Flavonoids: New Roles for Old Molecules

Abstract

Flavonoids are ubiquitous in the plant kingdom and have many diverse functions including defense, UV protection, auxin transport inhibition, allelopathy, and flower coloring. Interestingly, these compounds also have considerable biological activity in plant, animal and bacterial systems -such broad activity is accomplished by few compounds. Yet, for all the research over the last three decades, many of the cellular targets of these secondary metabolites are unknown. The many mutants available in model plant species such as Arabidopsis thaliana and Medicago truncatula are enabling the intricacies of the physiology of these compounds to be deduced. In the present review, we cover recent advances in flavonoid research, discuss deficiencies in our understanding of the physiological processes, and suggest approaches to identify the cellular targets of flavonoids.Buer CS, Imin N, Djordjevic MA (2010) Flavonoids: new roles for old molecules.

Auxin and Ethylene Induce Flavonol Accumulation through Distinct Transcriptional Networks

“…One report detected flavonols by in situ DPBA staining of plants grown with roots in the dark and shoots in the light (Buer and Muday, 2004), while another did not find flavonols in roots grown in darkness and examined in extracts separated by highpressure thin-layer chromatography followed by DPBA staining (Stracke et al, 2010a). Accumulation of flavonols in dark-grown roots may be consistent with long-distance communication of light-dependent signals to the roots or movement of flavonols from the shoot into the root (Buer et al, 2007(Buer et al, , 2008(Buer et al, , 2010. The nature of this signal may in fact be flavonoid precursors themselves, which have been shown to move from an Figure 9.…”

Polyphenolic content and bactericidal effect of Mexican Citrus limetta and Citrus reticulata

“…Citrus flavonoids, in particular, are recognized as antioxidants (Procházková et al 2011;Yu et al 2014;Asikin et al 2015), antifungals (Buer et al 2010), antimicrobials (Vikram et al 2010;Cushnie and Lamb 2011;Céliz et al 2011), and even accelerating wound and disease healing (Neves et al Neves et al 2010;Arab and Liebeskind 2010;Codoñer-Franch and Valls-Bellés 2010;Wang et al 2014). In plants, flavonoids appear to play defensive roles against pathogens, including bacteria, fungi and viruses; these are generally found in glycosylated forms in plants, and the sugar moiety is an important factor determining their bioavailability (Agati et al 2012).…”

Seasonal variation in allelopathic potential of the leaves of Copaifera langsdorffii Desf.

“…Flavonoids are common polyphenol compounds that are distributed widely in food plants (Buer et al 2010). As a class, fl avonoids are best known for their antioxidant activities (Bais et al 2003), but they also serve as communication signals between cell membranes, as regulators of cell growth, inducers of detoxifying enzymes, and inhibitors of seedling germination and growth (Macias et al 1997;Yang et al 2000;Hoagland & Williams 2004).…”