Organophosphorus insecticides mineralizing endophytic and rhizospheric soil bacterial consortium influence eggplant growth-promotion

Abstract

This study was aimed to evaluate eggplant's growth-enhancing activity of chlorpyrifos and diazinon-degrading endophytic and rhizospheric soil bacteria isolated from cauliflower and tomato roots and the rhizospheric soil of rice roots, respectively. The identified endophytes belong to the Acinetobacter, Enterobacter and Klebsiella genera, while rhizospheric soil isolates belong to Pantoea, Acinetobacter, Kosakonia, Morganella, Enterobacter, and Klebsiella genera with species variation and genetic distances. All the strain's consumed 100% (50 mg/5 mL) chlorpyrifos and diazinon after 14 days of exposure, except for Pantoea sp. HSTU-Sny4 (84%) and Kosakonia sp. HSTU-ASn39 (42%). The strain's exhibited N-fixation, P-solubilization, indole-3-acetic acid (IAA), and ACC-deaminase production capabilities. The individual strain's and consortium treatment enhanced eggplant growth at germination, seedling, vegetative and reproductive stages. Plant growth-promoting genes, e.g., nif-cluster, chemotaxis, phosphates, sulfur, abiotic stress, chemotaxis, biofilm formation and organophosphorus insecticide-degrading genes were annotated in Klebsiella sp. HSTU-Sny5 and Morganella sp. HSTU-ASny43 genomes. Importantly, the mixed consortium supplemented with 40% urea-treated eggplants demonstrated similar growth parameters compared to the 100% urea eggplants. Plenty of insecticide-degrading proteins belonged to HSTU-Sny5 and HSTU-ASny43 strain's and had interacted with 100 different insecticides as confirmed in virtual screening. This research has a significant role in reducing the application of chemical fertilizer and bioremediation of pesticides in agriculture.