Genetic variation in transcriptional, proteomic and metabolic responses of S. cerevisiae to herbicides

West Virginia University Research Corporation, Morgantown WV

Investigators

Abstract

This proposal is to study the evolutionary changes that have been occurring in wild yeasts in the last several decades. Yeast are one of the oldest domesticated organisms, but it was only recently that wild yeasts resistant to herbicide Roundup became known. The highest levels of resistance are observed in the strains collected from agricultural soils that have been treated with Roundup in the last 40 years. In depth genetic analysis of six strains definitively showed that resistance is achieved in a different way from what is observed in Roundup-resistant plants. State-of-the-art genome sequencing technologies will be applied to study the genetic changes that have caused these adaptations to a chemical that is not observed in nature. The project will be done with the help of 6-12th grade students from rural West Virginia schools, science outreach programs at WVU Arboretum and Upward Bound (a TRiO program), in which citizen scientists will find and study yeasts from their own neighborhoods. The objective of this project is to identify genes that vary in S. cerevisiae strains with different resistance to herbicides. The working hypothesis is that Roundup resistance is linked to polymorphic regions of the genome that have been selected for by exposure to Roundup. The approach to addressing this question is to map Quantitative Trait Loci (QTL) responsible for herbicide resistance by using recombinant haploid collections between sensitive and resistant strains. With the high-throughput sequencing approaches, responsible gene products will be identified, most likely in chorismate metabolism, small molecule transport and possibly other pathways. The collection of isolates and their preliminary characterization will be done through several outreach and citizen-science initiatives.