Flavonoid profiling and nodulation of some legumes in response to the allelopathic stress of Sonchus oleraceus L.

Abstract

Annual sowthistle (Sonchus oleraceus) has been reported to produce allelopathic effects. Two greenhouse experiments were conducted to estimate the allelopathic potential of both plant residue and root exudates of S. oleraceus on flavonoid composition and nodulation in a leguminous crop, Trifolium alexandrinum, and in two leguminous weeds, Melilotus indicus and T. resupinatum. The results of high performance liquid chromatography-mass spectrometry (HPLC--MS/MS) showed that all three legumes contained six flavonoid aglycones: apigenin, daidzein, kaempferol, luteolin, myricetin and quercetin; and seven flavonoid glycosides: daidzin, genistin, hesperidin, hyperoside, kaempferol-7-O--glucoside, naringin and rutin. In general, both plant residue and root exudates had inhibitory effects on the flavonoid composition and nodulation of the target species. However, residue of S. oleraceus caused a significant increase in both individual and total detected flavonoids in T. alexandrinum. The results suggest that the phytotoxins released from S. oleraceus may restrain the biosynthesis of flavonoids in the target species, whereas the accumulated flavonoids in T. alexandrinum are allelopathic-induced metabolites and suggest a resistance mode in this crop.

Metabolome and Transcriptome Analysis of the Response Mechanisms of Ginseng to Rust Root Symptoms

“…Studies have shown that avonoids are also one of the main chemical defense substances in plants and can reduce various forms of reactive oxygen species in plant cells, which are usually produced in response to external environmental stresses such as light intensity, temperature, and soil moisture [35]. Besides, it is also an active substance involved in plant-microbe interactions [36]. In our results, a signi cant upregulation of a large number of avonoids was found.…”

Variation in Soil Microbial Community Structure Associated with Different Legume Species Is Greater than that Associated with Different Grass Species

“…Consequently, root exudates are probably the primary cause responsible for the difference between legume and grass, that is, the root exudate profile differs much among three legume species, while its does not among three grass species. The root exudate profiles were not characterized in this study; however, it is well acknowledged that flavonoids in the root exudates of legume differ much among different species (Gomaa et al, 2015 ). It is also the case for the amino acids and organic acids in root exudates.…”

Rhizobium-Linked Nutritional and Phytochemical Changes Under Multitrophic Functional Contexts in Sustainable Food Systems

“…The key determinants of specificity in rhizobium-legume relationships are lipo-chitooligosaccharide compounds known as Nod factors secreted by rhizobium strains (Mergaert et al, 1997;Geurts and Bisseling, 2002;Soto et al, 2006), in response to flavonoid signaling compounds in root exudates (Clúa et al, 2018). Flavonoid compounds such as the flavonoid aglycones (apigenin, daidzein, kaempferol, luteolin, myricetin, and quercetin) and the flavonoid glycosides (daidzin, genistin, hesperidin, hyperoside, kaempferol-7-Oglucoside, naringin, and rutin) have been detected in root exudates of the leguminous plants Melilotus indicus, Trifolium alexandrinum, and T. resupinatum (Gomaa et al, 2015). Compatible interactions based on plant flavonoids and rhizobial Nod factors trigger a series of events that lead to successful infection and development of nodules that can fix nitrogen (Wang et al, 2018).…”

“…Antagonistic plants can also release allelochemicals that interfere with leguminous host plants and symbiotic Rhizobium species in the rhizosphere (Rice, 1992;Kluson, 1995). For instance, the weed Sonchus oleraceus (Asteraceae) produces allelochemicals that inhibit the production of flavonoid compounds and root nodulation in the leguminous weeds Melilotus indicus and Trifolium resupinatum (Gomaa et al, 2015).…”

“…Besides flavonoids, legumes also produce strigolactone allelochemicals that enhance Rhizobium activities on host roots (Peláez-Vico et al, 2016;McAdam et al, 2017), while stimulating the germination of arbuscular mycorrhizal fungi that facilitate phosphorus acquisition for improved nitrogen fixation (Püschel et al, 2017;Kafle et al, 2019). Positive allelopathy also exists in the leguminous crop Trifolium alexandrinum, which is induced to release high level of flavonoid compounds as a resistance response toward phytotoxic allelochemicals produced by the weed Sonchus oleraceus (Gomaa et al, 2015).…”