Senescing cells share common features with dedifferentiating cells.
Dedifferentiation signifies the capacity of somatic cells to acquire stem cell-like properties. This process can be induced during normal development and as a response to various stimuli, such as pathogen infection and wounding. Dedifferentiation also characterizes the transition of differentiated leaf cells into protoplasts (plant cells devoid of cell walls), a transition accompanied by widespread chromatin decondensation. Transcriptome profiling of dedifferentiating protoplast cells revealed striking similarities with senescing cells; both display a large increase in the expression of genes of specific transcription factor (TF) families, including ANAC, WRKY, bZIP, and C2H2. Further analysis showed that leaves induced to senesce by exposure to dark display characteristic features of dedifferentiating cells, including chromatin decondensation, disruption of the nucleolus, and condensation of rRNA genes. Considering that premature senescence can be induced by various stress conditions both in plant and animal cells, our results suggest that the response of plant and also animal cells to certain stresses converges on cellular dedifferentiation whereby cells first acquire stem cell-like state prior to acquisition of a new cell fate (e.g., reentry into the cell cycle or death).
Damri
Meytal
M
French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel and Midreshet Ben-Gurion, Israel.
Granot
Gila
G
Ben-Meir
Hagit
H
Avivi
Yigal
Y
Plaschkes
Inbar
I
Chalifa-Caspi
Vered
V
Wolfson
Marina
M
Fraifeld
Vadim
V
Grafi
Gideon
G
D017360:Arabidopsis / Q000166:cytology* / Q000201:enzymology / Q000235:genetics; D054337:Cell Dedifferentiation / Q000502:physiology*; D002466:Cell Nucleolus / Q000378:metabolism; D016922:Cellular Senescence / Q000502:physiology*; D004275:DNA, Ribosomal / Q000235:genetics; D003624:Darkness; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D011523:Protoplasts / Q000166:cytology / Q000201:enzymology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D004275:DNA, Ribosomal; D014157:Transcription Factors; D020928:Mitogen-Activated Protein Kinases