Plant growth promotion and enhanced uptake of Cd by combinatorial application of<i>Bacillus pumilus</i>and EDTA on<i>Zea mays</i>L.

Abstract

In developing countries, Cd contamination is ubiquitous which limits agriculture productivity. The current study was designed to investigate the efficacy of plant-<i>Bacillus pumilus</i>-ethylene diamine tetraacetic acid (EDTA) and plant-microbe-chelator (PMC) synergy for enhanced plant growth and Cd-uptake potential of <i>Zea mays</i> in industrially contaminated and cadmium (Cd) spiked soil. A pot experiment was conducted by growing <i>Z. mays</i> seedlings either inoculated with <i>B. pumilus</i> or un-inoculated along with the application of 5<b> </b>mM EDTA. Plants were exposed to two levels of Cd contamination for 45<b> </b>days. An increase in Cd uptake was observed in <i>Z. mays</i> inoculated with <i>B. pumilus</i> followed by EDTA treatment as compared to non-inoculated and un-treated ones. <i>Zea mays</i> showed improved values with PMC approach for different growth parameters including root length (41%), shoot length (40%), fresh weight (59%), dry weight (49%), chlorophyll contents (49%), and relative water contents (30%). Higher tolerance index (117%) was observed for plants grown in soil spiked with 300<b> </b>mg kg^-1 Cd (S2). PMC application markedly enhanced Cd uptake potential of <i>Z. mays</i> up to 12% and 68.8%, respectively, in S1 and S2 soil. While the PMC application increased Cd accumulation capacity of <i>Z. mays</i> by 71.2% and 52.5% in S1 and S2 soil. The calculated bioaccumulation and translocation factor revealed that <i>Z. mays</i> possess Cd uptake potential, and this ability can be significantly enhanced with PMC application.