Tetradesmus obliquus Raw sequence reads. Tetradesmus obliquus

Daphnia cultivation water containing predation cues was added in algal cultures to induce the colony formation of Scenedesmus obliquus. In brief, D. magna feeding S. obliquus with 106 cells mL-1 was incubated at a density of 300 individuals per liter for 24 h. The cultivation water was then filtered through a 0.22 μm membrane filter (Millipore Corporation, USA) to obtain the Daphnia filtrate. Another suspension of S. obliquus that was not exposed to D. magna was filtered in the same way to obtain the control filtrate. Nitrogen and phosphate levels in the Daphnia filtrate and the control filtrate were then adjusted to the levels in the BG–11 recipe. While the exponentially growing S. obliquus cells were transferred in 1 L flasks containing 450 mL BG–11 media and either 50 mL Daphnia filtrate (grazing group) or 50 mL control filtrate (control group). The initial algal abundance was approximately 5×104 cells mL-1. Three and eight replicates were set up respectively for the transcriptomic and metabolomic studies. Sampling was performed while the morphological changes reached the peak (4th day after the addition of Daphnia filtrate). All the flasks were incubated at the same conditions described above. The number of cells in different morphs (unicell, two-, four- and eight-celled colonies and others) were determined daily by counting at least 100 particles. The average cells per particle were calculated based on the above counts. Volumes of 10 mL algal suspension were taken for the polysaccharides analysis.