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bioRxiv · 10.1101/334102

Transcriptome-wide analysis of auxin-induced carotenoid accumulation in Chlorella microalgae

Alsenani, F.·Wass, T.·Ma, R.·Eltanahy, E.·Netzel, M.·Schenk, P. M.
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Abstract

Microalgae are a commercially viable route for the production of carotenoids, including {beta}-carotene and astaxanthin. In the current study, the commercially relevant microalga, Chlorella sp. BR2 was treated with four plant hormones: indole-3-acetic acid, salicylic acid, abscisic acid and methyl jasmonate, over a range of dosages and screened for enhanced carotenoid production. Indole-3-acetic acid was the only hormone with an inductive effect on carotenoid accumulation. As such, the transcriptome under the condition with the highest carotenoid increase was profiled using RNA-Seq and expressed sequences reconstructed with de novo assembly. This allowed for the profiling of transcriptome-wide changes following auxin treatment, revealing the active pathway components of auxininduced carotenogenesis. Data analysis specified the differentially expressed genes involved in auxin biosynthesis and signal transduction, which suggest a close relationship to equivalent pathways in higher plants. However unlike in plants, the ancient ABP1/SCFSKP2A/IBR5-mediated pathways for auxin response likely acted as the primary signaling route in Chlorella. As carotenoids are precursors for abscisic acid, the findings suggest a causative link between auxin signaling and abiotic stress tolerance.\n\nHighlightTranscriptomics of plant hormone-treated Chlorella revealed the active pathway components of auxin-induced carotenogenesis and included the ancient ABP1/SCFSKP2A/IBR5-mediated pathways. The manuscript presents the first documented transcriptomic data of auxin-treated microalgae.

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Alsenani, F., Wass, T., Ma, R., Eltanahy, E., Netzel, M., Schenk, P. M.. 2018-05-30. Transcriptome-wide analysis of auxin-induced carotenoid accumulation in Chlorella microalgae. https://doi.org/10.1101/334102

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