HOW DO TREES KNOW IT IS AUTUMN?

We will study the regulation of tree phenology.

We will focus on aspen (Populus tremula) aiming at, using techniques and approaches already developed, understanding more about the molecular details behind regulation of phenology, in particular autumn senescence.

We have already established a lot of basic knowledge about the process, for example that both bud set/growth arrest and onset of senescence are regulated by daylight cues, but through different mechanisms. We work primarily with analysis on natural variation in aspen in large field trials, but also with targeted mutations.

Regulation of senescence is very complex, different aspens respond to different factors, even more so under different conditions.

We would like to understand this by 1) improving our ability to make Genome-wide association studies (GWAS) in our material and subsequent production of trees with candidate genes modified and 2) create a collection of trees where “autumnal traits” either vary naturally or where different signal transduction pathways have been modified.

These will be grown both under controlled conditions and in field experiments. We will also make a “citizen science”-project on autumn senescence. The length of the growing season for a tree is not only important for climate modelers but also for tree breeders.