Bacterial insectoacaricides for plant protection: study and prospects of application

Entomopathogenic preparations based on the bacterium Bacillus thuringiensis Berliner (BT) play a key role in the biological protection of plants. The share of BT in the global market of biopesticides is about 90-95%. Specificity, environmental safety and spectrum of action are the features that allow preparations based on this bacterium to occupy an important place among plant protection products. Bacillus thuringiensis is a gram-positive soil bacterium that affects invertebrates. Due to the huge range of hosts, BT has become a leading producer of biopesticides. The entomocidal effect of the bacterium is provided either by toxins containing protein crystals (Cry and Cyt) produced in the stationary phase, or by soluble toxins of the Vip and Sip families secreted by vegetative cells. At the same time, numerous non-toxic virulence factors of BT were found: metalloproteases, chitinases, etc. Bacillus thuringiensis is characterized by poly-enzymatic properties: enzymes from the class of hydrolases have been detected, so the bacterium simultaneously shows activity against harmful insects and phytopathogenic fungi. The antibacterial properties of BT and the ability to stimulate plant growth, inducing a plant protection system against diseases, are noted. Toxicological studies conducted for 50 years around the world have shown the safety of BT and its metabolites, including insecticidal proteins and other substances, which allows them to be widely used in plant protection practice. A new direction in plant protection is the use of transgenic plants based on Bacillus thuringiensis . By introducing BT genes, or rather cry-endotoxin genes into plants, transgenic plants that are resistant to harmful insects are obtained.