Oral Presentation 18th International Congress on Photobiology 2024

Translation control by the cytosolic biomolecular condensate P-bodies optimizes early seedling developments in Arabidopsis (#45)

Shu-Hsing Wu 1
  1. Institute of Plant and Microbial Biology, Academia Sinica, Nankang, TAIPEI, Taiwan

Dark-grown Arabidopsis seedlings can sequester specific mRNAs that encode proteins for photomorphogenesis in processing bodies (p-bodies) to attenuate their translation before exposure to light (Jang et al. 2019). However, how this selected sequestration is achieved and its biological impacts remain to be investigated. DCP5 (Decapping 5) is one of the p-body components with an RNA binding motif; therefore, it has the potential to bind and recruit mRNAs into p-bodies. We adopted infrared-CLIP (irCLIP) and RNA-seq to reveal direct target mRNAs of DCP5. Among the candidate mRNAs include CHL27 and TCP14CHL27encodes a protochlorophyllide biosynthetic enzyme magnesium-protoporphyrin IX monomethyl ester cyclase, and TCP14 (TEOSINTE BRANCHED, CYCLOIDEA AND PCF 14) is a transcription factor functioning in etioplast to chloroplast transition and in activating ELIP1 (Early light-induced protein 1) and ELIP2 to promote cotyledon greening efficiency. We confirmed DCP5 associates with CHL27 and TCP14 mRNAs in p-bodies via specific binding sites. Our results also showed that, in dark-grown seedlings, DCP5 functions to recruit and stall the translation of CHL27 and TCP14 mRNAs to achieve a balanced chlorophyll accumulation and chloroplast development when transitioning to the light environment. This sequestration ensures a timely and precise switch from skotomorphogenesis to photomorphogenesis development in Arabidopsis seedlings.

  1. Institute of Plant and Microbial Biology, Academia Sinica, Nankang, TAIPEI, Taiwan