Streamlined regulation of chloroplast development in the liverwort Marchantia polymorpha
Nataliya E. Yelina, Eftychios Frangedakis, Zhemin Wang, Tina B. Schreier, Jenna Rever, Marta Tomaselli, Edith Forestier, Kumari Billakurthi, Sibo Ren, Yahui Bai, Julia Stewart-Wood, Jim Haseloff, Silin Zhong, Julian M. Hibberd
Abstract
Chloroplasts develop from undifferentiated plastids in response to light. In angiosperms, after the perception of light, the Elongated Hypocotyl 5 (HY5) transcription factor initiates photomorphogenesis, and two families of transcription factors known as GOLDEN2-LIKE (GLK) and GATA are considered master regulators of chloroplast development. In addition, the MIR171-targeted SCARECROW-LIKE GRAS transcription factors also impact chlorophyll biosynthesis. The extent to which these proteins carry out conserved roles in non-seed plants is not known. Using the model liverwort Marchantia polymorpha, we show that GLK controls chloroplast biogenesis, and HY5 shows a small conditional effect on chlorophyll content. Chromatin immunoprecipitation sequencing (ChIP-seq) revealed that MpGLK has a broader set of targets than has been reported in angiosperms. We also identified a functional GLK homolog in green algae. In summary, our data support the hypothesis that GLK carries out a conserved role relating to chloroplast biogenesis in land plants and green algae.