SOG1 LINKS THE DNA DAMAGE RESPONSE TO ORGAN REGENERATION
Johnson, R.J.1, Conklin, P.A.1, Tjahjadi, M.1, Shi, F.1, Missirian, V.1, Toal, T.1, Brady, S.M.1 and Britt, A.B.1
1Department of Plant Biology, University of California, Davis, USA
Contact: Ross Johnson, DrRJohnson@UCDavis.edu
In Arabidopsis, DNA damage-induced programmed cell death is limited to the meristematic stem cell niche. The significance of this cell-type specific programmed cell death is unclear. Here we demonstrate in roots that it is the programmed destruction of the mitotically-compromised stem cell niche that triggers its regeneration, enabling growth recovery. In contrast to wild-type plants, sog1 plants, which are defective in damage-induced programmed cell death, maintain their cell identities and stereotypical structure of the stem cell niche, but these cells fail to undergo cell division, terminating root growth. We propose DNA damage-induced programmed cell death is employed by plants as a developmental response, contrasting with its role as an anti-carcinogenic response in animals. This role in plants may have evolved to restore embryonic root growth after the accumulation of DNA damage in seeds.