bacteria include not only the genus Rhizobium, which fall within the
symbiotic relationships with leguminous plants, but also include
some Pseudomonas sp. The importance of PGPR increases when
the soil becomes poor in nitrogen. Then the bacteria can effectively
promote plant growth by providing the limiting element
(Klama et al., 2010). Indirect methods of stimulating plant growth
are based on the reduction or complete elimination of the harmful
effect of phytopathogenic organisms. The pathogen control by
PGPR action involves competition with the ecological niche and
nutrients, while bacteria produce antibiotics and lysis enzymes and
secondary metabolites to combat pathogens. Effective colonization
of PGPR bacteria affects growth and development of plants. The
increasing scale of action towards widespread use of strains which
would include PGPR bacteria in the soil restoration. Such an action
would allow for increased efficiency in the use of biological remediation
of contaminated and degraded areas (Klama et al., 2010;
Glick, 2005).
The aim of the present study was to isolate and characterize
PGPR bacteria associated to grass Agrostis capillaris L., to
evaluate its plant growth promotion mechanisms and to correlate
them with the potential effects on the overall physiology
and survival of the plants in unfavourable conditions, in order
to improve the efficiency of phytoremediation of contaminated