Analyzing the Hemp Microbiota

Plants are naturally associated with microorganisms' communities (microbiotas), which have a significant influence on the plant phenotype, extending its genetic potential and conferring essential traits for growth, resilience, and health. Within these microbiotas, bacterial endophytes are of particular relevance due to their widely distributed plant growth-promoting (PGP) activities and their capacity to synthesize secondary metabolites. These features make them promising candidates for biotechnological applications, particularly the development of bioinputs (biofertilizers, biostimulants, and biopesticides), aimed at reducing dependence on chemical inputs in agriculture. Current hemp (Cannabis sativa) cultivation practices rely heavily on chemical inputs, generating economic, environmental, and social challenges. This study reports the construction and characterization of a collection of endophytic bacteria associated with healthy plants and seeds of the hemp cultivar Luma, a crop cultivated in Uruguay primarily for fiber production. A total of 236 bacterial isolates were obtained from surface-disinfected seeds, seedlings, roots, and aerial tissues, confirming their status as putative endophytes. Of these, 66% of the isolates exhibited at least one of the 5 PGP traits tested, including nitrogen fixation, mineral solubilization, and phytohormone production. Genera with recognized PGP potential, such as Bacillus and Pseudomonas, were particularly abundant in seeds and roots, respectively. Notably, this is the first report describing the association of Mycolicibacterium and Aminobacter strains with cannabis plants. This work represents a first step toward developing bioinputs tailored to the Uruguayan cannabis industry and highlights the broader promise of endophytes for sustainable agricultural practices.