Physiological and transcriptomic analyses reveal the effects of phytohormones on growth and astaxanthin accumulation in Haematococcus pluvialis

作者：Yang Sun, Yong Li, Jing Zhang, Rui Zhao, Jiaji Zhang, Mingxin Guo, Wenjie Yan, Xu Gao · 发表于：BMC Plant Biology · 年份：2026 · DOI：10.1186/s12870-026-08577-9 · 被引用次数：2 · 研究领域：Algal biology and biofuel production、Antioxidant Activity and Oxidative Stress、Photosynthetic Processes and Mechanisms

BACKGROUND: Haematococcus pluvialis is recognized as the richest natural source of astaxanthin, a high-value ketocarotenoid with potent antioxidant properties. Commercial production typically relies on a two-stage cultivation strategy, comprising a green vegetative phase for biomass accumulation and a red inductive phase for astaxanthin synthesis. However, a major bottleneck in this process is the balance between cell growth and pigment accumulation, as the stress conditions required for astaxanthin synthesis often inhibit biomass productivity. Phytohormones are critical signaling molecules that regulate growth and metabolism in photosynthetic organisms. Exploring their potential to decouple these conflicting physiological processes is crucial for optimizing industrial astaxanthin production. RESULTS: In this study, physiological and transcriptomic analyses were performed to evaluate the effects of five phytohormones (IAA, ABA, MeJA, ZT, and IPR) on H. pluvialis during its two-stage cultivation. Physiological data indicated distinct hormonal requirements for each stage: 0.01 mg L⁻¹ IAA significantly enhanced biomass in the green stage (0.37 g L⁻¹ vs. 0.29 g L⁻¹ in control), whereas 0.1 mg L⁻¹ MeJA maximized astaxanthin content in the red stage (29.22 mg g⁻¹ vs. 23.09 mg g⁻¹ in control). Transcriptomic profiling revealed that IAA treatment was associated with higher biomass and accompanied by increased expression of genes involved in primary carbon metabolism (PPDK), cell cycl...