A carregar...
Publicação
Assessment of melatonin as a priming agent against fruit decay due to fungal infections in table grapes
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 11.62 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
Table grapes production is of great economic and social importance. However, they are highly susceptible to fungal infections during transport and postharvest storage, which limits their commercial shelf life and quality. Controlling fungal infections relies, primarily, on the application of chemical fungicides, which has raised concerns in terms of environmental, public health, and pathogen resistance. Therefore, the search for more sustainable and effective strategies is important. Melatonin, N-acetyl-5-methoxytryptamine, has emerged as a molecule of great interest in plant physiology research, playing a variety of roles, including in response to biotic and abiotic stresses. The main objective of this study was to evaluate the impact of exogenous melatonin application on the response of table grapes to postharvest fungal infections, clarifying the molecular mechanisms responsible for the priming effect. The results showed that no significant differences in the incidence and severity of fungal infections were observed, possibly due to the occurrence of cracks on the surface of grape berries of the Sugra 48 cultivar, after prolonged immersion in the solution. This study demonstrates that melatonin did not have a direct antifungal effect but played an important role in modulating the response of table grapes to postharvest fungal infections. This priming effect was observed at the transcriptomic level, through the regulation of genes with a putative differential expression, like ABI3, gibberellin 20-oxidase and invertase/pectin methylesterase inhibitor gene, associated with structural reinforcement and stress regulation. On the other hand, for example, genes with a putative differential expression related to ethylene biosynthesis and stilbene regulation were repressed, suggesting a reprogramming of defense pathways. The metabolomics analysis showed an increase in secondary compounds was observed in fruits treated with melatonin, but without significant differences. Flavonoids, stilbenes and triterpenoids were identified, associated with antioxidant properties, a role in pathogen defense, and maintenance in fruit integrity. In conclusion, treatment with exogenous melatonin can be seen as a complementary and sustainable strategy, reducing the use of chemicals products and contributing to improved postharvest quality and increased shelf life of table grapes. However, additional studies are needed on different table grape cultivars and review and improvement of application methodologies.
Descrição
Tese de Mestrado, Bioquímica e Biomedicina, 2025, Universidade de Lisboa, Faculdade de Ciências
Palavras-chave
Post-harvest Melatonin Transcriptomics Metabolomics