Influence of the genus Bacillus bacteria on the content of H₂O₂ and the activity of hydrolases and their inhibitors in potato plants during Phytophthora infestans Mont. de Bary infection

¹ Ufa Federal Research Centre of the Russian Academy of Sciences, Institute of Biochemistry and Genetics, 450054 Ufa, Russia
² Bashkir State University, Faculty of Biology, 450076 Ufa, Russia
³ Institute of Experimental Botany named after V.F. Kuprevich of the National Academy of Sciences of Belarus, Plant Growth and Development Laboratory, 220072 Minsk, Belarus

^* Corresponding author: yarullina@bk.ru

Abstract

The authors studied the effect of treatment with bacteria Bacillus subtilis Cohn (strains 26D) and B. thuringiensis Berliner (strain B-6066) on the hydrogen peroxide (H₂O₂) content, the activity of hydrolytic enzymes and their protein inhibitors in potato plants (Solanum tuberosum L.) in connection with development of resistance to the late blight pathogen - oomycete Phytophthora infestans Mont. de Bary. Studies were carried out on potato plants of the susceptible Early Rose potato cultivar that were treated with a suspension of B. subtilis and B. thuringiensis bacteria (10⁸ cells/ml) and infected with P. infestans (10⁷ spores/ml). A decrease in the degree of leaf damage by oomycete was revealed under the influence of the genus Bacillus bacteria, depending on the strain. The increase in potato resistance to P. infestans infection was mediated by the stimulating effect of the B. subtilis 26D and the B. thuringiensis B-6066 bacteria on the concentration of H₂O₂, the modulating effect on the activity of hydrolytic enzymes and the enhancement of the transcriptional activity of protease and amylase inhibitor genes in plant tissues. Differences in the degree of activation of the transcriptional activity of hydrolase inhibitor genes by the B. subtilis 26D and the B. thuringiensis B-6066 bacteria were revealed, which suggests differential ways of forming the potato resistance to P. infestans under their influence.