Authors: Iftikhar Ahmad Muhammad Javed Akhtar Zahir Ahmad Zahir Muhammad Naveed Birgit Mitter Angela Sessitsch
Publish Date: 2014/05/22
Volume: 21, Issue: 18, Pages: 11054-11065
Abstract
Cadmium usually hampers plant growth but bacterial inoculation may improve stress tolerance in plants to Cd by involving various mechanisms The objective was to characterize and identify bacteria that improve plant growth under Cd stress and reduce Cd uptake Cadmiumtolerant bacteria were isolated from rhizosphere soil which was irrigated with tannery effluent and six strains were selected as highly tolerant to Cd showing minimum inhibitory concentration as 500 mg L−1 or 445 mmol L−1 These strains were identified by 16S rRNA gene analysis and functional analysis in regard to plant growth promotion characteristics To determine their effect on cereal growth under Cd stress seeds were inoculated with these strains individually and grown in soil contaminated with three Cd levels 0 40 and 80 mg kg−1 Biomass production relative water content RWC electrolyte leakage ELL and tissue Cd concentration were measured Biomass of both cereals was inhibited strongly when exposed to Cd however bacterial inoculation significantly reduced the suppressive effect of Cd on cereal growth and physiology The bacterial isolates belonged to the genera Klebsiella Stenotrophomonas Bacillus and Serratia Maize was more sensitive than wheat to Cd Klebsiella sp strain CIK502 had the most pronounced effects in promoting maize and wheat growth and lowering Cd uptake under Cd stress
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