Fig. 9
Agglomerative hierarchical clustering of A 41 photosynthesis-related differentially expressed genes (DEGs). B Sixty-eight respiration-related DEGs; C 18 photorespiration-related DEGs; D 17 antioxidant system-related DEGs in Ulva prolifera after the 1st day of 1 W/m2 ultraviolet-B (UVB) (1-1d), after the 4th day 1 W/m2 UVB (1-4d), after the 1st day of 5 W/m2 UVB (5-1d) compared with the control. In the figure, 0-1d indicates after the 1st day of 72 μmol m−2 s−1 photosynthetically active radiation (PAR); 0-4d indicates after the 4th day of 72 μmol m−2 s.−1 PAR. The color range from blue to red indicates the degree of enrichment from low to high, respectively. Statistical significance is indicated by * (P < 0.05), **(P < 0.01), and ****(P < 0.001)