Abiotic stress tolerance induced by endophytic PGPR

Abstract

Abiotic stresses, like shortage of water, soil salinity, and extreme temperatures, are a main treat over worldwide agricultural. Plant Growth Promoter Rhizobacteria (PGPR) refers to several endophytes with alleged positive effects on plant health and growth. Their use has been pursued mainly for agricultural applications to increase yields since three decades. And amongst such purported positive effects is the increase in plants? resistance to abiotic stresses, both by producing some phytohormones and by inhibiting the production of others. However, albeit the considerable amount of literature produce in the meantime the progress either in effective yield increases by inoculation with PGPR or in the understanding of the mechanisms involved in the purported beneficial effects has been rather scarce. This review focusses in revising the advancement made in the study of the different mechanisms involved in PGPR beneficial effects related to the diverse abiotic stresses, and in finding the reason why the limited success in practical application.