ABA-Degrading Strains of Bacteria of the Genus Pseudomonas and Their Influence on Wheat Growth

Three new representatives of the genus Pseudomonas have been identified that are capable of utilizing abscisic acid and positively influencing the growth and development of plants. Their physiological and biochemical properties have been studied. Based on analysis of the 16S rRNA gene, they were identified as P. veronii IB K11-1 (99.86% similarity) and P. frederiksbergensis IB Ta10m (100%), and strain TaE2 was assigned to Pseudomonas sp. It was found that bacteria, when grown on a mineral-salt medium with ABA, reduced the hormone content by 50–60% with an increase in population density by two orders of magnitude. In a laboratory experiment, it was shown that the introduction of the bacterial biomass (10⁸ CFU/g of substrate) into the rhizosphere of wheat plants ten days after treatment led to a decrease in the abscisic acid content in the roots by 18–30% and an increase in plant weight by up to 30%. Thus, new strains of growth-stimulating ABA-degrading bacteria have been identified and characterized for the first time, which may be promising for the creation of biological products that increase plant resistance to biotic and abiotic stresses.