title: Genome-wide transcriptome analysis revealed organelle specific responses to temperature variations in algae.
abstract: Temperature is a critical environmental factor that affects microalgal growth. However, microalgal coping mechanisms for temperature variations are unclear. Here, we determined changes in transcriptome, total carbohydrate, total fatty acid methyl ester, and fatty acid composition of Tetraselmis sp. KCTC12432BP, a strain with a broad temperature tolerance range, to elucidate the tolerance mechanisms in response to large temperature variations. Owing to unavailability of genome sequence information, de novo transcriptome assembly coupled with BLAST analysis was performed using strand specific RNA-seq data. This resulted in 26,245 protein-coding transcripts, of which 83.7% could be annotated to putative functions. We identified more than 681 genes differentially expressed, suggesting an organelle-specific response to temperature variation. Among these, the genes related to the photosynthetic electron transfer chain, which are localized in the plastid thylakoid membrane, were upregulated at low temperature. However, the transcripts related to the electron transport chain and biosynthesis of phosphatidylethanolamine localized in mitochondria were upregulated at high temperature. These results show that the low energy uptake by repressed photosynthesis under low and high temperature conditions is compensated by different mechanisms, including photosystem I and mitochondrial oxidative phosphorylation, respectively. This study illustrates that microalgae tolerate different temperature conditions through organelle specific mechanisms.
authors.affiliation: Department of Biological Sciences, Korea advanced institute of Science and Technology, Daejon 305-701, Republic of Korea.
authors.forename: HyeonSeok
authors.initials: H
authors.lastname: Shin
authors.affiliation: Department of Biological Engineering, Inha University, Incheon 402-751, Republic of Korea.
authors.forename: Seong-Joo
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Department of Biological Sciences, Korea advanced institute of Science and Technology, Daejon 305-701, Republic of Korea.
authors.forename: Chan
authors.initials: C
authors.lastname: Yoo
authors.affiliation: Department of Biological Engineering, Inha University, Incheon 402-751, Republic of Korea.
authors.forename: Mi-Ae
authors.initials: MA
authors.lastname: Han
authors.affiliation: College of Pharmacy, Gachon University, Incheon 406-840, Republic of Korea.
authors.forename: Hookeun
authors.initials: H
authors.lastname: Lee
authors.affiliation: College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea.
authors.forename: Hyung-Kyoon
authors.initials: HK
authors.lastname: Choi
authors.affiliation: Department of Biological Sciences, Korea advanced institute of Science and Technology, Daejon 305-701, Republic of Korea.
authors.forename: Suhyung
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Biological Engineering, Inha University, Incheon 402-751, Republic of Korea.
authors.forename: Choul-Gyun
authors.initials: CG
authors.lastname: Lee
authors.affiliation: Department of Biological Sciences, Korea advanced institute of Science and Technology, Daejon 305-701, Republic of Korea.
authors.forename: Byung-Kwan
authors.initials: BK
authors.lastname: Cho
mesh_terms: D002478:Cells, Cultured; D004579:Electron Transport / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods; D016678:Genome / Q000235:genetics; D055106:Genome-Wide Association Study / Q000379:methods; D058086:Microalgae / Q000235:genetics; D008928:Mitochondria / Q000235:genetics; D015388:Organelles / Q000235:genetics*; D010085:Oxidative Phosphorylation; D000459:Phaeophyceae / Q000235:genetics*; D010714:Phosphatidylethanolamines / Q000235:genetics; D010788:Photosynthesis / Q000235:genetics; D045331:Photosystem I Protein Complex / Q000235:genetics; D013696:Temperature; D020524:Thylakoids / Q000235:genetics; D059467:Transcriptome / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D010714:Phosphatidylethanolamines; D045331:Photosystem I Protein Complex; C483858:phosphatidylethanolamine