TIR1 proteins are F-box proteins that have three different domains giving them the ability to bind to three different ligands: an SCF TIR1 ubiquitin ligase complex (using the F-box domain), auxin  (so TIR1 proteins are auxin receptors), and Aux/IAA proteins (via a degron domain). Upon binding of auxin, a TIR1 protein's degron domain has increased affinity for Aux/IAA repressor proteins, which when bound to TIR1 and its SCF complex undergo ubiquitination and subsequent degradation by a proteasome . The degradation of Aux/IAA proteins frees ARF proteins to activate or repress genes at whose promoters they are bound. 
Understanding the drivers of population divergence, speciation and species persistence is of great interest to molecular ecology, especially in the world's biodiversity hotspots. East Asia is one of regions harboring the most diverse temperate and subtropical flora in the world. Although this region has never been directly impacted by extensive and unified ice-sheets, it nonetheless experienced severe environmental change throughout the Late Tertiary and Quaternary with dramatic effects on the evolution and distribution of plants. By using phylogeographic, landscape genetic, and ecological modelling approaches, a steadily increasing number of phylogeographic studies in East Asia have documented the evolutionary web of population demographic, biogeographic, and speciation processes. This symposium will present recent remarkable studies concerning phylogeographic patterns, population demographic/biogeographic histories, speciation processes, as well as drivers of species diversification and persistence that have given rise to one of the world's most diverse floras in East Asia.