Atypical E2F activity coordinates PHR1 photolyase gene transcription with endoreduplication onset.
Because of their sessile life style, plants have evolved the ability to adjust to environmentally harsh conditions. An important aspect of stress adaptation involves the reprogramming of the cell cycle to ensure optimal growth. The atypical E2F transcription factor DP-E2F-like 1 (E2Fe/DEL1) had been found previously to be an important regulator of the endocycle onset. Here, a novel role for E2Fe/DEL1 was identified as a transcriptional repressor of the type-II cyclobutane pyrimidine dimer-photolyase DNA repair gene PHR1. Upon ultraviolet-B (UV-B) treatment, plants knocked out for E2Fe/DEL1 had improved DNA repair abilities when compared with control plants, whereas those overexpressing it performed less well. Better DNA repair allowed E2Fe/DEL1 knockout plants to resume endoreduplication faster than control plants, contributing in this manner to UV-B radiation resistance by compensating the stress-induced reduction in cell number by ploidy-dependent cell growth. As E2Fe/DEL1 levels decreased upon UV-B treatment, we hypothesize that the coordinated transcriptional induction of PHR1 with the endoreduplication onset contributes to the adaptation of plants exposed to UV-B stress.
Department of Plant Systems Biology, VIB, Gent, Belgium.
Amandine
A
Radziejwoski
Kobe
K
Vlieghe
Tim
T
Lammens
Barbara
B
Berckmans
Sara
S
Maes
Marcel A K
MA
Jansen
Claudia
C
Knappe
Andreas
A
Albert
Harald K
HK
Seidlitz
Günther
G
Bahnweg
Dirk
D
Inzé
Lieven
L
De Veylder
D000220:Adaptation, Biological / Q000235:genetics*; D017360:Arabidopsis / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers / Q000235:genetics; D004260:DNA Repair / Q000528:radiation effects; D004261:DNA Replication / Q000235:genetics / Q000502:physiology*; D005434:Flow Cytometry; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D055786:Gene Knockout Techniques; D016133:Polymerase Chain Reaction; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological / Q000528:radiation effects*; D013472:Sunlight / Q000009:adverse effects*; D014157:Transcription Factors / Q000378:metabolism*; D014466:Ultraviolet Rays
D029681:Arabidopsis Proteins; C500416:DEL1 protein, Arabidopsis; D017931:DNA Primers; C514695:PHR1 protein, Arabidopsis; D012097:Repressor Proteins; D014157:Transcription Factors