Identification of auxin molecular targets in Poaceae embryonic pattern formation

• Applicant: Dr. Christiane Fischer-Iglesias
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2005 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 13737639

Wheat embryonic patterning relies on auxin heterogeneous distribution brought about by directional transport. This project aims to study how dynamic auxin spatial distributions are interpreted and translated into a complex pattern. In particular, much attention is focused on the molecular dissection of signaling cascade(s) switched on in response to local auxin concentration that are required to built up the three dimensional body architecture of a Poaceae embryo. For this purpose, the gene expression pattern(s) of embryos that developed specific morphological alterations as a consequence of changes in their endogenous auxin distribution will be compared to the gene expression pattern(s) of normal embryos. Special attention will be paid to identify genes that may direct meristem, organ and embryonic tissue differentiation. In the course of our investigations, we have identified gene fragments specifically expressed in embryos that differentiated supernumerary meristems and organs as a result of auxin transport inhibitor treatment. One of the fragments encodes a protein having a high homology to the mammalian Glycogen synthase kinase 3 (GSK-3) and to the Drosophila Serine/threonine kinase Shaggy (SGG). These protein kinases are involved in signal transduction pathways that control patterning and cell fate determination. Another fragment has a high homology to MADS box genes that are known as key regulators in plant development. This project proposes to investigate the role of these genes in wheat and rice embryonic pattern formation. They are assumed to encode proteins that are downstream components in the auxin signaling cascade. Therefore, in parallel, a second approach based on suppression subtractive hybridization will target the identification of early/primary auxin induced genes in the signal transduction pathway(s) that direct(s) Poaceae pattern formation.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Gunther Neuhaus (†)