A mechanistic link between STM and CUC1 during Arabidopsis development.

SPINELLI SV; ANA PAULA MARTIN; IVANA L. VIOLA; DANIEL H. GONZALEZ; JAVIER F. PALATNIK

PLANT PHYSIOLOGY.

AMER SOC PLANT BIOLOGISTS

Año: 2011 vol. 156 p. 1894 - 1904

0032-0889

The KNOXI transcription factor SHOOT MERISTEMLESS (STM) is required to establish andmaintain the Arabidopsis thaliana apical meristem, yet little is known about its direct targets.Using different approaches we demonstrate that the induction of STM causes a significant upregulationof the organ boundary gene CUC1, which is specific and independent of othermeristem regulators. We further show that the regulation of CUC1 by STM is direct andidentify putative binding sites in its promoter. Continuous expression of STM in Arabidopsisleaf primordia also causes the activation of CUC2-3, as well as microRNA MIR164a, whichprovides a negative feedback loop by post-transcriptionally regulating CUC1 and CUC2. Theresults bring new insights into the mechanistic links between KNOXI and CUC transcriptionfactors and contribute to the understanding of the regulatory network controlled by STM.