CONICET | Buscador de Institutos y Recursos Humanos

Environmental stress represents a major limitation for increasing crop productivity and the use of natural resources.Most plants are exposed to various types of stress to different degrees and have an inherent ability toadapt to seasonal variations, but when they are subjected to drought and salinity stress, a series of morphological,physiological, biochemical and molecular changes occur. Moreover, both drought and salinity result inosmotic stress, which inhibits growth and causes disturbances at metabolic level. An effect of osmotic stress is theproduction of high levels of reactive oxygen species (ROS). At low concentrations, ROS are essential participantsin cell signaling, but an excess generation of ROS results in toxicity, damaging macromolecules leading to celldeath. To avoid the deleterious effects of ROS and adjust this imbalance, plants have evolved antioxidant systemsthat can be classified as enzymatic and non-enzymatic, and together, these preserve homeostasis in all cellcompartments. In addition, oxidative stress can be measured indirectly following the formation of oxidative byproductsof lipids, proteins, or nucleic acids, with malondialdehyde (MDA) being one of the most widely usedmarkers. It has been observed that the negative effects on plant development caused by water stress can bemitigated by the use of PGPR (Plant Growth Promoting Rhizobacteria) microorganisms, which is an alternativetechnology for improving the capacity of tolerance to abiotic stress in plants. In the present review, byconsidering enzymatic and non-enzymatic responses, we elaborate on the role of PGPR in helping medicinal andaromatic plants to cope with osmotic stress through antioxidant defenses. This review paper also emphasizes afuture research requirement involving investigating the combined utilization of osmotic stress and PGPR in orderto enhance the content of secondary metabolites. In addition, this present review examines the antioxidant responsesin MAPs subjected to osmotic stress and inoculated with PGPR, which have not been extensivelyreviewed before.

enviar mensaje