In Vitro Evaluation and Genome Mining of Bacillus subtilis Strain RS10 Reveals Its Biocontrol and Plant Growth-Promoting Potential

Abstract

Recently, crop management has involved excessive use of chemical fertilizers and pesticides, compromising public health and environmental integrity. Rhizobacteria, which can enhance plant growth and protect plants from phytopathogen, are eco-friendly and have been attracting increasing attention. In the current study, Bacillus subtilis RS10 isolated from the rhizosphere region of Cynodon dactylon, inhibited the growth of indicator strains and exhibited in vitro plant growth-promoting traits. A whole-genome analysis identified numerous biosynthetic gene clusters encoding antibacterial and antifungal metabolites including bacillibactin, bogorol A, fengycin, bacteriocin, type III polyketides (PKs), and bacilysin. The plant growth-promoting conferring genes involved in nitrogen metabolism, phosphate solubilization, hydrogen sulfide, phytohormones, siderophore biosynthesis, chemotaxis and motility, plant root colonization, lytic enzymes, and biofilm formation were determined. Furthermore, genes associated with abiotic stresses such as high salinity and osmotic stress were identified. A comparative genome analysis indicated open pan-genome and the strain was identified as a novel sequence type (ST-176). In addition, several horizontal gene transfer events were found which putatively play a vital role in the evolution and new functionalities of a strain. In conclusion, the current study demonstrates the potential of RS10 antagonism against important pathogens and plant growth promotion, highlighting its application in sustainable agriculture.

Whole-genome analysis revealed the growth-promoting mechanism of endophytic bacterial strain Q2H1 in potato plants

“…We also demonstrated that Q2H1 could solubilize organic phosphate in vitro. Similar to our results, other endophytes, such as Bacillus subtilis RS10 (Iqbal et al, 2021), E. roggenkampii ED5 (Guo et al, 2020), and B. subtilis EA-CB0575 (Franco-Sierra et al, 2020), have also been reported as phosphate solubilizers. Genes related to phosphate transport (pstACS) were found in the genome of B. subtilis strain RS10, which was confirmed in vitro and had favorable plant growth-promoting traits.…”

Genome insights into the plant growth-promoting bacterium Saccharibacillus brassicae ATSA2T

“…3 A, B). Of the eight known BGCs, four [terpenes, carotenoid, siderophore (staphylobactin), and bacillaene] have been well studied and were shown to be directly or indirectly implicated in PGP (Piccoli and Bottini 2013 ; Huang and Osbourn 2019 ; Bottini et al 2004 ; Fiodor et al 2021 ; Masunaka et al 2011 ; Salas-Marina et al 2011 ; Yuan et al 2015 ; Swapnil et al 2021 ; Sulochana et al 2014 ; Lurthy et al 2020 ; Iqbal et al 2021b ). These four BGCs were found between loci 2,036,992 and 2,054,897 bp (total 17,906 bp) for carotenoid, between 3,188,983 and 3,209,900 bp (20,918 bp) for cerecidin, between 904,761 and 925,605 bp (20,845 bp) for siderophore (staphylobactin), and between 537,059 and 626,796 bp (total 89,738 bp) for bacillaene.…”

“…Bacillaene is a polyene synthesized by trans-acyltransferase polyketide synthases via inhibition of prokaryotic protein biosynthesis. Furthermore, this compound has antibacterial activity, which indirectly promotes plant growth (Ji et al 2021 ; Chen et al 2019 ; Iqbal et al 2021b ). Additional research on these secondary metabolites is required to fully elucidate the functions of each metabolite in plant growth.…”

Antagonism of Rhizosphere Streptomyces yangpuensis CM253 against the Pathogenic Fungi Causing Corm Rot in Saffron (Crocus sativus L.)

“…H 2 S can help plants resist various abiotic stresses such as drought, cold, heat, salinity, hypoxia, and toxic metals [ 47 ]. The cysCDHKMNZ gene, which is related to sulfate transport, was also identified in the CM253 genome [ 48 ]. Biofilm formation is the first step in root colonization by rhizosphere bacteria, which can help to mediate plant protection from environmental factors and plant diseases.…”