Fig. 5.

BV rescue of CrCHLH1 and chlorophyll accumulation in hmox1 backgrounds requires CrGUN4. (A) Comparative growth of 4A+, hmox1, gun4, hmox1gun4, and two independent genomic DNA complemented lines hmox1gun4::GUN4-STII in the dark or under constant white fluorescent light. STII, Strep-tag II. (B) Chlorophyll accumulation under different growth conditions. Exponential-phase C. reinhardtii cells were either acclimated to darkness for 24 h (dark) or grown in the dark for 12 h and then exposed to light (∼120 μmol photons m⁻² s⁻¹) for another 12 h (light). Various mutant strains were supplemented with or without 50 μM BV. Asterisks above pairs of bars indicate significant differences (Student’s t test, *P < 0.05, **P < 0.01, and ****P < 0.0001; n.s., not statistically significant). Values are means ± SD of three biological replicates.