Tomato Biostimulant Protein Hydrolysates

Summary of Combining Molecular Weight Fractionation and Metabolomics to Elucidate the Bioactivity of Vegetal Protein Hydrolysates in Tomato Plants

Introduction: Tomato Biostimulant Protein Hydrolysates

Tomato Biostimulant Protein Hydrolysates actively support tomato root growth and overall plant performance. Understanding the bioactive fractions that drive these effects is essential for designing more efficient biostimulants. This study focuses on identifying the most potent fractions of a commercial plant-derived protein hydrolysate (PH) and examining their influence on tomato growth.

Root Development Induced by Tomato Biostimulant Protein Hydrolysates

We tested four PH fractions: PH1 (<0.5–1 kDa), PH2 (>0.5–1 kDa), PH3 (<8–10 kDa), and PH4 (>8–10 kDa). Tomato cuttings received each fraction at three nitrogen levels (3, 30, and 300 mg L−1). Water served as a negative control, while indole-3-butyric acid (IBA) acted as a positive control. Consequently, all PH fractions enhanced root length compared to water. Importantly, PH1 produced the longest roots after foliar application. These results confirm that PH fractions, particularly PH1, efficiently stimulate tomato root growth.

Metabolomic Insights into PH Activity

Next, metabolomics analysis examined the biochemical responses of PH1-treated and full PH-treated plants. The results revealed changes in phytohormones and secondary metabolites that aligned with the auxin-like activity observed in the bioassays. Furthermore, the PH1 response resembled the effects induced by IBA, demonstrating its specific bioactivity. These insights help explain why PH1 improves rooting and overall plant performance.

Implications for Tomato Cultivation

Overall, this study shows that tomato biostimulant protein hydrolysates can enhance root development and trigger beneficial metabolic changes. By using these active fractions, growers can increase productivity, improve crop health, and promote more sustainable tomato cultivation. Importantly, focusing on PH1 allows biostimulant formulations to achieve optimal performance while minimizing unnecessary overuse of the full PH mixture.