Abstract
Under harsh environmental stresses, some plants can survive due to their association with microorganisms. These microorganisms residing within the specific host plant, form unique group of endophytes that can extend diverse sorts of positive impacts on plant. Endophytes related to their functions to host plant and factors affecting their association are poorly studied. Thus, this study concentrated on isolation, identification, and characterization of endophytic bacteria from Heliotropium pterocarpum growing at Hot spring, Gomyqah, Saudi Arabia, for their biological impacts as plant growth promoting (PGP) traits. Seven endophytic bacteria were isolated from root, stem, and leave of H. pterocarpum plant. These bacterial isolates were molecular identified based on 16S rDNA, as Serratia sp., Exigobacterium indicum, Kocuria sediminis, Variovorax paradoxus, Staphylococcus epidermis, Siphingobium yanoikuyae and Serratia rubidea. In addition, 42% of these bacterial isolates have efficacy of phosphate solubilizing with clear zones ranging from 5.2 to 6.6 mm, and siderophore producing ranging from 14 to 16.3 mm. Moreover, most of these bacterial isolates have ability to produce different enzyme activities. Furthermore, all the selected bacterial isolates were able to produce Indole acetic acid (IAA) and Gibberellic acid (GA3) in broth media, ranging from 0.002 to 0.056 mg/ml, and from 0.006 to 0.144 mg/ml, respectively. Considering all these activities of bacterial isolates,endophytes could be exploited as effective resource for promoting plant growth and nutrients uptake without chemical effect on the environment. Thus, endophytic bacteria could be used as biological productin in agriculture fields.