Editors' ChoicePlant biology

Making Up the Meristem

Science's STKE  01 Aug 2000:
Vol. 2000, Issue 43, pp. tw6
DOI: 10.1126/stke.2000.43.tw6

The role of the CLAVATA (CLV) genes in the differentiation of the plant meristem of Arabidopsis is the focus of two reports. Trotochaud et al. investigated the interactions between CLV3, a small peptide, and CLV1, a receptor kinase. Most of the CLV3 found in vivo is complexed with CLV1. That fraction of CLV3 not bound up with CLV1 is found in a smaller multimeric complex. CLV1 similarly is found in two different complexes, only one of which includes CLV3. As with other ligand-receptor signaling systems, other components may sequester unbound ligand. Brand et al. have uncovered some of the signaling pathways that balance the supply and demand of stem cells, which provide a renewable source of replacement cells but only when needed. Stem cell accumulation is regulated by CLV3 activity, which in turn is subjected to regulatory feedback.

Trotochaud, A.E., Jeong, S., and Clark, S.E. (2000) CLAVATA3, a multimeric ligand for the CLAVATA1 receptor-kinase. Science 289: 613-617. [Abstract] [Full Text]

Brand, U., Fletcher, J.C., Hobe, M., Meyerowitz, E.M., and Simon, R. (2000) Dependence of stem cell fate in Arabidopsis on a feedback loop regulated by CLV3 activity. Science 289: 617-619. [Abstract] [Full Text]