Plant–rhizobacteria interactions alleviate abiotic stress conditions

Abstract

Root-colonizing non-pathogenic bacteria can increase plant resistance to biotic and abiotic stress factors. Bacterial inoculates have been applied as biofertilizers and can increase the effectiveness of phytoremediation. Inoculating plants with non-pathogenic bacteria can provide 'bioprotection' against biotic stresses, and some root-colonizing bacteria increase tolerance against abiotic stresses such as drought, salinity and metal toxicity. Systematic identification of bacterial strains providing cross-protection against multiple stressors would be highly valuable for agricultural production in changing environmental conditions. For bacterial cross-protection to be an effective tool, a better understanding of the underlying morphological, physiological and molecular mechanisms of bacterially mediated stress tolerance, and the phenomenon of cross-protection is critical. Beneficial bacteria-mediated plant gene expression studies under non-stress conditions or during pathogenic rhizobacteria-plant interactions are plentiful, but only few molecular studies on beneficial interactions under abiotic stress situations have been reported. Thus, here we attempt an overview of current knowledge on physiological impacts and modes of action of bacterial mitigation of abiotic stress symptoms in plants. Where available, molecular data will be provided to support physiological or morphological observations. We indicate further research avenues to enable better use of cross-protection capacities of root-colonizing non-pathogenic bacteria in agricultural production systems affected by a changing climate.

Survey of Plant Drought-Resistance Promoting Bacteria from Populus euphratica Tree Living in Arid Area

“…Plant growth-promoting bacteria (PGPB) exert beneficial effects on various plants and play an important role in plant growth promotion, biological control and also resistance to abiotic stress [1][2][3]. PGPB promote growth of plants in a variety of environments by direct and indirect mechanisms.…”

Properties of the halophyte microbiome and their implications for plant salt tolerance

“…The beneficial effects provoked by endophytes result from nitrogen fixation, phytohormone production, supply of nutrients and pathogen suppression (Rosenblueth and Martinez-Romero 2006;Hardoim et al 2008) and those mechanisms also account for the alleviating effects of microorganisms when host plants face unfavourable environmental conditions. Two recent reviews are devoted to the protective microbial processes conferring abiotic stress tolerance to plants (Dimkpa et al 2009;Dodd and Perez-Alfocea 2012). Halophytic plants harbour a variety of micro-organisms and in the following we summarise the contribution of micro-organisms to salt tolerance in this specific plant group.…”

Effect of Zinc and Bio Fertilizers on Antioxidant Enzymes Activity, Chlorophyll Content, Soluble Sugars and Proline in Triticale Under Salinity Condition

“…The response of plants to salinity depends on several factors such as developmental stage, severity, duration of stress, and cultivar genetics. Salinity also causes oxidative damage as a consequence of producing large Dimkpa et al (2009) reported that rhizosphere microorganisms, exclusively beneficial bacteria and fungi, can improve plant performance under stress environments and enhance yield. The use of PGPR may be proper in developing strategies to facilitate plant growth in saline soils (Vessy, 2003).…”