β-Aminobutyric acid (BABA) priming and abiotic stresses: a review

The use of priming agents in combating the different plants’ abiotic stresses has gained popularity over the years. β-Aminobutyric acid (BABA) is a non- protein amino acid, whose endogenous presence in plant has been lately discovered, is one of such priming agents that are employed for this purpose. While its efficacy against biotic stresses is well established by several pieces of research, its efficacy against abiotic stresses is relatively less pronounced. Although, its ability to independently induce stress tolerance has been reported, modulating plants’ defence system as well as the production of ROS (reactive oxygen species) scavenging antioxidants to mitigate oxidative stresses are still the cardinal points to understanding BABA induced tolerance to abiotic stresses. Some of the changes (physiological, biochemical, molecular) effected by BABA priming against abiotic stresses include accelerated stomatal closure, water use efficiency, photosynthesis enhancement, solute content reorganisation, membrane stability, and stress-responsive gene expression. It is concluded that the effectiveness of BABA against abiotic stresses cannot be overemphasised, however studies regarding its effects against combined stresses and details of its activity, especially at molecular level are still much needed.