Overexpression of Plastid Acetyl-CoA Carboxylase Confers Stress Tolerances with Increased Levels of Unsaturated Fatty Acids in the Marine Diatom Phaeodactylum tricornutum

IF 2.6 3区生物学 Q3 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Marine Biotechnology Pub Date : 2025-03-26 DOI:10.1007/s10126-025-10446-9

Masakazu Toyoshima, Hajime Okuda, Yuya Okada, Kohei Yoneda, Ginga Shimakawa, Yusuke Matsuda

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引用次数: 0

Abstract

Acetyl-coenzyme A carboxylases (ACCs) catalyze the initial reaction of fatty acid (FA) biosynthesis. The marine diatom Phaeodactylum tricornutum has two nuclear-encoded ACCs (PtACC1 (Phatr3_EG01955) and PtACC2 (Phatr3_J55209)), both which are homomeric and predicted to be localized in the plastids and the cytosol, respectively. In this study, we focused on stromal ACC1 by constructing P. tricornutum strains expressing GFP-tagged PtACC1 (ACCG strains) and confirmed that PtACC1 was localized in or around the pyrenoid. Here, we showed that unsaturated FAs (UFAs) composing the thylakoid membrane lipids increased in PtACC1 strains grown under high light conditions (190 µmol photons m⁻² s⁻¹), and that the content of triacylglycerol (TAG) and unsaturation ratios in TAG increased under oxidative stresses (with added 50 µM H₂O₂). ACCG strains showed faster growth rates than wild type under high light and/or oxidative stress conditions. These results suggest that cell proliferation is maintained by an accelerated recovery of PSII due to the increased UFAs in the thylakoid membrane in ACCG strains grown in high light, and that increased UFAs in ACCG cells enhanced the tolerance to oxidative stresses presumably due to the increased scavenging capacity of UFAs against reactive oxygen species. The introduction of plastidic ACC resulted in stimulating supply of UFAs to specific lipids that in turn enhanced tolerance to various stresses.

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过度表达的质体乙酰辅酶a羧化酶赋予海洋硅藻三角藻不饱和脂肪酸水平增加的胁迫耐受性

乙酰辅酶A羧化酶（ACCs）催化脂肪酸（FA）生物合成的初始反应。海洋硅藻褐藻（Phaeodactylum tricornutum）具有两个核编码acc (PtACC1 （Phatr3_EG01955）和PtACC2 (Phatr3_J55209))，这两个acc是同源的，预计分别定位于质体和细胞质中。在本研究中，我们通过构建表达gfp标记PtACC1的tricornutum菌株（ACCG菌株）来关注间质ACC1，并证实PtACC1定位于类pyrenoid或其周围。在这里，我们发现在强光条件下（190µmol光子m−2 s−1）生长的PtACC1菌株中，组成类囊体膜脂的不饱和脂肪酸（UFAs）增加，氧化应激（添加50µm H2O2）下，三酰基甘油（TAG）的含量和TAG的不饱和比例增加。在强光和/或氧化应激条件下，ACCG菌株的生长速度比野生型快。这些结果表明，在强光下生长的ACCG菌株中，由于类囊体膜中UFAs的增加，PSII的加速恢复维持了细胞增殖，并且ACCG细胞中UFAs的增加增强了对氧化应激的耐受性，这可能是由于UFAs对活性氧的清除能力增加。可塑ACC的引入刺激了特定脂质的ufa供应，从而增强了对各种压力的耐受性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Marine Biotechnology 工程技术-海洋与淡水生物学

CiteScore

4.80

自引率

3.30%

发文量

审稿时长

2 months

期刊介绍： Marine Biotechnology welcomes high-quality research papers presenting novel data on the biotechnology of aquatic organisms. The journal publishes high quality papers in the areas of molecular biology, genomics, proteomics, cell biology, and biochemistry, and particularly encourages submissions of papers related to genome biology such as linkage mapping, large-scale gene discoveries, QTL analysis, physical mapping, and comparative and functional genome analysis. Papers on technological development and marine natural products should demonstrate innovation and novel applications.