Beneficial effects of weed endophytic bacteria: Diversity and potentials of their usage in sustainable agriculture

Abstract

Plant growth-promoting endophytic bacteria dwell a relatively privileged niche within the host plants and confer beneficial effects to their hosts. These plant probiotics from weed species are poorly explored but possess the tremendous potentials for application in eco-friendly sustainable agriculture. Bacteria from diverse taxonomic genera such as Sinorhizobium, Bacillus, Pseudomonas, Marinorhizobium, Sphingomonas, Sphingobium, Herbaspirillum, Micrococcus, Microbacterium, and Rhodococcus are associated with weed species. Weed-originated plant growth-promoting bacteria (PGPB) exert beneficial effects to their host plants through fixation of atmospheric nitrogen and solubilization of insoluble essential mineral elements (e.g., phosphorus) produce phytohormones (e.g., indole-3-acetic acid), induce systemic resistance (ISR) response to hosts, and secrete antimicrobial substances and other metabolites to protect their hosts from biotic and abiotic stresses. The ISR have tied to disease resistance and abiotic tolerance of plants against drought, cold, salinity, and extreme temperature. As there is no comprehensive review on weed endophytes, this study reviews taxonomic diversity and beneficial effects of weed-associated bacteria and discusses how these natural bioresources could be utilized in agricultural productivity to a new dimension.