Bacterial Plant Biostimulants: A Sustainable Way Towards Improving Growth, Productivity, and Health of Crops

Abstract

This review presents a comprehensive and systematic study of the field of bacterial plant biostimulants and considers the fundamental and innovative principles underlying this technology. Plant biostimulants are an important tool for modern agriculture as part of an integrated crop management (ICM) system; helping make agriculture more sustainable and resilient. Plant biostimulants contain substance(s) and/or microorganisms whose function when applied to plants or the rhizosphere, is to stimulate natural processes to enhance plant nutrient uptake, nutrient use efficiency, tolerance to abiotic stress, biocontrol, and crop quality. The use of plant biostimulants has gained substantial and significant heed worldwide as an environment-friendly alternative for sustainable agricultural production. Presently, there is an increasing curiosity of industry and researchers in microbial biostimulants especially, bacterial plant biostimulants (BPBs) to improve crop growth and productivity. The BPBs that are based on PGPR (plant growth-promoting rhizobacteria) play plausible roles to promote/stimulate the crop plant growth through several mechanisms that include, i) nutrient acquisition by nitrogen (N2) fixation and solubilization of insoluble minerals (P, K, Zn), organic acids and siderophores, ii) antimicrobial metabolites and various lytic enzymes, iii) action of growth regulators and stress-responsive/induced phytohormones, iv) ameliorating abiotic stress like drought, high soil salinity, extreme temperatures, oxidative stress, and heavy metals by using different modes of action, and v) plant defense induction modes. Presenting here is a brief review emphasizing the applicability of BPBs as an innovative exertion to fulfill the current food crisis.

Zinc nutrition and arbuscular mycorrhizal symbiosis effects on maize (Zea mays L.) growth and productivity

“…AMF act as a natural growth regulator for the plant due to its growth stimulation capacity. Many studied focused on its performance in plants and used AMF as bio-fertilizers or bio-inoculants ( Hamid et al, 2021 ). Mycorrhizal fungi secrete glomalin-related soil protein (GRSP) in their mycorrhizosphere, which maintains moisture contents in soil, regulates water translocation from soil to plants.…”

Microbial Biostimulants as Response to Modern Agriculture Needs: Composition, Role and Application of These Innovative Products

“…In the recent years, an increased interest in PGPM-based biostimulants has been observed [ 86 , 87 , 88 ]. In particular, several studies were conducted employing either native or allochthonous PGPMs, and, in some cases, their biostimulant potential was compared [ 77 , 89 , 90 , 91 , 92 , 93 , 94 , 95 ].…”

Psychrotolerant Mesorhizobium sp. Isolated from Temperate and Cold Desert Regions Solubilizes Potassium and Produces Multiple Plant Growth Promoting Metabolites

“…Imbalanced fertilizer application is also a prominent contributing factor to the K deficiency in agricultural soils. These issues have enabled a new research frontier focused on the discovery of an alternative natural, sustainable and safe method for improving K availability by exploring the plant-growth-promoting bacteria (PGPB) that stimulate plant growth through nitrogen (N) fixation, mineral solubilization (phosphorus, potassium and zinc), organic matter degradation, and phytohormone production [ 18 , 19 ]. Among these soil born PGPB, some bacterial candidates have played an influential role in releasing various essential macro and micronutrients from the minerals in large enough quantities to sustain crop growth.…”