Characterization of the wild type, Δnd4, pgrl1, and Δnd4pgrl1 growth under strong illumination. Impact of chloroplastic and mitochondrial mutation on growth of C. reinhardtii strains is assessed by spot test (A), i.e. cells plated in different dilutions on solid media in mixotrophic (TAP) or photoautotrophic (TMP) conditions for wild type, pgrl1, Δnd4, and Δnd4pgrl1 mutant strains. The cells were grown at HL intensity of 850 μE m−2 s−1. Photos were taken after 3 to 5 d. Impact of mutation was also assessed in liquid culture (B) in photoautotrophic conditions (TMP) for wild type, pgrl1, Δnd4, and Δnd4pgrl1 at a HL intensity of 1,500 μE m−2 s−1. Error bars indicate sd (n = 3–6 independent biological replicates). Statistically significant differences compared to the wild type are indicated with an asterisk. Two asterisks instead indicate significant differences with both the wild type and Δnd4pgrl1.