Potential direct mechanisms involved in the action of humic substances on plant development

Abstract

The main aim of this communication is to discuss the current knowledge about the potential direct mechanisms that are involved in the beneficial action of humic substances on plant development. To this end, we present and discuss here recent results obtained in our laboratory, along with other findings published by other authors. Finally, we propose a hypothetical whole mechanism for explaining the action of humic substances on plant development. In this schema, we point out those steps that remain unclear.