Nature 449, 1053-1057 (25 October 2007) | doi:10.1038/nature06206; Received 5 July 2007; Accepted 30 August 2007
PLETHORA proteins as dose-dependent master regulators of Arabidopsis root development
Carla Galinha1,2,3, Hugo Hofhuis1,2, Marijn Luijten1, Viola Willemsen1, Ikram Blilou1, Renze Heidstra1 & Ben Scheres1
- Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- These authors contributed equally to this work.
- Present address: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
Correspondence to: Ben Scheres1 Correspondence and requests for materials should be addressed to B.S. (Email: b.scheres@uu.nl).
Factors with a graded distribution can program fields of cells in a dose-dependent manner1, 2, but no evidence has hitherto surfaced for such mechanisms in plants. In the Arabidopsis thaliana root, two PLETHORA (PLT) genes encoding AP2-domain transcription factors have been shown to maintain the activity of stem cells3. Here we show that a clade of four PLT homologues is necessary for root formation. Promoter activity and protein fusions of PLT homologues display gradient distributions with maxima in the stem cell area. PLT activities are largely additive and dosage dependent. High levels of PLT activity promote stem cell identity and maintenance; lower levels promote mitotic activity of stem cell daughters; and further reduction in levels is required for cell differentiation. Our findings indicate that PLT protein dosage is translated into distinct cellular responses.
Eu nunca leio artigos com esta plantinha tao simpatica mas vou ler este.
Beijinhos e abracos em especial para a Carla
