The objective of this study is to characterize effects of autophagy inhibition by 3-methyladenine on astaxanthin and fatty acid accumulation in Haematococcus pluvialis cultivated under high light condition. The present data show that 0.02 mM 3-methyladenine treatment effectively inhibited autophagosome formation but no impact on the cell growth and biomass of H. pluvialis, leading to a large increase in cellular reactive oxygen species (ROS), astaxanthin and fatty acid accumulation as well as palmitic acid enrichment under high light of 700 μmol·m⁻²·s⁻¹. Furthermore, the key genes such as phytoene synthase (PSY), β-carotene ketolase (CRTO), and β-carotene hydroxylase (CRTR-b) in astaxanthin pathway are upregulated significantly whereas the expressions of the lipid-related genes biotin carboxylase (BC) and diacylglycerol acyltransferase (HpDGAT2D) just increased slightly in the 3-methyladenine-treated cells. Astaxanthin accumulation is not perfectly linear with fatty acid biosynthesis in H. pluvialis treated by 3-methyladenine under high light. Overall, autophagy might function importantly in astaxanthin and lipid enrichment in H. pluvialis under stress condition. The findings provide new insights to further investigation on the metabolic regulation in microalgae.

这项研究的目的是表征3-甲基腺嘌呤对在强光条件下培养的雨生红球菌虾青素和脂肪酸积累的自噬抑制作用。本数据显示，0.02毫3-甲基腺嘌呤治疗有效地抑制自噬体形成，但对细胞生长和生物量没有影响H.生红球藻，导致在细胞内活性氧的大量增加（ROS），虾青素和脂肪酸积累以及在700μmol·m ^-2 ·s ^-1的高光下，棕榈酸富集。此外，关键基因包括八氢番茄红素合酶（PSY），β-胡萝卜素酮醇酶（CRTO）），虾青素途径中的β-胡萝卜素羟化酶（CRTR-b）显着上调，而脂质相关基因生物素羧化酶（BC）和二酰基甘油酰基转移酶（HpDGAT2D）的表达在3-甲基腺嘌呤处理的细胞中仅略有增加。虾青素积累不是完美的线性与脂肪酸生物合成H.生红球藻用在高光3-甲基腺嘌呤处理。总体而言，自噬可能在应激条件下对虾青霉菌中虾青素和脂质富集起重要作用。这些发现为进一步研究微藻的代谢调控提供了新的见解。