Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis
This study aims to elucidate the mechanism of carbon partitioning towards starch and triacylglycerol (TAG) under nitrogen stress. Whole-transcriptome analysis was performed using RNA sequencing before being validated with qRT-PCR. The strain, Chlorella vulgaris UPSI-JRM01, exhibited a two-stage resp...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2020
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| Online Access: | http://psasir.upm.edu.my/id/eprint/86705/ http://psasir.upm.edu.my/id/eprint/86705/1/Mechanism%20of%20carbon%20partitioning%20towards%20.pdf |
| _version_ | 1848860267609325568 |
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| author | Nordin, Norazela Yusof, Norjan Maeda, Toshinari Mustapha, Nurul Asyifah Mohd Yusoff, Mohd Zulkhairi Raja Khairuddin, Raja Farhana |
| author_facet | Nordin, Norazela Yusof, Norjan Maeda, Toshinari Mustapha, Nurul Asyifah Mohd Yusoff, Mohd Zulkhairi Raja Khairuddin, Raja Farhana |
| author_sort | Nordin, Norazela |
| building | UPM Institutional Repository |
| collection | Online Access |
| description | This study aims to elucidate the mechanism of carbon partitioning towards starch and triacylglycerol (TAG) under nitrogen stress. Whole-transcriptome analysis was performed using RNA sequencing before being validated with qRT-PCR. The strain, Chlorella vulgaris UPSI-JRM01, exhibited a two-stage response to nitrogen stress: i) carbohydrate accumulation, plastid protein degradation and amino acid biosynthesis; and ii) lipid accumulation, carbohydrate degradation and DNA damage. In the first stage, the genes responsible for plastid protein degradation (CD4A), amino acid biosynthesis (arg, GLSN, AHCY, win1), carbon fixation (RuBisCO, GapC, fba, TK) and starch synthesis (SS, SBE2) were upregulated. In the second stage, the upregulation of genes responsible for starch degradation (SP), glycolysis (PFO, PK, ACS), fatty acid biosynthesis (FabH, accD) and TAG accumulation (DGAT2) were observed. By contrast, the components of photosystem I (PsbD, PsbC, PsbB), photosystem II (PsaA), cytochrome b6/f (PetA, PetG) and F-type ATPase (beta, alpha) were downregulated. The results suggested that nitrogen stress triggered high starch accumulation before the carbon was partitioned towards triacylglycerol (TAG) for long-term energy storage by two different pathways: chloroplastic TAG synthesis and glycerolipid metabolism. The starch build-up functions served as a rapid response to nitrogen stress, whereas subsequent lipid accumulation benefited the long-term storage of energy. This research provides in-depth understanding of the metabolic changes triggered by nitrogen stress. |
| first_indexed | 2025-11-15T12:42:31Z |
| format | Article |
| id | upm-86705 |
| institution | Universiti Putra Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T12:42:31Z |
| publishDate | 2020 |
| publisher | Elsevier |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | upm-867052021-11-09T07:26:31Z http://psasir.upm.edu.my/id/eprint/86705/ Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis Nordin, Norazela Yusof, Norjan Maeda, Toshinari Mustapha, Nurul Asyifah Mohd Yusoff, Mohd Zulkhairi Raja Khairuddin, Raja Farhana This study aims to elucidate the mechanism of carbon partitioning towards starch and triacylglycerol (TAG) under nitrogen stress. Whole-transcriptome analysis was performed using RNA sequencing before being validated with qRT-PCR. The strain, Chlorella vulgaris UPSI-JRM01, exhibited a two-stage response to nitrogen stress: i) carbohydrate accumulation, plastid protein degradation and amino acid biosynthesis; and ii) lipid accumulation, carbohydrate degradation and DNA damage. In the first stage, the genes responsible for plastid protein degradation (CD4A), amino acid biosynthesis (arg, GLSN, AHCY, win1), carbon fixation (RuBisCO, GapC, fba, TK) and starch synthesis (SS, SBE2) were upregulated. In the second stage, the upregulation of genes responsible for starch degradation (SP), glycolysis (PFO, PK, ACS), fatty acid biosynthesis (FabH, accD) and TAG accumulation (DGAT2) were observed. By contrast, the components of photosystem I (PsbD, PsbC, PsbB), photosystem II (PsaA), cytochrome b6/f (PetA, PetG) and F-type ATPase (beta, alpha) were downregulated. The results suggested that nitrogen stress triggered high starch accumulation before the carbon was partitioned towards triacylglycerol (TAG) for long-term energy storage by two different pathways: chloroplastic TAG synthesis and glycerolipid metabolism. The starch build-up functions served as a rapid response to nitrogen stress, whereas subsequent lipid accumulation benefited the long-term storage of energy. This research provides in-depth understanding of the metabolic changes triggered by nitrogen stress. Elsevier 2020-07 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/86705/1/Mechanism%20of%20carbon%20partitioning%20towards%20.pdf Nordin, Norazela and Yusof, Norjan and Maeda, Toshinari and Mustapha, Nurul Asyifah and Mohd Yusoff, Mohd Zulkhairi and Raja Khairuddin, Raja Farhana (2020) Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis. Biomass and Bioenergy, 138. art. no. 105600. pp. 1-14. ISSN 0961-9534; ESSN: 1873-2909 https://www.sciencedirect.com/science/article/pii/S0961953420301343 10.1016/j.biombioe.2020.105600 |
| spellingShingle | Nordin, Norazela Yusof, Norjan Maeda, Toshinari Mustapha, Nurul Asyifah Mohd Yusoff, Mohd Zulkhairi Raja Khairuddin, Raja Farhana Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis |
| title | Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis |
| title_full | Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis |
| title_fullStr | Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis |
| title_full_unstemmed | Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis |
| title_short | Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis |
| title_sort | mechanism of carbon partitioning towards starch and triacylglycerol in chlorella vulgaris under nitrogen stress through whole-transcriptome analysis |
| url | http://psasir.upm.edu.my/id/eprint/86705/ http://psasir.upm.edu.my/id/eprint/86705/ http://psasir.upm.edu.my/id/eprint/86705/ http://psasir.upm.edu.my/id/eprint/86705/1/Mechanism%20of%20carbon%20partitioning%20towards%20.pdf |