Investigation of the reproducibility of the treatment efficacy of a commercial bio stimulant using metabolic profiling on flax

The choice of an optimal bio stimulant in agriculture is challenging as it depends on the production system implemented, such as the crop, plant model, soil, climate, and farmer’s practices. Thus, understanding bio stimulant–plant interactions at the molecular level using metabolomics approaches is a prerequisite for the development of a bio stimulant, leading to an effective exploration and application of formulations in agriculture. AGRO-K® is a commercialized plant-based bio stimulant that improves vigor and enhances resistance to lodging in cereal crops. A recent previous untargeted metabolomics study has demonstrated the ability of this bio stimulant to improve wheat resistance to lodging in open-field conditions. However, the reproducibility of the effect of this bio stimulant in other field crops has not yet been investigated. Therefore, the present study aimed to assess the changes in primary and secondary metabolites in the roots, stems, and leaves of fiber flax ( Linum usitatissimum L.) treated with AGRO-K®. Concurrent with the previous study conducted in wheat, the present analysis showed that AGRO-K® led to enhancement in the hydroxycinnamic acid amide (HCAA), lignin, and flavonoid pathways in flax. Impacting these pathways enhance root growth and elongation and cell wall lignification, which can aid in preventing crop lodging. These results confirm that HCAAs, flavonoids, and lignin could serve as signature biomarkers of AGRO-K® efficacy in improving lodging resistance for different plant species.