Quercetin influences response in Nicotiana megalosiphon infected by satellite-associated cucumber mosaic virus

In vitro system for studying interactions betweenCitrus exocortis viroidandGynura aurantiaca(Blume) DC. metabolism and growing conditions

“…The phenylpropanoid pathway is responsible for the synthesis of a large range of natural products in plants including flavonoids. Although function of these low-weight benzopyranes in acting as signal molecules in plantÁmicrobe interactions is well documented (Dooner et al 1991;Koes et al 1993;Shirley et al 1995), knowledge about their role in the plant disease development and/or defense response to viruses is limited (Rusak et al 1997;Rusak et al 2007;Krcatovic´et al 2008) and there are no data about the way in which these compounds could affect disease development in viroid-infected plants.…”

Complex formation of quercetin with lanthanum enhances binding to plant viral satellite double stranded RNA

“…Therefore the control of replication and spreading of sat RNA in CMV infected plants could lead to the control of symptoms development and outcome of the viral diseases. It should be mentioned that the antiphytoviral activity of quercetin in satellite-associated CMV infected plants is documented [3] but the mechanism of this activity was not fully clarified. It is interesting that these results showed that attenuation of yellowing symptoms in sat CMV infected plants treated by quercetin was accompanied by lower expression of both viral and satellite dsRNA.…”

“…These low molecular weight phenylbenzopyranes were shown to be potential protectors against a variety of human diseases, in particular cardiovascular diseases and cancer [1]. Also, they have been found to possess antiviral [2][3][4], antiallergic and anti-inflammatory effects [1]. Although it was initially hypothesized that such broad spectrum of biological activities of flavonoids would be related to their antioxidant properties, recent studies suggest that many of the biological effects of flavonoids are due to their ability to modulate cell signaling pathways.…”

“…However, these results were obtained by using synthetic polynucleotides but there is no report on the interaction of QLa 3+ with any biologically important molecule isolated from biological material. Recently, we have shown that Q influences the defense response in Nicotiana megalosiphon infected by cucumber mosaic virus (CMV) associated with a satellite RNA [3] but the mechanism of this interaction still remains unclear. CMV is a small icosahedral virus with a tripartite genome and two subgenomic RNAs.…”

Phenolic Compounds in Centaurea rupestris Tissues and Their Antiphytoviral Activity

“…7 Krcatović et al 8 demonstrated inhibition of TMV infection by quercetin and vitexin. Quercetin also induced resistance to Potato virus X (PVX) in Chenopodium quinoa 9 and was active against Tomato ringspot virus 10 and Cucumber mosaic virus, 11 while it acted synergistically with ribavirin against Apple stem grooving virus. 12 Flavonoid quercetagetin 3'-methylether-7-O-ß-D-glucopyranoside (MQ), isolated from the inflorescences of Croatian endemic species Centaurea rupestris L. 13 interferes with the initiation of Tomato bushy stunt virus (TBSV) infection 14 and it also has antibacterial and antifungal activities.…”