Transcriptomic and metabolic analysis of an astaxanthin-hyperproducing Haematococcus pluvialis mutant obtained by low-temperature plasma (LTP) mutagenesis under high light irradiation
Transcriptomic and metabolic analysis of an astaxanthin-hyperproducing Haematococcus pluvialis mutant obtained by low-temperature plasma (LTP) mutagenesis under high light irradiation
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高产虾青素雨生红球藻突变体的转录组和代谢分析，该突变体通过强光照射下的低温等离子体（LTP）诱变获得
DOI：
10.1016/j.algal.2019.101746
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发表时间：
2020-01-01
影响因子：
5.1
通讯作者：
Huang, Qing
中科院分区：
文献类型：
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作者：
Chen, Zhu;Chen, Jun;Huang, Qing
雨生红球藻在各种逆境条件下都能积累足够的虾青素。强光照对雨生红球藻中虾青素的积累至关重要。然而，由于缺乏基因组信息，限制了对其高虾青素产量的生理代谢的理解。本研究对野生型菌株和突变株（M3）在强光照射下的生物合成进行了比较。收集并分析了雨生红球藻在强光胁迫下24 h的从头转录组信息。我们的转录组学结果表明，M3菌株通过增加磷酸烯醇式丙酮酸羧化酶（PEPC）、苹果酸脱氢酶（MDH）、苹果酸脱氢酶（ME）的表达水平，核酮糖二磷酸羧化酶/加氧酶（Rubisco）活化酶（RCA）和甘油醛3-磷酸脱氢酶（GAPDH）而降低果糖-1，6-二磷酸酶（FBP）的表达水平。色素分析、叶绿素荧光分析和实时荧光定量PCR（qRT-PCR）分析表明，M3菌株通过调节氯呼吸途径，提高非光合色素（叶黄素、β-胡萝卜素和虾青素）含量，减轻光氧化损伤，从而维持较高的光合活性。此外，M3菌株显示出比WT菌株更高的脂肪酸含量。总体而言，从头转录组学和生理数据的组合分析提供了必要的信息，不仅可以更好地了解WT和M3菌株之间的虾青素生物合成的差异，而且在未来的雨生红球藻基因工程的可行性。
Haematococcus pluvialis can accumulate sufficient levels of astaxanthin under various stress conditions. High light irradiation is essential for astaxanthin accumulation in Haematococcus pluvialis. However, a lack of genomic information limits the understanding of its physiological metabolism for high astaxanthin production. In this work, we investigated the wild-type (WT) strain and mutant strain (named as M3 which was obtained in our previous work) under high light irradiation and compared the difference in astaxanthin biosynthesis. We collected and analyzed the data of de novo transcriptome information of Haematococcus pluvialis at 24 h under high light stress. Our transcriptomic results indicated that M3 strain had higher utilization efficiency of CO2 to provide the precursors of carotenoid and fatty acid biosynthesis by increasing the expression levels of phosphoenolpyruvate carboxylase (PEPC), malate dehydrogenase (MDH), malate dehydrogenase (ME), ribulose bisphosphate carboxylase/oxygenase (Rubisco) activase (RCA) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) while decreasing the expression levels of fructose-1, 6-bisphosphatase (FBP). The analysis of pigments, chlorophyll fluorescence and the quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that M3 strain maintained higher photosynthetic activity by regulating chlororespiration pathway and elevating non-photosynthetic pigment (lutein, beta-carotene, and astaxanthin) content to alleviate photooxidative damage. Moreover, the M3 strain showed higher fatty acid content than the WT strain. Overall, combinative analysis of de novo transcriptomic and physiological data provided information necessary for not only a better understanding of the difference in astaxanthin biosynthesis between WT and M3 strains but also the feasibility of genetic engineering of Haematococcus pluvialis in the future.