Indole acetic acid and flavonoids production by rhizospheric bacteria isolated from Medicago sativa L. rhizosphere

摘要

Rhizospheric region of the roots is richly supplied with the secondary metabolites that orchestrate all sort of rhizospheric interactions and hence communicate plant root with their below-ground competitors. A chemical dialogue is established between the microbes and plant roots that create an atmosphere of complex and dynamic interactions flourishing either symbiosis or pathogenicity. A wide range of secondary metabolites are found there in rhizospheric region but particularly flavonoids and auxins are documented to be the most important signalling elements in plant-microbe interactions. The present work aims to isolate some of the best growth promoting rhizo-bacteria from the rhizosphere of Medicago sativa L. and their potential for secondary metabolites. A total number of 15 different rhizospheric bacterial strains were isolated from the rhizosphere of Medicago sativa L. using L-agar medium. All of these strains were tested for the secretion of Indole acetic acid (IAA) and flavonoids. Three strains were known to be the best producer of IAA and flavonoids. Fifteen different strains in the rhizosphere of just one plant suggest that how diverse they are, and their production of useful secondary metabolites show their importance for the plants.