CONICET | Buscador de Institutos y Recursos Humanos

A main question in developmental biology is how cells make decisions which arebased on determinants that cells inherit from its precursor, molecular dialogueswith neighboring cells and signals that cells perceive from its environment. Thesignal transduction cascade of mitogen activated pro tein kinases (MAPKs) is a keycomponent in the integration of signals that determine cell identity and terminalfate. An ideal model to study the integration of MAPK signals and development inplants is the cellular lineage that generates stomata in Arabidopsis. Stomas are thevalves that contr ol gas exchange in the epidermis and their precursors have theability to tune their development to information from neighbor cells and theenvironment. Using stomatal development as context, we found that artificialactivation of a specific MAPK cascade i nduces stomatal precursor proliferation. Amutant suppressor screening on a stomatal hyperproliferating line revealedadditional components of the cascade. Interestingly, when validating the roles ofthe MAPK cascade in stomatal development, we found that precursor proliferationand cell cycle arrest were controlled by the same MAPK components. We presentour advances on how the same signaling components mediate antagonistic rolesin stomatal precursors and generate specific phenotypical outputs. Since MAPKcascades are highly conserved in eukaryotes, we predict that some of thesestrategies could be conserved in different species.