Salt-tolerant PGPR strain Priestia endophytica SK1 promotes fenugreek growth under salt stress by inducing nitrogen assimilation and secondary metabolites

Abstract

Aims: Soil salinity is a huge obstacle in crop production worldwide. Saline soil can reduce active chemical contents in medicinal plants of the Leguminosae family through crippled normal nodule function. Intensive efforts are underway to improve yield and medicinal value of leguminous herbs under salt stress condition by using benign microbes. Here, an attempt was made to explore the salt-tolerant bacteria associated with rhizosphere of fenugreek plant (Trigonella foenum-graecum L.) and to evaluate their impact on host plant growth and metabolite of pharmaceutical importance. Methods and results:A salt-tolerant plant growth promoting rhizobacterial (PGPR) strain Priestia endophytica SK1 isolated from fenugreek rhizospheric soil, which increased biomass and metabolite content in plants grown under saline stress. SK1 bacterial application induced nodule formation and enhanced nitrogen and phosphorus content under salt (100 mM NaCl) stress as compared to control plants. H 2 O 2 production and lipid peroxidation as a measure of stress were observed high in control plants, while a reduction in these parameters was observed in plants inoculated with SK1. In addition, a significant effect was found on the phenolic compounds and trigonelline content in fenugreek plant inoculated with SK1 bacterium. An increased trigonelline content of about 54% over uninoculated control was recorded under salt stress. Conclusion:The results of this study revealed that the application of salt-tolerant PGPR strain P. endophytica SK1 induced nitrogen fixation machinery that leads to alleviate salt stress and improved the biosynthesis of trigonelline content in fenugreek. Significance of the study:This study extends our understanding on the significance of rhizosphere microbiome and their beneficial role in plant health under environmental stress to promote agro-eco-farming practices.

Priestia Endophytica Bacteria Stimulate Rhodiola rosea L. in vitro Growth

“…In the study of Sharma et al (2022), treatment of plants with Priestia endophytica SK1 bacteria stimulated not only plant growth but also increased nitrogen and phosphorus content, as well as the concentration of phenolic compounds in fenugreek plants. In our experiments, there we no statistical differences in total flavonoid content (p <0.5) and antioxidant activity (p <0.95) in the control and treated plants.…”

“…In particular, it is known that bacteria of the Bacillus genus, which are the component of soil microbiocenosis, are able not only to increase the bioavailability of chemical elements for plants (Kang et al, 2014;Kang et al, 2015a;Yousuf et al, 2017) but also increase the resistance of plants to stress factors and pathogenic microflora (Gururani et al, 2013;Bashir et al, 2021) and synthesize growth-stimulating compounds (Kang et al, 2015b). Such features of plant growthpromoting bacteria are the basis for the development of technologies for the use of these microorganisms to stimulate plant growth, protect them from pathogens and increase resistance to stress factors (Sharma et al, 2022).…”

The Impact of Semi‐Transparent Solar Panels on Tomato and Broccoli Growth

“…[ 33 ] Additionally, trigonelline is involved in the regulation of nitrogen metabolism in plants, serving as a storage and transport form of nitrogen and helping to regulate the availability and distribution within the plant. [ 34 ] It can also be converted into other nitrogenous compounds when needed. [ 35 ] Nevertheless, the most interesting role of trigonelline could be as growth regulator, since it was suggested to regulate auxins, cytokinins, and gibberellins, thereby affecting processes like stem elongation, root development, and overall plant architecture.…”

Plant Growth Promoting Rhizobacteria in Plant Health: A Perspective Study of the Underground Interaction

“…causes a reduction in the ethylene levels and, as such, imparts tolerance to salinity stress [ 57 , 168 ]. In a study, the presence of the Priestia endophytica SK1 in soil with fenugreek plant ( Trigonella foenum-graecum L.) grown was found effective in enhancing nitrogen-fixing ability and improvement in the biosynthesis of trigonelline content [ 169 ]. In another study, inoculation of Acinetobacter johnsonii (SUA-14) to maize resulted in enhancement in the enzymatic activity of urease, alkaline phosphatase in soil and a subsequent decrease in catalase (39%), superoxide dismutase (26%) and malondialdehyde (27%); thereby imparts resistance of maize to salinity stress [ 170 ].…”