Abstract

Recent years have led to considerable progress in our understanding of complex real world systems and their behaviour in response to external threats or fluctuations. Much of this work relates to ‘Network Robustness’, and has been demonstrated on small and large-scale systems transcending biology, sociology, as well as ecology. We have applied this concept to assess the robustness of cellular systems against internal perturbations, taking the example of molecular events during inflorescence development.

Floral transition, one of the most critical events in the life of a plant, represents the progression from vegetative to reproductive growth. It is known to be determined not by a single gene but by a highly complex network of genes, in which LEAFY (LFY), a transcription factor with protein binding function that expresses widely in both vegetative and reproductive tissues, plays an important role as a switch that triggers flower formation by interacting and coordinating between several other genes. We have investigated floral transition at a genome-wide network level in Arabidopsis thaliana by superimposing co-expression profiles and gene ontologies of known floral genes with the available floral interactome.

My talk will cover two aspects; First, the reduction of Omics data dimensionality towards construction of the floral gene regulatory network; and Second, how random/targeted perturbations to the floral network can provide insights into the mechanism by which LFY , positively or negatively regulates the activities of other genes in the general physiology of flowering. Since LFY stands at the very centre of the network of flower development, even minute modifications in its expression/interactions may contribute to the appearance of floral structures in evolution. A dynamic analysis of network topology led to the identification of key regulatory modules of genes during flowering, apart from characterization of relationships among genes in different floral modules. In summary, this work massively expands the known floral network of Arabidopsis thaliana besides offering new perceptions on the origin of flowers.