Format: ORAL

Aelys M. Humphreys1, Laura Schat1, Sylvia Pal-Stolsmo2, Sofia Nilsson1, Marian Schubert1,2 and Siri Fjellheim2

1 Stockholm University, Stockholm, Sweden 2 Norwegian University of Life Sciences, Ås, Norway

Grasses (Poaceae) are thought to have originated in the moist tropics in the Late Cretaceous. Their long evolutionary history has seen multiple independent transitions to open, dry habitats as well as cold and freezing ones. The 11,000 species extant today are globally distributed, occurring on all continents including Antarctica and dominating biomes ranging from topical savannahs to alpine grasslands and boreal tundra. Grasses already constitute a model clade for understanding C4 evolution and biome formation (grasslands). This research benefits from 1) a large, active community of grass taxonomists, systematists and palaeobotanists, 2) rich genetic and genomics resources, centred on economically important species such as the cereals and the model organism Brachypodium distachyon and 3) the fact that many species grow fast and have short lifecycles, making them easy to cultivate and manipulate experimentally. Despite this, and although grasses are both diverse and abundant across the coldest places on Earth, we have a relatively poor understanding of the details surrounding evolution of cold tolerance in the clade, whether repeated topical-temperate-transitions were facilitated by precursor traits, what traits characterise the species that occupy the coldest habitats and the order of events leading to the suite of adaptations that have made grasses so successful in temperate biomes today. In this talk, we will showcase grasses as a model for understanding tropical-to-temperate transitions and present ongoing multidisciplinary work across grasses as a whole, as well as in smaller clades. Comparative, experimental, ecophysiological, ecological and genetic work is providing new perspectives on cold tolerance evolution and adaptation to temperate biomes, with implications for other angiosperms as well. [[This abstract is submitted to three different symposia so is written quite generally. The talk will be tailored to the symposium where it is accepted, within the general topic indicated in this abstract.]]