Deconvoluting apocarotenoid‐mediated retrograde signaling networks regulating plastid translation and leaf development

Signals originating within plastids modulate organelle differentiation by transcriptionally regulating nuclear-encoded genes. These retrograde signals are also integral regulators of plant development, including leaf morphology. The clb5 mutant displays severe morphology defects due to Apocarotenoid Signal 1 (ACS1) accumulation in the developmentally arrested plastid. Transcriptomic analysis validates that ACS1 deregulates hundreds nuclear genes, suppression most genes encoding plastid ribosomal proteins. Herein, we order molecular events causing phenotype associated with ACS1, which includes two consecutive signaling cascades. Firstly, drives inhibition translation (IPT) via transcriptome remodeling chlororibosomal proteins, requiring light as an essential component. Subsequently, IPT results morphological a GUN1-dependent pathway shared seedlings undergoing chemical treatments and is restricted early window development. Collectively, this work advances our understanding complexity exemplified sequential signal exchange consequences particular temporal spatial context contribute modulation