Transcriptomic choreography in response to light quality variation reveals metabolic acclimation in marine Nannochloropsis oceanica.

We report the transcriptomic dynamics and metabolic adaptation of Nannochloropsis oceanica to blue (410nm) and red (680nm) light by high-throghout Next-generation sequencing (NGS). Preferential excitation of different light spectra induces massive reprogramming of the Nannochloropsis transcriptome. Nannochloropsis oceanica IMET1 was inoculated into modified f/2 liquid medium containing 30 g/L sea salt, 10 mM Tris-HCl (pH 7.6), 427.5 mg/L NaNO3, 30 mg/L NaH2PO4·H2O, 5 mg/L trace metal mixture (4.36 g/L Na2EDTA·2H2O, 3.15 g/L FeCl3·6H2O, 10 mg/L CoCl2·6H2O, 22 mg/L ZnSO4·7H2O, 180 mg/L MnCl2·4H2O, 9.8 mg/L CuSO4·5H2O, 6.3 mg/L Na2MoO4·2H2O), and 2.5 mg/L vitamin stock solution (1 mg/L vitamin B12, 1 mg/L biotin, 200 mg/L thiamine). The cells were cultivated in liquid cultures using column bioreactor under continuous light (approximately 80 ± 5 µmol photons m-2 s-1) at 25˚C and aerated by bubbling with air-level CO2 (0.04%) at 0.6 vvm (volume gas per volume medium per minute) under white, red and blue light..After the switch from white light to red and blue light, cell aliquots were taken at 0 (white light), 12 (red and blue light), and 24h (red and blue light) from each column by syringe for transcriptomic profiling.

本研究通过高通量下一代测序（Next-generation sequencing, NGS）技术，解析了海洋微拟球藻（Nannochloropsis oceanica）对蓝光（410nm）与红光（680nm）的转录组动态变化及代谢适应特征。不同光谱的选择性激发可引发海洋微拟球藻转录组的大规模重编程。将海洋微拟球藻IMET1接种至改良f/2液体培养基中，该培养基含30 g/L海盐、10 mM Tris-HCl（pH 7.6）、427.5 mg/L硝酸钠、30 mg/L一水合磷酸二氢钠、5 mg/L微量元素混合液（成分为：4.36 g/L二水合乙二胺四乙酸二钠、3.15 g/L六水合氯化铁、10 mg/L六水合氯化钴、22 mg/L七水合硫酸锌、180 mg/L四水合氯化锰、9.8 mg/L五水合硫酸铜、6.3 mg/L二水合钼酸钠），以及2.5 mg/L维生素储备液（成分为：1 mg/L维生素B12、1 mg/L生物素、200 mg/L硫胺素）。采用柱式生物反应器进行液体培养，培养条件为：连续光照（光强约80 ± 5 µmol·m⁻²·s⁻¹）、培养温度25℃，分别在白光、红光及蓝光条件下，以0.6 vvm（每分钟每单位体积培养基通入的气体体积）的流速通入含0.04% CO₂的空气进行曝气。将培养体系从白光切换为红光与蓝光后，分别于0 h（白光条件下）、12 h（红光/蓝光条件下）及24 h（红光/蓝光条件下）通过注射器从各柱式反应器中抽取细胞等分试样，用于转录组分析。