Differential expression of desaturase genes and changes in fatty acid composition of Mortierella sp. AGED in response to environmental factors.
Differential expression of desaturase genes and changes in fatty acid composition of Mortierella sp. AGED in response to environmental factors.
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DOI：
10.1002/jsfa.7990
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发表时间：
2017-04
影响因子：
4.1
通讯作者：
Li Tan;Rui Zhuo;Shue Li;Fuying Ma;Xiaoyu Zhang
中科院分区：
文献类型：
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作者：
Li Tan;Rui Zhuo;Shue Li;Fuying Ma;Xiaoyu Zhang
一些产油真菌可以产生大量具有多种生理功能的多不饱和脂肪酸（PUFAs）。许多去饱和酶对PUFAs的合成至关重要。本研究旨在探讨Mortierella sp. age对不同环境因素对脂质产生和去饱和酶基因表达的调控，以及脂质产生与去饱和酶基因表达的关系。结果低温条件下，脂肪酸组成和去饱和酶基因mRNA水平发生显著变化。除Δ5-desaturase外，在20°C温度下，所有去饱和酶基因的转录物水平均升高。脂质和PUFAs含量在低温下的变化与去饱和酶基因的表达一致。基因表达的时间过程研究表明，低温处理后4种去饱和酶基因的mRNA水平迅速升高。1.5% v/v的乙醇显著提高了Δ9-、Δ6-和Δ5-desaturase基因的转录本水平，略微提高了Δ12-desaturase基因的转录本水平。Ca2+、Zn2+、Fe3+等不同金属离子均能刺激PUFA合成，上调去饱和酶基因转录，Cu2+抑制去饱和酶基因表达和脂质积累。结论本研究有助于我们进一步了解去饱和酶基因表达和脂质合成的调控机制。这有助于提高Mortierella sp. AGED的PUFA产率。©2016化学工业协会。
BACKGROUND Some oleaginous fungi can produce large amounts of polyunsaturated fatty acids (PUFAs) which serve many physiological functions. Numerous desaturases are critical for the synthesis of PUFAs. This study aimed to investigate the regulation of lipid production and desaturase gene expression in Mortierella sp. AGED in response to different environmental factors, and the relationships between lipid production and desaturase gene expression. RESULTS The fatty acid composition and mRNA levels of desaturase genes were significantly changed under low temperatures. With the exception of Δ5-desaturase, the transcript levels of all desaturase genes increased at a temperature of 20 °C. Changes in content of lipid and PUFAs responding to low temperature were consistent with desaturase gene expression. Time course studies on gene expression showed that mRNA levels of four desaturase genes increased rapidly after transferring the cells to low temperature. Ethanol (1.5% v/v) increased the transcript levels of Δ9-, Δ6- and Δ5-desaturase genes significantly and of Δ12-desaturase gene slightly. Different metal ions such as Ca2+ , Zn2+ and Fe3+ could stimulate PUFA synthesis and up-regulate desaturase gene transcription, while Cu2+ inhibited desaturase gene expression and lipid accumulation. CONCLUSION This study should enable us to understand the regulatory mechanism of desaturase gene expression and lipid synthesis. It is helpful to improve PUFA productivity in Mortierella sp. AGED. © 2016 Society of Chemical Industry.