Abstract
Despite an increasing interest for the use of biostimulants (BS) in agriculture, methods allowing a precise description of their effects on plants remain rather limited. In the IRIS+ FUI project, two major and highly different worldwide crops, wheat (annual, monocotyledon) and grapevine (perennial, broadleaf) were chosen to deepen our knowledge of such compounds and explore their potential additional interest. One objective was to develop a tool adapted to the screening and study of the impact of a series of BS on the development and physiology of these crops in controlled conditions. We managed to develop such a tool adapted to grapevine herbaceous cuttings. It allows a quite rapid and non-destructive phenotyping of BS effects on the aerial and root parts of plantlets over time. At the end of the experiment, plant material can be sampled for biomass measurements (fresh and dry weight) and analysis of gene expression or metabolites. This tool was validated with some commercial BS prior being used to study new putative ones. Using this tool, we have identified a new BS provided by Arysta-Goëmar. The positive effects of this BS was dose dependent. We have observed that it transiently accelerates the shoot development and increases the number of roots, and also shoot and root biomass. Moreover, analysis of the root and shoot metabolomes highlighted clear fingerprints associated to BS effects. This tool will be useful to screen new BS potentially active in grapevine. Moreover, it will be useful to study and compare the effects of diverse BS on grapevine development, metabolism and physiology ; and to decipher their mode of action. In this context, work is still in progress to further develop this tool to make it suitable to the highlighting of diverse effects related to BS and other crops, such as wheat.