Microbial Derived Compounds Are a Promising Approach to Mitigating Salinity Stress in Agricultural Crops

Abstract

The use of microbial derived compounds is a technological approach currently gaining popularity among researchers, with hopes of complementing, supplementing and addressing key issues associated with use of microbial cells for enhancing plant growth. The new technology is a promising approach to mitigating effects of salinity stress in agricultural crops, given that these compounds could be less prone to effects of salt stress, are required in small quantities and are easier to store and handle than microbial cells. Microorganism derived compounds such as thuricin17, lipochitooligosaccharides, phytohormones and volatile organic compounds have been reported to mitigate the effects of salt stress in agricultural crops such as soybean and wheat. This mini-review compiles current knowledge regarding the use of microbe derived compounds in mitigating salinity stress in crops, the mechanisms they employ as well as future prospects.

Cell-Free Supernatant Obtained From a Salt Tolerant Bacillus amyloliquefaciens Strain Enhances Germination and Radicle Length Under NaCl Stressed and Optimal Conditions

“…Microbial derived compounds have been reported to enhance plant growth under saline conditions (Naamala and Smith, 2021b). In this study, the effect BA cell-free supernatant on mean radicle length and mean percentage germination varied at different NaCl levels, in corn and soybean.…”

“…(Zhao et al, 2020;Kazerooni et al, 2021;Subramanian et al, 2021). Improvement in technology has allowed for isolation and independent use of pure active compounds, as plant growth stimulants (García-García et al, 2020;Naamala and Smith, 2021b;Subramanian et al, 2021). A series of steps are usually followed before a compound is discovered.…”

Flavonoids and Devosia sp SL43 cell-free supernatant increase early plant growth under salt stress and optimal growth conditions

“…Salinity is an abiotic environmental stress that substantially hinders plant growth, and can have devastating effects on global crop productivity ( Türkan and Demiral, 2009 ; Hasanuzzaman et al., 2013 ; Naamala and Smith, 2021 ). Improper irrigation and poor cultivation practices together with extreme environmental fluctuations are the main contributors to excess salt depositions leading to root-zone salinization.…”

“…As of now, we have just begun to understand the utilization of microbe-based compounds and their importance in plant stress amelioration, however, knowledge in this area is growing, and more interest is developing among those concerned with sustainability. This technology has possible advantages over the direct use of microbial cells, given that they are easy to store and handle, required in minute concentrations, and could bypass limitations that are associated with the use of inoculants ( Naamala and Smith, 2021 ). Microbial compounds have been reported to have growth-stimulating effects even under conditions with extreme environmental limitations ( Fincheira et al., 2021 ).…”

“…Studies on exogenous application of LCOs demonstrated induced resistance to salt stress in an array of plant species including Arabidopsis , soybean ( Subramanian et al., 2016a ), blackgram ( Nandhini et al., 2018 ), and maize ( Nandhini et al., 2016 ; Nandhini and Somasundaram, 2018 ). Interestingly, in addition to these being environmentally friendly technologies, they are reasonably cost and time effective as the reported signal compounds are generall found to perform at their best when applied at very low concentrations ( Naamala and Smith, 2021 ).…”