Cells (Jun 2019)

Mitochondrial Transcriptome Control and Intercompartment Cross-Talk During Plant Development

  • Adnan Khan Niazi,
  • Etienne Delannoy,
  • Rana Khalid Iqbal,
  • Daria Mileshina,
  • Romain Val,
  • Marta Gabryelska,
  • Eliza Wyszko,
  • Ludivine Soubigou-Taconnat,
  • Maciej Szymanski,
  • Jan Barciszewski,
  • Frédérique Weber-Lotfi,
  • José Manuel Gualberto,
  • André Dietrich

DOI
https://doi.org/10.3390/cells8060583
Journal volume & issue
Vol. 8, no. 6
p. 583

Abstract

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We address here organellar genetic regulation and intercompartment genome coordination. We developed earlier a strategy relying on a tRNA-like shuttle to mediate import of nuclear transgene-encoded custom RNAs into mitochondria in plants. In the present work, we used this strategy to drive trans-cleaving hammerhead ribozymes into the organelles, to knock down specific mitochondrial RNAs and analyze the regulatory impact. In a similar approach, the tRNA mimic was used to import into mitochondria in Arabidopsis thaliana the orf77, an RNA associated with cytoplasmic male sterility in maize and possessing sequence identities with the atp9 mitochondrial RNA. In both cases, inducible expression of the transgenes allowed to characterise early regulation and signaling responses triggered by these respective manipulations of the organellar transcriptome. The results imply that the mitochondrial transcriptome is tightly controlled by a “buffering” mechanism at the early and intermediate stages of plant development, a control that is released at later stages. On the other hand, high throughput analyses showed that knocking down a specific mitochondrial mRNA triggered a retrograde signaling and an anterograde nuclear transcriptome response involving a series of transcription factor genes and small RNAs. Our results strongly support transcriptome coordination mechanisms within the organelles and between the organelles and the nucleus.

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