Growth and productivity of rice and soil inhabiting microbial population is negatively affected by soil
salinity. However, some salt resistant, rhizosphere competent bacteria improve plant health in saline stress.
Present study evaluated the effect of salt tolerantBacillus amyloliquefaciensNBRISN13 (SN13) inoculation on
rice plants in hydroponic and soil conditions exposed to salinity. SN13 increased plant growth and salt
tolerance (NaCl 200 mM) and expression of at least 14 genes under hydroponic and soil conditions in rice.
Among these 14 genes 4 (NADP-Me2, EREBP, SOSI, BADHandSERK1) were up-regulated and 2 (GIGand
SAPK4) repressed under salt stress in hydroponic condition. In greenhouse experiment, salt stress resulted in
accumulation ofMAPK5and down-regulation of the remaining 13 transcripts was observed. SN13 treatment, with or without salt gave similar expression for all tested genes as compared to control. Salt stress
caused changes in the microbial diversity of the rice rhizosphere and stimulated population of betaine-,
sucrose-, trehalose-, and glutamine-utilizing bacteria in salt-treated rice rhizosphere (SN13þsalt). The
observations imply that SN13 confers salt tolerance in rice by modulating differential transcription in a set of
at least 14 genes. Stimulation of osmoprotectant utilizing microbial population as a mechanism of inducing
salt tolerance in rice is reported for thefirst time in this study to the best of our knowledge