Influence of bacterial strains isolated from lead-polluted soil and their interactions with arbuscular mycorrhizae on the growth of Trifolium pratense L. under lead toxicity

Abstract

We isolated two bacterial strains from an experimentally lead (Pb)-polluted soil in Hungary, 10 years after soil contamination. These strains represented the two most abundant cultivable bacterial groups in such soil, and we tested their influence on Trifolium pratense L. growth and on the functioning of native mycorrhizal fungi under Pb toxicity in a second Pb-spiked soil. Our results showed that bacterial strain A enhanced plant growth, nitrogen and phosphorus accumulations, nodule formation, and mycorrhizal infection, demonstrating its plant-growth-promoting activity. In addition, strain A decreased the amount of Pb absorbed by plants, when expressed on a root weight basis, because of increased root biomass due to the production of indoleacetic acid. The positive effect of strain A was not only evident after a single inoculation but also in dual inoculation with arbuscular mycorrhizal fungi. Strain A also exhibited higher tolerance than strain B when cultivated under increasing Pb levels in the spiked soil. Molecular identification unambiguously placed strain A within the genus Brevibacillus. We showed that it is important to select the most tolerant and efficient bacterial strain for co-inoculation with arbuscular mycorrhizal fungi to promote effective symbiosis and thus stimulate plant growth under adverse environmental conditions, such as heavy-metal contamination.

Bio fertilizers and zinc effects on some physiological parameters oftriticaleunder water-limitation condition

“…Sannazzora et al (2005) reported that plants inoculated with Glomus intraradices had higher chlorophyll density than non-mycorrhiza inoculated plants. Vivas et al (2003) showed that inoculation of bacterial strain increased chlorophyll content of lettuce when compared to control. Apparently zinc is involved in the production of chlorophyll.…”

“…Azcon and Barea (2010) have been proposed co-inoculation PGPR and AM fungi as an efficient procedure to increase yield and plant growth. Vivas et al (2003) suggested that there are synergistic effects on plant growth when bacteria (PGPR) and AM fungi are inoculated, particularly under growth-limited conditions. Many researchers have indicated that bio fertilizers can alleviate the unfavorable effects of drought stress on plant growth (Khalafallah and Abo-Ghalia 2008).…”

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

“…inoculation with bio fertilizer as an efficient procedure to increase plant growth. Vivas et al (2003) suggested that there are synergistic effects on plant growth when PGPR and mycorrhiza are inoculated, particularly under growth limited conditions.…”

Allocation plasticity and plant–metal partitioning: Meta-analytical perspectives in phytoremediation

“…The authors wish to thank the Editor-in-Chief and the three anonymous reviewers for this Thlaspi caerulescens Thlaspi ochroleucum Fabacceae Pisum sativum Trifolium pratense Chen & al., 2003;Bi & al., 2003;Vivas & al., 2003 Trifolium repense Li & Christie, 2001; Poaceae Andropogon virginicus Hordeum vulgare Lolium perenne Li & Christie, 2001; Triticum aestivum Zea mays Chen & al., 2004a,b Solanaceae Nicotiana glauca Nicotiana rustica Audet & Charest, 2006 Supplementary Data -2…”