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GENOMES UNCOUPLED1 plays a key role during the de‐etiolation process in Arabidopsis
Author(s) -
HernándezVerdeja Tamara,
Vuorijoki Linda,
Jin Xu,
Vergara Alexander,
Dubreuil Carole,
Strand Åsa
Publication year - 2022
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.18115
Subject(s) - photomorphogenesis , arabidopsis , plastid , biology , chloroplast , seedling , etiolation , nuclear gene , darkness , genome , retrograde signaling , microbiology and biotechnology , gene , photosynthesis , transcription factor , botany , genetics , mutant , biochemistry , enzyme
Summary One of the most dramatic challenges in the life of a plant occurs when the seedling emerges from the soil and exposure to light triggers expression of genes required for establishment of photosynthesis. This process needs to be tightly regulated, as premature accumulation of light‐harvesting proteins and photoreactive Chl precursors causes oxidative damage when the seedling is first exposed to light. Photosynthesis genes are encoded by both nuclear and plastid genomes, and to establish the required level of control, plastid‐to‐nucleus (retrograde) signalling is necessary to ensure correct gene expression. We herein show that a negative GENOMES UNCOUPLED1 (GUN1)‐mediated retrograde signal restricts chloroplast development in darkness and during early light response by regulating the transcription of several critical transcription factors linked to light response, photomorphogenesis, and chloroplast development, and consequently their downstream target genes in Arabidopsis. Thus, the plastids play an essential role during skotomorphogenesis and the early light response, and GUN1 acts as a safeguard during the critical step of seedling emergence from darkness.