Dynamics of the Genetic Regulatory Network forArabidopsis thalianaFlower Morphogenesis

We present a network model and its dynamic analysis for the regulatory relationships among 11 genes that participate inArabidopsis thalianaflower morphogenesis. The topology of the network and the relative strengths of interactions among these genes were based on published genetic and molecular data, mainly relying on mRNA expression patterns under wild type and mutant backgrounds. The network model is made of binary elements and we used a particular dynamic implementation for the network that we call semi-synchronic. Using this method the network reaches six attractors; four of them correspond to observed patterns of gene expression found in the floral organs ofArabidopsis(sepals, petals, stamens and carpels) as predicted by the ABC model of flower morphogenesis. The fifth state corresponds to cells that are not competent to flowering, and the sixth attractor predicted by the model is never found in wild-type plants, but it could be induced experimentally. We discuss the biological implications and the potential use of this network modeling approach to integrate functional data of regulatory genes of plant development.