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Pan Y, Zhang W, Wang X, Jouhet J, Maréchal E, Liu J, Xia XQ, Hu H. Allele-dependent expression and functionality of lipid enzyme phospholipid:diacylglycerol acyltransferase affect diatom carbon storage and growth. PLANT PHYSIOLOGY 2024; 194:1024-1040. [PMID: 37930282 DOI: 10.1093/plphys/kiad581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/06/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023]
Abstract
In the acyl-CoA-independent pathway of triacylglycerol (TAG) synthesis unique to plants, fungi, and algae, TAG formation is catalyzed by the enzyme phospholipid:diacylglycerol acyltransferase (PDAT). The unique PDAT gene of the model diatom Phaeodactylum tricornutum strain CCMP2561 boasts 47 single nucleotide variants within protein coding regions of the alleles. To deepen our understanding of TAG synthesis, we observed the allele-specific expression of PDAT by the analysis of 87 published RNA-sequencing (RNA-seq) data and experimental validation. The transcription of one of the two PDAT alleles, Allele 2, could be specifically induced by decreasing nitrogen concentrations. Overexpression of Allele 2 in P. tricornutum substantially enhanced the accumulation of TAG by 44% to 74% under nutrient stress; however, overexpression of Allele 1 resulted in little increase of TAG accumulation. Interestingly, a more serious growth inhibition was observed in the PDAT Allele 1 overexpression strains compared with Allele 2 counterparts. Heterologous expression in yeast (Saccharomyces cerevisiae) showed that enzymes encoded by PDAT Allele 2 but not Allele 1 had TAG biosynthetic activity, and 7 N-terminal and 3 C-terminal amino acid variants between the 2 allele-encoded proteins substantially affected enzymatic activity. P. tricornutum PDAT, localized in the innermost chloroplast membrane, used monogalactosyldiacylglycerol and phosphatidylcholine as acyl donors as demonstrated by the increase of the 2 lipids in PDAT knockout lines, which indicated a common origin in evolution with green algal PDATs. Our study reveals unequal roles among allele-encoded PDATs in mediating carbon storage and growth in response to nitrogen stress and suggests an unsuspected strategy toward lipid and biomass improvement for biotechnological purposes.
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Affiliation(s)
- Yufang Pan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wanting Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xiaofei Wang
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV, Grenoble Cedex 9 38054, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV, Grenoble Cedex 9 38054, France
| | - Jin Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Xiao-Qin Xia
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hanhua Hu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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Xu Y, Jin Y, He D, Di H, Liang Y, Xu Y. A Genome-Wide Analysis and Expression Profile of Heat Shock Transcription Factor (Hsf) Gene Family in Rhododendron simsii. PLANTS (BASEL, SWITZERLAND) 2023; 12:3917. [PMID: 38005814 PMCID: PMC10674592 DOI: 10.3390/plants12223917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/01/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023]
Abstract
Heat shock transcription factors are key players in a number of transcriptional regulatory pathways that function during plant growth and development. However, their mode of action in Rhododendron simsii is still unclear. In this study, 22 RsHsf genes were identified from genomic data of R. simsii. The 22 genes were randomly distributed on 12 chromosomes, and were divided into three major groups according to their phylogenetic relationships. The structures and conserved motifs were predicted for the 22 genes. Analysis of cis-acting elements revealed stress-responsive and phytohormone-responsive elements in the gene promoter regions, but the types and number varied among the different groups of genes. Transcriptional profile analyses revealed that RsHsfs were expressed in a tissue-specific manner, with particularly high transcript levels in the roots. The transcriptional profiles under abiotic stress were detected by qRT-PCR, and the results further validated the critical function of RsHsfs. This study provides basic information about RsHsf family in R. simsii, and paves the way for further research to clarify their precise roles and to breed new stress-tolerant varieties.
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Affiliation(s)
- Yanan Xu
- Jiyang College, Zhejiang A&F University, Zhuji 311800, China; (Y.X.); (H.D.); (Y.L.)
- College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou 311300, China
| | - Ying Jin
- Zhuji Economic Specialty Station, Zhuji 311800, China; (Y.J.); (D.H.)
| | - Dan He
- Zhuji Economic Specialty Station, Zhuji 311800, China; (Y.J.); (D.H.)
| | - Haochen Di
- Jiyang College, Zhejiang A&F University, Zhuji 311800, China; (Y.X.); (H.D.); (Y.L.)
| | - Ying Liang
- Jiyang College, Zhejiang A&F University, Zhuji 311800, China; (Y.X.); (H.D.); (Y.L.)
| | - Yanxia Xu
- Jiyang College, Zhejiang A&F University, Zhuji 311800, China; (Y.X.); (H.D.); (Y.L.)
- Zhuji Economic Specialty Station, Zhuji 311800, China; (Y.J.); (D.H.)
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Shu Q, Pan Y, Hu H. CGI-58 Protein Acts as a Positive Regulator of Triacylglycerol Accumulation in Phaeodactylum tricornutum. J Microbiol Biotechnol 2023; 33:242-250. [PMID: 36524337 PMCID: PMC9998212 DOI: 10.4014/jmb.2209.09029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022]
Abstract
Comparative gene identification-58 (CGI-58) is an activating protein of triacylglycerol (TAG) lipase. It has a variety of catalytic activities whereby it may play different roles in diverse organisms. In this study, a homolog of CGI-58 in Phaeodactylum tricornutum (PtCGI-58) was identified. PtCGI-58 was localized in mitochondria by GFP fusion protein analysis, which is different from the reported subcellular localization of CGI-58 in animals and plants. Respectively, PtCGI-58 overexpression resulted in increased neutral lipid content and TAG accumulation by 42-46% and 21-32%. Likewise, it also increased the relative content of eicosapentaenoic acid (EPA), and in particular, the EPA content in TAGs almost doubled. Transcript levels of genes involved in de novo fatty acid synthesis and mitochondrial β-oxidation were significantly upregulated in PtCGI-58 overexpression strains compared with wild-type cells. Our findings suggest that PtCGI-58 may mediate the breakdown of lipids in mitochondria and the recycling of acyl chains derived from mitochondrial β-oxidation into TAG biosynthesis. Moreover, this study potentially illuminates new functions for CGI-58 in lipid homeostasis and provides a strategy to enrich EPA in algal TAGs.
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Affiliation(s)
- Qin Shu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China.,University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Yufang Pan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China
| | - Hanhua Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China
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NmrA acts as a positive regulator of nitrate assimilation in Phaeodactylum tricornutum. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Abassi S, Ki JS. Increased nitrate concentration differentially affects cell growth and expression of nitrate transporter and other nitrogen-related genes in the harmful dinoflagellate Prorocentrum minimum. CHEMOSPHERE 2022; 288:132526. [PMID: 34637868 DOI: 10.1016/j.chemosphere.2021.132526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/29/2021] [Accepted: 10/08/2021] [Indexed: 06/13/2023]
Abstract
The molecular mechanisms through which dinoflagellates adapt to nitrate fluctuations in aquatic environments remain poorly understood. Here, we sequenced the full-length cDNA of a nitrate transporter (NRT) gene from the harmful marine dinoflagellate Prorocentrum minimum Schiller. The cDNA length was 2431 bp. It encoded a 529-amino acid protein, which was phylogenetically clustered with proteins from other dinoflagellates. Nitrate supply promoted cell growth up to a certain concentration (∼1.76 mM) but inhibited it at higher concentrations. Interestingly, at the inhibitory concentrations, nitrite levels in the medium were considerably increased. Nitrate concentration affected the expression of PmNRT, nitrite transporter (PmNiRT), nitrate reductase (PmNR), and nitrite reductase (PmNiR). Specifically, PmNRT was upregulated after 24 h, with ∼6-fold change compared with the control level, in both nitrate-depleted and nitrate-repleted cultures. In addition, PmNR transcript levels increased to the maximum of 4-fold at 48 h but decreased thereafter. In contrast, PmNiR levels remained unchanged in both nitrate-repleted and nitrate-depleted cultures. Therefore, P. minimum likely copes with nitrate fluctuations in its environment by regulating a set of genes responsible for nitrate uptake.
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Affiliation(s)
- Sofia Abassi
- Department of Biotechnology, Sangmyung University, Seoul, 03016, South Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul, 03016, South Korea.
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Zhang Q, Geng J, Du Y, Zhao Q, Zhang W, Fang Q, Yin Z, Li J, Yuan X, Fan Y, Cheng X, Du J. Heat shock transcription factor (Hsf) gene family in common bean (Phaseolus vulgaris): genome-wide identification, phylogeny, evolutionary expansion and expression analyses at the sprout stage under abiotic stress. BMC PLANT BIOLOGY 2022; 22:33. [PMID: 35031009 PMCID: PMC8759166 DOI: 10.1186/s12870-021-03417-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 12/28/2021] [Indexed: 05/03/2023]
Abstract
BACKGROUND Common bean (Phaseolus vulgaris) is an essential crop with high economic value. The growth of this plant is sensitive to environmental stress. Heat shock factor (Hsf) is a family of antiretroviral transcription factors that regulate plant defense system against biotic and abiotic stress. To date, few studies have identified and bio-analyzed Hsfs in common bean. RESULTS In this study, 30 Hsf transcription factors (PvHsf1-30) were identified from the PFAM database. The PvHsf1-30 belonged to 14 subfamilies with similar motifs, gene structure and cis-acting elements. The Hsf members in Arabidopsis, rice (Oryza sativa), maize (Zea mays) and common bean were classified into 14 subfamilies. Collinearity analysis showed that PvHsfs played a role in the regulation of responses to abiotic stress. The expression of PvHsfs varied across different tissues. Moreover, quantitative real-time PCR (qRT-PCR) revealed that most PvHsfs were differentially expressed under cold, heat, salt and heavy metal stress, indicating that PvHsfs might play different functions depending on the type of abiotic stress. CONCLUSIONS In this study, we identified 30 Hsf transcription factors and determined their location, motifs, gene structure, cis-elements, collinearity and expression patterns. It was found that PvHsfs regulates responses to abiotic stress in common bean. Thus, this study provides a basis for further analysis of the function of PvHsfs in the regulation of abiotic stress in common bean.
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Affiliation(s)
- Qi Zhang
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
| | - Jing Geng
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
| | - Yanli Du
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
- National Coarse Cereals Engineering Research Center, Daqing, 161139, Heilongjiang, China
| | - Qiang Zhao
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
| | - Wenjing Zhang
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
| | - Qingxi Fang
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
| | - Zhengong Yin
- Crop Resources Institute of Heilongjiang Academy of Agricultural Sciences, Harbin, 150086, Heilongjiang, China
| | - Jianghui Li
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
| | - Xiankai Yuan
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
| | - Yaru Fan
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
| | - Xin Cheng
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China
| | - Jidao Du
- College of Agriculture, Heilongjiang BaYi Agricultural University, Daqing, 163319, Heilongjaing, China.
- National Coarse Cereals Engineering Research Center, Daqing, 161139, Heilongjiang, China.
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Ding H, Qian L, Jiang H, Ji Y, Fang Y, Sheng J, Xu X, Ge C. Overexpression of a Bcl-2-associated athanogene SlBAG9 negatively regulates high-temperature response in tomato. Int J Biol Macromol 2022; 194:695-705. [PMID: 34822834 DOI: 10.1016/j.ijbiomac.2021.11.114] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/07/2021] [Accepted: 11/16/2021] [Indexed: 12/18/2022]
Abstract
The Bcl-2-associated athanogene (BAG) gene is a multi-functional family of co-chaperones regulator, modulating plant stress response. Our previous study revealed that the SlBAG9 of tomato (Solanum lycopersicum) had the higher expression level induced by high-temperature (HT) at the transcriptional and protein levels, but its biological function was still unclear. Here, we conducted an in-depth analysis of SlBAG9. SlBAG9 protein was not located in the mitochondria but in the cytoplasm and nucleus. Many cis-acting elements involved in plant stress and hormone responses were located in the promoter regions of SlBAG9 including heat-shock element (HSE1). The β-glucuronidase (GUS) histochemical analysis showed that SlBAG9 promoter could drive GUS gene expression in transiently transformed Nicotiana tabacum leaves under non-inducing condition and HSE1 is critical for HT-induced GUS activity under HT. The transcription of SlBAG9 was expressed in different organs and was regulated by HT, cold, drought, and salt stresses as well as exogenous abscisic acid (ABA) and H2O2. To further elucidate SlBAG9 function in response to HT, the transgenic tomato plants overexpressing SlBAG9 were developed. Compared to the wild-type plants, SlBAG9-overexpressing plants exhibited more sensitivity to HT stress, reflected by the burning symptoms, the degradation of chlorophyll, and the reduction of photosynthetic rates. Additionally, SlBAG9-overexpressing lines showed higher accumulation of lipid peroxidation production (MDA) and H2O2, but lower activities of superoxide dismutase, catalase, and peroxidase. Therefore, it is speculated that SlBAG9 plays a negative role in thermotolerance probably by inhibition of antioxidant enzyme system leading to the oxidative damage, consequently aggravating the HT-caused injury phenotype.
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Affiliation(s)
- Haidong Ding
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China.
| | - Lu Qian
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Hailong Jiang
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Yurong Ji
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Yifang Fang
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Jiarong Sheng
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Xiaoying Xu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Cailin Ge
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
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Erdene‐Ochir E, Shin B, Huda MN, Lee EH, Song D, Jung C, Pan C. Characterization of endogenous promoters of GapC1 and GS for recombinant protein expression in Phaeodactylum tricornutum. Microbiologyopen 2021; 10:e1239. [PMID: 34713604 PMCID: PMC8545674 DOI: 10.1002/mbo3.1239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 09/14/2021] [Indexed: 11/11/2022] Open
Abstract
Although diatoms have been utilized as a cellular factory to produce biopharmaceuticals, recombinant proteins, and biofuels, only a few numbers of gene promoters are available. Therefore, the development of novel endogenous promoters is essential for the production of a range of bioactive substances. Here, we characterized the activities of endogenous promoters glyceraldehyde-3-phosphate dehydrogenase (GapC1) and glutamine synthetase (GS) of Phaeodactylum tricornutum using green fluorescent protein (GFP) under different culture conditions. Compared with the widely used fucoxanthin chlorophyll-binding protein A (fcpA) promoter, the GS promoter constitutively drove the expression of GFP throughout all growth phases of P. tricornutum, regardless of culture conditions. Additionally, the GFP level driven by the GapC1 promoter was the highest at the log phase, similar to the fcpA promoter, and increased light and nitrogen-starvation conditions reduced GFP levels by inhibiting promoter activity. These results suggested that the GS promoter could be utilized as a strong endogenous promoter for the genetic engineering of P. tricornutum.
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Affiliation(s)
- Erdenedolgor Erdene‐Ochir
- Natural Product Informatics Research CenterKIST Gangneung Institute of Natural ProductsGangneungRepublic of Korea
- Division of Bio‐Medical Science and Technology, KIST SchoolKorea University of Science and TechnologySeoulRepublic of Korea
| | | | - Md Nazmul Huda
- Natural Product Informatics Research CenterKIST Gangneung Institute of Natural ProductsGangneungRepublic of Korea
- Division of Bio‐Medical Science and Technology, KIST SchoolKorea University of Science and TechnologySeoulRepublic of Korea
| | - Eun Ha Lee
- Natural Product Informatics Research CenterKIST Gangneung Institute of Natural ProductsGangneungRepublic of Korea
| | - Dae‐Geun Song
- Natural Product Informatics Research CenterKIST Gangneung Institute of Natural ProductsGangneungRepublic of Korea
| | - Choonkyun Jung
- Department of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and TechnologySeoul National UniversityPyeongchangRepublic of Korea
- Department of Agriculture, Forestry, and Bioresources and Integrated Major in Global Smart Farm, College of Agriculture and Life SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Cheol‐Ho Pan
- Natural Product Informatics Research CenterKIST Gangneung Institute of Natural ProductsGangneungRepublic of Korea
- Division of Bio‐Medical Science and Technology, KIST SchoolKorea University of Science and TechnologySeoulRepublic of Korea
- Microalgae Ask Us Co., Ltd.GangneungRepublic of Korea
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Rastogi A, Lin X, Lombard B, Loew D, Tirichine L. Probing the evolutionary history of epigenetic mechanisms: what can we learn from marine diatoms. AIMS GENETICS 2021. [DOI: 10.3934/genet.2015.3.173] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
AbstractRecent progress made on epigenetic studies revealed the conservation of epigenetic features in deep diverse branching species including Stramenopiles, plants and animals. This suggests their fundamental role in shaping species genomes across different evolutionary time scales. Diatoms are a highly successful and diverse group of phytoplankton with a fossil record of about 190 million years ago. They are distantly related from other super-groups of Eukaryotes and have retained some of the epigenetic features found in mammals and plants suggesting their ancient origin. Phaeodactylum tricornutum and Thalassiosira pseudonana, pennate and centric diatoms, respectively, emerged as model species to address questions on the evolution of epigenetic phenomena such as what has been lost, retained or has evolved in contemporary species. In the present work, we will discuss how the study of non-model or emerging model organisms, such as diatoms, helps understand the evolutionary history of epigenetic mechanisms with a particular focus on DNA methylation and histone modifications.
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Affiliation(s)
- Achal Rastogi
- Ecology and Evolutionary Biology Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR8197 INSERM U1024, 46 rue d’Ulm 75005 Paris, France
| | - Xin Lin
- Ecology and Evolutionary Biology Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR8197 INSERM U1024, 46 rue d’Ulm 75005 Paris, France
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China
| | - Bérangère Lombard
- Institut Curie, PSL Research University, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 26 rue d’Ulm 75248 Cedex 05 Paris, France
| | - Damarys Loew
- Institut Curie, PSL Research University, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 26 rue d’Ulm 75248 Cedex 05 Paris, France
| | - Leïla Tirichine
- Ecology and Evolutionary Biology Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR8197 INSERM U1024, 46 rue d’Ulm 75005 Paris, France
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10
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Zhao X, Rastogi A, Deton Cabanillas AF, Ait Mohamed O, Cantrel C, Lombard B, Murik O, Genovesio A, Bowler C, Bouyer D, Loew D, Lin X, Veluchamy A, Vieira FRJ, Tirichine L. Genome wide natural variation of H3K27me3 selectively marks genes predicted to be important for cell differentiation in Phaeodactylum tricornutum. THE NEW PHYTOLOGIST 2021; 229:3208-3220. [PMID: 33533496 DOI: 10.1111/nph.17129] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/24/2020] [Indexed: 05/28/2023]
Abstract
In multicellular organisms, Polycomb Repressive Complex2 (PRC2) is known to deposit tri-methylation of lysine 27 of histone H3 (H3K27me3) to establish and maintain gene silencing, critical for developmentally regulated processes. The PRC2 complex is absent in both widely studied model yeasts, which initially suggested that PRC2 arose with the emergence of multicellularity. However, its discovery in several unicellular species including microalgae questions its role in unicellular eukaryotes. Here, we use Phaeodactylum tricornutum enhancer of zeste E(z) knockouts and show that P. tricornutum E(z) is responsible for di- and tri-methylation of lysine 27 of histone H3. H3K27me3 depletion abolishes cell morphology in P. tricornutum providing evidence for its role in cell differentiation. Genome-wide profiling of H3K27me3 in fusiform and triradiate cells further revealed genes that may specify cell identity. These results suggest a role for PRC2 and its associated mark in cell differentiation in unicellular species, and highlight their ancestral function in a broader evolutionary context than currently is appreciated.
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Affiliation(s)
- Xue Zhao
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
- CNRS UMR6286, UFIP UFR Sciences et Techniques, Université de Nantes, 2 rue de la Houssinière 44322, Nantes Cedex 03, France
| | - Achal Rastogi
- Corteva AgriscienceTM, Ascendas IT Park, 12th floor, Atria, V, Madhapur, Telangana, 500081, India
| | - Anne Flore Deton Cabanillas
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Ouardia Ait Mohamed
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Catherine Cantrel
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Berangère Lombard
- Laboratoire de Spectrométrie de Masse Protéomique, Centre de Recherche, Institut Curie, PSL Research University, 26 rue d'Ulm, Cedex 05 Paris, 75248, France
| | - Omer Murik
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Auguste Genovesio
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Chris Bowler
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Daniel Bouyer
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Damarys Loew
- Laboratoire de Spectrométrie de Masse Protéomique, Centre de Recherche, Institut Curie, PSL Research University, 26 rue d'Ulm, Cedex 05 Paris, 75248, France
| | - Xin Lin
- State Key Laboratory of Marine Environmental Science, Centre de Recherche, College of Ocean Camp; Earth Sciences,, Xiamen University, Xiamen, 361102, China
| | - Alaguraj Veluchamy
- Laboratory of Chromatin Biochemistry, 4700 King Abdullah University of Science and Technology (KAUST), BESE Division Building 2, Level 3, Office B2-3327, Thuwal, 23955-6900, Saudi Arabia
| | - Fabio Rocha Jimenez Vieira
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Leila Tirichine
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
- CNRS UMR6286, UFIP UFR Sciences et Techniques, Université de Nantes, 2 rue de la Houssinière 44322, Nantes Cedex 03, France
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Shi X, Xiao Y, Liu L, Xie Y, Ma R, Chen J. Transcriptome responses of the dinoflagellate Karenia mikimotoi driven by nitrogen deficiency. HARMFUL ALGAE 2021; 103:101977. [PMID: 33980427 DOI: 10.1016/j.hal.2021.101977] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
The availability of ambient N nutrient is often correlated with the occurrences of harmful algal bloom formed by certain dinoflagellates, making it important to understand how these species might be responding to such conditions. Here, transcriptome sequencing of Karenia mikimotoi was conducted to understand the underlying molecular mechanisms by which this dinoflagellate copes with nitrogen (N) deficiency. Transcriptomic analysis revealed 8802 unigenes (3.56%) that were differentially expressed with ≥ 2-fold change. Under N-depleted conditions, genes involved in glycolysis, fatty acid metabolism, and the tricarboxylic acid (TCA) cycle as well as lipid accumulation were significantly upregulated. The elevated expression of enzymes used in protein degradation and turnover suggests possible metabolic reconfiguration towards accelerated N recycling. Moreover, a significant increase in urea transporter was observed, indicating increased assimilation of organic nitrogen resources as an alternative in N-depleted cultures of K. mikimotoi. The down-regulated glutamate synthase genes were also identified under N deficiency, suggesting suppression of primary amino acid synthesis to save N resource. Taken together, results of this study show enhanced multiple N resource acquisition and reuse of multiple N resources constitute a comprehensive strategy to cope with N deficiency in a dinoflagellate.
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Affiliation(s)
- Xinguo Shi
- Fujian Engineering Research Center for Comprehensive Utilization of Marine Products Waste, Fuzhou University, Fujian 350116, China; Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fujian 350116, China.
| | - Yuchun Xiao
- Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fujian 350116, China
| | - Lemian Liu
- Fujian Engineering Research Center for Comprehensive Utilization of Marine Products Waste, Fuzhou University, Fujian 350116, China; Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fujian 350116, China
| | - Youping Xie
- Fujian Engineering Research Center for Comprehensive Utilization of Marine Products Waste, Fuzhou University, Fujian 350116, China; Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fujian 350116, China
| | - Ruijuan Ma
- Fujian Engineering Research Center for Comprehensive Utilization of Marine Products Waste, Fuzhou University, Fujian 350116, China; Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fujian 350116, China
| | - Jianfeng Chen
- Fujian Engineering Research Center for Comprehensive Utilization of Marine Products Waste, Fuzhou University, Fujian 350116, China; Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fujian 350116, China.
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12
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Ma J, Zhou B, Chen F, Pan K. How marine diatoms cope with metal challenge: Insights from the morphotype-dependent metal tolerance in Phaeodactylum tricornutum. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111715. [PMID: 33396046 DOI: 10.1016/j.ecoenv.2020.111715] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 11/14/2020] [Accepted: 11/22/2020] [Indexed: 06/12/2023]
Abstract
Metal tolerance in marine diatoms vary between morphotypes, strains, and species due to their long-term adaptations to stochastic environments. The mechanisms underlying this highly variable trait remain a matter of interest in ecotoxicology. In this study, we used several cutting-edge techniques, including a non-invasive micro-test technique, atomic force microscopy, and X-ray photoelectron spectroscopy to examine cadmium (Cd) accumulation and tolerance in the three morphotypes of Phaeodactylum tricornutum. Subcellular Cd distribution, metal transporter expression, and glutathione and phytochelatin activity were also analyzed to characterize the morphology-dependent Cd homeostasis and detoxification. We found that the oval morphotype accumulated more Cd, but was also more Cd tolerant than the other morphotypes. The greater surface binding of Cd to the oval morphotype is attributable to its smaller spherical form, rougher cell surface, and lower surface potential. Moreover, the oval morphotype was less permeable to Cd ions and contained higher phytochelatin and glutathione levels, which explained its higher metal tolerance. Our study offers new explanations for diatom's adaptations to changing environments that may contribute to its evolutionary success.
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Affiliation(s)
- Jie Ma
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Beibei Zhou
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Fengyuan Chen
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Ke Pan
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
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13
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Sexual reproduction potential implied by functional analysis of SPO11 in Phaeodactylum tricornutum. Gene 2020; 757:144929. [PMID: 32622990 DOI: 10.1016/j.gene.2020.144929] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 06/19/2020] [Accepted: 06/27/2020] [Indexed: 01/05/2023]
Abstract
Phaeodactylum tricornutum is a model microalgae that is widely used to study diatom physiology and ecology. Since the meiotic process and sexual cycle have never been observed directly, P. tricornutum has been considered to be an asexual species. However, phylogenetic analysis of the P. tricornutum genome has revealed a series of meiosis-specific gene homologues in this species. We identified two copies of differently transcribed SPO11 homologs that contain the conserved motifs of Winged-helix and Toprim domains. The homolog PtSPO11-3 interacts with TopoVIB in yeast two-hybrid analysis, whereas the homolog PtSPO11-2 could rescue the sporulation defect of a Spo11 yeast mutant strain. PtSPO11-2 was also found to be significantly up-regulated at low temperatures in P. tricornutum and its key catalytic residue was important to the homolog's function in sporulation. The results herein provide positive clue that meiosis and sexual reproduction could exist in this diatom.
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14
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Zhang X, Xu W, Ni D, Wang M, Guo G. Genome-wide characterization of tea plant (Camellia sinensis) Hsf transcription factor family and role of CsHsfA2 in heat tolerance. BMC PLANT BIOLOGY 2020; 20:244. [PMID: 32471355 PMCID: PMC7260767 DOI: 10.1186/s12870-020-02462-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 05/24/2020] [Indexed: 05/02/2023]
Abstract
BACKGROUND Heat stress factors (Hsfs) play vital roles in signal transduction pathways operating in responses to environmental stresses. However, Hsf gene family has not been thoroughly explored in tea plant (Camellia sinensis L.). RESULTS In this study, we identified 25 CsHsf genes in C. sinensis that were separated by phylogenetic analysis into three sub-families (i.e., A, B, and C). Gene structures, conserved domains and motifs analyses indicated that the CsHsf members in each class were relatively conserved. Various cis-acting elements involved in plant growth regulation, hormone responses, stress responses, and light responses were located in the promoter regions of CsHsfs. Furthermore, degradome sequencing analysis revealed that 7 CsHsfs could be targeted by 9 miRNAs. The expression pattern of each CsHsf gene was significantly different in eight tissues. Many CsHsfs were differentially regulated by drought, salt, and heat stresses, as well as exogenous abscisic acid (ABA) and Ca2+. In addition, CsHsfA2 was located in the nucleus. Heterologous expression of CsHsfA2 improved thermotolerance in transgenic yeast, suggesting its potential role in the regulation of heat stress response. CONCLUSIONS A comprehensive genome-wide analysis of Hsf in C. sinensis present the global identification and functional prediction of CsHsfs. Most of them were implicated in a complex gene regulatory network controlling various abiotic stress responses and signal transduction pathways in tea plants. Additionally, heterologous expression of CsHsfA2 increased thermotolerance of transgenic yeast. These findings provide new insights into the functional divergence of CsHsfs and a basis for further research on CsHsfs functions.
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Affiliation(s)
- Xuyang Zhang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Shizishan No. 1, Wuhan, 430070 Hubei Province P. R. China
| | - Wenluan Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Shizishan No. 1, Wuhan, 430070 Hubei Province P. R. China
| | - Dejiang Ni
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Shizishan No. 1, Wuhan, 430070 Hubei Province P. R. China
| | - Mingle Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Shizishan No. 1, Wuhan, 430070 Hubei Province P. R. China
| | - Guiyi Guo
- Henan Key Laboratory of Tea Plant Comprehensive Utilization in South Henan, Xinyang Agriculture and Forestry University, Xinyang, 464000 China
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15
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Early dynamics of photosynthetic Lhcf2 and Lhcf15 transcription and mRNA stabilities in response to herbivory-related decadienal in Phaeodactylum tricornutum. Sci Rep 2020; 10:2029. [PMID: 32029835 PMCID: PMC7005025 DOI: 10.1038/s41598-020-58885-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 01/21/2020] [Indexed: 12/31/2022] Open
Abstract
Abiotic and biotic stresses widely reduce light harvesting complex (LHC) gene expression in higher plants and algae. However, control mechanisms and functions of these changes are not well understood. During herbivory, marine diatom species release oxylipins that impair grazer reproduction and serve as signaling molecules to nearby undamaged diatoms. To examine LHC mRNA regulation by oxylipin exposure, the diatom Phaeodactylum tricornutum was treated with a sublethal concentration of trans,trans-2,4-decadienal (DD) during the light cycle. Transcriptome analyses revealed extensive suppression of LHC mRNAs and a smaller set of up-regulated LHC mRNAs at 3 h. For two divergently regulated LHCF antennae family mRNAs, in vivo 4-thiouracil metabolic labeling was used to distinguish synthesis and degradation rates. Within 3 h of DD exposure, Lhcf2 mRNA levels and transcription were strongly suppressed and its mRNA half-life decreased. In contrast, Lhcf15 mRNA mainly accumulated between 3-9 h, its transcription increased and its mRNA was highly stabilized. Hence, DD-treated cells utilized transcriptional and mRNA stability control mechanisms which were likely major factors in the differing Lhcf2 and Lhcf15 expression patterns. Widespread LHC mRNA regulation and possible effects on photosynthesis may contribute to enhanced fitness in cells impacted by herbivory and other stresses.
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16
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Pechkovskaya SA, Knyazev NA, Matantseva OV, Emelyanov AK, Telesh IV, Skarlato SO, Filatova NA. Dur3 and nrt2 genes in the bloom-forming dinoflagellate Prorocentrum minimum: Transcriptional responses to available nitrogen sources. CHEMOSPHERE 2020; 241:125083. [PMID: 31683425 DOI: 10.1016/j.chemosphere.2019.125083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/06/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
The increasing inflow of nitrogen (N) substrates into marine nearshore ecosystems induces proliferation of harmful algal blooms (HABs) of dinoflagellates, such as potentially toxic invasive species Prorocentrum minimum. In this study, we estimated the influence of NO3-, NH4+ and urea on transcription levels and urea transporter dur3 and nitrate transporter nrt2 genes expression in these dinoflagellates. We identified dur3 and nrt2 genes sequences in unannotated transcriptomes of P. minimum and other dinoflagellates presented in MMETSP database. Phylogenetic analysis showed that these genes of dinoflagellates clustered to the distinct clade demonstrating evolutionary relationship with the other known dur3 and nrt2 genes of microalgae. The evaluation of expression levels of dur3 and nrt2 genes by RT-qPCR revealed their sensitivity to input of the studied N sources. Dur3 expression levels were downregulated after the supplementation of additional N sources and were 1.7-2.6-fold lower than in the nitrate-grown culture. Nrt2 expression levels decreased 1.9-fold in the presence of NH4+. We estimated total RNA and DNA synthesis rates by the analysis of incorporation of 3H-thymidine and 3H-uridine in batch and continuous cultures. Addition of N compounds did not affect the DNA synthesis rates. Transcription levels increased up to 12.5-fold after the N supplementation in urea-limited treatments. Investigation of various nitrogen sources as biomarkers of dinoflagellate proliferation due to their differentiated impact on expression of dur3 and nrt2 genes and transcription rates in P. minimum cells allowed concluding about high potential of the studied parameters for future modeling of HABs under global N pollution.
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Affiliation(s)
- S A Pechkovskaya
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - N A Knyazev
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia; St. Petersburg Academic University of Nanotechnology Research and Education Centre, St. Petersburg, Russia
| | - O V Matantseva
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - A K Emelyanov
- Pavlov First State Medical University of St. Petersburg, St. Petersburg, Russia
| | - I V Telesh
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia; Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia.
| | - S O Skarlato
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - N A Filatova
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
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17
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Rastogi A, Vieira FRJ, Deton-Cabanillas AF, Veluchamy A, Cantrel C, Wang G, Vanormelingen P, Bowler C, Piganeau G, Hu H, Tirichine L. A genomics approach reveals the global genetic polymorphism, structure, and functional diversity of ten accessions of the marine model diatom Phaeodactylum tricornutum. THE ISME JOURNAL 2020; 14:347-363. [PMID: 31624346 PMCID: PMC6976637 DOI: 10.1038/s41396-019-0528-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/24/2019] [Accepted: 09/11/2019] [Indexed: 12/31/2022]
Abstract
Diatoms emerged in the Mesozoic period and presently constitute one of the main primary producers in the world's ocean and are of a major economic importance. In the current study, using whole genome sequencing of ten accessions of the model diatom Phaeodactylum tricornutum, sampled at broad geospatial and temporal scales, we draw a comprehensive landscape of the genomic diversity within the species. We describe strong genetic subdivisions of the accessions into four genetic clades (A-D) with constituent populations of each clade possessing a conserved genetic and functional makeup, likely a consequence of the limited dispersal of P. tricornutum in the open ocean. We further suggest dominance of asexual reproduction across all the populations, as implied by high linkage disequilibrium. Finally, we show limited yet compelling signatures of genetic and functional convergence inducing changes in the selection pressure on many genes and metabolic pathways. We propose these findings to have significant implications for understanding the genetic structure of diatom populations in nature and provide a framework to assess the genomic underpinnings of their ecological success and impact on aquatic ecosystems where they play a major role. Our work provides valuable resources for functional genomics and for exploiting the biotechnological potential of this model diatom species.
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Affiliation(s)
- Achal Rastogi
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
- Corteva Agriscience™, The V Ascendas, Atria Block, 12th Floor, Madhapur, Hyderabad, 500081, India
| | - Fabio Rocha Jimenez Vieira
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Anne-Flore Deton-Cabanillas
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Alaguraj Veluchamy
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
- Biological and Environmental Sciences and Engineering Division, Center for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Catherine Cantrel
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Gaohong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, 430072, Wuhan, China
| | - Pieter Vanormelingen
- Department of Biology, Research Group Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281/S8 9000, Gent, Belgium
| | - Chris Bowler
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Gwenael Piganeau
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650, Banyuls/Mer, France
| | - Hanhua Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, 430072, Wuhan, China.
| | - Leila Tirichine
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France.
- Université de Nantes, CNRS, UFIP, UMR 6286, F-44000, Nantes, France.
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18
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Ait-Mohamed O, Novák Vanclová AMG, Joli N, Liang Y, Zhao X, Genovesio A, Tirichine L, Bowler C, Dorrell RG. PhaeoNet: A Holistic RNAseq-Based Portrait of Transcriptional Coordination in the Model Diatom Phaeodactylum tricornutum. FRONTIERS IN PLANT SCIENCE 2020; 11:590949. [PMID: 33178253 PMCID: PMC7596299 DOI: 10.3389/fpls.2020.590949] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 09/15/2020] [Indexed: 05/04/2023]
Abstract
Transcriptional coordination is a fundamental component of prokaryotic and eukaryotic cell biology, underpinning the cell cycle, physiological transitions, and facilitating holistic responses to environmental stress, but its overall dynamics in eukaryotic algae remain poorly understood. Better understanding of transcriptional partitioning may provide key insights into the primary metabolism pathways of eukaryotic algae, which frequently depend on intricate metabolic associations between the chloroplasts and mitochondria that are not found in plants. Here, we exploit 187 publically available RNAseq datasets generated under varying nitrogen, iron and phosphate growth conditions to understand the co-regulatory principles underpinning transcription in the model diatom Phaeodactylum tricornutum. Using WGCNA (Weighted Gene Correlation Network Analysis), we identify 28 merged modules of co-expressed genes in the P. tricornutum genome, which show high connectivity and correlate well with previous microarray-based surveys of gene co-regulation in this species. We use combined functional, subcellular localization and evolutionary annotations to reveal the fundamental principles underpinning the transcriptional co-regulation of genes implicated in P. tricornutum chloroplast and mitochondrial metabolism, as well as the functions of diverse transcription factors underpinning this co-regulation. The resource is publically available as PhaeoNet, an advanced tool to understand diatom gene co-regulation.
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Affiliation(s)
- Ouardia Ait-Mohamed
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Anna M. G. Novák Vanclová
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Nathalie Joli
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Yue Liang
- Department of Oceanography, Dalhousie University, Halifax, NS, Canada
| | - Xue Zhao
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
- Université de Nantes, CNRS, UFIP, UMR 6286, Nantes, France
| | - Auguste Genovesio
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Leila Tirichine
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
- Université de Nantes, CNRS, UFIP, UMR 6286, Nantes, France
- *Correspondence: Leila Tirichine,
| | - Chris Bowler
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
- Chris Bowler,
| | - Richard G. Dorrell
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
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19
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Erdene-Ochir E, Shin BK, Kwon B, Jung C, Pan CH. Identification and characterisation of the novel endogenous promoter HASP1 and its signal peptide from Phaeodactylum tricornutum. Sci Rep 2019; 9:9941. [PMID: 31289300 PMCID: PMC6617621 DOI: 10.1038/s41598-019-45786-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/10/2019] [Indexed: 12/20/2022] Open
Abstract
Although diatoms have been extensively studied as bioreactors, only a limited number of efficient gene promoters are available. Therefore, the development of new endogenous promoters is important for the heterologous production of a variety of recombinant proteins. Herein, we identified the most abundant secreted protein in Phaeodactylum tricornutum, designated ‘highly abundant secreted protein 1’ (HASP1), and characterised the activities of its promoter and signal peptide using green fluorescent protein (GFP) as a reporter. The HASP1 promoter strongly drove GFP expression during all growth phases of P. tricornutum in culture, in contrast to the commonly used fcpA promoter, which is less active during the stationary phase. The HASP1 signal peptide was also sufficient for facilitating efficient secretion of GFP by P. tricornutum. Our findings suggest that both the promoter and the signal peptide of HASP1 can be utilized as novel tools for the overexpression and secretion of recombinant proteins in P. tricornutum.
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Affiliation(s)
- Erdenedolgor Erdene-Ochir
- Natural Product Informatics Research Center, KIST Gangneung Institute of Natural Products, Gangneung, 25451, Republic of Korea.,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Republic of Korea
| | - Bok-Kyu Shin
- Algaeprona Inc, Gangneung, 25451, Republic of Korea
| | - Byeori Kwon
- Algaeprona Inc, Gangneung, 25451, Republic of Korea
| | - Choonkyun Jung
- Graduate School of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, 25354, Republic of Korea.
| | - Cheol-Ho Pan
- Natural Product Informatics Research Center, KIST Gangneung Institute of Natural Products, Gangneung, 25451, Republic of Korea. .,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Republic of Korea.
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20
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Heal KR, Kellogg NA, Carlson LT, Lionheart RM, Ingalls AE. Metabolic Consequences of Cobalamin Scarcity in the Diatom Thalassiosira pseudonana as Revealed Through Metabolomics. Protist 2019; 170:328-348. [PMID: 31260945 DOI: 10.1016/j.protis.2019.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 05/17/2019] [Accepted: 05/19/2019] [Indexed: 02/07/2023]
Abstract
Diatoms perform an estimated 20% of global photosynthesis, form the base of the marine food web, and sequester carbon into the deep ocean through the biological pump. In some areas of the ocean, diatom growth is limited by the micronutrient cobalamin (vitamin B12), yet the biochemical ramifications of cobalamin limitation are not well understood. In a laboratory setting, we grew the diatom Thalassiosira pseudonana under replete and low cobalamin conditions to elucidate changes in metabolite pools. Using metabolomics, we show that the diatom experienced a metabolic cascade under cobalamin limitation that affected the central methionine cycle, transsulfuration pathway, and composition of osmolyte pools. In T. pseudonana, 5'-methylthioadenosine decreased under low cobalamin conditions, suggesting a disruption in the diatom's polyamine biosynthesis. Furthermore, two acylcarnitines accumulated under low cobalamin, suggesting the limited use of an adenosylcobalamin-dependent enzyme, methylmalonyl CoA mutase. Overall, these changes in metabolite pools yield insight into the metabolic consequences of cobalamin limitation in diatoms and suggest that cobalamin availability may have consequences for microbial interactions that are based on metabolite production by phytoplankton.
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Affiliation(s)
- Katherine R Heal
- School of Oceanography, University of Washington, Seattle, WA 98195, USA
| | - Natalie A Kellogg
- School of Oceanography, University of Washington, Seattle, WA 98195, USA
| | - Laura T Carlson
- School of Oceanography, University of Washington, Seattle, WA 98195, USA
| | - Regina M Lionheart
- School of Oceanography, University of Washington, Seattle, WA 98195, USA
| | - Anitra E Ingalls
- School of Oceanography, University of Washington, Seattle, WA 98195, USA.
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21
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Yang M, Lin X, Liu X, Zhang J, Ge F. Genome Annotation of a Model Diatom Phaeodactylum tricornutum Using an Integrated Proteogenomic Pipeline. MOLECULAR PLANT 2018; 11:1292-1307. [PMID: 30176371 DOI: 10.1016/j.molp.2018.08.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/26/2018] [Accepted: 08/28/2018] [Indexed: 06/08/2023]
Abstract
Diatoms comprise a diverse and ecologically important group of eukaryotic phytoplankton that significantly contributes to marine primary production and global carbon cycling. Phaeodactylum tricornutum is commonly used as a model organism for studying diatom biology. Although its genome was sequenced in 2008, a high-quality genome annotation is still not available for this diatom. Here we report the development of an integrated proteogenomic pipeline and its application for improved annotation of P. tricornutum genome using mass spectrometry (MS)-based proteomics data. Our proteogenomic analysis unambiguously identified approximately 8300 genes and revealed 606 novel proteins, 506 revised genes, 94 splice variants, 58 single amino acid variants, and a holistic view of post-translational modifications in P. tricornutum. We experimentally confirmed a subset of novel events and obtained MS evidence for more than 200 micropeptides in P. tricornutum. These findings expand the genomic landscape of P. tricornutum and provide a rich resource for the study of diatom biology. The proteogenomic pipeline we developed in this study is applicable to any sequenced eukaryote and thus represents a significant contribution to the toolset for eukaryotic proteogenomic analysis. The pipeline and its source code are freely available at https://sourceforge.net/projects/gapeproteogenomic.
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Affiliation(s)
- Mingkun Yang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xiaohuang Lin
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Xin Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Jia Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Feng Ge
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China.
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22
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Ovide C, Kiefer-Meyer MC, Bérard C, Vergne N, Lecroq T, Plasson C, Burel C, Bernard S, Driouich A, Lerouge P, Tournier I, Dauchel H, Bardor M. Comparative in depth RNA sequencing of P. tricornutum's morphotypes reveals specific features of the oval morphotype. Sci Rep 2018; 8:14340. [PMID: 30254372 PMCID: PMC6156597 DOI: 10.1038/s41598-018-32519-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 08/21/2018] [Indexed: 11/09/2022] Open
Abstract
Phaeodactylum tricornutum is the most studied diatom encountered principally in coastal unstable environments. It has been hypothesized that the great adaptability of P. tricornutum is probably due to its pleomorphism. Indeed, P. tricornutum is an atypical diatom since it can display three morphotypes: fusiform, triradiate and oval. Currently, little information is available regarding the physiological significance of this morphogenesis. In this study, we adapted P. tricornutum Pt3 strain to obtain algal culture particularly enriched in one dominant morphotype: fusiform, triradiate or oval. These cultures were used to run high-throughput RNA-Sequencing. The whole mRNA transcriptome of each morphotype was determined. Pairwise comparisons highlighted biological processes and molecular functions which are up- and down-regulated. Finally, intersection analysis allowed us to identify the specific features from the oval morphotype which is of particular interest as it is often described to be more resistant to stresses. This study represent the first transcriptome wide characterization of the three morphotypes from P. tricornutum performed on cultures specifically enriched issued from the same Pt3 strain. This work represents an important step for the understanding of the morphogenesis in P. tricornutum and highlights the particular features of the oval morphotype.
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Affiliation(s)
- Clément Ovide
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | | | - Caroline Bérard
- Normandie Univ, UNIROUEN, LITIS EA 4108, 76000, Rouen, France
| | - Nicolas Vergne
- Normandie Univ, UNIROUEN, LMRS UMR 6085 CNRS, 76000, Rouen, France
| | - Thierry Lecroq
- Normandie Univ, UNIROUEN, LITIS EA 4108, 76000, Rouen, France
| | - Carole Plasson
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | - Carole Burel
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | - Sophie Bernard
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Plate-forme PRIMACEN, 76000, Rouen, France
| | - Azeddine Driouich
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Plate-forme PRIMACEN, 76000, Rouen, France
| | - Patrice Lerouge
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | - Isabelle Tournier
- Normandie Univ, UNIROUEN, Inserm U1079, IRIB Genomic Facility, 76000, Rouen, France
| | - Hélène Dauchel
- Normandie Univ, UNIROUEN, LITIS EA 4108, 76000, Rouen, France.
| | - Muriel Bardor
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France. .,Institut Universitaire de France (IUF), Paris, France.
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23
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Pan Y, Yang J, Gong Y, Li X, Hu H. 3-Hydroxyisobutyryl-CoA hydrolase involved in isoleucine catabolism regulates triacylglycerol accumulation in Phaeodactylum tricornutum. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0409. [PMID: 28717019 DOI: 10.1098/rstb.2016.0409] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2017] [Indexed: 11/12/2022] Open
Abstract
Since methylmalonyl-CoA epimerase appears to be absent in the majority of photosynthetic organisms, including diatoms, (S)-methylmalonyl-CoA, the intermediate of isoleucine (Ile) catabolism, cannot be metabolized to (R)-methylmalonyl-CoA then to succinyl-CoA. In this study, propionyl-CoA carboxylase (PCC) RNAi silenced strains and 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) overexpression strains were constructed to elucidate the Ile degradation pathway and its influence on lipid accumulation in Phaeodactylum tricornutum based on growth, neutral lipid content and metabolite profile analysis. Knockdown of PCC disturbed the metabolism of Ile through propionyl-CoA to methylmalonyl-CoA, as illustrated by much higher Ile content at day 6. However, Ile decreased to comparable levels to the wild-type at day 10. PCC silencing redirected propionyl-CoA to acetyl-CoA via a modified β-oxidation pathway, and transcript levels for some branched-chain amino acid (BCAA) degradation-related genes, especially HIBCH, significantly upregulated in the PCC mutant, which enhanced the BCAA degradations and thus resulted in higher triacylglycerol (TAG) content. Overexpression of HIBCH accelerates Ile degradation and results in a lowered Ile content in the overexpression strains, thus enhancing carbon skeletons to the tricarboxylic acid cycle and giving rise to increasing TAG accumulation. Our study provides a good strategy to obtain high-lipid-yield transgenic diatoms by modifying the propionyl-CoA metabolism.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.
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Affiliation(s)
- Yufang Pan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Juan Yang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yangmin Gong
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, People's Republic of China
| | - Xiaolong Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Hanhua Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
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24
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Rastogi A, Maheswari U, Dorrell RG, Vieira FRJ, Maumus F, Kustka A, McCarthy J, Allen AE, Kersey P, Bowler C, Tirichine L. Integrative analysis of large scale transcriptome data draws a comprehensive landscape of Phaeodactylum tricornutum genome and evolutionary origin of diatoms. Sci Rep 2018; 8:4834. [PMID: 29556065 PMCID: PMC5859163 DOI: 10.1038/s41598-018-23106-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 03/02/2018] [Indexed: 11/13/2022] Open
Abstract
Diatoms are one of the most successful and ecologically important groups of eukaryotic phytoplankton in the modern ocean. Deciphering their genomes is a key step towards better understanding of their biological innovations, evolutionary origins, and ecological underpinnings. Here, we have used 90 RNA-Seq datasets from different growth conditions combined with published expressed sequence tags and protein sequences from multiple taxa to explore the genome of the model diatom Phaeodactylum tricornutum, and introduce 1,489 novel genes. The new annotation additionally permitted the discovery of extensive alternative splicing in diatoms, including intron retention and exon skipping, which increase the diversity of transcripts generated in changing environments. In addition, we have used up-to-date reference sequence libraries to dissect the taxonomic origins of diatom genes. We show that the P. tricornutum genome is enriched in lineage-specific genes, with up to 47% of the gene models present only possessing orthologues in other stramenopile groups. Finally, we have performed a comprehensive de novo annotation of repetitive elements showing novel classes of transposable elements such as SINE, MITE and TRIM/LARD. This work provides a solid foundation for future studies of diatom gene function, evolution and ecology.
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Affiliation(s)
- Achal Rastogi
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, 75005, Paris, France
| | - Uma Maheswari
- EMBL-EBI, Wellcome Trust Genome Campus, Cambridge, CB10 1 SD, United Kingdom
| | - Richard G Dorrell
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, 75005, Paris, France
| | - Fabio Rocha Jimenez Vieira
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, 75005, Paris, France
| | - Florian Maumus
- URGI, INRA, Université Paris-Saclay, Versailles, 78026, France
| | - Adam Kustka
- Earth and Environmental Sciences, Rutgers University, 101 Warren Street, 07102, Newark, New Jersey, USA
| | - James McCarthy
- J. Craig Venter Institute, 10355 Science Center Drive, 92121, San Diego, California, USA
| | - Andy E Allen
- J. Craig Venter Institute, 10355 Science Center Drive, 92121, San Diego, California, USA
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Paul Kersey
- EMBL-EBI, Wellcome Trust Genome Campus, Cambridge, CB10 1 SD, United Kingdom
| | - Chris Bowler
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, 75005, Paris, France.
| | - Leila Tirichine
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, 75005, Paris, France.
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25
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Gong W, Paerl H, Marchetti A. Eukaryotic phytoplankton community spatiotemporal dynamics as identified through gene expression within a eutrophic estuary. Environ Microbiol 2018; 20:1095-1111. [PMID: 29349913 DOI: 10.1111/1462-2920.14049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 12/18/2017] [Accepted: 01/12/2018] [Indexed: 01/13/2023]
Abstract
Over the span of a year, we investigated the interactions between biotic and abiotic factors within the eutrophic Neuse River Estuary (NRE). Through metatranscriptomic sequencing in combination with water quality measurements, we show that there are different metabolic strategies deployed along the NRE. In the upper estuary, taxonomically resolved phytoplankton groups express more transcripts of genes for synthesis of cellular components and carbon metabolism whereas in the lower estuary, transcripts allocated to nutrient metabolism and transport were more highly expressed. Metabolisms for polysaccharide synthesis and transportation were elevated in the lower estuary and could be reflective of unbalanced growth and/or interactions with their surrounding microbial consortia. Our results indicate phytoplankton have high metabolic activity, suggestive of increased growth rates in the upper estuary and display patterns reflective of nutrient limitation in the lower estuary. Among all the environmental parameters varying along the NRE, nitrogen availability is found to be the main driving factor for the observed spatial divergence.
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Affiliation(s)
- Weida Gong
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Murray Hall, 123 South Rd, Chapel Hill, NC 27514, USA
| | - Hans Paerl
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, 3431 Arendell Street, Morehead City, NC 28557, USA
| | - Adrian Marchetti
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Murray Hall, 123 South Rd, Chapel Hill, NC 27514, USA
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26
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Jian J, Zeng D, Wei W, Lin H, Li P, Liu W. The Combination of RNA and Protein Profiling Reveals the Response to Nitrogen Depletion in Thalassiosira pseudonana. Sci Rep 2017; 7:8989. [PMID: 28827639 PMCID: PMC5566445 DOI: 10.1038/s41598-017-09546-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 07/24/2017] [Indexed: 12/21/2022] Open
Abstract
Nitrogen (N) is essential for the growth of algae, and its concentration varies greatly in the ocean, which has been regarded as a limitation for phytoplankton growth. Despite its great importance, most of the existing studies on the mechanisms underlying the effects of N on diatoms have focused on physiology, biochemistry and a few target genes and have rarely involved whole genomic analyses. Therefore, in this study, we integrated physiological data with RNA and protein profiling data to reveal the response strategy of Thalassiosira pseudonana under N-depleted conditions. Physiological measurements indicated that the cell growth capacity and chlorophyll content of the cells decreased, as did the expression of photosynthesis- and chlorophyll biosynthesis-related genes or proteins. The RNA-Seq profile results showed that T. pseudonana responded to N deprivation through increases in glycolysis, the TCA cycle and N metabolism as well as down-regulation in the Calvin cycle, gluconeogenesis, pentose phosphate, oxidative phosphorylation and lipid synthesis. These results provide a basic understanding for further research addressing how N affects phytoplankton in terms of genomics.
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Affiliation(s)
- Jianbo Jian
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China
| | - Dezhi Zeng
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China
| | - Wei Wei
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China
| | - Hongmin Lin
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China
| | - Ping Li
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China.
| | - Wenhua Liu
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China.
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27
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Thompson SEM, Coates JC. Surface sensing and stress-signalling in Ulva and fouling diatoms - potential targets for antifouling: a review. BIOFOULING 2017; 33:410-432. [PMID: 28508711 DOI: 10.1080/08927014.2017.1319473] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 04/11/2017] [Indexed: 06/07/2023]
Abstract
Understanding the underlying signalling pathways that enable fouling algae to sense and respond to surfaces is essential in the design of environmentally friendly coatings. Both the green alga Ulva and diverse diatoms are important ecologically and economically as they are persistent biofoulers. Ulva spores exhibit rapid secretion, allowing them to adhere quickly and permanently to a ship, whilst diatoms secrete an abundance of extracellular polymeric substances (EPS), which are highly adaptable to different environmental conditions. There is evidence, now supported by molecular data, for complex calcium and nitric oxide (NO) signalling pathways in both Ulva and diatoms being involved in surface sensing and/or adhesion. Moreover, adaptation to stress has profound effects on the biofouling capability of both types of organism. Targets for future antifouling coatings based on surface sensing are discussed, with an emphasis on pursuing NO-releasing coatings as a potentially universal antifouling strategy.
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Affiliation(s)
| | - Juliet C Coates
- a School of Biosciences , University of Birmingham , Birmingham , UK
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28
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Tirichine L, Rastogi A, Bowler C. Recent progress in diatom genomics and epigenomics. CURRENT OPINION IN PLANT BIOLOGY 2017; 36:46-55. [PMID: 28226268 DOI: 10.1016/j.pbi.2017.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 01/31/2017] [Accepted: 02/02/2017] [Indexed: 06/06/2023]
Abstract
Diatoms are one of the most diverse and successful groups of phytoplankton at the base of the food chain, sustaining life in the ocean and performing vital biogeochemical functions. The last fifteen years have witnessed the comprehensive analysis of several diatom genomes, revealing that they bear traces of their endosymbiotic origins from algal and heterotrophic ancestors, as well as significant gene transfer from bacteria. Their chimeric genomes are further regulated by a range of chromatin-based processes that are characteristic of both plant and animal genomes. We discuss the conservation of gene regulatory mechanisms in diatoms and propose that epigenetic processes may have a significant role in mediating responses to a highly dynamic and unpredictable environment in these organisms.
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Affiliation(s)
- Leila Tirichine
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France.
| | - Achal Rastogi
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France
| | - Chris Bowler
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France
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29
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Gong W, Browne J, Hall N, Schruth D, Paerl H, Marchetti A. Molecular insights into a dinoflagellate bloom. ISME JOURNAL 2016; 11:439-452. [PMID: 27935592 DOI: 10.1038/ismej.2016.129] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 08/07/2016] [Accepted: 08/15/2016] [Indexed: 01/10/2023]
Abstract
In coastal waters worldwide, an increase in frequency and intensity of algal blooms has been attributed to eutrophication, with further increases predicted because of climate change. Yet, the cellular-level changes that occur in blooming algae remain largely unknown. Comparative metatranscriptomics was used to investigate the underlying molecular mechanisms associated with a dinoflagellate bloom in a eutrophied estuary. Here we show that under bloom conditions, there is increased expression of metabolic pathways indicative of rapidly growing cells, including energy production, carbon metabolism, transporters and synthesis of cellular membrane components. In addition, there is a prominence of highly expressed genes involved in the synthesis of membrane-associated molecules, including those for the production of glycosaminoglycans (GAGs), which may serve roles in nutrient acquisition and/or cell surface adhesion. Biotin and thiamine synthesis genes also increased expression along with several cobalamin biosynthesis-associated genes, suggesting processing of B12 intermediates by dinoflagellates. The patterns in gene expression observed are consistent with bloom-forming dinoflagellates eliciting a cellular response to elevated nutrient demands and to promote interactions with their surrounding bacterial consortia, possibly in an effort to cultivate for enhancement of vitamin and nutrient exchanges and/or direct consumption. Our findings provide potential molecular targets for bloom characterization and management efforts.
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Affiliation(s)
- Weida Gong
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Jamie Browne
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Nathan Hall
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC USA
| | - David Schruth
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Hans Paerl
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC USA
| | - Adrian Marchetti
- Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
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30
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Longworth J, Wu D, Huete-Ortega M, Wright PC, Vaidyanathan S. Proteome response of Phaeodactylum tricornutum, during lipid accumulation induced by nitrogen depletion. ALGAL RES 2016; 18:213-224. [PMID: 27812494 PMCID: PMC5070409 DOI: 10.1016/j.algal.2016.06.015] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 05/08/2016] [Accepted: 06/14/2016] [Indexed: 11/26/2022]
Abstract
Nitrogen stress is a common strategy employed to stimulate lipid accumulation in microalgae, a biofuel feedstock of topical interest. Although widely investigated, the underlying mechanism of this strategy is still poorly understood. We examined the proteome response of lipid accumulation in the model diatom, Phaeodactylum tricornutum (CCAP 1055/1), at an earlier stage of exposure to selective nitrogen exclusion than previously investigated, and at a time point when changes would reflect lipid accumulation more than carbohydrate accumulation. In total 1043 proteins were confidently identified (≥ 2 unique peptides) with 645 significant (p < 0.05) changes observed, in the LC-MS/MS based iTRAQ investigation. Analysis of significant changes in KEGG pathways and individual proteins showed that under nitrogen starvation P. tricornutum reorganizes its proteome in favour of nitrogen scavenging and reduced lipid degradation whilst rearranging the central energy metabolism that deprioritizes photosynthetic pathways. By doing this, this species appears to increase nitrogen availability inside the cell and limit its use to the pathways where it is needed most. Compared to previously published proteomic analysis of nitrogen starvation in Chlamydomonas reinhardtii, central energy metabolism and photosynthesis appear to be affected more in the diatom, whilst the green algae appears to invest its energy in reorganizing respiration and the cellular organization pathways.
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31
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Chu L, Ewe D, Río Bártulos C, Kroth PG, Gruber A. Rapid induction of GFP expression by the nitrate reductase promoter in the diatom Phaeodactylum tricornutum. PeerJ 2016; 4:e2344. [PMID: 27635322 PMCID: PMC5012323 DOI: 10.7717/peerj.2344] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 07/19/2016] [Indexed: 02/06/2023] Open
Abstract
An essential prerequisite for a controlled transgene expression is the choice of a suitable promoter. In the model diatom Phaeodactylum tricornutum, the most commonly used promoters for trans-gene expression are the light dependent lhcf1 promoters (derived from two endogenous genes encoding fucoxanthin chlorophyll a/c binding proteins) and the nitrate dependent nr promoter (derived from the endogenous nitrate reductase gene). In this study, we investigated the time dependent expression of the green fluorescent protein (GFP) reporter under control of the nitrate reductase promoter in independently genetically transformed P. tricornutum cell lines following induction of expression by change of the nitrogen source in the medium via flow cytometry, microscopy and western blotting. In all investigated cell lines, GFP fluorescence started to increase 1 h after change of the medium, the fastest increase rates were observed between 2 and 3 h. Fluorescence continued to increase slightly for up to 7 h even after transfer of the cells to ammonium medium. The subsequent decrease of GFP fluorescence was much slower than the increase, probably due to the stability of GFP. The investigation of several cell lines transformed with nr based constructs revealed that, also in the absence of nitrate, the promoter may show residual activity. Furthermore, we observed a strong variation of gene expression between independent cell lines, emphasising the importance of a thorough characterisation of genetically modified cell lines and their individual expression patterns.
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Affiliation(s)
- Lili Chu
- Fachbereich Biologie, Universität Konstanz , Konstanz , Germany
| | - Daniela Ewe
- Fachbereich Biologie, Universität Konstanz, Konstanz, Germany; Current affiliation: Centre Algatech, Institute of Microbiology, The Czech Academy of Science, Třeboň, Czech Republic
| | | | - Peter G Kroth
- Fachbereich Biologie, Universität Konstanz , Konstanz , Germany
| | - Ansgar Gruber
- Fachbereich Biologie, Universität Konstanz , Konstanz , Germany
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32
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Hunsperger HM, Ford CJ, Miller JS, Cattolico RA. Differential Regulation of Duplicate Light-Dependent Protochlorophyllide Oxidoreductases in the Diatom Phaeodactylum tricornutum. PLoS One 2016; 11:e0158614. [PMID: 27367227 PMCID: PMC4930169 DOI: 10.1371/journal.pone.0158614] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/17/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Diatoms (Bacilliariophyceae) encode two light-dependent protochlorophyllide oxidoreductases (POR1 and POR2) that catalyze the penultimate step of chlorophyll biosynthesis in the light. Algae live in dynamic environments whose changing light levels induce photoacclimative metabolic shifts, including altered cellular chlorophyll levels. We hypothesized that the two POR proteins may be differentially adaptive under varying light conditions. Using the diatom Phaeodactylum tricornutum as a test system, differences in POR protein abundance and por gene expression were examined when this organism was grown on an alternating light:dark cycles at different irradiances; exposed to continuous light; and challenged by a significant decrease in light availability. RESULTS For cultures maintained on a 12h light: 12h dark photoperiod at 200μE m-2 s-1 (200L/D), both por genes were up-regulated during the light and down-regulated in the dark, though por1 transcript abundance rose and fell earlier than that of por2. Little concordance occurred between por1 mRNA and POR1 protein abundance. In contrast, por2 mRNA and POR2 protein abundances followed similar diurnal patterns. When 200L/D P. tricornutum cultures were transferred to continuous light (200L/L), the diurnal regulatory pattern of por1 mRNA abundance but not of por2 was disrupted, and POR1 but not POR2 protein abundance dropped steeply. Under 1200μE m-2 s-1 (1200L/D), both por1 mRNA and POR1 protein abundance displayed diurnal oscillations. A compromised diel por2 mRNA response under 1200L/D did not impact the oscillation in POR2 abundance. When cells grown at 1200L/D were then shifted to 50μE m-2 s-1 (50L/D), por1 and por2 mRNA levels decreased swiftly but briefly upon light reduction. Thereafter, POR1 but not POR2 protein levels rose significantly in response to this light stepdown. CONCLUSION Given the sensitivity of diatom por1/POR1 to real-time light cues and adherence of por2/POR2 regulation to the diurnal cycle, we suggest that POR1 supports photoacclimation, whereas POR2 is the workhorse for daily chlorophyll synthesis.
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Affiliation(s)
- Heather M. Hunsperger
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Christopher J. Ford
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - James S. Miller
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Rose Ann Cattolico
- Department of Biology, University of Washington, Seattle, Washington, United States of America
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33
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Bussard A, Corre E, Hubas C, Duvernois-Berthet E, Le Corguillé G, Jourdren L, Coulpier F, Claquin P, Lopez PJ. Physiological adjustments and transcriptome reprogramming are involved in the acclimation to salinity gradients in diatoms. Environ Microbiol 2016; 19:909-925. [DOI: 10.1111/1462-2920.13398] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Adrien Bussard
- UMR Biologie des Organismes et des Ecosystèmes Aquatiques, CNRS 7208-MNHN-UPMC-IRD 207-UCN-UA; 43 rue Cuvier Paris 75005 France
| | - Erwan Corre
- CNRS, UPMC, FR2424, ABiMS, Station Biologique; Roscoff 29680 France
| | - Cédric Hubas
- UMR Biologie des Organismes et des Ecosystèmes Aquatiques, CNRS 7208-MNHN-UPMC-IRD 207-UCN-UA; 43 rue Cuvier Paris 75005 France
| | | | | | - Laurent Jourdren
- Ecole Normale Supérieure, PSL Research University, CNRS, Inserm, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Plateforme Génomique; Paris 75005 France
| | - Fanny Coulpier
- Ecole Normale Supérieure, PSL Research University, CNRS, Inserm, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Plateforme Génomique; Paris 75005 France
| | - Pascal Claquin
- UMR Biologie des Organismes et des Ecosystèmes Aquatiques, CNRS 7208-MNHN-UPMC-IRD 207-UCN-UA, Esplanade de la paix; Caen 14032 France
| | - Pascal Jean Lopez
- UMR Biologie des Organismes et des Ecosystèmes Aquatiques, CNRS 7208-MNHN-UPMC-IRD 207-UCN-UA; 43 rue Cuvier Paris 75005 France
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Buhmann MT, Schulze B, Förderer A, Schleheck D, Kroth PG. Bacteria may induce the secretion of mucin-like proteins by the diatom Phaeodactylum tricornutum. JOURNAL OF PHYCOLOGY 2016; 52:463-74. [PMID: 26993172 DOI: 10.1111/jpy.12409] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/19/2016] [Indexed: 05/10/2023]
Abstract
Benthic diatoms live in photoautotrophic/heterotrophic biofilm communities embedded in a matrix of secreted extracellular polymeric substances. Closely associated bacteria influence their growth, aggregation, and secretion of exopolymers. We have studied a diatom/bacteria model community, in which a marine Roseobacter strain is able to grow with secreted diatom exopolymers as a sole source of carbon. The strain influences the aggregation of Phaeodactylum tricornutum by inducing a morphotypic transition from planktonic, fusiform cells to benthic, oval cells. Analysis of the extracellular soluble proteome of P. tricornutum in the presence and absence of bacteria revealed constitutively expressed newly identified proteins with mucin-like domains that appear to be typical for extracellular diatom proteins. In contrast to mucins, the proline-, serine-, threonine-rich (PST) domains in these proteins were also found in combination with protease-, glucosidase- and leucine-rich repeat-domains. Bioinformatic functional predictions indicate that several of these newly identified diatom-specific proteins may be involved in algal defense, intercellular signaling, and aggregation.
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Affiliation(s)
| | - Birgit Schulze
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany
| | | | - David Schleheck
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany
| | - Peter G Kroth
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany
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Cooper JT, Sinclair GA, Wawrik B. Transcriptome Analysis of Scrippsiella trochoidea CCMP 3099 Reveals Physiological Changes Related to Nitrate Depletion. Front Microbiol 2016; 7:639. [PMID: 27242681 PMCID: PMC4860509 DOI: 10.3389/fmicb.2016.00639] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/18/2016] [Indexed: 01/25/2023] Open
Abstract
Dinoflagellates are a major component of marine phytoplankton and many species are recognized for their ability to produce harmful algal blooms (HABs). Scrippsiella trochoidea is a non-toxic, marine dinoflagellate that can be found in both cold and tropic waters where it is known to produce “red tide” events. Little is known about the genomic makeup of S. trochoidea and a transcriptome study was conducted to shed light on the biochemical and physiological adaptations related to nutrient depletion. Cultures were grown under N and P limiting conditions and transcriptomes were generated via RNAseq technology. De novo assembly reconstructed 107,415 putative transcripts of which only 41% could be annotated. No significant transcriptomic response was observed in response to initial P depletion, however, a strong transcriptional response to N depletion was detected. Among the down-regulated pathways were those for glutamine/glutamate metabolism as well as urea and nitrate/nitrite transporters. Transcripts for ammonia transporters displayed both up- and down-regulation, perhaps related to a shift to higher affinity transporters. Genes for the utilization of DON compounds were up-regulated. These included transcripts for amino acids transporters, polyamine oxidase, and extracellular proteinase and peptidases. N depletion also triggered down regulation of transcripts related to the production of Photosystems I & II and related proteins. These data are consistent with a metabolic strategy that conserves N while maximizing sustained metabolism by emphasizing the relative contribution of organic N sources. Surprisingly, the transcriptome also contained transcripts potentially related to secondary metabolite production, including a homolog to the Short Isoform Saxitoxin gene (sxtA) from Alexandrium fundyense, which was significantly up-regulated under N-depletion. A total of 113 unique hits to Sxt genes, covering 17 of the 34 genes found in C. raciborskii were detected, indicating that S. trochoidea has previously unrecognized potential for the production of secondary metabolites with potential toxicity.
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Affiliation(s)
- Joshua T Cooper
- Department of Microbiology and Plant Biology, University of Oklahoma Norman, OK, USA
| | - Geoffrey A Sinclair
- Department of Marine, Earth and Atmospheric Sciences, North Carolina State University Raleigh, NC, USA
| | - Boris Wawrik
- Department of Microbiology and Plant Biology, University of Oklahoma Norman, OK, USA
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36
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Smith SR, Glé C, Abbriano RM, Traller JC, Davis A, Trentacoste E, Vernet M, Allen AE, Hildebrand M. Transcript level coordination of carbon pathways during silicon starvation-induced lipid accumulation in the diatom Thalassiosira pseudonana. THE NEW PHYTOLOGIST 2016; 210:890-904. [PMID: 26844818 PMCID: PMC5067629 DOI: 10.1111/nph.13843] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 12/03/2015] [Indexed: 05/06/2023]
Abstract
Diatoms are one of the most productive and successful photosynthetic taxa on Earth and possess attributes such as rapid growth rates and production of lipids, making them candidate sources of renewable fuels. Despite their significance, few details of the mechanisms used to regulate growth and carbon metabolism are currently known, hindering metabolic engineering approaches to enhance productivity. To characterize the transcript level component of metabolic regulation, genome-wide changes in transcript abundance were documented in the model diatom Thalassiosira pseudonana on a time-course of silicon starvation. Growth, cell cycle progression, chloroplast replication, fatty acid composition, pigmentation, and photosynthetic parameters were characterized alongside lipid accumulation. Extensive coordination of large suites of genes was observed, highlighting the existence of clusters of coregulated genes as a key feature of global gene regulation in T. pseudonana. The identity of key enzymes for carbon metabolic pathway inputs (photosynthesis) and outputs (growth and storage) reveals these clusters are organized to synchronize these processes. Coordinated transcript level responses to silicon starvation are probably driven by signals linked to cell cycle progression and shifts in photophysiology. A mechanistic understanding of how this is accomplished will aid efforts to engineer metabolism for development of algal-derived biofuels.
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Affiliation(s)
- Sarah R. Smith
- Scripps Institution of OceanographyUC San Diego9500 Gilman DriveLa JollaCA92093USA
- J. Craig Venter Institute4120 Capricorn LaneLa JollaCA92037USA
| | - Corine Glé
- Scripps Institution of OceanographyUC San Diego9500 Gilman DriveLa JollaCA92093USA
| | - Raffaela M. Abbriano
- Scripps Institution of OceanographyUC San Diego9500 Gilman DriveLa JollaCA92093USA
| | - Jesse C. Traller
- Scripps Institution of OceanographyUC San Diego9500 Gilman DriveLa JollaCA92093USA
| | - Aubrey Davis
- Scripps Institution of OceanographyUC San Diego9500 Gilman DriveLa JollaCA92093USA
| | - Emily Trentacoste
- Scripps Institution of OceanographyUC San Diego9500 Gilman DriveLa JollaCA92093USA
| | - Maria Vernet
- Scripps Institution of OceanographyUC San Diego9500 Gilman DriveLa JollaCA92093USA
| | - Andrew E. Allen
- Scripps Institution of OceanographyUC San Diego9500 Gilman DriveLa JollaCA92093USA
- J. Craig Venter Institute4120 Capricorn LaneLa JollaCA92037USA
| | - Mark Hildebrand
- Scripps Institution of OceanographyUC San Diego9500 Gilman DriveLa JollaCA92093USA
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37
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Yang J, Pan Y, Bowler C, Zhang L, Hu H. Knockdown of phosphoenolpyruvate carboxykinase increases carbon flux to lipid synthesis in Phaeodactylum tricornutum. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.02.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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38
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Shemi A, Ben-Dor S, Vardi A. Elucidating the composition and conservation of the autophagy pathway in photosynthetic eukaryotes. Autophagy 2016; 11:701-15. [PMID: 25915714 DOI: 10.1080/15548627.2015.1034407] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Aquatic photosynthetic eukaryotes represent highly diverse groups (green, red, and chromalveolate algae) derived from multiple endosymbiosis events, covering a wide spectrum of the tree of life. They are responsible for about 50% of the global photosynthesis and serve as the foundation for oceanic and fresh water food webs. Although the ecophysiology and molecular ecology of some algal species are extensively studied, some basic aspects of algal cell biology are still underexplored. The recent wealth of genomic resources from algae has opened new frontiers to decipher the role of cell signaling pathways and their function in an ecological and biotechnological context. Here, we took a bioinformatic approach to explore the distribution and conservation of TOR and autophagy-related (ATG) proteins (Atg in yeast) in diverse algal groups. Our genomic analysis demonstrates conservation of TOR and ATG proteins in green algae. In contrast, in all 5 available red algal genomes, we could not detect the sequences that encode for any of the 17 core ATG proteins examined, albeit TOR and its interacting proteins are conserved. This intriguing data suggests that the autophagy pathway is not conserved in red algae as it is in the entire eukaryote domain. In contrast, chromalveolates, despite being derived from the red-plastid lineage, retain and express ATG genes, which raises a fundamental question regarding the acquisition of ATG genes during algal evolution. Among chromalveolates, Emiliania huxleyi (Haptophyta), a bloom-forming coccolithophore, possesses the most complete set of ATG genes, and may serve as a model organism to study autophagy in marine protists with great ecological significance.
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Key Words
- ATG, autophagy related
- ATG8
- ATG9
- DUF, domain of unknown function
- EST, expressed sequence tag
- EhV, Emiliania huxleyi virus
- GABARAP, GABA(A) receptor-associated protein
- PtdIns3K, phosphatidylinositol 3-kinase
- RPTOR, regulatory associated protein of MTOR, complex 1
- TOR, target of rapamycin
- TORC, target of rapamycin complex
- Ubl, ubiquitin-like
- Vps, vacuolar protein sorting
- algae
- autophagy
- blooms
- chromalveolata
- phylogenetics
- phytoplankton
- rhodophyta
- stress
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Affiliation(s)
- Adva Shemi
- a Department of Plant Sciences ; Weizmann Institute of Science ; Rehovot , Israel
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39
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Development of a new constitutive expression system for the transformation of the diatom Phaeodactylum tricornutum. ALGAL RES 2015. [DOI: 10.1016/j.algal.2015.05.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Fabris M, Matthijs M, Carbonelle S, Moses T, Pollier J, Dasseville R, Baart GJE, Vyverman W, Goossens A. Tracking the sterol biosynthesis pathway of the diatom Phaeodactylum tricornutum. THE NEW PHYTOLOGIST 2014; 204:521-535. [PMID: 24996048 DOI: 10.1111/nph.12917] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 06/02/2014] [Indexed: 05/03/2023]
Abstract
Diatoms are unicellular photosynthetic microalgae that play a major role in global primary production and aquatic biogeochemical cycling. Endosymbiotic events and recurrent gene transfers uniquely shaped the genome of diatoms, which contains features from several domains of life. The biosynthesis pathways of sterols, essential compounds in all eukaryotic cells, and many of the enzymes involved are evolutionarily conserved in eukaryotes. Although well characterized in most eukaryotes, the pathway leading to sterol biosynthesis in diatoms has remained hitherto unidentified. Through the DiatomCyc database we reconstructed the mevalonate and sterol biosynthetic pathways of the model diatom Phaeodactylum tricornutum in silico. We experimentally verified the predicted pathways using enzyme inhibitor, gene silencing and heterologous gene expression approaches. Our analysis revealed a peculiar, chimeric organization of the diatom sterol biosynthesis pathway, which possesses features of both plant and fungal pathways. Strikingly, it lacks a conventional squalene epoxidase and utilizes an extended oxidosqualene cyclase and a multifunctional isopentenyl diphosphate isomerase/squalene synthase enzyme. The reconstruction of the P. tricornutum sterol pathway underscores the metabolic plasticity of diatoms and offers important insights for the engineering of diatoms for sustainable production of biofuels and high-value chemicals.
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Affiliation(s)
- Michele Fabris
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052, Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Gent, Belgium
- Department of Biology, Laboratory of Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281 (S8), B-9000, Gent, Belgium
| | - Michiel Matthijs
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052, Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Gent, Belgium
- Department of Biology, Laboratory of Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281 (S8), B-9000, Gent, Belgium
| | - Sophie Carbonelle
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052, Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Gent, Belgium
| | - Tessa Moses
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052, Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Gent, Belgium
| | - Jacob Pollier
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052, Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Gent, Belgium
| | - Renaat Dasseville
- Department of Biology, Laboratory of Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281 (S8), B-9000, Gent, Belgium
| | - Gino J E Baart
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052, Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Gent, Belgium
- Department of Biology, Laboratory of Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281 (S8), B-9000, Gent, Belgium
| | - Wim Vyverman
- Department of Biology, Laboratory of Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281 (S8), B-9000, Gent, Belgium
| | - Alain Goossens
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052, Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Gent, Belgium
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41
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Willis A, Eason-Hubbard M, Hodson O, Maheswari U, Bowler C, Wetherbee R. Adhesion molecules from the diatom Phaeodactylum tricornutum (Bacillariophyceae): genomic identification by amino-acid profiling and in vivo analysis. JOURNAL OF PHYCOLOGY 2014; 50:837-849. [PMID: 26988639 DOI: 10.1111/jpy.12214] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 05/22/2014] [Indexed: 06/05/2023]
Abstract
Cell adhesion molecules (CAMs) are important in prokaryotes and eukaryotes for cell-cell and cell-substratum interactions. The characteristics of adhesive proteins in the model diatom Phaeodactylum tricornutum were investigated by bioinformatic analysis and in vivo characterization. Bioinformatic analysis of the protein coding potential of the P. tricornutum genome used an amino-acid profile that we developed as a new system to identify uncharacterized or novel CAMs. Putative diatom CAMs were identified and seven were characterized in vivo, by generation of transgenic diatom lines overexpressing genes encoding C-terminal yellow fluorescent protein (YFP) fusion proteins. Three of these selected genes encode proteins with weak similarity to characterized proteins, a c-type lectin and two fasciclins, whereas the others are novel. The resultant cell lines were investigated for alterations in their adhesive ability. Whole cell-substratum adhesion strength was measured in a fully turbulent flow chamber, while atomic force microscopy was used to quantify the relative frequency of adhesion, as well as the length and strength of single molecules in the secreted mucilage. Finally, quartz crystal microbalance analysis characterized the visco-elastic properties and interaction of the mucilage-substratum interface. These combined studies revealed a range of phenotypes affecting adhesion, and led to the identification of candidate proteins involved in diatom adhesion. In summary, our study has for the first time combined bioinformatics and molecular physiological studies to provide new insights into diatom adhesive molecules.
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Affiliation(s)
- Anusuya Willis
- School of Botany, The University of Melbourne, Parkville, 3010, Victoria, Australia
- Environmental and Evolutionary Genomics Section, CNRS UMR8197 INSERM U1024, Institut de Biologie de l'Ecole Normale Supérieure, 46 rue d'Ulm 75230, Paris Cedex 05, France
| | - Maeve Eason-Hubbard
- School of Botany, The University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Oliver Hodson
- School of Botany, The University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Uma Maheswari
- Environmental and Evolutionary Genomics Section, CNRS UMR8197 INSERM U1024, Institut de Biologie de l'Ecole Normale Supérieure, 46 rue d'Ulm 75230, Paris Cedex 05, France
| | - Chris Bowler
- Environmental and Evolutionary Genomics Section, CNRS UMR8197 INSERM U1024, Institut de Biologie de l'Ecole Normale Supérieure, 46 rue d'Ulm 75230, Paris Cedex 05, France
| | - Richard Wetherbee
- School of Botany, The University of Melbourne, Parkville, 3010, Victoria, Australia
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42
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Tirichine L, Lin X, Thomas Y, Lombard B, Loew D, Bowler C. Re-print of "Histone extraction protocol from the two model diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana". Mar Genomics 2014; 16:67-71. [PMID: 24859489 DOI: 10.1016/j.margen.2014.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/27/2013] [Accepted: 11/21/2013] [Indexed: 11/25/2022]
Abstract
Post-translational modifications of histones affect many biological processes by influencing higher order chromatin structure that affects gene and genome regulation. It is therefore important to develop methods for extracting histones while maintaining their native post-translational modifications. While histone extraction protocols have been developed in multicellular and single celled organisms such as yeast and Arabidopsis, they are inefficient in diatoms that have a silica cell wall that is likely to hinder histone extraction. We report in this work a rapid and reliable method for extraction of large amounts of high quality histones from the two model diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana. The protocol is an important enabling step permitting downstream applications such as western blotting and mass spectrometry.
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Affiliation(s)
- Leïla Tirichine
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197 INSERM U1024, 46 rue d'Ulm 75005 Paris, France.
| | - Xin Lin
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197 INSERM U1024, 46 rue d'Ulm 75005 Paris, France
| | - Yann Thomas
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197 INSERM U1024, 46 rue d'Ulm 75005 Paris, France
| | - Bérangère Lombard
- Institut Curie, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 26 rue d'Ulm 75248 Cedex 05 Paris, France
| | - Damarys Loew
- Institut Curie, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 26 rue d'Ulm 75248 Cedex 05 Paris, France
| | - Chris Bowler
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197 INSERM U1024, 46 rue d'Ulm 75005 Paris, France
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43
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Chen Z, Yang MK, Li CY, Wang Y, Zhang J, Wang DB, Zhang XE, Ge F. Phosphoproteomic analysis provides novel insights into stress responses in Phaeodactylum tricornutum, a model diatom. J Proteome Res 2014; 13:2511-23. [PMID: 24712722 DOI: 10.1021/pr401290u] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein phosphorylation on serine, threonine, and tyrosine (Ser/Thr/Tyr) is well established as a key regulatory posttranslational modification used in signal transduction to control cell growth, proliferation, and stress responses. However, little is known about its extent and function in diatoms. Phaeodactylum tricornutum is a unicellular marine diatom that has been used as a model organism for research on diatom molecular biology. Although more than 1000 protein kinases and phosphatases with specificity for Ser/Thr/Tyr residues have been predicted in P. tricornutum, no phosphorylation event has so far been revealed by classical biochemical approaches. Here, we performed a global phosphoproteomic analysis combining protein/peptide fractionation, TiO(2) enrichment, and LC-MS/MS analyses. In total, we identified 264 unique phosphopeptides, including 434 in vivo phosphorylated sites on 245 phosphoproteins. The phosphorylated proteins were implicated in the regulation of diverse biological processes, including signaling, metabolic pathways, and stress responses. Six identified phosphoproteins were further validated by Western blotting using phospho-specific antibodies. The functions of these proteins are discussed in the context of signal transduction networks in P. tricornutum. Our results advance the current understanding of diatom biology and will be useful for elucidating the phosphor-relay signaling networks in this model diatom.
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Affiliation(s)
- Zhuo Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences , Wuhan 430071, China
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44
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Ge F, Huang W, Chen Z, Zhang C, Xiong Q, Bowler C, Yang J, Xu J, Hu H. Methylcrotonyl-CoA Carboxylase Regulates Triacylglycerol Accumulation in the Model Diatom Phaeodactylum tricornutum. THE PLANT CELL 2014; 26:1681-1697. [PMID: 24769481 PMCID: PMC4036579 DOI: 10.1105/tpc.114.124982] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The model marine diatom Phaeodactylum tricornutum can accumulate high levels of triacylglycerols (TAGs) under nitrogen depletion and has attracted increasing attention as a potential system for biofuel production. However, the molecular mechanisms involved in TAG accumulation in diatoms are largely unknown. Here, we employed a label-free quantitative proteomics approach to estimate differences in protein abundance before and after TAG accumulation. We identified a total of 1193 proteins, 258 of which were significantly altered during TAG accumulation. Data analysis revealed major changes in proteins involved in branched-chain amino acid (BCAA) catabolic processes, glycolysis, and lipid metabolic processes. Subsequent quantitative RT-PCR and protein gel blot analysis confirmed that four genes associated with BCAA degradation were significantly upregulated at both the mRNA and protein levels during TAG accumulation. The most significantly upregulated gene, encoding the β-subunit of methylcrotonyl-CoA carboxylase (MCC2), was selected for further functional studies. Inhibition of MCC2 expression by RNA interference disturbed the flux of carbon (mainly in the form of leucine) toward BCAA degradation, resulting in decreased TAG accumulation. MCC2 inhibition also gave rise to incomplete utilization of nitrogen, thus lowering biomass during the stationary growth phase. These findings help elucidate the molecular and metabolic mechanisms leading to increased lipid production in diatoms.
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Affiliation(s)
- Feng Ge
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Weichao Huang
- Diatom Biology Group, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Zhuo Chen
- Diatom Biology Group, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Chunye Zhang
- Diatom Biology Group, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Qian Xiong
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Chris Bowler
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'Ecole Normale Supérieure, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8197, Institut National de la Santé et de la Recherche Médicale U1024, Ecole Normale Supérieure, 75230 Paris cedex 05, France
| | - Juan Yang
- Diatom Biology Group, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Jin Xu
- Diatom Biology Group, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Hanhua Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China Diatom Biology Group, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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45
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Mapping the diatom redox-sensitive proteome provides insight into response to nitrogen stress in the marine environment. Proc Natl Acad Sci U S A 2014; 111:2740-5. [PMID: 24550302 DOI: 10.1073/pnas.1319773111] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Diatoms are ubiquitous marine photosynthetic eukaryotes responsible for approximately 20% of global photosynthesis. Little is known about the redox-based mechanisms that mediate diatom sensing and acclimation to environmental stress. Here we used a quantitative mass spectrometry-based approach to elucidate the redox-sensitive signaling network (redoxome) mediating the response of diatoms to oxidative stress. We quantified the degree of oxidation of 3,845 cysteines in the Phaeodactylum tricornutum proteome and identified approximately 300 redox-sensitive proteins. Intriguingly, we found redox-sensitive thiols in numerous enzymes composing the nitrogen assimilation pathway and the recently discovered diatom urea cycle. In agreement with this finding, the flux from nitrate into glutamine and glutamate, measured by the incorporation of (15)N, was strongly inhibited under oxidative stress conditions. Furthermore, by targeting the redox-sensitive GFP sensor to various subcellular localizations, we mapped organelle-specific oxidation patterns in response to variations in nitrogen quota and quality. We propose that redox regulation of nitrogen metabolism allows rapid metabolic plasticity to ensure cellular homeostasis, and thus is essential for the ecological success of diatoms in the marine ecosystem.
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46
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Veluchamy A, Lin X, Maumus F, Rivarola M, Bhavsar J, Creasy T, O'Brien K, Sengamalay NA, Tallon LJ, Smith AD, Rayko E, Ahmed I, Le Crom S, Farrant GK, Sgro JY, Olson SA, Bondurant SS, Allen AE, Allen A, Rabinowicz PD, Sussman MR, Bowler C, Tirichine L. Insights into the role of DNA methylation in diatoms by genome-wide profiling in Phaeodactylum tricornutum. Nat Commun 2013; 4:2091. [PMID: 23820484 DOI: 10.1038/ncomms3091] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 05/31/2013] [Indexed: 02/07/2023] Open
Abstract
DNA cytosine methylation is a widely conserved epigenetic mark in eukaryotes that appears to have critical roles in the regulation of genome structure and transcription. Genome-wide methylation maps have so far only been established from the supergroups Archaeplastida and Unikont. Here we report the first whole-genome methylome from a stramenopile, the marine model diatom Phaeodactylum tricornutum. Around 6% of the genome is intermittently methylated in a mosaic pattern. We find extensive methylation in transposable elements. We also detect methylation in over 320 genes. Extensive gene methylation correlates strongly with transcriptional silencing and differential expression under specific conditions. By contrast, we find that genes with partial methylation tend to be constitutively expressed. These patterns contrast with those found previously in other eukaryotes. By going beyond plants, animals and fungi, this stramenopile methylome adds significantly to our understanding of the evolution of DNA methylation in eukaryotes.
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Affiliation(s)
- Alaguraj Veluchamy
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure, CNRS UMR 8197 INSERM U1024, 46 rue d'Ulm, 75005 Paris, France
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Dagenais-Bellefeuille S, Morse D. Putting the N in dinoflagellates. Front Microbiol 2013; 4:369. [PMID: 24363653 PMCID: PMC3849724 DOI: 10.3389/fmicb.2013.00369] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 11/19/2013] [Indexed: 11/22/2022] Open
Abstract
The cosmopolitan presence of dinoflagellates in aquatic habitats is now believed to be a direct consequence of the different trophic modes they have developed through evolution. While heterotrophs ingest food and photoautotrophs photosynthesize, mixotrophic species are able to use both strategies to harvest energy and nutrients. These different trophic modes are of particular importance when nitrogen nutrition is considered. Nitrogen is required for the synthesis of amino acids, nucleic acids, chlorophylls, and toxins, and thus changes in the concentrations of various nitrogenous compounds can strongly affect both primary and secondary metabolism. For example, high nitrogen concentration is correlated with rampant cell division resulting in the formation of the algal blooms commonly called red tides. Conversely, nitrogen starvation results in cell cycle arrest and induces a series of physiological, behavioral and transcriptomic modifications to ensure survival. This review will combine physiological, biochemical, and transcriptomic data to assess the mechanism and impact of nitrogen metabolism in dinoflagellates and to compare the dinoflagellate responses with those of diatoms.
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Affiliation(s)
- Steve Dagenais-Bellefeuille
- Département de Sciences Biologiques, Institut de Recherche en Biologie Végétale, Université de Montréal Montréal QC, Canada
| | - David Morse
- Département de Sciences Biologiques, Institut de Recherche en Biologie Végétale, Université de Montréal Montréal QC, Canada
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Tirichine L, Lin X, Thomas Y, Lombard B, Loew D, Bowler C. Histone extraction protocol from the two model diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana. Mar Genomics 2013; 13:21-5. [PMID: 24315927 DOI: 10.1016/j.margen.2013.11.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/27/2013] [Accepted: 11/21/2013] [Indexed: 11/28/2022]
Abstract
Post-translational modifications of histones affect many biological processes by influencing higher order chromatin structure that affects gene and genome regulation. It is therefore important to develop methods for extracting histones while maintaining their native post-translational modifications. While histone extraction protocols have been developed in multicellular and single celled organisms such as yeast and Arabidopsis, they are inefficient in diatoms that have a silica cell wall that is likely to hinder histone extraction. We report in this work a rapid and reliable method for extraction of large amounts of high quality histones from the two model diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana. The protocol is an important enabling step permitting downstream applications such as western blotting and mass spectrometry.
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Affiliation(s)
- Leïla Tirichine
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197 INSERM U1024, 46 rue d'Ulm 75005 Paris, France.
| | - Xin Lin
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197 INSERM U1024, 46 rue d'Ulm 75005 Paris, France
| | - Yann Thomas
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197 INSERM U1024, 46 rue d'Ulm 75005 Paris, France
| | - Bérangère Lombard
- Institut Curie, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 26 rue d'Ulm 75248 Cedex 05 Paris, France
| | - Damarys Loew
- Institut Curie, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 26 rue d'Ulm 75248 Cedex 05 Paris, France
| | - Chris Bowler
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197 INSERM U1024, 46 rue d'Ulm 75005 Paris, France
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Bochenek M, Etherington GJ, Koprivova A, Mugford ST, Bell TG, Malin G, Kopriva S. Transcriptome analysis of the sulfate deficiency response in the marine microalga Emiliania huxleyi. THE NEW PHYTOLOGIST 2013; 199:650-62. [PMID: 23692606 DOI: 10.1111/nph.12303] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 03/27/2013] [Indexed: 05/03/2023]
Abstract
The response to sulfate deficiency of plants and freshwater green algae has been extensively analysed by system biology approaches. By contrast, seawater sulfate concentration is high and very little is known about the sulfur metabolism of marine organisms. Here, we used a combination of metabolite analysis and transcriptomics to analyse the response of the marine microalga Emiliania huxleyi as it acclimated to sulfate limitation. Lowering sulfate availability in artificial seawater from 25 to 5 mM resulted in significant reduction in growth and intracellular concentrations of dimethylsulfoniopropionate and glutathione. Sulfate-limited E. huxleyi cells showed increased sulfate uptake but sulfate reduction to sulfite did not seem to be regulated. Sulfate limitation in E. huxleyi affected expression of 1718 genes. The vast majority of these genes were upregulated, including genes involved in carbohydrate and lipid metabolism, and genes involved in the general stress response. The acclimation response of E. huxleyi to sulfate deficiency shows several similarities to the well-described responses of Arabidopsis and Chlamydomonas, but also has many unique features. This dataset shows that even though E. huxleyi is adapted to constitutively high sulfate concentration, it retains the ability to re-program its gene expression in response to reduced sulfate availability.
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Vandepoele K, Van Bel M, Richard G, Van Landeghem S, Verhelst B, Moreau H, Van de Peer Y, Grimsley N, Piganeau G. pico-PLAZA, a genome database of microbial photosynthetic eukaryotes. Environ Microbiol 2013; 15:2147-53. [DOI: 10.1111/1462-2920.12174] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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