Response of Soil Bacterial Community and Pepper Plant Growth to Application of Bacillus thuringiensis KNU-07

Abstract

Many Bacillus species are among the plant growth-promoting rhizobacteria (PGPR) that promote the growth of many different plant species. This study aimed to investigate the effects of Bacillus thuringiensis KNU-07 on the growth of pepper plants and the soil microbiota. We also designed primers specific for the strain KNU-07 to monitor the population in pepper-cultivated soil. Accordingly, a strain-specific primer pair was designed using a database constructed from 16,160 complete bacterial genomes. We employed quantitative PCR (qPCR) to track the abundance of the strain KNU-07 introduced into pepper-cultivated soil using the strain-specific primers. Our study revealed that the strain was found to possess plant growth-promoting (PGP) activities, and it promoted the growth of pepper plants. The soil bacterial community structure due to the application of the PGPR strain was significantly changed after six weeks post-inoculation. In addition, based on qPCR analysis, the population of the introduced strain declined over time. In this study, application of a PGPR strain increased the growth of pepper plants and changed the soil bacterial community structure. The successful results of monitoring of a bacterial strain’s population using a single strain-specific primer pair can provide important information about the quantification of bio-inoculants under non-sterile soil conditions.

Effects of Bacillus thuringiensis RZ2MS9 on soybean (Glycine max) considering volatile organic compounds, plant development in the field, and soil microbiome diversity

“…thuringiensis strain were reported by Jo et al (2020), and such effect also occurred after six weeks of inoculation, which is consistent with the findings reported here. A similar time interval was seen by Ke et al (2019) In this first study on the co-inoculation of the PGPR strain Bt RZ2MS9 and rhizobia, it was seen that bacterial consortia caused an increase in soybean growth without disrupting soil bacterial diversity over time.…”

“…A previous study with Bt RZ2MS9 showed that this strain is able to produce IAA in the presence of L-tryptophan (BATISTA et al, 2021), which may be attributed to the nature of the strain to utilize L-tryptophan as a physiological precursor (SPAEGEN et al, 2007). Several strains of B. thuringiensis have been used to promote plant growth, and the findings of this study are consistent with those reports (VIDAL-QUIST et al, 2013;TAGELE et al, 2019;VILJOEN et al, 2019;JO et al, 2020).…”

Quorum Sensing System Affects the Plant Growth Promotion Traits of Serratia fonticola GS2

“…Thus, further investigation on the effect of GS2 under real soil rhizosphere is needed in order to determine the production of the QS compounds and PGP potential. Since the inoculation of the strain in the in vivo pot experiment was 10 8 CFU/g soil, it is noteworthy that the inoculant could have an enormous impact on the microbial community, especially in sterilized soil, which in turn could also produce indirect effects in the plant growth ( Jo et al, 2020 ). Hence, the effect of the inoculation of the strain in the soil microbiome remains to be seen.…”

Toward a Sustainable Agriculture Through Plant Biostimulants: From Experimental Data to Practical Applications

“…In addition to seaweed extracts, the use of PGPR such as Bacillus thuringiensis was also considered an efficient approach to boost yield in a sustainable manner. Jo and co-workers [40] inoculation of Bacillus thuringiensis KNU-07 incurred a significant increase of total growth biomass of pepper seedlings. The beneficial effect recorded on inoculated pepper plants was associated with a strong modulation of the soil bacterial community even quantitatively or qualitatively.…”