Project description:Selfing plant lineages are surprisingly widespread and successful in a broad range of environments, despite showing reduced genetic diversity, which is predicted to reduce their long-term evolutionary potential. However, appropriate short-term plastic responses to new environmental conditions might not require high levels of standing genetic variation. In this study, we tested whether mating system variation among populations, and associated changes in genetic variability, affected short-term responses to environmental challenges. We compared relative fitness and metabolome profiles of naturally outbreeding (genetically diverse) and inbreeding (genetically depauperate) populations of a perennial plant, <i>Arabidopsis lyrata</i>, under constant growth chamber conditions and an outdoor common garden environment outside its native range. We found no effect of inbreeding on survival, flowering phenology or short-term physiological responses. Specifically, naturally occurring inbreeding had no significant effects on the plasticity of metabolome profiles, using either multivariate approaches or analysis of variation in individual metabolites, with inbreeding populations showing similar physiological responses to outbreeding populations over time in both growing environments. We conclude that low genetic diversity in naturally inbred populations may not always compromise fitness or short-term physiological capacity to respond to environmental change, which could help to explain the global success of selfing mating strategies.
Project description:Identifying the genetic basis for natural selection is a fundamental research goal, and particularly significant for soil fungi because of their central role in ecosystem functioning. Here, we identify rapid evolutionary processes in the plant root colonizing insect pathogen Metarhizium robertsii. While adapting to a new soil community, expression of TATA box containing cell wall and stress response genes evolved at an accelerated rate, whereas virulence determinants, transposons and chromosome structure were unaltered. The survival of diversified field isolates was increased, confirming that the mutations were adaptive, and we further show that large populations of Metarhizium are principally maintained by associations with plant roots rather than insect populations. These results provide a mechanistic basis for understanding mutational and selective effects on soil microbes.
Project description:Crop resilience and yield stability are complex traits essential for food security. Sorghum bicolor is an important grain crop that shows promise for its natural resilience to drought and potential for marginal land production. We have developed sorghum lines in the Tx430 genetic background suppressed for MSH1 expression as a means of inducing de novo epigenetic variation and have used these materials to evaluate changes in plant growth vigor. Plant crossing and selection in two distinct environments revealed features of phenotypic plasticity derived from MSH1 manipulation. Introduction of epigenetic variation to an isogenic sorghum population, in the absence of selection, resulted in 10% yield increase under ideal field conditions and 20% increase under extreme low nitrogen conditions. However, incorporation of early-stage selection amplified these outcomes to 36% yield increase under ideal conditions and 64% increase under marginal field conditions. Interestingly, the best outcomes were derived by selecting mid-range performance early-generation lines rather than highest performing. Data also suggested that phenotypic plasticity derived from epigenetic variation was non-uniform in its response to environmental variability but served to reduce genotype x environment interaction. The MSH1-derived growth vigor appeared to be associated with enhanced seedling root growth and altered expression of auxin response pathways, and plants showed evidence of cold tolerance, features consistent with observations made previously in Arabidopsis. These data imply that the MSH1 system is conserved across plant species, pointing to the value of parallel model plant studies to help devise effective plant selection strategies for epigenetic breeding in multiple crops.
Project description:Populations of engineered metabolite-producing microorganisms are prone to evolutionary production declines during industrial-scale cultivations. In this study, we develop a synthetic product addiction system in E coli that addicts mevalonic acid production cells to mevalonic acid. Through experimentally simuluated long-term fermentation, we investigate how product-addicted organisms remain stable and avoid formation of genetic subpopulations of fit, non-producing cells.
Project description:Local breeds retained unique genetic variability important for adaptive potential especially in light of challenges related to climate change. Our objective was to perform, for the first time, a genome-wide diversity characterization using Illumina GoatSNP50 BeadChip of autochthonous Drežnica goat breed from Slovenia. Genetic diversity analyses revealed that the Slovenian Drežnica goat has a distinct genetic identity and is closely related to the neighboring Austrian and Italian alpine breeds. These results expand our knowledge on phylogeny of goat breeds from easternmost part of the European Alps.
Project description:The altitude gradient limits the growth and distribution of alpine plants.Alpine plants have developed strategies to survive the extremely cold conditions prevailing at high altitudes; however, the mechanism underlying the evolution of these strategies remains unknown. The alpine plant Potentilla saundersiana is widespread in the Northwestern Tibetan Plateau. In this study, we conducted a comparative proteomics analysis to investigate the dynamic patterns of protein expression of P. saundersiana located at five different altitudes. We detected and functionally characterized 118 differentially expressed proteins. Our study confirmed that increasing levels of antioxidant proteins, and their respective activities, and accumulation of primary metabolites, such as proline and sugar, confer tolerance to the alpine environment in P. saundersiana. Proteins species associated with the epigenetic regulation of DNA stability and post-translational protein degradation were also involved in this process. Furthermore, our results showed that P. saundersiana modulated the root architecture and leaf phenotype to enhance adaptation to alpine environmental stress through mechanisms that involved hormone synthesis and signal transduction, particularly the cross-talk between auxin and strictosidine. Based on these findings, we conclude that P. saundersiana uses multiple strategies to adapt to the high-altitude environment of the Northwestern Tibetan Plateau.