Revealing plant growth-promoting mechanisms of Bacillus strains in elevating rice growth and its interaction with salt stress

Abstract

Soil salinity is a major environmental stress that has been negatively affecting the growth and productivity of rice. However, various salt-resistant plant growth-promoting rhizobacteria (PGPR) have been known to promote plant growth and alleviate the damaging effects of salt stress via mitigating physio-biochemical and molecular characteristics. This study was conducted to examine the salt stress potential of Bacillus strains identified from harsh environments of the Qinghai-Tibetan plateau region of China. The Bacillus strains NMTD17, GBSW22, and FZB42 were screened for their response under different salt stress conditions (1, 4, 7, 9, 11, 13, and 16%). The screening analysis revealed strains NMTD17, GBSW22, and FZB42 to be high-salt tolerant, moderate-salt tolerant, and salt-sensitive, respectively. The NMTD17 strain produced a strong biofilm, followed by GBSW22 and FZB42. The expression of salt stress-related genes in selected strains was also analyzed through qPCR in various salt concentrations. Further, the Bacillus strains were used in pot experiments to study their growth-promoting ability and antioxidant activities at various concentrations (0, 100, 150, and 200 mmol). The analysis of growth-promoting traits in rice exhibited that NMTD17 had a highly significant effect and GSBW22 had a moderately significant effect in comparison with FZB42. The highly resistant strain NMTD17 that stably promoted rice plant growth was further examined for its function in the composition of rhizobacterial communities. The inoculation of NMTD17 increased the relative abundance and richness of rhizobacterial species. These outcomes propose that NMTD17 possesses the potential of PGPR traits, antioxidants enzyme activities, and reshaping the rhizobacterial community that together mitigate the harmful effects of salinity in rice plants.

Salt Tolerant Bacillus Strains Improve Plant Growth Traits and Regulation of Phytohormones in Wheat under Salinity Stress

“…The results showed that key genes responsible for membrane transport, osmotic regulation, regulation of reactive oxygen species, cell signalling and fatty acid and lipid metabolism that enable the bacteria to combat with salt stress were mostly detected in NMCN1 and LLCG23, as compared with FZB42. All these genetic features ( SodA, OpuAC, OPuD , OstB, ComA and DegU) previously reported in the literature were known to play an important role in abiotic stress (Cold and Salt) resilience [ 17 , 20 ]. The whole genome genetic analysis of the halophilic strains (NMCN1 and LLCG23) also showed that the selected strains possess a plethora of genes to combat high salinity stress.…”

“…and Bacillus spp. isolated from saline soil can promote plant growth under saline conditions [ 6 , 17 ]. This idea has attracted the attention of researchers to discover efficient biotechnological approaches involving the application of PGPR as a bio-resource to reduce salinity effects and enhance plant growth under salt stress [ 17 , 18 ].…”

“…isolated from saline soil can promote plant growth under saline conditions [ 6 , 17 ]. This idea has attracted the attention of researchers to discover efficient biotechnological approaches involving the application of PGPR as a bio-resource to reduce salinity effects and enhance plant growth under salt stress [ 17 , 18 ]. Recently, many significant results have been achieved through the application of PGPR for salt stress reduction in wheat plants, leading to enhanced growth and productivity in the saline area [ 16 ].…”

Identification, Phylogeny, Divergence, Structure, and Expression Analysis of A20/AN1 Zinc Finger Domain Containing Stress-Associated Proteins (SAPs) Genes in Jatropha curcas L.

“…For JcSAP gene expression patterns in different plant tissues under abiotic stress, the raw expression data of leaf and root tissues subjected to drought stress was retrieved from the public database of NCBI ( ) (accessed on 11 September 2022) under the GEO accession number GSE61109. The expression profiles of all JcSAP genes were exhibited as reads per kilobase per million (RPKM) values and illustrated via heat map using TBtools [ 30 , 31 ].…”

Genome-Wide Identification and In Silico Analysis of ZF-HD Transcription Factor Genes in Zea mays L.

“…Phylogenetic analysis suggested that ZHDs have expanded considerably during angiosperm evolution [ 1 ]. Biotic and abiotic stresses, such as drought, salinity, heavy metals, high temperatures, heat stress, chilling stress, insects, pathogens, mechanical injury, etc., cause severe damage in terms of kmo, plant growth, development, yield, and quality [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. A well-specialized gene network encodes numerous proteins that systematically control plant growth.…”