Diversity and distribution of endophytic bacterial community in the Noni (Morinda citrifolia L.) plant

Noni (Morinda citrifolia L.) is a plant used by traditional cultures and also in modern health care products. Various chemical substances are derived from the plant and include, but are not limited to anthraquinone flavonol glycosides, iridoid glycosides, lipids glycosides and triterpenoids. Also commonly found on the plant are endophytic bacteria however, there are no reports on endophytic bacterial community of Noni. We collected samples from five sites of Noni plant (roots, branches, leaves, fruits and seeds) and performed 16S rDNA analysis. Results show that these five parts harbor a highly similar bacterial composition with the top four being Sphingomonas, Pseudomonas, Halomonas and Geobacillus. Sphingomonas and Pseudomonas were found to be widely distributed in plant endophytic biotope; while there are little reports on plant-associated Halomonas and Geobacillus, indicating distribution in the plant hosts. Unknown genus also is abundant in five sites of Noni, ranging from 26.70 to 33.66%, implicating necessity to reveal them. This study provides information on endophytic bacteria in the Noni for future analysis based on a metagenome strategy.