Control of Drought Stress in Wheat Using Plant-Growth-Promoting Bacteria

Abiotic stress conditions are the main limiting factors for crop cultivation around the world. In the present study we aimed to improve wheat growth under drought stress conditions through priming with beneficial bacteria considered as plant-growth promoting bacteria (PGPB). Two bacterial strains, Bacillus amyloliquefaciens 5113 and Azospirillum brasilense NO40, were used to prime the wheat cv. Sids1. To generate drought stress for 12-day-old seedlings, water was withheld for 4, 5, or 7 days while growth and survival were recorded. Furthermore, several stress markers were examined by molecular and biochemical assays to study the role of priming on different stress tolerance mechanisms. Priming significantly alleviated the deleterious effect of drought stress on wheat. Drought resulted in the upregulation of some stress-related genes (APX1, SAMS1, and HSP17.8) in the leaves and increased activity of enzymes involved in the plant ascorbate-glutathione redox cycle. Bacteria-treated plants showed attenuated transcript levels suggesting improved homeostatic mechanisms due to priming. The present study reports on the ability of certain PGPB to attenuate several stress consequences in plants which strongly supports the potential of such an approach to control drought stress in wheat.