Effects on plant physiology in response to inoculation of growth-promoting bacteria: systematic review

Changes in physiological mechanisms resulting from the association of plant growth-promoting bacteria as well as the responses generated to stressful factors are of interest for sustainable agriculture. Based on this, the objective of this study was to gather insights from recent years (2012-2022) on the impacts on plant physiology of the use of inoculants from plant growth-promoting bacteria. To do this, the search for articles was done in three different databases, Science Direct, Springer Nature and Google Scholar, using the following descriptors: plant growth promoting bacteria, plant hormones, biological control, photosynthesis and abiotic stress. After selection, the included articles were systematized in the Excel program. Pearson Correlation and Principal Component Analysis were used for comparative analysis of physiological variables. 81 articles were included in the review, where a beneficial association was observed in 45 plant species distributed in 13 Orders and 13 Families, with emphasis on the Families Poaceae, Fabaceae, Solanaceae and Brassicaceae. 47 genera and 98 bacterial species were verified, where Bacillus and Pseudomonas represented 52% of the verified strains, with emphasis on Bacillus subtilis and Pseudomonas fluorescens. The main applications were growth promotion, productivity, control of biotic stress and abiotic stress. Positive regulation of photosynthesis was observed, modulating the gene expression of photosynthetic apparatus proteins, pigments, antioxidant production, increased hormonal and nutritional production, osmolyte content, antimicrobial production and decreased lipid peroxidation. Based on this review, it was possible to understand the multifaceted role of plant growth-promoting bacteria in contributing to the better direction of technology in agriculture.