Rhizobacteria and their contribution to plant tolerance to drought and salinity

Abstract

The positive effect of plant growth promoting rhizobacteria on plants that are subjected to environmental stress has been studied for decades. This review fundamentally deals with aspects related to the theoretical basis of the physiological-biochemical mechanism of these microorganisms, and that have to do with tolerance to drought and salinity by plants, which includes the production of phytohormones, enzymes and osmolytes, among others. Information is also compiled about the progress made on this subject in recent years, in the world and in Cuba, especially in relation to cereals, legumes and grasses. It is considered that water stress, as well as saline stress, limits the growth and productivity of crops, but the use of microbial inoculants highlighted among the ways that exist to reverse the consequences of these stressful environmental factors. Proven results are cited with the application of bioinoculants from rhizobacteria and other beneficial microorganisms that show their usefulness, by increasing the productivity of different crops, under drought and salinity stress conditions. Future researches are needed to develop and apply novel bioinoculants in agriculture so that the threats of drought and salinity can be counteracted. This objective can be achieved through the applied study of plant-microorganism interactions, under environmental stress conditions.
Key words: rhizobacteria, grasses, tolerance, productivity