Transcription factors in Flower Development - Molecular Biology

1. Transcription factor complexes controlling flower development and their target genes

Description

Flower development is one of the best understood and economically most important developmental processes in plants. It serves as a model system to understand organ specification and cellular differentiation, starting from pools of undifferentiated ‘stem cells’ residing in meristems. Flower development is controlled by transcription factors of the MADS-box family. These proteins act as major developmental switches to specify the identity of floral meristems and floral organs. They supposedly act in larger protein complexes that bind to the promoters of target genes and regulate them in an organ-specific fashion. We want to understand how and why MADS protein complexes control the expression of their target genes in different floral organs and at different stages during flower development. The goal of this project is to identify MADS-box target genes that are dynamically regulated during development based on the results of genome-wide DNA-binding and expression studies. The expression dynamics of these target genes will be studied using fluorescent reporter gene studies (e.g. GFP). Binding of MADS-domain proteins and protein complexes will be studied by chromatin immunoprecipitation (ChIP) in planta and/or by Electrophoretic Mobility Shift Assays (EMSAs) in vitro.

Methods

Gateway cloning, plant transformation, Confocal microscopy (CLSM), chromatin immunoprecipitation, Realtime quantitative PCR, Electrophoretic Mobility Shift Assays (EMSAs)

2. Spatiotemporal expression dynamics of MADS-box transcription factors in flower development

Description

Flower development in Arabidopsis is controlled by transcription factors of the MADS-box family. These proteins act as major developmental switches to specify the identity of floral meristems and floral organs. According to the current model of flower development, MADS-box transcription factors interact in a combinatorial fashion to specify the different types of floral organs, and to control organ differentiation and growth. MADS proteins are expressed in a highly cell-type specific and temporally dynamic fashion in developing flowers. The goal of this project is to characterize and quantify MADS protein expression levels during flower development at the cellular level using fluorescent reporter gene analysis. These data will be used for modelling approaches to understand regulatory interactions within the MADS-box transcription factor network that are essential for flower formation.

Methods

Handling Arabidopsis - genotyping, making crosses, phenotypic analysis. Confocal microscopy (CLSM), CLSM data analysis.