The complexity of the plastid transcriptional apparatus (two or three different RNA polymerases and numerous regulatory proteins) makes it very difficult to attribute specific function(s) to its individual components. We have characterized an Arabidopsis T-DNA insertion line disrupting the nuclear gene coding for one of the six plastid sigma factors (SIG4) that regulate the activity of the plastid-encoded RNA polymerase PEP. This mutant shows a specific diminution of transcription of the plastid ndhF gene, coding for a subunit of the plastid NDH [NAD(P)H dehydrogenase] complex. The absence of another NDH subunit, i.e. NDHH, and the absence of a chlorophyll fluorescence transient previously attributed to the activity of the plastid NDH complex indicate a strong down-regulation of NDH activity in the mutant plants. Results suggest that plastid NDH activity is regulated on the transcriptional level by an ndhF-specific plastid sigma factor, SIG4.
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http://dx.doi.org/10.1093/nar/gki908 | DOI Listing |
Mol Phylogenet Evol
November 2024
Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; State Key Laboratory of Protein and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing, China.
Physiol Plant
February 2024
Plant Sciences Institute, Volcani Agricultural Research Organization (ARO), Bet Dagan, Israel.
In plants, the contribution of the plasmotype (mitochondria and chloroplast) in controlling the circadian clock plasticity and possible consequences on cytonuclear genetic makeup have yet to be fully elucidated. A genome-wide association study in the wild barley (Hordeum vulgare ssp. spontaneum) B1K collection identified overlap with our previously mapped DRIVERS OF CLOCKS (DOCs) loci in wild-cultivated interspecific population.
View Article and Find Full Text PDFInt J Mol Sci
January 2024
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, Moscow 127276, Russia.
Plastid-encoded RNA polymerase (PEP) forms a multisubunit complex in operating chloroplasts, where PEP subunits and a sigma factor are tightly associated with 12 additional nuclear-encoded proteins. Mutants with disrupted genes encoding PEP-associated proteins (PAPs) provide unique tools for deciphering mutual relationships among phytohormones. A block of chloroplast biogenesis in mutants specifying highly altered metabolism in white tissues induced dramatic fluctuations in the content of major phytohormones and their metabolic genes, whereas hormone signaling circuits mostly remained functional.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2023
Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
Nat Commun
December 2022
Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, 92521, CA, USA.
Light initiates chloroplast biogenesis in Arabidopsis by eliminating PHYTOCHROME-INTERACTING transcription FACTORs (PIFs), which in turn de-represses nuclear photosynthesis genes, and synchronously, generates a nucleus-to-plastid (anterograde) signal that activates the plastid-encoded bacterial-type RNA polymerase (PEP) to transcribe plastid photosynthesis genes. However, the identity of the anterograde signal remains frustratingly elusive. The main challenge has been the difficulty to distinguish regulators from the plethora of necessary components for plastid transcription and other essential chloroplast functions, such as photosynthesis.
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