What Did We Learn From Plant Growth-Promoting Rhizobacteria (PGPR)-Grass Associations Studies Through Proteomic and Metabolomic Approaches?

Abstract

Plant growth stimulation by microorganisms that interact in a mutually beneficial manner remains poorly understood. Understanding the nature of plant-bacteria interactions may open new routes for plant productivity enhancement, especially cereal crops consumed by humans. Proteomic and metabolomic analyses are particularly useful for elucidating these mechanisms. A complete depiction of these mechanisms will prompt researchers to develop more efficient plant-bacteria associations. The success of microorganisms as biofertilizers may replace the current massive use of chemical fertilizers, mitigating many environmental and economic issues. In this review, we discuss the recent advances and current state of the art in proteomics and metabolomics studies involving grass-bacteria associations. We also discuss essential subjects involved in the bacterial plant-growth promotion, such, nitrogen fixation, plant stress, defense responses, and siderophore production.

Brassica Species in Phytoextractions: Real Potentials and Challenges

“…The promotion of root and shoot growth is one of the main effects of PGPR on plants. Various studies report increases in plant total biomass from 20 to 60% after PGPR application [106,107]. However, this effect was not observed in some recent studies on PGPR-enhanced phytoextractions with Brassica species [98,100,104,105].…”

The Contrivance of Plant Growth Promoting Microbes to Mitigate Climate Change Impact in Agriculture

“…Moreover, a very high Na + ion concentration in plant cells results in various physiological disorders, such as reduced flowering or fruiting [13]. The following metabolic processes are very sensitive to increased salinity: transport of electrons, phosphorylation, photosynthesis and photorespiration [48,66]. Salt stress significantly lowers the efficiency of photosynthesis due to its multi-level action.…”

“…Land, as mentioned above, also loses its buffer and antipollution properties [ 56 ]. The long-term salinization process, without any human intervention, results in a drastic decrease in soil fertility, and thus its uselessness [ 66 ]. Increased salt levels not only damage soil structure and microbial activity, but they also limit plant development by generating osmotic impact, hazardous ion and mineral imbalances, or metabolic diseases [ 51 , 67 ].…”

Redox Regulation in Diazotrophic Bacteria in Interaction with Plants

“…Whereas oxidative burst during plant-pathogen interactions has been extensively described, studies concerning the modulation of redox activities in plants interacting with beneficial microbes remain sparse. However, modulation of antioxidant enzyme activities has been observed during some interactions between plants and plant growth-promoting rhizobacteria (PGPR) [15,16]. Analysis of sugarcane root transcriptome showed that many genes involved in the redox process were upregulated and that peroxidase and catalase enzyme activities were also significantly upregulated in response to the Burkholderia anthina MYSP113 [16].…”