IDENTIFYING PLANT GENES ASSOCIATED WITH BENEFICIAL FOLIAR YEASTS IN POPULUS TRICHOCARPA

The goal of the proposed research is to identify plant allelic variation associated with the abundance of epiphytic yeasts that antagonize a leaf rust pathogen, resulting in reduced rust disease.We expect to find that both yeast abundance and the level of rust antagonism are influenced by host genes associated with the physical leaf environment (e.g., cuticle composition), and genes associated with the host innate immune system. A long-term goal of this research is to develop plant genetic improvement tools that favor these beneficial yeasts in phylloplane (i.e., leaf surface) communities, thereby reducing plant disease severity. Because many disease antagonizing foliar yeasts are widespread, generalist species, managing plant-microbiome interactions to promote yeast colonization and persistence on the leaf surface may represent a tractable, though untested, practice for promoting beneficial symbiosis for enhanced disease control.The specific aims of our study are:Aim 1: Characterize the range of interactions between epiphytic yeasts of P. trichocarpa and the leaf rust pathogen, Melampsora x columbiana.Aim 2: Identify P. trichocarpa SNPs/genes associated with epiphytic yeast abundance (2a) and antagonism of M. x columbiana (2b).Aim 3: Determine how colonization order, P. trichocarpa genotype, and their interactions influence epiphytic yeast antagonism of M. x columbiana.