Primary and secondary metabolism in Centaurea maculosa and their potential roles in invasion biology
Date
2008
Journal Title
Journal ISSN
Volume Title
Abstract
Centaurea maculosa is plant species native to Eurasia which has become invasive in North America, in part through allelopathic behavior. Allelopathy remains a highly debated subject, and a more firm understanding is necessary. C. maculosa is reported to secrete catechin as an allelochemical that is toxic to North American native plants. In this dissertation, a novel colorimetric assay for use in detection of catechin from soils is described and validated. This assay is highly sensitive, selective, and fast, which should allow for more detailed measures of catechin under field conditions, and ultimately a better understanding of the variation in catechin accumulation. To increase the depth of understanding of catechin biosynthesis, I report the cloning and characterization of C. maculosa dihydroflavonol reductase (CmDFR), a gene very likely to be necessary for catechin biosynthesis. To expand our view of metabolism beyond catechin, metabolome analysis is applied to field collected plant material, and demonstrate that the physiology of C. maculosa varies with the surrounding plant community -- plants growing in patches with high C. maculosa density tend to be accumulate higher levels of secondary metabolites than plants growing in the company of few conspecifics. Finally, the results of a study that clarifies the role of root exudates in structuring the soil fungal community are presented in the context of invasion biology.
This study demonstrates that root exudates are capable of influencing the soil fungal community even in the absence of the plant in a species specific manner, and that the effect of root exudates on the soil fungal community is qualitatively similar to the effect of the whole plant.
This study demonstrates that root exudates are capable of influencing the soil fungal community even in the absence of the plant in a species specific manner, and that the effect of root exudates on the soil fungal community is qualitatively similar to the effect of the whole plant.
Description
Rights Access
Subject
allelopathy
Centaurea maculosa
invasive species
secondary metabolism
soil microbes
molecular biology
plant biology