Summary of The Modulation of Auxin-Responsive Genes, Phytohormone Profile, and Metabolomic Signature in Leaves of Tomato Cuttings Is Specifically Modulated by Different Protein Hydrolysates
Biostimulant Tomato Cuttings: Root Promotion Through Protein Hydrolysates
Biostimulant Tomato Cuttings are increasingly used to support sustainable horticulture by improving root formation and early plant establishment. In this context, protein hydrolysates (PHs) are recognized as effective biostimulants, as they enhance crop productivity while helping plants cope with environmental stress.
Protein Hydrolysates as Innovative Biostimulants for Tomato Cuttings
Protein hydrolysates obtained from different vegetal protein sources have been widely applied in agriculture. In particular, their use on tomato cuttings has shown clear benefits. Compared to untreated controls, all PH treatments significantly increased both root length and root number. Therefore, these products demonstrate strong root-promoting activity, making them valuable tools for vegetative propagation.
Metabolomic Responses Triggered by Biostimulant Applications
However, the effects of protein hydrolysates are not limited to root morphology. Metabolomic analyses revealed that each treatment induced a distinct molecular signature in leaf tissues. Consequently, different biochemical pathways were activated depending on the botanical origin of the hydrolysate, highlighting the complexity of biostimulant action.
Modulation of Stress-Related Compounds and Hormonal Pathways
Moreover, PH treatments influenced the biosynthesis of key stress-protective metabolites, such as alkaloids and phenylpropanoids. In addition, several metabolites related to phytohormone biosynthesis were significantly affected. Notably, compounds associated with auxin homeostasis were strongly modulated, which is essential for root development and plant growth.
Auxin-Related Gene Regulation in Tomato Cuttings
Furthermore, gene expression analysis supported these metabolic findings. The differential regulation of SlIAA2 and SlIAA9, genes involved in the auxin signaling pathway, suggests an auxin-like activity induced by protein hydrolysates. As a result, signaling cascades originating in leaf tissues may contribute indirectly to enhanced root formation.
Conclusion: Targeted Biostimulant Effects Rather Than a Universal Response
Overall, protein hydrolysates positively influence tomato cuttings at both physiological and molecular levels. Nevertheless, their biostimulant activity is highly specific and depends on the composition and origin of each product. Therefore, rather than inducing a universal response, these biostimulants activate targeted molecular mechanisms that should be further investigated to optimize their use in sustainable agriculture.
