Endophytic Colonization of Flowering Dogwood (Cornus florida L.) and their Potential Applications
The existence of endophytic microorganisms (endophytes) has been known for over a century. Endophytes are generally defined as fungal and bacterial species existing within plants; their presence is not easily observed because host tissue colonization is internal and the infested tissues may remain asymptomatic. Many endophytes are known to produce bioactive metabolites which protect their plant hosts from various pests and pathogens. These bioactive metabolites also function in various agricultural and pharmaceutical applications ranging from biological control agents to chemotherapy treatments. The objectives of this study were to assess endophytic colonization in flowering dogwood (Cornus florida L.) plants by fungal and bacterial organisms, and determine their function as phytopathogens, biological control agents and assess their cytotoxicity based on their production of volatile compounds. Fungi and bacteria were isolated from various sections of the stems of flowering dogwood plants and cultured in nutrient media. Identification of the endophytes was based on morphological features and DNA analysis. Results from this study suggested that endophytes are not localized within the vascular tissue but are found at different sections of the stems. Some endophytes existed as latent pathogens and some were free living, producing secondary metabolites that may have medical or pharmaceutical applications. Gas Chromatography-Mass Spectrometry was used to assess the production of secondary metabolites by these endophytes. Some volatile compounds produced by these endophytes were effective in inhibiting tumor proliferation. The inhibition of tumor proliferation did not appear to be conserved across different cell lines; one endophyte, isolated was more effective on one cell line than on others.
"Endophytic Colonization of Flowering Dogwood (Cornus florida L.) and their Potential Applications"
ETD Collection for Tennessee State University.