Variability in stress tolerance and potential of endophytic bacteria to improve chickpea growth under water limited conditions

Abstract

Plant growth promoting bacteria have been employed as a biotechnological tool for ameliorating the impacts of water deficit stress on plants. However, endophytic bacteria colonizing within plant tissues could be of great benefit to the crops. In the present study, forty strains of endophytic bacteria were isolated and tested for their survivability under water deficit conditions. Twelve bacterial isolates showing the highest potential to survive under water deficit conditions were evaluated for inducing stress tolerance in chickpea seedlings at different levels of water deficit stress (i.e.-0.04,-0.70 and-1.24 MPa) under gnotobiotic conditions. Bacterial inoculation with isolates Cs8, Cs10 and Cp7 prominently increased the root length of chickpea over un-inoculated control. Significantly higher root/shoot dry biomass was observed in response to inoculation with bacterial isolates Cs8, Cs10, Cp3 and Cp7 as compared to un-inoculated control. Moreover, all the endophytic bacterial isolates were capable to produce auxins, catalase, oxidase and exopolysaccharides. It is concluded that the endophytic bacteria colonizing internal tissues of pods and shoot of chickpea have better potential to improved growth and biomass of chickpea seedling under reduced water conditions.