature of metabolite pool composition was identified, which shows that NblD-mediated phycobilisome degradation is required to maintain the cellular amino acid and organic acid pools during nitrogen starvation. Specific deviations from the wild type suggest wider-reaching effects that also affect such processes as redox homeostasis via glutathione and tetrapyrrole biosynthesis, both of which are linked to the strongly decreased glutamate pool, and transcriptional reprogramming via an enhanced concentration of 2-oxoglutarate, the metabolite co-regulator of the NtcA transcription factor. The essential role played by NblD in metabolic homeostasis is consistent with the widespread occurrence of NblD throughout the cyanobacterial radiation and the previously observed strong positive selection for the nblD gene under fluctuating nitrogen supply. Importance Cyanobacteria play important roles in the global carbon and nitrogen cycles. In their natural environment, these organisms are exposed to fluctuating nutrient conditions. Nitrogen starvation induces a coordinated nitrogen-saving program that includes the breakdown of nitrogen-rich photosynthetic pigments, particularly phycobiliproteins. The small protein NblD was recently identified as an effector of phycobilisome breakdown in cyanobacteria. In this study, we demonstrate that the NblD-mediated degradation of phycobiliproteins is needed to sustain cellular pools of soluble amino acids and other crucial metabolites. The essential role played by NblD in metabolic homeostasis explains why genes encoding this small protein are conserved in almost all members of cyanobacterial radiation.
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Leyland B, Zarka A, Didi-Cohen S, Boussiba S, Khozin-Goldberg I. High Resolution Proteome of Lipid Droplets Isolated from the Pennate Diatom Phaeodactylum tricornutum (Bacillariophyceae) Strain pt4 provides mechanistic insights into complex intracellular coordination during nitrogen deprivation. J Phycol 2020; 56:1642-1663. [PMID: 32779202 DOI: 10.1111/jpy.13063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/14/2020] [Accepted: 07/12/2020] [Indexed: 05/08/2023]
Abstract
Lipid droplets (LDs) are an organelle conserved amongst all eukaryotes, consisting of a neutral lipid core surrounded by a polar lipid monolayer. Many species of microalgae accumulate LDs in response to stress conditions, such as nitrogen starvation. Here, we report the isolation and proteomic profiling of LD proteins from the model oleaginous pennate diatom Phaeodactylum tricornutum, strain Pt4 (UTEX 646). We also provide a quantitative description of LD morphological ontogeny, and fatty acid content. Novel cell disruption and LD isolation methods, combined with suspension-trapping and nanoflow liquid chromatography coupled to high resolution mass spectrometry, yielded an unprecedented number of LD proteins. Predictive annotation of the LD proteome suggests a broad assemblage of proteins with diverse functions, including lipid metabolism and vesicle trafficking, as well as ribosomal and proteasomal machinery. These proteins provide mechanistic insights into LD processes, and evidence for interactions between LDs and other organelles. We identify for the first time several key steps in diatom LD-associated triacylglycerol biosynthesis. Bioinformatic analyses of the LD proteome suggests multiple protein targeting mechanisms, including amphipathic helices, post-translational modifications, and translocation machinery. This work corroborates recent findings from other strains of P. tricornutum, other diatoms, and other eukaryotic organisms, suggesting that the fundamental proteins orchestrating LDs are conserved, and represent an ancient component of the eukaryotic endomembrane system. We postulate a comprehensive model of nitrogen starvation-induced diatom LDs on a molecular scale, and provide a wealth of candidates for metabolic engineering, with the potential to eventually customize LD contents.
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Affiliation(s)
- Ben Leyland
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Aliza Zarka
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Shoshana Didi-Cohen
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Sammy Boussiba
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Inna Khozin-Goldberg
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
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Abstract
Nitrate transporter 2.5 (NRT2.5) was originally characterized as the transporter for nitrogen (N) limitation. In Arabidopsis, NRT2.5 is expressed mainly under extremely low NO3- and N starvation conditions, and this must work in conjunction with NAR2.1. NRT2.5 is expressed both in the roots and leaves in Arabidopsis, poplars, tea trees and cassava. This is also expressed in the seeds of Arabidopsis and wheat. In wheat, NRT2.5 is expressed in the embryo and shell and plays a role in the accumulation of NO3- in the seeds. In maize, this is also expressed in silk, cobs and tassel husk leaves. In rice, OsNRT2.5 (also known as OsNRT2.3a) may help the species to remove NO3- from the roots to shoots. In addition, NRT2.5 may interact with TGA3, MYC1, LBD37, LBD38, TaNAC2 and other transcription factors and participate in the transmission of NO3- signals. The present review summarizes the functions of NRT2.5 in different plant species, which may help plant breeders and molecular biologists to improve crop yield. Abbreviations: NRT, Nitrate transporter; NUE, nitrogen use efficiency; PTR, peptide transporter; NPF, nitrate peptide transporter family; CLC, chloride channel; LAC1/SLAH, slow anion channel-associated 1 homolog 3; LATS, low-affinity transporter systems; HATS, high-affinity transport systems; NNP, nitrate-nitrite-porter; MFS, major facilitator superfamily.
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Affiliation(s)
- Ranran Liu
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan, P.R. China
| | - Ting Jia
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan, P.R. China
| | - Bing Cui
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan, P.R. China
| | - Jie Song
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan, P.R. China
- CONTACT Jie Song Jinan250014, P.R. China
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McQuail J, Switzer A, Burchell L, Wigneshweraraj S. The RNA-binding protein Hfq assembles into foci-like structures in nitrogen starved Escherichia coli. J Biol Chem 2020; 295:12355-12367. [PMID: 32532816 PMCID: PMC7458820 DOI: 10.1074/jbc.ra120.014107] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/09/2020] [Indexed: 11/13/2022] Open
Abstract
The initial adaptive responses to nutrient depletion in bacteria often occur at the level of gene expression. Hfq is an RNA-binding protein present in diverse bacterial lineages that contributes to many different aspects of RNA metabolism during gene expression. Using photoactivated localization microscopy and single-molecule tracking, we demonstrate that Hfq forms a distinct and reversible focus-like structure in Escherichia coli specifically experiencing long-term nitrogen starvation. Using the ability of T7 phage to replicate in nitrogen-starved bacteria as a biological probe of E. coli cell function during nitrogen starvation, we demonstrate that Hfq foci have a role in the adaptive response of E. coli to long-term nitrogen starvation. We further show that Hfq foci formation does not depend on gene expression once nitrogen starvation has set in and occurs indepen-dently of the transcription factor N-regulatory protein C, which activates the initial adaptive response to N starvation in E. coli These results serve as a paradigm to demonstrate that bacterial adaptation to long-term nutrient starvation can be spatiotemporally coordinated and can occur independently of de novo gene expression during starvation.
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Affiliation(s)
- Josh McQuail
- Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Amy Switzer
- Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Lynn Burchell
- Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Sivaramesh Wigneshweraraj
- Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
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Kobayashi K, Osawa Y, Yoshihara A, Shimojima M, Awai K. Relationship Between Glycerolipids and Photosynthetic Components During Recovery of Thylakoid Membranes From Nitrogen Starvation-Induced Attenuation in Synechocystis sp. PCC 6803. Front Plant Sci 2020; 11:432. [PMID: 32351534 PMCID: PMC7175274 DOI: 10.3389/fpls.2020.00432] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
Thylakoid membranes, the site of photochemical and electron transport reactions of oxygenic photosynthesis, are composed of a myriad of proteins, cofactors including pigments, and glycerolipids. In the non-diazotrophic cyanobacterium Synechocystis sp. PCC 6803, the size and function of thylakoid membranes are reduced under nitrogen (N) starvation but are quickly recovered after N addition to the starved cells. To understand how the functionality of thylakoid membranes is adjusted in response to N status in Synechocystis sp. PCC 6803, we examined changes in thylakoid components and the photosynthetic activity during the N starvation and recovery processes. In N-starved cells, phycobilisome content, photosystem II protein levels and the photosynthetic activity substantially decreased as compared with those in N-sufficient cells. Although the content of chlorophyll (Chl) a, total protein and total glycerolipid also decreased under the N-starved condition based on OD730 reflecting cell density, when based on culture volume, the Chl a and total protein content remained almost constant and total glycerolipid content even increased during N starvation, suggesting that cellular levels of these components decrease under the N-starved condition mainly through dilution due to cell growth. With N addition, the photosynthetic activity quickly recovered, followed by full restoration of photosynthetic pigment and protein levels. The content of phosphatidylglycerol (PG), an essential lipid constituent of both photosystems, increased faster than that of Chl a, whereas the content of glycolipids, the main constituents of the thylakoid lipid bilayer, gradually recovered after N addition. The data indicate differential regulation of PG and glycolipids during the construction of the photosynthetic machinery and regeneration of thylakoid membranes. Of note, addition of PG to the growth medium slightly accelerated the Chl a accumulation in wild-type cells during the recovery process. Because PG is required for the biosynthesis of Chl a and the formation of functional photosystem complexes, rapid PG biosynthesis in response to N acquisition may be required for the rapid formation of the photosynthetic machinery during thylakoid regeneration.
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Affiliation(s)
- Koichi Kobayashi
- Faculty of Liberal Arts and Sciences, Osaka Prefecture University, Sakai, Japan
| | - Yuka Osawa
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka, Japan
| | - Akiko Yoshihara
- Department of Biological Sciences, School of Science, Osaka Prefecture University, Sakai, Japan
| | - Mie Shimojima
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Koichiro Awai
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka, Japan
- Research Institute of Electronics, Shizuoka University, Hamamatsu, Japan
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Kim B, Lee Y, Choi H, Huh WK. The trehalose-6-phosphate phosphatase Tps2 regulates ATG8 transcription and autophagy in Saccharomyces cerevisiae. Autophagy 2020; 17:1013-1027. [PMID: 32240040 DOI: 10.1080/15548627.2020.1746592] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Macroautophagy/autophagy is an important catabolic process for maintaining cellular homeostasis by adapting to various stress conditions. Autophagy is mediated by a double-membrane autophagosome, which sequesters a portion of cytoplasmic components for delivery to the vacuole. Several autophagy-related (ATG) genes play crucial roles in autophagosome formation. The induction of ATG genes must be tightly regulated to maintain a proper autophagic activity, but their regulatory mechanisms are still largely unknown. Here, we report that the trehalose-6-phosphate phosphatase Tps2 functions as a positive regulator of autophagy in Saccharomyces cerevisiae. Cellular trehalose levels do not affect autophagy regulation by Tps2. Loss of Tps2 leads to impaired autophagic flux and reduced ATG8 expre/ssion under nitrogen starvation. In tps2Δ cells, Ume6 is predominantly dephosphorylated and represses ATG8 transcription by binding to its promoter region. Tps2 regulates nuclear translocation and activation of Rim15 kinase, a negative regulator of Ume6, by causing the dissociation of Rim15 from the 14-3-3 proteins Bmh1/2 under nitrogen starvation, suggesting that Rim15 mediates the function of Tps2 as a positive regulator of ATG8 induction. Furthermore, Tps2 plays a crucial role in the dephosphorylation of Ser1061 and Thr1075 residues of Rim15, which is important for controlling the dissociation of Rim15 from Bmh1/2 under nitrogen starvation. Together, our results reveal the role of Tps2 as a positive regulator of autophagy and provide new insight into the regulatory mechanisms of ATG gene expression.Abbreviations: ATG: autophagy-related; ChIP: chromatin immunoprecipitation; Co-IP: co-immunoprecipitation; DAPI: 4',6-diamidino-2-phenylindole; GFP: green fluorescent protein; PKA: protein kinase A; PtdIns3K: phosphatidylinositol 3-kinase; Rim15KI: kinase-inactive Rim15; Rim15-2A: Rim15S1061A,T1075A; TEM: transmission electron microscopy; TORC1: target of rapamycin complex 1.
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Affiliation(s)
- Bongkeun Kim
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Yongook Lee
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Hyojeong Choi
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Won-Ki Huh
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,Institute of Microbiology, Seoul National University, Seoul, Republic of Korea
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Karim MR, Wang R, Zheng L, Dong X, Shen R, Lan P. Physiological and Proteomic Dissection of the Responses of Two Contrasting Wheat Genotypes to Nitrogen Deficiency. Int J Mol Sci 2020; 21:E2119. [PMID: 32204457 PMCID: PMC7139514 DOI: 10.3390/ijms21062119] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/13/2020] [Accepted: 03/14/2020] [Indexed: 01/18/2023] Open
Abstract
Nitrogen deficiency usually occurs along with aluminum toxicity in acidic soil, which is one of the major constraints for wheat production worldwide. In order to compare adaptive processes to N deficiency with different Al-tolerant wheat cultivars, we chose Atlas 66 and Scout 66 to comprehensively analyze the physiological responses to N deficiency, coupled with label-free mass spectrometry-based proteomics analysis. Results showed that both cultivars were comparable in most physiological indexes under N deficient conditions. However, the chlorophyll content in Scout 66 was higher than that of Atlas 66 under N deficiency. Further proteomic analysis identified 5592 and 5496 proteins in the leaves of Atlas 66 and Scout 66, respectively, of which 658 and 734 proteins were shown to significantly change in abundance upon N deficiency, respectively. The majority of the differentially expressed proteins were involved in cellular N compound metabolic process, photosynthesis, etc. Moreover, tetrapyrrole synthesis and sulfate assimilation were particularly enriched in Scout 66. Our findings provide evidence towards a better understanding of genotype-dependent responses under N deficiency which could help us to develop N efficient cultivars to various soil types.
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Affiliation(s)
- Mohammad Rezaul Karim
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (M.R.K.); (R.W.); (L.Z.); (X.D.); (R.S.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruonan Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (M.R.K.); (R.W.); (L.Z.); (X.D.); (R.S.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lu Zheng
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (M.R.K.); (R.W.); (L.Z.); (X.D.); (R.S.)
| | - Xiaoying Dong
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (M.R.K.); (R.W.); (L.Z.); (X.D.); (R.S.)
| | - Renfang Shen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (M.R.K.); (R.W.); (L.Z.); (X.D.); (R.S.)
| | - Ping Lan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (M.R.K.); (R.W.); (L.Z.); (X.D.); (R.S.)
- University of Chinese Academy of Sciences, Beijing 100049, China
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Yang C, Shen W, Yang L, Sun Y, Li X, Lai M, Wei J, Wang C, Xu Y, Li F, Liang S, Yang C, Zhong S, Luo M, Gao C. HY5-HDA9 Module Transcriptionally Regulates Plant Autophagy in Response to Light-to-Dark Conversion and Nitrogen Starvation. Mol Plant 2020; 13:515-531. [PMID: 32087368 DOI: 10.1016/j.molp.2020.02.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 05/02/2023]
Abstract
Light is arguably one of the most important environmental factors that determines virtually all aspects of plant growth and development, but the molecular link between light signaling and the autophagy pathway has not been elucidated in plants. In this study, we demonstrate that autophagy is activated during light-to-dark conversion though transcriptional upregulation of autophagy-related genes (ATGs). We showed that depletion of the ELONGATED HYPOCOTYL 5 (HY5), a key component of light signaling, leads to enhanced autophagy activity and resistance to extended darkness and nitrogen starvation treatments, contributing to higher expression of ATGs. HY5 interacts with and recruits HISTONE DEACETYLASE 9 (HDA9) to ATG5 and ATG8e loci to repress their expression by deacetylation of the Lys9 and Lys27 of histone 3. Furthermore, we found that both darkness and nitrogen depletion induce the degradation of HY5 via 26S proteasome and the concomitant disassociation of HDA9 from ATG5 and ATG8e loci, leading to their depression and thereby activated autophagy. Genetic analysis further confirmed that HY5 and HDA9 act synergistically and function upstream of the autophagy pathway. Collectively, our study unveils a previously unknown transcriptional and epigenetic network that regulates autophagy in response to light-to-dark conversion and nitrogen starvation in plants.
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Affiliation(s)
- Chao Yang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Wenjin Shen
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Lianming Yang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Yun Sun
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Xibao Li
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Minyi Lai
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Juan Wei
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Chaojun Wang
- College of Life Sciences, Leshan Normal University, Leshan 614004, China
| | - Yingchao Xu
- Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Faqiang Li
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Shan Liang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Chengwei Yang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Shangwei Zhong
- School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, 100871 Beijing, China
| | - Ming Luo
- Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China.
| | - Caiji Gao
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
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Conesa CM, Saez A, Navarro-Neila S, de Lorenzo L, Hunt AG, Sepúlveda EB, Baigorri R, Garcia-Mina JM, Zamarreño AM, Sacristán S, del Pozo JC. Alternative Polyadenylation and Salicylic Acid Modulate Root Responses to Low Nitrogen Availability. Plants (Basel) 2020; 9:E251. [PMID: 32079121 PMCID: PMC7076428 DOI: 10.3390/plants9020251] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/11/2020] [Accepted: 02/13/2020] [Indexed: 02/06/2023]
Abstract
Nitrogen (N) is probably the most important macronutrient and its scarcity limits plant growth, development and fitness. N starvation response has been largely studied by transcriptomic analyses, but little is known about the role of alternative polyadenylation (APA) in such response. In this work, we show that N starvation modifies poly(A) usage in a large number of transcripts, some of them mediated by FIP1, a component of the polyadenylation machinery. Interestingly, the number of mRNAs isoforms with poly(A) tags located in protein-coding regions or 5'-UTRs significantly increases in response to N starvation. The set of genes affected by APA in response to N deficiency is enriched in N-metabolism, oxidation-reduction processes, response to stresses, and hormone responses, among others. A hormone profile analysis shows that the levels of salicylic acid (SA), a phytohormone that reduces nitrate accumulation and root growth, increase significantly upon N starvation. Meta-analyses of APA-affected and fip1-2-deregulated genes indicate a connection between the nitrogen starvation response and salicylic acid (SA) signaling. Genetic analyses show that SA may be important for preventing the overgrowth of the root system in low N environments. This work provides new insights on how plants interconnect different pathways, such as defense-related hormonal signaling and the regulation of genomic information by APA, to fine-tune the response to low N availability.
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Affiliation(s)
- Carlos M. Conesa
- Centro de Biotecnología y Genómica de Plantas (CBGP), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain; (C.M.C.); (S.N.-N.)
- Centro de Biotecnología y Genómica de Plantas (CBGP) and Escuela Técnica Superior de Ingeniería Agronómica, Agroambiental y de Biosistemas (ETSIAAB), Universidad Polictécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain;
| | - Angela Saez
- DTD Development and Technical Department, Timac Agro Spain, 31580 Lodosa, Navarra, Spain; (A.S.); (R.B.)
| | - Sara Navarro-Neila
- Centro de Biotecnología y Genómica de Plantas (CBGP), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain; (C.M.C.); (S.N.-N.)
| | - Laura de Lorenzo
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312, USA; (L.d.L.); (A.G.H.)
| | - Arthur G. Hunt
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312, USA; (L.d.L.); (A.G.H.)
| | - Edgar B. Sepúlveda
- Departamento de Biotecnología y Bioingeniería CINVESTAV Instituto Politécnico Nacional, 07360 Ciudad de Mexico, Mexico;
| | - Roberto Baigorri
- DTD Development and Technical Department, Timac Agro Spain, 31580 Lodosa, Navarra, Spain; (A.S.); (R.B.)
| | - Jose M. Garcia-Mina
- Environmental Biology Department, University of Navarra, 31008 Navarra, Spain; (J.M.G.-M.); (A.M.Z.)
| | - Angel M. Zamarreño
- Environmental Biology Department, University of Navarra, 31008 Navarra, Spain; (J.M.G.-M.); (A.M.Z.)
| | - Soledad Sacristán
- Centro de Biotecnología y Genómica de Plantas (CBGP) and Escuela Técnica Superior de Ingeniería Agronómica, Agroambiental y de Biosistemas (ETSIAAB), Universidad Polictécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain;
| | - Juan C. del Pozo
- Centro de Biotecnología y Genómica de Plantas (CBGP), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain; (C.M.C.); (S.N.-N.)
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Vojtova J, Hasek J. Mmi1, the Yeast Ortholog of Mammalian Translationally Controlled Tumor Protein (TCTP), Negatively Affects Rapamycin-Induced Autophagy in Post-Diauxic Growth Phase. Cells 2020; 9:E138. [PMID: 31936125 DOI: 10.3390/cells9010138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/20/2019] [Accepted: 01/03/2020] [Indexed: 12/16/2022] Open
Abstract
Translationally controlled tumor protein (TCTP) is a multifunctional and highly conserved protein from yeast to humans. Recently, its role in non-selective autophagy has been reported with controversial results in mammalian and human cells. Herein we examine the effect of Mmi1, the yeast ortholog of TCTP, on non-selective autophagy in budding yeast Saccharomyces cerevisiae, a well-established model system to monitor autophagy. We induced autophagy by nitrogen starvation or rapamycin addition and measured autophagy by using the Pho8Δ60 and GFP-Atg8 processing assays in WT, mmi1Δ, and in autophagy-deficient strains atg8Δ or atg1Δ. Our results demonstrate that Mmi1 does not affect basal or nitrogen starvation-induced autophagy. However, an increased rapamycin-induced autophagy is detected in mmi1Δ strain when the cells enter the post-diauxic growth phase, and this phenotype can be rescued by inserted wild-type MMI1 gene. Further, the mmi1Δ cells exhibit significantly lower amounts of reactive oxygen species (ROS) in the post-diauxic growth phase compared to WT cells. In summary, our study suggests that Mmi1 negatively affects rapamycin-induced autophagy in the post-diauxic growth phase and supports the role of Mmi1/TCTP as a negative autophagy regulator in eukaryotic cells.
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Huo L, Guo Z, Zhang Z, Jia X, Sun Y, Sun X, Wang P, Gong X, Ma F. The Apple Autophagy-Related Gene MdATG9 Confers Tolerance to Low Nitrogen in Transgenic Apple Callus. Front Plant Sci 2020; 11:423. [PMID: 32351530 PMCID: PMC7174617 DOI: 10.3389/fpls.2020.00423] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 03/24/2020] [Indexed: 05/21/2023]
Abstract
Autophagy is an efficient degradation system for maintaining cellular homeostasis when plants are under environmental stress. ATG9 is the only integral membrane protein within the core ATG machinery that provides a membrane source for autophagosome formation. In this study, we isolated an ATG9 homologs gene in apple, MdATG9, from Malus domestica. The analysis of its sequence, subcellular localization, promoter cis-elements, and expression patterns revealed the potential function of MdATG9 in response to abiotic stressors. Overexpression of MdATG9 in apple callus conferred enhanced tolerance to nitrogen depletion stress. During the treatment, other important MdATGs were expressed at higher levels in transgenic callus than in the wild type. Furthermore, more free amino acids and increased sucrose levels were found in MdATG9-overexpression apple callus compared with the wild type in response to nitrogen starvation, and the expression levels of MdNRT1.1, MdNRT2.5, MdNIA1, and MdNIA2 were all increased higher in transgenic lines. These data suggest that, as an important autophagy gene, MdATG9 plays an important role in the maintenance of amino acids and sugars in response to nutrient starvation in apple.
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