HYDROXAMATE AND CATECHOLATE SIDEROPHORE SYNTHESIZING ARSENIC RESISTANT PGPR ISOLATED FROM WEST BENGAL
Poonam Gusain and Vir Singh
Arsenic has emerged a global environmental problem due to its occurrence in groundwater of sedimentary aquifers. Diverse industrial applications and agriculture practices of arsenic compounds have aggravated the metal contamination problem. Siderophores are specific ferric iron chelator under iron-starved conditions. Two strains WB (Lysinibacillus sp ) and PG (Dietzia maris) showed a high degree of resistance to arsenic upto 1000ppm. Both strains were exhibited battery of plant growth promoting traits including enhanced production of plant growth hormone indole acetic acid (IAA), phosphorus solubilization and siderophore production. Strain WB was found potential IAA producer in the presence of arsenic 1000ppm concentration (67μgl-1). The rate of P-solubilization and siderophore production were obtained maximum in strain PG with 90.0μgml-1 and 81% siderophore units respectively, in arsenic stressed medium. On Infra red screening isolates PG and WB acclaimed hydroxamate and catecholate nature of siderophores respectively. Our results evidenced that the strong pressure in the rhizosphere selected strains able to improve plant fitness by triggering different growth promotory attributes to improve performance upon biotic and abiotic challenges.