Get Together: The Interaction between Melatonin and Salicylic Acid as a Strategy to Improve Plant Stress Tolerance

Both melatonin and salicylic acid (SA) have been demonstrated to play multiple functions in plant physiological processes and biotic and abiotic stress responses. So far, these regulatory molecules have been separately studied despite sharing a common biosynthetic precursor and their similar physiological actions and stress regulation signals. The review published in Agronomy by Hernandez-Ruiz and Arnao entitled "Relationship of melatonin and salicylic acid in biotic/abiotic stress responses" highlights the coincidences and similarities of both regulatory molecules via a thorough literature search and proposes an action model for their interaction in plant stress responses. Despite the undeniable interest and potential impact of this view, it has been focused only on coincident regulatory aspects of SA and melatonin, and the antioxidant-mediated model of interaction that has been proposed is rather speculative and needs to be mechanistically demonstrated. Nevertheless, the mentioned review leads to future research on the melatonin-SA crosstalk to improve biotic and abiotic stress tolerance, which is of utmost importance to ensure food production in the actual age of pandemics and for the upcoming climate crisis scenario.