Lipid remodeling regulator 1 ( LRL 1) is differently involved in the phosphorus‐depletion response from PSR 1 in Chlamydomonas reinhardtii

Autor: Masataka Kajikawa, Hideya Fukuzawa, Kanami Sesoko, Nur Akmalia Hidayati, Takeshi Obayashi, Masako Iwai, Takashi Yamano, Kunihiro Suda, Nozomu Sakurai, Hiroyuki Ohta, Yui Yamada-Oshima, Mie Shimojima, Koichi Hori
Rok vydání: 2019
Předmět:
Zdroj: The Plant Journal
ISSN: 1365-313X
0960-7412
DOI: 10.1111/tpj.14473
Popis: The elucidation of lipid metabolism in microalgae has attracted broad interest, as their storage lipid, triacylglycerol (TAG), can be readily converted into biofuel via transesterification. TAG accumulates in the form of oil droplets, especially when cells undergo nutrient deprivation, such as for nitrogen (N), phosphorus (P), or sulfur (S). TAG biosynthesis under N‐deprivation has been comprehensively studied in the model microalga Chlamydomonas reinhardtii, during which TAG accumulates dramatically. However, the resulting rapid breakdown of chlorophyll restricts overall oil yield productivity and causes cessation of cell growth. In contrast, P‐deprivation results in oil accumulation without disrupting chloroplast integrity. We used a reverse genetics approach based on co‐expression analysis to identify a transcription factor (TF) that is upregulated under P‐depleted conditions. Transcriptomic analysis revealed that the mutants showed repression of genes typically associated with lipid remodeling under P‐depleted conditions, such as sulfoquinovosyl diacylglycerol 2 (SQD2), diacylglycerol acyltransferase (DGTT1), and major lipid droplet protein (MLDP). As accumulation of sulfoquinovosyl diacylglycerol and TAG were suppressed in P‐depleted mutants, we designated the protein as Lipid Remodeling reguLator 1 (LRL1). LRL1 mutants showed slower growth under P‐depletion. Moreover, cell size in the mutant was significantly reduced, and TAG and starch accumulation per cell were decreased. Transcriptomic analysis also suggested the repression of several genes typically upregulated in adaptation to P‐depletion that are associated with the cell cycle and P and lipid metabolism. Thus, our analysis of LRL1 provides insights into P‐allocation and lipid remodeling under P‐depleted conditions in C. reinhardtii.
藻類のオイル生産を制御する因子を同定 --有用脂質生産の自在制御に向け大きな一歩--. 京都大学プレスリリース. 2019-08-05.
Scientists identify protein factors increasing yield of a biofuel precursor in microscopic algae. 京都大学プレスリリース. 2019-08-02.
Databáze: OpenAIRE
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