The application of coir dust modulates the production of phytochemicals in mycorrhizal Passiflora alata Curtis

Abstract

The application of efficient organic substrates and arbuscular mycorrhizal fungi (AMF) is a promising alternative to composing low-cost protocols to enhance the biosynthesis of phenolic and terpenes compounds. These biomolecules from Passiflora alata Curtis extracts have anxiolytic effects relevant to the herbal medicine sector. Therefore, the research aimed to establish an efficient agrobiotechnological protocol applying Acaulospora longula Spain & N.C. Schenck and coir dust to increase the production of foliar bioactive compounds in P. alata. For this purpose, plants were grown for 98 days in a greenhouse, inoculated or not with A. longula, and kept in soil supplied or not with 10% of coir dust. Using these plants, the content of foliar primary and secondary metabolites and mycorrhizal parameters were evaluated. The data were submitted to variance analyses and the means were compared by Tukey's test. We used a clustering algorithm to analyse the similarities. The combined use of coir dust and A. longula added to the substrate favoured the production of total saponins and total tannins, in comparison to non-inoculated passion fruits. Moreover, the use of mycorrhizal biotechnology dismissed the application of coir dust to improve the biosynthesis of total phenols and proanthocyanidins. However, these were not alternatives to enhance the concentration of total flavonoids. The combination of A. longula and coir dust in the cultivation substrate of P. alata provides a high biosynthesis of foliar tannins and saponins, which is enhanced over 70%, being important to the herbal medicine industry of anxiolytics.