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Crehan O, Davy SK, Grover R, Ferrier-Pagès C. Nutrient depletion and heat stress impair the assimilation of nitrogen compounds in a scleractinian coral. J Exp Biol 2024; 227:jeb246466. [PMID: 38563292 DOI: 10.1242/jeb.246466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 03/21/2024] [Indexed: 04/04/2024]
Abstract
Concentrations of dissolved nitrogen in seawater can affect the resilience of the cnidarian-dinoflagellate symbiosis to climate change-induced bleaching. However, it is not yet known how the assimilation and translocation of the various nitrogen forms change during heat stress, nor how the symbiosis responds to nutrient depletion, which may occur due to increasing water stratification. Here, the tropical scleractinian coral Stylophora pistillata, in symbiosis with dinoflagellates of the genus Symbiodinium, was grown at different temperatures (26°C, 30°C and 34°C), before being placed in nutrient-replete or -depleted seawater for 24 h. The corals were then incubated with 13C-labelled sodium bicarbonate and different 15N-labelled nitrogen forms (ammonium, urea and dissolved free amino acids) to determine their assimilation rates. We found that nutrient depletion inhibited the assimilation of all nitrogen sources studied and that heat stress reduced the assimilation of ammonium and dissolved free amino acids. However, the host assimilated over 3-fold more urea at 30°C relative to 26°C. Overall, both moderate heat stress (30°C) and nutrient depletion individually decreased the total nitrogen assimilated by the symbiont by 66%, and combined, they decreased assimilation by 79%. This led to the symbiotic algae becoming nitrogen starved, with the C:N ratio increasing by over 3-fold at 34°C, potentially exacerbating the impacts of coral bleaching.
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Affiliation(s)
- Oscar Crehan
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
| | - Renaud Grover
- Marine Department, Centre Scientifique de Monaco, MC 98000 Monaco, Principality of Monaco
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Lei JD, Li Q, Zhang SB, Lv YY, Zhai HC, Wei S, Ma PA, Hu YS. Transcriptomic and biochemical analyses revealed antifungal mechanism of trans-anethole on Aspergillus flavus growth. Appl Microbiol Biotechnol 2023; 107:7213-7230. [PMID: 37733053 DOI: 10.1007/s00253-023-12791-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 09/04/2023] [Accepted: 09/12/2023] [Indexed: 09/22/2023]
Abstract
Plant volatile compounds have great potential for preventing and controlling fungal spoilage in post-harvest grains. Recently, we have reported the antifungal effects of trans-anethole, the main volatile constituent of the Illicium verum fruit, on Aspergillus flavus. In this study, the inhibitory mechanisms of trans-anethole against the growth of A. flavus mycelia were investigated using transcriptomic and biochemical analyses. Biochemical and transcriptomic changes in A. flavus mycelia were evaluated after exposure to 0.2 μL/mL trans-anethole. Scanning electron microscopy showed that trans-anethole treatment resulted in the surface wrinkling of A. flavus mycelia, and calcofluor white staining confirmed that trans-anethole treatment disrupted the mycelial cell wall structure. Annexin V-fluorescein isothiocyanate/propidium iodide double staining suggested that trans-anethole induced apoptosis in A. flavus mycelia. Reduced mitochondrial membrane potential and DNA damage were observed in trans-anethole-treated A. flavus mycelia using 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine and 4',6-diamidino-2-phenylindole staining, respectively. 2',7'- Dichloro-dihydro-fluorescein diacetate staining and biochemical assays demonstrated that trans-anethole treatment cause the accumulation of reactive oxygen species in the A. flavus mycelia. Transcriptome results showed that 1673 genes were differentially expressed in A. flavus mycelia exposed to trans-anethole, which were mainly associated with multidrug transport, oxidative phosphorylation, citric acid cycle, ribosomes, and cyclic adenosine monophosphate signaling. We propose that trans-anethole can inhibit the growth of A. flavus mycelia by disrupting the cell wall structure, blocking the multidrug transport process, disturbing the citric acid cycle, and inducing apoptosis. This study provides new insights into the inhibitory mechanism of trans-anethole on A. flavus mycelia and will be helpful for the development of natural fungicides. KEY POINTS: • Biochemical analyses of A. flavus mycelia exposed to trans-anethole were performed • Transcriptomic changes in trans-anethole-treated A. flavus mycelia were analyzed • An inhibitory mechanism of trans-anethole on the growth of A. flavus mycelia was proposed.
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Affiliation(s)
- Jun-Dong Lei
- School of Biological Engineering, Henan University of Technology, 100 Lianhua Street, Zhengzhou, 450001, People's Republic of China
| | - Qiong Li
- School of Biological Engineering, Henan University of Technology, 100 Lianhua Street, Zhengzhou, 450001, People's Republic of China
| | - Shuai-Bing Zhang
- School of Biological Engineering, Henan University of Technology, 100 Lianhua Street, Zhengzhou, 450001, People's Republic of China.
| | - Yang-Yong Lv
- School of Biological Engineering, Henan University of Technology, 100 Lianhua Street, Zhengzhou, 450001, People's Republic of China
| | - Huan-Chen Zhai
- School of Biological Engineering, Henan University of Technology, 100 Lianhua Street, Zhengzhou, 450001, People's Republic of China
| | - Shan Wei
- School of Biological Engineering, Henan University of Technology, 100 Lianhua Street, Zhengzhou, 450001, People's Republic of China
| | - Ping-An Ma
- School of Biological Engineering, Henan University of Technology, 100 Lianhua Street, Zhengzhou, 450001, People's Republic of China
| | - Yuan-Sen Hu
- School of Biological Engineering, Henan University of Technology, 100 Lianhua Street, Zhengzhou, 450001, People's Republic of China
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3
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He W, Ke X, Li T, Wu Y, Tang X, Chen W, Liu T, Du H. Comparison and improvement of RNA extraction methods in Sargassum (Phaeophyta). JOURNAL OF PHYCOLOGY 2023; 59:822-834. [PMID: 37656660 DOI: 10.1111/jpy.13375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 09/03/2023]
Abstract
Sargassum (Sargassaceae) is widely distributed globally and plays an important role in regulating climate change, but the landscape of genomes and transcripts is less known. High-quality nucleic acids are the basis for molecular biology experiments such as high-throughput sequencing. Although extensive studies have documented methods of RNA extraction, these methods are not very applicable to Sargassum, which contains high levels of polysaccharides and polyphenols. To find a suitable method to improve the quality of RNA extracted, we compared and modified several popular RNA extraction methods and screened one practical method with three specific Sargassum spp. The results showed that three CTAB methods (denoted as Methods 1, 2, and 3) and the RNAprep Pure Plant Kit (denoted as Method 4) could, with slight modifications, effectively isolate RNA from Sargassum species, except for Method 4 used with S. fusiforme. By performing further screening, we determined Method 4 was the best choice for S. hemiphyllum and S. henslowianum, as revealed by RNA yields, RNA Integrity Number (RIN), extraction time, and unigene mapped ratio. For S. fusiforme, Methods 1, 2, and 3 showed no obvious differences among the yields, quality, or time to perform. In addition, one other method was tested, but we found the quality of the RNA extracted by TRIzol reagent methods (denoted as Method 5) performed the worst when compared with the above four methods. Therefore, our study provides four suitable methods for RNA extraction in Sargassum and is essential for future genetic exploration of Sargassum.
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Affiliation(s)
- Weiling He
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, China
| | - Xiao Ke
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, China
| | - Tangcheng Li
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, China
| | - Yuming Wu
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, China
| | - Xianming Tang
- Hainan Provincial Key Laboratory of Tropical Maricultural Technology, Hainan Academy of Ocean and Fisheries Sciences, Haikou, China
| | - Weizhou Chen
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, China
| | - Tao Liu
- State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Hong Du
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, China
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Chen T, Liu Y, Song S, Bai J, Li C. Full-length transcriptome analysis of the bloom-forming dinoflagellate Akashiwo sanguinea by single-molecule real-time sequencing. Front Microbiol 2022; 13:993914. [PMID: 36325025 PMCID: PMC9618608 DOI: 10.3389/fmicb.2022.993914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
The dinoflagellate Akashiwo sanguinea is a harmful algal species and commonly observed in estuarine and coastal waters around the world. Harmful algal blooms (HABs) caused by this species lead to serious environmental impacts in the coastal waters of China since 1998 followed by huge economic losses. However, the full-length transcriptome information of A. sanguinea is still not fully explored, which hampers basic genetic and functional studies. Herein, single-molecule real-time (SMRT) sequencing technology was performed to characterize the full-length transcript in A. sanguinea. Totally, 83.03 Gb SMRT sequencing clean reads were generated, 983,960 circular consensus sequences (CCS) with average lengths of 3,061 bp were obtained, and 81.71% (804,016) of CCS were full-length non-chimeric reads (FLNC). Furthermore, 26,461 contigs were obtained after being corrected with Illumina library sequencing, with 20,037 (75.72%) successfully annotated in the five public databases. A total of 13,441 long non-coding RNA (lncRNA) transcripts, 3,137 alternative splicing (AS) events, 514 putative transcription factors (TFs) members from 23 TF families, and 4,397 simple sequence repeats (SSRs) were predicted, respectively. Our findings provided a sizable insights into gene sequence characteristics of A. sanguinea, which can be used as a reference sequence resource for A. sanguinea draft genome annotation, and will contribute to further molecular biology research on this harmful bloom algae.
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Affiliation(s)
- Tiantian Chen
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, China
- Key Laboratory of Marine Environment and Ecology, Ocean University of China, Qingdao, China
| | - Yun Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Shuqun Song
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Jie Bai
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, China
- Key Laboratory of Marine Environment and Ecology, Ocean University of China, Qingdao, China
| | - Caiwen Li
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- *Correspondence: Caiwen Li,
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Oliveira CYB, Abreu JL, Santos EP, Matos ÂP, Tribuzi G, Oliveira CDL, Veras BO, Bezerra RS, Müller MN, Gálvez AO. Light induces peridinin and docosahexaenoic acid accumulation in the dinoflagellate Durusdinium glynnii. Appl Microbiol Biotechnol 2022; 106:6263-6276. [PMID: 35972515 DOI: 10.1007/s00253-022-12131-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/02/2022] [Accepted: 08/03/2022] [Indexed: 11/02/2022]
Abstract
Peridinin is a light-harvesting carotenoid present in phototrophic dinoflagellates and has great potential for new drug applications and cosmetics development. Herein, the effects of irradiance mediated by light-emitting diodes on growth performance, carotenoid and fatty acid profiles, and antioxidant activity of the endosymbiotic dinoflagellate Durusdinium glynnii were investigated. The results demonstrate that D. glynnii is particularly well adapted to low-light conditions; however, it can be high-light-tolerant. In contrast to other light-harvesting carotenoids, the peridinin accumulation in D. glynnii occurred during high-light exposure. The peridinin to chlorophyll-a ratio varied as a function of irradiance, while the peridinin to total carotenoids ratio remained stable. Under optimal irradiance for growth, there was a peak in docosahexaenoic acid (DHA) bioaccumulation. This study contributes to the understanding of the photoprotective role of peridinin in endosymbiont dinoflagellates and highlights the antioxidant activity of peridinin-rich extracts. KEY POINTS: • Peridinin has a protective role against chlorophyll photo-oxidation • High light conditions induce cellular peridinin accumulation • D. glynnii accumulates high amounts of DHA under optimal light supply.
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Affiliation(s)
- Carlos Yure B Oliveira
- Department of Fishing and Aquaculture, Federal Rural University of Pernambuco, St. Dom Manuel de Medeiros, Dois Irmãos, Recife, 52171-900, Brazil.
| | - Jéssika L Abreu
- Department of Fishing and Aquaculture, Federal Rural University of Pernambuco, St. Dom Manuel de Medeiros, Dois Irmãos, Recife, 52171-900, Brazil
| | - Elizabeth P Santos
- Department of Fishing and Aquaculture, Federal Rural University of Pernambuco, St. Dom Manuel de Medeiros, Dois Irmãos, Recife, 52171-900, Brazil
| | - Ângelo P Matos
- Center of Agricultural Sciences, Federal University of Santa Catarina, Florianópolis, 88034-001, Brazil
| | - Giustino Tribuzi
- Department of Food Science and Technology, Federal University of Santa Catarina, Florianopolis, 88034-801, Brazil
| | - Cicero Diogo L Oliveira
- Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, 57072-900, Brazil
| | - Bruno O Veras
- Department of Biochemistry, Federal University of Pernambuco, Recife, 50740-550, Brazil
| | - Railson S Bezerra
- Department of Biochemistry, Federal University of Pernambuco, Recife, 50740-550, Brazil
| | - Marius N Müller
- Department of Oceanography, Federal University of Pernambuco, Recife, 50740-550, Brazil
| | - Alfredo O Gálvez
- Department of Fishing and Aquaculture, Federal Rural University of Pernambuco, St. Dom Manuel de Medeiros, Dois Irmãos, Recife, 52171-900, Brazil
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6
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Ji N, Wang J, Zhang Z, Chen L, Xu M, Yin X, Shen X. Transcriptomic response of the harmful algae Heterosigma akashiwo to polyphosphate utilization and phosphate stress. HARMFUL ALGAE 2022; 117:102267. [PMID: 35944950 DOI: 10.1016/j.hal.2022.102267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/24/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Phosphorus (P) is one of the major macronutrients necessary for phytoplankton growth. In some parts of the ocean, however, P is frequently scarce, hence, there is limited phytoplankton growth. To cope with P deficiency, phytoplankton evolved a variety of strategies, including, utilization of different P sources. Polyphosphate (polyP) is ubiquitously present and serves an essential function in aquatic environments, but it is unclear if and how this polymer is utilized by phytoplankton. Here, we examined the physiological and molecular responses of the widely present harmful algal bloom (HAB) species, Heterosigma akashiwo in polyP utilization, and in coping with P-deficiency. Our results revealed that two forms of inorganic polyP, namely, sodium tripolyphosphate and sodium hexametaphosphate, support H. akashiwo growth as efficiently as orthophosphate. However, few genes involved in polyP utilization have been identified. Under P-deficient conditions, genes associated with P transport, dissolved organic P utilization, sulfolipid synthesis, and energy production, were markedly elevated. In summary, our results indicate that polyP is bioavailable to H. akashiwo, and this HAB species have evolved a comprehensive strategy to cope with P deficiency.
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Affiliation(s)
- Nanjing Ji
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; Jiangsu Marine Resources Development Research Institute, Lianyungang 222005, China; CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Junyue Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Zhenzhen Zhang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Lei Chen
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Mingyang Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Xueyao Yin
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Xin Shen
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
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7
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Pang CZ, Ip YK, Chew SF. Ammonia transporter 2 as a molecular marker to elucidate the potentials of ammonia transport in phylotypes of Symbiodinium, Cladocopium and Durusdinium in the fluted giant clam, Tridacna squamosa. Comp Biochem Physiol A Mol Integr Physiol 2022; 269:111225. [PMID: 35460895 DOI: 10.1016/j.cbpa.2022.111225] [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: 11/15/2021] [Revised: 04/17/2022] [Accepted: 04/17/2022] [Indexed: 12/15/2022]
Abstract
Giant clams harbor coccoid Symbiodiniaceae dinoflagellates that are phototrophic. These dinoflagellates generally include multiple phylotypes (species) of Symbiodinium, Cladocopium, and Durusdinium in disparate proportions depending on the environmental conditions. The coccoid symbionts can share photosynthate with the clam host, which in return supply them with nutrients containing inorganic carbon, nitrogen and phosphorus. Symbionts can recycle nitrogen by absorbing and assimilating the endogenous ammonia produced by the host. This study aimed to use the transcript levels of ammonia transporter 2 (AMT2) in Symbiodinium (Symb-AMT2), Cladocopium (Clad-AMT2) and Durusdinium (Duru-AMT2) as molecular indicators to estimate the potential of ammonia transport in these three genera of Symbiodiniaceae dinoflagellates in different organs of the fluted giant clam, Tridacna squamosa, obtained from Vietnam. We also determined the transcript levels of form II ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcII) and nitrate transporter 2 (NRT2) in Symbiodinium (Symb-rbcII; Symb-NRT2), Cladocopium (Clad-rbcII; Clad-NRT2) and Durusdinium (Duru-rbcII; Duru-NRT2), in order to examine the potential of ammonia transport with reference to the potentials of phototrophy or NO3- uptake independent of the quantities and proportion of these Symbiodiniaceae phylotypes. Our results indicated for the first time that phylotypes of Symbiodinium and Cladocopium could have different potentials of ammonia transport, and that phylotypes of Symbiodinium might have higher potential of NO3- transport than ammonia transport. They also suggested that Symbiodiniaceae phylotypes residing in different organs of T. squamosa could have disparate potentials of ammonia transport, alluding to the functional diversity among phylotypes of coccoid Symbiodinium, Cladocopium, and Durusdinium.
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Affiliation(s)
- Caryn Z Pang
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616, Republic of Singapore
| | - Yuen K Ip
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore 117543, Republic of Singapore
| | - Shit F Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616, Republic of Singapore.
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8
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Perera IA, Abinandan S, Subashchandrabose SR, Venkateswarlu K, Naidu R, Megharaj M. Impact of Nitrate and Ammonium Concentrations on Co-Culturing of Tetradesmus obliquus IS2 with Variovorax paradoxus IS1 as Revealed by Phenotypic Responses. MICROBIAL ECOLOGY 2022; 83:951-959. [PMID: 34363515 DOI: 10.1007/s00248-021-01832-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Mutual interactions in co-cultures of microalgae and bacteria are well known for establishing consortia and nutrient uptake in aquatic habitats, but the phenotypic changes in terms of morphological, physiological, and biochemical attributes that drive these interactions have not been clearly understood. In this novel study, we demonstrated the phenotypic response in a co-culture involving a microalga, Tetradesmus obliquus IS2, and a bacterium, Variovorax paradoxus IS1, grown with varying concentrations of two inorganic nitrogen sources. Modified Bold's basal medium was supplemented with five ratios (%) of NO3-N:NH4-N (100:0, 75:25, 50:50, 25:75, and 0:100), and by maintaining N:P Redfield ratio of 16:1. The observed morphological changes in microalga included an increase in granularity and a broad range of cell sizes under the influence of increased ammonium levels. Co-culturing in presence of NO3-N alone or combination with NH4-N up to equimolar concentrations resulted in complete nitrogen uptake, increased growth in both the microbial strains, and enhanced accumulation of carbohydrates, proteins, and lipids. Total chlorophyll content in microalga was also significantly higher when it was grown as a co-culture with NO3-N and NH4-N up to a ratio of 50:50. Significant upregulation in the synthesis of amino acids and sugars and downregulation of organic acids were evident with higher ammonium uptake in the co-culture, indicating the regulation of carbon and nitrogen assimilation pathways and energy synthesis. Our data suggest that the co-culture of strains IS1 and IS2 could be exploited for effluent treatment by considering the concentrations of inorganic sources, particularly ammonium, in the wastewaters.
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Affiliation(s)
- Isiri Adhiwarie Perera
- Global Centre for, Environmental Remediation (GCER), School of Engineering, Science and Environment, The University of Newcastle, ATC Building, University Drive, NSW, 2308, Callaghan, Australia
| | - Sudharsanam Abinandan
- Global Centre for, Environmental Remediation (GCER), School of Engineering, Science and Environment, The University of Newcastle, ATC Building, University Drive, NSW, 2308, Callaghan, Australia
- Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), The University of Newcastle, ATC Building, University Drive, Callaghan, NSW, 2308, Australia
| | - Suresh R Subashchandrabose
- Global Centre for, Environmental Remediation (GCER), School of Engineering, Science and Environment, The University of Newcastle, ATC Building, University Drive, NSW, 2308, Callaghan, Australia
| | - Kadiyala Venkateswarlu
- Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapuramu, 515003, Andhra Pradesh, India
| | - Ravi Naidu
- Global Centre for, Environmental Remediation (GCER), School of Engineering, Science and Environment, The University of Newcastle, ATC Building, University Drive, NSW, 2308, Callaghan, Australia
- Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), The University of Newcastle, ATC Building, University Drive, Callaghan, NSW, 2308, Australia
| | - Mallavarapu Megharaj
- Global Centre for, Environmental Remediation (GCER), School of Engineering, Science and Environment, The University of Newcastle, ATC Building, University Drive, NSW, 2308, Callaghan, Australia.
- Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), The University of Newcastle, ATC Building, University Drive, Callaghan, NSW, 2308, Australia.
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9
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Zhao H, Wang Y, Liu Y, Yin K, Wang D, Li B, Yu H, Xing M. ROS-Induced Hepatotoxicity under Cypermethrin: Involvement of the Crosstalk between Nrf2/Keap1 and NF-κB/iκB-α Pathways Regulated by Proteasome. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6171-6183. [PMID: 33843202 DOI: 10.1021/acs.est.1c00515] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Cypermethrin (CMN) is a man-made insecticide, and its abuse has led to potential adverse effects, particularly in sensitive populations such as aquatic organisms. The present study was focused on the toxic phenotype and detoxification mechanism in grass carp (Ctenopharyngodon idella) after treatment with waterborne CMN (0.651 μg/L) for 6 weeks in vivo or 6.392 μM for 24 h in vitro. In vivo, we describe the toxic phenotype of the liver of grass carp in terms of pathological changes, serum transaminase levels, oxidative stress indexes, and apoptosis rates. RNA-Seq analysis (2 × 3 cDNA libraries) suggested a compromise of proteasome and oxidative phosphorylation signaling pathways under CMN exposure. Thus, these two pathways were chosen for the in vitro study, which suggested that the CMN intoxication-induced proteasome pathway caused hepatotoxicity in the liver cell line of grass carp (L8824 cells). Moreover, pretreatment with MG132, a proteasome inhibitor, displayed protection against the toxic effects of CMN by enhancing antioxidative and anti-inflammatory capability by directly inhibiting the proteasomal degradation of nuclear factor erythroid-2 related factor (Nrf2) and IκB-α, thus turning on the transcription of downstream genes of Nrf2 and NF-κB, respectively. Taken together, these results suggest proteasome activity as a reason for CMN-induced hepatotoxicity.
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Affiliation(s)
- Hongjing Zhao
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin, Heilongjiang 150040, PR China
| | - Yu Wang
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin, Heilongjiang 150040, PR China
| | - Yachen Liu
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin, Heilongjiang 150040, PR China
| | - Kai Yin
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin, Heilongjiang 150040, PR China
| | - Dongxu Wang
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin, Heilongjiang 150040, PR China
| | - Baoying Li
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin, Heilongjiang 150040, PR China
| | - Hongxian Yu
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin, Heilongjiang 150040, PR China
| | - Mingwei Xing
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin, Heilongjiang 150040, PR China
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Li H, Li L, Yu L, Yang X, Shi X, Wang J, Li J, Lin S. Transcriptome profiling reveals versatile dissolved organic nitrogen utilization, mixotrophy, and N conservation in the dinoflagellate Prorocentrum shikokuense under N deficiency. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 763:143013. [PMID: 33203560 DOI: 10.1016/j.scitotenv.2020.143013] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 06/11/2023]
Abstract
Harmful algal blooms formed by certain dinoflagellate species often occur when environmental nitrogen nutrients (N) are limited. However, the molecular mechanism by which dinoflagellates adapt to low N environments is poorly understood. In this study, we characterized the transcriptomic responses of Prorocentrum shikokuense to N deficiency, along with its physiological impact. Under N deficiency, P. shikokuense cultures exhibited growth inhibition, a reduction in cell size, and decreases in cellular chlorophyll a and nitrogen contents but an increase in carbon content. Accordingly, gene expression profiles indicated that carbon fixation and catabolism and fatty acid metabolism were enhanced. Transporter genes of nitrate/nitrite, ammonium, urea, and amino acids were significantly upregulated, indicating that P. shikokuense cells invest to enhance the uptake of available dissolved N. Notably, upregulated genes included those involved in endocytosis and phagosomes, evidence that P. shikokuense is a mixotrophic organism that activates phagotrophy to overcome N deficiency. Additionally, vacuolar amino acid transporters, the urea cycle, and urea hydrolysis genes were upregulated, indicating N recycling within the cells under N deficiency. Our study indicates that P. shikokuense copes with N deficiency by economizing nitrogen use and adopting multiple strategies to maximize N acquisition and reuse while maintaining carbon fixation. The remarkable low N adaptability may confer competitive advantages to P. shikokuense for forming harmful blooms in DIN-limited environments.
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Affiliation(s)
- Hongfei Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Department of Marine Sciences, University of Connecticut, Groton CT06405, USA
| | - Ling Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Liying Yu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Xiaohong Yang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Xinguo Shi
- College of Biological Science and Engineering, Fuzhou University, Fujian 350116, China
| | - Jierui Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Jiashun Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Department of Marine Sciences, University of Connecticut, Groton CT06405, USA..
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Kirk AL, Clowez S, Lin F, Grossman AR, Xiang T. Transcriptome Reprogramming of Symbiodiniaceae Breviolum minutum in Response to Casein Amino Acids Supplementation. Front Physiol 2020; 11:574654. [PMID: 33329024 PMCID: PMC7710908 DOI: 10.3389/fphys.2020.574654] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 09/18/2020] [Indexed: 01/08/2023] Open
Abstract
Dinoflagellates in the family Symbiodiniaceae can live freely in ocean waters or form a symbiosis with a variety of cnidarians including corals, sea anemones, and jellyfish. Trophic plasticity of Symbiodiniaceae is critical to its ecological success as it moves between environments. However, the molecular mechanisms underlying these trophic shifts in Symbiodiniaceae are still largely unknown. Using Breviolum minutum strain SSB01 (designated SSB01) as a model, we showed that Symbiodiniaceae go through a physiological and transcriptome reprogramming when the alga is grown with the organic nitrogen containing nutrients in hydrolyzed casein, but not with inorganic nutrients. SSB01 grows at a much faster rate and maintains stable photosynthetic efficiency when supplemented with casein amino acids compared to only inorganic nutrients or seawater. These physiological changes are driven by massive transcriptome changes in SSB01 supplemented with casein amino acids. The levels of transcripts encoding proteins involved in altering DNA conformation such as DNA topoisomerases, histones, and chromosome structural components were all significantly changed. Functional enrichment analysis also revealed processes involved in translation, ion transport, generation of second messengers, and phosphorylation. The physiological and molecular changes that underlie in vitro trophic transitions in Symbiodiniaceae can serve as an orthogonal platform to further understand the factors that impact the Symbiodiniaceae lifestyle.
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Affiliation(s)
- Andrea L. Kirk
- Department of Biological Sciences, The University of North Carolina at Charlotte, Charlotte, NC, United States
| | - Sophie Clowez
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, United States
| | - Fan Lin
- Brightseed Inc., San Francisco, CA, United States
| | - Arthur R. Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, United States
| | - Tingting Xiang
- Department of Biological Sciences, The University of North Carolina at Charlotte, Charlotte, NC, United States
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