AUTHOR=Carletti Paolo , García Andrés Calderín , Silva Carlos A. , Merchant Andrew TITLE=Editorial: Towards a Functional Characterization of Plant Biostimulants JOURNAL=Frontiers in Plant Science VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.677772 DOI=10.3389/fpls.2021.677772 ISSN=1664-462X