Constancy of organellar genome copy numbers during leaf development and senescence in higher plants

  • Li W
  • Ruf S
  • Bock R
  • 30


    Mendeley users who have this article in their library.
  • 37


    Citations of this article.


In higher plants, plastid and mitochondrial genomes occur at high copy numbers per cell. Several recent publications have suggested that, in higher plants like Arabidopsis and maize, chloroplast DNA is virtually absent in mature and old leaves. This conclusion was mainly based on DAPI staining of isolated chloroplasts. If correct, the finding that chloroplasts in mature leaves lack DNA would change dramatically our understanding of gene expression, mRNA stability and protein stability in chloroplasts. In view of the wide implications that the disposal of chloroplast DNA during leaf development would have, we have reinvestigated the age dependency of genome copy numbers in chloroplasts and, in addition, tested for possible changes in mitochondrial genome copy number during plant development. Analyzing chloroplast and mitochondrial DNA amounts in Arabidopsis and tobacco plants, we find that organellar genome copy numbers remain remarkably constant during leaf development and are present in essentially unchanged numbers even in the senescing leaves. We conclude that, during leaf development, organellar gene expression in higher plants is not significantly regulated at the level of genome copy number and we discuss possible explanations for the failure to detect DNA in isolated chloroplasts stained with DAPI.

Author-supplied keywords

  • Arabidopsis thaliana
  • Genome copy number
  • Leaf development
  • Mitochondrion
  • Nicotiana tabacum
  • Plastid

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Weimin Li

  • Stephanie Ruf

  • Ralph Bock

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free