University of Kentucky
Gene Expression Profile in a Grass-Endophyte Symbiosis
Institution
University of Kentucky
Faculty Advisor/ Mentor
Christopher Schardl
Abstract
Festuca arundinacea, better known as tall fescue, is a major grazing grass in Kentucky fields. Kentucky-31, a popular cultivar of fescue, is used in much of the country because of its high drought, erosion, and insect resistance that is a product of its symbiosis with acremonium coenophialum, an endophytic fungus that lives within the plant. However, this fungus also causes fescue toxicosis in livestock. Consequent loss in weight gain in cattle costs the livestock industry a billion dollars annually. Thus much interest lies with better understanding this plant-fungal symbiosis, with the goal of developing the advantages of this symbiosis while negating the detrimental effects that livestock experience. This study has been aimed at finding key genes that trigger the switch between healthy plant (inflorescences) tissue to diseased plant tissue (stromata), which “choke” the plant thus preventing an inflorescence formation. Real time PCR (Polymerase Chain Reaction) has been utilized to compare gene expression. Samples of infloresences and stromata were collected from several genotypes of lolium pretense and agrostis, another cool season grass. The tef1 gene was shown to be abundant and steady throughout all tissue, therefore it will be used as a control gene for comparison. Various fungal genes, primarily from secondary metabolite clusters, will be tested for up regulation or down regulation with respect to tissue type. Resulting correlations will be used to trace the genetic triggers that facilitate the switch from a healthy plant in symbioses to plant “choke” by the present fungi.
Gene Expression Profile in a Grass-Endophyte Symbiosis
Festuca arundinacea, better known as tall fescue, is a major grazing grass in Kentucky fields. Kentucky-31, a popular cultivar of fescue, is used in much of the country because of its high drought, erosion, and insect resistance that is a product of its symbiosis with acremonium coenophialum, an endophytic fungus that lives within the plant. However, this fungus also causes fescue toxicosis in livestock. Consequent loss in weight gain in cattle costs the livestock industry a billion dollars annually. Thus much interest lies with better understanding this plant-fungal symbiosis, with the goal of developing the advantages of this symbiosis while negating the detrimental effects that livestock experience. This study has been aimed at finding key genes that trigger the switch between healthy plant (inflorescences) tissue to diseased plant tissue (stromata), which “choke” the plant thus preventing an inflorescence formation. Real time PCR (Polymerase Chain Reaction) has been utilized to compare gene expression. Samples of infloresences and stromata were collected from several genotypes of lolium pretense and agrostis, another cool season grass. The tef1 gene was shown to be abundant and steady throughout all tissue, therefore it will be used as a control gene for comparison. Various fungal genes, primarily from secondary metabolite clusters, will be tested for up regulation or down regulation with respect to tissue type. Resulting correlations will be used to trace the genetic triggers that facilitate the switch from a healthy plant in symbioses to plant “choke” by the present fungi.