Plant biology

Differential Aging

Science Signaling  24 Feb 2009:
Vol. 2, Issue 59, pp. ec74
DOI: 10.1126/scisignal.259ec74

On one plant, leaves may age at different rates. Kim et al. have analyzed the molecular signals that govern aging of leaves in Arabidopsis and found that mutations in a handful of genes slowed the normal process by which the leaves aged. One gene encodes a transcription factor previously known for its response to saline conditions. The transcript of this gene is a target for microRNA, miR164. As the amount of miR164 decreases with age (a decline that is regulated by yet another gene captured in this screen), the gene encoding the transcription factor activates cell death processes, which ultimately results in the death of the entire leaf.

J. H. Kim, H. R. Woo, J. Kim, P. O. Lim, I. C. Lee, S. H. Choi, D. Hwang, H. G. Nam, Trifurcate feed-forward regulation of age-dependent cell death involving miR164 in Arabidopsis. Science 323, 1053–1057 (2009). [Abstract] [Full Text]