Transcriptome analysis reveals pathways responsible for the promoting effect of sucrose on astaxanthin accumulation in Haematococcus pluvialis under high light condition
Transcriptome analysis reveals pathways responsible for the promoting effect of sucrose on astaxanthin accumulation in Haematococcus pluvialis under high light condition
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转录组分析揭示了强光条件下蔗糖促进雨生红球藻虾青素积累的途径
DOI：
10.1016/j.aquaculture.2020.735757
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发表时间：
2021-01-15
期刊：
影响因子：
4.5
通讯作者：
Xu, Nianjun
中科院分区：
文献类型：
--
作者：
Du, Feichao;Hu, Chaoyang;Xu, Nianjun
雨生红球藻在胁迫条件下积累了大量的虾青素，这是一种具有超强抗氧化活性的宝贵的酮类胡萝卜素。提供合适的碳源已被证明是促进雨生红藻虾青素积累的有效方法，但其机制尚不清楚。在此，我们证明了在强光胁迫下，添加蔗糖(1-10 mM)可使雨生红藻的虾青素产量提高27.9-34.2%。随后，比较转录分析揭示了蔗糖促进虾青素生物合成的机制。蔗糖处理显著上调了许多编码蔗糖和淀粉代谢、糖酵解、虾青素生物合成和脂肪酸代谢的基因的表达。此外，蔗糖处理显著改变了29个转录因子的表达，这些转录因子是蔗糖代谢、脂类生物合成和虾青素生物合成的潜在关键调控因子。此外，外源添加蔗糖分解代谢和糖酵解途径的代谢产物(葡萄糖-6-磷酸二钠和果糖-1，6-二磷酸三钠)显著提高了虾青素的产量，分别提高了33.1%和18.1%。结果表明，蔗糖处理对雨生红豆杉的转录本有显著影响，在强光条件下，有利于红豆杉从碳代谢向虾青素积累转变。
Haematococcus pluvialis accumulates large amount of astaxanthin, a valuable ketocarotenoid with super antioxidant activity, under stress conditions. Providing suitable carbon source has been proved to be an effective method to promote astaxanthin accumulation in H. pluvialis, however, mechanisms remain obscure. Here, we demonstrate that adding sucrose (1-10 mM) into the culture media increase astaxanthin yield by 27.9-34.2% in H. pluvialis under high light stress. Subsequently, comparative transcriptomic analysis revealed the mechanism underling the promoting effect of sucrose on astaxanthin biosynthesis. Sucrose treatment significantly upregulated the expression of many enzyme encoding genes involved in sucrose and starch metabolism, glycolysis, astaxanthin biosynthesis, and fatty acids metabolism. In addition, sucrose treatment significantly changed the expression of 29 transcriptional factors, potential key regulators in sucrose metabolism, lipid biosynthesis and astaxanthin biosynthesis. Furthermore, exogenous application of metabolites involved in sucrose catabolism and glycolysis pathway (glucose-6-phosphate disodium and fructose-1,6-diphosphate trisodium) significantly promoted astaxanthin yield by 33.1% and 18.1%, respectively. Our results indicated that sucrose treatment exerts remarkable effects on the transcriptomes of H. pluvialis, favoring the shift from carbon metabolism to astaxanthin accumulation under high light condition.