Mitigation of abiotic stresses in Lycopersicon esculentum by endophytic bacteria

In this paper, we emphasize the role of endophytic bacterial strains viz. Bacillus subtilis, two strains of Pseudomonas sp. in mitigating drought and salinity stress in tomato plants. Uninoculated or control plants showed arrested growth; while endophytic bacteria inoculated plants had appreciably higher plant biomass and chlorophyll contents under draught and salinity stress. The improving effects of endophytic bacterial inoculation were also substantiated by the augmented water potential and diminished electrolytic leak. Endophytic bacterial treated plants had copiously present K+ and P+ ions while less Na+ ion concentration in contrast to uninoculated under stress. The oxidative stress was reduced by endophytes through lessened activities of total polyphenol and enzymes catalase, peroxidase, polyphenol oxidase, as compared to the uninoculated plants. Uninoculated plants exhibited up-regulation of stress-responsive abscisic acid as compared to endophyte treated plants, while salicylic acid (SA) and gibberellin 4 were considerably higher in endophytic treated plants. In inference, application of endophytic bacterial strains may be used in relegated agricultural lands to upsurge crop sustainability and productivity.