Living with genome instability: Plant responses to telomere dysfunction

Loss of telomere function in metazoans results in catastrophic damage to th e genome, cell cycle arrest, and apoptosis, Here we show that the mustard w eed Arabidopsis thaliana can survive up to 10 generations without telomeras e. The Last five generations of telomerase-deficient plants endured increas ing Levels of cytogenetic damage, which was correlated with developmental a nomalies in both vegetative and reproductive organs. Mutants ultimately arr ested at a terminal vegetative state harboring shoot meristems that were gr ossly enlarged, disorganized, and in some cases, dedifferentiated into a ca llusoid mass. Unexpectedly, Late-generation mutants had an extended Life-sp an and remained metabolically active. The differences in plant and animal r esponses to dysfunctional telomeres may reflect the more plastic nature of plant development and genome organization.