Abstract: Plants during their growth may suffer from many biotic and abiotic stresses, resulting in a decrease of biological production. They may also establish some mechanisms to resist or tolerate the stresses under the stimulation or induction by a variety of factors, among which, plant growth-promoting rhizobacteria (PGPR) is an important one. In this paper, the recently published papers related to this subject were reviewed, and two categories of the action mechanisms of PGPR, namely, induced systemic resistance (ISR) and induced systemic tolerance (IST), were elaborated. The diversity of the action mechanisms of PGPR implied that PGPR could be applied in more agro-ecosystems.

Key words: plant growth-promoting rhizobacteria (PGPR), mechanism, induced systemic resistance (ISR), induced systemic tolerance (IST), progress, saline-alkali ecosystem, cultivated land, remote sensing image interpretation, modified method.