Identification, molecular characterization, and plant growth promoting activities of endophytic fungi of Jasminum sambac, Camellia sinensis, and Ocimum basilicum

Abstract

ObjectivesEndophytic fungi are widely known to reside in plant tissues causing no harm to host plants or even no noticeable change. They may colonize host plants for a part of their life cycle or may complete the entire life cycle since host provide a variety of novel metabolites. Despite being in a close relationship with medicinal host plants, the diversity and metabolic spectrum of endophytic fungi have not been researched well. Their diversity and ecological niche as plant symbionts make them attractive targets in the search for novel biochemicals. MethodsWe aimed to isolate, purify, and characterize the endophytic fungal population of medicinal host plants cultivated in Riyadh, Saudi Arabia. The goal was achieved through morphological identification and internal transcribed spacer (ITS) regions in rRNA analyses to determine phylogeny and diversity. Three aromatic and medicinal plants Jasminum sambac, Camellia sinensis, and Ocimum basilicum collected from the Riyadh region, Saudi Arabia were investigated. In total, 84 isolates were purified and they were grouped into 20 operational taxonomic units (OTUs) as per their sequences of ITS regions in rRNA. ResultsTwenty species of endophytic fungi were grouped in 12 genera i.e. Neopestalotiopsis, Trichoderma, Fusarium, Colletotrichum, Myrothecium, Chaetomium, Alternaria, Phoma, Curvularia, Cladosporium, Neodidymelliopsis, and Aspergillus and all isolates belonged to Ascomycota phylum. J. sambac was found dominant among other and had a relative frequency of 27%. C. sinensis was next with 18.7% relative frequency. The diversity was prominently recorded in leaf organs over stem and roots while roots exhibited the lowest diversity. Isolates also produced indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme, and siderophores with variable magnitudes that could be assigned to their wide range of metabolic variations from species to species. ConclusionConclusively, J. sambac, C. sinensis, and O. basilicum are a good source of endophytic fungi with certain plant growth-promoting traits. Overall, Alternaria was found as the most predominant genus in terms of colonization rate. Further deternminations are required to screen the beneficial compounds released by these endophytic fungi.