Endophytic Bacteria from Passiflora incarnata L. Leaves with Genetic Potential for Flavonoid Biosynthesis

Passiflora incarnata, a member of Passifloraceae family, is a traditional herb widely used as medicine since ancient times. It has extensive medicinal uses because of its high flavonoid content. Due to the high degree of interactions between endophytic bacteria and plants, it is believed that these microorganisms can produce metabolites initially produced by their host. Based on this hypothesis, the objective of this work was to analyze the genetic potential for flavonoid production of endophytic bacteria isolated from passion fruit plants, applying a PCR-based approach with genus-specific primers. Twenty strains from ten species within the genus Sphingomonas were tested for presence of the flavonol synthase (FLS) gene. The primers used effectively detected the FLS gene in all strains, but in two species, nonspecific bands appeared. A phylogenetic tree was constructed to evaluate the distribution of the gene among the strains used in this work. Phylogenetic analyses suggests that horizontal gene transfer (HGT) events occurred among various strains. This work may contribute to further research efforts aiming at the production of flavonoids by endophytic bacteria, based on the ability of these microorganisms to acquire genes from their hosts.