"Being sessile and unable to regulate their internal temperature, plants are exposed to large variations in ambient temperature during day-night cycles and seasonal changes. It is clear that plant development and growth are closely related to thermal conditions, but the molecular mechanisms involved in temperature sensing are not understood. Plant responses to changing ambient temperature are becoming increasingly important from an applied perspective, due to the projected 2.0-5.4°C global warming by the end of this century. To understand plant responses to temperature, we need to resolve the molecular components involved in temperature perception and signalling. I will use a multidisciplinary approach combining molecular genetics and growth and developmental analysis to understand temperature perception and responses in the emerging model monocot system Brachypodium distachyon. The results will be highly relevant for other temperate grasses and cereals, due to their close phylogenetic relationship. First, the temperature effect on Brachypodium leaf meristem functioning will be quantified using kinematic methods, making use of new reporter lines for meristematic activity. Second, the genetic network involved in correct ambient temperature sensing and signalling will be identified by extensive forward genetic screening based on LUC reporters and fast neutron deletion mutant populations. The gene mapping will be strongly enhanced using whole genome tiling arrays. The GA/DELLA pathway has been shown to restrain growth in adverse conditions in Arabidopsis. The third objective of this proposal is to identify components of the GA/DELLA pathway in Brachypodium in a reverse genetic approach by screening the genomic DNA bank of fast neutron deletion lines for the predicted DELLA gene(s), and by a complementary forward genetic screen. Genes will be mapped by whole genome tiling array hybridisations, and their role in growth responses to temperature will be assessed."