The histone acetyltransferases (HATs), together with histone deacetylases, regulate the gene transcription related to various biological processes, including stress responses in eukaryotes. This study found a member of HATs (HpGCN5) from a transcriptome of the economically important microalgae Haematococcus pluvialis. Its expression pattern responding to multiple abiotic stresses and its correlation with transcription factors and genes involved in triacylglycerols and astaxanthin biosynthesis under stress conditions were evaluated, aiming to discover its potential biological function. The isolated HpGCN5 was 1,712 bp in length encoding 415 amino acids. The signature domains of Acetyltransf_1 and BROMO were presented, as the GCN5 gene from Arabidopsis and Saccharomyces cerevisiae, confirming that HpGCN5 belongs to the GCN5 subfamily of the GNAT superfamily. The phylogenetic analysis revealed that HpGCN5 is grouped with GNAT genes from algae and is closer to that from higher plants, compared with yeast, animal, fungus, and bacteria. It was predicted that HpGCN5 is composed of 10 exons and contains multiple stress-related cis-elements in the promoter region, revealing its potential role in stress regulation. Real-time quantitative PCR revealed that HpGCN5 responds to high light and high salt stresses in similar behavior, evidenced by their down-regulation exposing to stresses. Differently, HpGCN5 expression was significantly induced by SA and Nitrogen-depletion stresses at the early stage but was dropped back after then. The correlation network analysis suggested that HpGCN5 has a strong correlation with major genes and a transcription factor involved in astaxanthin biosynthesis. Besides, the correlation was only found between HpGCN5 and a few genes involved in triacylglycerols biosynthesis. Therefore, this study proposed that HpGCN5 might play a role in the regulation of astaxanthin biosynthesis. This study firstly examined the role of HATs in stress regulation and results will enrich our understanding of the role of HATs in microalgae.

组蛋白乙酰转移酶 (HAT) 与组蛋白脱乙酰酶一起调节与各种生物过程相关的基因转录，包括真核生物中的应激反应。这项研究发现了一个 HAT 成员 (HpGCN5) 来自具有重要经济意义的微藻的转录组雨生红球菌. 对其响应多种非生物胁迫的表达模式及其与转录因子和基因的相关性进行了评估，这些转录因子和基因在胁迫条件下参与三酰基甘油和虾青素的生物合成，旨在发现其潜在的生物学功能。孤立的HpGCN5长度为 1,712 bp，编码 415 个氨基酸。Acetyltransf_1 和 BROMO 的特征结构域作为 GCN5 基因来自拟南芥和酿酒酵母, 确认HpGCN5属于 GNAT 超家族的 GCN5 亚家族。系统发育分析表明，HpGCN5与酵母、动物、真菌和细菌相比，它与来自藻类的 GNAT 基因分组，更接近来自高等植物的基因。据预测，HpGCN5由 10 个外显子组成，包含多个应力相关顺式-启动子区域中的元素，揭示了其在应激调节中的潜在作用。实时定量 PCR 显示，HpGCN5以相似的行为对高光和高盐胁迫做出反应，这可以通过它们在胁迫下的下调来证明。不同的是，HpGCN5SA和氮耗尽胁迫在早期显着诱导表达，但之后又下降。相关网络分析表明HpGCN5与主要基因和参与虾青素生物合成的转录因子有很强的相关性。此外，相关性仅在HpGCN5和一些参与甘油三酯生物合成的基因。因此，本研究提出HpGCN5可能在虾青素生物合成的调节中发挥作用。本研究首先考察了 HATs 在应激调节中的作用，结果将丰富我们对 HATs 在微藻中的作用的理解。