• Although early work on increasing salt-tolerance in wheat concentrated on screening existing varieties (e.g. Epstein et al. 1979; Qureshi et al. 1990), the tolerance of wheat relatives to salinity and other stresses has been known for many years.

• Many rhizobacteria produce phytohormones that undoubtedly affect root growth, but efforts to engineer the rhizosphere through hormone manipulation have focused mainly on degradation of so-called stress ethylene, which is synthesized by plants upon exposure to stresses such as flooding, drought, salt, and the presence of metals, organic contaminants and pathogens.

• They suggested that although many of the molecular events are common between chemical stresses and environmental stress of plants at mitochondria proteome level, their extent and significance can vary substantially.