Fig. 1

Growth and photosynthetic parameters of P. tricornutum during the two-stage treatment. A Schematic illustration of the two-stage treatment. B Heatmap shows the log2(fold change) values of cell number, dry weight, Fv/Fm, NPQ, Y(II), Y(NPQ), Y(NO), and ROS during stage I (HL versus CT) and stage II (HLR versus HLC). C Cell number, dry weight, Fv/Fm, NPQ, Y(II), Y(NPQ), and Y(NO) of day 3 cultures for CT, HL, HLC and HLR. The significant difference is designated by * (p < 0.05) or ** (p < 0.01) under Student’s t-test