A.MAXTON, P. SINGH, R. SINGH, A.W. SINGH AND S.A. MASIH
Abstract
PGPR assisted phytoremediation is an environment friendly, cost effective approach for rescuing soil biota health. ACC deaminase enzyme degrades ACC (1 aminocyclopropane-1-carboxylic acid) the immediate precursor of the plant hormone ethylene, into α-ketobutyrate and ammonia, lowers the level of ethylene in stressed plant. During present study, three rhizobacterial strains were isolated and based on morphological, biochemical, molecular characterization, identified as Burkholderia cepacia, Citrobacter freundii and Serratia marcescens. The 16S rRNA gene sequences of same were submitted to GenBank with accession numbers LC169488, LC169489, LC169490 respectively. Screening of rhizobacterial isolates for various plant growth promoting traits revealed that B.cepacia, C.freundii and S.marcescens were capable of various other plant promoting traits. PGPR inoculum of three isolates was inoculated to Capsicum annuum rhizospheric soil with concentrations (0,50,100 and 200 mg/L conc) of Cd, Cr, Pb, then its effects on plant growth was estimated. As revealed by shoot length, root length, number of secondary roots, number of leaves, fresh and dry plant weight, chlorophyll a, b and proline concentration data recorded, Cd was most toxic, having highest whereas Cr exhibited least toxic, inhibitory against plant growth. It was also reported that B.cepacia possessed highest whereas S.marcescens possessed least potential for plant growth promotion under stress.