Harnessing rhizobacteria to fulfil inter-linked nutrient dependency on soil and alleviate stresses in plants

Abstract

Plant rhizo-microbiome comprises complex microbial communities that colonize at the interphase of plant roots and soil. Plant growth-promoting rhizobacteria (PGPR) in the rhizosphere provide important ecosystem services ranging from the release of essential nutrients for enhancing soil quality and improving plant health to imparting protection to plants against rising biotic and abiotic stresses. Hence, PGPR serve as restoring agents to rejuvenate soil health and mediate plant fitness in the facet of changing climate. Though it is evident that nutrient availability in soil is managed through inter-linked mechanisms, how PGPR expedite these processes remain less recognized. Promising results of PGPR inoculation on plant growth are continually reported in controlled environmental conditions, however, their field application often fails due to competition with native microbiota and low colonization efficiency in roots. The development of highly efficient and smart bacterial synthetic communities by integrating bacterial ecological and genetic features provides better opportunities for successful inoculant formulations. This review provides an overview of the interplay between nutrient availability and disease suppression governed by rhizobacteria in soil followed by the role of synthetic bacterial communities in developing efficient microbial inoculants. Moreover, an outlook on the beneficial activities of rhizobacteria in modifying soil characteristics to sustainably boost agroecosystem functioning is also provided.

Functional immune boosters; the herb or its dead microbiome? Antigenic TLR4 agonist MAMPs found in 65 medicinal roots and algae’s

“…The results reported in this work are also in alignment with agricultural studies pertaining to the root bed in plants showing heavy presence of certain microbes “seed to rhizo-micro-biomes”( Neemisha et al, 2022 ; Orozco-Mosqueda et al, 2022 ) which dominate plant growth ( Chang et al, 2022 ; Zhang et al, 2020 ), rigor, fitness, and crop yield ( Abdullaeva et al, 2021 ) Koprivova and Kopriva, 2022 ; Li et al, 2022 ). Microbial communities residing in roots are diverse, some including non – pathogenic B. cereus group, and spp of Enterobacter, Pseudomonas, Cronobacter , with those close to water having the greatest diversity ( Sun et al, 2019 ).…”

Co-inoculation of antagonistic Bacillus velezensis FH-1 and Brevundimonas diminuta NYM3 promotes rice growth by regulating the structure and nitrification function of rhizosphere microbiome

“…Similar to PGPM, co-inoculants also promote plant growth by improving soil nutrient availability, secreting hormones, changing the soil microbial community, and antagonizing ( Olenska et al, 2020 ; Kong and Liu, 2022 ; Luo et al, 2022 ). Some studies have shown that co-inoculants can promote the absorption of nutrients by crops, improve soil enzyme activity, and/or change the structure of the microbial community while promoting the growth of crops ( Hu et al, 2017 ; Moreira et al, 2020 ; Neemisha et al, 2022 ; Sarathambal et al, 2022 ). However, most of these are in vitro studies, and the primary mechanism by which inoculants promotes crop growth in the complex soil systems is still unclear.…”