Transcriptomic Analysis of Avocado Hass (Persea americana Mill) in the Interaction System Fruit-Chitosan-Colletotrichum

Abstract

Avocado (Persea americana) is one of the most important crops in Mexico as it is the main producer, consumer, and exporter of avocado fruit in the world. However, successful avocado commercialization is often reduced by large postharvest losses due to Colletotrichum sp., the causal agent of anthracnose. Chitosan is known to have a direct antifungal effect and acts also as an elicitor capable of stimulating a defense response in plants. However, there is little information regarding the genes that are either activated or repressed in fruits treated with chitosan. The aim of this study was to identify by RNA-seq the genes differentially regulated by the action of low molecular weight chitosan in the avocado-chitosan-Colletotrichum interaction system. The samples for RNA-seq were obtained from fruits treated with chitosan, fruits inoculated with Colletotrichum and fruits both treated with chitosan and inoculated with the fungus. Non-treated and non-inoculated fruits were also analyzed. Expression profiles showed that in short times, the fruit-chitosan system presented a greater number of differentially expressed genes, compared to the fruit-pathogen system. Gene Ontology analysis of differentially expressed genes showed a large number of metabolic processes regulated by chitosan, including those preventing the spread of Colletotrichum. It was also found that there is a high correlation between the expression of genes in silico and qPCR of several genes involved in different metabolic pathways.

Chitosan biopolymer promotes yield and stimulates accumulation of antioxidants in strawberry fruit

“…Although mechanism of chitosan induced higher fruit yield and accumulation of antioxidants in strawberry fruit are not explored in the current study, we propose a hypothetical pathway in Fig 4 . A further study is needed for validation of our proposed hypothesis [ 22 , 23 ].…”

“…Recent transcriptomic analysis reveals that chitosan induces expression of genes involved in multiple physiological processes including systemic acquired resistance, plant immune system, photosynthesis and hormone metabolism. It also influenced expression of heat-shock protein and re-programming of protein metabolism with an increment of storage proteins [ 22 , 23 ]. However, information on field application of chitosan for enhancing yield and human health benefiting biochemical contents in small fruit is scant.…”

Alternative Eco-Friendly Methods in the Control of Post-Harvest Decay of Tropical and Subtropical Fruits

“…The physiological mechanisms of the fruit are positively affected by the application of chitosan at post-harvest management under biotic and abiotic stress, that is why the post-harvest shelf-life and quality (firmness, appearance, color) of fruit can be maintained during the storage time, besides the respiration rate and ethylene production of fruits decrease [31]. Some studies reported an enhanced content of total soluble solids, ascorbic acid, the nutritional value, and acceptability [30,32,33]. Chitosan is compatible with other substances like organic salts, gums, or essential oils, and this alternative can improve their efficacy against pathogens due to a synergistic effect [34,35].…”

Chitosan biopolymer improves the fruit quality of litchi (Litchi chinensis Sonn.)

“…Chitosan has been widely used as a coating agent of various fruits mainly for protection from postharvest losses, enhancing the storability and preservation [9,[14][15][16][17][18]. A large body of literature indicates that foliar application of CHT increases vegetative growth, yield and induces synthesis of secondary metabolites, such as polyphenolics, lignin, flavonoids, and phytoalexins in plants [19][20][21][22][23]. It also promotes expression of genes involved in hormone metabolism, photosynthesis, the plant immune system, heat-shock proteins, systemic acquired resistance, and reprogramming of protein metabolism with an increment of storage proteins [24,25].…”