10.22376/ijpbs.2019.10.1.p1-12 Volume 12 Issue 3 2021 (July-September) Plant growth promoting rhizobacteria (PGPR) is a group of bacteria which has the potential for improving plant-growth, development and crop-yield. Research works on the effect and consequences of PGPR on medicinal-plants are still inadequate. Plants reside in a consortium of both beneficial and pathogenic bacterial-strains, hence it's quite important to choose and exploit the most promising rhizobacteria, for desired results in terms of plant growth promotion and productivity. Consequently, this communication is intended for the searching of PGPR-bacteria from the rhizosphere of a less explored plant, lessThan i greaterThan Plumbago zeylanica lessThan /i greaterThan L. Providentially, a bacterial isolate (PLP-1) was found to indulge the plant growth promoting traits to a greater extent than others. Molecular phylogenetic analysis revealed that the bacterium showed the closest match with lessThan i greaterThan Leifsonia shinshuensis lessThan /i greaterThan . The gene bank accession-number of the isolate is KY908321. Subsequent application of lessThan i greaterThan Leifsonia shinshuensis lessThan /i greaterThan in the medicinal host plant, lessThan i greaterThan Plumbagozeylanica lessThan /i greaterThan L. exhibited a good deal by enhancing the seed germination percentage, seedling vigor index, root and shoot growth, number of leaf, dry and fresh weight of the plant when compared with the control. It also improved chlorophyll, sugar and protein content of the plant as well as activity of some defense enzymes proving its involvement for enhancing the oxidative stress tolerance property of this medicinal plant. Also this bacterium can assimilate heavy metals from the soil, so may help the host to withstand the heavy metal stress. This is the first report of lessThan i greaterThan Leifsonia shinshuensis lessThan /i greaterThan (KY908321) to be a potent PGPR which was associated with the ethno medicinally important plant Plumbago lessThan i greaterThan zeylanica lessThan /i greaterThan L. Avishek Sarkar,, Sunanda Dutta,and Sikha Dutta Leifsonia shinshuensis; Plumbago zeylanica L.; Plant Growth Promoting Rhizobacteria; Plant growth enhancement; Seed Germination. 1-12