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.
Highlights
The avocado (Persea americana) cv Hass, is from the economic point of view, one of the most important fruits in Mexico because it is the main producer, exporter and consumer of this fruit in the world
Colletotrichum gloeosporioides is the causal agent of anthracnose in avocado fruits, whose characteristic is to remain dormant until the fruit ripens to the maturity consumer stage, when the defense system of the fruit is less active, allowing an easier and more effective infection (Rodríguez-López et al, 2009)
Only 10% of fruits inoculated with C. gloeosporioides and treated with low molecular weight chitosan (LMWC) showed deterioration in quality and the pathogen failed to spread, maintaining a healthy fruit (Figure 3C). These results indicate that LMWC treatment readily increases the avocado fruit resistance against C. gloeosporioides
Summary
The avocado (Persea americana) cv Hass, is from the economic point of view, one of the most important fruits in Mexico because it is the main producer, exporter and consumer of this fruit in the world. RNA-Seq of Avocado Fruit-Chitosan-Colletotrichum and the health of consumers (Brent and Hollomon, 2007) For this reason it is important to seek biological alternatives to the use of fungicides, such as chitosan, which has no polluting characteristics and acts as an elicitor of plant defense responses. RNA-seq analysis has allowed the identification of defense genes induced in orange leaves upon treatment with chitosan, such as different transcription factors and genes involved in some hormone pathways (Coqueiro et al, 2015) In spite of these previous studies, the mechanism by which the chitosan is perceived by the plant and how it induces resistance remains unknown, it is important to design studies that could help shed some light on these processes
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
