THE INS AND OUTS OF OVULE DEVELOPMENT

In the past few years, ovule development has been widely studied in different plant species, both from a morphological and a more molecular point of view. At early stages of flower development, the placenta becomes specified inside the carpel and ovules develop from this tissue asmeristematic protuberances. Shortly after, a complicated genetic network regulates ovule patterning controlling the differentiation of three regions named funiculus, chalaza and nucellus. In the past decade, genes playing important roles during ovule development have been identified, and in a few cases, genetic models that could explain the molecular relationship among these genes have been proposed. Here we focus our attention on the molecular genetic mechanisms that stand at the base of ovule development in the model species Arabidopsis thaliana and we report an updated description of the molecular networks controlling both sporophytic and gametophytic tissue development in the ovule. Furthermore, we observe that the mechanisms controlling ovule development seem to be evolutionary conserved, even in a distantly related species such as rice.