Amelioration of salinity tolerance in sugar crops using plant growth promoting bacteria

Abstract

Plant growth promoting rhizobacteria (PGPR) occupy the rhizosphere of many plant species and have beneficial effects on the host plant. Cultivated crop plants challenged by salt stress suffer from disturbance of osmotic regulation, ion imbalance, and oxidative stress, which impair plant metabolism and growth. Hereby, the present study was aimed to investigate the potential of plant-growth promoting rhizobacteria (PGPR) to improve the salt stress and alleviate its impact on some sugar crops under different levels of salt concentration. Samples were collected from the rhizosphere of some halophytic plants and the isolation of PGPR was carried out. Two streptomycetes isolates were characterized by classical microbiological techniques, and assessed by molecular identification. Moreover, total cellular proteins were extracted from identified PGPR and SDS-PAGE technique was conducted. Mass spectrometric analysis was also performed to identify PGPR unique polypeptide(s). The results have shown that inoculation of sugar crops, by identified PGPR, has enhanced plant growth parameters under applied salt stress. On the same context, alleviation of salt stress by PGPR inoculation has potentially promoted the accumulation of the major pronounced RuBisCO large subunit protein band