Phytochemical and Antioxidant Dynamics of the Soursop Fruit (Annona muricataL.) in response toColletotrichumspp.

Abstract

This work evaluates the effect of the pathogens Colletotrichum siamense and C. gloeosporioides on the response of soursop fruits. The bioactive compounds (total phenols, flavonoids, anthraquinones, coumarins, steroids, terpenoids, alkaloids, and saponins) were evaluated qualitatively in soursop pulp. Positive phytochemicals and antioxidant activity (DPPH•, ABTS•+, and FRAP) were quantified at day zero, one, three, and five. Fruits treated with C. gloeosporioides showed higher disease severity (P<0.05). Early fruit response (day one) was observed with both pathogens, increased the concentration of saponins and repressed the production of quercetin 3-O-glucoside (P<0.05). Likewise, C. siamense decreased total soluble phenols and flavonoids and increased antiradical activity DPPH•. Besides, C. gloeosporioides decreased the levels of kaempferol 3-O-rutinoside and ferulic acid (P<0.05). Regarding the late response (day three), both pathogens decreased the concentration of saponins and increased flavonoids and phytosterols (P<0.05). Nevertheless, C. siamense increased the levels of total soluble phenols, p-coumaric acid, kaempferol, and antiradical activity FRAP (P<0.05). Also, C. gloeosporioides repressed the production of quercetin 3-O-glucoside at day five (P<0.05). Soursop fruits had a response to the attack of Colletotrichum during ripening at physicochemical and oxidative levels, which is associated with the production of compounds related to the development inhibition of pathogens. Even so, soursop fruits showed higher susceptibility to C. gloeosporioides and higher sensitivity to the attack of C. siamense.

Assessment of the changes in product characteristics, total ascorbic acid, total flavonoid content, total polyphenol content and antioxidant activity of dried soursop fruit tea (Annona muricata L.) during product storage

“…This reduction aligns with the principles of antioxidant activity in soursop fruit, as previously elucidated by Rubio‐Melgarejo et al. ( 2020 ).…”

Differential Responses of Antioxidative System during the Interaction of Soursop Fruits (Annona muricata L.) and Nectria haematococca at Postharvest Storage

“…These compounds are involved in the response of plants against beneficial organisms and pathogens with superposition of some active signals by the plant and adaptive responses that help to protect against aggressive pathogens [ 7 ]. Rubio-Melgarejo et al [ 8 ] reported, in soursop fruits non-inoculated and inoculated with Colletotrichum gloeosporioides, a trend of increase from day one to day five of storage in the FRAP activity. In this study, control fruits showed an increase in their FRAP capacity from day one to three, showing similar results to those previously mentioned.…”

“…In turn, Spoel and Dong [ 20 ] mention that the increase in ABTS•+ could be to an adaptation mechanism of plants, in their ability to recognize and respond quickly to a possible invader through defense responses such as the production of secondary metabolites such as phenolic compounds. Furthermore, Rubio-Melgarejo et al [ 8 ] reported an increase in antioxidant capacity on the radical ABTS•+ on day one in soursop fruits inoculated with C. siamense . Our results showed a decrease in the antioxidant capacity in inoculated fruits, suggesting that it can alter the signal network and manipulate the defenses using virulence effectors.…”

“…Given the multiplicity of interactions, plants present a wide flexibility of responses to beneficial organisms and pathogens through activated signals and adaptive responses of the plant to pathogens, generating a sophisticated network of signals; the processes of synergism and antagonism between pathways of signaling allows to refine the most adequate defense mechanism [ 7 ]. Rubio-Melgarejo et al [ 8 ] mentioned that the production of secondary metabolites such as phenols, and the increase in oxidative levels, play an essential role in interactions such as chemical defense against pathogens, inhibiting their development. One of the plant defense mechanisms is the enzymatic antioxidant system, as well as the regulation and production of reactive oxygen species (ROS) for the defense in plants [ 9 ].…”

The diversity of endophytic fungi in Tartary buckwheat (Fagopyrum tataricum) and its correlation with flavonoids and phenotypic traits

“…Furthermore, two Colletotrichum strains isolated from Andrographis paniculata exhibited substantial antioxidant activity and produced high yields of total phenols and flavonoids (Li Q. et al, 2022). Another study found that after exogenous inoculation with a Colletotrichum strain, the content of total flavonoids, soluble total phenols, coumarins, and kaempferol increased in the body of Annona muricata (Rubio-Melgarejo et al, 2020). Based on the aforementioned findings, we speculated that Colletotrichum, as an endophytic fungus in Tartary buckwheat, was capable of producing abundant levels of flavonoids and other polyphenols.…”