Cellular Mechanisms of Inducing Plant Resistance to Stressors by β-Aminobutyric Acid - Cytology and Genetics

Abstract Plant organisms synthesize a variety of nonproteinogenic amino acids, including three isomers of aminobutyric acid: α, β, and γ. β-Aminobutyric acid (BABA) is present in the smallest amounts in plant cells. Its physiological functions and exogenous effects have been primarily studied in the context of plant defense responses against biotic stressors. However, in recent years, data have been accumulated on its ability to induce plant resistance to abiotic stressors of various natures. Nevertheless, these data have been poorly analyzed in the context of BABA’s involvement in signaling processes and the functioning of the plant cell hormonal complex. This review presents information on changes in BABA content in plants in response to stressors of different origins and possible mechanisms for perceiving the signals of this nonproteinogenic amino acid. Its influence on the content of key signaling mediators—reactive oxygen species (ROS), cytosolic calcium, and nitric oxide (NO)—is examined. Information on the interactions between BABA and stress phytohormones—abscisic, salicylic, and jasmonic acids—and their role in plant adaptation to stress factors were analyzed. Data on the effects of exogenous BABA on plant resistance to drought, salinity, heavy metal ions, and extreme temperatures, as well as the state of their main defense systems—antioxidant and osmoprotective—were summarized. The potential applications of BABA in crop production to increase plant resistance to major stress factors are highlighted.