Principal investigator:

Greb, Thomas, Prof. Dr.,
Centre for Organismal Studies (COS)

Abteilung für Entwicklungsphysiologie

Im Neuenheimer Feld 230

69120 Heidelberg

Phone: +49 6221 54-5524

E-mail: thomas.greb@cos.uni-heidelberg.de

Summary:

Coordinating the proliferation of stem cells and the differentiation of their immediate derivatives is fundamental for the performance of higher organisms. Plant stem cells niches rely on the establishment of functional subdomains by mutual intercellular communication between cells residing in those domains. These interactions guarantee a robust but dynamic flow of cells from the stem cell pool to the differentiated tissues they generate. Interestingly, although regulatory loops determining stem cell activity are similar when distinct plant stem cell systems are compared, their anatomy as well as their cellular products are specific. The basis of this specificity is, however, unknown. In this project, we will leverage our finding that a regulatory loop consisting of the transcription factors ARF5/MONOPTEROS (MP) and WUSCHEL-RELATED HOMEOBOX4 (WOX4) is important for coordinating stem cell-to-xylem transition in the cambium of Arabidopsis thaliana. Because MP also acts in the shoot apical meristem and functionally interacts with the WOX4 homolog WUSCHEL (WUS), analysis of this loop will allow dissecting similarities and differences between MP-WOX loops in different contexts. In particular, we will i) analyse promoter binding properties of MP and WOX4 proteins, ii) modulate the activities of the two putative loop members in different genetic backgrounds, and iii) change the spatial specificity of MP and WOX4 gene activities. In close collaboration with B07 led by Jan Lohmann and other consortium members working on similar loops, we thereby will reveal mechanisms mediating specificity of tissue production and of anatomical features of distinct plant stem cell systems.