High antioxidant activity of phenolic compounds dampens oxidative stress in Espinosa nothofagi galls induced on Nothofagus obliqua buds

• Published in: Plant science (Limerick) 2022-01, Vol.314, p.111114-111114, Article 111114
• Main Authors: Guedes, Lubia María, Torres, Solange, Sáez-Carillo, Katia, Becerra, José, Pérez, Claudia I., Aguilera, Narciso
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants - metabolism; Chile; Fagales - metabolism; Fagales - parasitology; Flavonols; Host-Parasite Interactions - drug effects; Inner tissue compartment; Insecta - metabolism; Lignin; Outer tissue compartment; Oxidative Stress - drug effects; Phenols - metabolism; Plant Tumors - parasitology; Polyphenols; Reactive oxygen species; Signal Transduction - drug effects
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2021.111114

•Espinosa nothofagi galls produce and accumulate ROS in their tissue compartments.•Phenolic and flavonols co-occurrence with ROS in the inner and outer compartments.•ROS accumulation in Espinosa nothofagi galls triggers synthesis of phenolic compounds.•The highest polyphenols concentration and lignin deposition occurs in the inner compartment.•The extract from the inner gall compartment has the highest antioxidant capacity. Reactive oxygen species (ROS) are considered the first signaling molecules involved in gall development, linked to the establishment of cyto-histological gradients leading to gall tissue redifferentiation. ROS overproduction induces the failure of gall establishment or its premature senescence. Galls could therefore have efficient mechanisms of ROS dissipation and maintenance of homeostasis, such as polyphenol synthesis. The co-occurrence of ROS and polyphenols in the Espinosa nothofagi galls induced on Nothofagus obliqua buds was explored and was related to the antioxidant capacity of the inner (IC) and outer (OC) gall compartments. We hypothesize that: (i) ROS are produced and accumulated in both tissue compartments of E. nothofagi galls in co-occurrence with polyphenolic, flavonols, and lignin, conferring high antioxidant activity to inner and outer gall tissue compartment; (ii) antioxidant activity is higher in IC related to a higher polyphenol concentration in this compartment. The results show that ROS and polyphenols, mainly flavonols, are produced and accumulated in IC and OC, while lignin accumulated mainly in the IC. In both gall compartments, polyphenols mediate ROS elimination, confirmed by histochemical and spectrophotometry techniques. The IC extract has the highest antioxidant capacity, probably due to lignin deposition and a higher polyphenol concentration in this compartment.