Genomic functional analysis of the first highly effective Bacillus thuringiensis strain targeting hemipteran pests reveals its plant growth-promoting potential

Abstract

BACKGROUND

Bacillus thuringiensis (Bt) is a multifunctional soil bacterium known for its insecticidal properties. Bt 1012 is the first Bt strain reported worldwide to effectively control hemipteran pests and has outstanding application potential. It was subjected to whole-genome sequencing (WGS), annotation, and functional analysis, with the aim of mining genes responsible for producing putative insecticidal proteins and virulence factors, as well as genes associated with plant growth promotion and root colonization traits.

RESULTS

Bioassay results indicated that Bt 1012 strain and its insecticidal crystals could effectively control the nymphs and adults of Laodelphax striatellus. The WGS results showed that the Bt 1012 genome is 5.72 Mb long with a GC content of 35.29% and contains four small plasmids. The plasmid pBT1012-1 was identified as a key carrier containing insecticidal genes, encoding not only the known mpp64Ba1/mpp64Ca1, but also three new putative insecticidal genes, cry11, vpa2, and vpb4. The strain was also found to encode 75 virulence factors, including several types of enterotoxins, cereulides, immune inhibitor A, and chitinases. Functional gene mining revealed that Bt 1012 has 13 key gene clusters related to plant growth promotion and root colonization features, and these gene clusters are involved in phosphate solubilization, siderophore production, metal chelation, motility, and quorum sensing.

CONCLUSION

This is the first report on the WGS and functional mining of a Bt strain that targets hemipteran pests. This study revealed that Bt 1012 is not just a pesticide with multiple virulence factors, it also has significant potential for plant growth promotion and root colonization, indicating its potential as a biofertilizer. Our findings advance the ongoing search for novel insecticidal toxins and virulence factors while deepening our understanding of the interactions between these beneficial bacteria and plants/insects, providing a scientific foundation for pest control and pathogen suppression strategies. © 2025 Society of Chemical Industry.