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Identification of Human Microbiome-Active Traits (MATS) in Sorghum
There has been increasing interest in recent years in improving the nutritional quality of crops and enhancing human health, and human gastrointestinal microbiome has the potential to be used as a health trait in crop plants. Though a significant number of dietary components with microbiome activity have been defined, a major gap exists in our understanding of how these components vary in food crops and how this variation could affect the gut microbiome. Microbiome-Active Traits (MATs) in grain crops are expressed characteristics of the plant that influence interaction of grain components with the human gut microbiome. In the first study, the effect of waxy starch in whole grain sorghum on gut microbiome was evaluated using near-isogenic wild type lines and their waxy derivatives by in vitro fermentation reactions with human fecal microbiomes. Waxy derivatives result in substantial differences in overall microbiome composition, lower abundances of multiple genera from Lachnospiraceae family especially the genus of Roseburia and lower level of butyrate production across different human microbiomes. In a humanized gnotobiotic mouse model, significant differences in microbiome composition in animals fed with diets supplemented with 20% grain from isogenic wild type versus waxy sorghum derivatives were detected. Waxy sorghum-fed animals gained significantly more weight than wild type sorghum fed animals and these weight gain differences were associated with microbiome changes. The second study utilized automated in vitro microbiome screening (AiMS) strategy for phenotyping MATs variants in the sorghum BTx623 X IS3620C recombinant inbred line (RIL) and quantitative trait locus (QTL) mapping to associate with genetic variants along the sorghum genome. Overlapping QTL for MATs, seed color and tannin contents were detected and are proximal to the Tan2 and Tan1 genes that known to control tannin synthesis. Effects of tannin on microbiome were further validated using near-isogenic lines across multiple human gut microbiome. This dissertation illuminates a new way to exploit existing genetic resource populations of crop plants for integration of microbiome phenotypes into crop improvement programs and for discovery of novel health traits.
Yang, Qinnan, "Identification of Human Microbiome-Active Traits (MATS) in Sorghum" (2021). ETD collection for University of Nebraska-Lincoln. AAI28865002.