Nuclear Photosynthetic Gene Expression Is Synergistically Modulated by Rates of Protein Synthesis in Chloroplasts and Mitochondria

authored by

Paolo Pesaresi, Simona Masiero, Holger Eubel, Hans Peter Braun, Shashi Bhushan, Elzbieta Glaser, Francesco Salamini, Dario Leister

Abstract

Arabidopsis thaliana mutants prors1-1 and -2 were identified on the basis of a decrease in effective photosystem II quantum yield. Mutations were localized to the 5′-untranslated region of the nuclear gene PROLYL-tRNA SYNTHETASE1 (PRORS1), which acts in both plastids and mitochondria. In prors1-1 and -2, PRORS1 expression is reduced, along with protein synthesis in both organelles. PRORS1 null alleles (prors1-3 and -4) result in embryo sac and embryo development arrest. In mutants with the leaky prors1-1 and -2 alleles, transcription of nuclear genes for proteins involved in photosynthetic light reactions is downregulated, whereas genes for other chloroplast proteins are upregulated. Downregulation of nuclear photosynthetic genes is not associated with a marked increase in the level of reactive oxygen species in leaves and persists in the dark, suggesting that the transcriptional response is light and photooxidative stress independent. The mrpl11 and prpl11 mutants are impaired in the mitochondrial and plastid ribosomal L11 proteins, respectively. The prpl11 mrpl11 double mutant, but neither of the single mutants, resulted in strong downregulation of nuclear photosynthetic genes, like that seen in leaky mutants for PRORS1, implying that, when organellar translation is perturbed, signals derived from both types of organelles cooperate in the regulation of nuclear photosynthetic gene expression.

Organisation(s)

Institute of Plant Genetics

External Organisation(s)

Max Planck Institute for Plant Breeding Research
Universita Degli Studi di Milano-Bicocca
Stockholm University
Ludwig-Maximilians-Universität München (LMU)
Parco Tecnologico Padano

Type

Article

Journal

PLANT CELL

Volume

18

Pages

970-991

No. of pages

22

ISSN

1040-4651

Publication date

04.2006

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Plant Science, Cell Biology

Electronic version(s)

https://doi.org/10.1105/tpc.105.039073 (Access: Open)