Browsing by Author "Bowerman, Peter A."
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- Analysis of T-DNA alleles of flavonoid biosynthesis genes in Arabidopsis ecotype ColumbiaBowerman, Peter A.; Ramirez, Melissa V.; Price, Michelle B.; Helm, Richard F.; Winkel, Brenda S. J. (2012-09-04)BACKGROUND: The flavonoid pathway is a long-standing and important tool for plant genetics, biochemistry, and molecular biology. Numerous flavonoid mutants have been identified in Arabidopsis over the past several decades in a variety of ecotypes. Here we present an analysis of Arabidopsis lines of ecotype Columbia carrying T-DNA insertions in genes encoding enzymes of the central flavonoid pathway. We also provide a comprehensive summary of various mutant alleles for these structural genes that have been described in the literature to date in a wide variety of ecotypes. FINDINGS: The confirmed knockout lines present easily-scorable phenotypes due to altered pigmentation of the seed coat (or testa). Knockouts for seven alleles for six flavonoid biosynthetic genes were confirmed by PCR and characterized by UPLC for altered flavonol content. CONCLUSION: Seven mutant lines for six genes of the central flavonoid pathway were characterized in ecotype, Columbia. These lines represent a useful resource for integrating biochemical and physiological studies with genomic, transcriptomic, and proteomic data, much of which has been, and continues to be, generated in the Columbia background.
- Exploring protein interactions and intracellular localization in regulating flavonoid metabolismBowerman, Peter A. (Virginia Tech, 2010-08-02)The organization of biological processes via protein-protein interactions and the subcellular localization of enzymes is believed to be fundamental to many aspects of metabolism. Although this organization has been demonstrated in several systems, the mechanisms by which it is established and regulated are still not well understood. The flavonoid biosynthetic pathway offers a unique system in which to study several important aspects of metabolism. Here we describe a novel toolset of mutant alleles within the flavonoid biosynthetic pathway. In addition, we discuss the use of several of these alleles together with a number of emerging technologies to probe the role of subcellular localization of chalcone synthase, the first committed flavonoid biosynthetic enzyme, on metabolic flux, and to characterize a novel chalcone synthase-interacting protein. The over-expression of this interacting protein induces novel phenotypes that are likely associated with the production or distribution of auxin. Further, interaction analyses between recombinant flavonoid biosynthetic enzymes point to the possibility that post-translational modifications play an important role in promoting interactions.
- Identification of MOS9 as an interaction partner for chalcone synthase in the nucleusWatkinson, Jonathan I.; Bowerman, Peter A.; Crosby, Kevin C.; Hildreth, Sherry B.; Helm, Richard F.; Winkel, Brenda S. J. (PeerJ, 2018-09-19)Plant flavonoid metabolism has served as a platform for understanding a range of fundamental biological phenomena, including providing some of the early insights into the subcellular organization of metabolism. Evidence assembled over the past three decades points to the organization of the component enzymes as a membrane-associated complex centered on the entry-point enzyme, chalcone synthase (CHS), with flux into branch pathways controlled by competitive protein interactions. Flavonoid enzymes have also been found in the nucleus in a variety of plant species, raising the possibility of alternative, or moonlighting functions for these proteins in this compartment. Here, we present evidence that CHS interacts with MOS9, a nuclear-localized protein that has been linked to epigenetic control of R genes that mediate effector-triggered immunity. Overexpression of MOS9 results in a reduction of CHS transcript levels and a metabolite profile that substantially intersects with the effects of a null mutation in CHS. These results suggest that the MOS9–CHS interaction may point to a previously-unknown mechanism for controlling the expression of the highly dynamic flavonoid pathway.