Plant growth promoting and antagonistic Enterobacter sp. EPR4 from common bean rhizosphere of Garhwal Himalayan inhibits a soil-borne pathogen Sclerotinia sclerotiorum

Abstract

Plant growth stimulating and antagonistic properties of 7 bacterial isolates of beneficial Enterobacter spp. (EPR1- EPR7) screened from the rhizospheric soil of Phaseolus vulgaris plants growing in Garhwal Himalaya, Uttarakhand, India was studied against soil borne phytopathogen Sclerotinia sclerotiorum causes root rots in various crops. Among the isolates, EPR4 showed 64.8% reduction in colony growth of the fungal pathogen in dual culture. All seven isolates are capable of producing Indole Acetic Acid (IAA), but EPR4 also produced cyanogens, solubilized inorganic and organic phosphate, siderophore, ACC (1-aminocyclopropane-1-carboxylic acid) deamininase, and extracellular enzymes like chitinase which inhibited the phytopathogen. For the EPR4 strain, 16S rRNA gene sequencing was followed by NCBI - BLAST similarity showed the maximum sequence similarity (100%) with the species of Enterobacter (available on NCBI data base), and recognized as Enterobacter sp. EPR4 (GenBank accession number JN225424). The Enterobacter sp. EPR4 has the potential to be used as a biocontrol agent against S. sclerotiorum as well as a good plant growth promoter for common bean and other crops grown in India's Garhwal Himalaya.