Rola bakterii ryzosferowych w stymulacji procesów wzrostu i rozwoju oraz ochronie roślin przed czynnikami środowiska

Abstract

Summary Plant growth promoting rhizobacteria (PGPR) have a positive impact on the growth and development of plants, directly through the production of plant hormones or facilitate nutrient uptake from the environment and indirectly by reducing harmful effect or protection against phytopathogenic organisms. Impact of PGPR on plant growth processes includes increasing the speed of germination, root and shoot growth, an increase in chlorophyll content, magnesium, nitrogen, protein content and hydraulic conductance. These bacteria can also produce antibiotics and hydrogen cyanide, which inhibit the growth of harmful microorganisms in the rhizosphere. Some secrete organic acids, causing an increase in the bioavailability of the trace elements in the soil, other synthesize phytohormones and siderophores. PGPR play a protective role in stress conditions such as drought, salinity, heavy metals, hypoxia, temperature changes and to pathogen's attacks. PGPR strains which stimulate growth and development are known for most crop plants. It seems that the controlled use of PGPR in field crops could potentially contribute to the restriction of the use of chemical fertilizers and herbicides.