The composition of aromatic compounds in the liquid culture medium and the cells of the Rhizobium leguminosarum bv. viciae , Pseudomonas syringae pv. pisi , and Clavibacter michiganensis sps. sepedonicus bacteria grown in the presence of the negative allelopathic compound N -phenyl-2-naphthylamine (N-PNA) found in the root exudates of legume plants is analyzed. It is demonstrated that phthalates are the main products of N-PNA degradation. Bacteria can actively secrete them into the environment and convert phthalates of one type into other types by changing the alkyl groups linked to the o -phthalic acid via the ester bond in their molecules. The analyzed bacteria differed in the rate of N-PNA degradation (10 and 100 µM), which exerted different effects on their growth and viability. The proposed mechanisms could potentially be used to control the bacterial composition and number in the rhizosphere of legume plants with N-PNA and phthalates secreted by plant roots into the exudates, as well as the phthalates produced in the course of N-PNA degradation in the bacterial cells.

The effect of the bacteria Rhizobium and Pseudomonas on total content of phenolic compounds (PC) and their individual components (apigenin, naringenin, dibutyl-orthophthalate, pisatin, N-phenyl-2-naphthylamine) in the root exudates of the pea seedlings (Pisum sativum L. ) at two different growth stages was studied . Bacteria have similar affect on the total number of PC and the number of constituent apigenine, phthalate and pisatine. Difference at the impact of these bacteria on the content of naringenin and N-phenyl-2naphthylamine was detected, which can be attributed to the peculiarities of the interactions of plants of peas with bacteria-antagonists and mutualists.

It was discovered that aromatic compounds isolated from root exudates of three legume species (Pisum sativum L., Vicia faba L. var. major Hartz, and Glycine max L. MERR) and identified as N-phenyl-2-naphthyl amine, dibutyl, and dioctyl esters of orthophthalic acid, which are known to work as negative allelopathic substances, are involved in the regulation of legume-rhizobial symbiosis formation after the inoculation of roots with rhizobia under unfavorable conditions for symbiosis.