“…Despite substantial progress in the study of the chloroplast's biology, fluorescent proteins have met limited success as reporters in the chloroplast of C. reinhardtii. Previous works have shown the use of several fluorescent proteins including GFP (Franklin et al, 2002;Noor-Mohammadi et al, 2012), mCherry (Kim et al, 2019), the Katushka yellow excitation-red emission protein that showed temporary enhanced fluorescence when chlorophyll was depleted (Suarez et al, 2022), and even the bright Vivid Verde (VFP) (Braun-Galleani et al, 2015) and Venus Q69M (Jackson et al, 2022) fluorescent proteins. However, conflicting evidence has been presented for their poor performance as an in vivo reporter, where presence of gene transcripts and protein has been shown but observation of fluorescence through microscopy has been challenging, suggesting that chlorophyll autofluorescence may impede fluorescent reporter visualization (Franklin et al, 2002;Braun-Galleani et al, 2015).…”