Transgenic tomato (Solanum lycopersicum L.) rhizosphere bacterial community structure

The cultivation of genetically modified plants may involve risks to the environment, including soil microorganisms that perform important biospheric functions. The work used transgenic tomato (Solanum lycopersicum L.) of a breeding line obtained from the Yamal variety, with the codA choline oxidase synthesis gene encoding resistance to osmotic stress. Plants of the same breeding line of the original variety used as control. After 20 weeks of cultivation in a soil culture, amplicon sequencing of 16S rRNA of total DNA from the rhizosphere was performed. Analysis of the taxonomic diversity and structure of the bacterial community of the rhizosphere showed an increase in the proportion of the Proteobacteria dominant phylum (from 62 to 64%) and a decrease in Bacteroidetes (from 19 to 17%) in transgenic plants compared with the control. The classes Spartobacteria and Chloroflexia present in control plants were not detected in the rhizosphere of genetically modified plants. Classes Caldilineae and Holophagae absent in the rhizosphere of control plants were detected. Taxonomic analysis at the generic level revealed in genetically modified plants a decrease in the share of the gg Sphingomonas, Rhizomicrobium, Pseudolabris (by 0.6–1.2%) and an increase in the relative abundance of the gg Deviosia and Bauldia (by 1.2–1.3%). The gg Sphingobium and Pedomicrobium present in control plants were undetected in the rhizosphere of transgenic plants, and the gg Micavibrio and Chryseolinea were found out. The Shannon diversity index was 8.62 and 8.77, Chao1 – 1075 and 1122 in control and transgenic plants, respectively. The revealed changes in the composition and structure of the bacterial complex in the rhizosphere of the studied transgenic plants may lead to disruption of the functions of the soil microbial system.