Abstract
The population growth is one of the most important global problems that researchers must overcome. So, application of plant growth promoting rhizobacteria (PGPR) can play a significant role in enhancing the agricultural production through facilitating water and nutrient uptake for plants under various conditions as an important and alternative strategy to overcome overpopulation all over the world. Plant growth promoting rhizobacteria can used as low-cost and environmentally safe biofertilizer to improve crop growth and development by regulating hormonal balance, maintaining nutrients and producing plant growth regulators, however, the chemical fertilizers can harm the ecosystem and human health severely. PGPR treatments may positively affect physiological, biochemical and anatomical features resulting in improve various morphological characters such as number of leaves, leaf area and stem height. Additionally, chlorophyll a and b, carotenoids, relative water content (RWC), antioxidant enzymes and plant hormones as well as crop yield were increased in many plants with the application of PGPR. Moreover, application of PGPR led to improve the anatomical characters of stems and leaves such as stem diameter, lamina thickness, phloem thickness, xylem vessels diameter and number of xykm vessels. Previous studies also reported that PGPR can mitigate the adverse effects of several biotic and abiotic stresses resulted in improve plant growth and yield in many stressed plants. This review article gives an overview on the impacts of PGPR in enhancing morphological, physio-biochemical and anatomical characters through improving the antioxidant enzymes activity, producing plant hormones and consequently crop production.